JPS59216591A - Production of butanol - Google Patents

Abstract

PURPOSE:To recover efficiently and easily butanol, by extracting the butanol from a fermentation liquor with a higher alcohol based extracting agent in producing the butanol by the fermentation method. CONSTITUTION:Butanol is produced by the fermentation method. In the process, the fermentation is carried out while bringing an extracting agent containing a 10-14C alcohol into contact with a fermentation liquor by introducing the extracting agent from the bottom of a fermenter, and raising the extracting agent in a fermentation liquor, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing furinol, and more particularly to a method for producing butanol that increases the productivity of furinol by fermentation and enables easy recovery. More specifically, the present invention relates to a method for producing butanol in which butanol can be efficiently produced by extracting butanol from a fermentation liquid using a higher alcohol extractant during the production of butanol by fermentation.

Conventionally known as acetone-butanol fermentation, batch fermentation is carried out under anaerobic conditions using carbohydrates or blackstrap molasses as raw materials to produce acetone and butanol.
Furthermore, a small amount of ethanol was recovered. One of the characteristics of this fermentation is that the butanol concentration is 1.5 (W/V
%, fermentation will stop and a culture solution containing a high concentration of butanol cannot be obtained. Another problem with butanol fermentation is that the fermentation rate is slow.

In the production of butanol by fermentation methods, various proposals have been made to eliminate the fermentation inhibition caused by butanol as described above. For example, there is a method of adding castor oil or activated carbon to the fermentation liquid, but these methods pose the following problems when industrialized.

First, when castor oil is added, it forms a strong emulsion with the fermentation liquid, making it difficult to separate and purify.
Moreover, its viscosity is extremely high and it has good heat conductivity.

There is a difference in transportability. On the other hand, when activated carbon is used for adsorption, desorption, regeneration, and purification are required after adsorption, making the operation complicated.

On the other hand, the present applicant proposed so-called extractive fermentation in which an extractant is used in the production of ethanol by a fermentation method (Japanese Patent Publication No. 58-3677).

Therefore, the inventors of the present invention have conducted extensive studies to solve the problems of butanol fermentation, which has many problems as described above, by introducing extractive fermentation technology. However,
As is well known, butanol fermentation differs from ethanol fermentation in that the fermenting bacteria are obligate anaerobic bacteria, that the fermentation products are diverse, including butanol, acetone, ethanol, and hydrogen, and that the main products are Since butanol has differences such as being difficult to dissolve in water, the extraction fermentation conditions for ethanol fermentation cannot be applied as is. Particularly, for extractants, the partition coefficient and oxygen dissolution rate for the main fermentation products.

The material must be selected after careful consideration of its solubility in water, amount of water entrainment, melting point, etc.

In view of the above-mentioned circumstances, the present inventors have repeatedly studied the extraction fermentation conditions, particularly the selection of extractants, when producing butanol by the fermentation method. As a result, they discovered that a specific higher alcohol is suitable as an extraction agent, and based on this knowledge, they completed the present invention.

The present invention provides a method for producing sibutanol by a fermentation method, which is characterized in that fermentation is carried out while bringing an oil containing an alcohol having 10 to 14 carbon atoms into contact with a fermentation liquid. be.

In producing butanol by the fermentation method, any known butanol-producing bacteria can be used.

Microorganisms of the genus Clostridium are well known as butanol-producing bacteria, such as Clostridium spp.
Examples include acetobutylicum. There are no particular limitations on the medium used for fermentation, as long as it allows butanol-producing bacteria to grow and accumulates a sufficient amount of butanol, and any known medium may be used. Further, known conditions such as culture temperature + PH + time may be used, and various fermentation methods such as a continuous method and a two-batch method may be used. Furthermore, it is also possible to perform fermentation using immobilized microbial cells in which butanol-producing microorganisms are immobilized by appropriate means.

Next, in the present invention, butanol fermentation is performed using an extractant containing a higher alcohol having 10 to 14 carbon atoms. The extractant is used to extract the butanol produced by contact with the fermentation liquor. Therefore, the extractant is required to have a high extraction capacity from the fermentation liquor, that is, a high partition coefficient for butanol, the main fermentation product, as well as a slow dissolution rate of oxygen and a high solubility in water. It needs to have properties such as low toxicity, no or low toxicity to butanol-producing bacteria, liquid, and a boiling point higher than that of butanol under normal pressure. As a result of studying extractants that satisfy these conditions, the present inventor found that among various substances, alcohols having 10 to 14 carbon atoms are suitable. Alcohols having 10 to 14 carbon atoms generally have a high partition coefficient of 5 or more with respect to butanol. The distribution coefficient is expressed as the concentration of butanol in the extraction phase/the concentration of butanol in the raffinate phase, and it is usually desirable that the distribution coefficient is 5 or more. When the partition coefficient is 5 or less, the butanol concentration is low when separating butanol from the extractant, so the amount of separation is extremely large and the amount of heat in distillation separation increases, resulting in poor industrial efficiency. Furthermore, when reusing extractants, in order to maintain a constant butanol concentration in the fermentation liquid, the amount of circulation increases and the equipment must be larger, which not only increases the amount of heat required for the separation described above. , further impairing industrial efficiency. In addition, butanol-producing bacteria (Clostridium acetobutylicum IAM-
19013), there is little or no toxicity as shown in Table 1 below. Moreover, this higher alcohol does not dissolve glucose and is easily separated from the fermentation liquid.
It has the property of not forming azeotropes with butanol, acetone, ethanol, etc. Further, the solubility of these alcohols in water is shown in FIG. 2, and the amount of water entrainment is shown in FIG.

Decanol Some undecanol Very little dodecanol No tridecanol No tetradecanol Alcohols with carbon atoms of 9 or less have a solubility in water of approximately 0.05
Since it is high (more than % by weight), extraction agent loss is large, and in addition, those having less than 8 carbon atoms tend to be highly toxic to butanol-producing bacteria. Furthermore, higher alcohols generally tend to solidify at room temperature as the number of carbon atoms increases, but those with 14 or fewer carbon atoms can be used as they are liquid at fermentation temperatures. The higher alcohols used in the present invention include linear alcohols, branched alcohols (1
so-, tert-, etc.) are also included as long as there is no problem with their use.

Among alcohols with 10 to 14 carbon atoms, those with 11 to 1 carbon atoms
No. 3 is preferable, and tridecanol is particularly preferable. In the present invention, alcohols having 10 to 14 carbon atoms may be used alone as extractants, or two or more types may be used in combination.

Furthermore, it can also be used in combination with substances other than alcohol. For example, by using it in combination with an aromatic compound such as benzene or a derivative thereof, separation from water can be easily performed.

In this case, the extractant ratio is usually 50 or more. In addition, the ratio of extractant to fermentation liquid is usually 0.
1-2, preferably 0.25-1.0.

As described above, in the present invention, butanol fermentation is carried out while bringing the extraction agent into contact with the fermentation liquid, but the contact between the two can be carried out in various ways. Contact between the two can be roughly divided into cases where it is carried out within the fermenter and cases where it is carried out outside the fermenter. As a method for bringing the extraction agent and the fermentation liquid into contact within the fermentation tank, there is a method in which, for example, a layer of extraction agent is formed as an upper layer of the fermentation liquid in the upper part of the fermentation tank. According to this method, the fifth
As seen in the figure, the extraction layer provides resistance to oxygen and fermentation liquid. In this case, when replenishing the extractant or reusing the extract that has been separated from the fermentation liquor and collected outside the fermenter, the extractant is introduced from the bottom of the fermenter and allowed to rise in the fermentation liquor. Efficiency can be increased. Alternatively, the extractant in the upper layer may be simply extracted and circulated to the lower part of the fermenter.

Various methods can be considered for bringing the extraction agent into contact with the fermentation liquid outside the fermenter, such as a tank or a tower.

There is a method of bringing the two into contact using an extraction device such as piping. In this case, a circulation system can be formed between the extraction device and the fermentation tank using piping or the like, and part or all of the extraction agent and fermentation liquid can be returned to the fermentation liquid.

When circulating and reusing the extraction agent, by using it as a heating medium, the temperature of the fermentation liquor can be controlled and the butanol fermentation can be made more effective. That is, when the fermentation liquid is directly heated (or cooled), the butanol-producing bacteria may be killed by the heat. On the other hand, when the extraction agent is heated (or cooled) in advance and brought into contact with the fermentation liquid, killing of bacteria can be prevented, and the temperature of the fermentation liquid can also be indirectly controlled using an oil agent. In addition, this indirect temperature control is easier to control, can tolerate some fluctuations, is simpler in terms of equipment, and has great industrial value. Furthermore, when separating the extractant by distillation, the amount of heat during distillation can also be utilized.

Contact between the extraction agent and the fermentation liquid may be carried out continuously from the initial stage of fermentation to the final stage of fermentation, or may be carried out discontinuously, but it is preferable to contact the extracting agent continuously from the early stage of fermentation to maintain a constant level. When the concentration is reached, the supply of the extractant layer to a fermentation product recovery device such as a distillation column is started, and then,
Continuous contact, recovery, and extraction agent circulation. Note that the product recovered by the fermentation product recovery device is usually subjected to distillation or the like to separate and purify the target butanol.

According to the present invention, the fermentation is carried out by bringing a specific extraction agent into contact with the fermentation liquor, and the butanol in the fermentation liquor.

Fermentation products such as acetone are extracted, allowing the concentration of butanol and acetone in the fermentation liquor to be kept low. As a result, the inhibition of fermentation by butanol on bacteria can be weakened and the fermentation rate can be increased.

Therefore, the productivity of fermentation of butanol and the like is significantly improved, and the flow rate of the fermenter can be increased. Furthermore, the extractant used in the present invention has a large boiling point difference with butanol, acetone, etc., and does not form an azeotrope with these, so the two can be separated by flushing or simple distillation. Moreover, since the butanol concentration in the extract is much higher than that in the fermentation liquid, separation and purification can be carried out extremely economically.

Furthermore, when the extraction agent is used in circulation, by cooling it to an appropriate temperature and using it, the temperature of the fermentation liquid can be controlled and used as a heating medium, thereby improving fermentation efficiency. In addition, the bacterial cells accompanying the extract from the fermenter are separated by means such as filtration or sedimentation before being separated from the extract.
It can be returned to the fermenter, but if return is not required, it may be separated from the extract by means such as passing through or sedimentation.

As described above, the present invention has many advantages and can efficiently produce butanol by fermentation. Note that when acetone and ethanol are produced together with butanol, these can also be separated and purified according to the present invention.

Next, the present invention will be explained in detail using examples.

Example 1 150'? After adjusting the medium to pH 6.5 to which 1 t/l of glucose was added,
2 was put into a fermenter and sterilized.

After cooling, spread the inoculum at 25m/! I put it in. In addition, as an inoculum, Clostridium acetobutylicum IAM was prepared in advance in a medium containing 50 f//l of glucose and having the composition shown in Table 2.
-19013 was cultured at 37°C for 24 hours and then subplanted.

After adding the starter, purge the fermenter with nitrogen for 30 minutes.
Next, 500 all of extractant 1-1) decanol was added. Thereafter, anaerobic fermentation was performed at 378C for 66 hours while stirring at 1100 rpm.

From 15 hours after the start of fermentation, the extract layer at the top of the fermenter is
It was circulated to the bottom of the fermenter at a rate of 0 me/hr to help absorb norbento, a fermentation product, in the fermentation liquid. After the completion of fermentation, 11 degrees of turben in the fermentation liquor and oil phase was added to the third
The table shows the vapor composition of the oil phase flashed at 120°C.
Shown in the table.

KH2PO40,8 to 2HPO40,8 gSO42 MnS() + HzOO,01 FeSO4・7H200,0! NaC21.0 Cysteine 0.5 Asparagine 2 Yeast Extract
5Table 3 (Unit: g/l) Acetone 8.0 5.3 Butanol 5.6 41.6 Ethanol
3.1 1.3 Acetone
8 Butanol 66 Ethanol 2 Water 24 Example 2 Continuous fermentation of acetone-butanol was carried out using Clostridium acetobutylicum JAM-19013 using the apparatus and flow sheet shown in FIG. 30 f
After adjusting the pH of the medium shown in Table 2 containing /l of glucose to 5.5, the medium was poured into a 2L fermenter C from the medium storage tank A, sterilized by a conventional method, and cooled. 25 all of the same inoculum were injected.

After the inoculum was added, the fermenter was purged with nitrogen for 30 minutes, and then pre-sterilized tridecanol was added from the 500 ml extract storage tank B. After adding the extractant, batch fermentation was carried out at 37℃ for 30 hours while stirring at 1100 rpm, and then 90
A medium having the composition shown in Table 2 containing f/l glucose was continuously supplied from medium storage tank A to fermenter C at a flow rate of 20 me/hr.

On the other hand, 1 liter of sterilized extractant tridecanol was added from extractant storage tank B.
It was continuously fed into the lower part of fermenter C at a flow rate of 0 me/hr. The pH of the fermentation liquid was still maintained at 6.0 with 20% NaOH in the alkaline storage tank and 0.1 MHIJ in the acid storage tank E, and the operation was continued for 9 days.

During the fermentation period, an extractant layer was formed in the upper part of the fermentation liquid in fermenter C to prevent trace amounts of oxygen in the gas phase from dissolving into the fermentation liquid. The two phases of fermentation liquor and extractant leaving fermenter C are sent to fermentation liquor receiving tank F and extracting agent receiving tank G [7]. The oil phase was flashed at 120°C to recover the fermentation product.

Table 5 shows the degree of norbento in the fermentation liquor and oil phase, and Table 6 shows the vapor composition of the product recovered by flashing.

Acetone 53 Butanol 3 23 Ethanol 1.7 0.8 Solvent
Steam composition book) Acetone 7 Butanol 56 Ethanol 2 Water 35 Example 3 Continuous fermentation of acetone and butanol was carried out using Clostridium acetobutylicum IAM-19013 using the apparatus and flow sheet shown in FIG. A medium having the composition shown in Table 2 containing 30 g/l of glucose was saturated with the extractant tridecanonyl, and 500 m/l of the extract was saturated. Fermenter C
After sterilization, batch fermentation was carried out at 37°C for 30 hours. Next, a medium having the composition shown in Table 2 containing 45 fl/l of glucose and saturated with extractant tridecanol was continuously supplied from medium storage tank A to fermenter C at a flow rate of 10 ml/hr.

Fermentation was carried out in fermenter C for 9 days at 37°C and pH 6.0. PH adjustment is done with NaO 20 in alkaline storage tank G.
H and O of the acid storage tank H, ], M HIJ was used.

The fermented liquid from fermentation tank C is sent to an extraction tower with a diameter of 7crIL filled with a 60cm high gold-copper packing, and the pre-sterilized oil tridecanol 20ae sent from extractant storage tank B is sent to
/f1r. The fermentation liquor from which the solvent, which is a fermentation product, was extracted was sent to fermentation liquor storage tank E. In addition, the oil phase from which the fermentation products have been extracted is sent to the extract liquid storage tank F, and then 12
The fermentation product was collected by flashing at 0°C. Table 7 shows the solvent concentrations in the fermentation broth and oil phase, and the solvent concentrations recovered by flashing Table 7 (Unit: f/l) Acetone 2.4 1.8 Butanol 0.1 40 Ethanol
0.1 0.06 acetone
3.1 Furinol 70.4 Ethanol 0.1 Water 26.4 Example 4 Anaerobic treatment was carried out in the same manner as in Example 1 using the medium shown in Table 2 to which 150 i/l glucose was added and using dodecanol as the extractant. Batch fermentation was carried out for 68 hours under these conditions. Table 9 shows the M1 degrees in the fermentation liquor and oil phase after the completion of fermentation, and the vapor composition of the product recovered by flashing is shown in Table 1.
Shown in Table 0.

Table 9 (Unit: r/l) Acetone 0.89 0.7 Butanol 6.0 53 Ethanol 0.34 0.2 Acetone
8 Butanol 65 Ethanol 2 Water 25

[Brief explanation of the drawing]

Figure 1 is a graph showing the solubility of higher alcohols in water.
FIG. 2 is a graph showing the amount of water entrained in higher alcohols. FIGS. 3 and 4 show the apparatus and flow sheet used in the embodiment of the present invention. FIG. 5 is a graph showing the dissolved oxygen concentration in the fermentation liquor with and without an extraction layer when air is blown into the gas phase of the fermenter. Figure 1 @, @”yl ref - 1 Shino Po 11 Ya Gap 2nd Figure Currency 9 Ryocho 1 Shitsu - 2 Shino Thorn Si 4

Claims (1)

[Scope of Claims] 1) A method for producing butanol by a two-fermentation method, which comprises carrying out fermentation while bringing an extractant containing an alcohol having 10 to 14 carbon atoms into contact with a fermentation liquid. 2) The production method according to claim 1, wherein the contact between the extraction agent and the fermentation liquid is carried out in a fermenter. 3) The production method according to claim 1 or 2, wherein the extraction agent and the fermentation liquid are brought into contact by forming a layer of extraction agent in the upper part of the fermenter. 4) The production method according to any one of claims 1 to 3, wherein the contact between the oil agent and the fermentation liquid is carried out by introducing the extraction agent from the lower part of the fermentation tank and raising it in the fermentation liquid. 5) The production method according to claim 4, wherein the extractant introduced from the lower part of the fermenter is one extracted from the extractant layer, from which -1 or butanol has been separated. 6) The production method according to claim 1, wherein the extraction agent and the fermentation liquid are brought into contact with each other in an extraction device outside the fermenter. 7) The production method according to claim 6, wherein the extracting agent and the fermentation liquid are brought into contact with each other in an extraction device outside the fermenter, and then the extracting agent is returned to the fermenter from which it was separated. 8) The manufacturing method according to claim 7, wherein the separated extractant is recovered and recycled. 9) The production method according to claim 5 or 8, wherein the temperature of the fermentation liquor is controlled by using a recirculating extraction agent as a heating medium.