JP6696776B2 - Fermentation apparatus and method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a fermentation apparatus and a fermentation method, and more particularly, to an apparatus and a method for performing fermentation treatment such as fermentation production and fermentation decomposition of organic matter by microorganisms in a liquid.

  Patent Document 1 discloses a system in which ethanol or the like is fermentatively produced and taken out from biomass. The remaining liquid after removal is subjected to wastewater recycling treatment, and the water is used as a pre-liquid for ethanol fermentation. It is described that when the pH is out of the range, the pH is adjusted by an acid or alkali neutralizing agent.

JP, 2004-121055, A

In the above-mentioned patent document, the neutralizing agent is added as needed, but the added neutralizing agent is often not removable by this treatment, and the neutralizing agent may accumulate in the system, which may adversely affect the culture and the like. There is.
In view of the above circumstances, it is an object of the present invention to reduce the required amount of a neutralizing agent in a fermentation apparatus, and to suppress or prevent the neutralizing agent from accumulating in the system.

To solve the above problems, the device of the present invention is a fermentation device for fermenting an organic matter by a microorganism in a liquid,
A production means comprising at least one main fermentor for fermentatively producing valuable organic matter by microorganisms in the culture broth;
Extraction means for extracting the valuable organic matter from the culture solution taken out from the production means,
Decomposition means for fermenting and decomposing the residual organic matter in the liquid after the extraction by microorganisms,
Measuring means for measuring the pH of the culture solution in the main fermenter,
Liquid sending means for sending a part of the liquid to the main fermenter from one or more locations from the extraction means to the outlet of the decomposition means,
Control means for controlling the liquid flow rate of the liquid supply means based on the measured pH value.
The method of the present invention is a fermentation method of fermenting an organic matter by a microorganism in a liquid,
A production process in which valuable organic matter is fermented and produced by microorganisms in the culture solution,
An extraction step of extracting the valuable organic matter from the culture solution after the production step,
A decomposition step of fermenting and decomposing the residual organic matter in the liquid after the extraction step with a microorganism,
A measuring step of measuring the pH of the culture solution in the producing step,
A liquid feeding step of sending a part of the liquid at one or a plurality of time points from the extraction step to after the decomposition step to the generation step,
And a control step of controlling the liquid supply flow rate of the liquid supply step based on the measured pH value.

  Usually, the pH of the liquid after extraction and the liquid during or after decomposition is different from the pH of the culture liquid in the production means (production step). The pH of the culture solution can be adjusted by mixing these solutions having different pHs with the culture solution instead of the neutralizing agent. This makes it possible to reduce the addition amount of the neutralizing agent or to eliminate the need for adding the neutralizing agent. Therefore, the accumulation of the neutralizing agent in the system can be suppressed or prevented. In addition, the recycling rate of the culture solution can be increased, and the supply flow rate of the stock solution of the culture solution can be reduced.

It is preferable that the liquid feeding means is connected to one or a plurality of locations of the outlet portion of the extraction means, the inlet portion, the midway portion, and the outlet portion of the decomposition means.
After the extraction step and before the decomposition step, and during or after the decomposition step, part of the liquid at one or more time points may be sent to the generation step while controlling the flow rate based on the measured pH value. preferable.
With this, the pH of the culture solution can be adjusted to a desired value.

It is preferable that the decomposition means includes an acid fermentation tank connected to the extraction means, and a methane fermentation tank provided on the downstream side of the acid fermentation tank. It is preferable that the liquid feeding means is connected to at least one position between the acid fermentation tank and the methane fermentation tank and the outlet of the methane fermentation tank.
It is preferable that the decomposition step includes an acid fermentation step of acid-fermenting the liquid after the extraction step and a methane fermentation step of methane-fermenting the liquid after the acid fermentation step. After the acid fermentation step and before the methane fermentation step, and after one or both of the methane fermentation step, a part of the liquid is sent to the production step while controlling the flow rate based on the measured pH value. Preferably.
This ensures that the pH of the culture broth can be adjusted to the desired value.

The decomposition means includes a reflux passage, the upstream end of the reflux passage is connected to the outlet of the methane fermentation tank, and the downstream end of the reflux passage is connected to the inlet of the acid fermentation tank. Is preferred.
It is preferable that the culture method further comprises a reflux step of mixing another part of the liquid after the methane fermentation with the liquid before the acid fermentation.
The liquid after methane fermentation has a higher pH than the liquid before acid fermentation. By returning this high pH liquid to the acid fermentation tank, it is possible to prevent the pH of the acid fermentation tank (liquid during the acid fermentation step) from becoming unnecessarily low. As a result, good acid fermentation can be performed without separately adding a neutralizing agent to the acid fermentation tank (liquid in the acid fermentation step). Since no separate neutralizing agent is needed, it does not accumulate.

The fermentation method further comprises a supply step of supplying a stock solution of the culture solution to the main fermenter,
In the control step, it is preferable to control the liquid supply flow rate and the stock solution supply flow rate based on the measured pH value.
This makes it possible not only to control the pH of the culture solution in the main fermenter (production step) to be desired, but also to keep the liquid supply flow rate to the main fermenter (production step) constant. As a result, the liquid flow rate flowing through the liquid flow path of the system can be kept constant.

The fermentation method, an addition step of adding a neutralizing agent to the culture solution of the production step and a separation and discharge step of separating and discharging solid matter from the liquid after the extraction step and before the decomposition step,
Further equipped with,
The decomposition step includes an anaerobic treatment step and an aerobic treatment step after the anaerobic treatment step,
The addition amount of the neutralizing agent is equal to the sum of the amount of the neutralizing agent in the discharge discharged in the separation and discharging step and the amount of the neutralizing agent in the liquid entering the aerobic treatment step. Preferably.
This makes it possible to more reliably prevent the neutralizing agent from accumulating in the system. Even if the liquid entering the aerobic treatment step contains ammonia or the like derived from the neutralizing agent, it can be decomposed by the aerobic treatment.

  According to the present invention, the required amount of the neutralizing agent can be reduced. As a result, accumulation of the neutralizing agent in the system can be suppressed or prevented.

FIG. 1 is a circuit diagram showing a schematic configuration of a fermentation apparatus according to the first embodiment of the present invention. FIG. 2 is a circuit diagram showing a schematic configuration of a fermentation apparatus according to the second embodiment of the present invention. FIG. 3 is a circuit diagram showing a schematic configuration of a fermentation apparatus according to the third embodiment of the present invention. FIG. 4 is a circuit diagram showing a schematic configuration of a fermentation apparatus according to the fourth embodiment of the present invention. FIG. 5: is a circuit diagram which shows schematic structure of the fermentation apparatus which concerns on 5th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 shows a fermentation apparatus 1 according to the first embodiment of the present invention. The fermentation apparatus 1 includes a stock solution supply means 2, a production means 10, an extraction means 20, a solid-liquid separation means 30, a decomposition means 40, and a liquid flow path 9 connecting these. The stock solution supply means 2, the generation means 10, the extraction means 20, the solid-liquid separation means 30, and the decomposition means 40 are arranged in this order along the flow direction of the liquid flow path 9. The liquid flow path 9 includes liquid paths 9a, 9b, 9c, 9d between two adjacent means 2, 10, 20, 30, 40, and liquid paths 9e, 9f, 9g inside and downstream of the decomposition means 40. Including.
Although illustration is omitted, a liquid feed pump is provided in each of the liquid paths 9a to 9g.

The stock solution 90 is stored in the stock solution supply means 2. Most of the stock culture solution 90 is water (H ₂ O). Nutrients such as vitamins and phosphoric acid are dissolved in this. The stock culture solution 90 is acidic.
The undiluted solution supply means 2 and the production means 10 are connected by a undiluted solution supply path 9a.

  The production means 10 comprises at least one main fermenter 11. The stock culture solution 90 from the stock solution supply means 2 is stored in the main fermentation tank 11 as a culture solution 91. An anaerobic microorganism for main fermentation is cultivated in the culture solution 91.

  Although not shown in detail, a substrate is supplied to the main fermentation tank 11. The substrate may be an organic substance or an inorganic substance as long as it is a substance that serves as an energy source for anaerobic microorganisms. The anaerobic microorganism for main fermentation fermentably produces organic substances such as ethanol and acetic acid from a substrate.

  The composition of the culture solution 91 is not the same as the composition of the culture stock solution 90, and contains components consumed by the metabolism of the main fermentation anaerobic microorganisms and components produced (such as ethanol and other fermentation products). There is. The culture solution 91 is weaker in acidity than the culture stock solution 90.

A neutralizer addition means 60 is attached to the main fermentation tank 11. The neutralizing agent adding means 60 includes a neutralizing agent source 61 and an adding path 62. The neutralizing agent source 61 stores alkaline neutralizing agents such as sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammonia (NH ₃ ). An addition path 62 from the neutralizing agent source 61 is connected to the main fermenter 11.

The generation means 10 and the extraction means 20 are connected by the culture solution delivery passage 9b.
The extraction means 20 includes one or a plurality of stages of distillation columns 21. A distillation vapor path 22 from the distillation column 21 at the final stage extends to a refining device (not shown). Further, the extraction residual liquid passage 9c from the bottom liquid outlet 23 extends to the solid-liquid separation means 30.

The solid-liquid separation means 30 includes, for example, a filter dehydrator 31. A solid matter discharge passage 34 extends from the filter dehydrator 31 to the outside of the system.
The liquid outlet of the solid-liquid separation means 30 and the decomposition means 40 are connected by the separated liquid passage 9d.

  The disassembling unit 40 includes an anaerobic treatment unit 41 and an aerobic treatment unit 44 (post-treatment unit). The anaerobic treatment unit 41 includes an acid fermentation tank 42 and a methane fermentation tank 43. The downstream end of the separated liquid passage 9d is connected to the acid fermentation tank 42. In the acid fermentation tank 42 (sub-fermentation tank), the liquid 93 (liquid for acid fermentation) after solid matter separation is stored. The acid fermentation bacterium is cultured in the acid fermentation target liquid 93 in the acid fermentation tank 42.

  The methane fermentation tank 43 is connected to the downstream side of the acid fermentation tank 42 in the decomposition means 40 via the acid fermentation completed liquid passage 9e. In the methane fermentation tank 43 (sub-fermentation tank), the liquid 94 (methane fermentation target liquid) after the acid fermentation treatment is stored. In the liquid 94 in the methane fermentation tank 43, methane-fermenting bacteria are cultivated.

  An aerobic treatment section 44 is provided on the downstream side of the methane fermentation tank 43 in the decomposition means 40. The methane fermentation tank 43 and the aerobic treatment section 44 are connected by the methane fermentation completed liquid passage 9f.

  The pH in the liquid flow path 9 is the lowest in the stock culture solution 90, and becomes higher in the order of the culture solution 91, the extraction residual solution 92, the solution 94 after the acid fermentation treatment, and the solution 95 after the methane fermentation treatment.

  The fermentation apparatus 1 further includes a pH adjusting means 50. The pH adjusting means 50 includes a liquid feeding means 51, a pH measuring device 55 (pH measuring means), and a controller 59 (controlling means). The liquid feeding means 51 has a liquid feeding passage 52 and a liquid feeding pump 53. The upstream end of the liquid supply path 52 is connected to the methane fermentation completed liquid path 9f (a middle part of the decomposition means 40). That is, the liquid feeding means 51 is connected to one location from the extraction means 20 to the outlet of the decomposition means 40. A part 95b of the liquid 95 after the methane fermentation treatment can be divided into the liquid supply path 52. A liquid feed pump 53 is provided in the middle of the liquid feed path 52. The downstream end of the liquid supply path 52 is connected to the stock solution supply path 9a, and in turn connected to the main fermentation tank 11.

  A pH meter 55 is connected to the main fermenter 11. The pH value of the culture solution 91 is measured by the pH measuring device 55. The output signal line of the pH measuring device 55 is connected to the controller 59. The control signal line of the controller 59 is connected to the liquid feed pump 53. The controller 59 includes a microcomputer and a drive circuit for the liquid feed pump 53.

Fermentation apparatus 1 operates as follows.
<Supply process>
The stock culture solution 90 is supplied to the main fermentation tank 11 from the stock solution supply means 2. The stock solution 90 is added to the culture solution 91 in the main fermentation tank 11.

<Production process (culture process)>
The anaerobic microorganism for main fermentation is cultivated in the culture solution 91 of the main fermenter 11. The anaerobic microorganism for main fermentation fermentatively produces valuable organic substances such as ethanol (C ₂ H ₅ OH). Acidic organic compounds such as acetic acid are also produced as by-products. Therefore, the pH of the culture solution 91 tends to be low.

<Addition process>
An appropriate amount of neutralizing agent is added to the culture solution 91 from the neutralizing agent adding means 60. As a result, it is possible to prevent the pH of the culture solution 91 from dropping more than necessary, and to promote the fermentation activity of the main fermentation anaerobic microorganism.

A part of the culture solution 91 in the main fermentation tank 11 is taken out to the culture solution delivery passage 9b and sent to the distillation column 21.
<Extraction process>
In the distillation column 21, the culture solution 91 is distilled to extract ethanol (valuable organic matter). The extracted ethanol is taken out from the distillate vapor path 22, further purified, and provided for various uses.

  The residual liquid 92 after extraction contains biomass such as a corpse of the anaerobic microorganisms for main fermentation and other residual organic substances (COD (Chemical Oxygen Demand) components). The post-extraction residual liquid 92 is sent to the filter dehydrator 31 through the extraction residual liquid passage 9c.

<Separation and discharge process>
In the filter dehydrator 31, the extraction residual liquid 92 is pressed and solid-liquid separated. The solid matter becomes a dehydrated cake state and is discharged from the solid matter discharge path 34 to the outside of the system. A part of the neutralizing agent is mixed in the discharge containing solid matter.
The liquid 93 after solid matter separation is sent to the decomposition means 40 through the separated liquid passage 9d.

<Disassembly process>
In the decomposing means 40, the anaerobic treatment unit 41 performs the anaerobic treatment process, and then the aerobic treatment unit 44 performs the aerobic treatment process. As the anaerobic treatment step, the acid fermentation step is first performed in the acid fermentation tank 42, and then the methane fermentation step is performed in the methane fermentation tank 43.

<Anaerobic treatment process-acid fermentation process>
In the acid fermentation tank 42, residual organic matter in the liquid 93 is decomposed by acid fermentation of the acid-fermenting bacteria. At this time, since the acid is generated, the pH of the acid fermentation tank 42 is lower than that of the methane fermentation tank 43.
The liquid 94 after the acid fermentation treatment is sent to the methane fermentation tank 43 through the acid fermentation completed liquid passage 9e.

<Anaerobic treatment process-Methane fermentation process>
In the methane fermentation tank 43, residual organic matter in the liquid 94 is decomposed by methane fermentation of methane-fermenting bacteria. At this time, since carbon dioxide gas and methane are generated, the pH of the methane fermentation tank 43 is relatively high.
COD can be reduced by an acid fermentation process and a methane fermentation process. Of the liquid 95 after the methane fermentation treatment, the liquid 95a excluding the reflux liquid 95b described below is sent to the aerobic treatment section 44 through the methane fermentation completed liquid passage 9f.

<Aerobic treatment process>
The aerobic treatment unit 44 aerobically decomposes the organic matter in the liquid 95a by aerobic microorganisms. This allows COD to be reduced to environmental emission standards. Even if the liquid 95a contains ammonia derived from the neutralizing agent from the neutralizing agent adding means 60, it can be decomposed by aerobic treatment.
<Liquid discharge process>
The waste liquid 96 after the aerobic treatment is discharged to the outside of the system as sewage by the waste liquid passage 9g. A part of the neutralizer is mixed in the waste liquid 96. This can prevent the neutralizing agent from accumulating in the system of the fermentation apparatus 1 in combination with the discharging of the neutralizing agent in the separation and discharging step and the decomposition by the aerobic treatment.

<Addition amount setting process>
Preferably, the sum of the flow rate Q ₃₄ of the neutralizing agent in the discharge from the solid matter discharge path 34 and the flow rate Q _95a of the neutralizing agent in the liquid 95a entering the aerobic treatment section 44 is the neutralizing agent addition. It is set so as to be substantially equal to the neutralizing agent addition flow rate Q _{60 of the} means 60.
Q ₃₄ + Q _{95a ≈Q 60} (Equation 1)
As a result, the amount of neutralizing agent in the fermenter 1 can be maintained in equilibrium. Further, the addition flow rate Q ₆₀ can be kept constant, and it is not necessary to feed back the pH value of the main fermentation tank 11 to the neutralizer addition means 60.

Further, the pH of the main fermenter 11 is adjusted by the pH adjusting means 50.
<Measuring process>
Specifically, the pH of the main fermenter 11 is measured by the pH measuring device 55. The measurement result is input to the controller 59.
<Control process>
The controller 59 controls the output of the liquid delivery pump 53 based on the pH measurement value of the pH measuring device 55.
<Liquid transfer process>
By driving the liquid feed pump 53, a part of the liquid 95 after the methane fermentation treatment (reflux liquid 95b) is diverted to the liquid feed path 52. Furthermore, the flow rate of the reflux liquid 95b is controlled by adjusting the output of the liquid feed pump 53. The reflux liquid 95b merges with the stock culture solution 90 from the stock solution supply means 2 in the stock solution supply passage 9a and is supplied to the main fermentation tank 11 together with the stock culture solution 90.

Here, the pH of the reflux liquid 95b is higher than the pH of the culture liquid 91 in the main fermenter 11. The pH of the stock culture solution 90 is lower than the pH of the reflux solution 95b, and further lower than the pH of the culture solution 91. Therefore, the pH of the culture solution 91 can be adjusted to a desired value by increasing or decreasing the flow rate of the reflux liquid 95b. That is, the pH of the main fermentation tank 11 can be adjusted by using the liquid in the liquid flow path 9 that is at a stage subsequent to the main fermentation tank 11. Thereby, the fermentation production of ethanol by the fermentative microorganisms in the culture medium 91 can be favorably and stably performed.
Moreover, since the reflux liquid 95b is instead of neutralizing agent can be sufficiently reduced supply flow rate Q ₆₀ neutralizing agent from the neutralizing agent adding means 60. Therefore, it is possible to more reliably suppress or prevent the accumulation of the neutralizing agent in the fermentation device 1.
Furthermore, by returning the liquid 95b to the main fermentation tank 11, the recycling rate of the culture liquid 91 can be increased. Therefore, the supply flow rate of the stock culture solution 90 can be reduced.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals will be given to the drawings for the contents overlapping with those of the above-described embodiments, and the description will be simplified.
[Second Embodiment]
FIG. 2 shows a second embodiment of the present invention.
In the fermenter 1B, the production means 10 includes a plurality (two in the figure) of main fermenters 11. These main fermenters 11, 11 are arranged in parallel with each other. The stock solution supply path 9a is branched into a plurality of parts and connected to each main fermentation tank 11. An addition path 62 is connected to each main fermentation tank 11. A culture solution delivery passage 9b is drawn out from each main fermentation tank 11. These culture solution delivery passages 9b, 9b join each other and are connected to the extraction means 20.

  The liquid supply path 52 of the liquid supply means 51 has a common path portion 52a and a plurality of individual path portions 52b and 52b. The common path portion 52a is branched from the methane-fermented liquid path 9f and extends. A plurality of individual road portions 52b and 52b are branched from the common road portion 52a. A liquid feed pump 53 is provided in each individual path portion 52b. The individual path portion 52b corresponds to the main fermentation tank 11 in a one-to-one correspondence. Each individual path portion 52b is connected to the corresponding main fermentation tank 11 via the corresponding stock solution supply path 9a.

  Each main fermentation tank 11 is provided with a pH measuring device 55. The output signal lines of these pH measuring devices 55 are connected to one controller 59. A plurality of control signal lines of the controller 59 are connected to the liquid feed pumps 53 of the corresponding individual path portions 52b.

  According to the fermenter 1B, the pH of the culture solution 91 is measured for each main fermentation tank 11, and the output of the corresponding liquid feed pump 53 is operated according to the measured value. As a result, the flow rate of the reflux liquid 95b in the corresponding individual passage portion 52b is adjusted. Thereby, the pH of each main fermentation tank 11 can be controlled to a desired value.

[Third Embodiment]
FIG. 3 shows a third embodiment of the present invention.
In the fermenter 1C, the control signal line of the controller 59 is connected not only to the liquid feed pump 53 but also to the stock solution supply pump 2P of the stock solution supply passage 9a. (Note that the stock solution supply pump 2P is also present in other embodiments (FIGS. 1-2 and 4-5), but the illustration thereof is omitted.)

According to the fermenter 1C, the controller 59 regulates the output of the liquid feed pump 53 and the output of the stock solution supply pump 2P. Therefore, the flow rate of the reflux solution 95b and the flow rate of the stock culture solution 90 can be adjusted, respectively, and the flow rate ratio of these solutions 95b and 90 can be adjusted to each other, and thus the pH after mixing can be adjusted. Thereby, the pH of the main fermenter 11 can be controlled more surely to be desired. Moreover, by maintaining the total flow rate of the liquids 95b and 90 constant, the liquid supply flow rate to the main fermentation tank 11 can be maintained constant. As a result, it is possible to maintain liquid flow path 9 the liquid flow rate through the (9 B to 9 f) constant.

[Fourth Embodiment]
As shown in FIG. 4, the upstream end of the liquid feeding means 51 may be connected not only to one location of the liquid flow path 9 (9c to 9f) from the extraction means 20 to the separation means 40 but also to a plurality of locations. .. A part of the liquids 92 to 95 at a plurality of time points from the extraction step to the decomposition step may be returned to the main fermentation tank 11.

  In the fermentation apparatus 1D of the fourth embodiment shown in FIG. 4, the liquid feeding means 51 includes two (plural) liquid feeding paths 52d and 52f. The liquid supply path 52d is branched from the separated liquid path 9d. That is, the upstream end of the liquid supply path 52d is connected between the solid-liquid separation means 30 and the decomposition means 40 (or the inlet portion of the decomposition means 40). Like the liquid feed passage 52 of the first embodiment, the liquid feed passage 52f is branched from the methane fermented liquid passage 9f so that the liquid feed passage 52f is connected to the outlet of the methane fermentation tank 43 (the middle portion of the decomposition means 40). There is.

  A liquid feed pump 53 is provided in each of the liquid feed paths 52d and 52f. The control signal line of the controller 59 is connected to each liquid delivery pump 53. The controller 59 controls the output of the two (plural) liquid feed pumps 53.

  The liquid feed paths 52d and 52f join together on the downstream side of the liquid feed pump 53 to form a common path 52c. The common path 52c is connected to the undiluted solution supply path 9a, which in turn is connected to the main fermentation tank 11.

  According to the fermenter 1D, a part (reflux liquid 93b) of the liquid 93 after solid-liquid separation (after the extraction process and before the decomposition process) is branched to the liquid supply path 52d, and at the same time, one part of the liquid 95 after the methane fermentation treatment is performed. The part (reflux liquid 95b) can be divided into the liquid supply path 52f. The pH of the reflux liquid 95b is higher than the pH of the reflux liquid 93b. Further, the controller 59 adjusts the output of the liquid feeding pump 53 of each of the liquid feeding paths 52d and 52f based on the pH measurement value of the main fermenter 11 measured by the pH measuring device 55. Thereby, the flow rates of the reflux liquids 93b and 95b can be adjusted, respectively, and the flow rate ratios of the reflux liquids 93b and 95b can be adjusted to each other, and further, the pH after mixing can be adjusted. The reflux liquids 93b and 95b join each other in the common passage 52c, and further join the culture stock solution 90 in the stock solution supply passage 9a, and are introduced into the main fermentation tank 11. Thereby, the pH of the main fermentation tank 11 can be controlled to a desired value.

[Fifth Embodiment]
FIG. 5 shows a fifth embodiment of the present invention.
In the fermenter 1E, the liquid feeding means 51 includes two (plural) liquid feeding paths 52e and 52f. The liquid supply path 52e is branched from the acid fermentation completed liquid path 9e. The upstream end of the liquid supply path 52e is connected between the acid fermentation tank 42 and the methane fermentation tank 43 (or the outlet of the acid fermentation tank 42). Like the liquid feed passage 52 of the first embodiment, the liquid feed passage 52f is connected to the outlet of the methane fermentation tank 43 by being branched from the methane fermented liquid passage 9f.

  A liquid feed pump 53 is provided in each of the liquid feed paths 52e and 52f. The control signal line of the controller 59 is connected to each liquid delivery pump 53. The controller 59 controls the output of the two (plural) liquid feed pumps 53.

  The liquid supply paths 52e and 52f join each other on the downstream side of the liquid supply pump 53 to form a common path 52c. The common path 52c is connected to the stock solution supply path 9a, which in turn is connected to the main fermentation tank 11.

  A reflux passage 45 is provided in the decomposition means 40 of the fermentation device 1E. The upstream end of the reflux passage 45 is connected to the methane fermentation completed liquid passage 9f, and further connected to the outlet of the methane fermentation tank 43. The downstream end of the reflux passage 45 is connected to the separated liquid passage 9d, and further connected to the inlet of the acid fermentation tank 42 (the inlet of the decomposing means 40).

  According to the fermenter 1E, a part of the liquid 94 after the acid fermentation treatment (reflux liquid 94b) is branched to the liquid feeding path 52e, and a part of the liquid 95 after the methane fermentation treatment (reflux liquid 95b) is fed. The flow can be diverted to the path 52f. The pH of the reflux liquid 95b is higher than the pH of the reflux liquid 94b. Further, the controller 59 adjusts the output of the liquid feed pump 53 of each of the liquid feed paths 52e and 52f based on the pH measurement value of the main fermenter 11 measured by the pH meter 55. Thereby, the flow rates of the reflux liquids 94b and 95b can be adjusted, respectively, and the flow rate ratios of the reflux liquids 94b and 95b can be adjusted to each other, and further, the pH after mixing can be adjusted. The reflux liquids 94b and 95b join each other in the common passage 52c and further join the culture stock solution 90 in the stock solution supply passage 9a and are introduced into the main fermenter 11. Thereby, the pH of the main fermentation tank 11 can be controlled to a desired value.

  Further, according to the fermenter 1E, another part of the liquid 95 after the methane fermentation treatment (another reflux liquid 95d) is branched to the reflux passage 45. The reflux liquid 95d is joined with the liquid 93 in the separated liquid passage 9d via the reflux passage 45 and returned to the acid fermentation tank 42. The pH of the reflux liquid 95d is higher than the pH of the acid fermentation target liquid 93. Therefore, it is possible to prevent the pH of the acid fermentation tank 42 from being lowered more than necessary. As a result, good acid fermentation can be maintained without separately adding a neutralizing agent to the acid fermentation tank 42. Since no separate neutralizing agent is needed, it does not accumulate.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the first embodiment (FIG. 1), the upstream end of the liquid supply path 52 may be connected to the portion of the liquid flow path 9 from the extraction means 20 to the outlet of the decomposition means 40, and the methane fermentation is completed. Not limited to the liquid passage 9f, the extraction residual liquid passage 9c (the outlet portion of the extraction means 20), the separated liquid passage 9d (the inlet portion of the separation means 40), the acid fermentation completed liquid passage 9e (the middle portion of the separation means 40), Alternatively, it may be connected to the waste liquid passage 9g (the outlet of the separating means 40). The liquid feeding means 51 replaces a part of the liquid 95 after the methane fermentation step with a part of the liquid 92 or 93 after the extraction step and before the separation step, during the separation step or after the acid fermentation step and before the methane fermentation step. A part of the liquid 94 or a part of the liquid 96 after the separation step may be sent to the main fermentation tank 11. The same applies to the second and third embodiments.

In the second embodiment (FIG. 2), the number (n) of the main fermentation tanks 11, 11 may be three or more (n ≧ 3). It is not always necessary to adjust the pH of all (n) main fermenters 11 by the pH adjusting means 50, and only a part (m, 1 ≦ m <n) of the main fermenters 11 may be adjusted by the pH adjusting means 50. You may decide to do it.
In the second embodiment (FIG. 2), the controller 59 may be provided for each of the pH meter 55 and the liquid feed pump 53.
In the second embodiment, a plurality of main fermenters 11, 11 may be connected in series with each other.

In the fourth embodiment (FIG. 4), the upstream end of the liquid supply path 52d may be connected to the liquid paths 9c, 9e, 9f instead of the liquid path 9d, and the upstream end of the liquid supply path 52f is Instead of the liquid passage 9f, it may be connected to the liquid passages 9d, 9e, 9g.
In the fifth embodiment (FIG. 5), the upstream end of the liquid supply path 52e may be connected to the liquid paths 9c, 9d, 9f instead of the liquid path 9e, and the upstream end of the liquid supply path 52f is Instead of the liquid passage 9f, it may be connected to the liquid passages 9d, 9e, 9g.
In the fourth and fifth embodiments (FIGS. 4 to 5), a part of the liquids 92 to 96 at three or more points between the extraction means 20 and the outlet of the decomposition means 40 is sent to the main fermentation tank 11. Good. That is, a part of the liquids 92 to 96 at three or more times from the extraction process to the decomposition process may be sent to the main fermentation tank 11.
When the extraction means 20 includes a plurality of distillation columns, a part of the liquid from the distillation column of one stage to the distillation column of the next stage may be sent to the main fermentation tank 11.

  The unique configurations of a plurality of embodiments may be combined. For example, in the second embodiment (FIG. 2) and the fifth embodiment (FIG. 5) as well as in the third embodiment (FIG. 3), the output of the stock solution supply pump 2P is also added in addition to the solution sending pump 53. You may control. Also in the first to third embodiments (FIGS. 1 to 3), the disassembling means 40 may be provided with the same reflux passage 45 as in the fifth embodiment (FIG. 5).

When the main fermentation tank 11 is alkaline, an acidic neutralizing agent such as acetic acid or lactic acid may be used as the neutralizing agent of the neutralizing agent adding means 60.
The valuable organic substance may be ethanol, butanol, acetic acid or acetate, and other organic compounds.

  INDUSTRIAL APPLICABILITY The present invention can be applied to, for example, an ethanol production system for synthesizing ethanol from carbon monoxide generated by incineration of industrial waste.

1 Fermentation apparatus 1B, 1C, 1D, 1E Fermentation apparatus 2 Undiluted solution supply means 2P Undiluted solution supply pump 9 Liquid passages 9a-9g Liquid passage 10 Generation means 11 Main fermentation tank 20 Extraction means 30 Solid-liquid separation means 34 Solids discharge passage 40 Decomposing means 41 Anaerobic treatment section 42 Acid fermentation tank 43 Methane fermentation tank 44 Aerobic treatment section 45 Reflux passage 50 pH adjusting means 51 Liquid feeding means 52 Liquid feeding passage 53 Liquid feeding pump 55 pH measuring device (measuring means)
59 controller (control means)
60 Neutralizing agent adding means 52d, 52e, 52f Liquid feeding path 90 Culture stock solution 91 Culture solution 92 Residual solution after extraction (solution after extraction step and before separation step)
93b Reflux liquid (part of liquid after extraction step and before separation step)
94b Reflux liquid (part of the liquid during the separation process (after the acid fermentation process and before the methane fermentation process))
95d Other reflux liquid (other part of liquid after methane fermentation process)
92a Liquid entering the aerobic treatment part (aerobic treatment process) 95b Reflux liquid (part of the liquid during the separation process (after the methane fermentation process))
96 Waste liquid (liquid at the outlet of the separation process)

Claims (10)

In a fermenter for fermenting organic matter by microorganisms in the liquid,
A production means comprising at least one main fermentor for fermentatively producing valuable organic matter by microorganisms in the culture broth;
An undiluted solution supply path connecting the undiluted solution supply means and the production means of the culture solution,
A stock solution supply pump provided in the stock solution supply path,
Extraction means for extracting the valuable organic matter from the culture solution taken out from the production means,
Decomposition means for fermenting and decomposing the residual organic matter in the liquid after the extraction by microorganisms,
Measuring means for measuring the pH of the culture solution in the main fermenter,
Liquid feeding means including a liquid feeding path and a liquid feeding pump for feeding a part of the liquid as a reflux liquid from one or a plurality of locations from the extraction means to the outlet of the decomposition means to the main fermentation tank,
Control for controlling the liquid feed pump and the stock solution supply pump so that the pH in the main fermentation tank becomes predetermined based on the measured pH value and the total flow rate of the reflux liquid and the stock solution becomes constant. And a fermentation device.   The upstream end of the liquid feeding means is connected to one or a plurality of locations of the outlet portion of the extraction means and the inlet portion, the midway portion, and the outlet portion of the decomposition means. The described fermentation device. The decomposition means includes an acid fermentation tank connected to the extraction means, and a methane fermentation tank provided on the downstream side of the acid fermentation tank,
The fermentation according to claim 1, characterized in that the liquid feeding means is connected to at least one of the outlet between the acid fermentation tank and the methane fermentation tank and the outlet of the methane fermentation tank. apparatus.   The decomposition means includes a reflux passage, the upstream end of the reflux passage is connected to the outlet of the methane fermentation tank, and the downstream end of the reflux passage is connected to the inlet of the acid fermentation tank. The fermentation device according to claim 3, wherein In the fermentation method of fermenting organic matter by the microorganisms in the liquid,
A production process in which valuable organic matter is fermented and produced by microorganisms in the culture solution,
A supply step of supplying a stock solution of the culture solution to the production step,
An extraction step of extracting the valuable organic matter from the culture solution after the production step,
A decomposition step of fermenting and decomposing the residual organic matter in the liquid after the extraction step with a microorganism,
A measuring step of measuring the pH of the culture solution in the producing step,
A liquid feeding step of sending a part of the liquid at one or more time points from the extraction step to after the decomposition step to the production step as a reflux liquid ,
Based on the measured value of the pH, the pH of the culture solution in the producing step becomes predetermined, and the total flow rate of the reflux solution and the stock solution becomes constant, so that the flow rate of the reflux solution and the stock solution And a control step of controlling a supply flow rate . The reflux liquid, together with the stock solution is combined with the stock solution, the fermentation method according to claim 5, characterized that you supply to the main fermenter for performing said generating step.   After the extraction step and before the decomposition step, and during or after the decomposition step, a part of the liquid at one or more time points is sent to the generation step while controlling the flow rate based on the measured pH value. The fermentation method according to claim 5 or 6, which is characterized in that. The decomposition step includes an acid fermentation step of acid-fermenting the liquid after the extraction step, and a methane fermentation step of methane-fermenting the liquid after the acid fermentation step,
After the acid fermentation step and before the methane fermentation step, and after one or both of the methane fermentation step, a part of the liquid is sent to the production step while controlling the flow rate based on the measured pH value. The fermentation method according to claim 5 or 6, characterized in that   The fermentation method according to claim 8, further comprising a reflux step of mixing another part of the liquid after the methane fermentation step with the liquid before the acid fermentation step. An adding step of adding a neutralizing agent to the culture solution of the producing step, and a separating and discharging step of separating and discharging a solid matter from the liquid after the extracting step and before the decomposing step,
Further equipped with,
The decomposition step includes an anaerobic treatment step and an aerobic treatment step after the anaerobic treatment step,
The addition amount of the neutralizing agent is equal to the sum of the amount of the neutralizing agent in the discharge discharged in the separation and discharging step and the amount of the neutralizing agent in the liquid entering the aerobic treatment step. The fermentation method according to any one of claims 5 to 9, wherein the fermentation method is performed.

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