CN102787144B - Process for producing acetone and butanol by coupling biomass fermentation and pervaporation membrane - Google Patents

Abstract

The present invention relates to a process for producing acetone-butanol through coupling of biomass fermentation and pervaporation membrane, in particular to a production process of coupling pervaporation membrane with ABE fermentation process, separating ABE in situ online, and using an extraction tower to obtain anhydrous solvent . The fermentation liquid in the fermenter is extracted, and the concentrated liquid is obtained by preferentially permeating the alcohol membrane. The concentrated liquid is sent to the extraction tower, where it is divided into an organic phase and an aqueous phase. After the aqueous phase is pumped into the aqueous phase storage tank, the organic phase does not pass through the mash. The tower directly enters the Yiding tower and the subsequent rectification tower group to obtain anhydrous butanol, acetone and ethanol. The water phase in the water phase storage tank passes through the alcohol membrane module first through pervaporation, and the permeate is pumped into the extraction tower, and so on. The invention couples the fermentation process with the pervaporation technology, and adds an extraction tower after the pervaporation module, which not only reduces the inhibitory effect of butanol in the fermentation process, but also saves energy consumption in the separation process, and improves the efficiency of producing butanol by biomass fermentation Competitiveness.

Description

A process for producing acetone-butanol coupled with biomass fermentation-pervaporation membrane

field of invention

The present invention relates to a process for producing acetone butanol through coupling of biomass fermentation and pervaporation membrane, in particular to a fermentation process of coupling fermentation and pervaporation to produce ABE, separating ABE on-line and in situ, and using pervaporation permeation membrane and extraction tower A process for obtaining anhydrous solvents.

Background technique

With the increasing shortage of oil resources in the world, countries all over the world are actively looking for the development and utilization of renewable resources. As an important renewable energy source, biofuel has attracted the attention of various countries. It is estimated that the proportion of biofuel will increase to 30% by 2020, and the total demand will reach 87 billion gallons.

However, at present, butanol is mainly produced by propylene synthesis method, which uses propylene in petroleum as raw material to prepare butanol products. With the depletion of petroleum resources, the development of new butanol production methods using renewable biomass resources has become a hot spot of international concern. Fermentation is recognized as a butanol production process that is expected to replace propylene synthesis. However, the two main problems encountered in the production of butanol by fermentation are the feedback inhibition of fermentation products and the high energy consumption of separation and concentration. Feedback inhibition means that after the concentration of certain metabolites reaches a certain range, since the target product has a non-competitive inhibitory effect on the growth of microorganisms, the fermentation reaction is difficult to proceed normally, the target product no longer increases, and the concentration of the target product in the product fermentation broth is too high. low phenomenon. Because of this, the concentration of ABE in butanol fermentation broth is only 1-2% (the products of butanol fermentation are usually butanol, acetone and ethanol, the three are abbreviated as ABE, and the ratio of butanol, acetone and ethanol is 6% :3:1). Such a low concentration of butanol results in high energy consumption for subsequent product separation and concentration. According to reports, the energy consumption required to concentrate the butanol fermentation broth by the traditional distillation method is higher than the combustion heat energy of butanol itself. It accounts for 50% of the entire distillation energy consumption. For this reason, butanol has been produced synthetically from propylene for many years. It can be seen that the development of new and effective separation technology to solve the problems of product feedback inhibition and high energy consumption of product concentration in the process of fermentation and production of biofuels is the key to realizing the industrial production of biofuel butanol, and it is of great importance to improve the fermentation production of butanol. The technical economy of alcohol is of great significance.

Currently, there are 201010136813.5 and 201010162856.0 patents for the in-situ separation of acetone, butanol and ethanol using pervaporation coupling. In patent 201010136813.5, a microfiltration membrane separator is selectively installed in front of the pervaporation membrane to intercept the suspended solids in microbial cells and fermentation broth, thereby reducing the pollution of the pervaporation membrane and improving the separation efficiency. Patent 201010162856.0, before the fermented mash is sent from the previous fermenter to the next fermenter, the liquid phase part of the fermented mash is first separated from the butanol through the pervaporation membrane separation device, and the fermented mash after the butanol separation is sent to the next fermenter. A fermenter. There are literatures at home and abroad that use fermentation-pervaporation coupling process to reduce inhibition and increase butanol yield, such as Heitmann et al. (2012), Wouter et al. (2012) use ionic liquid supported liquid membrane and PDMS membrane to separate fermentation broth solvent in. But none of these reports involves the application of the phase separation phenomenon of acetone butanol solvent. The invention utilizes the phase separation characteristic of the ABE concentrated liquid, adds an extraction tower after the pervaporation process, and the high-concentration solvent in the extraction tower undergoes phase separation. Wherein the concentration of the organic phase solvent can reach the concentration (500g/L) after the beer tower is concentrated, so that the beer tower is omitted in the subsequent rectification process, and the extraction tower does not increase energy consumption, so compared to CN101805754A and CN101851641A, this The process reduces energy and water consumption, resulting in anhydrous solvents.

Contents of the invention

The object of the present invention is to provide a process for producing acetone-butanol using fermentation pervaporation coupling technology, which removes the inhibitory effect of ABE on bacteria in the fermentation process and improves the yield of acetone-butanol.

Another object of the present invention is to provide a method for obtaining high-concentration acetone, butanol, and ethanol by using a pervaporation and extraction tower, which reduces subsequent distillation steps, reduces energy consumption, and realizes energy saving and emission reduction.

The invention provides a process for producing anhydrous solvent coupled with continuous fermentation and pervaporation membrane separation, which is characterized in that the process is as follows:

(1) Using pretreated biomass as a fermentation substrate, inoculate butanol acetone ethanol production strains for fermentation;

(2) The fermentation liquid in the fermenter is pumped into the pervaporation preferential permeation membrane separator, the permeate is collected by the condenser to obtain the concentrated liquid of acetone, butanol and ethanol, and the retained liquid is returned to the fermenter;

(3) The permeate of acetone, butanol and ethanol is pumped into the extraction tower, and the permeate is divided into an organic phase and an aqueous phase in the extraction tower;

(4) The above-mentioned water phase is pumped into the water-phase storage tank, and the above-mentioned organic phase directly enters the Yiding tower and the subsequent rectification tower group without passing through the mash tower, so as to realize the removal of a small amount of water in the organic phase and obtain anhydrous acetone, butane Alcohol and ethanol; the water phase in the water phase storage tank passes through the pervaporation preferentially through the alcohol membrane separator to realize the concentration of a small amount of acetone, butanol and ethanol mixture in the water phase, and then enters the extraction tower for subsequent operations.

The pervaporation preferential alcohol permeation membrane separator of the present invention is composed of one or more pervaporation preferential alcohol permeation membrane separators, and the permeation side of each unit pervaporation preferential alcohol permeation membrane separator is connected in series or parallel to the vacuum pump through pipelines Main pipeline.

The pervaporation preferential alcohol permeation membrane of the present invention is an organic membrane, an inorganic membrane or an organic-inorganic hybrid membrane; the membrane module is in the form of a coil, a tube, a plate-and-frame or a hollow fiber.

The material of the organic-inorganic hybrid membrane of the present invention is one of PDMS-Silicalite-1, PDMS-ZSM-5 or PTMSP-Silicalite; the material of the organic membrane is silicone rubber, polytrimethylsilapropyne, Polypropylene, polyvinylidene fluoride or polytetrafluoroethylene; the material of the inorganic membrane can be Silicalite-1 or ZSM-5.

The extraction tower of the present invention is one of a spray extraction tower, a sieve tray tower, a rotating disk tower and a pulse tower.

The biomass of the present invention can be lignocellulose (such as wheat straw, corn straw, bagasse and other crop straws, grasses, and wood chips of broad-leaved trees or conifers), and can also be starchy substances (such as corn, cassava, etc.) , sweet potato, potato, kudzu root or one or both), or sugar raw materials (such as molasses, sorghum juice). The pretreatment method of lignocellulose can be conventional chemical pretreatment such as dilute acid or physical and chemical pretreatment such as steam explosion. The hydrolysis temperature of lignocellulose is 45-50°C, and the temperature of acetone-butanol fermentation is 37-40°C. Preferred acetobutylicum fermenting microorganisms are C.acetobutylicum ATCC824, C.butylicum23592, C.acetobutylicum170, C.acetobutylicum P260, C.beijerinckii ATCC55025.

A process for producing acetone butanol using a fermentation pervaporation coupling process provided by the present invention organically combines fermentation, pervaporation preferential permeation membrane separator and rectification process, realizes the in-situ separation of fermentation product acetone butanol ethanol, reduces The inhibitory effect of acetone, butanol, and ethanol on fermenting microorganisms is improved, and the butanol fermentation intensity is improved; at the same time, an extraction tower is set after the pervaporation preferential alcohol permeation membrane separator, which fully and effectively utilizes the pervaporation preferential alcohol permeation membrane separator. The subsequent phase separation of the permeate reduces the cost of subsequent solvent separation. The process provided by the invention tightly couples the fermentation process of glucose acetone butanol in the hydrolyzate with the separation process of the pervaporation membrane, saves energy and water consumption in the production process, and reduces the production cost of producing fuel butanol from biomass.

Description of drawings

Fig. 1 is the technological process schematic diagram of acetone-butanol scheme one produced by fermentation pervaporation rectification integrated process;

reference sign

1. Feed tank 2. Feed pump 3. Fermentation tank 4. Feed pump 5. Pervaporation priority permeation membrane module 6. Condenser 7. Pressure gauge 8. Vacuum pump 9. Feed pump 10. Extraction tower 11. Feed pump 12. Valve 13. Water phase storage tank 14. Feed pump 15. Pervaporation priority permeation membrane module 16. Condenser 17. Pressure gauge 18. Vacuum pump 19. Feed pump 20. Yiding tower

Detailed ways

The present invention will be further described below in conjunction with the embodiments, and the protection scope of the subject matter involved in the present invention is not limited to these embodiments.

Example 1 A process for producing acetone butanol by a corn stalk fermentation-pervaporation coupling process

Corn stalks are treated with steam explosion, acid hydrolysis, and enzyme hydrolysis to make a slurry into the feed tank 1, turn on the feed pump 2 and enter the fermentation tank 3, and ferment at 37°C for 72 hours after being inoculated with microorganisms. When the solvent concentration is detected to reach 18g/L, the feed pump 4 is turned on, and the fermentation liquid is transported into the pervaporation-preferential alcohol-permeable membrane module 5. The pervaporation module is composed of two plate-and-frame pervaporation-preferential alcohol-permeable membrane separators connected in series. The pervaporation membrane used is an organic-inorganic hybrid membrane (PDMS-Silicalite-1). Simultaneously, open vacuum pump 8, pressure gauge 7 vacuum degrees maintain on 500Pa, and permeate is collected by condenser 6, and the acetone, butanol and ethanol total concentration of collecting gained reaches 150g/L, and the feed liquid intercepted returns in fermentor 3; After 12 hours of coupling separation, the coupling separation is suspended, and the straw hydrolyzed sugar liquid with the same volume as the permeate obtained from the pervaporation membrane separation is fed into the fermenter from the feeding tank 1, and the fermentation is continued. Open feed pump 9 simultaneously, the permeate that collects in condenser 6 enters extraction tower 10, and extraction tower is a spray extraction tower, is divided into organic phase and water phase in extraction tower; In the extraction tower, water phase concentration is about 100g /L, by feed pump 11, open valve 12 and enter 13 passages of water phase storage tank; The organic phase concentration in the extraction tower reaches 500g/L, by feed pump 11, open valve 12 and enter 20 passages of a butadiene tower, obtain no Water butanol, acetone and ethanol; the water phase in the water phase storage tank 13 is input into the pervaporation preferential alcohol permeation membrane module 15 through the feed pump 14, the vacuum pump 18 is turned on, the pressure gauge pressure is 500pa, and all the organic phases of the extraction tower enter a The tower 20, the condenser 16 collects the permeate and enters the extraction tower 12 through the feed pump 19, so as to circulate, and finally obtain anhydrous butanol, acetone and ethanol. After 12 hours of coupling separation, the coupling separation is suspended, and the straw hydrolyzed sugar liquid with the same volume as the permeate obtained from the pervaporation membrane separation is fed into the fermenter from the feeding tank 1, and the fermentation is continued. When the concentration of the total solvent in the fermenter 2 reaches 18g/L, the vacuum pump is turned on, and the coupling separation is performed again, and the permeate enters the condenser to be collected, and thus circulates 10 times.

This example realizes the production of acetone butanol by semi-continuous fermentation of corn stalk hydrolyzed sugar solution, which not only greatly reduces the inhibitory effect of the acetone butanol solvent produced by fermentation on microbial cells, but also adds an extraction tower after pervaporation preferentially passes through the alcohol membrane module. , making full use of the phase separation properties of the pervaporation-preferential permeation membrane permeate, effectively reducing the energy consumption of the concentration process, compared with the traditional batch fermentation-distillation process, the production intensity of butanol is increased, and the omission of the mash tower can save Distillation energy consumption.

Embodiment 2 A kind of technology of corn flour fermentation-pervaporation coupled process to produce acetone butanol

Prepare the medium with corn flour as raw material, cook and gelatinize at 121°C for 90 minutes to obtain the corn flour medium, enter the feed tank 1, turn on the feed pump 2 and enter the fermenter 3, inoculate the microorganisms and ferment at 37°C for 60 hours, when When the total solvent concentration in the liquid phase in the tank is detected to reach 20g/L, the feed pump 4 is turned on, and the fermentation liquid is transported into the pervaporation preferential alcohol permeation membrane module 5, which is composed of a hollow fiber pervaporation preferential alcohol permeation membrane separator , the selected pervaporation membrane is the inorganic membrane Silicalite-1 or ZSM-5. Simultaneously, open vacuum pump 8, pressure gauge 7 vacuum degrees maintain on 500Pa, and permeate is collected by condenser 6, and the acetone, butanol and ethanol total concentration of collecting gained reaches 400g/L, and the feed liquid intercepted returns in fermentor 3; After 12 hours of separation, the pervaporation separation was suspended, and the straw hydrolyzed sugar solution with the same volume as the permeate obtained from the pervaporation membrane separation was fed into the fermenter from the feeding tank 1, and the fermentation was continued. Open feed pump 9 simultaneously, the permeate that collects in condenser 6 enters extraction tower 10, and extraction tower is a sieve plate tower, is divided into organic phase and water phase in extraction tower; L, through the feed pump 11, open the valve 12 to enter the water phase storage tank 13 passage; the organic phase concentration in the extraction tower reaches 700g/L, through the feed pump 11, open the valve 12 to enter the 13 passage of the butan tower to obtain anhydrous Butanol, acetone and ethanol; the water phase in the water phase storage tank 13 is input into the pervaporation preferential alcohol-permeable membrane module 15 through the feed pump 14, the vacuum pump 18 is turned on, the pressure gauge pressure is 500pa, and the organic phase of the extraction tower is all entered into the one-butan tower 20. The permeate collected by the condenser 16 enters the extraction tower 12 through the feed pump 19, and circulates in this way to finally obtain anhydrous butanol, acetone and ethanol. After 12 hours of coupling and separation, the coupling and separation is suspended, and the straw hydrolyzed sugar solution with the same volume as the permeate obtained from the pervaporation membrane separation is fed from the feeding tank 1 to the fermenter, and the fermentation is continued. When the concentration of the total solvent in the fermenter 2 reaches 20g/L, the vacuum pump is turned on, and the coupling separation is performed again, and the permeate enters the condenser to be collected, and the cycle is repeated 10 times.

This example realizes the semi-continuous fermentation of corn flour to produce acetone butanol, which not only greatly reduces the inhibitory effect of the acetone butanol solvent produced by fermentation on microbial cells, but also makes full use of the The phase separation property of high-concentration permeate can effectively reduce the energy consumption of the concentration process, and increase the production intensity of butanol compared with the traditional batch fermentation-distillation process.

Example 3 A process for producing acetone-butanol by a continuous fermentation-pervaporation coupling process of corn stalks

Corn stalks are treated with steam explosion, acid hydrolysis, and enzyme hydrolysis to make a slurry into the feed tank 1, turn on the feed pump 2 and enter the fermentation tank 3, and ferment at 37°C for 20 hours after being inoculated with microorganisms. When the solvent concentration is detected to reach 5g/L, the feed pump 4 is turned on, and the fermentation broth is transported into the pervaporation-preferential alcohol-permeable membrane module 5. The membrane module is composed of two roll-type pervaporation-preferred alcohol-permeable membrane separators connected in parallel. The membrane is a polyvinylidene fluoride organic membrane. Simultaneously, open vacuum pump 8, pressure gauge 7 vacuum degrees maintain on 500Pa, and the permeate that collects in condenser 6 enters extraction tower 10, and extraction tower is a rotating disk tower, is divided into organic phase and water phase in extraction tower; The concentration of the aqueous phase is about 80g/L, through the feed pump 11, open the valve 12 to enter the water phase storage tank 13 passage; the organic phase concentration in the extraction tower reaches 500g/L, through the feed pump 11, open the valve 12 to enter a small The passage of tower 20 directly enters the Yiding tower to obtain anhydrous butanol, acetone and ethanol; the water phase in the water phase storage tank 13 is input into the pervaporation preferential alcohol permeation membrane module 15 through the feed pump 14, and the vacuum pump 18 is turned on, and the pressure gauge The pressure is 500pa, and all the organic phases of the extraction tower enter the one-butanol tower 20, the permeate collected by the condenser 16 enters the extraction tower 12 through the feed pump 19, and circulates like this to finally obtain anhydrous butanol, acetone and ethanol.

This example realizes the continuous fermentation of corn stalks to produce acetone butanol, which not only greatly reduces the inhibitory effect of the acetone butanol solvent produced by fermentation on microbial cells, but also makes full use of the permeation efficiency due to the addition of an extraction tower after pervaporation preferentially permeates the alcohol membrane. The phase-separation property of vaporization-preferred permeation membrane permeate can effectively reduce the energy consumption of the concentration process, and the production intensity of butanol is also improved compared with the traditional batch fermentation-distillation process.

Embodiment 4 A kind of technology of corn flour continuous fermentation-pervaporation coupled process to produce acetone butanol

Use corn flour as raw material to prepare medium, cook and gelatinize at 121°C for 90 minutes to obtain corn flour medium, enter feeding tank 1, turn on feed pump 2 and enter fermenter 3, inoculate microorganisms and ferment at 37°C for 20 hours, when When the total solvent concentration in the liquid phase in the tank is detected to reach 5g/L, the feed pump 4 is turned on, and the fermentation liquid is transported into the pervaporation-preferential alcohol-permeable membrane module 5, which consists of three tubular pervaporation-preferential alcohol-permeable membrane separators Composition in parallel, the pervaporation membrane used is organic membrane polypropylene or organic-inorganic hybrid membrane PTMSP-Silicalite-1. Simultaneously, open vacuum pump 8, pressure gauge 7 vacuum degrees maintain on 500Pa, permeate is collected by condenser 6, and the acetone, butanol and ethanol total concentration of collecting gained reaches 200g/L, and the feed liquid intercepted returns in fermentor 3; Simultaneously The straw hydrolyzed sugar solution with the same volume as the permeate obtained from pervaporation membrane separation is fed into the fermenter from the feeding tank 1 to continue fermentation. Simultaneously open the feed pump 9, the permeate collected in the condenser 6 enters the extraction tower 10, the extraction tower is a pulse tower, and is divided into an organic phase and an aqueous phase in the extraction tower; the concentration of the aqueous phase in the extraction tower is about 100g/L , through the feed pump 11, open the valve 12 to enter the water phase storage tank 13 passages; the organic phase concentration in the extraction tower reaches 520g/L, and through the feed pump 11, open the valve 12 to enter the 20 passages of the Ding tower to obtain anhydrous D Alcohol, acetone and ethanol; the water phase in the water phase storage tank 13 is input into the pervaporation preferentially permeating the alcohol membrane module 15 through the feed pump 14, the vacuum pump 18 is turned on, the pressure gauge pressure is 500pa, and the organic phase of the extraction tower enters the ethanol tower 20 , the condenser 16 collects the permeate and enters the extraction tower 12 through the feed pump 19, so as to circulate, and finally obtain anhydrous butanol, acetone and ethanol.

This example realizes the continuous fermentation of corn flour to produce acetone butanol, which not only greatly reduces the inhibitory effect of the acetone butanol solvent produced by fermentation on microbial cells, but also makes full use of the permeation efficiency due to the addition of an extraction tower after pervaporation preferentially permeates the alcohol membrane. Vaporization preferentially penetrates the phase separation property of the permeate of the alcohol membrane, omits the energy-intensive mash tower, effectively reduces the energy consumption of the concentration process, and improves the production intensity of butanol compared with the traditional batch fermentation-distillation process.

Claims (8)

1. the technique that biomass ferment-acetone-butanol is produced in the infiltrating and vaporizing membrane coupling is characterized in that, this technique key step comprises:

(1) will be through pretreated biomass as fermentation substrate, inoculation butanol acetone alcohol production bacterial classification ferments;

(2) fermented liquid in the fermentor tank is inputed to the evaporation alcohol permselective membrane separator by pump, penetrating fluid is collected the concentrated solution that obtains acetone, butanols and ethanol through condenser; Trapped fluid is back to fermentor tank;

(3) with the concentrated solution of the acetone, butanols and the ethanol that obtain in the step (2) by in the pump input extraction tower, concentrated solution is divided into organic phase and water in extraction tower;

(4) water that obtains in the step (3) is drained in the water basin by pump, organic phase directly enters a fourth tower and follow-up rectifying tower group without the wine with dregs tower, and a small amount of water removes acquisition anhydrous propanone, butanols and ethanol in the realization organic phase; Water in the water basin is concentrated through infiltration evaporation alcohol permselective membrane assembly, and concentrated solution enters extraction tower and re-starts and be separated so circulation.

2. technique according to claim 1 is characterized in that, in the fermented liquid of extracting out in the fermentor tank described in the step (2), the concentration of acetone, butanols and total ethanol solvent reaches 18-20g/L.

3. technique according to claim 1 is characterized in that, the total solvent mass concentration of acetone, butanols and the ethanol concentrated solution that obtains through the condenser collection described in the step (2) reaches 100-400g/L.

4. technique according to claim 1 is characterized in that, the total solvent mass concentration reaches 500-700g/L in the organic phase that extraction tower obtains described in the step (3), and aqueous phase total solvent mass concentration reaches 80-280g/L.

5. technique according to claim 1, it is characterized in that, evaporation alcohol permselective membrane separator described in the step (2) is comprised of one or more evaporation alcohol permselective membrane separator, and the per-meate side of each unit evaporation alcohol permselective membrane separator is passed through the pipeline serial or parallel connection in the vacuum pump main pipe rail.

6. the technique described in according to claim 1 is characterized in that, evaporation alcohol permselective membrane is organic membrane, mineral membrane or hybrid organic-inorganic film described in the step (2); Its membrane module form is rolling, tubular type, plate and frame or tubular fibre formula.

7. the technique described in according to claim 6 is characterized in that, the material of hybrid organic-inorganic film is a kind of among PDMS-Silicalite-1, PDMS-ZSM-5 and the PTMSP-Silicalite-1; The material of organic membrane is silicon rubber, poly-trimethyl silicane propine, polypropylene, polyvinylidene difluoride (PVDF) or tetrafluoroethylene; The material of mineral membrane is Silicalite-1 or ZSM-5.

8. the technique described in according to claim 1 is characterized in that, extraction tower described in the step (3) is a kind of in extraction spray column, sieve-tray tower, rotating disc contactor and the pulse-column.

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