CN102908956A - Esterification reactor and production method of dimethyl maleate - Google Patents
Esterification reactor and production method of dimethyl maleate Download PDFInfo
- Publication number
- CN102908956A CN102908956A CN2011102175257A CN201110217525A CN102908956A CN 102908956 A CN102908956 A CN 102908956A CN 2011102175257 A CN2011102175257 A CN 2011102175257A CN 201110217525 A CN201110217525 A CN 201110217525A CN 102908956 A CN102908956 A CN 102908956A
- Authority
- CN
- China
- Prior art keywords
- reactor
- air entraining
- entraining pipe
- notch
- column plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The invention relates to an esterification reactor and a production method of dimethyl maleate. The esterification reactor is suitable for esterification reactions of carboxylic acids and alcohols. The reactor is composed of a plurality of tower plates; each tower plate is provided with a downtake pipe and an ascension pipe, wherein the ascension pipe is connected with a gill type gas distributor; each tower plate reserves a certain liquid level liquid, wherein the liquid contains a solid catalyst; and the liquid phase is a component containing a carboxylic acid, flows downward from an esterification tower plate to the following tower plate in the reactor, and reacts with rising alcohol steam countercurrent. The esterification reactor has the advantages of adequate contact of three phases (gas, liquid and solid), high reaction efficiency, high volume utilization rate of the reactor, and the like; and is suitable for various esterification reaction processes.
Description
Technical field
The present invention relates to the production method of a kind of reactor and dimethyl maleate, particularly be applicable to the reactor that carboxylic acids and alcohols material carry out esterification.
Background technology
Esterification is the process that is generated ester by monoacid, binary acid or polyacid (also can be acid anhydrides under the specified conditions) and alcohol or aldehydes matter reaction, and esterification is generally reversible balanced reaction.These alcohol, aldehydes matter can be monohydric alcohol, dihydroxylic alcohols or polyalcohol.As follows take monoesters as the example course of reaction:
R
1Can be the organic group of a hydrogen atom or unit price, R
2It is the organic group of unit price.When reactant was acid anhydrides, reaction was divided into for two steps:
R
3Divalent organic group, R
4It is the unit price organic group.
The most frequently used catalyst is sulfuric acid and such as the sulfur-bearing organic acid of benzene sulfonic acid etc.But these catalyst are homogeneous catalyst, although catalytic effect is very good, must just can obtain ester phase product through after the neutralization reaction, and neutralization procedure is commonly used highly basic reagent (such as sodium hydroxide solution), and this process has following shortcoming:
1, esterification is the reaction that balances each other, and unreacted carboxylic acid can be participated in neutralization reaction, and it is very difficult to separate unreacted carboxylic acid from the carboxylic acid salt solution, so neutralization procedure can cause obvious significant loss in this technique;
2, have the ester of part to be dissolved in the alkali lye in the neutralization reaction process, have the part ester to be dissolved in the alkali lye with sodium-salt form, the loss amount of ester depends on the solubility of ester in alkali lye;
3, the organic carboxylate that produces in the water-washing process can aggravate problem of environmental pollution;
4, when containing LCFA in the product, can form highly basic soap with the strong base solution reaction, hard soap is surfactant, meets water and forms stable emulsion, is difficult to carry out water-oil separating.Adopting homogeneous catalyst to carry out continuous esterification has a lot of shortcomings, usually adopts intermittent reaction, and product quality is not high.
5, adopting another shortcoming of homogeneous catalyst is that ester is mixed with sulfur component in mutually, and sulfur component will have a strong impact on the subsequent process operation.
For addressing this problem, development in laboratory is a kind of take the technique of acid-exchange resin as the Catalyst Production dimethyl maleate.At EP-A-0255399 this technology is set forth.Describe according to patent, liquid phase is monomethyl maleate, with pure steam continuous flow upstream reaction preparation dimethyl maleate in the zone of esterification catalyst is housed, solid catalyst is deposited in the guard on the column plate in the trickle bed mode in the tower, and liquid phase flows downward and with the more and more higher pure steam of concentration the esterification zone counter current contacting reaction of catalyst is being housed.Another kind of reactor types is one group of continuous stirred tank that links to each other.Liquid phase flows to next reactor by a reactor, and pure steam flows to previous reactor by next reactor simultaneously.This mode of operation complicated operation, and reaction efficiency is lower.
The described technical scheme of EP-A-0255399 and WO-A-88/00937 is comparatively complicated.A plurality of column plates with guard are arranged in the reaction tower, and ion-exchange resin catalyst is contained in the guard.This compound reactor system need to carry out continued operation to mixer, is difficult to implement.WO-A-90/08127 discloses a kind of esterifier and technique, uses the plate column plate-type reactor, but need in every layer of column plate reaction compartment of reactor vertical plate washer be set, to increase the contact effect of reaction mass.This mode effect is limited, can not make bed temperature and hydrodynamics even, is difficult to effectively improve the service efficiency of reactor.
Summary of the invention
For the deficiencies in the prior art, the invention provides the production method of a kind of esterifier and dimethyl maleate, esterifier of the present invention is by arranging the vapor distributor of suitable structure, make the acidic catalyst of solid particle easily load and be easy to suspension, the reactor utilization rate is high, and reaction efficiency is high.The present invention also provides a kind of production method of dimethyl maleate, uses ion-exchange resin catalyst, and under reactiveness, catalyst is suspended in the reaction mass.
Esterifier of the present invention, comprise tower-like reactor shell, at least one deck column plate is installed in the housing, solid esterification catalyst bulk storage is on column plate, downspout and the riser of column plate passed in setting, liquid level on downspout upper end open and the column plate is suitable, the downspout lower openings stretches into below the adjacent lower floor column plate liquid level, riser is communicated with gas distributor in the position on column plate top, gas distributor is fish gill formula gas distributor, gas distributor is made of air entraining pipe and the fish gill formula distribution of gas mouth that is distributed on the air entraining pipe, air entraining pipe is connected on the riser, the notch of inclination is set on air entraining pipe the latter half cylinder, notch outside cover film sleeve pipe, the edge on the long limit of the corresponding air entraining pipe notch of membrane casing has scarfing.
In the esterifier of the present invention, air entraining pipe can comprise main air entraining pipe and an air entraining pipe, and main air entraining pipe is generally Straight, and main air entraining pipe is communicated with riser, and an air entraining pipe can be spirally coiled, also can be Straight, and an air entraining pipe is communicated with on main air entraining pipe.The quantity of main air entraining pipe and an air entraining pipe can be according to the make out the scale of reactor.
In the esterifier of the present invention, the distance of air entraining pipe and column plate is generally 100mm ~ 500mm, preferred 100mm ~ 200mm.Inclined notch on the air entraining pipe is generally bar shaped, and the width of notch is preferably 2～20mm generally greater than 1.5mm, and the length of notch is generally 5%～30% of air entraining pipe girth.The angle of inclination of notch (notch and horizontal angle) is generally 15～75 degree, is preferably 30～50 degree.Notch evenly distributes on air entraining pipe, or to make diverse location gas by the hydrodynamics design be that design discharge is determined the distribution mode that suits.
In the esterifier of the present invention, the scarfing of the membrane casing that air entraining pipe notch outside covers is arranged on the edge on the long limit of air entraining pipe notch, scarfing can be arranged on the edge on any long limit in two long limits of air entraining pipe notch, the scarfing position can the service notch adjustment direction of ejection air-flow, be that scarfing has guide effect to air-flow when opening under airflow function, the direction of guide effect is air entraining pipe notch edges one side that scarfing is set.Air current flow direction as required arranges.The position of scarfing is generally the long limit one lateral edges extension 1mm ~ 7mm of air entraining pipe notch, preferred extension 2mm ~ 5mm, and decide according to hydrodynamics distribution, thin-film material intensity and thin-film material elasticity concrete scarfing position.The length of scarfing is generally 70%～150% of air entraining pipe notch length, is preferably 80%～120%.Can being made by corrosion resistant alloy foil sheet of the membrane casing that air entraining pipe notch outside covers; Can also make for the non-metal anti-corrosion material; The composite film material that can also be alloy and non-metal anti-corrosion material is made.The non-metal anti-corrosion material has the preferably material of corrosion resistance and elastic strength such as: anti-corrosive rubber, polytetrafluoroethylene, natural or synthetic resin, polyester film etc.
This scarfing need not slice off any position only on desired location membrane casing is cut open, and the state class that this scarfing is opened in operating process is like the fish gill, so the gas distributor among the present invention is called fish gill formula gas distributor.
In the reactor of the present invention, in order to ensure distribution of gas and the effective deposition of washing away to avoid catalyst to the tower tray bottom of formation, gas passes through the gas speed of scarfing generally greater than 10m/s, but the resistance drop that causes in order to limit gas distributor, the present invention limits this gas flow rate less than 100m/s, generally gets 20m/s-50m/s.When tower pressure drop hour, scarfing diminishes, and produces fine and closely woven bubble; When the tower pressure drop was large, it is large that scarfing becomes, and gas speed improves, and produces equally fine and closely woven bubble.Because the scarfing of gas distributor has certain inclination angle, gas is ejection downwards at a slant, and its shear stress plays a role in promoting to W-response liquid, has avoided the existence of reactor blind area.Be conducive to like this distribution of gas even, and produce enough little bubble, improve the uniformity of reaction system, improve reaction efficiency, improve the reactor volume utilization rate.
When esterifier of the present invention used, column plate quantity can require specifically to determine according to character and the rear product quality of reaction of reaction mass, is generally 3 ~ 50.Keep certain liquid on each column plate, filling solid esterification catalyst at least part of column plate.
The production method of dimethyl maleate of the present invention, use the above-mentioned esterifier of the present invention, take monomethyl maleate and methyl alcohol as raw material, take storng-acid cation exchange resin as catalyst, monomethyl maleate is introduced from reactor head with liquid form, methyl alcohol is introduced from reactor bottom with the gas phase form, and 10～40 sieve plates are set in the reactor, obtains dimethyl maleate after the reaction and draws reactor from reactor bottom.
The concrete reaction condition of dimethyl maleate production is: the mol ratio 1:1.5 of maleic acid mono alkyl ester/alkylol～1:5, the liquid phase feeding of maleic acid mono alkyl ester is 0.2h to the cumulative volume air speed of resin catalyst
-1～2.0h
-1, reaction temperature is 90 ℃～160 ℃, reactor bottom inlet steam pressure limit is that 0.1MPa is to 3MPa.
Esterifier of the present invention uses solia particle or beaded catalyst, has avoided the great number of issues that uses homogeneous catalyst to bring.Reactor simultaneously of the present invention uses the gas distributor of suitable structure, has improved reaction efficiency, has improved reactor and has held the title utilization rate, has improved the disposal ability of whole reaction system.
Description of drawings
Fig. 1 is a kind of tower plate structure schematic diagram that comprises downspout and riser of esterifier of the present invention.
Fig. 2 is esterifier gas distributor structural representation of the present invention.
Fig. 3 is esterifier gas distributor air entraining pipe cross section knot schematic diagram of the present invention.
The specific embodiment
Esterifier of the present invention in use, two kinds of chargings are a kind of to be introduced with liquid form, another kind ofly introduces with the gas phase form, in reaction, gas-phase feed will react the water that generates and be taken the purity of raising reaction conversion ratio and final products out of.Requirement is located under the pressure at first block of column plate (top column plate), the boiling point of esterifier outlet mixed vapour, and the boiling point that perhaps exports in the mixed vapour light component will be starkly lower than the boiling point of any one component under this condition in the restructuring minute product.In general, boiling point differs at least 15 ℃ under same pressure, is preferably more than 25 ℃, to realize realizing distillation in reaction.
In this area, the reaction of suitable employing reactor of the present invention mainly includes the course of reaction that corresponding esters is produced in machine acid or organic acid anhydride and alcohol reaction.For the production process of organic acid dibasic acid esters, general monoesters behind single-esterification is with alcohol is as charging accordingly, and the catalytic distillation that adopts reactor of the present invention to carry out double esterification reacts.
Single-esterification refers to that the unary fatty acid here refers to comprise the aliphatic acid of 6～26 carbon, or two or more mixture wherein with unary fatty acid and alkanol or acid anhydrides and reaction of alkanol generation unary fatty acid ester among the present invention.Preferably the alkanol of 1～10 carbon number makes Arrcostab.
Reactor of the present invention can be used for the production of monobasic acid ester.Monoacid comprises similar aliphatic acid and two kinds or the two or more mixtures such as aliphatic acid such as capric acid, dodecylic acid, tetradecanoic acid, linoleic acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachic acid, isostearic acid.Aliphatic acid can react fatty acid methyl ester admixture processed with methyl alcohol, and fatty acid methyl ester repeated hydrogenation alkanol processed is such as C
8To C
20Alkanol (usually also being the washing agent alcohols), can separate making detergent to alkanol.
Reactor of the present invention also is applicable to the production of binary of fatty acids ester.Made by alkanol and dicarboxylic acids or its acid anhydrides or dicarboxylic acids and acid anhydride mixture reaction thereof.The dicarboxylic esters of producing such as oxalate diester, maleic acid diester, succinic diester, fumaric acid diester, penta diester, heptan, diester, azelaoyl also comprised oxolane, comprised that all are from C
1To C
10The alkyl acid ester.Any contain dicarboxylic acids or its acid anhydrides (if existence) or dicarboxylic acids and composition thereof can be as the raw material of producing this dicarboxylic esters.
C
7To C
20The preparation of monobasic alkyl aromatic ester and composition thereof also be applicable to the present invention, such as benzoic acid and the acid of 1-naphthols etc.The present invention is equally applicable to C
8To C
20The aromatic carboxylic acid esters of aromatic acid, acid anhydride and composition thereof preparation binary.The present invention is equally applicable to polyacid and prepares polynary ester.Polyacid has: citric acid, pyromellitic acid dianhydride etc.The present invention is equally applicable to prepare binary alcohol esters and polyol ester, dihydroxylic alcohols such as ethylene glycol, propane diols etc., polyalcohol such as glycerine, sorbierite, sweet mellow wine, xylitol etc.
Esterification condition temperature in the reactor is normal temperature to 200 ℃, such as temperature range at 80 ℃ to 180 ℃, preferred 100 ℃ to 135 ℃.Require the Thermodynamically stable of esterification catalyst, dividing relevant temperature and the kinetics of pressure with the steam group of esterifier bottom steam entrance, selecting this operating temperature under the condition.Reactor bottom inlet steam pressure limit be 0.1MPa to 3MPa, be preferably 0.2MPa between the 2.5MPar.Reactor air speed scope is 0.1h
-1To 10h
-1, 0.2 h especially
-1To 5h
-1
The liquid phase of alcohol, acid or its compositions of mixtures and the ester product of circulation and solvent or diluent are by the top charging of reactor.Can also carry out first without the pre-esterification reactor under the catalytic condition the pure and mild acid that enters before the reactor under given conditions, also can be the pre-esterification reactor that has under the catalytic condition.For example acid anhydrides such as maleic anhydride and phthalic anhydride and fatty alcohol such as methyl alcohol, ethanol, tert-butyl alcohol reaction, obtain under the condition that relatively relaxes monoesters as: 60 ℃, 0.5MPa without the condition of catalysis under reaction equation as follows:
R
5Alkyl such as methyl, ethyl, butyl.This monoesters also is monoacid.Further reaction is as follows:
The result is that product is the mixture that contains monoesters, dibasic acid esters, water and alkanol.If need to add again excessive alkanol, make monoesters in reactor, further react the generating portion diester.
In the present invention cat head discharging is mixed vapour.The mixed vapour that light component in reactor (normally alkoxide component) forms carries out stripping so that it gets back to reactor to carboxylate product and other composition (normally carboxylic acid composition).Overhead vapours separates its component with condensing mode, and the water that esterification generates and light component (normally alcohol) recycle after the light component drying.Water vapour on the esterification column plate of the bottom is fewer, and the esterification conversion ratio is more near 100%, and the carboxylic acid content at the bottom of the tower in the product of reactor bottom is lower.Yet the impact of the pure steam that the esterification balance is often supplied (being light component steam), as the alkylol steam of sufficient drying will be provided in the reactor, when the pure steam of drying reduces, just need to change the operation of liquid phase feeding, make it reach product requirement with the quality that improves the ester product.This will cause the reaction between the alcohol, the reaction depend between the alcohol and water influence each other and pure moisture from effect.The water in the pure steam will be less than 5mol% in the reactor when using methanol steam, most preferably less than 1mol%.
Contain many column plates in the reactor.Although sometimes only have the reaction of two or three block of column plate, usually have 5 to 20 or more esterification column plate in the reactor.The time of staying of designing on every block of esterification column plate is 1 minute to 120 minutes, particularly 5 to 60 minutes.Can design according to the control index.
Solid catalyst is for containing-SO
3The granular ion exchange resin of H/-COOH.Proper resin has " DZH large porous strong acid resin ", " NKC-9 ", " D001 ", " ZG C 132 ", " CT450 " etc., can specifically select according to the type of esterification, specifically can select various suitable commercial products.
On the different column plate different catalyst is housed in the reactor, even with column plate on filling concentration also different.Particulate on every block of column plate or the loadings corresponding requirements catalyst weight of beaded catalyst account for the liquid weight ratio and are at least 0.2%; for example the resin concentration scope is calculated as 2%～20% with dried resin; preferred 5%～10%, the catalyst that filling is enough under the suitable time of staying and relevant operating condition is to reach molecular balance or near molecular balance.To such an extent as to catalyst that on the other hand can not sc makes the ascending air of column plate bottom be difficult to it is stirred into suspension.
The catalyst granules diameter should be enough large so that its easily retained by the cover on the column plate or similar devices.Yet the particle of catalyst is larger just more be hard to keep suspension state and catalyst surface area is reduced, so catalyst granules again can not be too large, proper catalyst granules diameter range is 0.1mm to 5mm, is preferably 0.4mm to 0.8mm.
Provide one or more washing column plate to hold back product and solvent and/or the reagent in the reactor at the esterification column plate.
Note avoiding the part to have solid esterification catalyst precipitation to get off, because may cause like this side reaction to occur, perhaps focus appears in the part as far as possible.Can guarantee to make catalyst granules remain on suspended state by the stirring action of ascending air to liquid by the distributor of column plate reasonable in design.In order to reach this purpose, at least part of esterification column plate or more (preferably whole column plates) will be set as the inclined-plane to the turbulent region by the distributor manufacturing.The inclination angle is preferentially selected more than or equal to the dwell angle in the liquid phase of solid catalyst on column plate.The purpose that adopts this angle is that catalyst all when operating and liquid all move up and do not have the blind area, because the blind area can cause some side reactions.
At the preferred device that prevents the liquid suck-back of installing of the esterification column plate that has ascending air to pass through (one or more are preferably whole), prevent that the device of liquid suck-back generally is installed in the riser, generally adopt the backward stop valve arrangement.Protective cover is installed on the dependency structure, and protective cover generally is installed in the upper opening of downspout, and the mesh diameter of protective cover is generally less than the particle diameter that uses catalyst, effectively to prevent esterification catalyst spilling to lower channel from the esterification column plate.Prevented fully that by such method solid catalyst runs off to next piece column plate from a column plate.
Esterifier of the present invention uses solia particle or beaded catalyst, has avoided the great number of issues that uses homogeneous catalyst to bring.Reactor simultaneously of the present invention uses the coiled gas distributor, has improved reaction efficiency, has improved reactor and has held the title utilization rate, has improved the disposal ability of whole reaction system.
As shown in Figure 1, the column plate 4 of a level is set in the middle of reactor wall 2, a downward downspout 5 and a riser that makes progress 6 are arranged on the column plate, form first stage reactor 3.
An axial conical section 7 is arranged on the column plate 4, the riser 6 that rises for gas in the middle of the cone, ring section 8 is connected on the contiguous reactor wall 2 obliquely.Can stop liquid on the column plate, liquid level 9 depends on the height of downspout 5 on column plate 4.All be equipped with on every block of column plate and contain sulfonic ion exchange resin such as DZH large porous strong acid resin particle 10.Ion-exchange particulate on the column plate is stirred into suspension in liquid.In order to prevent that the logical liquid of ion-exchange particulate from letting out together, installed guard 12 in the downspout upper end from downspout 5.The angle of cone 7 and ring section 8 requires more than or equal to DZH large porous strong acid resin or other solid esterification catalyst granules the dwell angle in the liquid on esterification column plate 4.
Be connected to cross master air entraining pipe around the cone riser, the air-flow that rises in the riser 6 enters main air entraining pipe, arrives an annular air entraining pipe again, and through fish gill formula gas distributor, rising steam is separated into bubble 11 after entering reaction mass.
16 is the downspout that upper block column plate comes among Fig. 1.The liquid level 17 of downspout 16.Height H adds what fricative pressure determined by the liquid level of lastblock column plate and the pressure of distributor generation thereof on the column plate liquid level.
Monobasic, binary or polybasic carboxylic acid or its mixture contact with the pure steam counter-flow of rising with liquid form when reactor operation.Every block of column plate all is the esterification district that esterification catalyst is housed separately, all carries out esterification and remove simultaneously the water that esterification generates under the effect of catalyst.The pure steam vaporization that the water that esterification generates in reactor is risen and the top that is entrained to reactor.In liquid phase stream during through reactor, when liquid phase is fallen next piece column plate from a column plate the liquid phase concentration liquid of acid more and more lower, on column plate, contact with the pure steam of drying more and more again.Molecular balance is moved to the direction of producing ester, simultaneously along with liquid phase moisture reduction gradually in the process that column plate descends, effectively suppressed the back reaction that ester is hydrolyzed mutually.
By the design to the liquid residence time of the number of plates in the reactor and every fast column plate, require to make carboxylic acid content in the bottom product less than 1mol%.By enough pure steam is provided, driving a reaction liquid produces laterally and stirs, and the 11 pairs of suspension of bubble that rise simultaneously radially stir, and have effectively guaranteed the suspended state of acid-exchange resin particulate in suspension in the liquid phase circulation.The inclination angle of inclined plane of cone 7 and ring section 8 tilts to the below of distributor, so that the suspension below does not have obvious resin to stagnate.If necessary, can add inert gas in ascending air, what usually add is byproduct of reaction ether.For example acidic catalyst can promote the alcohol reaction to generate ether.Can generate when using methyl alcohol as raw material when dimethyl ether uses ethanol as raw material and can generate diethyl ether.These two kinds may be used to guarantee the liquid suspension on the column plate or are used for taking away the water that esterification generates.
What Fig. 2 described is main air entraining pipe 13 and the distribution situation of propping up air entraining pipe 14 on the tower tray, and an air entraining pipe can arrange suitable number according to the reactor scale.
What Fig. 3 described is air entraining pipe cross-sectional structure schematic diagram, structure and the work raw material of expression fish gill formula gas distributor.Air entraining pipe 20 outside suit membrane casings 21, suitable notch 22 is offered in air entraining pipe 20 bottoms, and the membrane casing of establishing of the edge on notch 22 long limits arranges scarfing 23.Lower in working order, gas is via notch 22 ejections of air entraining pipe, and under the effect of air-flow shear stress, the scarfing 23 of membrane casing opens, and air-flow is separated into minute bubbles and enters reaction bed.Air-flow forms turbulent flow in the scarfing exit, turbulent flow is to scarfing place Transverse Shear stress, and the size of shear stress is fixed through the gas quick decision of scarfing by gas flow, and this shear stress supports scarfing and opens, and this turbulent area plays fragmentation to bubble simultaneously.The folding situation of scarfing is fixed by gas quick decision, and gas speed determines by inlet amount and tower pressure drop, thus the scarfing openings of sizes along with the enhancing of tower pressure drop, weaken and change, opening became large when the tower pressure drop strengthened; Openings get smaller when the tower pressure drop reduces, bubble diminished when gas flowed out; Scarfing is not closed when having gas to flow out, and effectively prevents the reactant liquor suck-back, and avoids catalyst to drain on next piece column plate.Effect by scarfing effectively reduces air-flow to the washing away of catalyst granules, and has improved the service life of catalyst.
Theoretical cam curve in the reactor is not must be consistent with number of actual plates, and the theoretical cam curve of reactor may change along with the variation of acid in the charging, if the acid in the charging changes, the acid content at the bottom of the tower in the methyl esters product also may change.
The above has mentioned the common ether like binary of esterification byproduct.The yield of accessory substance ether depends on the operating temperature of reactor.Therefore the operating temperature that reduces reactor can reduce the generation of any accessory substance.Yet the conversion ratio of the lower acid generation of temperature ester is lower in theory.Under this condition, need the method that the excessive alcohol of ester phase product adding reacts is again improved the conversion ratio of ester phase.Usually contain 97mol% in the ester phase product to ester and the number acid raw material of 99mol%, the mixing mol ratio that adds the excessive pure and mild ester of alcohol (such as methyl alcohol) be 2:1 between the 4:1 such as 3:1.
Concerning the majority reaction, acid or monoesters are the downward vapor stream of liquid phase stream alcohol for rising.Boiling point such as tartaric acid or monoesters is lower than alcohol, and so pure and mild acid (or monoesters) component can be exchanged, and is that alcohol is liquid phase, then makes progress and pure counter current contacting to dirty and sour (or monoesters) steam from the column plate of reactor.
Further specify method of the present invention and effect below by embodiment.The percentage composition that relates to is molar content.
Embodiment
Use for laboratory reactor, internal diameter are 60mm, and material is glass, and 10 blocks of column plates are installed up and down in the reactor.Reactor is incubated and is heated by outside ribbon heater.Every block of column plate has independently temperature-controlling system.First block of column plate (column plate of topmost) is as washing not loaded resin of column plate.Second block of column plate is as the charging aperture of acid starting material.All the other 8 blocks of column plates all are equipped with a certain amount of strong acid ion exchange resin.Setting rotary gas distributor as shown in Figure 2 is 1 on the column plate of loaded resin catalyst.Methyl alcohol is heated to 150 ℃, and methanol steam enters reactor by the column plate of reactor lowermost end.On every fast column plate 200ml liquid is arranged.The resin loadings is calculated as 18% of liquid weight on the column plate with dried resin on the column plate.The reaction overhead gas contains unreacted methyl alcohol, the water of esterification generation and a small amount of accessory substance dimethyl ether and is cooled.Usually tower head is installed the liquid flooding device with the ester product loss rate in the control reactor.
Reactor is opened and is used the dodecanoate loaded resin when making.After the methanol steam on every block of column plate and temperature are all stablized, begin the phase reactor charging, contain the myristic acid of 50mol% laurate, 40mol% laurate and 10mol% in the material.Product ester to reactor bottom is monitored, until reach molecular balance.Liquid phase analysis on the different column plates the results are shown in following table 1; Column plate is numbered 1 to 10 from top to bottom, and the column plate of cat head is No. 1, and the column plate at the bottom of the tower is No. 10.
Table 1 embodiment reaction effect.
| Alcohol: sour mol:mol | 5：1 | 4：1 | 3：1 |
| Total |
3 | 2.5 | 2.0 |
| Column plate number | The concentration mol% of ester | The concentration mol% of ester | The concentration mol% of |
| 5 | 99.72 | 99.04 | 98.29 |
| 6 | 99.91 | 99.42 | 98.98 |
| 7 | 99.98 | 99.89 | 99.61 |
| 8 | 100.00 | 99.97 | 99.87 |
| 9 | 100.00 | 100.00 | 99.96 |
| 10 | 100.00 | 100.00 | 100.00 |
| Dimethyl ether by-product rate mol% | 2.0 | 1.5 | 0.6 |
Table 2 comparative example reaction effect.
| Alcohol: sour mol:mol | 5：1 | 4：1 | 3：1 |
| Total |
3 | 2.5 | 2.0 |
| Column plate number | The concentration mol% of ester | The concentration mol% of ester | The concentration mol% of |
| 5 | 98.02 | 95.21 | 94.87 |
| 6 | 99.21 | 98.35 | 96.83 |
| 7 | 99.55 | 98.73 | 96.98 |
| 8 | 99.73 | 98.95 | 97.52 |
| 9 | 99.89 | 99.26 | 98.94 |
| 10 | 99.92 | 99.47 | 99.15 |
| Dimethyl ether by-product rate mol% | 3.5 | 3.2 | 1.9 |
Comparative example
With the equipment and process condition identical with embodiment, be to offer common aperture on gas distributor is gas is distributed, reaction effect sees Table 2.
Claims (10)
1. esterifier, comprise tower-like reactor shell, at least one deck column plate is installed in the housing, solid esterification catalyst bulk storage is on column plate, downspout and the riser of column plate passed in setting, liquid level on downspout upper end open and the column plate is suitable, the downspout lower openings stretches into below the adjacent lower floor column plate liquid level, riser is communicated with gas distributor in the position on column plate top, it is characterized in that: gas distributor is fish gill formula gas distributor, gas distributor is made of air entraining pipe and the fish gill formula distribution of gas mouth that is distributed on the air entraining pipe, air entraining pipe is connected on the riser, the notch of inclination is set on air entraining pipe the latter half cylinder, notch outside cover film sleeve pipe, the edge on the long limit of the corresponding air entraining pipe notch of membrane casing has scarfing.
2. according to reactor claimed in claim 1, it is characterized in that: air entraining pipe comprises main air entraining pipe and an air entraining pipe, and main air entraining pipe is Straight, and main air entraining pipe is communicated with riser, propping up air entraining pipe is spirally coiled or Straight, and an air entraining pipe is communicated with on main air entraining pipe.
3. according to reactor claimed in claim 1, it is characterized in that: the distance of air entraining pipe and column plate is 100mm ~ 500mm, and the inclined notch on the air entraining pipe is bar shaped, and the width of notch is greater than 1.5mm, and the length of notch is 5%～30% of air entraining pipe girth; The angle of inclination of notch is 15～75 degree.
4. according to reactor claimed in claim 1, it is characterized in that: the distance of air entraining pipe and column plate is 100mm ~ 200mm, and the inclined notch on the air entraining pipe is bar shaped, and the width of notch is 2～20mm, and the angle of inclination of notch is 30～50 degree.
5. according to reactor claimed in claim 1, it is characterized in that: the scarfing of the membrane casing that air entraining pipe notch outside covers is arranged on the edge on the long limit of air entraining pipe notch, and scarfing is arranged on the edge on any long limit in two long limits of air entraining pipe notch.
6. according to claim 1 or 5 described reactors, it is characterized in that: the length of scarfing is 70%～150% of air entraining pipe notch length.
7. according to claim 1 or 5 described reactors, it is characterized in that: the material of the membrane casing that air entraining pipe notch outside covers is that corrosion resistant alloy foil sheet is made, perhaps make for the non-metal anti-corrosion material, perhaps make for the composite film material of alloy and non-metal anti-corrosion material.
8. according to reactor claimed in claim 1, it is characterized in that: column plate quantity is 3 ~ 50.
9. the production method of a dimethyl maleate, it is characterized in that right to use requires the described esterifier of 1 to 9 arbitrary claim, take monomethyl maleate and methyl alcohol as raw material, take storng-acid cation exchange resin as catalyst, monomethyl maleate is introduced from reactor head with liquid form, methyl alcohol is introduced from reactor bottom with the gas phase form, and 10～40 sieve plates are set in the reactor, obtains dimethyl maleate after the reaction and draws reactor from reactor bottom.
10. in accordance with the method for claim 9, it is characterized in that: the concrete reaction condition of dimethyl maleate production is: the mol ratio 1:1.5 of maleic acid mono alkyl ester/alkylol～1:5, the liquid phase feeding of maleic acid mono alkyl ester is 0.2h to the cumulative volume air speed of resin catalyst
-1～2.0h
-1, reaction temperature is 90 ℃～160 ℃, reactor bottom inlet steam pressure limit is that 0.1MPa is to 3MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110217525.7A CN102908956B (en) | 2011-08-01 | 2011-08-01 | Esterification reactor and production method of dimethyl maleate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110217525.7A CN102908956B (en) | 2011-08-01 | 2011-08-01 | Esterification reactor and production method of dimethyl maleate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102908956A true CN102908956A (en) | 2013-02-06 |
| CN102908956B CN102908956B (en) | 2015-06-17 |
Family
ID=47607671
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110217525.7A Active CN102908956B (en) | 2011-08-01 | 2011-08-01 | Esterification reactor and production method of dimethyl maleate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102908956B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108283820A (en) * | 2018-01-04 | 2018-07-17 | 中石化上海工程有限公司 | Reactive Stage with claw gas distributor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1861749A (en) * | 2005-05-12 | 2006-11-15 | 中国石油化工股份有限公司 | Production process of biological diesel |
| CN101254444A (en) * | 2007-12-05 | 2008-09-03 | 南京大学 | Catalytic reaction, rectification integrated technique and special-purpose equipment |
| CN101618304A (en) * | 2008-07-04 | 2010-01-06 | 中国石油化工股份有限公司 | Esterification reactor |
-
2011
- 2011-08-01 CN CN201110217525.7A patent/CN102908956B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1861749A (en) * | 2005-05-12 | 2006-11-15 | 中国石油化工股份有限公司 | Production process of biological diesel |
| CN101254444A (en) * | 2007-12-05 | 2008-09-03 | 南京大学 | Catalytic reaction, rectification integrated technique and special-purpose equipment |
| CN101618304A (en) * | 2008-07-04 | 2010-01-06 | 中国石油化工股份有限公司 | Esterification reactor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108283820A (en) * | 2018-01-04 | 2018-07-17 | 中石化上海工程有限公司 | Reactive Stage with claw gas distributor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102908956B (en) | 2015-06-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0454719B1 (en) | A continuous process for the production of carboxylic acid esters | |
| CN101618304B (en) | Esterification reactor | |
| US8895765B2 (en) | Method and apparatus for preparing alkyl ester fatty acid using fatty acid | |
| US7420072B2 (en) | Apparatus and method for producing biodiesel fuel | |
| US20220410104A1 (en) | Gas-liquid bubbling bed reactor, reaction system, and process for synthesizing carbonate ester | |
| US8530684B2 (en) | Method for preparing fatty acid alkyl ester using fatty acid | |
| CN103201247A (en) | Pump around reactor for production of acetic acid | |
| CN102908956B (en) | Esterification reactor and production method of dimethyl maleate | |
| CN102908955B (en) | The preparation method of macroporous plate esterifier and dimethyl maleate | |
| JP2022117587A (en) | Method for producing secondary alcohol alkoxylate | |
| EP2635370B1 (en) | Apparatus and method | |
| CN103221375A (en) | Production of acetic acid with an increased production rate | |
| RU2036713C1 (en) | Reactor for conducting reactions in gas-liquid phase, mainly by air oxidation of n-xylene and monomethyl ester of toluic acid | |
| WO2009038864A1 (en) | Method for obtaining biodiesel, alternative fuels and renewable fuels tax credits and treatment | |
| CN107540522A (en) | A kind of production technology of sec-butyl alcohol | |
| CN111747849A (en) | Method for synthesizing n-propyl acetate by continuous catalytic esterification of benzenesulfonic acid and derivatives thereof | |
| CN104673502A (en) | Continuous esterification technique for producing biodiesel from waste grease | |
| JP2022117589A (en) | Method for producing secondary alcohol alkoxylate | |
| NZ611362B2 (en) | A heterogeneous catalytic reaction apparatus and method | |
| SG184680A1 (en) | A method for producing biodiesel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |