CN105733938B - A kind of the bioelectricity synthesizer and bioelectricity synthetic method of continuously-running - Google Patents

Abstract

The invention discloses a bioelectric synthesis device and a bioelectric synthesis method capable of continuous operation. The device includes: a three-chamber reactor, and the three-chamber reactor is divided into an anode chamber, a third chamber and a cathode chamber arranged in sequence by an ion membrane The anode chamber is provided with a conductive anode, and the cathode chamber is provided with a conductive cathode, and the conductive anode and the conductive cathode are connected to an external power supply through a wire; the gas supply device is communicated with the cathode chamber; an extraction reactor, which has a feed port, An organic phase outlet and an inorganic phase outlet, wherein the feed port is connected to the third chamber through a feed pipe, the organic phase outlet is connected to a distillation separation device, and the inorganic phase outlet is connected to the third chamber through a return pipe. The invention mainly solves the problem of cyclically extracting and concentrating the synthesized small molecule organic acid so that the bioelectric synthesis reactor can operate continuously.

Description

A bioelectric synthesis device capable of continuous operation and a bioelectric synthesis method

technical field

The invention belongs to the technical field of bioelectric synthesis, and in particular relates to a continuously operating bioelectric synthesis device and a bioelectric synthesis method.

Background technique

Microbial electrosynthesis (MES, microbial electrosynthesis) technology uses electrosynthetic microorganisms to obtain electrons at the cathode of the bioelectrochemical system, reduce carbon dioxide in the microbial cells, and generate small molecular acids, alcohols and other organic substances, and through biological catalytic synthesis, no Secondary pollution, with high efficiency, mild reaction, and green environmental protection.

At present, the conversion of CO ₂ to organic substances such as acetic acid (mBio, 2010, 2, 103-113; EST, 2013, 47, 6023-6029), butyric acid (mBio, 2014, 5, 1636-1650) has been realized by using the bioelectric synthesis system . The application number is 201280040307.3, which has applied for a patent for electrosynthesis and reduction of carbon dioxide to generate organic matter, allowing carbon dioxide to enter an electronegative container for reaction to obtain organic matter. In one embodiment, different discharge methods are used to generate organic matter from the electronegative gas. Generate non-equilibrium electronegativity ions, and reduce carbon dioxide to generate organic compounds. When carbon dioxide enters a container containing at least one electronegative gas, such as water, ammonia, bromine, and iodine, it reacts to form organic compounds, such as ethanol, methanol, and oxalic acid in the case of water, and in the presence of ammonia In the case of iodine gas, urea is formed, and in the case of iodine gas, tetraiodomethane is formed.

At present, there is no specific operation method for how to extract, concentrate, and utilize the synthesized small molecule organic acids, and the synthesized organic acids cannot be directly used. The traditional extraction method is generally intermittent, such as the application number 201410270337.4 The Chinese invention application document discloses a method for purifying an organic acid, comprising: (a) adding an inorganic flocculant to a fermentation broth containing an organic acid to form a mixture; (b) subjecting the mixture to a centrifugation procedure to obtain a supernatant and Precipitate, wherein the organic acid is located in the supernatant; (c) subjecting the supernatant to a thin film extraction procedure to obtain an extract, wherein the thin film extraction procedure comprises: (i) carrying out the supernatant with an oil phase extracting the oil phase to form an oil phase extraction product; and (ii) back extracting the oil phase extraction product with a back extraction phase to form the extract, wherein during the back extraction, adjusting the pH of the back extraction phase to making at least one carboxyl moiety of the organic acid in the formed extract into a carboxyl salt state; and (d) subjecting the extract to a crystallization procedure to obtain crystals of the organic acid. In the application of this invention, the organic acid is purified in batch mode, which cannot be operated continuously, and the batch mode has the disadvantages of slow extraction and low efficiency.

Contents of the invention

The invention provides a bioelectric synthesis device and a bioelectric synthesis method capable of continuous operation, mainly solving the problem of cyclically extracting and concentrating the synthesized small molecule organic acid so that the bioelectric synthesis reactor can operate continuously.

A bioelectric synthesis device capable of continuous operation, comprising:

A three-chamber reactor, the three-chamber reactor is divided into an anode chamber, a third chamber and a cathode chamber arranged in sequence by an ion membrane, a conductive anode is arranged in the anode chamber, a conductive cathode is arranged in the cathode chamber, and the conductive anode and the conductive cathode are externally connected by wires power supply;

a gas supply device communicated with the cathode chamber;

An extraction reactor, the extraction reactor has a feed inlet, an organic phase outlet and an inorganic phase outlet, wherein the feed inlet is connected to the third chamber by a feed pipe, the organic phase outlet is connected to a distillation separation device, and the inorganic phase outlet is connected by a reflux A tube connects the third chamber.

The ion membrane between the anode chamber and the third chamber is a cationic membrane, and the ion membrane between the third chamber and the cathode chamber is an anion membrane.

The present invention adds a third chamber to initially store the produced small molecule organic acid, use a circulating pump to extract the small molecule organic acid in the third chamber, and then return the inorganic aqueous solution to the third chamber, and the organic phase Transport to a distillation separation unit for distillation so that such a step can be run continuously.

Preferably, an automatic pH monitoring and adjustment system for monitoring the pH in the third chamber is also provided.

Preferably, the extraction reactor is a tower-type circulating extraction reactor, including a tower body and an agitator arranged in the tower body, the feed inlet is located at the top of the tower body, the organic phase outlet is located in the middle of the tower body, and the inorganic phase The outlet is located at the bottom of the tower body.

Further preferably, a circulation pump is arranged on the feed pipe.

Further preferably, a bracket for supporting the tower body is also provided.

Preferably, the gas supply device includes a gas source supply device, a gas pipeline connecting the gas source supply device and the cathode chamber, and a gas pressure controller arranged on the gas pipeline.

The gas source supply device is composed of several different gas storage tanks and metering and mixing devices.

Preferably, the size of the three-chamber reactor: the volume ratio of the third chamber to the cathode chamber and the anode chamber is 3:(1-2):(1-2), most preferably 3:2:2.

The present invention also provides a method for continuous bioelectric synthesis using the bioelectric synthesis device, comprising the following steps:

(1) Electrosynthetic bacteria are inoculated in the cathode chamber, the mixture of carbon dioxide and inert gas is sent into the cathode chamber, and the power supply is turned on to carry out the bioelectric synthesis reaction;

(2) The acid radicals and hydrogen ions generated in the cathode chamber pass through the anion membrane and temporarily store in the third chamber, and the pH in the third chamber is controlled according to the pKa of the small molecule organic acid generated in the cathode chamber to ensure the penetration of acid radical ions After the anion membrane, most of them exist in the form of molecules in the third chamber, and the solution in the third chamber is transported to the extraction reactor through the circulation pump for extraction;

(3) The solution sent into the extraction reactor gradually sinks after mixing and stirring, the inorganic phase solution is refluxed in the third chamber, and the organic phase solution is separated into the distillation separation device for distillation; Circulation extraction is carried out in the reactor;

Steps (1) to (3) are carried out in a cycle, and the bioelectric synthesis reaction is continuously carried out.

In order to allow the microorganisms to perform electrosynthesis well, preferably, the mixed gas is nitrogen and carbon dioxide with a volume ratio of 1:0.25-0.43, and the pressure of the cathode chamber is controlled by a pressure controller to be 0.2-0.3 MPa.

Further preferably, a mixed gas nitrogen and carbon dioxide is introduced into the cathode chamber with a volume ratio of 1:0.25, and the pressure of the cathode chamber is controlled to be 0.2 MPa.

In order to allow the acid radical ion to pass through the anion membrane, most of it exists in the form of molecules in the third chamber; preferably, the pH of the third chamber is controlled at 3.3-3.8.

More preferably, the pH of the third chamber is controlled to be 3.5, so that acid radical anions can quickly pass through the anion membrane; and most of them exist as molecules in the third chamber.

In order to better mix the extractant and the extraction product, preferably, the hydraulic gradient in the mixing zone is 10 ⁴ -10 ⁵ during the mixing and stirring.

Further preferably, the hydraulic gradient in the mixing zone of the extraction cycle reactor is controlled at 2×10 ⁴ , so that the extractant and the extractant are quickly mixed and dissolved.

The microorganisms in the cathode chamber are acid-producing autotrophic electrosynthetic bacteria, and further preferably, the acid-producing electrosynthetic bacteria inoculated in the cathode chamber are Sporomusa ovata (DSM311), Sporomusa sphaeroides (DSM 2875), Clostridium ljungdahlii (DSM13528 ), Clostridium aceticum (DSM 1496) or a combination of several.

Selecting an extractant with a large difference in boiling point from the small molecule organic acid and being insoluble in water to extract the small molecule organic acid, preferably, the extractant is an organic solvent that is insoluble in water and has a large difference in boiling point from the small molecule organic acid, Such as one of ethyl acetate, propyl acetate, tetrachloromethane.

The extracted products are all small molecular organic acids synthesized in the cathode chamber.

The present invention transforms a two-chamber bioelectric synthesis reactor into a three-chamber reactor, inoculates electrosynthetic microorganisms in the cathode chamber, feeds nitrogen and carbon dioxide mixed gas to carry out bioelectric synthesis, and regulates the pressure of the cathode chamber by an air pressure controller. 0.2 ~ 0.3MPa, and then can control the flow of gas. The anode chamber is separated from the third chamber by a cation membrane, and the cathode chamber is separated from the third chamber by an anion membrane. Among them, sodium ions and hydrogen ions are generated in the anode chamber and pass through the cationic membrane to the third chamber. Bicarbonate and various organic acid radicals are generated in the cathode chamber and pass through the anion membrane to the third chamber. This process must control the pH value of the third chamber. At about 3.5, otherwise it will affect the acid radical ions to pass through the anion membrane. At this time, the small molecule organic acid is initially stored in the third chamber. The liquid in the third chamber is pumped into the external extraction tower through the circulation pump, and the extractant is added to extract the small molecule organic acid, first stirred and mixed, and then through the gradual sinking of the extraction tower (that is, the mixed layer), the solution is extracted The bottom of the tower is stratified, the inorganic phase water layer is circulated into the third chamber through the circulation pump, and the organic phase layer is separated to the outside for distillation and separation.

Beneficial effects of the present invention:

(1) The present invention develops a green and sustainable route, which can reduce carbon dioxide, a greenhouse gas.

(2) The present invention solves the problem of continuous extraction and separation of small molecule organic acids in bioelectric synthesis.

(3) In the present invention, the solution in the third chamber is extracted and circulated to promote the rate of bioelectric synthesis in the cathode chamber.

Description of drawings

Figure 1 is a schematic diagram of the structure of a bioelectric synthesis reactor.

Figure 2 is a schematic longitudinal section of the extraction cycle reactor.

The reference signs shown in the figure are as follows:

1-Cathode chamber 2-Anode chamber 3-Third chamber

4-Conductive anode 5-Conductive cathode 6-Cation membrane

7-anion membrane 8-air pressure controller 9-air source supply device

10-extraction reactor 11-pH automatic monitoring and adjustment system 12-DC power supply

13-circulation pump 14-stirred layer 15-mixed layer

16-organic phase layer 17-inorganic phase layer 18-distillation separation device

19-Reactor 20-Tower 21-Stent

Detailed ways

As shown in Figures 1 and 2, a bioelectric synthesis reactor that can operate continuously includes a reactor, a gas supply system, a pH control system, an extraction reactor and a distillation separation device.

The reactor 19 is a three-chamber reactor, and the reactor is followed by an anode chamber 2, a third chamber 3 and a cathode chamber 1. The anode chamber and the third chamber are separated by a cationic membrane 6, and the third chamber and the cathode chamber are separated by an anion chamber. Membranes 7 are separated, a conductive anode 4 is arranged in the anode chamber, and a conductive cathode 5 is arranged in the cathode chamber, and the conductive anode and the conductive cathode are externally connected to a DC power supply 12 through wires.

The cathode chamber is connected to a gas supply system. The gas supply system includes a gas source supply device 9 and a gas pipeline connecting the gas source supply device and the cathode chamber. An air pressure controller 8 is arranged on the gas pipeline, and the air pressure controller controls the air pressure in the cathode chamber. The gas source supply device 9 includes each raw material gas sub-bottling and metering and mixing equipment.

The third external extraction reactor 10, the extraction reactor is a tower-type circulating extraction reactor, including a tower body 20 and a support 21 made of the tower body, an agitator is arranged in the tower body, and the blade of the agitator is located in the upper half of the tower body When carrying out extraction and separation, the layer area where the stirring blades are located in the tower is the stirring layer 14, and below the stirring layer 14 are the mixed layer 15, the organic phase layer 16 and the inorganic phase layer 17, and the feed port of the tower body is located in the stirring layer. The feed port is connected to the third chamber through the feed pipe, and a circulation pump 13 is arranged on the feed pipe. The organic phase outlet of the tower body is located in the organic phase layer, and the organic phase outlet is connected to the distillation separation device 18. The inorganic phase outlet of the tower body is located in the tower body. The bottom of the body is connected to the third chamber through the return line. The third chamber is also equipped with an automatic pH monitoring and adjustment system 11, and the automatic pH monitoring and adjustment system 11 itself can be realized by existing technologies.

Among them, the cathode chamber is the part of bioelectric synthesis. The mixed gas of carbon dioxide and nitrogen enters the cathode chamber through the air pressure controller 8, and synthesizes small molecule organic acid radicals on the surface of the cathode through the synergistic catalysis of microorganisms and electricity. Oxygen and hydrogen ions are generated in the anode chamber, and the hydrogen ions enter the third chamber through the cationic membrane, and combine with organic acid radicals to form small molecular organic acid molecules, which are temporarily stored in the third chamber.

Through the reflux of the circulation pump, the organic acid is transported to the external tower-type extraction circulation reactor for extraction (as shown in Figure 2), and the extraction agent is added to the external extraction tower, mixed and stirred, and the longitudinal separation of the extraction tower is carried out. It is a stirring layer, a mixing layer, an organic phase layer and an inorganic water layer. The separated inorganic aqueous solution is circulated into the third chamber, while the organic phase enters the distillation separation device for distillation separation; on the one hand, this process separates and purifies small molecule organic acids, realizing The continuous operation of the bioelectric synthesis device is improved; on the other hand, the concentration of small molecule acid ions in the cathode chamber is reduced, thereby accelerating the bioelectric synthesis reaction in the cathode chamber.

The process steps of bioelectric synthesis by the device of the present invention are as follows:

(1) Electrosynthetic bacteria are inoculated in the cathode chamber, and the bioelectric synthesis reaction is carried out under the condition of energizing nitrogen and carbon dioxide mixed gas.

(2) The generated acid radicals and hydrogen ions are temporarily stored in the third chamber, and the pH of the third chamber is controlled according to the pKa of the small molecule organic acid produced in the cathode chamber, so as to ensure that the acid radical ions pass through the anion membrane, and in the third chamber Most of the chamber exists in molecular form (if the pH of acetic acid is controlled below 2.80, and the pH of propionic acid is controlled below 2.78, it basically exists in molecular form), and the solution in the third chamber is transported to the outdoor extraction tower for extraction through a circulating pump.

(3) Through the mixing and stirring of the extraction cycle reactor and the gradual sinking, the inorganic aqueous solution is refluxed in the third chamber, and the organic phase solution is separated into the distillation separation device outside the reactor for distillation; then the extraction agent separated by distillation is refluxed to the extraction Circulation extraction is carried out in the tower.

The steps of circulation (1)-(3) can realize the continuous operation of the reactor.

Example 1

In the example, a three-chamber reactor of tempered glass is used, the cathode uses a titanium mesh electrode, and the anode uses an ordinary graphite electrode. Electrosynthetic acid-producing bacteria (Sporomusaovata) are inoculated in the cathode chamber, and the volume ratio of nitrogen and carbon dioxide gas mixture is 1:0.25. And control the cathode chamber pressure to 0.3MPa. Control the pH of the third chamber to be 3.5. The circulation flow rate of the pump is 50mL/min, the hydraulic gradient of the stirrer is controlled at 2×10 ⁴ , and continuous circulation extraction is carried out. After 20 days of operation under the above conditions, the concentration of small molecule organic acids in the third chamber reached 11.3g/L. After extraction, on the one hand, the reactor can be operated continuously, and on the other hand, the concentration of all organic acids in the third chamber can still maintain a concentration of about 11g/L. Wherein the composition of small molecule organic acid before extraction is as shown in table 1:

Table 1

Example 2

In the example, a tempered glass three-chamber reactor is adopted, the cathode adopts a titanium mesh electrode, and the anode adopts an ordinary graphite electrode. Electrosynthetic acid-producing bacteria (Sporomusaovata) are inoculated in the cathode chamber, and the volume ratio of nitrogen gas and carbon dioxide gas mixture is 1:0.43, and Control the cathode chamber pressure to 0.2MPa. The pH of the third chamber was controlled to be 3.8. The circulating flow rate of the pump is 40mL/min, the hydraulic gradient of the agitator is controlled at 1×10 ⁴ , and the concentration of the small molecule organic acid in the third chamber reaches 8.1g/L after 20 days of operation according to the above conditions. After extraction, on the one hand, The reactor can be operated continuously. On the other hand, the concentration of all organic acids in the third chamber can still maintain a concentration of about 8g/L. Wherein the composition of small molecule organic acid before extraction is as table 2:

Table 2

Example 3

In the example, a three-chamber reactor of tempered glass is used, the cathode uses a titanium mesh electrode, and the anode uses an ordinary graphite electrode. Electrosynthetic acid-producing bacteria (Sporomusaovata) are inoculated in the cathode chamber, and the volume ratio of nitrogen and carbon dioxide gas mixture is 1:0.25. And control the cathode chamber pressure to 0.3MPa. Control the pH of the third chamber to be 3.5. But no additional extraction loop reactor is added. After 20 days of operation under the above conditions, the concentration of all small molecule organic acids in the third chamber reached 2.0g/L. Wherein the composition of small molecule organic acid is as table 3:

table 3

The above is only a specific implementation case of the patent of the present invention, but the technical characteristics of the patent of the present invention are not limited thereto. Any changes or modifications made by those skilled in the relevant field within the scope of the present invention are covered by the patent of the present invention. within the scope of the patent.

Claims (5)

1. a kind of method carrying out continuous biological electro synthesis organic acid using bioelectricity synthesizer, which is characterized in that including such as Lower step：

(1) it is inoculated with electro synthesis bacterium in cathode chamber, the gaseous mixture of carbon dioxide and inert gas is sent into cathode chamber, is powered on Carry out bioelectricity synthetic reaction；

(2) acid group and hydrogen ion generated in cathode chamber is kept in through anionic membrane in third room, is produced according in cathode chamber PH is 3.3~3.8 in the pKa controls third room of raw small molecular organic acid, with ensure acid ion through after anionic membrane Third exists in room with molecular forms, and the solution of third room, which is delivered to by circulating pump in extraction reactor, to be extracted；

(3) solution being sent into extraction reactor gradually sinks after mixing, and inorganic phase solution is back in third room, organic phase Solution, which is detached into distillation separator, to be distilled；The extractant of distillation separation is back in extraction reactor again and is followed Ring extracts；

Step (1)~(3) cycle carries out, and is carried out continuously bioelectricity synthetic reaction；

Bioelectricity synthesizer includes：

Three Room reactors, the three Room reactor is interior to be divided into the anode chamber to arrange successively, third room and cathode chamber by ionic membrane, sun Conductive anode is set in pole room, conductive cathode is set in cathode chamber, the conductive anode and conductive cathode pass through the external electricity of conducting wire Source；

Gas supply device is connected with the cathode chamber, and the gas supply device includes air source feeding mechanism, connection air source The gas piping of feeding mechanism and cathode chamber and the gas pressure regulator being arranged on gas piping；

Extraction reactor, the extraction reactor have feed inlet, organic phase outlet and inorganic phase outlet, wherein feed inlet by into Expects pipe connects the third room, separator is distilled in organic phase outlet connection, inorganic phase outlet connects the third by return duct Room；

The extraction reactor is tower cycling extraction reactor, including tower body and the blender that is set in tower body, it is described into Material mouth is located at the top of tower body, organic phase outlet is located at the middle part of tower body, inorganic phase outlet is positioned at the bottom of tower body.

2. method according to claim 1, which is characterized in that the volume ratio of inert gas and carbon dioxide in the gaseous mixture It is 1:(0.25~0.43), control cathode intraventricular pressure are 0.2~0.3MPa by force.

3. stating method according to claim 1, which is characterized in that the hydraulic gradient of mixed zone when being mixed in the extraction reactor Degree is 10⁴~10⁵。

4. stating method according to claim 1, which is characterized in that circulating pump is arranged on the feed pipe.

5. stating method according to claim 1, which is characterized in that the volume ratio of the third room, cathode chamber and anode chamber is 3:(1 ~2):(1~2).