CN103290425B - Produce hydrogen microorganism electrolysis cell and biological-cathode acclimation method thereof - Google Patents

Abstract

The invention provides a biocathode domestication method of a biocathode type hydrogen-producing microbial electrolytic cell, which is characterized in that it comprises: A) cultivating anode electricity-producing microbial populations in the microbial fuel cell mode, B) cultivating the anode electricity-producing microbial population in the microbial electrolytic cell hydrogen production mode Domestication of anodic hydrogen-phagocytic microbial populations, C) Domestication and cultivation of cathodic hydrogen-producing microorganisms under the three-electrode mode. According to a further aspect of the present invention, the bioanode obtained in the above step A) is combined with the domesticated and cultivated biocathode in the above step C) to form a biocathode type microbial electrolysis cell (400). The present invention also provides a hydrogen-producing biocathode microbial electrolysis cell, which comprises: the bioanode obtained in the above step A), and the biocathode domesticated and cultivated in the above step C).

Description

Hydrogen-producing microbial electrolytic cell and biocathode acclimation method thereof

technical field

The invention belongs to the technical field of microbial electrochemistry, and relates to a hydrogen-producing microbial electrolytic cell and a biological cathode domestication method thereof.

Background technique

With the development of the economy, people's demand for energy is increasing day by day, coal, oil, natural gas and other non-renewable energy can no longer meet people's growing needs, and the use of these non-renewable energy causes serious pollution to the environment. Therefore, vigorously developing renewable energy, taking the road of sustainable development, and satisfying the development of low-carbon economy are policies that must be followed. Hydrogen has become one of the most widely used energy carriers due to its clean, efficient, and renewable characteristics, and has attracted widespread attention at home and abroad. The current industrial hydrogen production methods are natural gas or tail gas separation hydrogen production and water electrolysis hydrogen production, but the cost is high and the energy consumption is relatively large. Traditional biological fermentation hydrogen production has the advantages of cleanliness, safety, and low energy consumption, but the utilization rate of raw materials is low. Microbial electrolysis cell is a bioenergy technology that uses renewable biomass to produce hydrogen developed on the basis of microbial fuel cells. Compared with traditional fermentation technology, microbial electrolysis cell technology overcomes the "fermentation bottleneck", and the energy conversion rate can reach more than 60%. While treating organic wastewater, it can realize the conversion between chemical energy, electrical energy and hydrogen energy.

The hydrogen production of the microbial electrolysis cell is the use of electricity-producing microorganisms to oxidize organic matter at the anode to generate electrons and protons. The electrons and protons are driven by an external voltage to catalyze the production of hydrogen at the cathode. In order to reduce the cathode overpotential and increase the cathode hydrogen production rate, platinum, palladium and other precious metals are commonly used as catalysts. However, the cost of these catalysts is relatively high, and long-term use is likely to cause catalyst poisoning and other shortcomings. Using microorganisms as catalysts can avoid the shortage of precious metals, improve the economics of microbial electrolytic cells, and lay a foundation for the practical application of microbial electrolytic cells.

Contents of the invention

According to one aspect of the present invention, there is provided a biocathode domestication method of a biocathode hydrogen-producing microbial electrolytic cell, characterized in that it comprises:

A) Culturing anodically electrogenic microbial populations in microbial fuel cell mode,

B) Domestication of anodic hydrogen-phagous microbial populations in the hydrogen production mode of microbial electrolysis cells,

C) Acclimatization and cultivation of cathodic hydrogen-producing microorganisms under the three-electrode mode.

According to a further aspect of the present invention, the bioanode obtained in the above step A) is combined with the domesticated and cultivated biocathode in the above step C) to form a biocathode type microbial electrolysis cell (400).

According to another aspect of the present invention, a kind of hydrogen production biocathode type microbial electrolysis cell is provided, it is characterized in that the hydrogen production biocathode type microbial electrolysis cell comprises:

the bioanode obtained in step A) above, and

Acclimate the cultured biocathode in step C) above.

According to a further aspect of the present invention, the above-mentioned microbial electrolytic cell is operated at room temperature with an applied voltage of 0.6-1.0V, and when the current density begins to drop, the solution in the microbial electrolytic cell is replaced with a new first solution to achieve microbial Electrolyzer biocathode catalyzes hydrogen production,

in

The components per liter of the first solution are: 1g sodium acetate, 0.31gNH ₄ Cl, 0.52gKCl, 13.44gNaHCO ₃ , 2.22gNaH ₂ PO ₄ 2H ₂ O, 9.20gNa ₂ HPO ₄ 12H ₂ O, 25mL nutrient salt Solution, 50 μL of vitamin solution, the rest is distilled water;

Wherein: the nutrient salt composition per liter is: 2.3gEDTA, 6.15gMgSO ₄ ·7H ₂ O, 0.5gMnSO ₄ ·H ₂ O, 1gNaCl, 0.1gFeSO ₄ ·7H ₂ O, 0.076gCaCl ₂ , 0.1gCoCl ₂ ·6H ₂ O, 0.13gZnCl ₂ , 0.01gCuSO ₄ ·5H ₂ O, 0.01gKAl(SO ₄ ) ₂ ·12H ₂ O, _{0.01gH 3} BO ₃ , 0.022g(NH ₄ ) 6Mo ₇ O ₂₄ ·4H ₂ O, 0.024 _{gNiCl2.6H2O , 0.025gNa2WO4.2H2O . _}

Description of drawings

Fig. 1 is a schematic diagram of the structure of a microbial fuel cell used in an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a microbial electrolysis cell for domesticating anodic hydrogen-phagic microbial populations according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a half-cell used for domesticating and culturing cathodic hydrogen-producing microorganisms in a three-electrode mode according to an embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a biocathode type microbial electrolysis cell for realizing hydrogen production by a biocathode type microbial electrolysis cell according to an embodiment of the present invention.

Figure 5 shows the relationship between the current density and the operating cycle of the microbial electrolytic cell under the condition of an applied voltage of 0.8V according to an embodiment of the present invention (wherein the current density is based on the solution volume).

FIG. 6 shows the relationship of the current density with time in the biocathode acclimation stage in the three-electrode mode half-cell according to an embodiment of the present invention.

Fig. 7 shows the results of cyclic voltammetry (CV) test of biocathode/blank carbon felt in one embodiment of the present invention.

Fig. 8 shows the results of the biocathode performance test in one embodiment of the present invention, that is, the relationship between current density/hydrogen production rate and the change of cathode electrode potential (wherein the current density is based on the solution volume).

detailed description

The biocathode domestication method of the biocathode type hydrogen-producing microbial electrolytic cell according to an embodiment of the present invention comprises the following steps:

A) Cultivate anodically electrogenic microbial populations in the microbial fuel cell mode (the structure of the microbial fuel cell is shown in the schematic diagram of Figure 1),

B) domestication of anodic hydrogen-phagic microbial populations in the hydrogen production mode of the microbial electrolytic cell (the structure of the microbial electrolytic cell is shown schematically in Figure 2),

C) Acclimate and cultivate cathodic hydrogen-producing microorganisms under the three-electrode mode (the schematic diagram of the structure is shown in Figure 3),

D) Combine the bioanode obtained in step A) with the domesticated and cultivated biocathode in step C) to form a biocathode microbial electrolytic cell, and operate the biocathode microbial electrolytic cell under an external voltage and room temperature environment.

Example 1: Cultivation of anode electrogenic microbial populations in microbial fuel cell mode

The structure of the microbial fuel cell (100) used is shown in the schematic diagram of FIG. 1 . Specific steps:

The first solution (see below for ingredients) was added to the microbial fuel cell (100). The anode of the microbial fuel cell (100) used carbon felt as the base material, and the cathode used acetylene black carbon film and brushed with 0.5mg-Pt/cm ² Catalyst, connect the external resistance R=1000Ω in the closed circuit system, run in batch mode, and continuously monitor the voltage at both ends of the external resistance R;

When the output voltage (the voltage across the external resistance R) of the microbial fuel cell (100) drops continuously and falls below 100mV in each operating cycle, replace the solution in the microbial fuel cell (100) with a fresh first solution, The replacement of the solution is repeated for several cycles until the maximum output voltage of the microbial fuel cell (100) is maintained at 500-600mV, and the start-up of the bioanode is completed.

The components per liter of the first solution are: 1g sodium acetate, 0.31gNH ₄ Cl, 0.52gKCl, 13.44gNaHCO ₃ , 2.22gNaH ₂ PO ₄ 2H ₂ O, 9.20gNa ₂ HPO ₄ 12H ₂ O, 25mL nutrient salt Solution, 50 μL of vitamin solution, the rest is distilled water;

Wherein: the nutrient salt composition per liter is: 2.3gEDTA, 6.15gMgSO ₄ ·7H ₂ O, 0.5gMnSO ₄ ·H ₂ O, 1gNaCl, 0.1gFeSO ₄ ·7H ₂ O, 0.076gCaCl ₂ , 0.1gCoCl ₂ ·6H ₂ O, 0.13gZnCl ₂ , 0.01gCuSO ₄ ·5H ₂ O, 0.01gKAl(SO ₄ ) ₂ ·12H ₂ O, _{0.01gH 3} BO ₃ , 0.022g(NH ₄ ) 6Mo ₇ O ₂₄ ·4H ₂ O, 0.024 _{gNiCl2 ·} 6H2O, _{0.025gNa2WO4 ·} 2H2O _;

Example 2: Domestication of anodic hydrogen phagocytic microbial populations under the hydrogen production mode of microbial electrolysis cells

The structure of the electrolytic cell adopted is schematically shown in FIG. 2 . Specific steps:

B1) Transfer the bioanode activated in step A to the microbial electrolysis cell (200) (Fig. 2) as the bioanode of the electrolysis cell (200). The cathode of the microbial electrolysis cell (200) uses carbon cloth as the basic material and supports 0.5 mg-Pt/cm ² of catalyst. After the first solution is added, a voltage of 0.6V is applied between the biological anode and the chemical cathode of the microbial electrolytic cell (200), and the batch operation is performed at room temperature, and the current intensity of the electrolytic cell (200) is continuously monitored. When the current density of the microbial electrolytic cell (200) dropped from a stable plateau to 100-200A/ ^m3 in each batch cycle, the solution in the microbial electrolytic cell (200) was replaced with a new first solution, and repeated The solution is replaced every cycle until the microbial electrolysis cell (200) starts to produce hydrogen. When the microbial electrolysis cell (200) can produce hydrogen stably for 10 cycles, gradually increase the voltage between the bioanode and the chemical cathode from 0.6V to 0.7V, 0.8V;

B2) Collect the gas produced by the microbial electrolytic cell (200) through the anaerobic bag; keep the gas collection anaerobic bag connected to the reactor microbial electrolytic cell (200) during the entire reaction cycle without exhausting;

B3) As shown in Figure 5, under the condition of an applied voltage of 0.8V, the current density of the electrolytic cell (200) continues to rise after 10 operating cycles, and when it runs to 40 cycles, the current density It reaches 500-600A/m ³ and tends to be stable. At this time, the cycle reaction time should be extended appropriately. When the current density of the microbial electrolytic cell (200) drops from the plateau current (500-600A/m ³ ) to 100-200A/m ³ , continue to apply 0.8V between the biological anode and the chemical cathode of the microbial electrolytic cell (200) The voltage makes the microbial electrolytic cell work in the low current area for 4-6 hours;

Fig. 5 shows the relationship between the current density and the operating cycle of the microbial electrolytic cell (200) in this embodiment under the condition of an applied voltage of 0.8V (the current density is based on the solution volume). B4) Repeat steps B2) and B3) for 15 batches to complete the domestication of hydrogen-phagocytic anode microorganisms;

Example 3: Acclimatization and cultivation of cathode hydrogen-producing microorganisms in the three-electrode mode

The structure of the adopted three-electrode mode half-cell is shown schematically in FIG. 3 . Specific steps:

C1) The bioanode in step B) is used as the cathode, and the acetylene black carbon film is used as the chemical anode to form a half-cell (300).

C2) Add the second solution (composition below) to the half-cell, keep the potential of the working electrode constant at -1.1V (relative to the saturated calomel electrode), pass hydrogen gas into one side of the chemical anode, and operate at room temperature. When the current density of the half-cell (300) drops below 80A/ ^m3 in each cycle, the solution in the half-cell (300) is replaced with a new second solution, and the solution replacement is repeated for a number of cycles until the half-cell (300) get a steady current. As shown in Figure 6, when the biocathode is in the half-cell (300) for the first 0-25 hours, the current density tends to decrease slowly. When the current drops below 80A/m ³ , replace the second solution of the half-cell (300), Continuously operate the half-cell (300), when the operation is about 180 hours, the current density reaches 100A/m ³ , the current density tends to be stable, and hydrogen production continues in this mode, that is, the domestication and cultivation of biocathode hydrogen-producing microorganisms are completed.

Figure 6 shows the relationship of the current density with time in the three-electrode mode half-cell of the embodiment 3 in the biocathode acclimation stage; wherein, the solid line represents the variation relationship of the biocathode, and the dotted line represents the blank cathode, that is, the blank carbon felt without biocatalyst Variation relationship; current density based on anion solution volume; arrows represent solution replacement.

The components per liter of the _second solution are: 0.31gNH4Cl, _0.52gKCl , _13.44gNaHCO3 , _{2.22gNaH2PO4 ·} 2H2O, _{9.20gNa2HPO4 · 12H2O} , 25mL nutrient salt solution, 50μL vitamin solution, the balance is distilled water;

Wherein: the nutrient salt composition per liter is: 2.3gEDTA, 6.15gMgSO ₄ ·7H ₂ O, 0.5gMnSO ₄ ·H ₂ O, 1gNaCl, 0.1gFeSO ₄ ·7H ₂ O, 0.076gCaCl ₂ , 0.1gCoCl ₂ ·6H ₂ O, 0.13gZnCl ₂ , 0.01gCuSO ₄ ·5H ₂ O, 0.01gKAl(SO ₄ ) ₂ ·12H ₂ O, _{0.01gH 3} BO ₃ , 0.022g(NH ₄ ) 6Mo ₇ O ₂₄ ·4H ₂ O, 0.024 _{gNiCl2 ·} 6H2O, _{0.025gNa2WO4 ·} 2H2O _;

FIG. 7 shows the results of cyclic voltammetry (CV) testing the biocathode/blank carbon felt of the half-cell (300) in this example. In Fig. 7, the solid points represent the test results of the biocathode, and the dots represent the test results of the blank cathode, that is, the blank carbon felt without biocatalyst; the sweep rate is 50mV/s, and the current density is based on the solution volume.

The biocathode and the blank carbon felt under the same conditions were tested by cyclic voltammetry (CV). The chemical double-layer area is significantly larger than the electrochemical double-layer area of the cathode of the blank carbon felt, and can generate a larger current density. It can be seen that the biocatalytic activity of the cathode microorganism is better, and the biocatalytic hydrogen production has occurred. Furthermore, from Figure 7, it can be concluded that the blank cathode (i.e. blank carbon felt without biocatalyst) by itself can generate a current density of 100A/ ^m3 when the potential is lower than -1.3V (vs. saturated calomel reference electrode) , hydrogen evolution can occur, so the electrode potential of the biocathode should be selected in the potential range to avoid the catalytic hydrogen evolution of the carbon felt itself.

Figure 8 shows the test results of the electrocatalytic performance of the biocathode in this example, that is, the relationship between the current density/hydrogen production rate and the potential change of the cathode electrode (wherein the current density is based on the solution volume).

As shown in Figure 8, the catalytic hydrogen production performance of the biocathode was characterized by controlling the cathode potential. As the cathode electrode potential decreased, the current density and hydrogen production rate of the biocathode (compared with the blank carbon felt) increased significantly. It shows that low cathode electrode potential is beneficial to biocatalytic hydrogen production, and the cathode electrode potential is in the range of -1.1 to -1.3V (relative to saturated calomel electrode), and the catalytic hydrogen production performance of biocathode is better.

Embodiment 4: Realize hydrogen production by biocathode type microbial electrolysis cell

The structure of the biocathode microbial electrolytic cell is shown schematically in Figure 4. Specific steps:

Combining the bioanode obtained in step A and the domesticated and cultivated biocathode in step C) to form a biocathode type microbial electrolysis cell (400), and operating the microbial electrolysis cell (400) at an external voltage of 0.6-1.0V and room temperature, When the current density begins to drop, replace the solution in the microbial electrolysis cell (400) with a new first solution to realize catalytic hydrogen production by the biological cathode of the microbial electrolysis cell (400), and the hydrogen production rate is shown in the following table:

Among them, the hydrogen production rate Q _H2 =V _H2 /(V _L T); V _H2 is the volume of hydrogen collected in the collection bag; V _L is the volume of the reactor solution in the biocathode type microbial electrolytic cell (400); T a cycle response time.

Claims (9)

1. produce a biological-cathode acclimation method for hydrogen microorganism electrolysis cell, it is characterized in that comprising:

A) under microbiological fuel cell pattern, anode electrogenesis microbial population is cultivated,

B) under microorganism electrolysis cell hydrogen-producing mode, tame anode and bite hydrogen microbial population,

C) under three electrode modes, domestication is cultivated negative electrode and is produced hydrogen microorganism,

Wherein

Described step B) comprising:

By steps A) in start biological anode be forwarded to microorganism electrolysis cell (200), as the biological anode of microorganism electrolysis cell (200), wherein said microorganism electrolysis cell (200) has chemical cathode,

After adding the first solution, between the biological anode and chemical cathode of microorganism electrolysis cell (200), apply 0.6V voltage, under room temperature environment, batch is run, and monitors the strength of current of electrolyzer (200) continuously,

Within each batch cycle, when microorganism electrolysis cell (200) current density starts from stable platform rapid drawdown to 100-200A/m ³time, change the solution in microorganism electrolysis cell (200) with the first fresh solution, repeat multiple cycle, until microorganism electrolysis cell (200) starts to produce hydrogen,

When microorganism electrolysis cell (200) can be stable product hydrogen 5-10 week after date, the impressed voltage of microorganism electrolysis cell (200) is progressively increased to 0.7V from 0.6V, 0.8V.

2. method according to claim 1, is characterized in that described steps A) comprising:

First solution is joined microbiological fuel cell (100), described microbiological fuel cell (100) comprises biological anode and chemical cathode,

In closed circuit system, access external resistance, batch is run, continuously the voltage at monitoring external resistance two ends,

When within each cycle of operation, when the output voltage of microbiological fuel cell (100) and the voltage at external resistance two ends constantly drop to lower than 100mV, the solution in microbiological fuel cell (100) is changed with the first fresh solution, repeat multiple cycle, until the maximum output voltage of microbiological fuel cell (100) can maintain 500 ~ 600mV, biological anode starts complete.

3. method according to claim 2, is characterized in that:

The described biological anode of microbiological fuel cell (100) adopts material based on carbon felt, and described chemical cathode adopts acetylene black carbon film and brushes 0.5mg-Pt/cm ²catalyzer.

4., according to the method for Claims 2 or 3, it is characterized in that:

Described first solution often rises component: 1g sodium acetate, 0.31gNH ₄cl, 0.52gKCl, 13.44gNaHCO ₃, 2.22gNaH ₂pO ₄2H ₂o, 9.20gNa ₂hPO ₄12H ₂o, 25mL nutrient salt solution, the vitamin solution of 50 μ L, surplus is distilled water;

Wherein: described nutritive salt often rises component and is: 2.3gEDTA, 6.15gMgSO ₄7H ₂o, 0.5gMnSO ₄h ₂o, 1gNaCl, 0.1gFeSO ₄7H ₂o, 0.076gCaCl ₂, 0.1gCoCl ₂6H ₂o, 0.13gZnCl ₂, 0.01gCuSO ₄5H ₂o, 0.01gKAl (SO ₄) ₂12H ₂o, 0.01gH ₃bO ₃, 0.022g (NH ₄) ₆mo ₇o ₂₄4H ₂o, 0.024gNiCl ₂6H ₂o, 0.025gNa ₂wO ₄2H ₂o.

5. method according to claim 1, is characterized in that described step B) comprise further:

B1) microorganism electrolysis cell (200) institute aerogenesis body is collected through anaerobism bag; Within whole reaction time, keep collecting anaerobism bag and being communicated with of microorganism electrolysis cell (200) of gas and be not vented;

B2) when under the impressed voltage of microorganism electrolysis cell (200) at 0.8V, current density drops to 100-200A/m from platform electric current ³time, continue the voltage applying 0.8V at microorganism electrolysis cell (200), make microorganism electrolysis cell (200) at low current district work 4-6 hour;

B3) repeating step B1) and B2) 10-20 batch, complete and bite the biological anode microbial acclimation of hydrogen;

Wherein, the chemical cathode of microorganism electrolysis cell (200) adopts material based on carbon cloth, load 0.5mg-Pt/cm ²catalyzer.

6. method according to claim 1, is characterized in that described step C) comprising:

C1) by step B) in biological anode be forwarded to half-cell (300), anode is chemical anode,

C2) in half-cell (300), add the second solution, by constant for working electrode potential relative to described reference electrode-1.1 ~-1.3V, chemical anode passes into hydrogen, runs half-cell (300) under room temperature environment,

When in each cycle, the current density of half-cell (300) drops to lower than 80A/m ³time, change the solution in half-cell (300) with the second fresh solution, repeat multiple cycle, until current density reaches 100A/m ³and tend towards stability, and continue in this mode to produce hydrogen, namely complete the domestication cultivation that biological-cathode produces hydrogen microorganism,

Described second solution often rises component: 0.31gNH ₄cl, 0.52gKCl, 13.44gNaHCO ₃, 2.22gNaH ₂pO ₄2H ₂o, 9.20gNa ₂hPO ₄12H ₂o, 25mL nutrient salt solution, the vitamin solution of 50 μ L, surplus is distilled water;

Wherein: described nutritive salt often rises component and is: 2.3gEDTA, 6.15gMgSO ₄7H ₂o, 0.5gMnSO ₄h ₂o, 1gNaCl, 0.1gFeSO ₄7H ₂o, 0.076gCaCl ₂, 0.1gCoCl ₂6H ₂o, 0.13gZnCl ₂, 0.01gCuSO ₄5H ₂o, 0.01gKAl (SO ₄) ₂12H ₂o, 0.01gH ₃bO ₃, 0.022g (NH ₄) ₆mo ₇o ₂₄4H ₂o, 0.024gNiCl ₂6H ₂o, 0.025gNa ₂wO ₄2H ₂o.

7. method according to claim 6, is characterized in that:

Described chemical anode is acetylene black carbon film and brushes 0.5mg-Pt/cm ²catalyzer, described reference electrode is saturated calomel electrode.

8. a biological-cathode type produces hydrogen microorganism electrolysis cell (400), it is characterized in that described biological-cathode type produces hydrogen microorganism electrolysis cell (400) and comprising:

Steps A as described in one of claim 1-7) in the biological anode that obtains, and

The step C that one of claim 1-7 is described) middle biological-cathode of taming cultivation.

9. biological-cathode type according to claim 8 produces hydrogen microorganism electrolysis cell (400), it is characterized in that:

Described microorganism electrolysis cell (400) is run under the impressed voltage and room temperature environment of 0.6-1.0V,

When the current density of microorganism electrolysis cell (400) starts to decline, change the solution in microorganism electrolysis cell (400) with the first fresh solution, realize microorganism electrolysis cell (400) biological-cathode catalyzing manufacturing of hydrogen,

Wherein

Described first solution often rises component: 1g sodium acetate, 0.31gNH ₄cl, 0.52gKCl, 13.44gNaHCO ₃, 2.22gNaH ₂pO ₄2H ₂o, 9.20gNa ₂hPO ₄12H ₂o, 25mL nutrient salt solution, the vitamin solution of 50 μ L, surplus is distilled water;

Wherein: described nutritive salt often rises component and is: 2.3gEDTA, 6.15gMgSO ₄7H ₂o, 0.5gMnSO ₄h ₂o, 1gNaCl, 0.1gFeSO ₄7H ₂o, 0.076gCaCl ₂, 0.1gCoCl ₂6H ₂o, 0.13gZnCl ₂, 0.01gCuSO ₄5H ₂o, 0.01gKAl (SO ₄) ₂12H ₂o, 0.01gH ₃bO ₃, 0.022g (NH ₄) ₆mo ₇o ₂₄4H ₂o, 0.024gNiCl ₂6H ₂o, 0.025gNa ₂wO ₄2H ₂o.