CN103827071A

CN103827071A - Process for preparation of methacrylic acid and methacrylic acid esters

Info

Publication number: CN103827071A
Application number: CN201180073459.9A
Authority: CN
Inventors: H·舍费尔; T·巴尔多夫
Original assignee: Evonik Roehm GmbH
Current assignee: Evonik Roehm GmbH
Priority date: 2011-09-16
Filing date: 2011-09-16
Publication date: 2014-05-28
Also published as: TWI627161B; SG2014012587A; SA112330845B1; JP6008969B2; CN108373409A; WO2013037134A1; KR20140060528A; MY161504A; TW201329035A; JP2014528935A; KR101877597B1

Abstract

The invention relates to a process for preparation of at least one of methacrylic acid and a methacrylic acid ester, comprising process steps: a1) gas phase oxidation of at least one C4 compound to obtain a reaction phase comprising methacrylic acid; a2) quenching of the reaction phase to obtain a crude aqueous phase comprising methacrylic acid; a3) extraction of at least a part of the methacrylic acid from the crude aqueous phase comprising methacrylic acid into an organic solvent to obtain a crude organic phase comprising methacrylic acid and a first aqueous phase, wherein the first aqueous phase comprises components: i. at least 65 wt.%, preferably in the range of from 65 wt.% to 99.9 wt.%, more preferably in the range of from 70 wt.% to 99.8 wt.% water, yet more preferably in the range of from 75 wt.% to 99 wt.%, more preferably in the range of from 76 wt.% to 98.5 wt.%, more preferably in the range of from 77 wt.% to 98 wt.%, even more preferably in the range of from 78 wt.% to 97.5 wt.%, even more preferably in the range of from 79 wt.% to 95 wt.%, yet more preferably in the range of from 80 wt.% to 90 wt.% water, based on the total weight of the first aqueous phase, and ii. not more than 35 wt.%, preferably in the range of from 0.1 wt.% to 35 wt.%, preferably in the range of from 0.2 wt.% to 30 wt.%, more preferably in the range of from 1 wt.% to 25 wt.%, yet more preferably in the range of from 1.5 wt.% to 24 wt.%, more preferably in the range of from 2 wt.% to 23 wt.%, even more preferably in the range of from 2.5 wt.% to 22 wt.%, even more preferably in the range of from 5 wt.% to 21 wt.%, yet more preferably in the range of from 10 wt.% to 20 wt.% of at least one organic compound, based on the total weight of the first aqueous phase, wherein the sum of the weight amounts of i. and ii. is 100 wt.%; a4) separation and optionally purification of at least a part of the methacrylic acid from the crude organic phase comprising methacrylic acid; a5) optionally, esterification of at least a part of the methacrylic acid obtained in step a4); b) separation of at least a part of the water comprised in the first aqueous phase obtained in step a3) from at least a part of at least one component ii. to obtain a second aqueous phase and an organic phase, wherein the organic phase comprises at least one component ii., and wherein the second aqueous phase is depleted in at least one component ii. compared to the first aqueous phase; c) optionally, separation of at least a part of at least one organic compound from the second aqueous phase obtained in process step b) to obtain a third aqueous phase; d) optionally, separation of at least a part of at least one component ii from the organic phase obtained in process step b), to a process for treatment of an aqueous phase comprising at least one organic compound, and a device for production of at least one of methacrylic acid and a methacrylic ester.

Description

The preparation method of methacrylic acid and methacrylic ester

Technical field

The present invention relates to the preparation method of methacrylic acid, the treatment process of the preparation method of methacrylic ester and the water that comprises at least one organic compound.

Background technology

Methacrylic acid (MAA) and methacrylic ester, for example methyl methacrylate (MMA) and butyl methacrylate, for various application.The industrial production of the methacrylic acid especially gaseous oxidation of the heterogeneous catalyst by iso-butylene, the trimethyl carbinol, Methylacrylaldehyde or isobutyric aldehyde is carried out.By cooling and condensation, such obtained vapor reaction is transformed into methacrylic aqueous acid mutually, optionally separate with lower boiling material for example acetaldehyde, acetone, acetic acid, propenal and Methylacrylaldehyde, then introduce solvent extraction tower, to utilize applicable extraction agent, for example short hydrocarbon, extraction and fractionation methacrylic acid.Separated methacrylic acid is further purified, and for example, by distillation, to separate high boiling impurity, for example phenylformic acid, toxilic acid and terephthalic acid, to obtain pure methacrylic acid.This kind of known method is for example described in EP0710643, US4, in 618,709, US4,956,493, EP386117 and US5,248,819.

This kind of known method produces a large amount of waste water at each operation stage, and in them, maximum is in water form residual after quenching extracts methacrylic acid mutually.Water is mainly from steam or the water of interpolation that enters gaseous oxidation step, and the use as the quenchant in cooling and condensing steps from water, and carrys out automatic oxidation reaction itself.This waste water contains quite a large amount of organic compound and can not re-use or throw aside safely to remove at least in part these organic compound in the situation that not further not processing.This type of organic compound generally includes for example methacrylic acid of desirable product (owing to being not exclusively extracted in organic extractant), and other by product of oxidation step for example vinylformic acid, acetic acid and propionic acid, and they also have commercial value.Organic content in this waste water generally too high and not can with the processing of water technology biological example, for example activated-sludge method is compatible and do not require significant dilution, considerable time and very large treatment facility, so that in business methacrylic acid is produced, often make this waste water burning, for example, US4, described in 618,709.But, the burning of waste water is on environment and be all disadvantageous economically, requires high-energy input, causes may requiring before being discharged in environment the discharge of further processing, cause being in addition present in the loss of the potential valuable organic compound in waste water, and the loss of water itself.

Can reclaim at least in part the organic compound being present in waste water therefore can be favourable.Also will be advantageous that at least some of recycle-water itself, or there is for its experience biological treatment and/or for being discharged in environment enough low organic content, or be this water and be enough to re-use, for example, as industrial technology water or for methacrylic acid/methyl methacrylate preparation technology's purity itself.CN1903738 has proposed to use membrane separation apparatus to follow waste water acrylic acid, toluene and acetic acid that rectifying tower is produced from vinylformic acid with purifying.Generally speaking the shortcoming of membrane filtration is, requires a large amount of water (often using waste water itself) to rinse out the not component by strainer.Then the washing water of this organic compound substrate concentration with increase itself must further be processed or burning.

In addition, wide variety of method steps, especially methacrylic acid from moisture quenching mutually, extract after the general fractionation by distillation of methacrylic acid and extraction agent, cause forming as the methacrylic acid phase of overhead product with as residue and (be sometimes referred to as bottom phase, distillation leftover or waste oil) higher-boiling compound phase, it still contains a large amount of methacrylic acids.At least some that can reclaim mutually this methacrylic acid from higher-boiling compound will be favourable.The whole bag of tricks has been advised in processing for this kind of higher-boiling compound phase.

EP1043302 has proposed with the solvent treatment waste oil that acid is produced from acrylic or methacrylic, to prevent polymerization and/or the generation of throw out in waste oil of waste oil.US2005/0054874 discloses in acrylic or methacrylic acid is synthetic the high boiling point heavy ingredient of discharging from each step classification by their acrylic or methacrylic acid content, and by they and the high boiling point from other commercial run are merged to process them mutually, so that they can store in the situation that there is no solid precipitation.But, in the arbitrary piece of writing in these documents, all do not instruct from waste oil and reclaim methacrylic acid.

Summary of the invention

Object of the present invention is usually the shortcoming that overcomes as far as possible art methods.

Another object is the overall yield that increases methacrylic acid and/or methyl methacrylate preparation method by reclaim mutually methacrylic acid from higher-boiling compound.

Another object is to increase methacrylic acid preparation method's overall efficiency and/or productive rate by reclaiming organic compound from processing wastewater.

Another object of the present invention is can re-use from this waste water reclamation water so that this water by reducing as far as possible processing wastewater to be subject to orgnic compound pollution, experience biologically pure process, or be discharged into environment, optionally after the purge process of biology or other type, be discharged into environment, rather than incinerate together with organic compound.

Made by the preparation method of at least one in methacrylic acid and methacrylic ester for the contribution that solves above-mentioned purpose, the method comprises following methods step:

A1) at least one C ₄the gaseous oxidation of compound is to obtain the reacting phase that comprises methacrylic acid;

A2) quenching of described reacting phase is to obtain the thick water that comprises methacrylic acid;

A3) at least a portion of described methacrylic acid is extracted into organic solvent from the described thick water that comprises methacrylic acid, to obtain the thick organic phase that comprises methacrylic acid, and the first water, wherein said the first water comprises following component

I. at least 65 % by weight, preferably 65 % by weight-99.9 % by weight, more preferably 70 % by weight-99.8 % by weight water, more more preferably 75 % by weight-99 % by weight, more preferably 76 % by weight-98.5 % by weight, more preferably 77 % by weight-98 % by weight, even more preferably 78 % by weight-97.5 % by weight, even more preferably 79 % by weight-95 % by weight, more more preferably 80 % by weight-90 % by weight water, based on the gross weight of described the first water, and

Ii. be no more than 35 % by weight, preferably 0.1 % by weight-35 % by weight, preferably 0.2 % by weight-30 % by weight, more preferably 1 % by weight-25 % by weight, more more preferably 1.5 % by weight-24 % by weight, more preferably 2 % by weight-23 % by weight, even more preferably 2.5 % by weight-22 % by weight, even more preferably 5 % by weight-21 % by weight, more more preferably at least one organic compound of 10 % by weight-20 % by weight, based on the gross weight of described the first water

Wherein the weight amount sum of i. and ii. is 100 % by weight;

A4) separating and purifying optionally of at least a portion of described methacrylic acid and the thick organic phase that comprises methacrylic acid;

A5) optionally, step a4) in the esterification of at least a portion of the described methacrylic acid that obtains;

B) be included in step a3) in the separating of at least a portion of water in the first water of obtaining and at least a portion of at least one component ii., to obtain the second water, and organic phase, wherein said organic phase comprises at least one component ii., with wherein said the second water compared with the first water dilution at least one component ii.;

C) the second water that optionally, at least a portion of at least one organic compound and method steps obtain in b) separate to obtain the 3rd water;

D) optionally, at least a portion of at least one component ii. and b) separating of the middle organic phase obtaining of method steps.

Also made by the treatment process of the water that comprises at least one organic compound for the contribution that solves above-mentioned purpose, the method comprises following methods step:

A) provide the first water that comprises following component

Ii. be no more than 35 % by weight, preferably 0.1 % by weight-35 % by weight, preferably 0.2 % by weight-30 % by weight, more preferably 1 % by weight-25 % by weight, more more preferably 1.5 % by weight-24 % by weight, more preferably 2 % by weight-23 % by weight, even more preferably 2.5 % by weight-22 % by weight, even more preferably 5 % by weight-21 % by weight, more more preferably at least one organic compound of 10 % by weight-20 % by weight, based on the gross weight of described the first water;

Wherein the weight amount sum of i. and ii. is 100 % by weight;

What b) be included at least a portion of water in the first water that method steps provides in a) and at least a portion of at least one component ii. separates to obtain the second water and organic phase, wherein said organic phase comprises at least one component ii., with wherein said the second water compared with the first water dilution at least one component ii.;

At the step a1 of the method according to this invention) in experience gaseous oxidation C ₄compound is preferably selected from the C of iso-butylene, the trimethyl carbinol, isobutyric aldehyde and Methylacrylaldehyde ₄compound, or two or more mixture in them.Of the present invention one preferred aspect in, C ₄compound stems from the division of methyl tertiary butyl ether (MTBE) or Ethyl Tertisry Butyl Ether (ETBE).

The step a1 of the method according to this invention) in gaseous oxidation preferably under at least one oxide catalyst exists, carry out.If C ₄compound is iso-butylene or the trimethyl carbinol, can in a step, carry out in order to obtain containing the gaseous oxidation of the gas phase of methacrylic acid, one of them step is considered to refer to that initial oxidation becomes the Methylacrylaldehyde oxidation step of going forward side by side to become the process of methacrylic acid substantially in same reaction zone, under at least one catalyzer exists, to carry out in this article.Alternative, step a1) in gaseous oxidation can be in more than one step, preferably in two steps, preferably in two or more reaction zones separated from one another, carry out, wherein preferably there are two or more catalyzer, every kind of catalyzer be preferably present in another catalyzer reaction zone separated from one another in.In two step gaseous oxidations, first step is C preferably ₄compound is oxidized to Methylacrylaldehyde at least partly, and then Methylacrylaldehyde is oxidized to methacrylic acid at least partly.Therefore, for example, in the first reactions steps, preferably exist and be suitable at least one C ₄compound oxidation becomes at least one catalyzer of Methylacrylaldehyde, and in the second reactions steps, has at least one catalyzer that is suitable for Methylacrylaldehyde to be oxidized to methacrylic acid.

The applicable reaction conditions of catalytic gas phase oxidation is, for example, about 250 ℃-about 450 ℃, the temperature that preferably approximately is 250 ℃-about 390 ℃, and about 1 normal atmosphere-about 5 atmospheric pressure.Space velocity can be about 6000/ hour of about 100-(NTP), about 3000/ hour of preferably approximately 500-.C ₄for example iso-butylene is to the oxidation of Methylacrylaldehyde and/or methacrylic acid for raw material, and for example catalytic gas phase oxidation, and catalyzer used is known in the literature, for example, from US5,248,819, US5,231,226, US5,276,178, US6,596,901, US4,652,673, US6,498,270, US5,198,579, US5,583,084 is known.

Be suitable for iso-butylene or Oxidation of t-Butanol to become the especially preferred Catalyst And Method of Methylacrylaldehyde and/or methacrylic acid to be described in EP0267556, the especially preferred Catalyst And Method that is suitable for the Methylacrylaldehyde to be oxidized to methacrylic acid is described in EP0376117.These documents are accordingly as the part with reference to introducing and be formed as the disclosure of invention.

In the method according to this invention Methylacrylaldehyde to the gaseous oxidation of methacrylic acid preferably in about about 350 ℃ and following temperature of 250-, under about about 3 atmospheric pressure of 1-, and carry out under the volume load of about about 1800Nl/l/h of 800-.

As oxygenant, conventionally use oxygen, for example, be air form, or be pure oxygen or for example, oxygen form with the gas of at least one inertia under reaction conditions (at least one in nitrogen, carbon monoxide and carbonic acid gas) dilution, wherein air preferably as oxygenant and nitrogen and/or carbonic acid gas preferably as diluent gas.If carbonic acid gas as diluent gas, it is preferably from the burning of reactant gases and/or by product, the carbonic acid gas of preferred catalytic or hot burns recirculated.Experience is according to the step a1 of the inventive method) in the gas of gaseous oxidation preferably also comprise water, it is conventionally water vapour form and exists.Can be before gas-phase reaction or during, or before gas-phase reaction and during, oxygen, one or more rare gas elementes and water are introduced to reacting phase or and C ₄compound combination.

In a preferred embodiment of the method according to this invention, by the mixture supplying step a1 that comprises following material): at least one C ₄the oxidation reactor Exhaust Gas of compound, air or oxygen and recirculation, the oxidation reactor Exhaust Gas preferably having burnt before recirculation.Described reactor Exhaust Gas preferably comprises at least one unreacted C ₄compound, at least one oxycarbide, nitrogen and oxygen, and water, this depends on existence and the effect of separation condition and combustion step.

In two step gaseous oxidations according to the present invention, the C in first step ₄compound: O ₂: H ₂o: the preferred volume ratio of rare gas element is generally 1:0.5-5:1-20:3-30, preferably 1:1-3:2-10:7-20.Methylacrylaldehyde in second step: O ₂: H ₂o: preferably 1:1-5:2-20:3-30 of the volume ratio of rare gas element, preferably 1:1-4:3-10:7-18.

According to the step a2 of the inventive method) in, the cooling and condensation (being commonly referred to as quenching) of the gas phase that makes to comprise methacrylic acid and obtain the condensation product that is the thick aqueous solution form that comprises methacrylic acid.Condensation can be by well known by persons skilled in the art and seem that any means that are applicable to carry out, for example by by be cooled to containing the gas phase of methacrylic acid lower than in its component at least one dew point, particularly water and methacrylic acid at least one the temperature of dew point.Applicable method of cooling is well known by persons skilled in the art, for example, utilize at least one interchanger cooling, or by quenching, for example, by using liquid, for example water, waterborne compositions or organic solvent, for example, be selected from the organic solvent of aromatics or aliphatic hydrocrbon, or the mixture of at least two kinds in them, spray described gas phase, wherein preferred organic solvent has compared with low-vapor pressure under quenching conditions, for example heptane, toluene or dimethylbenzene, wherein water is preferably as according to quench liquid of the present invention, and at least a portion of the condensation product forming in quench step itself even more preferably.Applicable method of quenching is well known by persons skilled in the art, for example, from DE2136396, EP297445, EP297788, JP01193240, JP01242547, JP01006233, US2001/0007043, US6,596,901, US4,956,493, US4,618,709, US5,248,819 know, a part for present disclosure is introduced and be formed as to their disclosure that relates to vinylformic acid and methacrylic acid quenching accordingly.Preferably gas phase be cooled to the temperature of 40-80 ℃ according to the present invention and obtain and comprise methacrylic aqueous acid with deriving from the water of quench step and/or condensation product washing, this aqueous solution can also comprise impurity for example acetic acid, toxilic acid, fumaric acid, citraconic acid, vinylformic acid and the formic acid of different amounts, and aldehyde for example formaldehyde, acetaldehyde, propionic aldehyde, propenal, Methylacrylaldehyde, ketone and unreacted one or more C ₄compound.These impurity and water need maximum possible degree separate to obtain highly purified methacrylic acid with methacrylic acid.

At least a portion of described methacrylic acid from the extraction containing the thick aqueous solution of methacrylic acid at method steps a3) utilize organic extractant, for example, at least one organic solvent, preferably at least one carries out with the immiscible organic solvent of water substantially, so that can form water and organic phase.Method steps a3) also comprise separated from one another to described water and organic phase.Can be different from the boiling point of methacrylic acid for having according to the preferred organic solvent of the step c) of the inventive method, preferably than its lower boiling point.Preferably, in the method according to the invention, method steps a3) in the organic extractant that uses there is the boiling point that is less than 161 ℃ of under atmospheric pressure measuring.Described organic extractant then can be in principle according to the step a4 of the inventive method) in separate with methacrylic acid, for example, by distillation, preferably at least in part, preferably, to separate to a large extent, wherein it is preferably removed in the position higher than pure methacrylic acid in distiller as low-boiling-point substance at least in part.The guiding of separated organic extractant or its part can be got back to method steps a3), optionally after and/or purification step cooling at least one.The preferred organic solvent of this step is especially selected from alkane and aromatics, and the hydrocarbon of preferred alkyl aromatics is wherein selected from C ₆-C ₈at least one organic solvent of hydrocarbon is preferred, and wherein heptane, toluene and dimethylbenzene are especially preferred, most preferably heptane, preferably normal heptane.Method steps a3) can just look at applicable any means and carry out by those skilled in the art are known, preferably as counter-current extraction, for example, utilize solvent extraction tower, pulse filling or packed tower, rotating extractor, washing tower, phase separator or be suitable for carrying out with organic solvent extraction water and by the miscellaneous equipment of organic phase and aqueous phase separation.According to the present invention preferably, at least a portion of methacrylic acid in methacrylic aqueous acid will be included in, preferably at least 50 % by weight, preferably at least about 70 % by weight, preferably at least about 80 % by weight, more preferably at least about 90 % by weight are extracted in organic phase.

Therefore according to the step a3 of the inventive method) in obtain two phases: the thick organic phase that comprises methacrylic acid, it is led to the step a4 according to the inventive method), and by above-described amount containing component i. and ii.(water and at least one organic compound) the first water.Can be used as the organic compound that component ii. is included in the first water is any organic compound forming during gas phase oxidation, those that are for example associated mentioned with the thick water obtaining in quench step above, and unreacted C ₄compound and remain in any methacrylic acid in water.Although the first water comprises on a small quantity for method steps a2) the organic solvent of extraction be possible, for example separate with the incomplete of the first water owing to organic phase, this solvent is not considered as component ii..

At the step a4 of the method according to this invention) in, allow step a3) in the thick organic phase experience that comprises methacrylic acid that obtains separate, preferably thermal separation process, with by least a portion of the described methacrylic acid wherein comprising be used as method steps a3) in the organic solvent of extraction agent separate.If use thermal separation, this preferably distills, wherein method steps a3) in for the organic solvent that extracts preferably as the top product of distillation tower or at the upper position of distillation tower, the preferably position in the first half of distillation tower, preferably remove the position in upper 1/3rd, and methacrylic acid or be the richest in the acrylic acid lower position of ratio extraction solvent at distillation tower of base and remove.Bottoms in tower, the ratio that wherein term " bottoms " is also included in distillation tower is collected any phase that collect the low position, one or more positions of one or more methacrylic acid phases, is considered to according to higher-boiling compound phase of the present invention.This bottoms generally comprises the component that boiling point is higher than methacrylic acid, and polymer materials, together with the methacrylic acid of variable quantity, wherein the amount of methacrylic acid can reach maximum about 95 % by weight of gross weight of higher-boiling compound phase or even more.Can also use, for example, fractionation or rectifying tower, thus boiling point is retained in bottoms and can removes more highly purified methacrylic acid in the position higher than this bottoms of this tower higher than the impurity of methacrylic acid.In this case, the situation that the methacrylic acid content of bottoms (higher-boiling compound phase) can be when with simple distillation tower.If there is the boiling point higher than the boiling point of methacrylic acid for the organic solvent extracting, can also remove methacrylic acid phase at the top of tower and/or than the Geng Gao position, one or more position of removing extraction solvent.Being further purified of the methacrylic acid that obtained like this or rich methacrylic acid phase can by means well known by persons skilled in the art, for example, utilize further thermal process, for example distillation or rectifying, or for example undertaken by crystallization by other means.Intermediate steps also can be included in the method according to this invention, at method steps a4) before or during, for example stripping or distillation, to separate low-boiling compound or higher-boiling compound, are filtered to remove solid impurity, crystallization, in washing etc. any or multiple.The number of purifying and other separating step depends on the required purity of contamination level and methacrylic acid final product.If methacrylic acid will in statu quo use, for example use as the monomer for the preparation of methacrylate polymer or comonomer, higher purity may be preferred, this especially depends on final application.If methacrylic acid is by esterified, the lower purity of methacrylic acid can be acceptable, if for example ester final product can be simpler than methacrylic acid, and more effective force or the more words of efficiently purifying.As adopted any thermal process that relates to methacrylic acid or methacrylic ester, separation and/or purifying preferably carry out under one or more stoppers exist.

According in the inventive method preferred embodiment, method steps a4) comprise method steps aa4) higher-boiling compound separates with thick organic phase.

According in this embodiment of the inventive method, higher-boiling compound separates as the bottoms in the distillation of above-mentioned thick organic phase.Term " bottoms " in this article refers in the bottom of distillation, rectifying or separation column or at lower position, the product of preferably extracting out in the position of about bottom 1/3rd.Higher-boiling compound can comprise about 95 % by weight at the most mutually, preferably approximately 60 % by weight-about 95 % by weight, more preferably about 65 % by weight-about 90 % by weight, more preferably about 70 % by weight-about 85 % by weight methacrylic acids, based on the gross weight of higher-boiling compound phase, all the other weight of described higher-boiling compound phase are made up of the boiling point component higher than methacrylic acid (" higher-boiling compound "), for example such as citraconic acid of high boiling point acid, toxilic acid, terephthalic acid, trimellitic acid and analogue, for example p-tolualdehyde of aldehyde and phenyl aldehyde, polymer materials, especially the polymkeric substance of methacrylic acid, and stopper for example, quinhydrones, hydroquinone monomethyl ether, thiodiphenylamine, benzo thiodiphenylamine.

According to the present invention preferably, by method steps aa4) at least a portion of higher-boiling compound phase of separating, preferably at least 50 % by weight, more preferably at least 60 % by weight, more preferably at least 70 % by weight, more more preferably at least 80 % by weight, even more preferably at least 90 % by weight, more preferably at least 95 % by weight, more more preferably whole introducing method step a3) in the first water that obtain or that method steps provides in a).Like this, higher-boiling compound can be processed together with the first water, and can be reclaimed at least a portion that is included in the described methacrylic acid of described higher-boiling compound in mutually.In the time that being merged mutually with higher-boiling compound, the first water may there is a small amount of precipitation, so that words if necessary, if for example sedimentary amount is enough to the one or more further method stepss of disadvantageous effect, or the conveying of interference liquid phase, the words of especially carrying via pipeline,, before liquid phase is directed to further method steps, can carries out optional solid-liquid and separate.According to this embodiment of the inventive method, in the description of the inventive method, quote the first water and be also intended to refer to first water of at least a portion that comprises described higher-boiling compound phase.This processing of higher-boiling compound phase and the first water (they are all thought before this " giving up " mutually and are generally incinerated) also has advantages of such, i.e. their processing and methacrylic acid/methacrylic ester preparation method walk abreast.This is avoided any possible negative impact to methacrylic acid/methacrylic ester preparation method, and this may be by by these, one or two is directly recycled at least in part in methacrylic acid/methacrylic ester preparation method and carries out in mutually.

At least a portion of the methacrylic acid that obtained like this is at method steps a5) in esterification can just look at applicable any mode and carry out by those skilled in the art are known, optionally under existing, stopper carries out, to prevent the polymerization of methacrylic acid and/or methyl methacrylate.Step a5) in carry out esterification in addition restriction especially of means.Esterification can be for example, as US6, and 469,202, JP1249743, EP1254887, US4,748,268, US4,474,981, US4,956,493 or US4,464, described in 229, carry out like that, a part for present disclosure is introduced and be formed as to the disclosure of their esterification that relates to vinylformic acid and methacrylic acid accordingly.Liquid phase esterification is preferred.If esterification utilizes the direct reaction between methacrylic acid and alcohol to carry out, preferably applicable catalyst is passed through in this reaction.Esterifying catalyst is well known by persons skilled in the art and comprises, for example, and heterogeneous or for example solid catalyst of homogeneous catalyst or liquid catalyst.Esterifying catalyst is such as US6 of acidic ion exchange resin preferably, 469,292, describe in JP1249743, EP1254887 or can trade(brand)name

(Rohm and Haas Corp.),

(Dow Corp.) or

those that (Lanxess AG) is purchased, or acid that can catalytic esterification, for example sulfuric acid H ₂sO ₄.

According to the present invention at method steps a5) in preparation methacrylic ester preferably there is formula [CH ₂=C(CH ₃) C(=O) O] _n-R, and can pass through to use formula R(OH) _malcohol methacrylated is formed, wherein

N and m represent 1-10, preferably 1-6, more preferably 1-5, more preferably 1-4, the more preferably integer of 1-3

R is selected from straight or branched, saturated or unsaturated, the ring of aliphatic series or aromatics or the hydrocarbon of straight chain and straight or branched, saturated or unsaturated, the ring of aliphatic series or aromatics or straight chain containing heteroatomic hydrocarbon, for example alkyl, hydroxyalkyl, aminoalkyl group, other residue nitrogenous and/or oxygen, glycol, glycol, triol, bis-phenol, fatty acid residue, the wherein preferred represent methylidene of R, ethyl, propyl group, sec.-propyl, butyl, especially normal-butyl, isobutyl-, hydroxyethyl, preferably 2-hydroxyethyl, and hydroxypropyl, preferably 2-hydroxypropyl or 3-hydroxypropyl, 2-ethylhexyl, isodecyl, cyclohexyl, isobornyl, benzyl, 3, 3, 5-trimethylcyclohexyl, stearyl, dimethylaminoethyl, dimethylaminopropyl, 2-tertiary butyl aminoethyl, ethyl triglycol, tetrahydrofurfuryl, butyldiglycol, methoxy poly (ethylene glycol)-350, methoxy poly (ethylene glycol) 500, methoxy poly (ethylene glycol) 750, methoxy poly (ethylene glycol) 1000, methoxy poly (ethylene glycol) 2000, methoxy poly (ethylene glycol) 5000, allyl group, ethylene glycol, Diethylene Glycol, triethylene glycol, Macrogol 200, poly(oxyethylene glycol) 400, 1, 3-butyleneglycol, 1, 4-butyleneglycol, 1, 6-hexylene glycol, glycerine, two urea alkane, ethoxylation dihydroxyphenyl propane, containing the ethoxylation dihydroxyphenyl propane of 10 ethylene oxide units, TriMethylolPropane(TMP), ethoxylation C ₁₆-C ₁₈fatty alcohol for example contains those of 25 ethylene oxide units, 2-trimethyl ammonium ethyl.

Methacrylic ester can also, by other method well known by persons skilled in the art, for example, by transesterify, be prepared by methyl methacrylate.In another possible preparation of hydroxyester derivative, can be in ring-opening reaction and corresponding ether ring, for example epoxide, especially oxyethane or propylene oxide reaction according to methacrylic acid of the present invention.

Preferred methacrylic ester is alkyl methacrylate, especially methacrylic acid methyl, ethyl, propyl group, sec.-propyl, butyl ester, especially methacrylic acid methyl, normal-butyl, isobutyl-, sec-butyl ester, especially methyl methacrylate, n-BMA, Propenoic acid, 2-methyl, isobutyl ester, hydroxy ester methacrylate derivative, for example hydroxyethyl methylacrylate, preferable methyl HEA, and hydroxypropyl methacrylate, preferable methyl vinylformic acid 2-hydroxypropyl ester or methacrylic acid 3-hydroxypropyl ester, and such as β-dimethyl-aminoethylmethacrylate of other methacrylic ester, 2-Ethylhexyl Methacrylate, isodecyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, methacrylic acid benzyl ester, methacrylic acid 3,3,5-3-methyl cyclohexanol ester, methacrylic acid stearyl, dimethylaminoethyl methacrylate, the amino propyl ester of dimethylaminoethyl acrylate methyl base, methacrylic acid 2-tertiary butyl ammonia ethyl ester, ethyl triglycol methacrylic ester, methacrylic acid tetrahydro furfuryl ester, butyldiglycol methacrylic ester, methoxy poly (ethylene glycol)-350 methacrylic ester, methoxy poly (ethylene glycol) 500 methacrylic esters, methoxy poly (ethylene glycol) 750 methacrylic esters, methoxy poly (ethylene glycol) 1000 methacrylic esters, methoxy poly (ethylene glycol) 2000 methacrylic esters, methoxy poly (ethylene glycol) 5000 methacrylic esters, allyl methacrylate(AMA), ethoxylation (optionally, for example, containing 25mol EO) C ₁₆-C ₁₈the metha crylic ester of fatty alcohol, methyl chloride vinylformic acid 2-trimethyl ammonium ethyl ester, ethylene glycol dimethacrylate, Diethylene Glycol dimethacrylate, TEGDMA, Macrogol 200 dimethacrylate, poly(oxyethylene glycol) 400 dimethacrylate, 1,3 butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, HDDMA, glycerine dimethacrylate, two urea alkane dimethacrylates, ethoxylation bisphenol a dimethacrylate, ethoxylation is (optionally, for example,, containing 10EO) bisphenol a dimethacrylate, trimethylolpropane trimethacrylate, wherein especially preferable methyl methyl acrylate, butyl methacrylate and hydroxy ester methacrylate derivative.

According in aspect one of the inventive method, the separation of method steps in b) preferably includes following methods step:

B1a) with extraction agent extracting process step a3) in the extraction phase of at least a portion that obtain or the first water that method steps provides in a) to form the second water and to comprise at least one component ii.;

B1b) the second water separates with at least part of of described extraction phase;

According to the method steps b1a of the inventive method) in, extract at least a portion of the first water that comprises component i. and ii. with extraction agent, preferably whole, to form extraction phase and the second water.According to the present invention preferably, at least a portion of at least one component ii. is extracted in extraction phase, thus the second water compared with the first water dilution at least one component ii..Extraction preferably at the temperature of envrionment temperature or rising, preferably at about 20 ℃-about 65 ℃, more preferably about 30 ℃-about 60 ℃, more more preferably at the temperature of about 40 ℃-about 55 ℃, carry out.Extract preferably liquid-liquid extraction.Extraction can be just looked at applicable any means by those skilled in the art are known, for example, utilize the known miscellaneous equipment that is suitable for liquid-liquid extraction of just looking at of extraction tower, washing tower, phase separator or those skilled in the art to carry out.Have been found that and be suitable for the method steps b1a according to the inventive method) extraction agent be organic solvent, ionic liquid and organic or inorganic oil.Be suitable for the method steps b1a according to the inventive method) extraction agent (especially organic solvent) preferred feature be to have in following performance at least one, preferably at least two, more preferably at least three, more preferably whole:

I) the average k value of measuring according to method described herein at 25 ℃ in system extraction agent-water for acetic acid is at 0.1-100, preferred 0.2-90, and more preferably 0.3-80, more more preferably 0.3-70, more preferably in the scope of 0.4-60;

Ii) be no more than 2260kJ/kg, be preferably no more than 2000kJ/kg, be preferably no more than 1500kJ/kg, more preferably no more than 1000kJ/kg, then more preferably no more than the evaporation enthalpy of 800kJ/kg;

Iii) 35-140 ℃, preferably 35-125 ℃, more preferably 40-120 ℃, the more more preferably boiling point of 40-110 ℃;

Iv) at 25 ℃, preferably 35 ℃, more preferably 45 ℃, more preferably at the temperature of 50 ℃, be no more than 150g/l again, be preferably no more than 130g/l, more preferably no more than 110g/l, then more preferably no more than 100g/l, even more preferably no more than the solubleness in water of 90g/l.

Except as otherwise noted, under about 50 ℃ and environmental stress, measure above-mentioned performance.Term " k value " refers to partition ratio, i.e. the corresponding organic compound of component ii. of the present invention distribution proportion between organic (extraction) phase and water under equilibrium state.Be greater than 1 k value refer to corresponding organic compound be present in organic (extraction) in mutually than being present in many in water.Although there is the effect I that the extraction agent of the k value that is less than 1 can be used for having reached, but the method according to this invention, higher k value, for example, be greater than 1 k value, therefore be preferred, because they show that organic compound is extracted into extraction phase more completely from the first water.Although the k value up to 100 is possible, have up to about 5,10,20,30,40,50,60,70, the extraction agent of 80 or 90 k value may be also preferred according to the present invention.Lower k value, especially lower than 5 and k value in above-mentioned scope for example, may be also acceptable, if especially extraction agent also has one or more in other preferred properties in favourable scope.If extraction agent is organic solvent, evaporate enthalpy and boiling point preferably low as far as possible in actual limit, liquid preferably especially so that at the extraction agent temperature of carrying out in extraction.Therefore evaporation enthalpy is preferably not less than about 22kJ/mol and boiling point and is preferably greater than 0 ℃, is more preferably not less than the service temperature while extraction.Evaporation enthalpy is not preferably higher than evaporation of water enthalpy (2260kJ/kg or 40.65kJ/mol), to reduce as far as possible according to the step b1b of the inventive method) in the second water and extraction phase after separating by the needed energy input of any residual extractant thermal separation residual in the second water.Evaporation enthalpy is not also preferably higher than at least one evaporation enthalpy in the organic compound of component ii., to reduce as far as possible the needed energy input of one or more organic compound thermal separations of extraction agent and component ii..Especially preferably evaporate enthalpy not higher than at least one the evaporation enthalpy in methacrylic acid, vinylformic acid and acetic acid.For the same reason, with separating for facilitated extraction agent, the boiling point of extraction agent is preferably lower than at least one boiling point in the organic compound of component ii., preferably lower than at least one boiling point in methacrylic acid, vinylformic acid and acetic acid, preferably low as far as possible in preferred scope.If ionic liquid or organic or inorganic oil is as extraction agent, evaporate enthalpy and its boiling point preferably high as far as possible, preferably higher than at least one at least one organic compound of water and component ii..Extraction agent preferably only has low solubility in water, especially under extraction temperature, and preferably substantially or completely water insoluble, and preferably substantially or completely not miscible with it, to can realize separating as far as possible completely of extraction phase and the second water.

According to the step b1b of the inventive method) in, the second water is separated with extraction phase at least in part.According to the step b1a of the inventive method) extraction and method steps b1b) separate and can utilize that those skilled in the art are known just looks at applicable any means, preferably utilize counter-current extraction to carry out, wherein method steps b1a) and b1b) preferably in same equipment, for example utilize extraction tower, Impulse packing or packed tower, rotating extractor, especially use those of centrifugal force separate, washing tower, phase separator or be suitable for the miscellaneous equipment of organic phase or ionic liquid phase and aqueous phase separation to carry out.If with an organic solvent as method steps b1a) in extraction agent, can be by method steps b1b) in the extraction phase that obtains of after separating incinerate.The advantage that this kind of incineration has be substantially organically extraction phase serve as fuel, thereby reduce the demand of buying fuel.For example, if fuel cost or related request, for example carry easily and/or cost be disadvantageous and/or the organic compound of component ii. in one or more marketable value low, especially with they separate and/or the desired overall work of purifying is compared with expense, this option may be preferred.

The second water preferably comprises and is no more than 5.0 % by weight, preferably be no more than 4.5 % by weight, more preferably no more than 4.0 % by weight, again more preferably no more than 3.5 % by weight, more preferably no more than 3.0 % by weight, organic compound beyond the extraction agent even using in the eliminating method step b) more preferably no more than 2.5 % by weight, based on the gross weight of described the second water.The amount of the organic compound in the second water except extraction agent is preferably low as far as possible, preferably 0 % by weight, but 0.5 % by weight, and 0.8 % by weight, the lower limit of 1.0 % by weight or 1.2 % by weight may be acceptable.Any residual extractant (not comprising from method steps b1a) in the total amount of organic compound in the second water), generally speaking, formaldehyde can account for up to about 1.5 % by weight, and based on the gross weight of the second water, all the other are by C ₂or more senior C-chain organic compound, especially C ₂-C ₆or C ₂-C ₄compound forms.The total amount of this kind of organic compound depends on method steps b1a) the extraction step that comprises of extraction or the number of extraction cycle, and the amount of the extraction agent using in this extraction.More the extraction step of high number causes organic compound content lower in the second water, but general also requirement is the longer time and/or multistage extraction, and/or more substantial extraction agent, this may cause the extraction phase of the more volume that then must further process or incinerate.

According in the optional step c) of the inventive method, by least one organic compound at least in part with the second aqueous phase separation, with the 3rd water of at least one organic compound that obtained compared with the second water dilution.Described the 3rd water preferably comprises and is no more than 3 % by weight, preferably be no more than 2.8 % by weight, more preferably no more than 2.5 % by weight, again more preferably no more than 2.2 % by weight, more preferably no more than the eliminating method step b1a of 2.0 % by weight) the middle extraction agent using organic compound in addition, based on the gross weight of described the 3rd water.The amount of the organic compound in the 3rd water is preferably low as far as possible, preferably 0 % by weight.If organic compound is present in the 3rd water, about 1.5 % by weight can be formaldehyde form at the most, rest part eliminating method step b1a) in comprise C beyond the extraction agent that uses ₂or more senior C-chain compound, especially C ₂-C ₆or C ₂-C ₄compound.Therefore the 3rd water preferably comprises and is less than 5000ppm, is preferably less than 4000ppm, is more preferably less than 3000ppm, preferably 0-3000ppm, more preferably 0-2500ppm, more preferably 0-2200ppm, be most preferably not exceeding 2000ppm except C ₁compound (formaldehyde) in addition with eliminating method step b) in organic compound beyond the extraction agent that uses, based on the gross weight of described the 3rd water, wherein 500ppm, or 1000ppm, or 1500ppm, or the lower limit of 1800ppm may be acceptable, this depends on further application and/or the processing of the expectation of the 3rd water.The separation preferably thermal separation of method steps in c), for example distillation or component distillation, preferably under normal pressure.Preferably, method steps c) in, separate to greatest extent the residual method steps b1a that derives from the second water) residual extractant.If method steps b1a) the middle extraction agent using and water formation azeotrope, separate and can comprise component distillation, for example use the component distillation of entrainment agent.In aspect preferred according to one of the step c) of the inventive method, if method steps is middle use by distillation c), especially the separation that utilizes fractional distillation or rectifying to carry out, preferably separate lower boiling component at the top of tower, especially the boiling point component lower than extraction agent, extract extraction agent out at the side outlet of tower, any component ii. or together with extraction agent or at another side outlet of tower, preferably extracts out at the low side outlet of the side outlet than extracting extraction agent out.Then the extraction agent of any separation like this can be recycled to the step b1a according to the inventive method) in extraction, this is corresponding to according to the step of the inventive method h).If identical with any extraction agent of separation in this step mutually in one or more organic compound of separated portion ii., can add mutually this to method steps b1b) in the extraction phase that separates.If different from extraction agent mutually in one or more organic compound of separated portion ii., this not homophase can be directed to according to the step d) of the inventive method or step f).Preferably carry out the step c) according to the inventive method, wherein organic solvent is as the method steps b1a of the inventive method) in extraction agent, if but method steps b1a) in use ionic liquid or oil extraction, it also can carry out.

According to the inventive method this on the one hand in, the separation of method steps in d) preferably includes following methods step:

D1a) at least a portion of described extraction agent separates the extract that comprises at least one component ii. to obtain with described extraction phase;

D1b) optionally, separating of at least a portion of at least one component ii. and described extract.

According to the steps d 1a of the inventive method) in, by method steps b1a) in the extraction agent that uses separate at least in part the extract that comprises at least one component ii. to obtain with extraction phase.If organic solvent is as extraction agent, method steps d1a) in separation preferably utilize thermal separation method to carry out.Applicable thermal separation method is well known by persons skilled in the art, and wherein distillation, fractionation, rectifying and similar approach are preferred according to the present invention, wherein preferably vacuum distilling.One or more separation methods can be included in steps of a method in accordance with the invention d1a) in.In preferred thermal separation method, when as method steps b1a) in the organic solvent of extraction agent while having than the low boiling point of one or more components ii. to be separated, on the top of distillation tower, or at one or more upper positions of separation column or rectifying tower, preferably, in upper part of this tower, remove extraction agent, and in the position with respect to removing extraction agent low one or more positions, or at this tower bottom, the extract of removing one or more components ii. or comprising at least one component ii..Use boiling point than the low organic solvent of at least one component ii. as method steps b1a) in the advantage of extraction agent be some or all of component ii., especially methacrylic acid and vinylformic acid is heat sensitive and along with temperature increase more and more trends towards dimerization, oligomeric or polymerization.Stopper is added in these compounds thermal treatment at elevated temperatures therefore general requirement.If separate more lower boiling extraction agent, if and/or to separate be vacuum distilling, this separation can be carried out under the lesser temps of the boiling point lower than respective components ii., thereby reduces the tendency of polymerization and therefore also reduce the needs to stopper.

If ionic liquid or organic or inorganic oil is the extraction agent in b) as method steps, the separation of method steps in e), preferably by being separated or evaporating, preferably undertaken by the evaporation of one or more volatile constituents.

Method steps d1b) in preferably thermal separation method of separation, preferably distillation, fractionation or rectifying, preferably vacuum distilling wherein separates at least a portion of at least one component ii. from extract.Extract can for example, also comprise extraction agent or other component ii. except at least one component ii. to be separated.If be included in extract more than a kind of component ii., for example two or more component ii., likely at method steps d1b) in only separate a kind of component ii., or separate two or more component ii..Number and the amount of other compound in the extract for the treatment of separating at least one component ii. therefrom can be easily determined and be depended primarily in distillation, fractionation or rectifying by those skilled in the art as the selection of separation means, and the boiling point separately of not intending the component that separates of one or more components ii. to be separated and extract, especially the degree of approach of the boiling point of the boiling point of other component of extract and at least one component ii. to be separated and, if separate more than a kind of component ii., it is the boiling point proximity to one another of component ii. to be separated.Another factor of considering is the required purity of at least one component ii. to be separated.At least one component ii. is further purified may be desirable or or even necessary according to the after separating in the step f) of the inventive method.

In aspect another of the inventive method, the separation of method steps in b) preferably includes following methods step:

B2a) at least a portion of described water is from method steps a3) at least a portion of the first water of obtaining crystallization to form the crystallization water as the second water, and mother liquor, wherein said mother liquor comprises at least one component ii.;

B2b) described crystallization water separates with at least part of of described mother liquor.

According to the method steps b2a of the inventive method) in, allow at least a portion experience crystallization of the first water to obtain crystallization water (wherein the water of this phase exists with crystallized form), and the mother liquor that comprises at least one component ii..Method steps b2a) in crystallization can be by well known by persons skilled in the art for continuously or intermittently, the preferably method of continuous crystallisation, for example dynamic or stationary crystallization or this combination of two kinds, for example melt crystallization, scraping crystallisation by cooling, fractional crystallization, layering crystallization, suspension crystallization, film-falling crystallization and similar approach, or any combination of two or more is carried out in them, the melt crystallization that wherein preferably suspends, preferably with continuous crystallisation process.In aspect preferred according to one of the step b) of the inventive method, crystallization can be undertaken by two stages, wherein in the first stage, crystal formation, for example, on cooling surface, form, and in subordinate phase, allowed these crystal growths and size increase.These two stages can carry out each other in substantially the same region, or each stage can carry out in independent region.As fruit suspension melt crystallization carries out in the method according to the invention, preferably crystallization occurs at least one crystallization and melting circulation.In aspect of suspension melt crystallization according to the present invention is preferred, use at least a portion of at least a portion wash crystallization water of fusion-crystallization water.Applicable method is for example about the purifying of vinylformic acid and/or methacrylic acid and be described in WO02/055469, WO99/14181, WO01/77056, US5,504, in 247, in their disclosure that relates to crystallization, especially WO01/77056 and WO02/055469, disclosed suspension melt crystallization is incorporated herein for reference and is formed as the part of present disclosure.If one or more components ii. in water and the first water forms eutectic mixture, in order to obtain the pure as far as possible water in crystallization (second) water, water preferably only crystallization go out to about eutectoid point.

According to the step b2b of the inventive method) in, the crystallization water as the second water is separated with mother liquor at least in part.Separation can be just looked at applicable any means by those skilled in the art are known, preferably utilize filtration, centrifugation, be separated or other solid-liquid separation means at least one, preferably filtration, centrifugation or be separated carried out, wherein also can comprise the washing of crystal, for example, use at least one washing in mother liquor, fusion-crystallization water and water.This kind of washing-fusion crystallization is for example described in above with respect to method steps b2a with separating) in the reference quoted.According to the step b2b of the inventive method) one preferred aspect in, use is separated, preferably at washing tower, for example being separated in the washing tower of disclosed type in WO01/77056, wherein crystallization phases floats on mother liquor and/or wherein, and/or be collected and/or compacting, for example utilize and in this tower, move up and allow mother liquor to pass and keep the movable plate of crystallization phases on this plate simultaneously, for example be the plate of strainer form, so that crystallization phases can be removed at the top of this washing tower or upper position, and mother liquor passes this plate and removes in the lower position compared with crystallization phases of phase separator.Also possibly, in the lower position fractional crystallization phase of phase separator, this for example depends on the relative density of crystallization water and mother liquor, or for the equipment of crystallization and/or separation.This on the one hand in, can make at least a portion melting of crystallization phases, for example, in interchanger, and guiding gets back to washing tower and is present in the crystallization phases in this washing tower as washings with washing, preferably by counter-current flow.According in another preferred embodiment of the step c) of the inventive method, separate and undertaken by centrifugation.In this embodiment, can make at least a portion melting of crystallization phases, for example, in interchanger, and guiding is got back to centrifugal separation equipment and is present in the crystallization phases in this centrifugal separation equipment as washings with washing.Because mother liquor is poor moisture and comprise the more organic constituent of vast scale compared with the first water, so can be by method steps b2b) in the mother liquor that obtains of after separating incinerate.This kind of incineration has the following advantages, this water-content compared with the first water with reduction substantially organically can serve as mutually fuel, thereby reduce the needs to buying fuel.For example, if fuel cost or related request, for example carry easily and/or cost be disadvantageous and/or the organic compound of component ii. in one or more marketable value low, especially with they separate and/or the desired overall work of purifying is compared with expense, this option may be preferred.

In aspect preferred according to one of the inventive method, step b2a) and b2b) carry out continuously.Crystallisation step b2a) can be being suitable for carrying out the step b2a according to the inventive method) crystalline element in carry out, this crystalline element optionally be suitable for carrying out the step b2b according to the inventive method) separating unit, for example above-mentioned washing unit or centrifugal separation equipment connect.Crystalline element can comprise one or two stage, and it is corresponding to method steps b2a) two possible stages.In crystalline element, or in the first stage of crystalline element, generally cooling the first water so that water are crystallized out at least in part.If crystal forms at least in part on the cooling surface of crystalline element, they can be scraped.If comprise the subordinate phase of crystalline element, then optionally the slurry of gained is directed to described subordinate phase, wherein preferably stir slurry and more polycrystal growth and/or crystalline size increase simultaneously.Then crystal/mother liquor slurry is directed to separating unit from described crystalline element, wherein solid crystal is separated and optionally wash to remove at least in part at least in part impurity.Can make at least a portion melting of the crystal of described optionally washing also at least a portion of described puddle can be directed to further method steps, or process in further method steps, for example at least one biologically pure processing, as process water or be directed to method steps a1) and a2) at least one, as described below, or as washings, the wherein first part of the described fused junction crystalline phase of processing as described below use another part of described fused junction crystalline phase as the washings for washing crystal likely.Also possibly, at least a portion of described crystal is supplied with to crystalline element as crystalline seed.Can also comprise melting step.Melting step can be utilized and can in described crystalline element and washing unit, carry out by inside or the outside equipment of at least one.Crystalline element can be that those skilled in the art are known and seem to be suitable for making any crystalline element of water crystallization from the aqueous solution that comprises organic constituent.Applicable crystalline element, and be combined with washing and/or the crystalline element of melt element is can be from Sulzer Chemtech AG, Switzerland or Niro Process Technology B.V., those that Holland is purchased.Applicable crystalline element, washing unit and melt element, and the example of the crystallization/washing/melt element of combination in the above to method steps b2a) provide in the relevant document of quoting.It is well known by persons skilled in the art being suitable for according to the centrifugal separation equipment of the inventive method.

Method steps b2a) and b2b) can, but must not cause water completely crystallization from the first water so that mother liquor can, or even general really comprise certain water gaging.For example, if one or more in the component ii. of water and the first water form eutectic mixture, situation especially like this.In this case, in order to obtain the pure as far as possible water in crystallization (second) water, water is only preferably that crystallization goes out to about eutectoid point, so that a part for water remains in mother liquor.Therefore the ratio that remains in the water in mother liquor depends on the type and the amount that in the first water, form the respective components ii. of eutectic mixture with water, and water and corresponding eutectoid point this or these components ii..In aspect another of the method according to this invention, the separation of method steps in d) preferably includes at least one in following methods step:

D2a) method steps b2b) at least part of dehydration of mother liquor of separating to obtain the mother liquor of at least part of dehydration;

D2b) at least a portion of at least one component ii. and method steps b2b) in the mother liquor that obtains or with method steps d2a) in the separating of mother liquor of at least part of dehydration of obtaining.

In aspect preferred according to one of the inventive method, will after crystallization, remain at least a portion and method steps d2a of the water in mother liquor) in mother liquor separate.Method steps d2b) in dehydration preferably utilize component distillation, preferably use the component distillation of entrainment agent to carry out.Can consider that those skilled in the art are known and seem to be suitable for method steps b2b) the middle mother liquor separating any entrainment agent of dehydration at least partly.According to the present invention, especially preferred entrainment agent is straight or branched alkane, particularly heptane or hexane, naphthenic hydrocarbon, particularly hexanaphthene, acetic ester, particularly isobutyl acetate or ethyl acetate, aromatic substance, particularly toluene or benzene, or CS ₂, CCl ₄or monobromethane.

Method steps d2b) in preferably thermal separation method of separation, preferably distillation, fractionation or rectifying, wherein separate at least a portion of at least one component ii. with mother liquor or dehydration mother liquor.Described mother liquor or dehydration mother liquor can be for example, also comprise from according to the step a3 of the inventive method except at least one component ii. to be separated) extraction agent, or other component ii..If be included in described mother liquor or dehydration mother liquor more than a kind of component ii., for example two or more component ii., likely at method steps d2b) in only separate a kind of component ii., or separate two or more component ii..Distillation, fractionation or rectifying can easily be made and be depended on many factors by those skilled in the art as the selection of separation means, number and the amount of for example, other compound in mother liquor or the dehydration mother liquor for the treatment of to separate with at least one component ii., and the boiling point separately of not intending the component that separates of one or more components ii. to be separated and mother liquor or dehydration mother liquor, especially mother liquor or the boiling point of other component of dehydration mother liquor and the degree of approach of the boiling point of at least one component ii. to be separated with, if will separate more than a kind of component ii., the boiling point that the has a component ii. to be separated degree of approach to each other.Another factor of considering is the required purity of at least one component ii. to be separated.

According to this one side of the inventive method, described method preferably also comprises following methods step:

E2) melting of described crystallization water is to obtain the fusion-crystallization water as the 3rd water.

The melting of crystallization water is can be by those skilled in the art known and seem that any means that are applicable to carry out.Especially, can allow crystallization water experience it by the temperature of melting, for example, in fusion apparatus or interchanger.Method steps e2) in melting can be equivalent at method steps b2a) and description b2b) in mentioned melting, and/or it can be other melting.Therefore, for example, the first melting may be at method steps b2a) and scope b2b) in carry out, for example, to be provided for the washings of washing crystal.This washings itself is then crystallization on crystal at least in part in the time of its contact crystal preferably.Can make washing like this, the crystal then separating in obtaining the necessary so much washing of required crystal purity-melting circulation again melting so that washings to be provided.Once obtain required purity, can make described crystal according to the step e2 of the inventive method) in melting, and be further directed to biologically pure at least one (as process water) and method steps a1 in processing) and a2) at least one.

Fusion-crystallization water according to this aspect of the invention, or the 3rd water generally there is enough purity and can be directly as process water or as according to the method steps a1 of the inventive method) or a2) in interpolation water.Especially, described crystallization water or fusion-crystallization water preferably comprise and are less than 5000ppm, are preferably less than 4000ppm, be more preferably less than 3000ppm, preferably 1500-2500ppm, more preferably 1800-2200ppm, be most preferably not exceeding the organic compound of 2000ppm, based on the gross weight of corresponding water.Can obtain the impurity of lower amount, for example, be less than about 500ppm, or even be less than 100ppm, 0ppm-100ppm, especially by using the washing-melting circulation in c) of a large amount of steps of a method in accordance with the invention.But the impurity of these lower amounts is general only to be obtained with together with the water of reducing amount.Biologically pure processing can be optionally as process water or as method steps a1) or a2) in interpolation water before carry out.If the water of described fusion-crystallization water will be used for other object or be discharged into environment, may be preferred, but be not always necessary that this kind of use or discharge are biologically pures before.

Preferably allow described the 3rd water experience at least one in following process according to the present invention: be directed at least one biologically pure processing, as process water, and be directed to method steps a1) and a2) at least one.

Term " biologically pure processing " in the scope of the invention is intended to refer to any processing of the purity that improves water, for example, by removing pollutent or impurity, preferably have organic pollutants, utilize one or more biological organisms and/or microorganism or biology or chemical-biological activities material, for example, derived from the material of this type of organism or microorganism.Treat that pollutent and the impurity removed are like this generally the organic compound remaining in the 3rd water.Digestion or decomposition by some or all organic compound are removed.The purity of the increase of water is for example measured as follows: reduce by pollutent and/or impurity, and/or reduce by biochemical oxygen demand (BOD) (BOD) or the chemical oxygen demand (COD) (COD) of water, preferably be reduced to and mean that this waste water can re-use, for example, as industrial technology water, be used further to the method according to this invention, especially method steps a1) or a2) in one or two, maybe can be discharged into the level in environment or water supply chain, this depends on reached purity.Biologically pure processing is well known by persons skilled in the art and passable, for example, is one or more during so-called activated sludge is processed.This kind of processing is conventional and is well known to those skilled in the art.Biologically pure processing can be undertaken by one or more stages, and can be continuous or discrete.

If allow the 3rd water experience at least one biologically pure processing, preferably at least one in aerobic treatment and anaerobic treatment of this processing.In an embodiment of processing with two or more stages, for example, the first anaerobic treatment can then be carried out aerobic treatment below, the first aerobic treatment can then be carried out anaerobic treatment below, maybe can use the sequence of aerobic and/or anaerobic treatment, for example, in order batch reactor.

If the separation according to the method steps of the inventive method in d) is thermal separation, by separated from one another component may be not always unfeasible or be for example in economics or technical reality, if for example two or more components have closely similar boiling point.If experience method steps mother liquor or dehydration mother liquor d) comprises relatively large component, if especially one or more components ii. has similar boiling point with treating at least one the component ii. separating in d) at method steps, becoming more difficult and make that the separation of the just in time a kind of component ii. in method step d) is carried out to meticulous adjusting, may be especially such situation.Then may be more suitable or actual be two or more component ii. to be separated in f) at further method steps, this kind of the adaptation wherein particular separation of respective components ii. being required may be more prone to reach.Therefore, according in aspect one of the inventive method, at least one component ii. that method steps separates in d) can be the mixture of at least two kinds of component ii. and in further method steps

F) at least one component ii. preferably at least in part with this mixture separation.

Separation according to the method steps of the inventive method in f) can comprise one or more separating steps, for example thermal separation, as above to discussing according to other separating step in the inventive method, chromatographic separation, chemical separation, the reaction product that for example can separate with one or more other components ii. more easily with formation by the preferential reaction of a kind of component ii., or reaction product that can be separated from one another more easily with formation by the reaction of two or more component ii., or any other those skilled in the art are known just looks at applicable separation means.

According in the inventive method preferred embodiment, at least one organic compound of component ii., at least one the component ii. preferably separating in f) at method steps is at least in part at least one organic compound that is selected from carboxylic acid, aldehyde and ketone.In the middle of them, preferred at least one component ii. according to the present invention, preferably at least in part method steps f) at least one component ii. of separation, be at least one in acetic acid, vinylformic acid, propionic acid and methacrylic acid.

If method steps d) with f) at least one at least one component ii. of separating be or comprise methacrylic acid,, according in the inventive method preferred embodiment, add at least a portion of this methacrylic acid phase to method steps a2) in obtain thick water and/or method steps a3) in obtain thick organic phase in.For example, if method steps d) with f) in the one or more middle methacrylic acid separating do not there is the required purity of its end-use, this embodiment may be preferred.For example, if the methacrylic acid separating separates lower than other component of methacrylic acid together with one or more boiling points, may be preferred to adding in thick water.For example, if the component except methacrylic acid has the boiling point higher than methacrylic acid, may be preferred to adding in thick organic phase, because being that this kind of higher compound can be at method steps a4) in separation.Although methacrylic acid and other component, especially the relative proportion of other component ii. also can play a role, but the character of other component at least one the component ii. separating at least one in e), f) with j) of method steps determine to add mutually to which this separate at least one in e), f) with j) at method steps aspect the phase of methacrylic acid, there is larger weight.For example, if method steps d) with f) at least one in the methacrylic acid that separates purer, for example comprise, be no more than about 5 % by weight, preferably be no more than about 4 % by weight, be preferably no more than about 3 % by weight, be preferably no more than about 2 % by weight, the impurity of preferably approximately 1 % by weight-about 2 % by weight or other component ii., introduce this methacrylic acid optional method steps a4) purification step may be preferred.

In aspect another of the inventive method, allow method steps d) with f) at least one at least a portion of at least one component ii. of separating, or method steps a3) in the first water of obtaining at least a portion experience method steps g) esterification to obtain the ester phase that comprises at least one ester.

If at least one component ii. is carboxylic acid accordingly, this step may be preferred.The details of esterif iotacation step with above to according to the method steps a5 of the inventive method) describe those are identical.Replace or except obtaining corresponding at least one component ii. itself extraly, method steps d) with f) at least one in the esterification of at least one component ii. of separating may be preferred, this for example depends on the obtainable purity of separated respective components ii., market or other application of respective components ii. compared with its ester.For example, if the first water only comprises the impurity of small proportion and/or does not intend the component ii. separating, for example the gross weight meter based on described the first water is less than about 6 % by weight, preferably be less than about 5 % by weight, preferably be less than about 4 % by weight, be more preferably less than the impurity of about 3 % by weight and/or do not intend the total impurities of the component ii. separating, based on the gross weight of described the first water, especially for example, itself compare and may be more prone to the impurity that separates with the ester of respective components ii. with component ii., be included in method steps a3) in the esterification of at least one component ii. in the first water of obtaining may be preferred.

Be included according to ester of the present invention especially preferred ester group in mutually in C ₁-C ₄carboxylic acid and C ₁-C ₄alcohol, wherein based on C ₂-C ₄the ester of carboxylic acid is preferred.Except together with method steps a5) especially preferred ester also has methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, methyl acrylate, ethyl propenoate, vinylformic acid n-propyl, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, methyl propionate, ethyl propionate, n propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, sec-butyl propionate mentioned methacrylic ester, preferably acetic ester and acrylate in them.

According to the present invention likely, ester comprises at least two kinds of esters mutually.If method steps d) with f) at least one at least one the component ii. or the method steps a3 that separate) at least a portion of the first water of obtaining comprise at least two kinds and can react the component ii. that form ester, especially at least two kinds of carboxylic acids, situation may be like this.If can react described at least two kinds of component ii. of formation ester is especially difficult to separate, for example, by heat or other means, for example, when their performance for example boiling point, solubleness and/or volatility in given solvent are very approaching, and their ester is time can be less difficultly separated from one another, this embodiment may be preferred.

The method according to this invention may further include following methods step

H) at least one ester at least part of separation mutually from described ester;

J) optionally, the h) purifying of middle at least one ester separating of method steps.

Generally speaking, except at least one ester, ester can also comprise solvent mutually, and for example water or be suitable at least one organic solvent of esterification, or their mixture, and unreacted component ii., also have one or more other esters possibly.The separation of method steps in h) is can be by those skilled in the art known and seem to be suitable for any separation means that corresponding esters and ester are separated.The example of applicable separation means is, for example, thermal separation, for example distillation, fractionation or rectifying, the separation means of the different solubilities compared with other component based at least one ester and ester phase, solid-liquid separation means is for example filtered etc.If desired or wish, also can carry out the purifying of at least one ester that method steps separates in h).Means of purification depends on ester, wherein for example, and by hot means, by chromatogram means, by washing or can considering by the purifying of crystallization.

According in the inventive method preferred embodiment, at least a portion of at least one ester obtaining at least one in g), h) and j) of method steps can be used as method steps b1a) in extraction agent.

According in the inventive method embodiment, the method is further comprising the steps of

Aa1) division of methyl tertiary butyl ether (MTBE) is to obtain at least one C ₄compound and methyl alcohol,

Wherein said at least one C ₄at least a portion of compound is as raw material supplying method steps a1) and 1) at least one gaseous oxidation.MTBE is widely used as the raw material of iso-butylene and the division of MTBE is well known in the art.The division of MTBE can be undertaken by any suitable means well known by persons skilled in the art.Applicable catalyzer and reaction conditions are for example described in, in Publication about Document: EP1149814, WO04/018393, WO04/052809; Ullmann ' s Encyclopedia of Industrial Chemistry, the 5th edition, A4 volume, the 488th page; V.Fattore, M.Massi Mauri, G.Oriani, G.Paret, Hydrocarbon Processing, in August, 1981,101-106 page; Ullmann ' s Encyclopedia of Industrial Chemistry, the 5th edition, A16 volume, 543-550 page; A.Chauvel, G.Lefebvre, " Petrochemical Processes, Technical and Economic Characteristics ", the 1st volume,

technip, Paris, 1989, the 213 pages and continued page; US5,336,841, US4,570,026 and the reference wherein quoted.The disclosure of these reference is incorporated herein for reference and is formed as the part of the disclosure of invention.

Two kinds of primary products of MTBE division are C ₄compound iso-butylene and methyl alcohol.Another kind of C ₄the compound trimethyl carbinol also may be included in dissociative reaction product mutually in.In iso-butylene and the trimethyl carbinol, any or both can be used as raw material supplying method steps a1), to be configured for total C of raw material of this method steps ₄compounds content or the supplementary other C that derives from other source ₄content.In the middle of one or more, separation and/or purification step are at division and such at least one obtained C of MTBE ₄compound is to method steps a1) in gaseous oxidation supply between be also possible, for example, with as far as possible by described at least one C ₄compound and methyl alcohol are separated from one another and remove any by product that may adversely affect gaseous oxidation from described fission process.Separation and/or purification can be well known by persons skilled in the art and look like applicable any means.Applicable purification and separation method for example, are described in EP1149814A1, WO04/018393A1 and WO04/052809A1.After separating methanol, then can optionally described C will be comprised ₄compound iso-butylene is as the division phase purifying of major constituent and offer method steps a1 as raw material).Applicable method of purification be well known by persons skilled in the art and preferably include distillation, extraction, absorption, absorption, chromatography or washing at least one, preferably distill and extract at least one, preferably at least one distillation and at least one extraction.The C from this step by unreacted MTBE at least in part ₄in Compound Phase, separate.Can optionally the MTBE purifying of separation be also recycled to dissociative reaction at least in part.

According in the inventive method preferred embodiment, by method steps aa1) in the methyl alcohol supply method step g) that obtains.In aspect another of the inventive method, can be by method steps aa1) in the methyl alcohol supply method step a5 that obtains).Can, optionally by this methyl alcohol purifying, preferably utilize for example distillation of hot purifying, fractionation or rectifying, crystallization, extraction, tower or washing, more preferably distillation at least one times.The example of methyl alcohol purifying is described in EP1254887.

The invention still further relates in methacrylic acid and methacrylic ester the Preparation equipment of at least one, at least comprise the assembly that the following guiding of fluid is each other communicated with:

A1) gaseous oxidation unit,

A2) quenching unit,

A3) the first extraction cells,

A4) the first separating unit,

A5) optionally, the first esterification unit,

B) the second separating unit,

C) optionally, the 3rd separating unit,

D) optionally, the 4th separating unit,

Wherein the first separating unit is the thermal separation unit in its underpart 1/3rd with at least one outlet at bottom, and described at least one outlet at bottom is communicated with at least one inlet fluid guiding of the second separating unit.

Term " fluid guiding is communicated with " is interpreted as and refers to that unit can be that in liquid, gas, steam, supercutical fluid or any other fluid, the fluid of at least one can direct at least one other unit from a unit through connecting satisfied at this.This can be for example by via pipe or pipeline (for example, by the material of resistance to reaction reagent and leading condition, for example stainless steel or glass or any other applicable material well known by persons skilled in the art are made) direct connection reach, or utilize and be arranged in tank car between each unit or groove or reservoir and indirectly reach.If pilot gas and its should keep gaseous state, the device of pilot gas preferably maintains than at the high temperature of the dew point of this gas.If guiding liquid, the device of guiding this liquid preferably maintain than the component existing in this liquid and/or this liquid solidify and/or temperature that set point is high under.This can be by means of heat insulation the device of the corresponding gas of guiding or liquid and/or heating are reached.The condition that all reactors, tower and other apparatus assembly are preferably experienced by resistance to reaction reagent and they, for example especially material manufacture of temperature and pressure condition.

Gaseous oxidation unit A1) preferably include the reactor that at least one is suitable for carrying out gas-phase reaction, especially pressure reactor, preferably at least one multitubular reactor, for example be formed as pipe and shell mould reactor, and/or at least one panel-shaped reactor and/or at least one fluidized-bed reactor, wherein multitubular reactor is preferred.Especially preferred is at least one multitubular reactor, and wherein oxide catalyst is arranged at least one pipe, and preferably wherein this pipe is filled or applied with oxide catalyst, preferably fills.According to the present invention, preferred oxide catalyst is mentioned those relevant to the inventive method above.Reactor material should be patience and preferred inertia to the reaction reagent of inside reactor and leading condition.Applicable reactor can be for example from MAN DWE GmbH, Deggendorfer Werft, Germany or from IHI Corporation, Japan is purchased and is formed as a part for general knowledge as well known to those skilled in the art.

In two stage gas phase oxidations, gaseous oxidation unit can comprise at least two reaction zones, and each reaction zone comprises oxide catalyst.Described at least two reaction zones can be at least two reaction zones in single reaction vessel, or at least two reactors.Oxide catalyst in the first reaction zone is preferably by least one C ₄compound, preferably iso-butylene and/or Oxidation of t-Butanol become the oxide catalyst of Methylacrylaldehyde, and oxide catalyst in second reaction zone is preferably suitable for Methylacrylaldehyde to be oxidized to methacrylic acid.Applicable catalyzer is mentioned relatively with the method according to this invention in the above.

In aspect of present device is preferred, oxygenant, preferably oxygen, preferably at least one feedway at least one source of air, and at least one feedway of water and/or steam, is communicated with gaseous oxidation unit fluid.If gaseous oxidation unit at least comprises the first oxidation zone and another oxidation zone, this equipment can comprise at least one feedway of at least one oxidizer source and at least one feedway of water and/or steam for each oxidation zone.Equipment may further include the feedway of thinner, described thinner is nitrogen, argon gas and/or carbonic acid gas for example, preferred nitrogen or carbonic acid gas, for example, from catalytic combustion unit (CCU) or hot fuel element (TCU), the preferably CCU in downstream or the carbonated recycle gas of TCU in the device in accordance with the invention.Corresponding feedway should be made up of for example stainless steel of material or the glass of resistance to reaction reagent and leading condition.In preferred design, by C described in oxygen, thinner and water supply ₄stream, then enters corresponding reactor, so that preformed mixture enters reactor.

According to the step a1 of the inventive method) preferably in gaseous oxidation unit, carry out.

According in present device preferred embodiment, quenching unit A2) be wherein by the condensation of gaseous oxidation phase and/or absorption and form the absorptive unit of liquid phase.Preferably make to be present in methacrylic acid in the oxidation mutually of leaving catalytic reaction zone at quenching unit A2) in condensation and form solution, the preferably aqueous solution as main oxidation products containing methacrylic acid.Also can be at absorptive unit A2) in unreacted Methylacrylaldehyde is separated and if necessary, guiding is got back to gaseous oxidation district for further reaction.It is well known by persons skilled in the art being suitable for according to the quenching unit of present device.According to the step a2 of the inventive method) preferably at quenching unit A2) in carry out.

According in present device preferred embodiment, quenching unit A2) be connected to the first extraction cells A3 below).By quenching unit A2) in form be directed to the first extraction cells A3 containing methacrylic aqueous acid), organic solvent is wherein provided, methacrylic acid is preferably extracted in this solvent substantially.Organic solvent is preferably substantially immiscible with water, thus be formed to small part dilution methacrylic acid water and containing the organic phase of methacrylic acid.About the details method steps a3 in the above of preferred organic solvent) description in provide.Method steps a3) preferably in the first extraction cells, carry out.Those skilled in the art are known and seem that any extraction cells being applicable to for this kind of extraction of methacrylic acid can consider as the first extraction cells A3).

Equipment according to the present invention is included in the first extraction cells A3) the first separating unit A4 in downstream).If equipment according to the present invention is for the preparation of methyl methacrylate, the first separating unit A4) preferably at the first esterification unit A5) upstream, preferably at the first extraction cells A3) and the first esterification unit A5) between and be communicated with their fluids.The first separating unit A4) be preferably suitable for methacrylic acid to separate, preferably purifying, in particular for by methacrylic acid with for the first extraction cells A3) extraction agent separate, preferably also allow methacrylic acid and the first extraction cells A3 leaving according to present device) thick organic phase in other component of existing separate, this thick organic phase is corresponding to according to the method steps a3 of the inventive method) thick organic phase.The first separating unit A4) thermal separation unit preferably, preferably include distillation tower, separation column, rectifying tower and those skilled in the art known and seem to be suitable for the method steps a3 of the inventive method) any other heat separation device separating at least one.The first separating unit A4) comprise that more than one separation phase is possible.The first separating unit A4) preferably include at least one outlet at bottom, this outlet at bottom can be in the bottom of the first separating unit or the outlet in its underpart 1/3rd.The first separating unit A4) this layout preferably allow higher-boiling compound to separate with thick organic phase, this is corresponding to according to the method steps aa4 of the inventive method).Described at least one outlet at bottom preferably with the second separating unit B) the guiding of at least one inlet fluid be communicated with.This fluid guiding connection can utilize the direct conduit between at least one outlet at bottom of described the first separating unit and at least one entrance of described the second separating unit to reach.Can also be by least one intermediate equipment and/or assembly R) be arranged at least one outlet at bottom and the second separating unit B of the first separating unit) at least one entrance between, for example at least one other separating device, for example at least one other thermal separation equipment and/or at least one solid/liquid separation means, and/or at least one mixing equipment and/or at least one reservoir, for example, for can be by the first separating unit A4) in the higher-boiling compound that separates introduce mutually the first water, preferably for described higher-boiling compound phase and the first water being combined, optionally by the higher-boiling compound phase of the component of described higher-boiling compound phase and/or described combination and the first aqueous phase separation.Those skilled in the art are known and seem that any equipment and the assembly that are suitable for described object can be included in according in equipment of the present invention.

For purifying the first separating unit A4) the first optional purification unit of the methacrylic acid of separation also can be arranged in the first separating unit A4) downstream.The first optional purification unit can be, for example, hot purification unit, such as distillation tower, separation column, rectifying tower etc., crystalline element, or those skilled in the art are known and seem to be suitable for any miscellaneous equipment of purifying methacrylic acid.

Equipment according to the present invention may further include the one or more extra assembly between any or all mentioned unit or assembly, for example, by heat or the stripper plant of height and/or low boiling component separation, solid/liquid separation apparatus, for example at least one strainer and/or whizzer, and/or cooling and/or heating unit.In preferred design, for example, for the distillation tower of low-boiler and optionally in addition filter arrangement in downstream, quenching unit and extraction cells upstream.In aspect another of two stage gas phase oxidation unit is preferred, quenching cell layout is between this two stage.

Unreacted Methylacrylaldehyde can be in quenching unit, the first extraction cells, the first separating unit, the first purification unit or any above-mentioned other equipment component any in separate, and gaseous oxidation unit is got back in guiding so that further reaction.

The first esterification unit A5) can be arranged in the first separating unit A4) or the downstream of optional the first purification unit.To the first esterification unit A5) not in addition restriction and can be to be suitable for esterification to be formed methacrylic ester by methacrylic acid especially, any unit of preferable methyl methyl acrylate.It is preferably suitable for liquid phase esterification.The first esterification unit A5) preferably include esterifying catalyst, it can be heterogeneous or for example solid catalyst of homogeneous catalyst or liquid catalyst, and such as US6 of acidic ion exchange resin preferably, 469,292, describe in JP1249743, EP1254887 those or with trade(brand)name

(Rohm and Haas Corp.),

(Dow Corp.) or

The second purification unit can be arranged in the first esterification unit A5) downstream so that by wherein produce methacrylic ester purifying.The second optional purification unit can be, for example, and hot purification unit, such as distillation tower, separation column, rectifying tower etc., crystalline element, or those skilled in the art are known and to seem to be suitable for purifying methacrylic acid be ester, especially any miscellaneous equipment of methyl methacrylate.

Also comprise the second separating unit B according to equipment of the present invention).The second separating unit B) by the first extraction cells A3) in the first water of obtaining at least a portion of the water that comprises separate with at least a portion of especially above-mentioned at least one the component ii. of at least one organic compound, to obtain the second water and organic phase.According to the method steps of the inventive method b) preferably at the second separating unit B) in carry out.

According in present device preferred embodiment, the second separating unit B) comprise the second extraction cells B1).The second extraction cells B1) at least a portion of being used for extracting the first water with extraction agent to be to form the second water and extraction phase, and be preferably used for the second water as far as possible at utmost to separate in technology limit with described extraction phase.Therefore, according at least method steps b1a of the inventive method) and preferred method steps b1a) and b1b) preferably at the second extraction cells B1) in, most preferably undertaken by continuous mode.The second extraction cells B1) to preferably include at least one extraction tower, washing tower, phase separator or those skilled in the art known and seem to be suitable for liquid-liquid extraction, preferably also be suitable for organic phase or ionic liquid phase and aqueous phase separation, more preferably be suitable for by the miscellaneous equipment of continuation method extraction and fractionation, for example at least one extraction tower, at least one Impulse packing and/or packed tower, at least one rotating extractor, especially at least one uses rotating extractor, at least one washing tower and/or at least one phase separator that centrifugal force separates.The second extraction cells B1) preferably can be under envrionment temperature, and in the temperature except envrionment temperature, the temperature especially raising, especially above with method steps b1a) and b1b) tolerance and operation at mentioned temperature relatively.

According in another preferred embodiment of present device, the second separating unit comprises

B2a) crystalline element, and

B2b) optionally, Crystallization Separation unit.

At crystalline element B2a) in, generally cooling first aqueous solution obtaining in the first extraction cells so that water are crystallized out at least in part.Then can carry the slurry of gained, optionally via stopping unit T1) grow for crystal, as above-mentioned and method steps b2a) and b2b) relevant as described in, be transported to crystal separation unit B 2b), for example washing tower or whizzer, wherein solid crystal is separated with mother liquor at least in part, preferably washing is to remove to greatest extent at least in part residual impurity.At least one fusion apparatus also can be included in the second separating unit B2) in, and can be at crystalline element B2a) and Crystallization Separation unit B 2b) at least one inside or outside, preferably at least with Crystallization Separation unit B 2b) be communicated with fluid and/or solid guiding.Preferably at least one melt element, make described optionally washing crystal at least a portion melting and allow at least a portion of described puddle be passed to next apparatus assembly or the washings as the crystal in Crystallization Separation unit, or both of these case.Also possibly, utilize one or more conduits using at least a portion of described crystal from crystal separation unit B 2b) supply crystalline element B2a) and/or supply with stop unit T1) as crystalline seed.

Those skilled in the art known and seem to be suitable for above-mentioned purpose any crystalline element, stop unit and crystal separation unit and can, for equipment according to the present invention, wherein preferably allow continuous crystallisation and the corresponding units separating.Crystalline element can be that those skilled in the art are known and seem to be suitable for making any crystalline element of water crystallization from the aqueous solution that comprises organic constituent, wherein preferred suspension crystallization unit, is even more preferably equipped with scraper so that the cooling surface that may form from crystal scrapes away the suspension crystallization unit of crystal at least in part thereon.Stop unit (if providing) preferably in channel form, be preferably equipped with whipping appts, and the entrance that is equipped with at least one and crystalline element fluid and/or solid to guide to be communicated with guides with Crystallization Separation unit fluid and/or solid the outlet being communicated with at least one.Crystalline element, is optionally preferably suitable for carrying out the step b2a according to the inventive method together with stopping unit).Crystal separation unit is preferably suitable for carrying out the step b2b according to the inventive method), and preferably washing tower or centrifugal separation equipment.Applicable crystalline element, and the crystalline element that is combined with washing and/or melt element is, for example, as works " Melt Crystallisation Technology ", author G.F.Arkenbout, Technomic Publishing Co.Inc., Lancaster Basel(1995), 265-288 page, Chem.Ing.Techn.(72) (10/2000), the suspension crystallization unit with the downstream washing of crystal in waterpower or machine washing tower described in 1231-1233.Generally speaking, there is any washing melting washing tower of forced conveyance, for example Chem.Ing.Techn.57(1985) No.2,91-102 page and Chem.Ing.Techn.63(1991), No.9, described in 881-891 page and WO99/6348 those.The example of applicable washing melting tower is described in EP97405, US4735781, WO00/24491, EP920894, EP398437, EP373720, EP193226, EP191194, WO98/27240, EP305316, US4787985, and can be for example from TNO Institute in Apeldoorn, Holland, from Niro Process Technology B.V., Hertogenbosch, NL, or from Sulzer Chemtech AG, Switzerland, TNO or Niro Process Technology B.V., Holland is purchased.Applicable crystalline element, washing unit and melt element, and other example of the crystallization/washing/melt element of combination also in the above with method steps b2a) provide in the document quoted relatively.Suitable for being well known by persons skilled in the art according to the centrifugal separation equipment of the crystal separation unit in present device.

At least one incinerator or fuel element can be included in according in equipment of the present invention, and the mother liquor for example obtaining for extraction phase that the second extraction cells is obtained or from crystalline element and/or crystal separation unit incinerates.

Equipment according to the present invention may further include the 3rd separating unit C).The 3rd separating unit C) be preferably especially included in wherein equipment according to the present invention and comprise in the embodiment of extraction cells as the second separating unit, but also can be included in wherein equipment according to the present invention comprises in the embodiment of crystalline element as the second separating unit.The 3rd separating unit C) be preferably used for method steps b1a) middle any residual extractant and the second aqueous phase separation using.The 3rd separating unit C) can be other extraction cells, but preferably thermal separation unit, such as distillation tower, separation column, rectifying tower etc., wherein those skilled in the art's any device known and that seem to be suitable for this kind of separation can be considered with in the device in accordance with the invention.

Equipment according to the present invention can further include the 4th separating unit D).The second separating unit B therein) comprise extraction cells B1a) embodiment in, the 4th separating unit D) preferably include at least one thermal separation equipment D1a) comprise according to the extract of at least one component ii. of the present invention at least a portion of described extraction agent being separated with extraction phase to obtain, this is corresponding to method steps d1a).Can also comprise the thermal separation equipment D1b that at least one is other) to will separate from described extract according at least a portion of at least one assembly ii. of the present invention, this is corresponding to method steps d1b).Those skilled in the art are known and seem to be suitable for carrying out method steps d1a) with d1b) the thermal separation equipment separating such as can consider, for equipment according to the present invention, at least one in distillation, fractionation or rectifying tower etc.

The second separating unit comprises in the embodiment of crystalline element and crystal separation unit therein, the 4th separating unit D) preferably include dewatering unit D2a) and other separating unit D2b) at least one.Dewatering unit D2a) be preferably suitable for carrying out the method steps d2a of the inventive method).Those skilled in the art are known and seem that the dewatering unit of at least part of dehydration that is suitable for the mother liquor separating in crystalline element and/or crystal separation unit can consider for equipment according to the present invention.According to the present invention, preferred dewatering unit is, for example, is filled with the dewatering agent not reacting with at least one component ii., the tower of for example molecular sieve, and distill unit, be especially suitable for the distillation unit of component distillation.Other separating unit D2b) be preferably suitable for carrying out the steps d 2b according to the inventive method), preferably thermal separation unit.Those skilled in the art are known and seem to be suitable for carrying out method steps d1a) with d1b) the thermal separation equipment separating such as can consider, for equipment according to the present invention, at least one in distillation, fractionation or rectifying tower etc.

Other separating unit also can be included in according in equipment of the present invention.An example of preferred other separating unit is to be suitable at least one component ii. from the mixture that comprises at least two kinds of component ii. according to the present invention, for example, according to the separating unit of the mixture separation obtaining in the step d) of the inventive method.This kind of preferably thermal separation unit of other separating unit, preferably includes at least one distillation tower, separation column, rectifying tower etc.

According to equipment of the present invention preferably at the 4th separating unit D) and at least one other separating unit at least one, and the first extraction cells A3) and/or the first separating unit A4) between comprise at least one conduit so that by methacrylic acid and containing methacrylic acid mutually at least one from the 4th separating unit D) and at least one other separating unit at least one guiding get back to the first extraction cells A3) and the first separating unit A4) at least one.

Optionally comprise at least one second esterification unit G according to equipment of the present invention) for by least one component ii. esterification, preferably at the second separating unit B), the 3rd separating unit C) and the 4th separating unit D) at least one downstream.The method steps of the inventive method is g) preferably at the second esterification unit G) in carry out.Relate to the second esterification unit G) details with above regard to the first esterification unit A5) mentioned those are identical.

Can also comprise at least one ester separating unit H according to equipment of the present invention) to one or more esters are separated each other at least partly, especially by least one ester and described at least one second esterification unit G) in obtain ester separate at least partly mutually, this method steps corresponding to the inventive method is h).Those skilled in the art are known and seem that any equipment that is suitable for ester separation can be used as ester separating unit H).The thermal separation equipment of the type of having mentioned, and crystallizer, extraction equipment, device for phase saparation are preferably as according to the ester separating unit in present device.

The purification unit J that at least one is other) also can be provided in according in equipment of the present invention, for by the second esterification unit G) obtain or at least one ester separating unit H) in one or more ester purifying of separating.According to the method steps of the inventive method j) preferably at least one other purification unit J) in carry out.The details of this other purification unit corresponding to those of the relevant mentioned purification unit of the first esterification unit.

If can also be included in the second extraction cells B1 comprising according to equipment of the present invention), and the second esterification unit G), ester separating unit H) and for the other purification unit J of purification of at least one ester) between at least one ester conduit.Described at least one ester conduit is used at least one ester from the second esterification unit G), ester separating unit H) and for the other purification unit J of purification of at least one ester) at least one direct into the second extraction cells B1a), wherein said at least one ester can optionally be used as extraction agent.

In aspect preferred according to one of present device, described equipment is also included in gaseous oxidation unit A1) MTBE of upstream division unit AA1).The division unit dividing for MTBE and applicable catalyzer are well known in the art and are formed as a part for general knowledge as well known to those skilled in the art, for example, be described in Ullmann ' s Encyclopedia of Industrial Chemistry, the 5th edition, A4 volume, the 488th page; V.Fattore, M.Massi Mauri, G.Oriani, G.Paret, Hydrocarbon Processing, in August, 1981,101-106 page; Ullmann ' s Encyclopedia of Industrial Chemistry, the 5th edition, A16 volume, 543-550 page; A.Chauvel, G.Lefebvre, " Petrochemical Processes, Technical and Economic Characteristics ", the 1st volume, technip, Paris, 1989, the 213 pages and continued page; US5,336,841, US4,570,026 and the reference wherein quoted in.

Iso-butylene separating unit S1) preferred arrangements is at MTBE division unit AA1) and gaseous oxidation unit A1) between and guide and be communicated with its each fluid.Iso-butylene separating unit S1) be used for iso-butylene phase, preferably also have methyl alcohol phase, separate with the ejecta of the second catalytic reaction zone, this ejecta comprises iso-butylene and methyl alcohol as major constituent.Iso-butylene separating unit S1) can be at least one in extractor, crystallizer, tower, distillation plant, rectifying device, film, pervaporation equipment, phase separator and washing plant.Iso-butylene separating unit S1) preferably include the outlet of iso-butylene phase and the outlet of methyl alcohol phase.The outlet of described iso-butylene phase preferably with gaseous oxidation unit A1) be connected, optionally connect via temporary location for example purification unit, interchanger and/or pressurizer.The outlet of described methyl alcohol phase is preferably connected with at least one in the first esterification unit and the second esterification unit, optionally via middle methyl alcohol purification unit.Can comprise that those skilled in the art are known and seem that any equipment that is suitable for purification of methanol is as methyl alcohol purification unit.The example of applicable purification unit preferably includes at least one distillation plant, crystallizer, extractor, tower or washing plant, more preferably at least one distillation plant.The example of methyl alcohol purification unit is described in EP1254887.

The invention still further relates to the method according to this invention, wherein the method is carried out in the device in accordance with the invention.

Illustrate in more detail the present invention by accompanying drawing and non-limiting example.

Accompanying drawing explanation

Fig. 1 schematically shows preferred embodiment of the process according to the invention with schema form.

It is the embodiment of an apparatus according to the present invention of extraction cells that Fig. 2 schematically shows wherein the second separating unit B.

It is the embodiment of an apparatus according to the present invention of crystalline element that Fig. 3 schematically shows wherein the second separating unit B.

According to the embodiment of Fig. 2, by C ₄compound imports in gaseous oxidation unit A1, and wherein it is oxidized to methacrylic acid in one or two stage catalytic vapor phase oxidations.C ₄the entrance that compound, oxygen, steam and inert dilution gas enter gaseous oxidation unit A1 does not illustrate.C ₄it is not shown that compound can divide unit AA1(from MTBE), via iso-butylene separating unit, S1(is not shown) provide.Via pipeline 1, the gaseous state methacrylic acid obtaining in gaseous oxidation unit A1 is directed to quenching unit A2 mutually, wherein it is cooled and absorbs in water or water and form the water containing methacrylic acid.The entrance that quench liquid enters quenching unit A2 does not show.Via pipeline 2, moisture methacrylic acid is directed to the first extraction cells A3 mutually, its extraction is formed organic phase and water (according to first water of the inventive method) by the organic solvent that is wherein used as extraction agent.These two separate in the first extraction cells A3.

Via pipeline 3, described organic phase is directed to the first separating unit A4 from the first extraction cells A3, wherein its distillation is separated to methacrylic acid and extraction agent and higher-boiling compound phase.Can extraction agent be recycled to the first extraction cells A3 via pipeline 6.Can collect methacrylic acid purifying in one or more purification unit (not shown) in downstream optionally via pipeline 5, or can it be directed to the first esterification unit A5 via pipeline 4, optionally via purifying (not shown).In the first esterification unit A5, can by methacrylated, for example, use methyl alcohol, for example not shown at separating unit S1() in divide with MTBE the methyl alcohol being separated, to form methyl methacrylate.Can also be with other alcohol as above by methacrylic acid esterification in the first esterification unit A5.Collect the ester that produces in the first esterification unit A5 and it can be optionally not shown at polymerized unit A6(via pipeline 7) in polymerization, in the middle of optionally having and/or the purifying in downstream.The higher-boiling compound of collecting in the first separating unit A4 is directed to the second separating unit B mutually, and optionally via merge cells R guiding, wherein it can merge with the water separating in the first extraction cells A3 if desired.

The water separating in the first extraction cells A3 is directed to the direct conduit that the second separating unit B(does not show), optionally, via pipeline 24 and merge cells R guiding, wherein it can merge mutually with higher-boiling compound if desired.Also can omit merge cells R, water and higher-boiling compound directly merge each other in the second separating unit B.

The organic solvent that is used as the second extraction agent extracts the water that merges and higher-boiling compound with formation water (corresponding to second water of the inventive method) and organic phase in the second separating unit B.Via pipeline 9, this water is directed to the 3rd separating unit C, wherein can separates at least in part from the residual extractant of the second extraction step and also optionally be recycled to the second separating unit B via pipeline 25.Can by residual water (corresponding to the 3rd water of the inventive method) recirculation, for example, be recycled to gaseous oxidation unit A1(and not show conduit), as process water, be directed to biologically pure unit (not shown) or discharge via pipeline 20.Can the organic phase separating in the second separating unit B be directed to the 4th separating unit D via pipeline 10, wherein can separating at least one component ii..Can collect via pipeline 11 at least a portion the purifying (not shown) optionally of at least one the component ii. separating in the 4th separating unit D.If the mixture of separated portion ii. in the 4th separating unit D, can be directed to other separating unit by this mixture so that by (not shown) separated from one another component ii..If separate methacrylic acid or the phase containing methacrylic acid in the 4th separating unit D, can be via pipeline 15 by this methacrylic acid or being directed to mutually the first extraction cells A3 or being directed to the first separating unit A4 via pipeline 16 containing methacrylic acid.Also at least a portion of at least one the component ii. separating in the 4th separating unit D can be directed to the second esterification unit G via pipeline 14.Can be by any in the organic phase and the water that separate in the second separating unit B, or the water separating in the 3rd separating unit C is directed to the second esterification unit G.In the second esterification unit G, with alcohol by least one component ii. esterification to form corresponding ester.If alcohol is methyl alcohol, this methyl alcohol can for example, import from MTBE splitter AA1 via the separating unit S1 optionally with intermediate purification (not shown).If the ester obtaining in the second esterification unit G comprises mutually more than a kind of ester, can be in ester separating unit H separating at least one ester.Can be not shown at the ester purification unit J(in downstream) in by least one ester purifying.At least one ester of one or more middle acquisitions in the second esterification unit G, ester separating unit H and ester purification unit J can be directed to the second separating unit B so that as extraction agent.

It is another embodiment of the equipment of crystalline element that Fig. 3 shows wherein the second separating unit B according to the present invention.In this embodiment, relate to below identical in the details of apparatus assembly A1 to A6, R, G, H, J, AA1 and S1 and the embodiment of Fig. 2 and only different aspect is described in.In the embodiment of Fig. 2 example, generally in crystalline element B2a, mutually cooling with higher-boiling compound the water of merging so that water are crystallized out at least in part.If crystal forms at least in part on the cooling surface of crystalline element B2a, they can be scraped.Then optionally the slurry of gained is directed to stop unit T1(not shown), wherein preferably stir described slurry, simultaneously more polycrystal growth and/or crystalline size increase.Then from crystalline element B2a and/or stop unit T1, the slurry of crystal and mother liquor is directed to crystal separation unit B 2b via pipeline 9, wherein solid crystal is separated at least in part and optionally wash to remove at least in part impurity with mother liquor.A part for crystal can be back to crystalline element B2a and/or to stopping unit T1 to serve as crystal seed (not showing conduit) from crystal separation unit B 2b guiding.

Can make described optionally washing crystal at least a portion melting and can be by least a portion recirculation of puddle, for example be recycled to gaseous oxidation unit A1(and do not show conduit), as process water, be used as washings so that the crystal in washing crystal separating unit B2a is directed to biologically pure unit (not shown) or discharges via pipeline 20.Can the mother liquor separating in crystal separation unit B 2b be directed to the 4th separating unit D via pipeline 10, wherein can separating at least one component ii..The 4th separating unit D can comprise dewatering unit D2a and/or thermal separation cells D 2b.If the mixture of separated portion ii. in the 4th separating unit D, can be directed to another separating unit by this mixture so that by (not shown) separated from one another component ii..If separate methacrylic acid or the phase containing methacrylic acid in the 4th separating unit D, can be via pipeline 15 by this methacrylic acid or being directed to mutually the first extraction cells A3 or being directed to the first separating unit A4 via pipeline 16 containing methacrylic acid.Can collect via pipeline 11 at least a portion the purifying in other purification unit (not shown) optionally of at least one the component ii. separating in the 4th separating unit D.Also at least a portion of at least one the component ii. separating in the 4th separating unit D can be directed to the second esterification unit G via pipeline 14.The mother liquor separating in Crystallization Separation unit B 2b can be directed to the second esterification unit G.

Test method

The measurement of partition ratio (k value)

The organic solvent of the water that comprises predetermined amount acetic acid and same volume (extraction agent) is merged.At 50 ℃, shake and/or stir these two phase 15-30 minutes to guarantee to reach the equilibrium distribution of acetic acid in water and organic phase.Then allow this mixture to separate at 50 ℃ and get back to organic phase and water mutually separated from one another by these two.Measure the amount of the acetic acid existing in the organic phase separating by gas-chromatography (GC) or high pressure liquid chromatography (HPLC).

·HPLC: Agilent1200

Pump: quaternary gradient pump

O eluent: acetonitrile KH ₂pO ₄(0.02mol/L) pH2

Gradient 3min 0% 100%

· 15min 50% 50%

· 30min 70% 30%

O flow: 1.0ml/min

O stand-by time: 30min

Operation (post) time: 5min after o

O control pressure: 190 bar, maximum 250 bar

Self-actuated sampler: self-actuated sampler

O volume injected: 20 μ L

Post stove: comprise post switching controls

O temperature: 30 ℃

O post: Agilent SB-Aq

Dimensions length 150mm, d _i4.6mm, 3.5 μ m materials

Detector MWD or DAD

O UV 210nm, 241nm, 254nm, 265nm (DAD is preferred)

· GC: Perkin Elmer Autosystem

Self-actuated sampler: Perkin Elmer

O cleaning solvent THF

O volume injected 1.0 μ L

Syringe:

O shunts splitting ratio 100

200 ℃ of o temperature program(me)s

Constant flow pressure 12.0

Post stove:

O post J & W Scientific DB225

O dimensions length 30m, d _i0.25mm, 0.25 μ m material

O temperature program(me)

Speed temperature (℃) stand-by time (min)

Initial 40 5.0

15 180 4.0

O working time: 18.3min

Detector FID

260 ℃ of o set(ting)values

Embodiment

Embodiment 1:

Embodiment 1 has described a part for method as shown in Figure 4.By the 82.1 % by weight MAA that contain of the upper generation of the first separating unit A4, 14.3 % by weight are various and part is unknown higher-boiling compound (dimerization and oligomeric MAA, toxilic acid, terephthalic acid, citraconic acid, polymkeric substance etc.) and the higher-boiling compound of 3.6 % by weight stoppers (being mainly quinhydrones) with among merge cells R, merge by the higher-boiling compound of 1:80 and the ratio of the first water from first water that contains 0.6 % by weight MAA and 5.0 % by weight higher-boiling compounds of the first extraction cells A3 segregation.Measurement of concetration in the merging mutually of gained is 1.6 % by weight MAA and 5.1 % by weight higher-boiling compounds.In the second separating unit B, extract the phase of described merging with normal hexane.In organic phase, produce 4.9 % by weight MAA, with respect to 3.9 % by weight MAA in the contrast situation in the time the first water not being merged mutually with described higher-boiling compound.

Claims

1. the method for preparing in methacrylic acid and methacrylic ester at least one, comprises following methods step:

A3) at least a portion of described methacrylic acid is extracted into organic solvent from the described thick water that comprises methacrylic acid, to obtain the thick organic phase that comprises methacrylic acid, and the first water, wherein said the first water comprises following component:

Wherein the weight amount sum of i. and ii. is 100 % by weight;

B) be included in step a3) in the separating of at least a portion of water in the first water of obtaining and at least a portion of at least one component ii., to obtain the second water and organic phase, wherein said organic phase comprises at least one component ii., and wherein said the second water compared with the first water dilution at least one component ii.;

C) optionally, at least a portion of at least one organic compound and b) separating of middle the second water obtaining of method steps, to obtain the 3rd water;

2. pack processing, containing the method for the water of at least one organic compound, comprises following methods step:

A) provide the first water that comprises following component

Wherein the weight amount sum of i. and ii. is 100 % by weight;

B) be included in separating of at least a portion of water in the first water that method steps provides in a) and at least a portion of at least one component ii., to obtain the second water and organic phase, wherein said organic phase comprises at least one component ii., and wherein said the second water compared with the first water dilution at least one component ii.;

3. according to the method for claim 1 or claim 2, wherein method steps a4) comprise following methods step:

Aa4) separating of higher-boiling compound and thick organic phase.

4. according to the method for claim 3, wherein by least a portion introducing method step a3 of described higher-boiling compound phase) in the first water that obtain or that method steps provides in a).

5. according to the method for any one in the claims, wherein the separation of method steps in b) comprises following methods step:

B1a) with extraction agent extracting process step a3) at least a portion that obtain or the first water that method steps provides in a), with the extraction phase that forms the second water and comprise at least one component ii.;

B1b) the second water separates with at least part of of described extraction phase.

6. according to the method for claim 5, wherein the separation of method steps in d) comprises following methods step:

D1a) separating of at least a portion of described extraction agent and described extraction phase, to obtain the extract that comprises at least one component ii.;

7. according to the method for claim 5 or claim 6, wherein said the 3rd water comprises and is no more than 3.0 % by weight, preferably be no more than 2.8 % by weight, more preferably no more than 2.5 % by weight, again more preferably no more than 2.2 % by weight, more preferably no more than the eliminating method step b1a of 2.0 % by weight) the middle extraction agent using organic compound in addition, based on the gross weight of described the 3rd water.

8. according to the method for any one in claim 1-4, wherein the separation of method steps in b) comprises following methods step:

B2a) at least a portion of described water is from method steps a3) crystallization at least a portion of the first water of obtaining, to form crystallization water as the second water, with mother liquor, wherein said mother liquor comprises at least one component ii.;

9. method according to Claim 8, wherein the separation of method steps in d) comprises at least one in following methods step:

D2a) method steps b2b) at least part of dehydration of mother liquor of separating, to obtain the mother liquor of at least part of dehydration;

10. according to Claim 8 or the method for claim 9, further comprise following methods step:

E2) melting of described crystallization water is to obtain fusion-crystallization water as the 3rd water.

11. according to the method for any one in claim 7-10, wherein said the 3rd water or crystallization water comprise and are no more than 5000ppm, preferably be no more than 4000ppm, more preferably no more than 3000ppm, preferably 1500-2500ppm, more preferably 1800-2200ppm, is most preferably not exceeding the organic compound of 2000ppm, based on the gross weight of described the 3rd water.

12. according to the method for any one in the claims, wherein allows described the 3rd water experience at least one in following process: be directed at least one biologically pure processing, as process water, and be directed to method steps a1) and a2) at least one.

13. according to the method for any one in the claims, and at least one component ii. that wherein method steps separates in d) is the mixture of at least two kinds of component ii., and wherein in following other method steps

F) at least one component ii. separates at least in part from this mixture.

14. according to the method for any one in the claims, and wherein at least one organic compound of component ii. is at least one organic compound that is selected from carboxylic acid, aldehyde and ketone.

15. according to the method for any one in the claims, and wherein said at least one component ii. is or comprises at least one in acetic acid, vinylformic acid, propionic acid and methacrylic acid.

16. according to the method for any one in the claims, wherein method steps d) with f) at least one in described at least one component ii. of separating be or comprise methacrylic acid, and add at least a portion of this methacrylic acid to method steps a2) in the thick water or the method steps a3 that obtain) in the thick organic phase that obtains.

17. according to the method for any one in the claims, wherein allow method steps d) with f) at least one in described at least one the component ii. or the method steps a3 that separate) at least a portion experience following methods step of the first water of obtaining:

G) esterification is to obtain the ester phase that comprises at least one ester.

18. according to the method for claim 17, and wherein said ester comprises at least two kinds of esters mutually.

19. according to the method for claim 17 or claim 18, comprises in addition following methods step:

H) at least one ester separates with at least part of of described ester phase;

J) optionally, the h) purifying of middle described at least one ester separating of method steps.

20. according to the method for any one in claim 17-19, and at least a portion of described at least one ester wherein obtaining in step g), at least one h) and j) is as method steps b1a) in extraction agent.

21. according to the method for any one in claim 17-20, and wherein said at least one ester group is in C ₁-C ₄carboxylic acid and C ₁-C ₄alcohol.

22. according to the method for any one in the claims, comprises the following steps in addition:

Aa1) division of methyl tertiary butyl ether is to obtain at least one C ₄compound and methyl alcohol,

Wherein said at least one C ₄at least a portion of compound is as raw material supplying method steps a1) at least one gaseous oxidation.

23. according to the method for claim 22, wherein by method steps aa1) the middle methyl alcohol supply method step g) obtaining.

24. for the preparation of at least one equipment in methacrylic acid and methacrylic ester, at least comprises the assembly that the following guiding of fluid is each other communicated with:

Gaseous oxidation unit (A1),

Quenching unit (A2),

The first extraction cells (A3),

The first separating unit (A4),

Optionally, the first esterification unit (A4),

The second separating unit (B),

Optionally, the 3rd separating unit (C),

Optionally, the 4th separating unit (D),

Wherein said the first separating unit is thermal separation unit, comprises at least one outlet at bottom in its underpart 1/3rd, and described at least one outlet at bottom is communicated with at least one inlet fluid guiding of the second separating unit (B).