阅读说明：本技术 一种固体催化剂催化精馏选择性制备二元醇单叔丁醚的方法 (Method for selectively preparing dihydric alcohol mono-tertiary butyl ether by catalytic distillation of solid catalyst ) 是由 王荷芳 蒋慧 李小保 孙沛东 王翠 邵凯 马笑飞 于 2021-10-08 设计创作，主要内容包括：本发明为一种固体催化剂催化精馏选择性制备二元醇单叔丁醚的方法。该方法选取固体酸为催化剂,以二元醇和醚化试剂为原料,加入C8抑制剂,通过催化精馏装置,实现选择性制备二元醇单叔丁醚。本发明在反应过程中及时移走产物二元醇单叔丁醚,同时将二元醇双叔丁基醚添加至反应物中,抑制了副产物二元醇双叔丁基醚的产生,提高了选择性,大大降低了分离难度,降低了能耗,减少设备投资。(The invention relates to a method for selectively preparing dihydric alcohol mono-tertiary butyl ether by catalytic distillation of a solid catalyst. The method selects solid acid as a catalyst, takes dihydric alcohol and an etherification reagent as raw materials, adds a C8 inhibitor, and realizes the selective preparation of the dihydric alcohol mono-tertiary butyl ether by a catalytic rectification device. The method removes the product dihydric alcohol mono-tertiary butyl ether in time in the reaction process, and simultaneously adds the dihydric alcohol di-tertiary butyl ether into the reactant, thereby inhibiting the generation of the byproduct dihydric alcohol di-tertiary butyl ether, improving the selectivity, greatly reducing the separation difficulty, reducing the energy consumption and reducing the equipment investment.)

1. A method for selectively preparing dihydric alcohol mono-tertiary butyl ether by catalytic distillation of a solid catalyst is characterized by comprising the following steps:

feeding dihydric alcohol from the upper part of a reaction section of the catalytic rectifying tower, mixing an etherification reagent with a C8 inhibitor, gasifying the mixture, then feeding the mixture into the catalytic rectifying tower from the lower part of a rectification reaction section for heterogeneous catalytic reaction, feeding a reaction product into a rectification section of the catalytic rectifying tower, and extracting a light component product from the top of the tower after separation; extracting unreacted dihydric alcohol, dihydric alcohol mono-tertiary butyl ether and dihydric alcohol di-tertiary butyl ether generated by the reaction from a tower kettle to obtain a product containing the dihydric alcohol mono-tertiary butyl ether;

the temperature of a catalyst bed layer in the reaction section of the rectifying tower is 50-200 ℃, the temperature of a tower kettle is 90-250 ℃, the temperature of a tower top is 30-100 ℃, the operating pressure of the catalytic rectifying tower is 0.1-1.8MPa, and the reflux ratio of the catalytic rectifying tower is 1-10: 1;

the molar ratio of the dihydric alcohol to the etherification reagent is 1.05-110; the mass ratio of the C8 inhibitor to the etherification reagent is 0.05-50;

the dihydric alcohol comprises dihydric alcohol containing 2-10 carbon atoms or polyglycidyl alcohol containing 4-10 carbon atoms;

the solid catalyst comprises one or more of strong acid ion exchange resin, heteropoly acid, molecular sieve and active alumina.

2. The method for selectively preparing the dihydric alcohol mono-tertiary butyl ether by catalytic distillation of the solid catalyst as claimed in claim 1, wherein the distillation tower is divided into a rectifying section, a reaction section and a stripping section; the theoretical plate number is 19-30 blocks; wherein, the rectifying section: 8-11 theoretical plates, reaction section: 7-12 theoretical plates, stripping section: 4-7 theoretical plates. The feeding position of the feeding port I is 9 th to 17 th theoretical plates (from top to bottom), the feeding temperature is 50 ℃ to 200 ℃, the feeding position of the feeding port II is 16 th to 26 th theoretical plates (from top to bottom), and the feeding temperature is 85 ℃ to 200 ℃.

3. The method for selectively preparing the mono-tertiary butyl ether of the dihydric alcohol by the catalytic distillation of the solid catalyst as claimed in claim 1, wherein the dihydric alcohol is ethylene glycol, propylene glycol, butanediol, pentanediol, diethylene glycol, triethylene glycol, dipropylene glycol or tripropylene glycol;

the etherification reagent is isobutene or MTBE;

the C8 inhibitor is one or more of tert-butyl alcohol, tert-amyl alcohol, toluene and ethylene glycol diethyl ether.

4. The method for selectively preparing the dihydric alcohol mono-tertiary butyl ether by catalytic distillation with the solid catalyst as claimed in claim 1, wherein the catalytic distillation tower is a packed tower, and the packing is corrugated plate packing.

5. The method for selectively preparing the dihydric alcohol mono-tertiary butyl ether by catalytic distillation of the solid catalyst as claimed in claim 1, wherein the particle size of the catalyst is 0.1-5 mm.

6. The solid catalyst is filled in the middle of a filler interlayer of the reaction section, and the volume ratio of the catalyst to the filler is 0.1-0.6: 1.

Technical Field

The invention relates to a synthesis process for selectively synthesizing dihydric alcohol mono-tertiary butyl ether by catalytic distillation by taking an etherification reagent and dihydric alcohol as raw materials, belonging to chemical products.

Background

The dihydric alcohol mono-tert-butyl ether is a novel environment-friendly solvent and can be used as a substitute of the isomeric dihydric alcohol mono-n-butyl ether which is harmful to human bodies. Compared with the dihydric alcohol mono-n-butyl ether, the dihydric alcohol mono-t-butyl ether has the advantages of good volatility, low toxicity, extremely low odor, low photochemical reactivity and the like, is mild in skin irritation, good in water solubility, good in dispersion stability of latex paint, compatible with most organic solvents and good in hydrophilicity, can be widely applied to many fields of paint, printing ink, dye, cleaning agent, rust remover, brake fluid, cutting fluid, electronic stripper, fiber wetting agent, plasticizer, paint remover and the like, and can also be used as an organic synthesis intermediate.

The method for synthesizing the dihydric alcohol mono-tertiary butyl ether mainly comprises the following steps:

ethylene oxide and tertiary alcohol are used as raw materials, dihydric alcohol tert-butyl ether is prepared through a ring opening reaction, the tertiary alcohol is difficult to react with the ethylene oxide, so the reaction condition is harsh (>120 ℃ and >0.4MPa), according to the report of 'ethoxylation reaction selective catalytic synthesis of ethylene glycol monobutyl ether' of Master thesis, the ethylene oxide is easy to generate ethylene oxide oligomer with higher molecular weight under the condition, and therefore, the selectivity of the dihydric alcohol mono-tert-butyl ether is low.

Etherifying reagents (isobutene and methyl tert-butyl ether (MTBE)) and dihydric alcohol are used as raw materials to synthesize dihydric alcohol mono-tert-butyl ether, and patent CN 110759817 proposes a solid catalyst, and the ethylene glycol mono-tert-butyl ether is prepared by using the MTBE and ethylene glycol as raw materials through fixed bed reaction and reactive rectification processes. The pressure of the fixed bed reactor is 0.45MPa, the reaction temperature is 65 ℃, and the molar ratio of alcohol ether is 1.1: 1. space velocity of 2.00h^-1Under the condition, the reaction liquid enters an azeotropic distillation tower for fractional distillation (the tower pressure is 0.08MPa, the reflux ratio is 4, the tower kettle is 185-190 ℃, the tower top temperature is 98.5-99 DEG)After the by-product is separated, the purity can be obtained>99.5% of ethylene glycol mono-tert-butyl ether. However, the modified ZrO in the patent₂The preparation process of the solid acid catalyst is complex, and the fixed bed process and the reactive distillation process are simultaneously used in the reaction, so that the use amount of the catalyst is increased, the investment on equipment is increased, reactants are not completely reacted, and the energy consumption for separation is higher.

Patent CN 108840789 reports that MTBE is synthesized into ethylene glycol tert-butyl ether under the reaction conditions of 55 ℃ and 1.0MPa alcohol ether molar ratio of 2.5:1 by using a strongly acidic ion exchange resin catalyst in a fixed bed tubular reactor, thereby simplifying the reaction process, the conversion rate of MTBE is only 55.33%, and the selectivity of ethylene glycol tert-butyl ether is 92.75%. The process route has the advantages of mild reaction conditions, simple flow, convenient product separation, low cost and the like. However, the reaction is limited by thermodynamic equilibrium, the single-pass conversion is low, and the selectivity to glycol mono-tert-butyl ether is low.

Patent CN 106397137 proposes a method for synthesizing dihydric alcohol mono-tertiary butyl ether by using dihydric alcohol and isobutene as raw materials and utilizing a catalytic rectification process, wherein gaseous isobutene and liquid-phase dihydric alcohol are introduced into a catalyst bed layer in the middle of a reactor, the generated dihydric alcohol mono-tertiary butyl ether is evaporated out of the bed layer under the stripping action of the gaseous isobutene, the phenomenon that the dihydric alcohol mono-tertiary butyl ether continuously reacts with the isobutene to generate ethylene glycol di-tertiary butyl ether can be avoided, the dihydric alcohol mono-tertiary butyl ether is separated at the upper part of the reactor, the unreacted isobutene and the dihydric alcohol are extracted from the top of the tower or a side line after the condensation at the top of the tower, and the unreacted isobutene and the unreacted dihydric alcohol are respectively extracted from the top of the tower and the bottom of the tower and then are recycled to an inlet. However, this patent is only applicable to the reaction of dihydric alcohol and isobutylene, and a large amount of C8 byproduct is generated during the reaction.

The problems of low single-pass conversion rate, high energy consumption, large equipment investment and the like of a reaction process exist due to the generation of a large amount of dihydric alcohol double-tert-butyl ether in the synthesis process of the dihydric alcohol single-tert-butyl ether.

Disclosure of Invention

The invention aims to provide a method for selectively preparing dihydric alcohol mono-tertiary butyl ether by catalytic distillation with a solid catalyst aiming at the defects in the prior art. The method selects solid acid as a catalyst, takes dihydric alcohol and an etherification reagent as raw materials, adds a C8 inhibitor, and realizes the selective preparation of the dihydric alcohol mono-tertiary butyl ether by a catalytic rectification device. The method removes the product dihydric alcohol mono-tertiary butyl ether in time in the reaction process, and simultaneously adds the dihydric alcohol di-tertiary butyl ether into the reactant, thereby inhibiting the generation of the byproduct dihydric alcohol di-tertiary butyl ether, improving the selectivity, greatly reducing the separation difficulty, reducing the energy consumption and reducing the equipment investment.

The technical scheme of the invention is as follows:

a method for selectively preparing dihydric alcohol mono-tertiary butyl ether by catalytic distillation of a solid catalyst comprises the following steps:

feeding dihydric alcohol from the upper part of a reaction section of a catalytic rectifying tower, mixing an etherifying reagent with a C8 inhibitor, gasifying the mixture, then feeding the mixture into a catalytic rectifying filler from the lower part of the reaction section for carrying out heterogeneous catalytic reaction, feeding a product into a rectifying section of the catalytic rectifying tower, separating and then extracting a light component product from the top of the tower, and extracting unreacted dihydric alcohol, dihydric alcohol mono-tert-butyl ether and dihydric alcohol di-tert-butyl ether generated by reaction from a tower kettle to obtain a product containing the dihydric alcohol mono-tert-butyl ether; after separation, the unreacted dihydric alcohol and the generated dihydric alcohol bis-tert-butyl ether are returned to the feeding position of the reaction rectifying tower for recycling.

The temperature of a catalyst bed layer in the reaction section of the rectifying tower is 50-200 ℃, the temperature of a tower kettle is 90-250 ℃, the temperature of a tower top is 30-100 ℃, the operating pressure of the catalytic rectifying tower is 0.1-1.8Mpa, and the reflux ratio R of the catalytic rectifying tower is 1-10: 1.

The rectifying tower is divided into a rectifying section, a reaction section and a stripping section; the theoretical plate number is 19-30 blocks; wherein, the rectifying section: 8-11 theoretical plates, reaction section: 7-12 theoretical plates, stripping section: 4-7 theoretical plates. The feeding position of the feeding port I is 9 th to 17 th theoretical plates (from top to bottom), the feeding temperature is 50 ℃ to 200 ℃, the feeding position of the feeding port II is 16 th to 26 th theoretical plates (from top to bottom), and the feeding temperature is 85 ℃ to 200 ℃.

Wherein, the filler of the rectifying section is loaded with a solid catalyst;

the dihydric alcohol comprises dihydric alcohol containing 2-10 carbon atoms or polyhydric dihydric alcohol containing 4-10 carbon atoms, preferably one of ethylene glycol, propylene glycol, butanediol, pentanediol, diethylene glycol, triethylene glycol, dipropylene glycol or tripropylene glycol; the molar ratio of the dihydric alcohol to the etherification reagent in the reaction system is 1.05: 110;

the etherification reagent comprises one of isobutene and MTBE.

The C8 inhibitor is one or more of tert-butyl alcohol, tert-amyl alcohol, toluene and ethylene glycol diethyl ether; the mass ratio of the C8 inhibitor to the etherification reagent in the reaction system is 0.05-50.

In the present invention, the C8 inhibitor can inhibit the generation of C8 by-products such as diisobutylene and can be used as a cosolvent to allow the etherification reagent and the dihydric alcohol to fully contact in the rectification section.

The solid catalyst comprises one or more of strong acid ion exchange resin, heteropoly acid, molecular sieve and active alumina. The particle size of the catalyst is 0.1-5 mm.

The solid catalyst is filled in the middle of a filler interlayer of the reaction section, and the volume ratio of the catalyst to the filler is 0.1-0.6: 1.

The invention has the beneficial effects that:

the invention provides a catalytic distillation synthesis method of dihydric alcohol mono-tertiary butyl ether, wherein the product dihydric alcohol mono-tertiary butyl ether is removed in time, and the separated dihydric alcohol di-tertiary butyl ether is returned to the feeding material, thereby reducing the generation of the byproduct dihydric alcohol di-tertiary butyl ether, improving the selectivity, reducing the material consumption and the separation energy consumption, and reducing the equipment investment. The conversion rate of the reaction raw material is up to 85 percent, and the selectivity of the reaction raw material to the dihydric alcohol mono-tertiary butyl ether is up to 99 percent.

The addition of the C8 inhibitor can inhibit the generation of C8 byproducts such as diisobutylene and the like, solve the problems of immiscible etherification reagent and glycol and low liquid-liquid phase mass transfer efficiency, reduce the reaction pressure and reaction temperature and ensure that the reaction can be carried out under mild conditions.

Drawings

FIG. 1 is a schematic diagram of a catalytic distillation reaction apparatus.

Wherein, 1-feeding inlet I, 2-feeding inlet II, 3-preheating inlet I, 4-preheating inlet II, 5-raw material mixing tank, 6-tower top, 7-rectifying section, 8-catalytic reaction section, 9-stripping section and 10-tower kettle.

Detailed Description

The following examples will further illustrate the process provided by the present invention but the invention is not limited to the examples listed but also includes any other known variations within the scope of the invention as claimed.

The reactor is a reaction rectifying tower and comprises a rectifying section, a reaction section and a stripping section, wherein the material is 316L, the inner diameter is 1600mm, the height of structural packing of the reaction section is 10m, the height of the rectifying section is 7m, and the height of the stripping section is 4 m. The rectifying tower is a packed tower, and the structural form can be divided into (from top to bottom): a rectification section: 9 theoretical plates, reaction section: 12 theoretical plates, stripping section: 5 theoretical plates, for a total of 26 theoretical plates.

The preferable material of the filler is CY700 wire mesh corrugated plate filler.

The solid catalyst comprises one or more of strong acid ion exchange resin, heteropoly acid, molecular sieve and active alumina.

The catalyst and the corrugated plate filler are mixed and stirred according to the volume ratio of 0.3:1, so that the catalyst is uniformly distributed in the pore diameter of the corrugated plate filler, and then the catalyst is loaded into a reaction section (from top to bottom, 10 th to 21 th theoretical plate) of a rectifying tower.

The reactor of the present invention is combined to produce glycol mono-tertiary-butyl ether in the following connection relationship:

feeding the dihydric alcohol from a feeding hole I, passing through a preheater I, and entering the upper end of the reaction section; feeding an etherification reagent and a C8 inhibitor from a feeding hole II, heating and gasifying the mixture by a preheater II, fully mixing the mixture in a raw material mixing tank, and feeding the mixture into the lower end of the reaction section; the mixed gas of the etherification reagent and the C8 inhibitor and the dihydric alcohol are in full contact reaction in a catalytic reaction section of the catalytic rectification tower, the unreacted etherification reagent and the C8 inhibitor enter a rectification section through a rising steam pipeline, and flow back to the top of the tower through a reflux pipeline to be extracted; liquid in the tower flows into the stripping section through the stripping section and flows out of the device from the tower kettle; the material flow extracted from the tower kettle comprises a reaction product of dihydric alcohol mono-tertiary butyl ether, excessive dihydric alcohol and a small amount of byproducts; the tower kettle reflux material flow comprises partial liquid vaporization, excessive dihydric alcohol separated by subsequent rectification reflows to the top of the catalytic rectification tower and enters a catalytic reaction section for continuous reaction.

The gas chromatographic analysis of the product was as follows: KB-1(30 × 0.32 × 0.50) capillary chromatography column, FID hydrogen flame detector; the initial temperature is 80 ℃, the temperature is kept for 1min, the final temperature is 250 ℃, the temperature is kept for 20min, and the heating rate is 8 ℃ min^-1(ii) a The temperature of the detector is 250 ℃, the temperature of the vaporization chamber is 250 ℃, and the flow rate of the carrier gas is 30 mL/min^-1The sample size was 0.2. mu.L, and the split ratio was 1/30.

Example 1

Preparation of ethylene glycol mono-tert-butyl ether.

The catalyst filled in the catalytic rectification structure filler of the reaction section is beta molecular sieve, and the particle size of the catalyst is 0.4-0.8 mm. The catalytic rectifying tower is operated under 0.6MPa, ethylene glycol is fed from a 10 th theoretical plate of structural filler, the feeding temperature is 100 ℃, MTBE and tertiary butanol are uniformly mixed and then enter the structural filler from a 20 th theoretical plate of the structural filler of the catalytic rectifying tower, the feeding temperature is 100 ℃, the ethylene glycol, the MTBE and the tertiary butanol react at the catalytic rectifying filler, the temperature of the structural filler is maintained at 100 ℃, the temperature of the top of the tower is 30 ℃, and the temperature of the bottom of the tower is 120 ℃.

The ethylene glycol flow rate of the catalytic distillation tower is 1000kg/h, the mass ratio of tert-butyl alcohol to MTBE is 2.238:1, the flow rate of a mixed liquid of MTBE and tert-butyl alcohol is 1839kg/h, the molar ratio of ethylene glycol to MTBE is 2.5:1, and the reflux ratio is 10:1, gas phase analysis is carried out on products at the top and the bottom of the tower, the content is shown in Table 1, the yield content of ethylene glycol mono-tert-butyl ether at the bottom of the tower is 90.0%, the selectivity is 99.9%, and the purity of the ethylene glycol mono-tert-butyl ether product separated by subsequent distillation is 99.5%.

TABLE 1

Example 2

Preparation of ethylene glycol mono-tert-butyl ether

The catalyst D006 etherified resin catalyst is filled in the catalytic rectification structure packing of the reaction section, and the particle size of the catalyst is 0.8-2 mm. The catalytic rectification tower is operated under 1.4MPa, ethylene glycol is fed from the 10 th theoretical plate of the catalytic rectification packing, the feeding temperature is 110 ℃, tert-butyl alcohol is evenly mixed with isobutene after gasification, the ethylene glycol enters the catalytic rectification packing from the 21 st theoretical plate of the catalytic rectification packing, the feeding temperature is 90 ℃, the ethylene glycol, the isobutene and the tert-butyl alcohol are mixed at the catalytic rectification packing, the temperature of the structural packing is maintained at 110 ℃, the temperature of the top of the tower is 35 ℃, and the temperature of the bottom of the tower is 140 ℃.

The ethylene glycol flow rate of the catalytic distillation tower is 1200kg/h, the mass ratio of the tertiary butyl alcohol to the isobutene is 10:1, the flow rate of the mixed gas of the tertiary butyl alcohol and the isobutene is 115.5kg/h, the molar ratio of the ethylene glycol to the isobutene is 103:1, and the reflux ratio is 10:1, the content of the products at the tower top and the tower bottom is shown in table 2 after gas phase analysis, the yield content of the ethylene glycol mono-tertiary-butyl ether at the tower bottom is 90.0%, the selectivity is 99.9%, and the purity of the ethylene glycol mono-tertiary-butyl ether product separated by subsequent distillation is 99.5%.

TABLE 2

Example 3

Preparation of propylene glycol mono-tert-butyl ether

The catalyst filled in the catalytic rectification structure filler of the reaction section is macroporous strong-acid styrene cation exchange resin, and the particle size of the catalyst is 0.8-2 mm. The catalytic rectification tower is operated under 1.0MPa, propylene glycol is fed from the 11 th theoretical plate of the catalytic rectification packing at the feeding temperature of 110 ℃, tertiary butanol is gasified and then uniformly mixed with isobutene, the feeding temperature is 100 ℃, propylene glycol, isobutene and tertiary butanol enter the catalytic rectification packing from the 20 th theoretical plate of the catalytic rectification packing and are mixed at the catalytic rectification packing, the temperature of the structural packing is maintained at 110 ℃, the temperature of the top of the tower is 25 ℃, and the temperature of the bottom of the tower is 130 ℃.

The flow rate of propylene glycol at the inlet of the catalytic distillation tower is 600kg/h, the mass ratio of tert-butyl alcohol to isobutylene is 10:1, the flow rate of a mixed gas of tert-butyl alcohol and isobutylene is 115.5kg/h, the molar ratio of propylene glycol to isobutylene is 42:1, and the reflux ratio is 10:1, the content of a tower bottom product is shown in table 3 through gas phase analysis, the yield content of propylene glycol mono-tert-butyl ether at the tower bottom is 91.0%, the selectivity is 99.9%, and the purity of the propylene glycol mono-tert-butyl ether product separated through subsequent distillation is 99.7%.

TABLE 3

Example 4

And (3) preparing diethylene glycol mono-tert-butyl ether.

The catalyst filled in the catalytic distillation structure packing of the reaction section is H-ZSM-5 molecular sieve, and the particle size of the catalyst is 0.4-0.8 mm. The catalytic rectification tower is operated under 0.6MPa, diethylene glycol is fed from the 11 th theoretical plate of the catalytic rectification packing at the feeding temperature of 90 ℃, MTBE and tert-butyl alcohol are uniformly mixed and then enter the catalytic rectification packing from the 21 st theoretical plate of the catalytic rectification packing in a gaseous state through the catalytic rectification tower, the feeding temperature is 90 ℃, the diethylene glycol, the MTBE and the tert-butyl alcohol are mixed at the catalytic rectification packing, the temperature of the structural packing is maintained at 90 ℃, the temperature of the top of the tower is 20 ℃, and the temperature of the bottom of the tower is 120 ℃. .

The flow rate of diethylene glycol at the inlet of the catalytic distillation tower is 1500kg/h, the mass ratio of tert-butyl alcohol to MTBE is 2.238:1, the flow rate of a mixed solution of MTBE and tert-butyl alcohol is 1839kg/h, the molar ratio of diethylene glycol to MTBE is 2.2:1, and the reflux ratio is 10:1, the content of the product at the bottom of the tower is shown in Table 4 by gas phase analysis, the yield content of diethylene glycol mono-tert-butyl ether at the bottom of the tower is 89.9%, the selectivity is 99.95%, and the purity of the diethylene glycol mono-tert-butyl ether product separated by subsequent distillation is 99.8%.

TABLE 4

The invention is not the best known technology.