CN111018647A

CN111018647A - Butene isomerization process

Info

Publication number: CN111018647A
Application number: CN201811175355.9A
Authority: CN
Inventors: 龚海燕; 刘俊涛; 孙凤侠
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2018-10-10
Filing date: 2018-10-10
Publication date: 2020-04-17

Abstract

The invention relates to a butene isomerization method. The method comprises the steps of contacting a stream containing 2-butene with a catalyst to obtain 1-butene; the catalyst comprises 30-100 parts by weight of MCM mesoporous molecular sieve and 0-70 parts by weight of binder, wherein the catalyst is relative to the total weight of the MCM mesoporous molecular sieve and the binder.

Description

Butene isomerization process

Technical Field

The invention relates to a butene isomerization method.

Background

1-butene is α -olefin with relatively active chemical property, is mainly used for producing Linear Low Density Polyethylene (LLDPE), High Density Polyethylene (HDPE), Polybutylene (PB) resin, decanol and the like, and has wide application, in recent years, the global demand for polyethylene is rapidly increased, so the demand for 1-butene serving as a comonomer is increased, however, most of domestic 1-butene manufacturers are self-used and rarely sell the 1-butene to other parts, so the purchase of the 1-butene is relatively difficult, and particularly, enterprises with relatively large gaps for the 1-butene exist.

Currently, there are two main routes for global 1-butene production, one is oligomerization process using ethylene as raw material, and the other is refinery C₄C, cracking₄Or coal-to-olefin byproduct mixed C₄Is obtained by separating raw materials. The latter is commonly adopted in China for the mixed C₄Butadiene extraction and hydrogenation are carried out, isobutene is removed through etherification, and then 1-butene products are obtained through rectification separation. But of the 1-butene of the schemeThe yield is limited by the source of 1-butene in the feed. Most petrochemical companies in the world use residual C rich in 2-butene₄Hydrocarbons are used as fuels. If the part of 2-butene is converted into 1-butene through isomerization reaction, a new path for producing the 1-butene can be opened up.

However, since the isomerization reaction temperature of butene double bonds is high, carbon deposition is easily generated on the acidic catalyst by olefin, and if the carbon deposition amount is too large, the active sites of the catalyst are covered, so that the activity of the catalyst is lost. Therefore, the technology must solve the problem of carbon deposition of the catalyst in the industrial process and improve the stability period of the catalyst.

In recent years, a great deal of research and development has been carried out on the process for producing 1-butene by isomerizing 2-butene by related petrochemical companies at home and abroad. For example, CN102267853A discloses a method for producing 1-butene by isomerizing 2-butene, which adopts a surface area of 150-210 m²Taking alumina per gram as a carrier, dissolving 0.146-23.82 parts by weight of metal salt in 82-100 parts by weight of deionized water to prepare an aqueous solution, and then soaking 57 parts by weight of catalyst carrier; standing and soaking for 16-24 hours at room temperature, filtering out residual liquid, drying for 4-10 hours at the temperature of 120-160 ℃ until water is completely removed, and roasting for 1-12 hours at the temperature of 500-600 ℃ to obtain a metal composite oxide catalyst; the catalyst prepared by the method is filled in a fixed bed catalytic reactor, 2-butene gas with the content of 85.0-99.0% passes through a catalytic cracking bed layer, the temperature is 300-480 ℃, the pressure is 0.1-0.5 Mpa, and the gas hourly space velocity of the feed of the 2-butene is 60-900 hours^-1Carrying out double-bond isomerization reaction under the condition of (1), and carrying out timing sampling analysis on gas after the reaction to obtain the 1-butene with the content of 19.0-27.0%.

The document CN1511126 uses an alkaline metal oxide such as magnesium oxide, especially high-purity magnesium oxide as a catalyst, and performs butene double bond isomerization reaction at 300-500 ℃, and the service life of the catalyst is only dozens of hours, which cannot satisfy long-period industrial application.

Disclosure of Invention

The present inventors have assiduously studied on the basis of the prior art, and have accomplished the present invention by solving at least one of the aforementioned problems by adopting a technical solution in which an MCM molecular sieve is used as an active component of a catalyst.

Specifically, the invention relates to a butene isomerization method, which comprises the steps of contacting a stream containing 2-butene with a catalyst to obtain 1-butene; the catalyst comprises 30-100 parts by weight of MCM mesoporous molecular sieve and 0-70 parts by weight of binder, wherein the catalyst is relative to the total weight of the MCM mesoporous molecular sieve and the binder.

According to one aspect of the invention, the catalyst comprises 40-90 parts by weight of MCM mesoporous molecular sieve and 10-60 parts by weight of binder, preferably 50-80 parts by weight of MCM mesoporous molecular sieve and 20-50 parts by weight of binder, relative to the total weight parts of MCM mesoporous molecular sieve and binder.

According to one aspect of the present invention, the MCM mesoporous molecule is screened for at least one of the group consisting of MCM-41, MCM-48 and MCM-50, preferably MCM-41.

According to an aspect of the present invention, the binder is at least one selected from the group consisting of alumina and silica.

According to one aspect of the invention, the catalyst further comprises 0.1-1 part of framework zirconium.

According to one aspect of the invention, the catalyst does not contain an alkaline earth metal element or an oxide thereof.

According to an aspect of the present invention, the alkaline earth metal element is at least one selected from the group consisting of magnesium, calcium, strontium, and barium; in particular magnesium.

According to one aspect of the invention, the conditions under which the 2-butene-containing stream is contacted with the catalyst comprise: the contact temperature is 210-420 ℃, the pressure is 0-1 MPa, and the weight space velocity is 1-10 hours^-1(ii) a The preferable contact temperature is 250-350 ℃, the pressure is 0.5-1 MPa, and the weight space velocity is 2-5 hours^-1。

According to one aspect of the invention, the stream containing 2-butene is derived from a refinery catalytic cracking unit, an ethylene plant steam cracking unit or a coal-to-olefin unit byproduct mixed C-IV stream, preferably a C-IV stream obtained by removing 1, 3-butadiene and isobutene from the refinery catalytic cracking unit, the ethylene plant steam cracking unit or the coal-to-olefin unit byproduct mixed C-IV stream.

According to one aspect of the invention, said 2-butene-containing stream is a mixture comprising 1-butene and 2-butene which does not meet thermodynamic equilibrium values.

According to one aspect of the invention, the 2-butene-containing stream has a mass concentration of 1-butene of less than 4% and a mass concentration of 2-butene of greater than 45%.

According to one aspect of the invention, the mass concentration of 1, 3-butadiene in the 2-butene-containing stream is less than 30 ppm.

The invention has the beneficial effects that:

according to the process of the invention, the conversion of 2-butene is high, close to the thermodynamic equilibrium conversion at this temperature. For example, at a reaction temperature of 305 ℃, a reaction pressure of 0.4MPa and a weight space velocity of 5 hours^-1Under the conditions, the 2-butene conversion is more than 20 wt%, and the thermodynamic equilibrium conversion is close to 20.25 wt%.

According to the method, the catalyst is not easy to deposit carbon and has good stability, and the activity is kept unchanged after the reaction is carried out for 3500 hours.

The invention is further described below by means of specific embodiments.

Detailed Description

The following describes in detail specific embodiments of the present invention. It is to be noted, however, that the scope of the present invention is not limited thereto, but is defined by the appended claims.

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

When the specification concludes with claims with the heading "known to those skilled in the art", "prior art", or the like, to derive materials, substances, methods, procedures, devices, or components, etc., it is intended that the subject matter derived from the heading encompass those conventionally used in the art at the time of filing this application, but also include those that are not currently in use, but would become known in the art to be suitable for a similar purpose.

In the context of the present specification, anything or things which are not mentioned, except where explicitly stated, are directly applicable to those known in the art without any changes. Moreover, any embodiment described herein may be freely combined with one or more other embodiments described herein, and the technical solutions or concepts resulting therefrom are considered part of the original disclosure or original disclosure of the invention, and should not be considered as new matters not disclosed or contemplated herein, unless a person skilled in the art would consider such a combination to be clearly unreasonable.

Unless otherwise expressly indicated, all percentages, parts, ratios, etc. mentioned in this specification are by weight unless otherwise not in accordance with the conventional knowledge of those skilled in the art.

Where not explicitly stated, reference to pressure within this specification is to gauge pressure.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein. In the following, various technical solutions can in principle be combined with each other to obtain new technical solutions, which should also be regarded as specifically disclosed herein.

It should be noted that the 2-butene double bond isomerization reaction to produce 1-butene is typically a reversible reaction, and generally the distribution of butene isomerization products is mainly controlled by thermodynamic factors. Therefore, different thermodynamic equilibrium conversions will be associated at different temperatures. Thermodynamic equilibrium conversion can be thermodynamically calculated for the reaction process by means of the Gibbs free energy minimum principle, which is well known to those skilled in the art.

The invention relates to a butene isomerization method. The method comprises the steps of contacting a stream containing 2-butene with a catalyst to obtain 1-butene; the catalyst comprises 30-100 parts by weight of mesoporous MCM molecular sieve and 0-70 parts by weight of binder, and the catalyst is relative to the total weight parts of the mesoporous MCM molecular sieve and the binder.

According to the invention, the mesoporous MCM molecular sieve in the catalyst has regular mesoporous channels (2-50 nm), larger specific surface area and channel volume, is not only an active component of the catalyst, provides an acid site for reaction, and ensures the activity and selectivity of the reaction; and is also C₄The diffusion of the carbon-containing catalyst provides a large pore channel, accelerates the diffusion of reactants and products in the reaction process and reduces the carbon deposition speed.

According to the present invention, the MCM mesoporous molecule screens at least one of the group consisting of MCM-41, MCM-48 and MCM-50, preferably MCM-41. Wherein, the MCM mesoporous molecule screening comprises at least one of the group consisting of MCM-41, MCM-48 and MCM-50, not only comprises a mechanical mixture of at least two selected from the group consisting of MCM-41, MCM-48 and MCM-50, but also comprises an eutectic molecular sieve of at least two selected from the group consisting of MCM-41, MCM-48 and MCM-50. The eutectic molecular sieve described herein, which is also referred to in the art as intergrown molecular sieve, is distinguished from a simple mechanical mixture by the fact that crystals of several morphologies aggregate with one another, a growing conglomerate, crystallize together, you in me.

According to the present invention, the binder is at least one selected from the group consisting of alumina and silica.

According to the invention, the catalyst also comprises framework zirconium, so that the acidic active site of the catalyst is modified, and the stability of the catalyst is further enhanced. 0.1 to 1 part, for example 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 part, calculated as parts by weight on an elemental basis, in the final catalyst composition.

According to an embodiment of the present invention, the catalyst does not contain an alkaline earth metal element or an oxide thereof from the viewpoint of more favorable isomerization reaction. The alkaline earth metal element is at least one selected from the group consisting of magnesium, calcium, strontium, and barium; in particular magnesium.

According to the invention, the contact temperature is 210-420 ℃, the pressure is 0-1 MPa, and the weight space velocity is 1-10 hours^-1(ii) a The preferable contact temperature is 250-350 ℃, the pressure is 0.5-1 MPa, and the weight space velocity is 2-5 hours^-1。

According to the invention, the stream containing 2-butene is derived from a refinery catalytic cracking unit, an ethylene plant steam cracking unit or a coal-to-olefin unit byproduct mixed C-IV stream, and preferably is derived from a refinery catalytic cracking unit, an ethylene plant steam cracking unit or a coal-to-olefin unit byproduct mixed C-IV stream from which 1, 3-butadiene and isobutene are removed.

According to the invention, said stream comprising 2-butene is a mixture comprising 1-butene and 2-butene which does not comply with thermodynamic equilibrium values.

According to the invention, the 2-butene-containing stream has a mass concentration of 1-butene lower than 4% and a mass concentration of 2-butene higher than 45%.

According to the invention, the mass concentration of 1, 3-butadiene in the stream containing 2-butene is preferably less than 30 ppm. Too much 1, 3-butadiene in the feed will produce a large amount of polymer, which affects not only the product quality but also the stability of the catalyst.

In the process of the present invention, the catalyst can be prepared by the following method. The method comprises the following steps: crystallizing a mixture (hereinafter collectively referred to as a mixture) comprising a template, a zirconium source, a silicon source, and water to obtain a mesoporous MCM molecular sieve, and a step of molding the mesoporous MCM molecular sieve with a binder.

Wherein, in order to make the template agent and the zirconium source better dissolved in water, acid or alkali can be added. These acids or bases may be any acids or bases conventionally used in the art for this purpose, such as hydrochloric acid, sulfuric acid, NaOH, KOH.

The zirconium source, any zirconium source conventionally used in the art for this purpose may be used, including but not limited to zirconium nitrate, zirconium oxychloride, and zirconium isopropoxide, with zirconium nitrate and zirconium oxychloride being preferred.

As the template, any template conventionally used in the art for synthesizing mesoporous MCM molecular sieves may be used, and examples thereof include cetyltrimethylammonium bromide, cetyltrimethylammonium hydroxide, polyethylene glycol octylphenyl ether emulsifier, and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123. These templating agents may be used singly or in combination in a desired ratio.

As the silicon source, any silicon source conventionally used in the art for this purpose can be used. Examples thereof include sodium silicate, silica sol and silicate ester. These silicon sources may be used singly or in combination in a desired ratio.

In the mixture, the template agent and the zirconium source (as ZrO)₂Calculated), the silicon source (in SiO)₂Calculated) and water in a molar ratio of: 0.1-0.8: 0-0.13: 1: 35-170; preferably: 0.2-0.5: 0.005-0.025: 1: 35-170.

The crystallization may be performed in any manner conventionally known in the art, for example, a method of subjecting the mixture to hydrothermal crystallization under crystallization conditions may be exemplified. Crystallization may be in the presence of stirring as desired. The crystallization conditions include: the temperature is 80-170 ℃ and the time is 18-200 hours.

Preferably, an ageing step is included, carried out before crystallization, the ageing conditions including: the aging temperature is 30-85 ℃, and the aging time is 1-4 hours.

After the crystallization is completed, the mesoporous molecular sieve may be separated from the obtained reaction mixture by any separation means conventionally known. The separation method includes, for example, a method of filtering, washing and drying the obtained product mixture. Here, the filtering, washing and drying may be performed in any manner conventionally known in the art. As a specific example, as the filtration, for example, the obtained product mixture may be simply filtered with suction. Examples of the washing include washing with deionized water and/or ethanol. The drying temperature is, for example, 40 to 250 ℃, preferably 60 to 150 ℃, and the drying time is, for example, 8 to 30 hours, preferably 10 to 20 hours. The drying may be carried out under normal pressure or under reduced pressure.

If necessary, the crystallized mesoporous molecular sieve may be calcined to remove the organic template and water, etc., which may be present, thereby obtaining the calcined molecular sieve. The calcination can be carried out in any manner conventionally known in the art, for example, the calcination temperature is generally 300 to 800 ℃, preferably 400 to 650 ℃, and the calcination time is generally 1 to 10 hours, preferably 3 to 6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as air or oxygen.

And mixing the mesoporous molecular sieve and a binder, and molding to obtain the catalyst. The catalyst may be in the form of any molded article (e.g., a bar, a clover, etc.), and may be obtained in any manner conventionally known in the art, without particular limitation. As the binder, any binder conventionally used in the art for this purpose can be used. For example, alumina or silica can be cited. Preferably, a pore-forming agent may be added during molding. As the porogen, any porogen conventionally used in the art for this purpose can be used. Examples thereof include sesbania powder and methyl cellulose.

The molded catalyst may be dried and calcined as necessary. The drying may be carried out in any manner conventionally known in the art, and the drying temperature may be, for example, 40 to 250 ℃, preferably 60 to 150 ℃, and the drying time may be, for example, 8 to 30 hours, preferably 10 to 20 hours. The drying may be carried out under normal pressure or under reduced pressure. The calcination can be carried out in any manner conventionally known in the art, for example, the calcination temperature is generally 300 to 800 ℃, preferably 400 to 650 ℃, and the calcination time is generally 1 to 10 hours, preferably 3 to 6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as air or oxygen.

In the preparation method of the catalyst, the mixture does not contain an alkaline earth metal source from the viewpoint of more favorable isomerization reaction. The alkaline earth metal is at least one selected from the group consisting of magnesium, calcium, strontium, and barium; in particular magnesium. The phrase "not including an alkaline earth metal source" as used herein means that the alkaline earth metal source is not intentionally or actively introduced during the production process.

In the present invention, the composition of the catalyst was analyzed by ICP (inductively coupled plasma) and XRF (X-ray fluorescence) methods. ICP is used to test the metal content of catalysts, such as zirconium, magnesium, under the test conditions: an iCAP7600Duo inductively coupled plasma emission spectrometer of American Sammer Feishell company is adopted, zirconium oxide is used as a standard sample, and the RF power of the instrument is 1.2 KW; the carrier gas flow is 0.72L/min; the flow rate of the cooling gas is 15L/min; the pump flow rate was 1.0ml/min and the analytical wavelength was 335 nm. XRF was used to test the content of molecular sieve in the catalyst under the following test conditions: a Rigaku ZSX 100e type XRF instrument is adopted, a rhodium target is used as an excitation source, the maximum power is 3600W, the tube voltage is 60KV, and the tube current is 120 mA.

The analysis of the crystalline phase of the catalyst in the invention is carried out on a Bruker D8 polycrystalline X-ray diffraction (XRD) instrument, a graphite monochromator, a Cu-Ka ray source (K α 1 with the wavelength lambda of 0.15406nm), a scanning angle 2 theta of 5-50 degrees and a scanning speed of 1 DEG/min.

The Zr existence form of the catalyst is determined by adopting a Cary5000 type ultraviolet-visible spectrum (UV-vis) instrument, solid barium sulfate is taken as a reference, and the test wavelength range is 190-800. The multi-coordination zirconium in the molecular sieve framework can generate an absorption peak at the wavelength of 240-280 nm, and the absorption peak of the zirconium oxide is less than 200 nm.

In the invention, the carbon deposition speed of the catalyst is tested by adopting an SDT Q600 type thermal analyzer of the American TA company, the weight loss curve of a sample is measured under the air atmosphere, the test temperature is 25-800 ℃, and the heating rate is 10 ℃/min.

In the invention, the product composition is determined by gas chromatography, the chromatography model is Agilent 7890A, a FID detector is arranged, an FFAP capillary chromatographic column is used for separation, the temperature of the chromatographic column is programmed to be 90 ℃ initially, the chromatographic column is kept for 15 minutes, and then the temperature is increased to 220 ℃ at the speed of 15 ℃/minute and kept for 45 minutes.

The conversion X of 2-butene is calculated as:

X(_2-butene)＝(M_{Import 2-butene}-M_{Outlet 2-butene})/M_{Import 2-butene}×100％

The selectivity Y of 1-butene is calculated by the formula:

Y(_1-butene)＝M(_{Outlet 1-butene})/(M_{Import 2-butene}-M_{Outlet 2-butene})×100％

The present invention is further illustrated by the following examples.

[ example 1 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.2:0.0032:0.5:1: 55.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 100 ℃ for 85 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-41 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis.

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A1.

The catalyst composition is shown in table 1.

[ example 2 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water content of 0.2:0.0032:0.5:1:55。

And (3) kneading 65g of the molecular sieve, 35g of alumina, 60ml of 0.5% nitric acid and 5g of sesbania powder, extruding into strips, drying at 120 ℃ for 4 hours, and roasting at 500 ℃ for 4 hours to obtain the catalyst A2.

The catalyst composition is shown in table 1.

[ example 3 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.2:0.0028:0.5:1: 55.

Taking 75g and 63g of silica Sol (SiO) of the molecular sieve₂40 percent of the content), 30ml of water and 5g of sesbania powder are kneaded and extruded into strips, the strips are baked for 4 hours at 120 ℃, and then the strips are baked for 4 hours at 500 ℃ to obtain the catalyst A3.

The catalyst composition is shown in table 1.

[ example 4 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethylammonium bromide, zirconium nitrate (calculated as ZrO 2), sodium hydroxide, tetraethyl orthosilicate (calculated as SiO 2), and water at 0.2:0.0023:0.5:1: 55.

Taking 90g and 25g of silica Sol (SiO) of the molecular sieve₂Content 40%), 80ml of water and 5g of sesbania powder, kneading, extruding, baking at 120 ℃ for 4 hours, and baking at 500 ℃ for 4 hours to obtain the catalyst A4.

The catalyst composition is shown in table 1.

[ example 5 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.2:0.0052:0.5:1: 55.

Taking 40g and 80g of silica Sol (SiO) of the molecular sieve₂40 percent of content), 28g of silicon oxide powder and 5g of sesbania powder are kneaded and extruded into strips, the strips are baked for 4 hours at 120 ℃, and then the strips are baked for 4 hours at 500 ℃ to obtain the catalyst A5.

The catalyst composition is shown in table 1.

[ example 6 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.2:0.0069:0.5:1:55。

Taking 30g and 80g of silica Sol (SiO) of the molecular sieve₂40 percent of content), 38g of silicon oxide powder and 5g of sesbania powder are kneaded and extruded into strips, the strips are baked for 4 hours at 120 ℃, and then the strips are baked for 4 hours at 500 ℃ to obtain the catalyst A6.

The catalyst composition is shown in table 1.

[ example 7 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.2:0.0021:0.5:1: 55.

And (3) uniformly mixing 100g of the molecular sieve and 5g of sesbania powder, tabletting, baking at 120 ℃ for 4 hours, and baking at 500 ℃ for 4 hours to obtain the catalyst A7.

The catalyst composition is shown in table 1.

[ example 8 ]

Cetyl trimethylammonium bromide was dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium bromide, sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of weight percent), the ratio of water to water is 0.2:0.5:1: 55.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 100 ℃ for 85 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the type of the molecular sieve to be MCM-41 by XRD (X-ray diffraction) characterization of the molecular sieve powder.

And (3) kneading 65g of the molecular sieve, 35g of alumina, 60ml of 0.5% nitric acid and 5g of sesbania powder, extruding into strips, drying at 120 ℃ for 4 hours, and roasting at 500 ℃ for 4 hours to obtain the catalyst A8.

The catalyst composition is shown in table 1.

[ example 9 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of weight percent), the ratio of water to water is 0.2:0.013:0.5:1: 55.

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A9.

The catalyst composition is shown in table 1.

[ example 10 ]

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 100 ℃ for 85 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-48 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis.

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A10.

[ example 11 ]

Cetyl trimethyl ammonium bromide, polyethylene glycol octyl phenyl ether emulsifier and zirconium nitrate were dissolved in 2000ml of deionized water to obtain a mixture I. Ethyl orthosilicate was added slowly and dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethylammonium bromide: polyethylene glycol octyl phenyl ether emulsifier zirconium nitrate (with ZrO)₂Hydrochloric acid, tetraethoxysilane (in SiO)₂In terms of water, 0.25:0.005:0.0032:0.5:1: 55.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 135 ℃ for 120 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve types to be MCM-41 and 48 eutectic molecular sieves containing skeleton zirconium by characterization of XRD and UV-vis.

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A11.

The catalyst composition is shown in table 1.

[ example 12 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium Bromide zirconium nitrate (as ZrO)₂Sodium hydroxide, ethyl orthosilicate (in SiO)₂In terms of water, 0.8:0.0032:0.5:1: 55.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 120 ℃ for 200 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-50 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis. .

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A12.

The catalyst composition is shown in table 1.

[ example 13 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethylammonium bromide zirconium nitrate (calculated as ZrO 2), potassium hydroxide ethyl orthosilicate (calculated as SiO)₂In terms of water, 0.15:0.0032:0.5:1: 35.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 165 ℃ for 130 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-41 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis. .

Taking 65g and 88g of silica Sol (SiO) of the molecular sieve₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A13.

The catalyst composition is shown in table 1.

[ example 14 ]

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. The silica sol was slowly added dropwise to the mixture I to obtain a mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethylammonium bromide zirconium nitrate (calculated as ZrO 2), sodium hydroxide ethyl orthosilicate (calculated as SiO)₂In terms of water, 0.2:0.0032:0.5:1: 55.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 100 ℃ for 85 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-41 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis. .

Taking 65g of the molecular sieve, 0.8g of magnesium oxide and 88g of silica Sol (SiO)₂Content 40%) and 5g sesbania powder, kneading, extruding, baking at 120 deg.C for 4 hr, and baking at 500 deg.C for 4 hr to obtain catalyst A14.

[ COMPARATIVE EXAMPLE 1 ]

The preparation conditions were as per [ example 1 ] except that the templating agent was changed and a portion of the aluminum sol was added to mixture II.

The template hexamethylimine and zirconium nitrate were dissolved in 2000ml of deionized water to obtain a mixture I. Adding ethyl orthosilicate and aluminum sol into the mixture I slowly and dropwise to obtain a mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethylammonium bromide zirconium nitrate (calculated as ZrO 2), sodium hydroxide ethyl orthosilicate (calculated as SiO)₂Aluminum sol (in terms of Al)₂O₃) The water was 0.2:0.0032:0.5:1: 355.

And placing the mixture II at 75 ℃ for 2 hours, then transferring the mixture II into a crystallization kettle for crystallization at 100 ℃ for 85 hours, filtering the obtained mixture, washing the mixture with ethanol and deionized water, drying the mixture at 120 ℃ and roasting the mixture at 550 ℃ for 4 hours to obtain molecular sieve powder, and determining the molecular sieve type to be the MCM-22 molecular sieve containing the skeleton zirconium by characterization of XRD and UV-vis.

And (3) kneading 65g of the molecular sieve, 88g of silica sol (the content of SiO2 is 40%) and 5g of sesbania powder, extruding into strips, baking for 4 hours at 120 ℃, and baking for 4 hours at 500 ℃ to obtain the catalyst B1.

[ COMPARATIVE EXAMPLE 2 ]

The procedure of [ example 1 ] was followed except that the proportion of molecular sieve was reduced during the subsequent catalyst formation.

Cetyl trimethylammonium bromide, zirconium nitrate were dissolved in 2000ml of deionized water to give mixture I. Ethyl orthosilicate was slowly added dropwise to mixture I to give mixture II. The molar ratio of each substance in the mixture II is as follows: cetyl trimethyl ammonium bromide nitric acidZirconium (with ZrO)₂Sodium hydroxide, ethyl orthosilicate (calculated as SiO 2) and water in a ratio of 0.2:0.0032:0.5:1: 55.

Taking 15g and 70g of silica Sol (SiO) of the molecular sieve₂Content 40%), 50g of silicon oxide and 5g of sesbania powder, kneading, extruding, baking at 120 ℃ for 4 hours, and baking at 500 ℃ for 4 hours to obtain the catalyst B2.

TABLE 1

[ example 15 ]

[ examples 1-14 ] the catalyst was evaluated for reaction.

A mixed C containing 13.2 wt% of n-butane, 34.7 wt% of cis-2-butene and 52.1 wt% of trans-2-butene₄As raw material, the reaction temperature is 305 ℃, the reaction pressure is 0.4MPa, and the weight space velocity is 5 hours^-1The catalysts were evaluated under the conditions. After 100 hours of evaluation, the catalyst was discharged for thermogravimetric analysis, and the carbon deposition amount was calculated, and the results are shown in table 2.

[ COMPARATIVE EXAMPLE 3 ]

[ comparative examples 1-2 ] the catalyst was used for evaluation of the reaction.

TABLE 2

As can be seen from Table 2, the isomerization catalyst of the present invention, when used in butene isomerization reaction, did not decrease the conversion with time and had low carbon deposition; and the carbon deposition amount after 100 hours of reaction is obviously lower than that of the catalyst in the comparative example, and the 2-butene conversion rate is higher than that of the catalyst in the comparative example. Therefore, the catalyst has good stability and anti-carbon deposition capability.

[ example 16 ]

The reaction materials were as in example 15, and the performance of catalyst A1 under different reaction conditions was examined. The reaction conditions and results are shown in Table 3.

TABLE 3

[ example 17 ]

The reaction materials were as described in example 15, and the stability of catalyst A1 in butene double bond isomerization was examined. At the reaction temperature of 305 ℃, the reaction pressure of 0.4MPa and the weight space velocity of 5 hours^-1Under the conditions, the catalyst was evaluated for stability over 3500 hours.

After 3500 hours, the conversion of 2-butene was 19.95%, the selectivity of 1-butene was 99.42%, and the conversion of 2-butene and the selectivity of 1-butene were substantially unchanged from those at the initial stage of the reaction.

The catalyst after being discharged is subjected to thermogravimetric analysis, the carbon deposition amount is 2.96mg/g, the carbon deposition amount is not obviously increased compared with the initial period, and the catalyst stability is good.

Table 4 catalyst stability evaluation data

Reaction time, hours	2-butene conversion%
		2	19.93
100	19.66
		300	19.76
500	19.37
		800	19.64
1500	19.46
		2000	19.53
3500	19.83

[ example 18 ]

The reaction materials were as described in example 15, and the stability of catalyst B1 in butene double bond isomerization was examined. At the reaction temperature of 305 ℃, the reaction pressure of 0.4MPa and the weight space velocity of 5 hours^-1Under the conditions, the catalysts were evaluated for stability for 600 hours.

After 600 hours the 2-butene conversion had dropped to 4.33% with substantial loss of activity. The catalyst after being discharged is subjected to thermogravimetric analysis, and the carbon deposition amount is up to 176 mg/g.

Table 5 catalyst stability evaluation data

Reaction time, hours	2-butene conversion%
		2	18.13
100	12.17
		200	9.55
300	7.20
		400	5.96
500	5.49
		600	4.89

Claims

1. A butene isomerization method, including the step of contacting the stream containing 2-butene with catalyst to obtain 1-butene; the catalyst comprises 30-100 parts by weight of MCM mesoporous molecular sieve and 0-70 parts by weight of binder, wherein the catalyst is relative to the total weight of the MCM mesoporous molecular sieve and the binder.

2. The butene isomerization process according to claim 1, wherein the catalyst comprises 40 to 90 parts by weight of the MCM mesoporous molecular sieve and 10 to 60 parts by weight of the binder, preferably 50 to 80 parts by weight of the MCM mesoporous molecular sieve and 20 to 50 parts by weight of the binder, relative to the total weight parts of the MCM mesoporous molecular sieve and the binder.

3. The butene isomerization process according to claim 1, wherein said MCM mesoporous molecules are screened for at least one of the group consisting of MCM-41, MCM-48 and MCM-50, preferably MCM-41.

4. The butene isomerization method according to claim 1, wherein the binder is at least one selected from the group consisting of alumina and silica.

5. The butene isomerization process according to claim 1, wherein the catalyst further comprises 0.1 to 1 part of skeletal zirconium.

6. The butene isomerization process according to claim 1, wherein the catalyst does not contain an alkaline earth metal element or an oxide thereof.

7. The butene isomerization method according to claim 6, wherein the alkaline earth metal element is at least one selected from the group consisting of magnesium, calcium, strontium and barium; in particular magnesium.

8. The butene isomerization process of claim 1, wherein the conditions under which the 2-butene-containing stream is contacted with the catalyst comprise: the contact temperature is 210-420 ℃, the pressure is 0-1 MPa, and the weight space velocity is 1-10 hours^-1(ii) a The preferable contact temperature is 250-350 ℃, the pressure is 0.5-1 MPa, and the weight space velocity is 2-5 hours^-1。

9. The butene isomerization method according to claim 1, wherein the stream containing 2-butene is derived from a refinery catalytic cracking unit, an ethylene plant steam cracking unit or a coal-to-olefins unit by-product mixed carbon four stream, preferably a carbon four stream obtained by removing 1, 3-butadiene and isobutene from a refinery catalytic cracking unit, an ethylene plant steam cracking unit or a coal-to-olefins unit by-product mixed carbon four stream.

10. Process for the isomerization of butenes according to claim 1, characterized in that the stream comprising 2-butenes is a mixture comprising 1-butenes and 2-butenes which does not comply with the thermodynamic equilibrium value.

11. The butene isomerization process according to claim 1, characterized in that the 2-butene-containing stream has a mass concentration of 1-butene lower than 4% and a mass concentration of 2-butene higher than 45%.

12. The butene isomerization process of claim 1, wherein the mass concentration of 1, 3-butadiene in the 2-butene-containing stream is less than 30 ppm.