KR101929631B1 - Method for manufacturing 1,3-butadien using microbial fermentation - Google Patents

Abstract

The present invention relates to a method for producing 1,3-butadiene by microbial fermentation, which comprises isolating a strain from a fermentation stock solution, separating ethanol from the recycled fermentation stock solution, recovering acetic acid recovered from the residual fermentation stock solution economically by acetaldehyde Followed by condensation reaction of the ethanol and acetaldehyde to prepare 1,3-butadiene.
According to the present invention, acetic acid, which is a by-product of fermentation, is separated and converted into acetaldehyde, which is a reaction intermediate, and then introduced into a condensation reactor for production of 1,3-butadiene with ethanol, There is an effect that the yield of butadiene can be dramatically improved.
According to the present invention, it is possible to reduce the content of organic matter in the fermentation wastewater, or to simplify the processes required for the treatment of the organic matter contained in the fermentation waste liquid, thereby achieving an eco-friendly production process.

Description

[0001] The present invention relates to a method for producing 1,3-butadiene using microbial fermentation,

The present invention relates to a process for producing 1,3-butadiene by microbial fermentation, and more particularly, to a process for producing 1,3-butadiene by fermenting microbial fermentation, -Butadiene can be increased.

When the saccharide obtained after the saccharification process of saccharides or whole, woody, marine microorganisms is fermented into yeast or bacteria, ethanol can be produced according to the following reaction formula (1). Fermentation proceeds under anaerobic conditions and can be converted to acetic acid under exhalation conditions.

Reaction 1: C ₆ H ₁₂ O ₆ → 2 C ₂ H ₅ OH + 2 CO ₂

Alternatively, ethanol is prepared by fermenting a mixed gas containing carbon monoxide (CO) or carbon monoxide into an anaerobic microorganism belonging to the genus Clostridium. For example, U.S. Patent No. 5,173,429 discloses Clostridium difficile ATCC No. 49587 for fermenting a gas mixture containing carbon monoxide to produce ethanol.

In another example, U.S. Pat. No. 5,807,722 describes a method for converting waste gas containing carbon monoxide to organic acids and alcohols using Clostridium jali variant ATCC No. 55380.

Ethanol is produced from carbon monoxide according to the formula below.

Reaction Scheme 2: 6CO + 3H ₂ O? C ₂ H ₅ OH + 4CO ₂

Scheme _{3: 12H 2 + 4CO 2 →} 2C 2 H 5 OH + 6H 2 O

US Pat. No. 8,143,037 discloses a concentration of ethanol in the stock solution of fermentation broth of about 20 g / L after about 1000 hours from the start of fermentation, and the fermentation broth contains a very low concentration of ethanol. A high concentration of ethanol from the fermentation stock solution is recovered through a vacuum stripping process and is further concentrated to 95% to 98% purity by distillation or by selective removal of water after distillation.

A method for chemically converting ethanol to 95% or more to produce 1,3-butadiene is well known. For example, the Lebedev process has been known since the 1930s as a first-stage chemical conversion of ethanol to produce 1,3-butadiene, a raw material for synthetic rubber. Two molecules of ethanol have been converted to form 1,3-butadiene Water and hydrogen.

Scheme 4: 2CH ₃ CH ₂ OH -> C ₄ H ₆ + 2H ₂ O + H ₂

Scheme 4 above is performed using a metal oxide catalyst at 400 < 0 > C to 500 < 0 > C.

In another example, the Ostromislensky process is a two-step reaction in which an aldehyde obtained through a one-stage chemical conversion to obtain acetaldehyde by a dehydrogenation reaction of ethanol and an aldol condensation reaction with acetaldehyde obtained through a one- .

Scheme 5: CH ₃ CH ₂ OH -> CH ₃ CHO + H ₂

Scheme 6: CH ₃ CH ₂ OH + CH ₃ CHO -> C ₄ H ₆ + 2H ₂ O

Reaction Scheme 5 is performed using a catalyst selected from metal oxides, metal salts and metal complexes from copper or copper at a temperature of about 300 ° C., and Scheme 6 shows a reaction between metal oxides, metal salts and metal complexes from tantalum or tantalium It is known to be carried out using selected catalysts.

According to a study by the Pennsylvania State University, the production of 1,3-butadiene per year by using 95% ethanol obtained from fermentation and purification processes from saccharides as raw materials, It is known that about 554,000 tons of 95% pure ethanol is needed (Senior Design Report CBE 459, 2012).

The fermentation stock solution of the mixed gas containing carbon monoxide or carbon monoxide is produced as a by-product from 0.1 to 1 weight of acetic acid per 1 weight of ethanol. The weight ratio of ethanol and acetic acid contained in the final fermentation stock solution varies depending on the fermentation time.

U.S. Patent No. 8,143,037 discloses about 16 g / L of acetic acid tite for 20 g / L of ethanolite after about 1000 hours of fermentation. Acetic acid is produced by the following equation.

Scheme 7: 4CO + 2H ₂ O -> CH ₃ COOH + 2CO ₂

According to Reaction Schemes 2 and 7, a total of 10 moles of carbon monoxide is required to obtain 1 mole of ethanol and 1 mole of acetic acid, and 6 moles of carbon dioxide is generated. If a total of 10 moles of carbon monoxide is fermented to produce 1 mole of ethanol and acetic acid, the theoretical carbon efficiency is 40% by the equation below.

Theoretical carbon efficiency (%) = (number of moles of ethanol produced X 2 + number of moles of produced acetic acid X 2) X 100 (%) / (number of moles of carbon monoxide consumed)

The boiling point of ethanol is about 78.3 ° C, which is lower than that of water. It is easy to purify and concentrate through stripping and further distillation process under vacuum condition. However, to separate acetic acid from the remaining fermentation solution after separating ethanol with boiling point of 117.8 ° C, Cost is required, and when acetic acid is recovered, the economical efficiency of the whole process may be lowered. If the acetic acid is not recovered in terms of process economy, the theoretical carbon efficiency is reduced to 20%.

Therefore, when 95% ethanol is separated and concentrated from the fermentation liquid of a mixed gas containing carbon monoxide or carbon monoxide, and the process of producing 1,3-butadiene through the Rebeved process or the Aostromes lansky process is constituted, And in addition, the process economy can be seriously undermined.

Korean Patent Publication No. 10-2015-0068925 (June 22, 2015) Korean Patent Publication No. 10-2014-0145935 (December 24, 2014) Korean Patent No. 10-1681159 (2016.11.24) Korean Patent No. 10-1317447 (Apr. 20, 2013) U. S. Patent No. 5,173, 429 (Dec. 22, 1992) U. S. Patent No. 5,807, 722 (September 15, 1998) United States Patent No. 8,143,037 (Mar. 27, 2012)

Chae Ho Jung, NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 32, No. 4, 2014, pp. 506-513

The present inventors have made extensive efforts to develop a method for economically producing high purity 1,3-butadiene. As a result, the strain is separated from the fermentation stock solution, the ethanol is separated from the recycled fermentation stock solution, the acetic acid recovered from the residual fermentation stock solution is economically recovered, and the resulting acetaldehyde is converted into acetaldehyde, The inventors of the present invention have found that the process efficiency can be increased by injecting them into the Misrensche process, thereby completing the present invention.

Accordingly, an object of the present invention is to provide a method for economically producing high-purity 1,3-butadiene from a fermentation stock solution obtained by fermenting a mixed gas containing carbon monoxide or carbon monoxide.

According to one aspect of the present invention, the present invention provides a process for preparing 1,3-butadiene comprising the steps of: (a) removing from a fermentation stock solution obtained by fermenting a gas containing CO a first liquid phase stream comprising ethanol ; (b) transferring the residual fermentation stock solution containing acetic acid separated from the first liquid phase flow from the fermentation stock solution of step (a) to the adsorption tower to adsorb acetic acid; (c) introducing hydrogen into the adsorption tower of step (b) to desorb acetic acid and providing a second liquid stream comprising acetaldehyde obtained through the acetic acid conversion reaction; And (d) condensing the first liquid stream of step (a) and the second liquid stream of step (c) to recover 1,3-butadiene.

In one embodiment of the present invention, the first liquid stream and the second liquid stream are continuous streams.

&Quot; Continuous flow ", which describes the liquid and vapor phase flows of the present invention, is not a flow that is broken off at the end of each step, but rather a flow is continuously created while all steps included in the present invention are performed .

The present inventors have made extensive efforts to develop a method for economically producing high purity 1,3-butadiene. As a result, it has been found that ethanol can be separated from the fermentation stock solution, the acetic acid recovered from the residual fermentation stock solution can be economically recycled to acetaldehyde, and then recycled to the process to increase the process efficiency.

The method of the present invention is described step by step as follows:

(A) separating a first liquid stream comprising ethanol from a fermentation stock solution obtained by fermenting a gas containing CO

The step (a) of the present invention is a step of fermenting a gas containing CO or CO to produce ethanol and separating ethanol therefrom for the production of the fermentation stock solution.

According to the introduction method of the raw material gas containing carbon monoxide or carbon monoxide, the fermentation tank may be a Fed Batch type fermentation tank or alternatively may be a recycling fermentation tank including recycling of unreacted gas. In the present invention, The form of the fermenter and the accessories can be freely configured according to the convenience of the process composition if the fermentation effluent can be discharged continuously without any restriction of the form of the fermentation tank and the continuous supply of the mixed gas including carbon monoxide and carbon monoxide can do.

In one embodiment of the invention, the fermentation of step (a) is carried out in the presence of Clostridium, Moorella, Oxobacter, Peptostreptococcus, Acetobacterium, Eubacterium or Butyribacterium strains of the genus Escherichia. Conventional methods known in the related art can be used for the fermentation method of the mixed gas.

The strain isolated from the fermentation broth fermenting the mixed gas containing carbon monoxide or carbon monoxide is recycled to the fermenter. The strain used for fermentation is a strain capable of producing ethanol through fermentation of carbon monoxide, and may be of wild type or genetically engineered type.

When a mixture of ethanol and water is separated from the fermentation broth in which the strain has been isolated from the fermentation broth through the ethanol stripping process, the remaining fermentation broth contains acetic acid, medium components, and fermented solid.

A mixture of ethanol and water is introduced into the distillation column to obtain 95% of ethanol at the top and water containing a small amount of ethanol at the bottom. The water obtained from the bottom of the distillation column can be cooled or circulated to the fermenter after the heat is recovered or discarded into the waste water. 95% of the ethanol is fed to a chemical conversion reactor comprising the Lebedev process or the Ostromislensky process.

Step (b): a step of transferring the residual fermentation stock solution containing acetic acid separated from the first liquid phase flow from the fermentation stock solution of step (a) to the adsorption tower to adsorb acetic acid

Step (b) of the present invention is a step of separating ethanol by ethanol stripping and then removing the residual fermentation stock solution after sedimentation or filtration to remove the solid component, and then introducing it into the acetic acid adsorption tower. If necessary, a specific ingredient constituting the medium may be precipitated by an acid-base neutralization reaction or a chemical reaction and removed together with the solid matter.

In one embodiment of the present invention, the adsorption tower of step (b) comprises at least one selected from activated carbon, carbon nanotube, and activated carbon fiber as an adsorbent. The adsorbent may be impregnated with an acid, metal or metal salt on the surface or inside thereof.

Acetic acid is separated from water and adsorbed on the adsorbent while passing through the packed bed composed of the adsorbent inside the adsorption tower, and the crude solution containing the small amount of acetic acid is discharged to the outlet of the adsorption column. The adsorbent may be an activated carbon, a carbon nanotube, an activated carbon fiber and a substance in which an acid, a metal salt, a metal, or an organic matter is impregnated on the surface.

Step (c): introducing hydrogen into the adsorption column of step (b) to desorb acetic acid, and then providing a second liquid stream comprising acetaldehyde obtained through the acetic acid conversion reaction

In the step (c) of the present invention, hydrogen is injected into the adsorption column to selectively desorb the acetic acid adsorbed in step (b) and convert it to acetaldehyde. The gas injected for the desorption of acetic acid may be nitrogen, carbon dioxide, argon, helium, or a combination thereof. However, it is preferable from the viewpoint of efficiency to use hydrogen because of the characteristics of the continuous flow process of the present invention.

The adsorption tower is composed of two or more so that the switching operation can be performed to constitute a continuous flow process.

For example, when the adsorption is completed in the first adsorption tower, the flow of the fermentation stock solution introduced into the adsorption tower inlet is blocked and high temperature hydrogen gas is blown into the adsorption tower. Acetic acid is desorbed from the adsorbent and introduced into the acetic acid conversion reactor together with the hydrogen gas. The apparatus may be constituted by an apparatus for adjusting the pressure, adjusting the temperature, and transferring the fluid between the outlet of the adsorption tower and the inlet of the acetic acid conversion reactor. In the present invention, a series of processes constituted by these apparatuses and apparatuses are not particularly limited.

The gaseous stream containing acetic acid is introduced into the acetic acid conversion reactor and passed through a catalyst bed comprising 20 wt% palladium on 80 wt% iron oxide. At this time, the acetic acid conversion reactor was maintained at 300 캜 and 18 atm. In the acetic acid conversion reactor, about 30 to 50% of acetic acid is converted to acetaldehyde, and the resulting acetaldehyde and hydrogen are introduced into a chemical conversion reactor constituting the Levedev process or the Aostromisenski process, and the unconverted acetic acid is recycled do.

In the acetic acid conversion reactor, the reaction of Scheme 8 proceeds.

Scheme 8: CH ₃ COOH + H ₂ → CH ₃ CHO + H ₂ O

Ethanol or ethyl acetic acid may be partially produced as a by-product, but the effect on 1,3-butadiene formation is not significant.

The production of 1,3-butadiene from ethanol does not cause the generation of carbon dioxide, so the theoretical carbon efficiency can be regarded as 100%. Therefore, the theoretical carbon efficiency of 1,3-butadiene from carbon monoxide as the fermentation raw material is the same as that of formula 1, and it can not exceed 20% when acetic acid is not recovered.

In one embodiment of the present invention, the acetic acid conversion reaction of step (c) is performed in the presence of at least one selected from the group consisting of Fe, Ti, Mg, Si, Cr, Al, Zn, Mn, Ni, K, Na, Zr, Pt, Pd, Ru, Ir, Co, and metal oxides, metal salts and metal complexes therefrom.

(D) recovering 1,3-butadiene by condensation reaction of the first liquid phase stream of step (a) and the second liquid phase stream of step (c)

Step (d) of the present invention is a step of condensing a first liquid phase stream containing ethanol and a second liquid phase stream containing acetaldehyde to prepare 1,3-butadiene therefrom.

In one embodiment of the invention, the first liquid stream of step (d) is part of the ethanol content converted to acetaldehyde by the dehydrogenation reaction.

In one embodiment of the present invention, the dehydrogenation reaction is performed at 100 ° C to 500 ° C. In another embodiment of the present invention, the dehydrogenation reaction is performed at 200 ° C to 400 ° C. In certain embodiments of the present invention, the dehydrogenation reaction is carried out at 300 ° C to 350 ° C.

In one embodiment of the present invention, the dehydrogenation reaction is carried out at 1 to 50 atm. In another embodiment of the present invention, the dehydrogenation reaction is carried out at a pressure of 1 to 20 atm. In certain embodiments of the present invention, the dehydrogenation reaction is conducted at 1 to 5 atm.

In one embodiment of the present invention, the dehydrogenation reaction is carried out in the presence of Fe, Ti, Mg, Si, Cr, Al, Zn, Mn, Ni, K, Na, Zr, Zn, Cu, Ag, Ta, Pt, , Ir, Co, and metal oxides, metal salts and metal complexes therefrom. In another embodiment of the present invention, the dehydrogenation reaction uses at least one selected from metal oxides, metal salts and metal complexes from copper and copper as a catalyst.

In one embodiment of the present invention, the condensation reaction of step (d) is carried out at 100 ° C to 600 ° C. In another embodiment of the present invention, the condensation reaction of step (d) is carried out at 200 ° C to 500 ° C. In certain embodiments of the present invention, the condensation reaction of step (d) is carried out at 300 ° C to 400 ° C.

In one embodiment of the present invention, the condensation reaction of step (d) is carried out at 1 to 100 atm. In another embodiment of the present invention, the condensation reaction of step (d) is carried out at 1 to 20 atm. In certain embodiments of the present invention, the condensation reaction of step (d) is carried out at 2 to 10 atm.

In one embodiment of the present invention, the condensation reaction of step (d) is carried out in the presence of at least one of Fe, Ti, Mg, Si, Cr, Al, Zn, Mn, Ni, K, Na, Zr, Zn, Pt, Pd, Ru, Ir, Co, and metal oxides, metal salts and metal complexes therefrom. In another embodiment of the present invention, the condensation reaction uses at least one selected from metal oxides, metal salts and metal complexes from tantalum and tantalum as catalysts.

The effects of the present invention can be further specified by the following Comparative Examples and Examples. The carbon efficiencies given in the comparative examples and the examples are calculated by taking into account only the carbon monoxide in the process and the flow of the carbon-containing compound converted therefrom, except for the thermal energy and the electric energy necessary for the constitution of the process.

The principle of the present invention and the technology to be implemented by the present invention can be applied to the construction of a fusion process in which a fermentation process or a fermentation process and a chemical conversion process are combined through minor modifications well known to those skilled in the art But are not limited to the embodiments of the invention.

The features and advantages of the present invention are summarized as follows:

The present invention provides a method for economically producing high-purity 1,3-butadiene from a fermentation stock solution obtained by fermenting a mixed gas containing carbon monoxide or carbon monoxide.

By using the production method of the present invention, the carbon efficiency can be increased and the yield of 1,3-butadiene can be improved, so that the 1,3-butadiene can be effectively used for the economical production of 1,3-butadiene.

In addition, there is an advantage that it is possible to reduce the content of organic matter in the fermentation wastewater generated in the process, simplify the treatment of the organic matter contained in the fermentation waste liquid, and thus produce eco-friendly products.

1 shows a process for producing 1,3-butadiene from a mixed gas containing carbon monoxide or carbon monoxide according to the present invention.
FIG. 2 is a schematic diagram illustrating the construction of an adsorption column designed to separate acetic acid from the remaining fermentation broth after stripping ethanol, and the concept of switching operation designed for continuous operation.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Comparative Example 1: Production of 1,3-butadiene by the Levette process

Carbon monoxide was introduced into the fermenter at a rate of 10 kg / hr. Some of the introduced carbon monoxide was fermented and converted into ethanol, acetic acid, and trace alcohols and organic acids. The remainder was discharged from the fermenter and then combined with the additional carbon monoxide and recycled to the fermenter. After 100 hours of fermentation, the titers of ethanol and acetic acid reached 20 g / L and 15 g / L, respectively. The production rates of ethanol and acetic acid were 1 kg / hour and 0.75 Kg / hour, respectively.

The carbon efficiency of the fermentation process is about 19% when the trace amounts of alcohols and organic acids produced in the fermentation process are negligible. Table 1 below shows the carbon efficiency of the fermentation process when 1 kg of ethanol is obtained per hour.

Reactant Consumption (kg / hr) Product yield (kg / hour) carbon monoxide water ethanol Acetic acid carbon dioxide 5.05 1.62 1.00 0.75 4.93

The efficiency of fermentation was determined by stripping ethanol from a certain amount of the fermentation broth to make an ethanol-rich stream, which was further distilled to obtain 95% ethanol at a production rate of 1.04 kg / hr per hour. The yield of ethanol after stripping and distillation was 99%.

95% ethanol was introduced at the inlet of the Reveved conversion reactor at a flow rate of 1.042 kg per hour. The temperature of the reactor was 425 DEG C and the pressure was 5 atm. Ethanol introduced into the reactor was converted to a mixed gas of 1,3 butadiene, ethylene, acetaldehyde, diethyl ether, and the like in the presence of Cu (1 wt%) / SiO ₂ -MgO catalyst.

The conversion and selectivity of ethanol were 70% and 48%, respectively, and the yield of ethanol was 33.6%. The product gas mixture discharged from the reactor outlet was introduced into the separation and purification process for the recovery of 1,3-butadiene, wherein the separated ethanol was recycled and bound to the 95% ethanol stream and then introduced to the inlet of the Rebeved conversion reactor .

When the unreacted ethanol is recycled, the net flow rate of ethanol introduced into the inlet of the reactor during steady state operation is 1.58 kg per hour, and the yield per hour of 1,3-butadiene in the mixed gas discharged to the reactor outlet is 0.31 kg .

Comprehensively summarizing the above process, 5.05 kg per hour of carbon monoxide was fermented to obtain 0.31 kg of 1,3-butadiene per hour, and the theoretical carbon efficiency was 12.8% when 1,3-butadiene was produced from carbon monoxide .

Comparative Example 2: Production method of 1,3-butadiene by the osmolysis process

The method of obtaining 95% ethanol from carbon monoxide is the same as that of Comparative Example 1.

95% of ethanol was introduced into the dehydrogenation reactor, the first of the two successive reactors constituting the Ostromislenkie process, at a flow rate of 1.042 kg per hour, and a portion of the ethanol was converted to acetaldehyde and hydrogen by Scheme 5 . The operating temperature of the dehydrogenation reactor was 325 ° C, the operating pressure was 2.5 atm, and a copper-chromium oxide catalyst was used. At this time, the ethanol conversion was 50% and the selectivity of acetaldehyde was 92%.

The mixed gas containing 0.495 kg of ethanol and 0.436 kg of acetaldehyde per hour discharged through the outlet of the reactor was introduced into the condensation reactor which is the second reactor and converted to 1,3-butadiene by the reaction scheme 6. The operating temperature was maintained at 390 ° C and the operating pressure was maintained at 6.5 atmospheres. Using tantalum oxide-silica catalyst, conversion of 44.5% and selectivity of 1,3-butadiene of 55% were obtained, and diethyl ether, acetic acid, ethyl Acetate, n-butanol, 1-butene ethylene, and hexadiene.

From the second reactor outlet stream, 1,3-butadiene was separated and purified to give the product, unreacted ethanol and acetaldehyde were recycled to the inlet of the second reactor and merged with the outlet stream of the first reactor and introduced into the second reactor. During steady-state operation, including recycle flow, the yield of 1,3-butadiene in the reactor outlet stream was 0.369 kg per hour.

Comprehensively summarizing the above process, 5.05 kg per hour of carbon monoxide was fermented to obtain 0.36 kg of 1,3-butadiene per hour, and the theoretical carbon efficiency was 15.1% when 1,3-butadiene was produced from carbon monoxide .

Example 1: Production of 1,3-butadiene by acetic acid conversion reaction

The method of obtaining 95% ethanol from carbon monoxide is the same as that of Comparative Example 1.

In the 95% pure ethanol obtained at a flow rate of 1.042 kg per hour through the fermentation process and separation and purification process, 0.476 kg of ethanol per hour was introduced into the dehydrogenation reactor in the same manner as in Comparative Example 2 to be converted into acetaldehyde. The operating temperature, the operating pressure, and the catalyst of the dehydrogenation reactor were the same as those of Comparative Example 2, and the conversion of ethanol was 50% and the selectivity of acetaldehyde was 92%.

The flow rate of ethanol in the dehydrogenation reactor outlet flow was 0.226 kg per hour and the flow rate of acetaldehyde was 0.199 kg per hour. The outlet stream was combined with a flow of 0.566 kg of 95% pure ethanol per hour which was not introduced into the dehydrogenation reactor during the total flow rate of ethanol. Then combined with a flow of 0.473 kg of acetaldehyde per hour produced in the acetic acid conversion reactor described below and introduced into the condensation reactor which is the second reactor.

The introduction stream of the condensation reactor with the three streams combined contains 0.764 kg of ethanol per hour and 0.672 kg of acetaldehyde per hour. 9.84 g of hydrogen per hour discharged from the dehydrogenation reactor was combined with an additional 15.16 g of hydrogen flow per hour supplied to the adsorption tower inlet described below to promote desorption of acetaldehyde.

On the other hand, the ethanol was separated and the remaining fermentation liquid was passed through the solids removal device shown in FIG. 1 and the solid component was removed, and then introduced into the inlet of the adsorption tower filled with activated carbon adsorbent. Acetic acid in the stock solution of fermentation introduced into the inlet of the adsorption tower corresponds to 0.75 kg per hour. After the adsorption of acetic acid was completed, the flow of the fermentation stock solution introduced into the adsorption tower was switched to the second adsorption tower and desorbed at the temperature of 250 ° C. to the inlet of the adsorption tower.

At this time, hydrogen gas was blown at a flow rate of 25 g per hour to promote desorption of acetic acid. The mixed gas of desorbed acetic acid and hydrogen was introduced into the acetic acid conversion reactor through a storage tank serving as a separate buffer. The flow rate of acetic acid introduced into the acetic acid conversion reactor is 0.75 kg per hour and the flow rate of hydrogen is 25 g per hour.

The acetic acid conversion reactor obtained a conversion of 47% and an acetaldehyde selectivity of 86% using an iron oxide catalyst containing 20 weight percent palladium at a temperature of 300 < 0 > C and a pressure of 18 atm. Unreacted acetic acid and hydrogen were recycled and combined with a mixed stream of acetic acid and hydrogen fed to the feedstock and introduced into the reactor inlet. The total flow rate of acetic acid introduced into the reactor inlet during steady state operation, including the recycle flow, was 1.25 kg per hour, the total flow rate of hydrogen was 54.3 g per hour, and the amount of acetaldehyde produced was 0.473 kg per hour.

Acetaldehyde produced in the acetic acid conversion reactor and separated and purified was introduced into the condensation reactor, which is the second reactor, in combination with the other two streams as described above, at a flow rate of 0.453 kg per hour.

0.764 kg of ethanol per hour and 0.672 kg of acetaldehyde per hour contained in the condensation reactor inlet introduction stream were converted to 44.5% conversion using the same catalyst at the same reaction temperature and reaction pressure as in Comparative Example 2, , And 3-butadiene selectivity was 50%.

During steady-state operation, including recycle flow, the yield of 1,3-butadiene in the reactor outlet flow was 0.535 kg per hour.

Comprehensively summarizing the above process, 5.05 kg per hour of carbon monoxide was fermented and 0.31 kg of 1,3-butadiene was obtained per hour. When 1,3-butadiene was produced from carbon monoxide, the theoretical carbon efficiency was 22.0% .

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (12)

A process for preparing 1,3-butadiene comprising the steps of:
(a) separating a first liquid stream comprising ethanol from a fermentation stock solution obtained by fermenting a gas containing CO;
(b) transferring the residual fermentation stock solution containing acetic acid separated from the first liquid phase flow from the fermentation stock solution of step (a) to the adsorption tower to adsorb acetic acid;
(c) introducing hydrogen into the adsorption column of step (b), desorbing acetic acid using a catalyst comprising 80% by weight of iron oxide and 20% by weight of palladium and then separating acetic acid from the second Providing a liquid stream; And
(d) using the at least one catalyst selected from metal oxides, metal salts and metal complexes from tantalum and tantalum as a catalyst to convert the first liquid phase stream of step (a) and the second liquid phase stream of step (c) And recovering 1,3-butadiene, wherein the first liquid phase stream comprises at least one selected from the group consisting of metal oxides, metal salts and metal complexes from copper and copper at 300 ° C to 350 ° C, 1 to 5 atmospheres Recovering 1,3-butadiene, wherein a portion of the ethanol content is converted to acetaldehyde by the dehydrogenation reaction employed.
The method according to claim 1, wherein the fermentation in step (a) is carried out in the presence of at least one selected from the group consisting of Clostridium, Moorella, Oxobacter, Peptostreptococcus, Acetobacterium, Characterized in that the strain is caused by a strain belonging to the genus Eubacterium or Butyribacterium.
The method according to claim 1, wherein the adsorption tower of step (b) comprises at least one selected from the group consisting of activated carbon, carbon nanotube, and activated carbon fiber as an adsorbent.
The method according to claim 3, wherein the adsorbent is an acid, metal or metal salt impregnated on the surface or inside thereof.
delete delete delete delete delete The process according to claim 1, wherein the condensation reaction of step (d) is carried out at 100 ° C to 600 ° C.
The process according to claim 1, wherein the condensation reaction of step (d) is carried out at a pressure of 1 to 100 atm.
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