CN104031834B - A kind of photosynthetic bacterium successive reaction hydrogen production process - Google Patents

Abstract

A kind of photosynthetic bacterium successive reaction hydrogen production process adopts continuously producing hydrogen with photosynthetic bacteria reaction unit to carry out yeast culture and reaction product hydrogen; Described device is made up of reactor, raffinate treating pond, Hydrogen collection device, high density product hydrogen nutrient solution case and Photosynthetic bacteria culturing device; It is that photosynthetic bacterium breeds to OD in cultivation that hydrogen is produced in described yeast culture and reaction _{660? nm}after reaching 1.6 ~ 1.9, by volume the millipore filtration III of the bacterium liquid of 4/5 ~ 5/6 by aperture≤0.22 μm is concentrated, bacterium liquid after concentrated carries out photosynthetic hydrogen production at computer regulated lower injecting reactor, and unconcentrated bacterium liquid, after adding new nutrient solution, proceeds multiplication culture.Present method achieves the recycle of substrate, and makes miscellaneous bacteria to enter reactor body by membrane filtration, avoids the impact of miscellaneous bacteria on hydrogen production with photosynthetic bacteria, improves hydrogen generation efficiency and substrate utilization ratio.

Description

A kind of continuous reaction hydrogen production method of photosynthetic bacteria

technical field

The invention relates to a method for continuous reaction hydrogen production by photosynthetic bacteria, in particular to a method for cultivating bacteria and producing hydrogen by reaction using a photosynthetic bacteria continuous hydrogen production reaction device.

Background technique

With the continuous consumption of fossil energy and the increasingly serious environmental pollution caused by its long-term use, human beings will face a very serious energy crisis and environmental degradation. Hydrogen has a high calorific value, fast combustion reaction, and produces water after releasing energy and is renewable, so it is recognized as a clean and green energy. At present, the methods of hydrogen production mainly include electrolysis of water to produce hydrogen, chemical hydrogen production, biological hydrogen production, etc. Compared with other hydrogen production methods, biological hydrogen production has the advantages of low energy consumption, less pollution, and mild reaction conditions. Due to the fast hydrogen production rate of photosynthetic bacteria, high energy utilization rate, and wide spectral range available, there are many related studies.

There are batch, semi-continuous and continuous methods for hydrogen production by photosynthetic bacteria. Due to the problems of small gas production, low gas production rate and low substrate utilization in batch and semi-continuous hydrogen production methods, continuous hydrogen production methods are mainly used at present. In the existing hydrogen production method of photosynthetic bacteria, part of the culture of the bacteria is separated from the hydrogen production phase, and part of the organic combination of the bacterial culture and the hydrogen production of the bacteria. The organic combination of cell culture and cell hydrogen production can ensure the stability of gas production and increase the rate of hydrogen production. However, the growth medium of some photosynthetic bacteria is different from the hydrogen production medium, and the growth medium is not conducive to photosynthetic bacteria. Therefore, combining bacterial culture and bacterial hydrogen production will cause a large amount of growth medium to enter the reactor and The hydrogen production medium is mixed to reduce the hydrogen production efficiency of photosynthetic bacteria. Moreover, there are still many problems in the existing continuous hydrogen production device.

The publication number is CN202415545U, which discloses "a continuous flow microbial fermentation hydrogen production device", which consists of a raw material pool, a peristaltic feed pump, a fermentation reactor, a NaOH reactor, a gas dryer, a gas flow meter, and a gas storage device connected in series. The fermentation reactor is equipped with a stirrer, the waste liquid outlet of the fermentation reactor is connected with the waste liquid collection pool through a peristaltic discharge pump, and a microfiltration membrane is arranged at the bottom of the fermentation reactor. The device realizes the purpose of continuous and efficient hydrogen production. However, when the device is used for continuous hydrogen production, the fermentation waste liquid is directly discharged into the waste liquid collection tank without reflux and repeated fermentation, resulting in the direct loss of a part of the substrate and reducing the utilization rate of the substrate. At the same time, the device lacks a temperature control device, which cannot ensure that the temperature of the fermentation broth is in the temperature range for efficient hydrogen production by microorganisms.

The publication number is CN101538587B, which discloses "a method and device for continuous hydrogen production by photosynthetic bacteria". The method described is a step-by-step method for continuous hydrogen production by photosynthetic bacteria, including two stages of bacterial cell culture and fermentation hydrogen production: after the photosynthetic bacteria and their growth medium are propagated and cultured, when the cultured bacterial cell concentration OD _660nm reaches 1.5~ At 2.0, by volume, 1/10 to 3/10 of the total bacterial liquid is mixed with the growth medium of photosynthetic bacteria by reflux to re-proliferate and cultivate, while the rest of the bacterial liquid is mixed with the hydrogen-producing substrate and then fermented Hydrogen production. The device used is composed of three parts: a bacterial cell incubator, a bacterial material mixing tank and a photosynthetic hydrogen production reactor connected in series. The function of the cell incubator is to provide a continuous and stable supply of cells for the photosynthetic hydrogen production reactor by using a continuous culture device. The role of the bacterial material mixing box is to fully mix the bacteria that have been cultivated to the logarithmic growth phase with the hydrogen-producing substrate, minimize the inhibition of the introduction of air on the bacteria, and complete the adjustment of the pH value of the mixed bacterial solution. Make adjustments to ensure that the pH of the bacterial solution is within the range of 6.8 to 7.2. The function of the photosynthetic hydrogen production reactor is to provide the required light and temperature external conditions for the hydrogen production of photosynthetic bacteria, so that the photosynthetic bacteria can ferment the substrate into hydrogen. In order to increase the hydrogen production, stirring can also be increased here. The bacteria incubator, the bacteria material mixing box and the photosynthetic hydrogen production reactor are respectively connected in series as independent parts. The bacteria incubator, the bacteria material mixing box and the photosynthetic hydrogen production reactor exist as a whole, and the overall internal space is isolated into three spaces which are successively used as the bacteria incubator, the bacteria material mixing box and the photosynthetic hydrogen production reactor. Along the horizontal direction, the overall internal space is separated into three connected or independently closed spaces, wherein at least two staggered partitions can be used to isolate the whole space into three connected spaces. When the method and device of the invention are used to produce hydrogen, 7/10 to 9/10 of the liquid is mixed with the hydrogen-producing substrate to produce hydrogen, resulting in a large amount of growth medium contained in the bacterial liquid mixed with the hydrogen-producing substrate, but the growth The medium is not conducive to the hydrogen production of photosynthetic bacteria, and even inhibits the hydrogen production of some photosynthetic bacteria, which will lead to a decrease in hydrogen production efficiency. The remaining materials in the photosynthetic reactor are directly discharged from the sewage outlet, so that the photosynthetic bacteria in the reactor are also discharged along with the remaining materials, resulting in the loss of photosynthetic bacteria, which makes it difficult to maintain the number of photosynthetic bacteria in the reactor. A part of the substrate is wasted, which reduces the utilization rate of the substrate.

The publication number is CN101845387B, which discloses "a photosynthetic bacteria continuous hydrogen production reactor", which includes a shell, one end of the shell is provided with a feed port and the other end is provided with a discharge port, and the inner wall of the shell is arranged alternately perpendicular to the flow direction of the feed liquid. There is an upper baffle and a lower baffle, a gap is provided between the lower end of the upper baffle and the bottom wall of the housing, and a gap is provided between the upper end of the lower baffle and the top wall of the housing, and it is characterized in that: the upper The lower baffles and the lower baffles are arranged vertically and the shell is alternately divided into a rising zone and a falling zone. The shell corresponding to the rising zone is equipped with a lighting device; the top of the shell is also equipped with a gas collection hole. The reactor is equipped with baffles inside the shell, so that the feed and liquid are completely mixed in the tank. However, after the reactor has been used for a period of time, some photosynthetic bacteria will float on the inner wall of the reactor and affect the light transmission of the reactor. Therefore, the reactor needs to be cleaned regularly to ensure its light transmission. However, the reactor of this invention is a whole and cannot be disassembled, and the baffle plate provided inside increases the difficulty of cleaning the reactor.

In addition, the current photosynthetic biological hydrogen production reaction device cannot prevent the culture solution in the reactor from being polluted by miscellaneous bacteria. Under the influence of miscellaneous bacteria, the hydrogen production efficiency and substrate conversion rate of photosynthetic bacteria will be reduced. Moreover, the existing photosynthetic biological hydrogen production reaction device cannot solve the following two problems that exist when collecting the generated hydrogen. 1. If the generated hydrogen is not compressed and stored, a huge hydrogen storage device is required; however, when the generated hydrogen is compressed and stored, the internal pressure of the gas collecting pipeline between the hydrogen production reactor and the compression pump will drop, causing the gas collecting pipe There is a large pressure difference between the pipeline and the reactor, so that the culture solution in the reactor flows into the gas collection pipeline. 2. The hydrogen generated in the reactor makes more bubbles appear on the top of the reactor, and some of the bubbles will enter the gas collection pipe with the hydrogen and cause corrosion to the gas collection pipe. Therefore, it is necessary to separate the process of collecting hydrogen from the process of compressing hydrogen .

Contents of the invention

In order to overcome the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a method for hydrogen production by continuous reaction of photosynthetic bacteria.

The present invention is achieved through the following technical solutions.

A continuous reaction hydrogen production method of photosynthetic bacteria, the method is to use photosynthetic bacteria continuous hydrogen production reaction device for cell culture and reaction hydrogen production;

The photosynthetic bacteria continuous hydrogen production reaction device is that one end of the reactor is connected with a residual liquid treatment tank, and is connected with the other end of the reactor through a peristaltic liquid inlet pump; the upper part of the reactor is connected with a hydrogen collection device, a high-concentration product Hydrogen culture solution tank, photosynthetic bacteria culture device and PH regulator tank; a constant temperature water tank is provided on the outer bottom end of the reactor to communicate with a solar water heater through a clean water pump; the feed pump and clean water pump are controlled by a computer; the reactor is controlled by The liquid inlet shell, the transparent reaction shell and the liquid outlet shell are sequentially arranged in a connected seal structure, and a microporous filter membrane I is arranged between the liquid inlet shell and the reaction shell, and a microporous filter membrane I is set between the reaction shell and the liquid outlet shell. There is a microporous filter membrane II; a stirrer is arranged in the reaction shell. .

The culture and reaction of the bacteria is that after the photosynthetic bacteria are cultured and multiplied until the OD _660nm reaches 1.6-1.9, 4/5-5/6 of the bacteria liquid is concentrated by volume through a microporous filter membrane III with a pore size of ≤0.22 μm. The concentration of the bacterial solution reaches 2 to 3 times that of the original bacterial solution, and the concentrated bacterial solution is injected into the reactor under computer control for photosynthetic hydrogen production and stored in the hydrogen collection device (5); the unconcentrated bacterial solution is added with new After the culture medium was removed, the proliferation culture was continued.

Further additional technical features of the above technical solution are as follows.

The hydrogen gas collecting device is connected with the gas collecting tank Ⅰ through the water pool; .

The photosynthetic bacteria culture device is connected with an incubator and a concentration box through a pump, and a microporous filter membrane with a pore size of ≤0.22 μm is provided at a 4/5 to 5/6 box length from the entrance of the bacteria solution in the concentration box Ⅲ.

The material of the microporous membrane I, the microporous membrane II and the microporous membrane III is polytetrafluoroethylene or polyethersulfone.

The transparent reaction shell is made of glass or resin material.

The present invention provides a continuous reaction method for hydrogen production by photosynthetic bacteria. Compared with the existing method, the microporous filter membrane at the front of the reactor prevents the miscellaneous bacteria in the liquid flowing into the liquid inlet casing from entering the reaction casing; therefore , in the case of ensuring that the photosynthetic bacteria in the photosynthetic bacteria culture device are not polluted, it is only necessary to use a sterilized high-concentration culture solution and a pH regulator, so that there are no microorganisms other than photosynthetic bacteria in the reaction shell, avoiding It eliminates the influence of miscellaneous bacteria on the hydrogen production of photosynthetic bacteria, and only sterilizes the high-concentration culture solution and pH regulator, requiring less energy consumption. The microporous membrane at the back of the reactor is used to separate the photosynthetic bacteria from the effluent, so that the number of photosynthetic bacteria in the reactor remains stable, which is conducive to ensuring the stability and efficiency of hydrogen production in the reactor; at the same time, reducing The consumption of substrate by microbial proliferation is reduced, thereby increasing the efficiency of substrate conversion into hydrogen.

In the method of the invention, the raffinate flowing out from the rear of the reactor is passed through a raffinate treatment pool to remove substances produced by the metabolism of photosynthetic bacteria that inhibit the hydrogen production of photosynthetic bacteria, and then enters the reactor through a peristaltic liquid inlet pump. Therefore, the hydrogen production activity of photosynthetic bacteria is improved, and at the same time, the unused substrate in the raffinate enters the reactor again to participate in the reaction, and the utilization rate of the substrate is improved.

In the method of the invention, the hot water in the solar water heater is passed into the constant temperature water tank provided on the outer bottom end of the reactor, so that the temperature of the liquid in the reactor is stabilized within the temperature range where photosynthetic bacteria efficiently produce hydrogen, and at the same time, the solar water heater utilizes the pollution-free The solar energy is conducive to energy saving and emission reduction.

The method of the present invention detects the density of photosynthetic bacteria in the reactor, the concentration of the substrate, the temperature and pH of the liquid in real time through the detection device, and feeds back the signal to the computer, so that the computer can adjust the high-concentration hydrogen-producing culture solution, concentrated bacterial solution, and pH adjustment in real time. The intake of reagent and hot water can keep the condition of hydrogen production in the best state.

The method of the present invention uses two gas collection tanks to collect hydrogen in turn, and by switching the relevant valves on the gas collection pipeline and the compression pipeline, the purpose of gas collection and gas compression not affecting each other can be achieved, so that the compressed gas does not affect the gas collection pipeline. pressure. The two gas collection tanks are used to collect hydrogen in turn, which ensures the continuity of gas collection and provides sufficient time for compressed gas. Use the drainage method to collect hydrogen, drain the water in the gas collecting tank into the pool, compress and store the hydrogen filled in the gas collecting tank, the pressure inside the gas collecting tank will drop, and then open the valve on the pipeline connecting the gas collecting tank and the pool. The gas collection tank is automatically refilled with water for the next gas collection. This method is easy to operate and can realize repeated gas collection.

The method of the present invention separates the photosynthetic bacteria and most of the growth medium through the microporous filter membrane III in the concentration box, thereby reducing the adverse effect of the growth medium on the hydrogen production of the photosynthetic bacteria; at the same time, reinjecting the separated growth medium The incubator is used for the proliferation of photosynthetic bacteria and improves the utilization rate of the growth medium.

Description of drawings

Fig. 1 is the structural representation of the photosynthetic bacteria continuous hydrogen production reaction device that the method of the present invention adopts.

Fig. 2 is a schematic structural view of the reactor in Fig. 1 .

FIG. 3 is a schematic structural view of the liquid inlet housing 25 in FIG. 2 .

FIG. 4 is a schematic structural view of the liquid outlet housing 15 in FIG. 2 .

FIG. 5 is a schematic structural view of the reaction housing 26 in FIG. 2 .

FIG. 6 is a top view of the gas collecting port 21 in FIG. 2 .

Fig. 7: Schematic diagram of the structure of the gas collecting device 5 in Fig. 1 .

Fig. 8: Schematic diagram of the structure of the photosynthetic bacteria culture device 7 in Fig. 1 .

In the figure: 1: reactor; 2: residual liquid treatment pool; 3: constant temperature water tank; 4: solar water heater; 5: hydrogen collection device; 6: high-concentration hydrogen production culture solution tank; 7: photosynthetic bacteria cultivation device; PH regulator box; 9: feed pump; 10: computer; 11: liquid inlet pump; 12: clean water pump; 13: detection device; 14: agitator; 15: liquid outlet shell; 16: microporous membrane Ⅰ ;17: flange; 18: nut; 18: feed port; 19: feed port; 20: detection port; 21: gas collection port; 22: liquid inlet; 23: liquid outlet; 24: microporous filter Membrane Ⅱ; 25: liquid inlet shell; 26: reaction shell; 27: gas collection tank Ⅰ; 28: hydrogen storage tank; 29: compression pump; 30: valve; 31: valve; 32: valve; 33: valve; 34: valve; 35: valve; 36: pool; 37: hydrogen purification drying box; 38: gas collection tank II; 39: microporous membrane III; 40: injection port; 41: liquid outlet; 42: liquid outlet ; 43: liquid inlet; 44: incubator; 45: pump; 46: concentration box.

Detailed ways

First, through the injection port 40 of the incubator 44 in the photosynthetic bacteria culture device 7 after sterilization, the photosynthetic bacteria liquid and the growth medium with a volume ratio of 1:4 are injected in the incubator 44 to carry out proliferation and cultivation. After the bacterial concentration OD _660nm in the incubator reaches 1.6-1.9, 4/5-5/6 of the bacterial liquid by volume is transported into the concentration tank 46 by the pump 45, and the concentration tank 46 is separated from the bacterial liquid inlet 4 Concentrate with microporous membrane III 39 with a pore size of ≤0.22 μm at the length of the box at 5 to 5/6, and stop concentrating when the concentration of the bacterial solution reaches 2 to 3 times the concentration of the original bacterial solution. The separated culture solution is returned to the incubator 44 through the liquid inlet 43, and new culture solution is added through the injection port 40 to continue to proliferate and cultivate the photosynthetic bacteria, realizing the continuous cycle of photosynthetic bacteria proliferation, cultivation and concentration. Then turn on the liquid inlet pump 11 to inject water into the liquid inlet housing 25 through the liquid inlet 22, and enter the water in the liquid inlet housing 25, and then filter out miscellaneous bacteria through the microporous filter membrane I16 with a pore size of ≤0.22 μm and enter Inside the sterilized reaction housing 26. Then turn on the computer 10, the agitator 14 and the detection device 13, and by the signal fed back by the detection device 13, the computer 10 automatically controls the feed pump 9 to transfer the high-concentration culture solution and the pH regulator tank 8 in the high-concentration hydrogen production culture solution tank 6 The pH regulator inside and the bacteria solution concentrated by the microporous membrane III39 are injected into the reaction shell 26 through the feed port 19, and stirred by the agitator 14, the water, photosynthetic bacteria and culture fluid in the reaction shell are mixed Uniformity, so that the OD _660nm concentration of the bacterial solution in the reaction shell 26 reaches 0.2-0.5, the concentration of the culture solution is stable at the concentration when photosynthetic bacteria normally produce hydrogen, and the pH value is stable at 6.5-7.5; at the same time, the computer 10 controls the clean water pump 12 to The hot water in the solar water heater 4 is injected into the constant temperature water tank 3 provided on the outer bottom end surface of the reactor 1, and the mixed liquid in the reactor 1 is heated to 25-30°C. Further, the photosynthetic bacteria in the reaction housing 26 absorb and utilize the nutrients in the hydrogen production culture solution and the light energy passing through the reaction housing 26 to produce hydrogen, and the generated hydrogen enters the hydrogen gas collection device 5 through the gas collection port 21 . The hydrogen-producing culture fluid used by photosynthetic bacteria passes through the microporous filter membrane II 24 with a pore size of ≤0.22 μm to filter out the photosynthetic bacteria, enters the liquid outlet shell 15, and then flows into the residual liquid treatment tank 2 through the liquid outlet 23 to remove the hydrogen-producing photosynthetic bacteria After the process and the substances that inhibit the hydrogen production of photosynthetic bacteria produced during the autolysis of some dead photosynthetic bacteria, they flow into the reactor 1 again through the liquid inlet pump 11 to participate in the reaction.

When the hydrogen gas enters the hydrogen gas collection device 5, the valves 33 and 35 are first opened, and other valves of the gas collection device 5 are closed, and the hydrogen gas enters the gas collection tank I27 through the valve 35, so that the water in the gas collection tank I27 flows into the pool through the valve 33 36. After the gas collection tank I27 is full of hydrogen, close the valves 33 and 35, open the valves 32 and 34, and use the gas collection tank II38 to collect hydrogen. Then open the valve 31 to make the hydrogen in the gas collection tank I27 pass through the hydrogen purification drying box 37 to purify and dry, and then use the compression pump 29 to compress it into the hydrogen storage tank 28. Then close the valve 31, open the valve 33 so that the water in the pool fills the gas collection tank I27 again, and when the gas collection tank II38 is full of hydrogen, change to the gas collection tank I27 to collect hydrogen, and use the hydrogen in the gas collection tank II38 The above method is compressed and stored in the hydrogen storage tank 28, and the continuous hydrogen storage is realized through the gas collection method as described above.

Claims (5)

1. A photosynthetic bacteria continuous reaction hydrogen production method, said method is to adopt photosynthetic bacteria continuous hydrogen production reaction device to carry out thalline culture and reaction hydrogen production; In the photosynthetic bacteria continuous hydrogen production reaction device, one end of the reactor (1) is connected to a raffinate treatment tank (2), and is connected to the other end of the reactor (1) through a peristaltic liquid inlet pump (11); The upper part of the reactor (1) is connected with a hydrogen collection device (5), a high-concentration hydrogen-producing culture solution tank (6), a photosynthetic bacteria culture device (7) and a pH regulator tank (8); outside the reactor (1) The bottom surface is provided with a constant temperature water tank (3), which is connected to a solar water heater (4) through a clean water pump (12); the feed pump (9) and the clean water pump (12) are controlled by a computer (10); the reactor (1) is It is composed of the liquid inlet shell (25), the transparent reaction shell (26) and the liquid outlet shell (15) which are connected and sealed in sequence, and a micro Porous filter membrane I (16), microporous filter membrane II (24) is set between the reaction shell (26) and the liquid outlet shell (15); a stirrer (14) is set in the reaction shell (26) ; The bacteria culture and reaction hydrogen production is that after the photosynthetic bacteria are cultured and multiplied until the OD _660nm reaches 1.6-1.9, 4/5-5/6 of the bacteria liquid is passed through the microporous membrane III with a pore size of ≤0.22 μm by volume ( 39) Concentrate until the concentration of the bacterial solution reaches 2 to 3 times the concentration of the original bacterial solution, and the concentrated bacterial solution is injected into the reactor (1) under the control of the computer (10) for photosynthetic hydrogen production and stored in the hydrogen collection device (5) Medium; the unconcentrated bacterial solution continued to proliferate after adding new culture solution. 2. The method for producing hydrogen by continuous reaction of photosynthetic bacteria according to claim 1, wherein the hydrogen collection device (5) is connected to the gas collection tank II (38) by the gas collection tank I (27) through the water pool (36) ; Gas collecting tank I (27) and gas collecting tank II (38) are respectively connected to the reactor (1), and both are connected to the compression pump (29) and the hydrogen storage tank (28) through the hydrogen purification drying box (37). 3. The photosynthetic bacteria continuous reaction hydrogen production method according to claim 1, wherein the photosynthetic bacteria culture device (7) is connected with an incubator (44) and a concentration tank (46) through a pump (45), and the concentrated A microporous filter membrane III (39) with a pore diameter of ≤0.22 μm is arranged in the box (46) 4/5 to 5/6 of the box length away from the bacterial liquid inlet. 4. The photosynthetic bacteria continuous reaction hydrogen production method according to claim 1 or 3, the materials of the microporous membrane I (16), microporous membrane II (24) and microporous membrane III (39) It is polytetrafluoroethylene or polyethersulfone. 5. The method for continuously reacting hydrogen production by photosynthetic bacteria according to claim 1, wherein the concentration of the hydrogen-producing culture solution in the high-concentration hydrogen-producing culture solution tank (6) is 3 times the concentration of the culture solution when the photosynthetic bacteria produce hydrogen normally. ~5 times.