A method for producing hydrogen and electricity using biomass

Abstract

The present invention belongs to the field of microbial energy technology, and specifically relates to a method for producing hydrogen and electricity using biomass. The present invention selects Anaerobic Bacillus saccharolyticus, which is easy to culture. It can not only use a variety of sugars as raw materials, but also convert a large amount of biomass into hydrogen energy and electrical energy, thereby realizing efficient resource utilization of lignocellulose. At the same time, the non-detoxified hydrolyzate is directly used as an electron donor, and after a simple dilute acid treatment, it can be used in microbial fuel cells, avoiding the pollution caused by the detoxification process to the environment. The process steps are simple and easy to operate. Only a single strain needs to be added, and it has good application prospects. The synchronous hydrogen and electricity production process adopted by the present invention can significantly improve the utilization efficiency of the hydrolyzate and further increase the hydrogen production and electricity production.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbial energy, and specifically relates to a method for producing hydrogen and electricity using biomass. Background Art

[0002] The increasing energy shortages and environmental pollution caused by the massive consumption of fossil fuels have drawn widespread international attention. To mitigate the adverse environmental and climate impacts of the rapid depletion of fossil fuels, researchers worldwide are actively engaged in research on sustainable energy. my country, a traditionally agricultural country, possesses abundant biomass resources. Biomass, a readily available, low-cost resource with high value-added potential, can be converted into energy to alleviate the energy crisis caused by the widespread use of fossil fuels.

[0003] Microbial fuel cells operate by utilizing electrochemically active microorganisms to metabolize substrates, converting organic matter into electrical energy. Not only are they pollution-free, with mild reaction conditions and a wide range of substrate sources, they represent a novel, green energy generation method and have garnered widespread attention from researchers. However, microbial fuel cells are constrained by the electrochemical activity of the microorganisms, and different electricity-producing microorganisms exhibit distinct differences due to their differing mechanisms for electron generation and electron transfer. Furthermore, current microbial fuel cell technology utilizes pure compounds, such as glucose, lactic acid, and acetic acid, to generate electricity, resulting in relatively high application costs.

[0004] Prior art discloses a Klebsiella pneumoniae-like strain and its use in a microbial fuel cell. This method tests the electrochemical activity of the screened Klebsiella pneumoniae-like strain and explores its ability to produce electron mediators and form biofilms for extracellular electron transfer. However, this strain still generates electricity from pure compounds, and the rate of electricity generation is relatively slow.

[0005] Prior art also discloses a method for generating electricity through continuous microbial fermentation of corn straw hydrolyzate. This method converts agricultural waste, corn straw, into electricity through bioengineering, achieving both green electricity generation and efficient resource utilization of agricultural waste. However, this method relies on the combined action of fermentation bacteria and electrogenic bacteria to produce electricity, resulting in complex process steps. The resulting fermentation liquid does not fully meet the cultivation requirements of the electrogenic bacteria, and its substrate conversion rate is relatively low. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for producing hydrogen and electricity using biomass. The method provided by the present invention has a simple process and a higher effect of producing hydrogen and electricity.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a method for producing hydrogen and electricity using biomass, comprising the following steps:

[0009] Acid hydrolyzing the biomass to obtain a hydrolyzate, wherein the hydrolyzate contains sugar compounds and has not been detoxified;

[0010] Activate the thermophilic anaerobic bacillus saccharolyticus to obtain seed liquid;

[0011] The hydrolyzate is used as a carbon source, and a culture medium containing the hydrolyzate is injected into the anode chamber of a dual-chamber microbial fuel cell as an anode liquid. After sterilization, the seed liquid is inoculated into the anode liquid to produce hydrogen and electricity under anaerobic conditions.

[0012] Preferably, the acid hydrolysis process is: mixing the biomass and an acidic liquid for acid hydrolysis; the acidic liquid is a sulfuric acid solution; the mass concentration of the acidic liquid is 0.5-4%;

[0013] The ratio of the biomass to the acidic liquid is 10 g: 50-150 mL;

[0014] The acid decomposition temperature is 112-130° C., and the time is 15-45 minutes.

[0015] Preferably, the thermophilic anaerobic bacterium saccharolyticum is thermophilic anaerobic bacterium saccharolyticum MJ2, and its deposit number is GDMCC No: 61394.

[0016] Preferably, the seed culture medium used for activation comprises the following components: 5-15 g / L xylan, 1-1.6 g / L ammonium sulfate, 2-3.2 g / L magnesium chloride hexahydrate, 1.41-1.45 g / L potassium dihydrogen phosphate, 5.2-5.8 g / L dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L calcium chloride dihydrate, 4-8 g / L sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L reduced glutathione, 4.2-4.8 g / L yeast powder, 0.5-1.5 g / L ferric chloride hexahydrate, and 0.9-1.3 mL / L ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%;

[0017] The pH value of the seed culture medium is 6.8-7.2.

[0018] Preferably, the activation process comprises: adding seed culture medium into a serum bottle, evacuating and filling with inert gas, sterilizing, and inoculating the thermophilic anaerobic bacillus saccharolyticus to activate;

[0019] The activation temperature is 50-60° C., and the activation is carried out under oscillation conditions. The oscillation speed is 120-180 rpm, and the activation time is 16-20 hours.

[0020] Preferably, the hydrolyzate comprises the following components, calculated based on the total sugar concentration: 5-15 g / L of hydrolyzate, 1-1.6 g / L of ammonium sulfate, 2-3.2 g / L of magnesium chloride hexahydrate, 1.41-1.45 g / L of potassium dihydrogen phosphate, 5.2-5.8 g / L of dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L of calcium chloride dihydrate, 4-8 g / L of sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L of reduced glutathione, 4.2-4.8 g / L of yeast powder, and 0.9-1.3 mL / L of ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%;

[0021] The pH value of the anolyte is 6.8-7.2.

[0022] Preferably, the cathode chamber of the dual-chamber microbial fuel cell comprises a cathode liquid, the cathode liquid comprises a phosphate buffer containing potassium ferrocyanide, the concentration of the potassium ferrocyanide is 40 to 60 mmol / L, and the pH value of the phosphate buffer is 6.8 to 7.2.

[0023] Preferably, the inoculation amount of the seed solution in the anolyte is 5-15 v / v%; the volume ratio of the anolyte to the cathode solution is 1:1.

[0024] Preferably, the anode chamber further includes an anode, and the cathode chamber further includes a cathode;

[0025] The anode and cathode are both conductive carbon paper; the anode and cathode have the same size;

[0026] The anode and cathode are connected via a resistance load;

[0027] The anode chamber and the cathode chamber are separated by a proton exchange membrane.

[0028] Preferably, the temperature for producing hydrogen and electricity is 50-60° C., and the hydrogen and electricity are produced under oscillation conditions, the oscillation speed is 120-180 rpm, and the time is 20-28 hours.

[0029] The present invention provides a method for producing hydrogen and electricity using biomass, comprising the following steps: subjecting biomass to acid hydrolysis to obtain a hydrolyzate, wherein the hydrolyzate contains sugar compounds and has not been detoxified; activating thermophilic anaerobic bacillus saccharolyticus to obtain a seed solution; using the hydrolyzate as a carbon source, injecting a culture medium containing the hydrolyzate as an anolyte into the anode chamber of a dual-chamber microbial fuel cell, sterilizing the culture medium, inoculating the seed solution into the anolyte, and producing hydrogen and electricity under anaerobic conditions.

[0030] The present invention has the following beneficial effects compared to the prior art:

[0031] (1) The present invention selects thermophilic anaerobic bacillus saccharolyticus, which is easy to culture and can not only use a variety of organic matter as raw materials, but also convert a large amount of biomass into hydrogen energy and electrical energy, thereby achieving efficient resource utilization of lignocellulose.

[0032] (2) The present invention directly uses the undetoxified hydrolyzate as an electron donor, which can be used in microbial fuel cells after a simple dilute acid treatment, thus avoiding the pollution to the environment caused by the detoxification process. The process steps are simple and easy to operate, and only a single strain needs to be added, which has good application prospects.

[0033] (3) The simultaneous hydrogen and electricity production process employed in this invention significantly improves the utilization efficiency of the hydrolyzate, further increasing both hydrogen and electricity production, with a maximum output voltage reaching 321.2 mV and a hydrogen yield of 101.9 mM. This method not only enriches the diversity of electricity-producing microorganisms but also expands the resource utilization pathways for lignocellulose, laying the foundation for the application of microbial fuel cells in the field of lignocellulose energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The Gram staining results (left) and transmission electron micrograph (right) of the strain Anaerobic Bacillus thermosaccharolyticus MJ2 of the present invention are shown;

[0035] Figure 2 The cyclic voltammetry curves of the microbial fuel cells obtained in Example 1 and Comparative Examples 1 to 3 when performing redox species detection;

[0036] Figure 3 The differential pulse voltammetry curves of the microbial fuel cells obtained in Example 1 and Comparative Examples 1 to 3 when performing redox species detection;

[0037] Figure 4 This is a scanning electron microscope image of the anode in Example 1 after producing hydrogen and electricity. DETAILED DESCRIPTION

[0038] The present invention provides a method for producing hydrogen and electricity using biomass, comprising the following steps:

[0039] Acid hydrolyzing the biomass to obtain a hydrolyzate, wherein the hydrolyzate includes sugar compounds and has not been detoxified;

[0040] Activate the thermophilic anaerobic bacillus saccharolyticus to obtain seed liquid;

[0041] The hydrolyzate is used as a carbon source, and a culture medium containing the hydrolyzate is injected into the anode chamber of a dual-chamber microbial fuel cell as an anode liquid. After sterilization, the seed liquid is inoculated into the anode liquid to produce hydrogen and electricity under anaerobic conditions.

[0042] The present invention performs acid hydrolysis on biomass to obtain a hydrolyzate containing sugar compounds.

[0043] In the present invention, the biomass is preferably garden waste. The present invention has no particular limitation on the source of the garden waste, and any source known to those skilled in the art can be used.

[0044] In the present invention, the acid hydrolysis process is preferably as follows: mixing biomass and an acidic liquid for acid hydrolysis; the acidic liquid is preferably a sulfuric acid solution; the mass concentration of the acidic liquid is preferably 0.5-4%, more preferably 1%; the amount ratio of the biomass to the acidic liquid is preferably 10g:50-150mL, more preferably 10g:100mL. In the present invention, the acid hydrolysis temperature is preferably 112-130°C, more preferably 121°C, and the time is preferably 15-45 minutes, more preferably 30 minutes.

[0045] After the acid hydrolysis, the present invention preferably further comprises filtering the obtained acid hydrolysis system. In the present invention, the system after acid hydrolysis is only subjected to simple filtration and impurity removal without detoxification treatment. The hydrolyzate that has not been detoxified can also achieve good hydrogen and electricity production. On the one hand, it simplifies the process steps, while also avoiding the pollution caused by the detoxification process to the environment, thereby making the method provided by the present invention have better application prospects.

[0046] The invention activates the thermophilic anaerobic bacillus saccharolyticus to obtain seed liquid.

[0047] In the present invention, the thermophilic anaerobic bacterium saccharolyticum is preferably thermophilic anaerobic bacterium saccharolyticum MJ2, with a deposit number of GDMCC No: 61394.

[0048] In the present invention, the seed culture medium used for activation preferably comprises the following ingredients: 5-15 g / L xylan, 1-1.6 g / L ammonium sulfate, 2-3.2 g / L magnesium chloride hexahydrate, 1.41-1.45 g / L potassium dihydrogen phosphate, 5.2-5.8 g / L dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L calcium chloride dihydrate, 4-8 g / L sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L reduced glutathione, 4.2-4.8 g / L yeast powder, 0.5-1.5 g / L ferric chloride hexahydrate, 0.9-1.3 g / L ferrous sulfate heptahydrate solution. L / L, the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%, and more preferably: xylan 10g / L, ammonium sulfate 1.3g / L, magnesium chloride hexahydrate 2.6g / L, potassium dihydrogen phosphate 1.43g / L, dipotassium hydrogen phosphate trihydrate 5.5g / L, calcium chloride dihydrate 0.13g / L, sodium β-glycerophosphate pentahydrate 6g / L, reduced glutathione 0.25g / L, yeast powder 4.5g / L, ferric chloride hexahydrate 1g / L, and ferrous sulfate heptahydrate solution 1.1mL / L; the pH value of the seed culture medium is preferably 6.8-7.2, and more preferably 7.0.

[0049] In the present invention, the activation process preferably includes: adding seed culture medium to a serum bottle, evacuating and filling with inert gas, inoculating the thermophilic anaerobic saccharolytic bacteria after sterilization, and activating. In the present invention, the inert gas is preferably nitrogen. The present invention has no special limitation on the sterilization process, and the method well known to those skilled in the art can be used. In the present invention, the activation temperature is preferably 50-60°C, more preferably 55°C, and the activation is preferably carried out under shaking conditions, the shaking speed is preferably 120-180rpm, more preferably 150rpm, and the time is preferably 16-20h, more preferably 18h.

[0050] After obtaining the hydrolyzate and seed liquid, the present invention uses the hydrolyzate as a carbon source, injects a culture medium containing the hydrolyzate as an anode liquid into the anode chamber of a dual-chamber microbial fuel cell, and after sterilization, inoculates the seed liquid into the anode liquid to produce hydrogen and electricity under anaerobic conditions.

[0051] In the present invention, the hydrolyzate is calculated based on the total sugar concentration, and the anolyte preferably includes the following components: 5-15 g / L of hydrolyzate, 1-1.6 g / L of ammonium sulfate, 2-3.2 g / L of magnesium chloride hexahydrate, 1.41-1.45 g / L of potassium dihydrogen phosphate, 5.2-5.8 g / L of dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L of calcium chloride dihydrate, 4-8 g / L of sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L of reduced glutathione, 4.2-4.8 g / L of yeast powder, and 0.9-1.3 g / L of ferrous sulfate heptahydrate solution. L / L, the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%, more preferably 10 g / L of hydrolyzate, 1.3 g / L of ammonium sulfate, 2.6 g / L of magnesium chloride hexahydrate, 1.43 g / L of potassium dihydrogen phosphate, 5.5 g / L of dipotassium hydrogen phosphate trihydrate, 0.13 g / L of calcium chloride dihydrate, 6 g / L of sodium β-glycerophosphate pentahydrate, 0.25 g / L of reduced glutathione, 4.5 g / L of yeast powder, and 1.1 mL / L of ferrous sulfate heptahydrate solution; the pH value of the anolyte is preferably 6.8-7.2, more preferably 7.0.

[0052] In the present invention, the cathode chamber of the dual-chamber microbial fuel cell preferably includes a cathode liquid, and the cathode liquid preferably includes a phosphate buffer containing potassium ferrocyanide. The concentration of the potassium ferrocyanide is preferably 40 to 60 mmol / L, more preferably 50 mmol / L, and the pH value of the phosphate buffer is preferably 6.8 to 7.2, more preferably 7.0.

[0053] In the present invention, the inoculation amount of the seed solution in the anolyte is preferably 5-15 v / v%, more preferably 10 v / v%; the volume ratio of the anolyte to the catholyte is preferably 1:1. In the present invention, the anolyte chamber also preferably includes an anode, and the cathode chamber also preferably includes a cathode; the anode and cathode are preferably both conductive carbon paper; the dimensions of the anode and cathode are preferably the same, and the dimensions are specifically preferably 15×15×0.2 mm. In the present invention, the anode and cathode are preferably connected via a resistive load; the resistance of the resistive load is preferably 2 kΩ. In the present invention, the anolyte chamber and the cathode chamber are preferably separated by a proton exchange membrane, and the proton exchange membrane is preferably a DuPont Nafion-117 membrane.

[0054] In the present invention, the sterilization temperature is preferably 115° C., and the sterilization time is preferably 20 minutes.

[0055] In the present invention, the temperature for producing hydrogen and electricity is preferably 50-60°C, more preferably 55°C, and the hydrogen and electricity production is preferably carried out under oscillation conditions. The oscillation speed is preferably 120-180rpm, more preferably 150rpm, and the time is preferably 20-28h, more preferably 24h.

[0056] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0057] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Example 1

[0059] The garden waste was mixed with a sulfuric acid solution having a mass concentration of 1%, wherein the amount ratio of the garden waste to the sulfuric acid solution was 10 g: 100 mL, and acid hydrolyzed at 121° C. for 30 min, and the hydrolyzed solution was obtained after filtration;

[0060] A seed culture medium was added to a serum bottle, which was evacuated and filled with nitrogen for sterilization; wherein the seed culture medium comprised the following components: 10 g / L xylan, 1.3 g / L ammonium sulfate, 2.6 g / L magnesium chloride hexahydrate, 1.43 g / L potassium dihydrogen phosphate, 5.5 g / L dipotassium hydrogen phosphate trihydrate, 0.13 g / L calcium chloride dihydrate, 6 g / L sodium β-glycerophosphate pentahydrate, 0.25 g / L reduced glutathione, 4.5 g / L yeast extract, 1 g / L ferric chloride hexahydrate, and 1.1 mL / L ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution was 0.1%; the pH value of the seed culture medium was 7.0; Thermosaccharolytic anaerobic bacillus MJ2 was inoculated into the serum bottle, and the serum bottle was placed in a shaker for oscillation activation at a temperature of 55° C. and a rotation speed of 150 rpm for 18 hours to obtain a seed solution;

[0061] The obtained hydrolyzate is used as a carbon source to prepare an anolyte. The hydrolyzate is calculated based on the total sugar concentration. The anolyte comprises the following components: 10 g / L of hydrolyzate, 1.3 g / L of ammonium sulfate, 2.6 g / L of magnesium chloride hexahydrate, 1.43 g / L of potassium dihydrogen phosphate, 5.5 g / L of dipotassium hydrogen phosphate trihydrate, 0.13 g / L of calcium chloride dihydrate, 6 g / L of sodium β-glycerophosphate pentahydrate, 0.25 g / L of reduced glutathione, 4.5 g / L of yeast powder, and 1.1 mL / L of ferrous sulfate heptahydrate solution. The mass concentration of the ferrous sulfate heptahydrate solution is preferably 0.1%. The pH value of the anolyte is 7.0.

[0062] A dual-chamber microbial fuel cell was constructed using a phosphate buffer solution containing potassium ferrocyanide at a concentration of 50 mmol / L and a pH of 7.0 as the cathode liquid. DuPont Nafion-117 membrane was used as the proton exchange membrane, and conductive carbon paper was used as the cathode and anode, each with dimensions of 15 × 15 × 0.2 mm. A 2 kΩ resistor load was connected between the cathode and anode.

[0063] 90 mL of anolyte was injected into the anode chamber, and 100 mL of catholyte was injected into the cathode chamber. Nitrogen was simultaneously filled into the cathode and anode chambers for 30 minutes to place the two chambers in an anaerobic environment. After sterilization at 115°C for 20 minutes, 10 mL of seed solution was inoculated into the anolyte. The microbial fuel cell was then placed in a shaker and shaken at a temperature of 55°C and a speed of 150 rpm for 24 hours to produce hydrogen and electricity in the first cycle.

[0064] After oscillating for 24 h, 90% of the liquid in the anode chamber and cathode chamber was removed, and the same volume of new anode liquid and cathode liquid were added to 100 mL respectively, and nitrogen was refilled. The oscillation was continued at a temperature of 55 ° C and a rotation speed of 150 rpm for 24 h to complete the second cycle of hydrogen and electricity production.

[0065] Example 2

[0066] The garden waste was mixed with a sulfuric acid solution having a mass concentration of 2%, wherein the amount ratio of the garden waste to the sulfuric acid solution was 10 g: 80 mL, and the mixture was acid-hydrolyzed at 115° C. for 20 min, and the hydrolyzate was obtained after filtration;

[0067] A seed culture medium was added to a serum bottle, which was evacuated and filled with nitrogen for sterilization; wherein the seed culture medium comprised the following components: 10 g / L xylan, 1.3 g / L ammonium sulfate, 2.6 g / L magnesium chloride hexahydrate, 1.43 g / L potassium dihydrogen phosphate, 5.5 g / L dipotassium hydrogen phosphate trihydrate, 0.13 g / L calcium chloride dihydrate, 6 g / L sodium β-glycerophosphate pentahydrate, 0.25 g / L reduced glutathione, 4.5 g / L yeast extract, 1 g / L ferric chloride hexahydrate, and 1.1 mL / L ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution was 0.1%; the pH value of the seed culture medium was 7.0; Thermosaccharolytic anaerobic bacillus MJ2 was inoculated into the serum bottle, and the serum bottle was placed in a shaker for oscillation activation at a temperature of 55° C. and a rotation speed of 120 rpm for 16 hours to obtain a seed solution;

[0068] The obtained hydrolyzate is used as a carbon source to prepare an anolyte. The hydrolyzate is calculated based on the total sugar concentration. The anolyte comprises the following components: 10 g / L of hydrolyzate, 1.3 g / L of ammonium sulfate, 2.6 g / L of magnesium chloride hexahydrate, 1.43 g / L of potassium dihydrogen phosphate, 5.5 g / L of dipotassium hydrogen phosphate trihydrate, 0.13 g / L of calcium chloride dihydrate, 6 g / L of sodium β-glycerophosphate pentahydrate, 0.25 g / L of reduced glutathione, 4.5 g / L of yeast powder, and 1.1 mL / L of ferrous sulfate heptahydrate solution. The mass concentration of the ferrous sulfate heptahydrate solution is preferably 0.1%. The pH value of the anolyte is 7.0.

[0069] A dual-chamber microbial fuel cell was constructed using a phosphate buffer solution containing potassium ferrocyanide at a concentration of 50 mmol / L and a pH of 7.0 as the cathode liquid. DuPont Nafion-117 membrane was used as the proton exchange membrane, and conductive carbon paper was used as the cathode and anode, each with dimensions of 15 × 15 × 0.2 mm. A 2 kΩ resistor load was connected between the cathode and anode.

[0070] 80 mL of anolyte was injected into the anode chamber, and 100 mL of catholyte was injected into the cathode chamber. Nitrogen was simultaneously filled into the cathode and anode chambers for 30 minutes to place the two chambers in an anaerobic environment. After sterilization at 115°C for 20 minutes, 20 mL of seed solution was inoculated into the anolyte. The microbial fuel cell was then placed in a shaker and shaken at a temperature of 55°C and a speed of 150 rpm for 24 hours to produce hydrogen and electricity in the first cycle.

[0071] After oscillating for 24 h, 90% of the liquid in the anode chamber and cathode chamber was removed, and the same volume of new anode liquid and cathode liquid were added to 100 mL respectively, and nitrogen was refilled. The oscillation was continued at a temperature of 55 ° C and a rotation speed of 150 rpm for 24 h to complete the second cycle of hydrogen and electricity production.

[0072] Example 3

[0073] The garden waste was mixed with a sulfuric acid solution having a mass concentration of 3%, wherein the ratio of the garden waste to the sulfuric acid solution was 10 g:120 mL, and the mixture was acid-hydrolyzed at 125°C for 40 minutes, and the hydrolyzate was obtained after filtration;

[0074] A seed culture medium was added to a serum bottle, which was evacuated and filled with nitrogen for sterilization; wherein the seed culture medium comprised the following components: 10 g / L xylan, 1.3 g / L ammonium sulfate, 2.6 g / L magnesium chloride hexahydrate, 1.43 g / L potassium dihydrogen phosphate, 5.5 g / L dipotassium hydrogen phosphate trihydrate, 0.13 g / L calcium chloride dihydrate, 6 g / L sodium β-glycerophosphate pentahydrate, 0.25 g / L reduced glutathione, 4.5 g / L yeast extract, 1 g / L ferric chloride hexahydrate, and 1.1 mL / L ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution was 0.1%; the pH value of the seed culture medium was 7.0; Thermosaccharolytic anaerobic bacillus MJ2 was inoculated into the serum bottle, and the serum bottle was placed in a shaker for oscillation activation at a temperature of 55° C. and a rotation speed of 180 rpm for 20 hours to obtain a seed solution;

[0075] The obtained hydrolyzate is used as a carbon source to prepare an anolyte. The hydrolyzate is calculated based on the total sugar concentration. The anolyte comprises the following components: 10 g / L of hydrolyzate, 1.3 g / L of ammonium sulfate, 2.6 g / L of magnesium chloride hexahydrate, 1.43 g / L of potassium dihydrogen phosphate, 5.5 g / L of dipotassium hydrogen phosphate trihydrate, 0.13 g / L of calcium chloride dihydrate, 6 g / L of sodium β-glycerophosphate pentahydrate, 0.25 g / L of reduced glutathione, 4.5 g / L of yeast powder, and 1.1 mL / L of ferrous sulfate heptahydrate solution. The mass concentration of the ferrous sulfate heptahydrate solution is preferably 0.1%. The pH value of the anolyte is 7.0.

[0076] A dual-chamber microbial fuel cell was constructed using a phosphate buffer solution containing potassium ferrocyanide at a concentration of 50 mmol / L and a pH of 7.0 as the cathode liquid. DuPont Nafion-117 membrane was used as the proton exchange membrane, and conductive carbon paper was used as the cathode and anode, each with dimensions of 15 × 15 × 0.2 mm. A 2 kΩ resistor load was connected between the cathode and anode.

[0077] 95 mL of anolyte was injected into the anode chamber, and 100 mL of catholyte was injected into the cathode chamber. Nitrogen was simultaneously filled into the cathode and anode chambers for 30 minutes to place the two chambers in an anaerobic environment. After sterilization at 115°C for 20 minutes, 5 mL of seed solution was inoculated into the anolyte. The microbial fuel cell was then placed in a shaker and shaken at a temperature of 55°C and a speed of 150 rpm for 24 hours to produce hydrogen and electricity in the first cycle.

[0078] After oscillating for 24 h, 90% of the liquid in the anode chamber and cathode chamber was removed, and the same volume of new anode liquid and cathode liquid were added to 100 mL respectively, and nitrogen was refilled. The oscillation was continued at a temperature of 55 ° C and a rotation speed of 150 rpm for 24 h to complete the second cycle of hydrogen and electricity production.

[0079] Comparative Example 1

[0080] Hydrogen and electricity were produced according to Example 1, except that the hydrolyzate in the anolyte was replaced with xylan.

[0081] Comparative Example 2

[0082] Hydrogen and electricity were produced according to Example 1, except that the hydrolyzate in the anolyte was replaced with xylose.

[0083] Comparative Example 3

[0084] Hydrogen and electricity were produced according to Example 1, except that the hydrolyzate in the anolyte was replaced with arabinose.

[0085] Performance Testing

[0086] Test Example 1

[0087] Morphological characteristics of strains

[0088] (1) Optical microscopic observation of thermophilic anaerobic bacillus saccharolyticus: The strain was cultured in an activated medium until the logarithmic growth phase, and the morphology of the strain was observed under an optical microscope using Gram staining. Figure 1 The Gram staining results (left) and transmission electron micrograph (right) of the strain Anaerobic Bacillus thermosaccharolyticus MJ2 are shown.

[0089] The results showed that the Gram staining result was red, indicating that the thermophilic anaerobic bacillus saccharolyticus MJ2 provided by the present invention was a Gram-negative anaerobic bacterium.

[0090] (2) Transmission electron microscopy observation of Thermoanaerobic Bacillus saccharolyticus: The strain was cultured in an activation medium until the logarithmic growth phase. The cells were centrifuged and fixed with 2.5% glutaraldehyde. The strain morphology was observed under a transmission electron microscope. The results showed that Thermoanaerobic Bacillus saccharolyticus MJ2 was short rod-shaped, 1.5 μm long and 0.25 μm wide, with pili.

[0091] Test Example 2

[0092] For Examples 1 to 3 and Comparative Examples 1 to 3, during the process of hydrogen and electricity generation, a data acquisition device (OW18D intelligent multimeter, Fujian Lilliput Optoelectronics Technology Co., Ltd.) was connected between the anode and cathode to record the output voltage; the results are shown in Table 1;

[0093] For Examples 1 to 3 and Comparative Examples 1 to 3, after the second cycle, the hydrogen production in the anode chamber was measured by gas chromatography; the results are shown in Table 1;

[0094] Table 1 Output voltage and hydrogen production during power generation in Examples 1 to 3 and Comparative Examples 1 to 3

[0095]

[0096] Test Example 3

[0097] The redox substances of the microbial fuel cells obtained in Example 1 and Comparative Examples 1 to 3 were detected;

[0098] Anodic cyclic voltammetry (CV) was measured using an electrochemical workstation (CHI650E, Shanghai Chenhua Instrument Co., Ltd.) with the anode as the working electrode, the cathode as the counter electrode, and Ag / AgCl as the reference electrode. The test conditions were: initial potential of -1.6 V, upper limit potential of 1.6 V, lower limit potential of -1.6 V, sampling interval of 0.001 V, and scan rate of 40 mV / s. Furthermore, anodic differential pulse voltammetry (DPV) was measured using the following test conditions: initial potential of 0.2 V, end point potential of 1.2 V, amplitude of 0.05 V, and pulse width of 0.05 s.

[0099] Figure 2 is the cyclic voltammetry curve; Figure 3 is the differential pulse voltammetry curve;

[0100] Depend on Figure 2 and Figure 3 It can be seen that the cyclic voltammetry curve with the hydrolyzate as the substrate shows a redox peak, and the differential pulse voltammetry curve shows an obvious anodic oxidation peak, indicating that extracellular electron transfer can be carried out through an electron mediator; using xylan as the substrate (Comparative Example 1), compared with the hydrolyzate, the same redox peak can be detected, but its peak intensity is higher than that of the hydrolyzate; using xylose as the substrate (Comparative Example 2), compared with the hydrolyzate, the same redox peak can be detected, and its peak intensity is equivalent to that of the hydrolyzate; using arabinose as the substrate (Comparative Example 3), compared with the hydrolyzate, the same redox peak can be detected, but its peak intensity is lower than that of the hydrolyzate.

[0101] Test Example 4

[0102] In Example 1, after the first cycle and the second cycle, the anode was removed, cut into 2×2 mm pieces, fixed with 2.5% glutaraldehyde, and observed under a scanning electron microscope. Figure 4 The left picture is the scanning electron microscope image of the anode. The right picture is the scanning electron microscope image of the anode after the first cycle. It can be seen that after the end of both cycles, microorganisms can be observed adhering to the anode surface, indicating that the thermophilic anaerobic bacillus saccharolyticus MJ2 can transfer extracellular electrons through biofilm contact.

[0103] In summary, the results indicate that A. thermosaccharolyticus MJ2 is electroactive, capable of extracellular electron transfer through self-synthesized endogenous electron mediators and by forming a biofilm attached to the anode. Furthermore, it can co-produce electricity and hydrogen using a variety of sugars. In particular, when using non-detoxified garden waste hydrolysate as an electron donor, the hydrogen production is comparable to that achieved using xylose as a substrate and higher than that achieved using arabinose as a substrate.

[0104] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for producing hydrogen and electricity using biomass, characterized in that: The following steps are involved: Acid hydrolyzing the biomass to obtain a hydrolyzate, wherein the hydrolyzate contains sugar compounds and has not been detoxified; Activate the thermophilic anaerobic bacillus saccharolyticus to obtain seed liquid; The thermophilic anaerobic bacterium saccharolyticum is thermophilic anaerobic bacterium saccharolyticum MJ2, with a deposit number of GDMCC No: 61394; The hydrolyzate is used as a carbon source, a culture medium containing the hydrolyzate is injected into the anode chamber of a dual-chamber microbial fuel cell as an anolyte, and after sterilization, the seed solution is inoculated into the anolyte to produce hydrogen and electricity under anaerobic conditions; The hydrolyzate is calculated based on the total sugar concentration, and the anolyte includes the following components: 5-15 g / L of hydrolyzate, 1-1.6 g / L of ammonium sulfate, 2-3.2 g / L of magnesium chloride hexahydrate, 1.41-1.45 g / L of potassium dihydrogen phosphate, 5.2-5.8 g / L of dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L of calcium chloride dihydrate, 4-8 g / L of sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L of reduced glutathione, 4.2-4.8 g / L of yeast powder, and 0.9-1.3 mL / L of ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%.

2. The method according to claim 1, characterized in that The acid hydrolysis process is as follows: mixing biomass and acidic liquid for acid hydrolysis; the acidic liquid is a sulfuric acid solution; the mass concentration of the acidic liquid is 0.5% to 4%; The ratio of the biomass to the acidic liquid is 10 g: 50-150 mL; The acid decomposition temperature is 112-130° C., and the time is 15-45 minutes.

3. The method according to claim 1, characterized in that The seed culture medium used for the activation comprises the following components: 5-15 g / L xylan, 1-1.6 g / L ammonium sulfate, 2-3.2 g / L magnesium chloride hexahydrate, 1.41-1.45 g / L potassium dihydrogen phosphate, 5.2-5.8 g / L dipotassium hydrogen phosphate trihydrate, 0.09-0.17 g / L calcium chloride dihydrate, 4-8 g / L sodium β-glycerophosphate pentahydrate, 0.15-0.35 g / L reduced glutathione, 4.2-4.8 g / L yeast powder, 0.5-1.5 g / L ferric chloride hexahydrate, and 0.9-1.3 mL / L ferrous sulfate heptahydrate solution, wherein the mass concentration of the ferrous sulfate heptahydrate solution is 0.1%; The pH value of the seed culture medium is 6.8-7.

2.

4. The method according to claim 3, characterized in that The activation process includes: adding seed culture medium into a serum bottle, evacuating and filling with inert gas, sterilizing, inoculating the thermophilic anaerobic bacillus saccharolyticus, and activating; The activation temperature is 50-60° C., and the activation is carried out under oscillation conditions. The oscillation speed is 120-180 rpm, and the activation time is 16-20 hours.

5. The method according to claim 1, characterized in that The pH value of the anolyte is 6.8-7.

2.

6. The method according to claim 5, characterized in that The cathode chamber of the dual-chamber microbial fuel cell comprises cathode liquid, which comprises a phosphate buffer containing potassium ferrocyanide. The concentration of the potassium ferrocyanide is 40-60 mmol / L, and the pH value of the phosphate buffer is 6.8-7.

2.

7. The method according to claim 5 or 6, characterized in that The inoculation amount of the seed liquid in the anode liquid is 5-15 v / v%; the volume ratio of the anode liquid to the cathode liquid is 1:

1.

8. The method according to claim 1, characterized in that The anode chamber also includes an anode, and the cathode chamber also includes a cathode; The anode and cathode are both conductive carbon paper; the anode and cathode have the same size; The anode and cathode are connected via a resistance load; The anode chamber and the cathode chamber are separated by a proton exchange membrane.

9. The method according to claim 1, characterized in that The temperature for producing hydrogen and electricity is 50-60° C., and the hydrogen and electricity are produced under oscillation conditions. The oscillation speed is 120-180 rpm and the time is 20-28 hours.

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