A device and method for controlling gas content in a gas fermentation

Abstract

The application discloses a kind of control device and control method of gas content in gas fermentation, it is related to the technical field of biological fermentation alcohol, solve the technical problem that fermentation mash gas content is not easy to stable control in relevant technology.Control device includes reactor system, production water inlet system, background antifoam additive system, conventional defoaming agent adding system, emergency defoaming agent adding system and control center, control center is connected with first gas content detector, second gas content detector, production water flowmeter, production water regulating valve, antifoam agent flowmeter, antifoam agent regulating valve, conventional defoaming agent flowmeter, conventional defoaming agent regulating valve, fast defoaming agent adding pump and fast defoaming agent switch valve all signal connection, when the first gas content detector data is abnormal, control conventional defoaming agent feed, when the second gas content detector data is abnormal, control fast defoaming agent feed.This device is more conducive to the stable regulation and control of fermentation mash gas content in target range.

Description

Technical Field

[0001] This invention relates to the field of bio-fermentation alcohol production technology, and in particular to a device and method for controlling the gas content in gaseous fermentation. Background Technology

[0002] Syngas bio-fermentation to alcohol production is a continuous fermentation process in a bioreactor. The gas content of the fermentation mash is an important parameter for fermentation operation and a key factor affecting gas utilization. If the gas content of the fermentation mash is controlled too low, the gas-liquid mass transfer effect will be poor, directly leading to a decrease in gas utilization and waste of raw materials. If the gas content of the fermentation mash is controlled too high, the probability of frequent foaming and liquid escape in the fermentation liquid will be too high, which will not only cause a large number of microorganisms to die, but also cause waste and environmental pollution.

[0003] The gas content of fermentation mash is usually controlled by adding defoamers, mainly through manual intermittent or automatic continuous addition. However, the amount added is often insufficient or excessive, which cannot meet the need for stable gas content of fermentation mash in the continuous industrial production of syngas fermentation. Summary of the Invention

[0004] This application provides a device and method for controlling the gas content in gas fermentation, which solves the technical problem that the gas content of fermentation mash is not easy to control stably in related technologies.

[0005] This application provides a device for controlling gas holdup in gas fermentation, comprising a reactor system, a production water inlet system, a background defoamer addition system, a conventional defoamer addition system, an emergency defoamer addition system, and a control center. The reactor system includes a bioreactor, a spray pipe installed at the top of the bioreactor, and a first gas holdup detector and a second gas holdup detector internally located within the bioreactor, with the first gas holdup detector being lower than the second gas holdup detector. The production water inlet system includes a production water inlet pipeline and a production water flow meter installed on the production water inlet pipeline, the production water inlet pipeline being connected to the lower part of the bioreactor. The background defoamer addition system includes a defoamer addition pipeline and a defoamer storage tank installed on the defoamer addition pipeline, one end of the defoamer addition pipeline being connected to the bioreactor, and this connection point being lower than the first gas holdup detector. The system includes: a conventional defoamer addition system (comprising a conventional defoamer addition pipeline and a conventional defoamer storage tank installed on the pipeline, with the pipeline connected to the spray pipe); an emergency defoamer addition system (comprising an emergency defoamer addition pipeline and a rapid defoamer storage tank installed on the pipeline, with the pipeline connected to the spray pipe); and a control center connected to the first gas holdup detector, the second gas holdup detector, and the production water flow meter. The control center uses data from the production water flow meter to control the defoamer addition flow rate in the defoamer storage tank. In case of abnormal data from the first gas holdup detector, the control center controls the addition of conventional defoamer to the conventional defoamer storage tank. In case of abnormal data from the second gas holdup detector, the control center controls the addition of rapid defoamer to the conventional defoamer storage tank, ensuring that the gas holdup in the bioreactor returns to within the limit range.

[0006] In some implementations, the production water inlet system also includes a production water regulating valve installed on the production water inlet pipeline; The background defoamer addition system also includes a defoamer addition pump, a defoamer flow meter, and a defoamer regulating valve installed on the defoamer addition pipeline; The conventional defoamer addition system also includes a conventional defoamer addition pump, a conventional defoamer flow meter, and a conventional defoamer regulating valve installed on the conventional defoamer addition pipeline; The emergency defoamer dosing system also includes a rapid defoamer dosing pump, a dosing tank, and a rapid defoamer on / off valve installed on the emergency defoamer dosing pipeline; The control center is connected to the first gas content detector, the second gas content detector, the production water flow meter, the production water regulating valve, the defoamer flow meter, the defoamer regulating valve, the conventional defoamer flow meter, the conventional defoamer regulating valve, the rapid defoamer addition pump, and the rapid defoamer switch valve.

[0007] In some implementations, both the defoamer addition pump and the conventional defoamer addition pump include variable frequency pumps, while the rapid defoamer addition pump includes a fixed frequency pump.

[0008] In some implementations, the connection point between the defoamer addition line and the bioreactor is higher than the bioreactor's vent.

[0009] In some implementations, the connection between the defoamer addition pipeline and the bioreactor is 0.2-4m higher than the aeration port of the bioreactor; The first gas content detector is 0.2-4m higher than the connection between the defoamer addition pipeline and the bioreactor; The second gas content detector is 0.5-4m lower than the liquid level inside the bioreactor.

[0010] In some embodiments, the defoamer addition pipeline is also equipped with a first self-controlled switching valve and a first check valve; The conventional defoamer addition pipeline is also equipped with a second automatic control switch valve and a second check valve; The emergency defoamer addition line is also equipped with a third check valve; The production water inlet pipeline is also equipped with a third automatic control switch valve.

[0011] In some implementations, the control limit for the first gas holdup detector is 0.15-0.25; and the control limit for the second gas holdup detector is 0-0.3.

[0012] In some embodiments, the reactor system also includes a gas-liquid separator installed on the top tail gas line of the bioreactor. The gas-liquid separator is equipped with a gas-liquid separator level gauge, which is signal-connected to a control center. The control center controls the feeding of a rapid defoamer when the gas-liquid separator level gauge data is abnormal.

[0013] In some implementations, the control limit of the gas-liquid separator level gauge is any value in the range of 0-0.1m.

[0014] A method for controlling gas content during gas fermentation, employing the aforementioned control device, includes the following control method: Under continuous operation of the bioreactor, the production water inlet system supplies water to the bioreactor, and the control center controls the addition flow rate of the defoamer addition pipeline based on the detection data of the production water flow meter. Under continuous operation of the bioreactor, the control center controls the flow rate of the conventional defoamer addition pipeline based on the detection data of the first gas content detector. Under conditions of continuous operation of the bioreactor, the control center controls the addition of emergency defoamer via the pipeline based on the detection data from the second gas content detector.

[0015] The beneficial effects of this application are as follows: It provides a device for controlling the gas content in gas fermentation, including a reactor system, a production water inlet system, a background defoamer addition system, a conventional defoamer addition system, an emergency defoamer addition system, and a control center. This device regulates the gas content of the fermentation mash by combining the background defoamer addition system, the conventional defoamer addition system, and the emergency defoamer addition system. The control center continuously adjusts the injection amounts of defoamer, conventional defoamer, and emergency defoamer based on relevant data, thereby stabilizing the gas content of the fermentation mash within the target range in the bioreactor and maintaining a stable environment with good gas-liquid contact within the bioreactor. This ensures high gas utilization and stable operation of the fermentation system during syngas bio-fermentation for alcohol production. Since the device is primarily regulated by the control center, it reduces the errors associated with manual intermittent or automatic continuous addition of defoamers, making it more effective in stabilizing the gas content of the fermentation mash within the target range and also reducing labor intensity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0017] Figure 1 This is a schematic diagram of a gas content control device for gas fermentation provided in this application.

[0018] Attached diagram labels: 1- Defoamer addition pipeline, 2- Conventional defoamer addition pipeline, 3- Emergency defoamer addition pipeline, 4- Bioreactor, 5- Defoamer storage tank, 6- Defoamer addition pump, 7- Defoamer flow meter, 8- Defoamer regulating valve, 9- First automatic control switch valve, 10- First check valve, 11- Conventional defoamer storage tank, 12- Conventional defoamer addition pump, 13- Conventional defoamer flow meter, 14- Conventional defoamer regulating valve, 15- Second automatic control switch valve. 16-Second check valve, 17-Rapid defoamer storage tank, 18-Rapid defoamer addition pump, 19-Dosing tank, 20-Rapid defoamer switch valve, 21-Third check valve, 22-First gas content detector, 23-Second gas content detector, 24-Spray pipe, 25-Gas-liquid separator, 26-Gas-liquid separator level gauge, 27-Production water inlet pipe, 28-Production water flow meter, 29-Production water regulating valve, 30-Third automatic control switch valve. Detailed Implementation

[0019] Example 1 This embodiment provides a device for controlling the gas content in gas fermentation, including a reactor system, a production water inlet system, a background defoamer addition system, a conventional defoamer addition system, an emergency defoamer addition system, and a control center.

[0020] Please refer to Figure 1 The reactor system includes a bioreactor 4, a spray pipe 24, a first gas content detector 22, and a second gas content detector 23. The spray pipe 24 is installed at the top of the bioreactor 4, adding material into the bioreactor 4 via top spraying. The first gas content detector 22 and the second gas content detector 23 are located within the bioreactor 4, respectively detecting the gas content at corresponding points in the culture medium. The height of the first gas content detector 22 is limited to be less than that of the second gas content detector 23. In some embodiments, the first gas content detector 22 is located in the lower-middle or middle part of the bioreactor 4, and the second gas content detector 23 is located in the upper part of the bioreactor 4. Here, "lower-middle," "middle," and "upper" refer to their relative positions within the liquid inside the bioreactor 4, and the specific height range can be adjusted.

[0021] Please refer to Figure 1 The production water inlet system includes a production water inlet pipe 27, a production water flow meter 28, and a production water regulating valve 29. The production water inlet pipe 27 is connected to the lower part of the bioreactor 4, and the production water supplied to the bioreactor 4 is injected into the lower part of the bioreactor 4. Both the production water flow meter 28 and the production water regulating valve 29 are installed on the production water inlet pipe 27. The production water flow rate entering the bioreactor 4 is obtained through the production water flow meter 28, and the production water flow rate is regulated through the production water regulating valve 29.

[0022] In some embodiments, the production water inlet pipe 27 is also equipped with a third automatic control switch valve 30, which acts as the main water inlet switch and needs to be installed upstream of the production water flow meter 28 and the production water regulating valve 29.

[0023] Please refer to Figure 1 The background defoamer addition system includes a defoamer addition pipeline 1, a defoamer storage tank 5, a defoamer addition pump 6, a defoamer flow meter 7, and a defoamer regulating valve 8. The defoamer storage tank 5, the defoamer addition pump 6, the defoamer flow meter 7, and the defoamer regulating valve 8 are all installed on the defoamer addition pipeline 1. They can be installed in the above order, or in other orders, such as by swapping the positions of the defoamer flow meter 7 and the defoamer regulating valve 8. One end of the defoamer addition pipeline 1 is connected to the bioreactor 4 to facilitate the addition of defoamer to the bioreactor 4. This connection forms a connection point, such as... Figure 1 As shown, the connection point is limited to below the first gas content detector 22.

[0024] In this embodiment, the actual amount of defoamer added is obtained through the defoamer flow meter 7, the required defoamer flow data is calculated based on the data from the production water flow meter 28, and the background defoamer addition system is regulated by the control center to ensure that the defoamer is added correctly and automatically; in this process, the data provided by the defoamer flow meter 7 is beneficial for feedback control.

[0025] In some implementation methods, please refer to Figure 1 The defoamer addition pipeline 1 is also equipped with a first self-controlled switch valve 9 and a first check valve 10, which prevents liquid backflow.

[0026] Please refer to Figure 1 The conventional defoamer addition system includes a conventional defoamer addition pipeline 2, a conventional defoamer storage tank 11, a conventional defoamer addition pump 12, a conventional defoamer flow meter 13, and a conventional defoamer regulating valve 14. The conventional defoamer storage tank 11, conventional defoamer addition pump 12, conventional defoamer flow meter 13, and conventional defoamer regulating valve 14 are all installed on the conventional defoamer addition pipeline 2. They can be installed in the above order, or in other orders, such as by swapping the positions of the conventional defoamer flow meter 13 and the conventional defoamer regulating valve 14. The conventional defoamer addition pipeline 2 is connected to a spray pipe 24, and the added conventional defoamer enters the bioreactor 4 through the spray pipe 24. In this embodiment, the addition of the conventional defoamer is related to the detection parameters of the first gas content detector 22.

[0027] In some implementation methods, please refer to Figure 1 The conventional defoamer addition pipeline 2 is also equipped with a second self-controlled switch valve 15 and a second check valve 16, which prevents backflow.

[0028] Please refer to Figure 1 The emergency defoamer addition system includes an emergency defoamer addition pipeline 3, a rapid defoamer storage tank 17, a rapid defoamer addition pump 18, a dosing tank 19, and a rapid defoamer on / off valve 20. The rapid defoamer storage tank 17, rapid defoamer addition pump 18, dosing tank 19, and rapid defoamer on / off valve 20 are sequentially installed on the emergency defoamer addition pipeline 3. The emergency defoamer addition pipeline 3 is connected to a spray pipe 24, through which the emergency defoamer enters the bioreactor 4. In this embodiment, the addition of the rapid defoamer is related to the detection parameters of the second gas content detector 23.

[0029] In some implementations, the emergency defoamer addition line 3 is also equipped with a third check valve 21 to prevent liquid backflow.

[0030] Here, it is necessary to clearly distinguish between fast-acting defoamers and conventional defoamers. In this embodiment, the defoamer storage tank 5 stores defoamers with good defoaming effect and long defoaming time, the conventional defoamer storage tank 11 stores conventional defoamers with moderate defoaming effect, and the fast-acting defoamer storage tank 17 stores fast-acting defoamers with rapid defoaming effect. The terms "moderate defoaming effect" and "rapid defoaming effect" are relative. Generally, conventional defoamers have a relatively long defoaming time, while fast-acting defoamers have a relatively short defoaming time. Conventional defoamers can be domestically produced, while fast-acting defoamers can be imported 3110 or 31R types.

[0031] In the gas content control device for gas fermentation in this embodiment, the control center is connected to the first gas content detector 22, the second gas content detector 23, the production water flow meter 28, the production water regulating valve 29, the defoamer flow meter 7, the defoamer regulating valve 8, the conventional defoamer flow meter 13, the conventional defoamer regulating valve 14, the rapid defoamer addition pump 18, and the rapid defoamer switch valve 20. The defoamer regulating valve 8 is controlled by the data from the production water flow meter 28. The conventional defoamer feed is controlled when the data from the first gas content detector 22 is abnormal, and the rapid defoamer feed is controlled when the data from the second gas content detector 23 is abnormal.

[0032] The following provides a specific application scenario of the gas content control device in gas fermentation according to this embodiment, in order to fully illustrate the control device. The first, second, and third descriptions below are only for distinguishing purposes and do not reflect their importance: First, regarding the background addition method of the defoamer. At the initial stage of continuous gas fermentation operation in bioreactor 4, gas and production water are continuously introduced into bioreactor 4. In order to control the stable operation of bioreactor 4, the required defoamer flow rate is calculated based on the data from the production water flow meter 28. The defoamer regulating valve 8 is adjusted according to the calculated data to finally make the actual defoamer flow rate the required value.

[0033] Second, regarding the conventional defoamer addition method. At the initial stage of continuous operation of gas fermentation, the raw material gas is continuously introduced into bioreactor 4, and the first gas content detector 22 begins to display data. The data will increase as the gas volume increases. In order to ensure the stable operation of bioreactor 4, the value of the first gas content detector 22 needs to be controlled within the limit range. If it is higher or lower than the control range, adjustment is required. When the bioreactor 4 is operating stably, the value of the first gas content detector 22 is controlled within the limit range by injecting conventional defoamer. When the value of the first gas content detector 22 exceeds the limit range, the amount of conventional defoamer injected needs to be increased, for example by opening the conventional defoamer regulating valve 14 and / or increasing the frequency of the conventional defoamer adding pump 12, which is a frequency converter pump, until the reading of the first gas content detector 22 drops to the limit range and remains stable. When the value of the first gas content detector 22 is less than the limit range, the amount of conventional defoamer injected needs to be reduced so that the reading of the first gas content detector 22 rises to the limit range and remains stable.

[0034] Third, regarding the emergency defoamer addition method. During continuous operation of gas fermentation, when the reading of the second gas content detector 23 reaches or exceeds the limit, the control center receives this signal and opens the rapid defoamer switch valve 20 to quickly inject the rapid defoamer in the dosing tank 19 into the bioreactor 4, achieving the purpose of rapid foam control. After the defoamer injection is completed, the control center will start the rapid defoamer addition pump 18 to refill the dosing tank 19 with rapid defoamer. If the reading of the second gas content detector 23 falls back to within the limit, injection into the bioreactor 4 will not continue. If the second gas content detector 23 still exceeds the limit, the emergency defoamer addition system will be restarted for another injection until the reading of the second gas content detector 23 falls back below the limit. The purpose of using the dosing tank 19 is to quickly and quantitatively inject rapid defoamer into the bioreactor 4. Generally, one abnormality requires the dosing tank 19 to operate 1 to 3 times.

[0035] In some implementation methods, please refer to Figure 1 The reactor system also includes a gas-liquid separator 25 installed on the top tail gas pipeline of the bioreactor 4. The gas-liquid separator 25 is equipped with a gas-liquid separator level gauge 26, which is connected to the control center. The control center controls the feeding of rapid defoamer when the data from the gas-liquid separator level gauge 26 is abnormal. By using the gas-liquid separator level gauge 26 in conjunction with the emergency defoamer addition method, the stability and controllability of the gas content within the bioreactor 4 are further improved.

[0036] When using the gas-liquid separator 25 and its level gauge 26, regarding the emergency defoamer addition method, when a liquid level appears in the gas-liquid separator 25, it indicates that foaming and liquid escape have occurred in the bioreactor 4. When liquid accumulates in the gas-liquid separator 25 and the level gauge 26 reaches its limit, the control center receives this signal and opens the rapid defoamer switch valve 20 to quickly inject the rapid defoamer from the dosing tank 19 into the bioreactor 4, achieving rapid foam control. After the rapid defoamer is injected, if the level gauge 26 still exceeds the limit, the emergency defoamer addition system is restarted for further injection until the level gauge 26 returns to below the limit. The above demonstrates two scenarios where the emergency defoamer addition system is regulated by the level gauge 26 and the second gas content detector 23, respectively. The emergency defoamer addition system can be activated when either of these scenarios exceeds its limit.

[0037] In some implementations, the defoamer addition pipeline 1 is φ15, and the defoamer addition pump 6 is a variable frequency pump with a flow rate of 1-7 L / h. The defoamer addition amount is counted as 3-5 ppm of the production water addition amount. In the early stage of fermentation, when the fermentation gas volume is low, the defoamer addition amount can be 3 ppm. As the fermentation gas volume increases, the defoamer addition amount increases to 5 ppm.

[0038] In some embodiments, the conventional defoamer addition pipeline 2 is φ15, and the conventional defoamer addition pump 12 is a variable frequency pump with a flow rate of 1-7 L / h. In some embodiments, the gas holdup of the bioreactor 4 in the detection area of ​​the first gas holdup detector 22 is controlled within the range of 0.15-0.25. If the value displayed by the first gas holdup detector 22 is within this range, the amount of conventional defoamer added is generally 2-3 L / h. If it is lower or higher than the limit, the addition amount is adjusted by changing the operating frequency of the conventional defoamer addition pump 12 and / or adjusting the conventional defoamer regulating valve 14, thereby ultimately controlling the gas holdup at that location to be stable.

[0039] In some embodiments, the rapid defoamer addition pipeline adopts a φ20 size, the rapid defoamer addition pump 18 is a centrifugal pump, which is a fixed frequency pump, and the pump flow rate can be selected as 100L / h; the volume of the dosing tank 19 is 2L; the gas content limit of the upper part of the bioreactor 4 is below 0.30; the liquid level limit of the gas-liquid separator 25 is any value in the range of 0-0.1m, for example, the control limit is 0.1m.

[0040] In some embodiments, the connection between the defoamer addition line 1 and the bioreactor 4 is higher than the vent of the bioreactor 4, so that the injected defoamer can easily diffuse within the bioreactor 4.

[0041] In summary, the gas content control device in this embodiment regulates the gas content of the fermentation mash by combining a background defoamer addition system, a conventional defoamer addition system, and an emergency defoamer addition system. By continuously adjusting the injection volume of defoamer and antifoamer through relevant data and the control center, a stable environment is established in the bioreactor 4 to ensure that the gas content of the fermentation mash is within the target range. The gas-liquid contact is good, ensuring high gas utilization and stable operation of the fermentation system.

[0042] On the other hand, the gas content control device used in this embodiment reduces errors caused by human operation, which can not only stably regulate the gas content of the fermentation mash, but also save labor.

[0043] Example 2 Based on the gas content control device in gas fermentation provided in Example 1, this example provides a more detailed feasible implementation for the connection position between the relevant mechanism and the bioreactor 4.

[0044] In some implementations, the connection between the defoamer addition pipeline 1 and the bioreactor 4 is slightly higher than the air inlet of the bioreactor 4, with the height difference controlled within the range of 0.2m-4m.

[0045] In some implementation schemes, the first gas content detector 22 is positioned slightly above the connection point between the defoamer addition pipeline 1 and the bioreactor 4, with the height difference controlled within the range of 0.2m-4m. In some implementations, the second gas content detector 23 is slightly lower than the liquid level in the bioreactor 4, i.e. the highest liquid level, and the height difference is controlled within the range of 0.5-4m.

[0046] The following is a specific implementation scheme, based on a bioreactor 4 with a height of 30m, the actual liquid height inside the bioreactor 4 is about 29m, the height of its vent is 6m, the connection point of the antifoaming agent addition pipeline 1 to the bioreactor 4 is at a height of 7m to 8m in the liquid inside the bioreactor 4; the height of the first gas content detector 22 in the liquid inside the bioreactor 4 is in the range of 8m to 10m, and the endpoint is not selected at the same height as the connection point of the antifoaming agent addition pipeline 1 to the bioreactor 4; the height of the second gas content detector 23 in the liquid inside the bioreactor 4 is in the range of 26m to 28m.

[0047] Example 3 Based on the gas content control device for gas fermentation provided in Example 1, this example provides a method for controlling the gas content during gas fermentation, including: Under the condition of continuous operation of bioreactor 4, the production water inlet system supplies water to bioreactor 4, and the control center controls the addition flow rate of defoamer addition pipeline 1 based on the detection data of production water flow meter 28. Under the condition of continuous operation of bioreactor 4, the control center includes controlling the addition flow rate of conventional defoamer addition pipeline 2 based on the detection data of the first gas content detector 22; Under the condition of continuous operation of bioreactor 4, the control center controls the addition of emergency defoamer in pipeline 3 based on the detection data of the second gas content detector 23.

[0048] Example 4 Based on the gas content control device or method in gas fermentation described in the above embodiments, this embodiment provides a related experiment. Taking the technical solution of using a background defoamer addition system, a conventional defoamer addition system, and an emergency defoamer addition system, and including the application of a gas-liquid separator level gauge 26, as Experimental Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are provided as follows.

[0049] Compared with Example 1, the difference in Comparative Example 1 is that the background defoaming agent addition system is not activated during the continuous operation of gas fermentation.

[0050] Compared with Example 1, the difference in Comparative Example 2 is that the conventional defoamer addition system is not activated during the continuous operation of gas fermentation.

[0051] Compared with Example 1, the difference in Comparative Example 3 is that the emergency defoamer addition system is not activated during the continuous operation of gas fermentation.

[0052] The above production operation was carried out, and the process was recorded as shown in the table below:

[0053] As can be seen from the data in the table above, In Comparative Example 1, when the background defoamer addition system was not activated during gas fermentation production, the amount of conventional defoamer and the frequency of rapid defoamer addition both increased. The gas holdup in the lower part of bioreactor 4 was generally between 0.20 and 0.28, the gas holdup in the upper part of bioreactor 4 was below 0.3, and there was no liquid level display in gas-liquid separator 25. This indicates that without the addition of background defoamer, the gas holdup in the bioreactor fluctuates more significantly, making stable control more difficult.

[0054] In Comparative Example 2, when the conventional defoamer addition system was not activated during gas fermentation production, the amount of defoamer added and the frequency of rapid defoamer addition both increased. The gas holdup in the lower part of bioreactor 4 was generally between 0.22 and 0.32, while the gas holdup in the upper part of bioreactor 4 was below 0.3, and there was no liquid level display in gas-liquid separator 25. This indicates that without the addition of conventional defoamer, the gas holdup in the bioreactor fluctuates significantly, making stable control difficult.

[0055] In Comparative Example 3, when the emergency defoamer addition system was not activated during gas fermentation production, both the amount of defoamer and conventional defoamer added increased. The gas holdup in the lower part of bioreactor 4 was generally between 0.20 and 0.28, while the gas holdup in the upper part of bioreactor 4 repeatedly exceeded 0.3, and the liquid level in the gas-liquid separator (level 25) repeatedly exceeded 0.1. This indicates that without the addition of a rapid defoamer, the gas holdup in the bioreactor fluctuates more significantly, making stable control more difficult.

[0056] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0057] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A gas content control device in a gas fermentation, characterized by, The control device includes: The reactor system includes a bioreactor, a spray pipe installed at the top of the bioreactor, and a first gas holdup detector and a second gas holdup detector installed inside the bioreactor, wherein the first gas holdup detector is lower than the second gas holdup detector. The production water inlet system includes a production water inlet pipeline and a production water flow meter installed on the production water inlet pipeline, wherein the production water inlet pipeline is connected to the lower part of the bioreactor; Background: Defoamer addition system, including defoamer addition pipeline and defoamer storage tank installed on the defoamer addition pipeline, one end of the defoamer addition pipeline is connected to the bioreactor and the connection point is lower than the first gas content detector; A conventional defoamer addition system includes a conventional defoamer addition pipeline and a conventional defoamer storage tank installed on the conventional defoamer addition pipeline, wherein the conventional defoamer addition pipeline is connected to the spray pipe; An emergency defoamer adding system includes an emergency defoamer adding pipeline and a rapid defoamer storage tank installed on the emergency defoamer adding pipeline, wherein the emergency defoamer adding pipeline is connected to the spray pipe; The control center is connected to the first gas holdup detector, the second gas holdup detector, and the production water flow meter. It controls the flow rate of defoamer added to the defoamer storage tank based on the data from the production water flow meter. When the data from the first gas holdup detector is abnormal, it controls the addition of conventional defoamer to the conventional defoamer storage tank. When the data from the second gas holdup detector is abnormal, it controls the addition of rapid defoamer to the rapid defoamer storage tank, so as to restore the gas holdup in the bioreactor to within the limit range.

2. The control device of claim 1, wherein The production water inlet system also includes a production water regulating valve installed on the production water inlet pipeline; The background defoamer addition system also includes a defoamer addition pump, a defoamer flow meter, and a defoamer regulating valve installed on the defoamer addition pipeline; The conventional defoamer addition system also includes a conventional defoamer addition pump, a conventional defoamer flow meter, and a conventional defoamer regulating valve installed on the conventional defoamer addition pipeline; The emergency defoamer addition system also includes a rapid defoamer addition pump, a dosing tank, and a rapid defoamer switch valve installed on the emergency defoamer addition pipeline; The control center is signal-connected to the first gas content detector, the second gas content detector, the production water flow meter, the production water regulating valve, the defoamer flow meter, the defoamer regulating valve, the conventional defoamer flow meter, the conventional defoamer regulating valve, the rapid defoamer addition pump, and the rapid defoamer switch valve.

3. The control device of claim 2, wherein Both the defoamer adding pump and the conventional defoamer adding pump include variable frequency pumps, while the rapid defoamer adding pump includes a fixed frequency pump.

4. The control device of claim 2, wherein The connection point between the defoamer addition pipeline and the bioreactor is higher than the aeration port of the bioreactor.

5. The control device of claim 4, wherein The connection point between the defoamer addition pipeline and the bioreactor is 0.2-4m higher than the aeration port of the bioreactor; The first gas content detector is 0.2-4m higher than the connection point between the antifoaming agent addition pipeline and the bioreactor; The second gas content detector is 0.5-4m lower than the liquid level in the bioreactor.

6. The control device as described in claim 2, characterized in that, The defoamer addition pipeline is also equipped with a first self-controlled switching valve and a first check valve; The conventional defoamer addition pipeline is also equipped with a second self-controlled switch valve and a second check valve. The emergency defoamer addition pipeline is also equipped with a third check valve; The production water inlet pipeline is also equipped with a third self-controlled switch valve.

7. The control device as described in claim 2, characterized in that, The control limit for the first gas content detector is 0.15-0.25; the control limit for the second gas content detector is 0-0.

3.

8. The control device as described in any one of claims 1-7, characterized in that, The reactor system also includes a gas-liquid separator installed on the top tail gas pipeline of the bioreactor. The gas-liquid separator is equipped with a gas-liquid separator level gauge, which is signal-connected to the control center. The control center controls the feeding of the rapid defoamer when the gas-liquid separator level gauge data is abnormal.

9. The control device as described in claim 8, characterized in that, The control limit value of the liquid level gauge of the gas-liquid separator is any value in the range of 0-0.1m.

10. A method for controlling gas content in gaseous fermentation, characterized in that, The control method, employing the control device as described in any one of claims 1-9, comprises: Under the condition of continuous operation of the bioreactor, the production water inlet system supplies water to the bioreactor, and the control center includes controlling the addition flow rate of the defoamer addition pipeline based on the detection data of the production water flow meter. Under the condition of continuous operation of the bioreactor, the control center includes controlling the addition flow rate of the conventional defoamer addition pipeline based on the detection data of the first gas content detector; Under conditions of continuous operation of the bioreactor, the control center includes controlling the addition of the emergency defoamer via the pipeline based on the detection data from the second gas content detector.

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