An anaerobic bacteria fermentation system and a fermentation method

Abstract

The present invention particularly relates to an anaerobic bacteria fermentation system and a fermentation method, belonging to the field of fermentation control. An anaerobic bacteria fermentation system includes: a fermentation container for carrying out fermentation, the fermentation container is provided with a first mash inlet, a mash outlet, a nitrogen inlet and a tail gas outlet; a sterilization container for carrying out sterilization, the sterilization container is provided with a second mash inlet, an air inlet and an air outlet, and the second mash inlet is used for communicating with the mash outlet. It can effectively solve the technical problem that when using carbon monoxide as a carbon source to ferment Clostridium ethanoligenum, the product will spontaneously acidify.

Description

Technical Field

[0001] The present invention belongs to the field of fermentation control, and particularly relates to an anaerobic bacteria fermentation system and a fermentation method. Background Art

[0002] Clostridium autoethanogenum is a strict anaerobic bacterium. When using carbon monoxide as a microbial carbon source for strict anaerobic fermentation, the mature mash obtained after fermentation will spontaneously acidify without human intervention, resulting in a significant reduction in the yield of the target product ethanol. Summary of the Invention

[0003] The purpose of the present application is to provide an anaerobic bacteria fermentation system and a fermentation method to solve the technical problem that when using carbon monoxide as a carbon source to ferment Clostridium autoethanogenum, the product will spontaneously acidify.

[0004] An embodiment of the present invention provides a fermentation system, including: a fermentation container for performing fermentation, the fermentation container being provided with a first mash inlet, a mash outlet, a nitrogen inlet, and a tail gas outlet; a sterilization container for performing sterilization, the sterilization container being provided with a second mash inlet, an air inlet, and an air outlet, and the second mash inlet being used to communicate with the mash outlet.

[0005] Optionally, the first mash inlet is provided at the top of the fermentation container, and the nitrogen inlet is provided at the bottom of the fermentation container; the second mash inlet is provided at the top of the sterilization container, and the air inlet is provided at the bottom of the sterilization container.

[0006] Optionally, a first annular pipe is provided at the inner bottom of the fermentation container, the first annular pipe is communicated with the nitrogen inlet through an inlet, and a plurality of first air outlet holes are opened on the first annular pipe; a second annular pipe is provided at the inner bottom of the sterilization container, the second annular pipe is communicated with the air inlet through an inlet, and a plurality of second air outlet holes are opened on the second annular pipe.

[0007] Optionally, a plurality of the first air outlet holes are evenly distributed on the top surface of the first annular pipe; a plurality of the second air outlet holes are evenly distributed on the top surface of the second annular pipe.

[0008] Optionally, the fermentation container is provided with a first circulation pipeline, one end of the first circulation pipeline is communicated with the bottom of the fermentation container, and the other end is communicated with the top of the fermentation container, and a first circulation pump is provided on the first circulation pipeline; the sterilization container is provided with a second circulation pipeline, one end of the second circulation pipeline is communicated with the bottom of the sterilization container, and the other end is communicated with the top of the sterilization container, and a second circulation pump is provided on the second circulation pipeline.

[0009] Optionally, a first atomizer is connected to the top end of the first circulation pipeline, and a second atomizer is connected to the top end of the second circulation pipeline.

[0010] Optionally, it further includes: a heat exchanger, which is provided with a heat exchange inlet, a heat exchange outlet, a medium inlet and a medium outlet. The heat exchange inlet is communicated with the mash outlet, and the heat exchange outlet is communicated with the second mash inlet through a liquid supply pipe.

[0011] Optionally, a two-way valve is connected to the liquid supply pipe. One outlet of the two-way valve is communicated with the second mash inlet, and the other outlet is communicated with a bypass pipe. The bypass pipe is communicated with the top of the fermentation container. A temperature sensor is provided on the liquid supply pipe, and the temperature sensor is electrically connected to the control system of the two-way valve.

[0012] Based on the same inventive concept, an embodiment of the present invention further provides a fermentation method, including the following steps:

[0013] Using carbon monoxide as a microbial carbon source, anaerobic fermentation of Clostridium autoethanogenum is carried out to obtain mash.

[0014] Using nitrogen to displace the residual carbon monoxide in the mash to obtain a displaced mash.

[0015] Using compressed air to aerate the displaced mash to obtain a sterilized mash.

[0016] Optionally, it further includes the following steps:

[0017] Heating the displaced mash to 65-70 °C, and then carrying out the aeration.

[0018] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0019] The fermentation system provided by the embodiment of the present invention implements anaerobic fermentation of Clostridium autoethanogenum using carbon monoxide as a carbon source by setting a fermentation container to obtain mash containing ethanol. By setting a nitrogen inlet, nitrogen is used to displace the residual carbon monoxide in the mash to prevent the residual carbon monoxide from being utilized by Clostridium autoethanogenum to preferentially ferment and produce acetic acid, avoiding acidification of the mash. By setting a sterilization container and an air inlet, the mash is sterilized. Compressed air is introduced through the air inlet, and the displaced mash is aerated with air. The oxygen in the compressed air is used to inhibit and kill Clostridium autoethanogenum, effectively sterilizing the mash containing ethanol.

[0020] The above description is only an overview of the technical solutions of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specifically illustrates the specific embodiments of the present invention. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of an anaerobic fermentation system provided by an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the first annular pipe of the anaerobic fermentation system provided by an embodiment of the present invention;

[0024] Figure 3 It is a schematic diagram of the second annular pipe of the anaerobic fermentation system provided by an embodiment of the present invention;

[0025] Figure 4 It is a flowchart of the method provided by an embodiment of the present invention.

[0026] Reference numerals:

[0027] 10 - fermentation container; 11 - first mash inlet; 12 - mash outlet; 13 - tail gas outlet; 14 - first annular pipe; 141 - first air outlet hole; 15 - first circulation pipeline; 151 - first circulation pump; 152 - first atomizer; 16 - nitrogen inlet; 20 - sterilization container; 21 - second mash inlet; 22 - air inlet; 23 - air outlet; 24 - second annular pipe; 241 - second air outlet hole; 25 - second circulation pipeline; 251 - second circulation pump; 252 - second atomizer; 30 - heat exchanger; 31 - heat exchange inlet; 32 - heat exchange outlet; 321 - liquid supply pipe; 322 - bypass pipe; 323 - two-way valve; 324 - temperature sensor; 33 - medium inlet; 34 - medium outlet. Detailed embodiments

[0028] The following will specifically describe the present invention in combination with the detailed embodiments and examples, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these detailed embodiments and examples are used to illustrate the present invention, rather than to limit the present invention.

[0029] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as the general understanding of those skilled in the art to which the present invention belongs. In case of contradiction, this specification shall prevail. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. For example, room temperature can refer to the temperature within the range of 10 - 35 °C.

[0030] Unless otherwise specified, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0031] The technical solution of the embodiment of the present application for solving the above technical problems has the following general idea:

[0032] According to a typical embodiment of the present invention, please refer to Figure 1 and Figure 2 , a fermentation system is provided, including: a fermentation vessel 10 for performing fermentation, the fermentation vessel 10 is provided with a first mash inlet 11, a mash outlet 12, a nitrogen inlet 16, and a tail gas outlet 13; a sterilization vessel 20 for performing sterilization, the sterilization vessel 20 is provided with a second mash inlet 21, an air inlet 22, and an air outlet 23, and the second mash inlet 21 is used to communicate with the mash outlet 12. By setting the fermentation vessel 10, anaerobic fermentation of Clostridium autoethanogenum using carbon monoxide as a carbon source is carried out to obtain a mash containing ethanol. By setting the nitrogen inlet 16, nitrogen is used to displace the residual carbon monoxide in the mash, preventing the residual carbon monoxide from being utilized by Clostridium autoethanogenum and preferentially fermenting to produce acetic acid, thus avoiding mash acidification; by setting the sterilization vessel 20 and the air inlet 22, the mash is sterilized, compressed air is introduced through the air inlet 22, and the replaced mash is aerated with air, and the oxygen in the compressed air is used to inhibit and kill Clostridium autoethanogenum, effectively sterilizing the mash containing ethanol.

[0033] As an alternative embodiment, the first mash inlet 11 is provided at the top of the fermentation vessel 10, and the nitrogen inlet 16 is provided at the bottom of the fermentation vessel 10; the second mash inlet 21 is provided at the top of the sterilization vessel 20, and the air inlet 22 is provided at the bottom of the sterilization vessel 20. Through the above settings, the mash and nitrogen, and the mash and compressed air are both in a convective contact manner for displacement and aeration, effectively improving the contact efficiency and reaction efficiency.

[0034] As an alternative embodiment, a first annular pipe 14 is provided at the inner bottom of the fermentation vessel 10, the first annular pipe 14 is connected to the nitrogen inlet 16 through an inlet, and the first annular pipe 14 is provided with a plurality of first air outlet holes 141; a second annular pipe 24 is provided at the inner bottom of the sterilization vessel 20, the second annular pipe 24 is connected to the air inlet 22 through an inlet, and the second annular pipe 24 is provided with a plurality of second air outlet holes 241. By setting the first annular pipe 14 and the second annular pipe 24, the contact area and contact uniformity between nitrogen and compressed air and the mash are effectively increased, thereby further optimizing the efficiency of displacement and aeration.

[0035] Preferably, a plurality of the first air outlets 141 are evenly distributed on the top surface of the first annular pipe 14; a plurality of the second air outlets 241 are evenly distributed on the top surface of the second annular pipe 24.

[0036] As an alternative embodiment, the fermentation container 10 is provided with a first circulation pipeline 15. One end of the first circulation pipeline 15 is communicated with the bottom of the fermentation container 10, and the other end is communicated with the top of the fermentation container 10. The first circulation pipeline 15 is provided with a first circulation pump 151; the sterilization container 20 is provided with a second circulation pipeline 25. One end of the second circulation pipeline 25 is communicated with the bottom of the sterilization container 20, and the other end is communicated with the top of the sterilization container 20. The second circulation pipeline 25 is provided with a second circulation pump 251. By providing the first circulation pipeline 15 and the second circulation pipeline 25, the mash is circulated from the bottom of the container to the top of the container by using the first circulation pump 151 and the second circulation pump 251 respectively, so that the mash is displaced and aerated with nitrogen and compressed air through multiple circulations, thereby improving the efficiency and completion rate of displacement and aeration.

[0037] As an alternative embodiment, a first atomizer 152 is connected to the top end of the first circulation pipeline 15, and a second atomizer 252 is connected to the top end of the second circulation pipeline 25. By providing the first atomizer 152 and the second atomizer 252, the circulated mash is broken up, further increasing the contact area between the mash and the gas, and further improving the efficiency and effect of displacement and aeration.

[0038] As an alternative embodiment, it further includes: a heat exchanger 30. The heat exchanger 30 is provided with a heat exchange inlet 31, a heat exchange outlet 32, a medium inlet 33 and a medium outlet 34. The heat exchange inlet 31 is communicated with the mash outlet 12, and the heat exchange outlet 32 is communicated with the second mash inlet 21 through a liquid supply pipe 321. By providing the heat exchanger 30, the displaced mash is heated to prevent some acid-producing miscellaneous bacteria (such as acetic acid bacteria) that grow at medium temperature from contaminating the mash. By adjusting the heating temperature, the above-mentioned miscellaneous bacteria that grow at medium temperature can be effectively killed.

[0039] It should be noted that in this actual example, hot steam is used for heat exchange to heat the displaced mash. In other embodiments, other heating devices can also be used for heating, as long as the miscellaneous bacteria can be killed and the quality of the ethanol clostridium and the mash is not affected.

[0040] As an alternative embodiment, the liquid supply pipe 321 is connected to a two-way valve 323. One outlet of the two-way valve 323 is connected to the second mash inlet 21, and the other outlet is connected to a bypass pipe 322. The bypass pipe 322 is connected to the top of the fermentation vessel 10. The liquid supply pipe is provided with a temperature sensor 324, and the temperature sensor 324 is electrically connected to the control system of the two-way valve 323. With the above arrangement, when the temperature sensor 324 detects that the temperature of the mash heated by the heat exchanger 30 is insufficient, the two-way valve 323 is controlled to open the outlet communicating with the bypass pipe 322 and close the outlet communicating with the second mash inlet 21, and the mash is pumped back into the fermentation vessel 10, so as to perform secondary heating by means of the heat exchanger 30.

[0041] According to another typical embodiment of the present invention, a fermentation method is provided, which includes the following steps:

[0042] S1. Use carbon monoxide as the microbial carbon source to perform anaerobic fermentation of Clostridium autoethanogenum to obtain mash.

[0043] S2. Use nitrogen to displace the residual carbon monoxide in the mash to obtain a displaced mash.

[0044] S3. Aerate the displaced mash with compressed air to obtain a sterilized mash.

[0045] As an alternative embodiment, it further includes the following steps:

[0046] S2.1. Heat the displaced mash to 65 - 70 °C, and then perform the aeration.

[0047] Finally, it should also be noted that the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or apparatus.

[0048] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0049] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method of fermentation using a fermentation system, characterized in that, It includes the following steps: Using carbon monoxide as a microbial carbon source, anaerobic fermentation of Clostridium autoethanogenum is carried out to obtain mash; Using nitrogen to displace the residual carbon monoxide in the mash to obtain a displaced mash; Aerating the displaced mash with compressed air to obtain a sterilized mash; The fermentation system includes: A fermentation vessel (10), the fermentation vessel (10) is provided with a first mash inlet (11), a mash outlet (12), a nitrogen inlet (16) and a tail gas outlet (13), and the first mash inlet is used to introduce the mash containing ethanol obtained by anaerobic fermentation of Clostridium autoethanogenum using carbon monoxide as a carbon source; A sterilization vessel (20) for sterilizing the mash, the sterilization vessel (20) is provided with a second mash inlet (21), an air inlet (22), and an air outlet (23), and the second mash inlet (21) is used to communicate with the mash outlet (12); A heat exchanger (30), the heat exchanger (30) is provided with a heat exchange inlet (31), a heat exchange outlet (32), a medium inlet (33) and a medium outlet (34), the heat exchange inlet (31) communicates with the mash outlet (12), the heat exchange outlet (32) is connected to the second mash inlet (21) through a liquid supply pipe (321), and the heat exchanger (30) is used to heat the displaced mash to avoid contamination of the mash by some acid-producing miscellaneous bacteria that grow at medium temperatures; The first mash inlet (11) is provided at the top of the fermentation vessel (10), and the nitrogen inlet (16) is provided at the bottom of the fermentation vessel (10); the second mash inlet (21) is provided at the top of the sterilization vessel (20), and the air inlet (22) is provided at the bottom of the sterilization vessel (20); A first annular pipe (14) is provided at the inner bottom of the fermentation vessel (10), the first annular pipe (14) is connected to the nitrogen inlet (16) through an inlet, and the first annular pipe (14) is provided with a plurality of first air holes (141); a second annular pipe (24) is provided at the inner bottom of the sterilization vessel (20), the second annular pipe (24) is connected to the air inlet (22) through an inlet, and the second annular pipe (24) is provided with a plurality of second air holes (241); The fermentation vessel (10) is provided with a first circulation pipeline (15), one end of the first circulation pipeline (15) is connected to the bottom of the fermentation vessel (10), and the other end is connected to the top of the fermentation vessel (10), and the first circulation pipeline (15) is provided with a first circulation pump (151); the sterilization vessel (20) is provided with a second circulation pipeline (25), one end of the second circulation pipeline (25) is connected to the bottom of the sterilization vessel (20), and the other end is connected to the top of the sterilization vessel (20), and the second circulation pipeline (25) is provided with a second circulation pump (251).

2. The method according to claim 1, characterized in that, A plurality of the first air holes (141) are evenly distributed on the top surface of the first annular pipe (14); a plurality of the second air holes (241) are evenly distributed on the top surface of the second annular pipe (24).

3. The method according to claim 1, characterized in that The top end of the first circulation pipeline (15) is connected to a first atomizer (152), and the top end of the second circulation pipeline (25) is connected to a second atomizer (252).

4. The method according to claim 1, characterized in that The liquid supply pipe (321) is connected with a two-way valve (323). One outlet of the two-way valve (323) is communicated with the second mash inlet (21), and the other outlet is communicated with a bypass pipe (322). The bypass pipe (322) is communicated with the top of the fermentation vessel (10). The liquid supply pipe is provided with a temperature sensor (324), and the temperature sensor (324) is electrically connected with the control system of the two-way valve (323).

5. The method according to claim 1, characterized in that, The following steps are further included: Heat the replacement mash to 65 - 70 °C, and then perform the aeration.

Images