Microbial gel foam capable of suppressing explosion and inhibiting spontaneous combustion of coal and preparation method of microbial gel foam

Abstract

The invention belongs to the technical field of fire prevention and extinguishing of coal mine wells, and particularly relates to microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal and a preparation method of the microbial gel foam. The microbial agent is prepared from the following components in parts by mass: 1-2 parts of a gelling agent, 0.1-0.6 part of a cross-linking agent, 0.2-0.4 part of a surfactant, 1-3 parts of a microbial liquid and 94-97.9 parts of water, the microbial liquid is obtained by mixing a methane-oxidizing bacteria liquid and a CO-oxidizing bacteria liquid according to the volume ratio of 1: (0.5-2). The microbial gel foam provided by the invention not only has the advantages of strong flow diffusivity, oxygen isolation, cooling, excellent inhibition performance and the like of the gel foam, but also provides a favorable environment for growth and reproduction of microorganisms due to the high water locking property and the network structure of the microbial gel foam, and prolongs the survival activity of the microorganisms in a mine goaf; goaf combustible gas can be metabolized through microorganisms, CO2 is generated, the goaf environment is inerted, and comprehensive prevention and control of goaf coal spontaneous combustion and releasing or reducing of the combustible gas are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine fire prevention and extinguishing, and particularly relates to a microbial gel foam capable of suppressing explosion and inhibiting spontaneous combustion of coal and a preparation method thereof. Background Art

[0002] Mines are prone to spontaneous combustion of gas and coal, especially those with high gas content and high risk of spontaneous combustion, which pose a greater risk. Goafs are a prime location for this hazard. During the oxidation and spontaneous combustion of coal, combustible gases such as CH4, CO, and C2H4 are produced, causing the combustible system within the goaf to exhibit different combustion and explosion characteristics than those of CH4 alone. Furthermore, the presence of CO increases the risk of CH4 explosions, and this, combined with the greenhouse effect of CH4, has serious impacts on safe coal mining and the ecological environment. Therefore, preventing and controlling coal spontaneous combustion in mines while simultaneously eliminating combustible gases in the goaf is crucial for reducing the risk of combustible gas explosions caused by coal spontaneous combustion and ensuring safe mine production.

[0003] In recent years, microorganisms have become a new direction in coal spontaneous combustion prevention and fire extinguishing technology due to their low cost, strong reproductive capacity, and environmental friendliness. For example, patent publication number CN117286062A proposes using a bacterial solution of Pseudomonas putida as a microbial inhibitor to degrade active functional groups in the low-temperature oxidation stage of coal, slowing the coal-oxygen complexation reaction and reducing the coal's tendency to spontaneously combust. For example, patent publication number CN114961829A proposes injecting a mixture of aerobic and facultative anaerobic bacteria, as well as facultative anaerobic methane-oxidizing bacteria, into goafs to reduce oxygen concentrations and rapidly generate carbon dioxide, interrupting the coal spontaneous combustion reaction chain and preventing coal spontaneous combustion. However, in goafs with large caving spaces, complex air leakage environments, and increased combustible gas content, the bacterial solution is easily evaporated by heat over time and as the coal oxidizes and heats up, making it difficult to maintain long-term microbial growth, reproduction, and metabolism. Furthermore, the microbial solution is difficult to spread over a large area to cover the coal and inhibit the coal body, leading to the generation and accumulation of combustible gases in the goaf. Summary of the Invention

[0004] To address the above-mentioned issues, the present invention provides a microbial gel foam that suppresses explosions and retards coal spontaneous combustion, and its preparation method. The microbial gel foam provided by the present invention not only possesses the advantages of strong flow and diffusion, oxygen isolation and temperature reduction, and excellent retardant properties, but also has high water retention and a network structure that provides a favorable environment for microbial growth and reproduction, prolonging the survival and activity of microorganisms in mine goafs. Furthermore, the microorganisms metabolize combustible gases in the goaf and generate CO2 to inert the goaf environment, ultimately achieving comprehensive prevention and control of coal spontaneous combustion in the goaf and eliminating or reducing combustible gases.

[0005] The present invention solves the above technical problems through the following technical solutions.

[0006] One of the purposes of the present invention is to provide a microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal, which is prepared from the following components in parts by mass: 1 to 2 parts of a gelling agent, 0.1 to 0.6 parts of a cross-linking agent, 0.2 to 0.4 parts of a surfactant, 1 to 3 parts of a microbial liquid, and 94 to 97.9 parts of water; the microbial liquid is obtained by mixing a methane oxidizing bacteria liquid and a CO oxidizing bacteria liquid in a volume ratio of 1:0.5 to 1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

[0007] Furthermore, the method for preparing the methane oxidizing bacteria liquid comprises the following steps: The methane oxidizing bacteria are inoculated into a methane oxidizing bacteria culture medium using CH4 gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a methane oxidizing bacteria liquid.

[0008] Furthermore, the volume concentration of CH4 gas in the culture medium is 10% to 20%, and the volume ratio of methane oxidizing bacteria to the culture medium is 1:2 to 9.

[0009] Furthermore, a methanotrophic bacteria culture medium was prepared according to the following components: 0.70 g to 0.72 g of Na2HPO4·12H2O, 0.27 g to 0.28 g of KH2PO4, 1 g to 1.2 g of MgSO4·7H2O, 1 g to 1.2 g of KNO3, 0.1 g to 0.2 g of CaCl2·6H2O, 0.20 g to 0.30 g of FeCl3, 0.20 g to 0.30 g of NH4Cl and 0.694 g to 1.058 g of trace elements, 1 L of water, pH 7; trace elements were added at 0.15 g to 0.05 g. 0.25g of FeSO4·7H2O, 0.02g~0.04g of CuSO4·7H2O, 0.002g~0.004g of Na2MoO4·2H2O, 0.01g~0.02g of ZnSO4·7H2O, 0.002g~0.004g of MnSO4·H2O, 0.4g~0.6g of Na2EDTA, 0.04g~0.05g of CoCl2·6H2O, 0.06g~0.07g of H3BO3 and 0.01g~0.02g of NiCl2·6H2O are mixed.

[0010] Furthermore, the method for preparing the CO oxidizing bacteria liquid comprises the following steps: The CO oxidizing bacteria are inoculated into a CO oxidizing bacteria culture medium using CO gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a CO oxidizing bacteria solution.

[0011] Furthermore, the volume concentration of CO gas in the CO culture medium is 10% to 20%, and the volume ratio of CO oxidizing bacteria to the culture medium is 1:2 to 9.

[0012] Furthermore, a CO oxidizing bacteria culture medium is prepared according to the following components: 4.0 g to 5.0 g of Na2HPO4·12H2O, 0.7 g to 0.8 g of KH2PO4, 0.15 g to 0.25 g of MgSO4·7H2O, 1.0 g to 2.0 g of NH4Cl, 0.02 g to 0.04 g of CaCl2·6H2O and 0.46 g to 1.03 g of trace elements, 1 L of water, pH 7; trace elements It is obtained by mixing 0.1g~0.2g of ZnSO4·7H2O, 0.2g~0.4g of H3BO3, 0.02g~0.04g of Na2MoO4·2H2O, 0.01g~0.02g of CuCl2·2H2O, 0.02g~0.04g of MnCl2·4H2O, 0.1g~0.3g of CoCl2·6H2O and 0.01g~0.03g of NiCl2·6H2O.

[0013] Furthermore, the gelling agent is at least one of sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and polyvinyl alcohol; the cross-linking agent is at least one of calcium chloride, calcium L-lactate, aluminum citrate, and sodium tetraborate; and the surfactant is at least one of sodium lauryl sulfate, sodium lauroyl glutamate, cocamidopropyl betaine, dodecyl betaine, tea saponin, and alkyl glycoside.

[0014] A second object of the present invention is to provide a method for preparing the above-mentioned explosion-suppressing and coal spontaneous combustion-retarding microbial gel foam, comprising the following steps: S1. Weigh the following according to mass: 1 to 2 parts of gelling agent, 0.1 to 0.6 parts of cross-linking agent, 0.2 to 0.4 parts of surfactant, 1 to 3 parts of microbial liquid, and 94 to 97.9 parts of water.

[0015] S2. Divide the water into three parts, dissolve the surfactant in the water to obtain a foam precursor; dissolve the gelling agent in the water to obtain a gel matrix solution; and dissolve the crosslinking agent in the water to obtain a crosslinking agent solution.

[0016] S2. Mix the gel matrix solution and the foam precursor, and foam the mixed solution using the Waring-Blender method. After the gel foam matrix is ​​formed, divide the microbial liquid into three equal parts, wherein two parts of the microbial liquid are added to the gel foam matrix, and after uniform dispersion, the cross-linker solution is added under stirring, and after uniform stirring, the microbial gel foam matrix is ​​obtained, and then the other part of the microbial liquid is evenly sprayed onto the surface of the microbial gel foam matrix, so that the inside and outer surface of the gel foam matrix are loaded with microorganisms, and finally the microbial gel foam is obtained.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal provided by the present invention uses a gelling agent, a cross-linking agent and a surfactant to form a gel foam matrix with a high water-locking network structure, and then uses the gel foam matrix as a carrier to load methane oxidizing bacteria. Methylobacter and CO oxidizing bacteria Comamonas On the one hand, the gel foam matrix provides a reproductive and metabolic environment for methane-oxidizing and CO-oxidizing bacteria, as well as the necessary water and nutrient solution, creating a favorable growth environment for the microorganisms. Methane-oxidizing and CO-oxidizing bacteria use combustible gases as a carbon source to maintain their self-reproduction and metabolism, extending the microbial survival activity in the mine goaf. Furthermore, the self-reproduction and metabolism process can eliminate or reduce combustible gases in the goaf, while consuming O₂ to produce large amounts of CO₂ gas, inerting the goaf environment. On the other hand, the gel foam matrix has the advantages of strong flow and diffusion, strong accumulation, and good stability. It primarily inhibits the coal body through physical pathways such as oxygen isolation, cooling, and sealing. Therefore, the microbial gel foam has the dual function of preventing spontaneous combustion of coal in the goaf and eliminating combustible gases. It fundamentally suppresses the accumulation of combustible gases in the goaf, avoiding gas explosion accidents caused by excessive combustible gases, and ultimately achieving comprehensive prevention and control of spontaneous combustion of coal in the goaf and elimination of combustible gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram of gaseous metabolic products of microorganisms in Example 3 of the present invention.

[0019] Figure 2 This is a diagram of gaseous metabolites of microorganisms in Comparative Example 1 of the present invention.

[0020] Figure 3 This is a diagram of gaseous metabolites of microorganisms in Comparative Example 1 of the present invention.

[0021] Figure 4 Figure 2 shows the CO production of pure coal samples and coal samples treated with microbial gel foam as a function of temperature. DETAILED DESCRIPTION

[0022] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods.

[0024] Existing technology prevents spontaneous combustion by injecting microorganisms into goafs, where they degrade coal through low-temperature oxidation or by reducing oxygen concentration in the goaf and rapidly generating carbon dioxide, thereby interrupting the coal's spontaneous combustion reaction chain. However, in goafs with large caving spaces, complex air leakage, and increased levels of combustible gases, the bacterial solution is easily evaporated over time as the coal oxidizes and heats up, making it difficult to sustain long-term microbial growth, reproduction, and metabolism. Furthermore, the microbial solution struggles to spread widely enough to cover the coal and inhibit its degradation, leading to spontaneous combustion of the coal in the goaf and the accumulation of combustible gases.

[0025] Based on the above problems, the present invention provides a microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal, which is prepared from the following components in parts by mass: 1 to 2 parts of gelling agent, 0.1 to 0.6 parts of cross-linking agent, 0.2 to 0.4 parts of surfactant, 1 to 3 parts of microbial liquid, and 94 to 97.9 parts of water; the microbial liquid is obtained by mixing methane oxidizing bacteria liquid and CO oxidizing bacteria liquid in a volume ratio of 1:0.5 to 1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

[0026] It should be noted that the methane oxidizing bacteria provided by the present invention are extracted from the mine environment, so the microorganisms are able to adapt to the complex environment of the mine goaf and reproduce and metabolize. Methylobacter and CO oxidizing bacteria ComamonasAll of these are disclosed in Deng Y, Wang CP, Guan XJ, Chen WL, Deng J, Xiao Y, ZhangY, He Y J. Microbial co-cultivation: Reaction dynamics of combustible gasesbioremediation in goaf[J]. Process Safety and Environmental Protection, 2024,190: 517-528. The applicant promises to make the biological material available to the public within 20 years.

[0027] The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal provided by the present invention uses a gelling agent, a cross-linking agent and a surfactant to form a gel foam matrix with a high water-locking network structure, and then uses the gel foam matrix as a carrier to load methane oxidizing bacteria. Methylobacter and CO oxidizing bacteria Comamonas On the one hand, the gel foam matrix provides a reproductive and metabolic environment for methane-oxidizing and CO-oxidizing bacteria, as well as the necessary water and nutrient solution, creating a favorable growth environment for the microorganisms. Methane-oxidizing and CO-oxidizing bacteria use combustible gases as a carbon source to maintain their self-reproduction and metabolism, extending the microbial survival activity in the mine goaf. Furthermore, the self-reproduction and metabolism process can eliminate or reduce combustible gases in the goaf, while consuming O₂ to produce large amounts of CO₂ gas, inerting the goaf environment. On the other hand, the gel foam matrix has the advantages of strong flow and diffusion, strong accumulation, and good stability. It primarily inhibits the coal body through physical pathways such as oxygen isolation, cooling, and sealing. Therefore, the microbial gel foam has the dual function of preventing spontaneous combustion of coal in the goaf and eliminating combustible gases. It fundamentally suppresses the accumulation of combustible gases in the goaf, avoiding gas explosion accidents caused by excessive combustible gases, and ultimately achieving comprehensive prevention and control of spontaneous combustion of coal in the goaf and elimination of combustible gases.

[0028] In some embodiments, the method for preparing the methane oxidizing bacteria liquid comprises the following steps: The methanotrophic bacteria seed liquid is inoculated into a methanotrophic bacteria culture medium using CH4 gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a methanotrophic bacteria liquid.

[0029] It should be noted that after the methane oxidizing bacteria solution was cultured at room temperature for 5 to 7 days, the OD of the methane oxidizing bacteria in the logarithmic phase and the stable period was 600 The maximum is 0.45.

[0030] In a specific embodiment, the volume concentration of CH4 gas in the culture medium is 10% to 20%, and the volume ratio of the methanotrophic bacteria seed solution to the culture medium is 1:2 to 9. As a preferred embodiment of the present invention, the volume ratio of the methanotrophic bacteria seed solution to the culture medium is 1:9, 2:8, or 3:7.

[0031] It should be noted that the present invention cultivates methane-oxidizing bacteria in a methane-oxidizing bacteria culture medium using CH4 gas as the sole carbon source, which can obtain a bacterial solution with high activity in a shorter period of time, form a stable bacterial community structure, and improve the loading capacity and tolerance of the gel foam matrix.

[0032] In some embodiments, the methanotrophic bacteria culture medium is prepared according to the following components: 0.70g to 0.72g of Na2HPO4·12H2O, 0.27g to 0.28g of KH2PO4, 1g to 1.2g of MgSO4·7H2O, 1g to 1.2g of KNO3, 0.1g to 0.2g of CaCl2·6H2O, 0.20g to 0.30g of FeCl3, 0.20g to 0.30g of NH4Cl and 0.694g to 1.058g of trace elements, 1L of water, pH 7; the trace elements are 0.15g The obtained product is obtained by mixing 0.02g~0.25g of FeSO4·7H2O, 0.02g~0.04g of CuSO4·7H2O, 0.002g~0.004g of Na2MoO4·2H2O, 0.01g~0.02g of ZnSO4·7H2O, 0.002g~0.004g of MnSO4·H2O, 0.4g~0.6g of Na2EDTA, 0.04g~0.05g of CoCl2·6H2O, 0.06g~0.07g of H3BO3 and 0.01g~0.02g of NiCl2·6H2O.

[0033] The method for preparing a methane-oxidizing bacteria seed solution comprises the following steps: in a sterile environment, using a sterilized bamboo stick to pick a single colony of methane-oxidizing bacteria and inoculate it into a sterilized liquid culture bottle, then using a syringe to replace 10% to 20% of CH4 gas into the culture bottle, and sealing the bottle, placing it in a shaking incubator at 30°C and a rotation speed of 180 r / min for cultivation, and continuously cultivating for 3 to 5 generations, and taking the culture solution of the methane-oxidizing bacteria in the logarithmic phase to prepare the methane-oxidizing bacteria seed solution.

[0034] In some embodiments, the method for preparing the CO oxidizing bacteria liquid comprises the following steps: The CO oxidizing bacteria seed liquid is inoculated into a CO oxidizing bacteria culture medium using CO gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a CO oxidizing bacteria liquid.

[0035] It should be noted that after the CO oxidizing bacteria solution was cultured at room temperature for 5 to 7 days, the OD of the CO oxidizing bacteria in the logarithmic phase and the stable period was 600 The maximum value can reach 0.32.

[0036] In some embodiments, the volume concentration of CO gas in the CO culture medium is 10% to 20%, and the volume ratio of the CO oxidizing bacteria seed solution to the culture medium is 1:2 to 9. As a preferred embodiment of the present invention, the volume ratio of the CO oxidizing bacteria seed solution to the culture medium is 1:9, 2:8, or 3:7.

[0037] It should be noted that the CO oxidizing bacteria culture medium of the present invention uses CO gas as the sole carbon source to culture CO oxidizing bacteria, which can obtain a highly active bacterial liquid in a relatively short period of time, form a stable bacterial community structure, and thus improve the survival activity of the bacterial community in the gel foam matrix.

[0038] In some embodiments, the CO oxidizing bacteria culture medium is prepared according to the following components: 4.0 g to 5.0 g of Na2HPO4·12H2O, 0.7 g to 0.8 g of KH2PO4, 0.15 g to 0.25 g of MgSO4·7H2O, 1.0 g to 2.0 g of NH4Cl, 0.02 g to 0.04 g of CaCl2·6H2O and 0.46 g to 1.03 g of trace elements, 1 L of water, pH 7; trace elements The elements are obtained by mixing 0.1g~0.2g of ZnSO4·7H2O, 0.2g~0.4g of H3BO3, 0.02g~0.04g of Na2MoO4·2H2O, 0.01g~0.02g of CuCl2·2H2O, 0.02g~0.04g of MnCl2·4H2O, 0.1g~0.3g of CoCl2·6H2O and 0.01g~0.03g of NiCl2·6H2O.

[0039] The method for preparing a seed solution of CO oxidizing bacteria comprises the following steps: in a sterile environment, using a sterilized bamboo stick to pick a single colony of CO oxidizing bacteria and inoculate it into a sterilized liquid culture bottle, then using a syringe to replace 10% to 20% of CO gas into the culture bottle, and sealing the bottle. The bottle is then placed in a shaking incubator at 30°C and a rotation speed of 180 r / min for cultivation, and the culture is continuously cultivated for 3 to 5 generations. The culture solution of the methane oxidizing bacteria in the logarithmic phase is used to prepare the seed solution of CO oxidizing bacteria.

[0040] In some embodiments, the gelling agent is at least one of sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and polyvinyl alcohol; the crosslinking agent is at least one of calcium chloride, calcium L-lactate, aluminum citrate, and sodium tetraborate; and the surfactant is at least one of sodium lauryl sulfate, sodium lauroyl glutamate, cocamidopropyl betaine, lauryl betaine, tea saponin, and alkyl glycoside. It should be noted that the microbial gel foam components prepared by the present invention are widely available, environmentally friendly, non-toxic, inexpensive, and simple to prepare. They have promising application prospects in coal mines and are worthy of widespread promotion.

[0041] In some embodiments, the microbial gel foam further contains gluconic acid for adjusting pH. -lactone, controls the release rate of cross-linking ions, thereby controlling the gelling time of the gel foam.

[0042] In addition, the present invention also provides a method for preparing the above-mentioned explosion-suppressing and coal spontaneous combustion-retarding microbial gel foam, comprising the following steps: S1. Weigh the following according to mass: 1-2 parts of gelling agent, 0.1-0.6 parts of cross-linking agent, 0.2-0.4 parts of surfactant, 1-3 parts of microbial culture liquid, and 94-97.9 parts of water.

[0043] S2. Divide the water into three parts, dissolve the gelling agent in the first part of water to obtain a gel matrix solution; dissolve the surfactant in the second part of water to obtain a foam precursor; and dissolve the crosslinking agent in the third part of water to obtain a crosslinking agent solution.

[0044] S3. Mix the gel matrix solution and the foam precursor, and foam the mixed solution using the Waring-Blender method. After the gel foam matrix is ​​formed, divide the microbial liquid into three equal parts, wherein two parts of the microbial liquid are added to the gel foam matrix, and after uniform dispersion, the cross-linker solution is added under stirring, and after uniform stirring, the microbial gel foam matrix is ​​obtained, and then the other part of the microbial liquid is evenly sprayed onto the surface of the microbial gel foam matrix, so that the inside and outer surface of the gel foam matrix are loaded with microorganisms, and finally the microbial gel foam is obtained.

[0045] The following is further described through specific examples.

[0046] Example 1 A microbial gel foam for suppressing explosion and inhibiting coal spontaneous combustion is prepared from the following components in parts by mass: 1 part of sodium alginate, 0.1 part of calcium L-lactate, 0.2 part of sodium lauroyl glutamate, 3 parts of microbial culture liquid and 95.7 parts of deionized water; the microbial culture liquid is obtained by mixing methane oxidizing bacteria liquid and CO oxidizing bacteria liquid in a volume ratio of 1:1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria areComamonas .

[0047] The preparation method of the above-mentioned microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1 part of sodium alginate and fully dissolve it in 49 parts of deionized water. Then stir at 60° C. and 3000 r / min until no obvious flocculent material is left in the solution, thereby obtaining a sodium alginate solution.

[0048] Preparation of foam precursor: Weigh 0.2 parts of sodium lauroyl glutamate, dissolve it in 39.8 parts of deionized water, and mix them evenly at room temperature to obtain a sodium lauroyl glutamate solution.

[0049] Preparation of the crosslinking agent: Weigh 0.1 parts of L-calcium lactate, dissolve it in 6.9 parts of deionized water, and stir at room temperature and a stirring speed of 1500 r / min until no visible particles or precipitation are left in the solution to obtain a L-calcium lactate solution.

[0050] S2. Cultivation of microbial culture: inoculate the methanotrophic bacteria seed liquid into the methanotrophic bacteria culture medium, wherein the methanotrophic bacteria culture medium uses CH4 gas with a volume concentration of 10% as the sole carbon source, and uniformly mix the methanotrophic bacteria seed liquid and the methanotrophic bacteria culture medium in a volume ratio of 2:8, and culture at room temperature for 7 days to obtain the methanotrophic bacteria culture medium; wherein the methanotrophic bacteria culture medium is prepared according to the following components: 0.717g Na2HPO4·12H2O, 0.272g KH2PO4, 1g MgSO4·7H2O, 1g KNO3, 0.1g CaCl2·6H2O, 0.25g FeCl3, 0.25g NH4Cl and 0.866g trace elements, 1L water, pH 7; trace elements are obtained by mixing 0.2g FeSO4·7H2O, 0.03g CuSO4·7H2O, 0.003g Na2MoO4·2H2O, 0.01g ZnSO4·7H2O, 0.003g MnSO4·H2O, 0.5g Na2EDTA, 0.048g CoCl2·6H2O, 0.062g / L H3BO3 and 0.01g NiCl2·6H2O.

[0051] The CO2 oxidizing bacteria seed liquid was inoculated into the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium used CO gas with a volume concentration of 10% as the sole carbon source. The CO2 oxidizing bacteria seed liquid and the methane oxidizing bacteria culture medium were evenly mixed in a volume ratio of 2:8 and cultured at room temperature for 7 days to obtain the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium was prepared according to the following components: 4.5g of Na2HPO4·12H2O, 0.75g of KH2PO4, 0.2g of MgSO4·7H2O, 1 0.5g of NH4Cl, 0.03g of CaCl2·6H2O and 0.69g of trace elements, 1L of water, pH value 7, trace elements are obtained by mixing 0.1g of ZnSO4·7H2O, 0.3g of H3BO3, 0.03g of Na2MoO4·2H2O, 0.01g of CuCl2·2H2O, 0.03g of MnCl2·4H2O, 0.2g of CoCl2·6H2O and 0.02g of NiCl2·6H2O.

[0052] The methane oxidizing bacteria liquid and the CO oxidizing bacteria liquid were mixed at a volume ratio of 1:1 to obtain a microbial liquid.

[0053] S3. Preparation of microbial gel foam: The sodium lauroyl glutamate solution and the sodium alginate matrix solution are added into a mechanical stirrer, stirred and foamed at a stirring speed of 3000 r / min, and a gel foam matrix solution is obtained after the liquid level is highly stable; the microbial culture liquid is divided into three equal parts, 2 parts of the microbial culture liquid are added to the gel foam matrix solution, and after stirring and mixing, the L-calcium lactate solution is slowly added dropwise at a uniform speed under stirring, and after mixing evenly, a microbial gel foam matrix is ​​obtained; finally, 1 part of the microbial culture liquid is sprayed on the outside of the microbial gel foam matrix, so that the inside and the outer surface of the gel foam structure are loaded with microorganisms to obtain a microbial gel foam.

[0054] Example 2 A microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal is prepared from the following components in parts by mass: 1 part of sodium carboxymethyl cellulose, 0.6 part of aluminum citrate, gluconic acid- -lactone (GDL) 1 part, cocamidopropyl betaine 0.4 parts and deionized water 94 parts; microbial culture is obtained by mixing methane oxidizing bacteria culture and CO oxidizing bacteria culture in a volume ratio of 1:1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

[0055] The preparation method of the microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1 part of sodium carboxymethyl cellulose and fully dissolve it in 49 parts of deionized water. Then stir at 45° C. and 3000 r / min until the solution is free of flocculent matter, thereby obtaining a sodium carboxymethyl cellulose gel matrix solution.

[0056] Preparation of foam precursor: Weigh 0.4 parts of cocamidopropyl betaine, dissolve it in 39.6 parts of deionized water, and mix well at room temperature to obtain a cocamidopropyl betaine solution.

[0057] Preparation of the cross-linking agent: 0.6 parts of aluminum citrate was weighed and dissolved in 5.4 parts of deionized water, and then stirred at room temperature and a stirring speed of 1500 r / min for 10 minutes to obtain an aluminum citrate solution.

[0058] S2. Cultivation of microbial culture: A methanotrophic bacteria seed solution was inoculated into a methanotrophic bacteria culture medium containing 10% CH4 gas by volume as the sole carbon source. The methanotrophic bacteria seed solution and the methanotrophic bacteria culture medium were uniformly mixed in a volume ratio of 2:8, and cultured at room temperature for 7 days to obtain a methanotrophic bacteria culture medium. The methanotrophic bacteria culture medium was prepared according to the following components: 0.717 g of Na2HPO4·12H2O, 0.272 g of KH2PO4, 1 g of MgSO4·7H2O, 1 g of KNO3, and 0.1 g of CaCl2·6H2O. , 0.25g FeCl3, 0.25g NH4Cl and 0.866g trace elements, 1L water, pH value is 7; trace elements are obtained by mixing 0.2g FeSO4·7H2O, 0.03g CuSO4·7H2O, 0.003g Na2MoO4·2H2O, 0.01g ZnSO4·7H2O, 0.003g MnSO4·H2O, 0.5g Na2EDTA, 0.048g CoCl2·6H2O, 0.062g / L H3BO3 and 0.01g NiCl2·6H2O.

[0059] The CO2 oxidizing bacteria seed liquid was inoculated into the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium used CO gas with a volume concentration of 10% as the sole carbon source. The CO2 oxidizing bacteria seed liquid and the methane oxidizing bacteria culture medium were evenly mixed in a volume ratio of 2:8 and cultured at room temperature for 7 days to obtain the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium was prepared according to the following components: 4.5g of Na2HPO4·12H2O, 0.75g of KH2PO4, 0.2g of MgSO4·7H2O, 1 0.5g of NH4Cl, 0.03g of CaCl2·6H2O and 0.69g of trace elements, 1L of water, pH value 7, trace elements are obtained by mixing 0.1g of ZnSO4·7H2O, 0.3g of H3BO3, 0.03g of Na2MoO4·2H2O, 0.01g of CuCl2·2H2O, 0.03g of MnCl2·4H2O, 0.2g of CoCl2·6H2O and 0.02g of NiCl2·6H2O.

[0060] The methane oxidizing bacteria liquid and the CO oxidizing bacteria liquid were mixed at a volume ratio of 1:1 to obtain a microbial liquid.

[0061] S3. Preparation of microbial gel foam: The sodium carboxymethylcellulose gel matrix solution and the cocamidopropyl betaine solution were added into a mechanical stirrer and stirred at a stirring speed of 3000 r / min to foam. After the liquid level was stabilized, a gel foam matrix solution was obtained. The microbial culture liquid was divided into three equal parts, and 2 parts of the microbial culture liquid were added to the gel foam matrix solution. After stirring and mixing, the aluminum citrate solution was slowly added dropwise at a uniform speed under stirring, and 1 part of gluconic acid- -lactone (GDL), mixed evenly to obtain a microbial gel foam matrix, and finally sprayed 1 part of microbial liquid on the outside of the microbial gel foam matrix, so that the inside and outside surfaces of the gel foam structure are loaded with microorganisms, and finally a microbial gel foam is obtained.

[0062] Example 3 A microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal is prepared from the following components in parts by mass: 1.2 parts of sodium alginate, 0.12 parts of calcium L-lactate, 0.2 parts of alkyl glycoside, 0.1 parts of tea saponin, 3 parts of a mixed bacterial solution of methane oxidizing bacteria and CO oxidizing bacteria, and 95.38 parts of deionized water; the microbial solution is obtained by mixing the methane oxidizing bacteria solution and the CO oxidizing bacteria solution in a volume ratio of 1:1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

[0063] The preparation method of the above-mentioned microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1.2 parts of sodium alginate and fully dissolve it in 48.8 parts of deionized water. Then stir at 60° C. and 3000 r / min until no obvious flocculent material remains in the solution, thereby obtaining a sodium alginate solution.

[0064] Preparation of foam precursor: Weigh 0.2 parts of alkyl glycoside and 0.1 parts of tea saponin, dissolve them in 39.7 parts of deionized water, and mix them evenly at room temperature to obtain a composite foam precursor.

[0065] Preparation of the crosslinking agent: Weigh 0.12 parts of L-calcium lactate, dissolve it in 6.88 parts of deionized water, and stir at room temperature and a stirring speed of 1500 r / min until no visible particles or precipitation are left in the solution to obtain a L-calcium lactate solution.

[0066] S2. Cultivation of microbial culture: A methanotrophic bacteria seed solution was inoculated into a methanotrophic bacteria culture medium containing 10% by volume CH4 gas as the sole carbon source. The methanotrophic bacteria seed solution and the methanotrophic bacteria culture medium were uniformly mixed in a volume ratio of 2:8, and cultured at room temperature for 7 days to obtain a methanotrophic bacteria culture medium. The methanotrophic bacteria culture medium was prepared according to the following components: 0.717 g of Na2HPO4·12H2O, 0.272 g of KH2PO4, 1 g of MgSO4·7H2O, 1 g of KNO3, and 0.1 g of CaCl2·6H2O. , 0.25g FeCl3, 0.25g NH4Cl and 0.866g trace elements, 1L water, pH value is 7; trace elements are obtained by mixing 0.2g FeSO4·7H2O, 0.03g CuSO4·7H2O, 0.003g Na2MoO4·2H2O, 0.01g ZnSO4·7H2O, 0.003g MnSO4·H2O, 0.5g Na2EDTA, 0.048g CoCl2·6H2O, 0.062g / L H3BO3 and 0.01g NiCl2·6H2O.

[0067] The CO2 oxidizing bacteria seed liquid was inoculated into the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium used CO gas with a volume concentration of 10% as the sole carbon source. The CO2 oxidizing bacteria seed liquid and the methane oxidizing bacteria culture medium were evenly mixed in a volume ratio of 2:8 and cultured at room temperature for 7 days to obtain the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium was prepared according to the following components: 4.5g of Na2HPO4·12H2O, 0.75g of KH2PO4, 0.2g of MgSO4·7H2O, 1 0.5g of NH4Cl, 0.03g of CaCl2·6H2O and 0.69g of trace elements, 1L of water, pH value 7, trace elements are obtained by mixing 0.1g of ZnSO4·7H2O, 0.3g of H3BO3, 0.03g of Na2MoO4·2H2O, 0.01g of CuCl2·2H2O, 0.03g of MnCl2·4H2O, 0.2g of CoCl2·6H2O and 0.02g of NiCl2·6H2O.

[0068] The methane oxidizing bacteria liquid and the CO oxidizing bacteria liquid were mixed at a volume ratio of 1:1 to obtain a microbial liquid.

[0069] S3. Preparation of microbial gel foam: Sodium alginate solution and compound foam precursor are added into a mechanical stirrer, stirred and foamed at a stirring speed of 3000 r / min, and a gel foam matrix solution is obtained after the liquid level is highly stable; the microbial culture liquid is divided into three equal parts, 2 parts of microbial culture liquid are added to the gel foam matrix solution, and after stirring and mixing, L-calcium lactate solution is slowly added dropwise at a uniform speed under stirring, and mixed evenly to obtain a microbial gel foam matrix; finally, 1 part of microbial culture liquid is sprayed on the outside of the microbial gel foam matrix, so that the inside and outer surface of the gel foam structure are loaded with microorganisms, and finally a microbial gel foam is obtained.

[0070] Comparative Example 1 A microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal is prepared from the following components by weight: 1.2 parts of sodium alginate, 0.12 parts of calcium L-lactate, 0.2 parts of alkyl glycoside, 0.1 parts of tea saponin, 3 parts of methane oxidizing bacteria liquid and 95.58 parts of deionized water; wherein the methane oxidizing bacteria is Methylobacter.

[0071] The preparation method of the microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1.2 parts of sodium alginate and dissolve it in 48.8 parts of deionized water. Then stir at 60° C. and 3000 rpm until no obvious flocculent material remains in the solution, thereby obtaining a sodium alginate solution.

[0072] Preparation of foam precursor: Weigh 0.2 parts of alkyl glycoside and 0.1 parts of tea saponin, dissolve them in 39.7 parts of deionized water, and mix them evenly at room temperature to obtain a composite foam precursor.

[0073] Preparation of the crosslinking agent: Weigh 0.12 parts of L-calcium lactate, dissolve it in 6.88 parts of deionized water, and stir at room temperature and a stirring speed of 1500 r / min until no visible particles or precipitation are left in the solution to obtain a L-calcium lactate solution.

[0074] S2. Cultivation of methane-oxidizing bacteria liquid: inoculate the methane-oxidizing bacteria seed liquid into the methane-oxidizing bacteria culture medium, wherein the methane-oxidizing bacteria culture medium uses CH4 gas with a volume concentration of 10% as the sole carbon source, and uniformly mix the methane-oxidizing bacteria seed liquid and the methane-oxidizing bacteria culture medium in a volume ratio of 2:8. Cultivate at room temperature for 7 days to obtain the methane-oxidizing bacteria liquid; wherein the methane-oxidizing bacteria culture medium is prepared according to the following components: 0.717g Na2HPO4·12H2O, 0.272g KH2PO4, 1g MgSO4·7H2O, 1g KNO3, 0.1g CaCl2·6H2 O, 0.25g FeCl3, 0.25g NH4Cl and 0.866g trace elements, 1L water, pH 7; trace elements are obtained by mixing 0.2g FeSO4·7H2O, 0.03g CuSO4·7H2O, 0.003g Na2MoO4·2H2O, 0.01g ZnSO4·7H2O, 0.003g MnSO4·H2O, 0.5g Na2EDTA, 0.048g CoCl2·6H2O, 0.062g / L H3BO3 and 0.01g NiCl2·6H2O.

[0075] S3. Preparation of microbial gel foam: A sodium alginate matrix solution and a compound foam precursor are added to a mechanical stirrer, stirred and foamed at a stirring speed of 3000 r / min, and a gel foam matrix solution is obtained after the liquid level is stabilized; the methane oxidizing bacteria liquid is divided into three equal parts, 2 parts of the methane oxidizing bacteria liquid are added to the gel foam matrix solution, and after stirring and mixing, L-calcium lactate solution is slowly added dropwise at a uniform speed under stirring, and after mixing evenly, a microbial gel foam matrix is ​​obtained; finally, 1 part of the methane oxidizing bacteria liquid is sprayed on the outer surface of the microbial gel foam matrix, so that the inside and outer surface of the gel foam structure are loaded with methane oxidizing bacteria, and finally a microbial gel foam is obtained.

[0076] Comparative Example 2 A microbial gel foam is prepared from the following components by weight: 1.2 parts of sodium alginate, 0.12 parts of calcium L-lactate, 0.2 parts of alkyl glycoside, 0.1 parts of tea saponin, 3 parts of CO oxidizing bacteria liquid and 93.78 parts of deionized water; the CO oxidizing bacteria is Comamonas .

[0077] The preparation method of the microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1.2 parts of sodium alginate and fully dissolve it in 48.8 parts of deionized water. Then stir at 60° C. and 3000 r / min until no obvious flocculent material is left in the solution, thereby obtaining a sodium alginate solution.

[0078] Preparation of foam precursor: Weigh 0.2 parts of alkyl glycoside and 0.1 parts of tea saponin, dissolve them in 39.7 parts of deionized water, and mix them evenly at room temperature to obtain a composite foam precursor.

[0079] Preparation of the crosslinking agent: Weigh 0.12 parts of L-calcium lactate, dissolve it in 6.88 parts of deionized water, and stir at room temperature and a stirring speed of 1500 r / min until no visible particles or precipitation are left in the solution to obtain a L-calcium lactate solution.

[0080] S2. Cultivation of CO oxidizing bacteria liquid: The CO oxidizing bacteria seed liquid was inoculated into the CO oxidizing bacteria culture medium. The CO oxidizing bacteria culture medium used CO gas with a volume concentration of 10% as the sole carbon source. The CO oxidizing bacteria seed liquid and the CO oxidizing bacteria culture medium were uniformly mixed in a volume ratio of 2:8, and cultured at room temperature for 7 days to obtain the CO oxidizing bacteria liquid. The CO oxidizing bacteria culture medium was prepared according to the following components: 4.5 g of Na2HPO4·12H2O, 0.75 g of KH2PO4, 0.2 g of MgSO4· 7H2O, 1.5g of NH4Cl, 0.03g of CaCl2·6H2O and 0.69g of trace elements, 1L of water, pH value of 7, trace elements are obtained by mixing 0.1g of ZnSO4·7H2O, 0.3g of H3BO3, 0.03g of Na2MoO4·2H2O, 0.01g of CuCl2·2H2O, 0.03g of MnCl2·4H2O, 0.2g of CoCl2·6H2O and 0.02g of NiCl2·6H2O.

[0081] S3. Preparation of microbial gel foam: A sodium alginate matrix solution and a compound foam precursor are added to a mechanical stirrer and stirred and foamed at a stirring speed of 3000 r / min. After the liquid level is stabilized, a gel foam matrix solution is obtained. The CO oxidizing bacteria liquid is divided into three equal parts, and two parts of the CO oxidizing bacteria liquid are added to the gel foam matrix solution. After stirring and mixing, an L-calcium lactate solution is slowly added dropwise at a uniform speed under stirring. After mixing evenly, a microbial gel foam matrix is ​​obtained. Finally, one part of the CO oxidizing bacteria liquid is sprayed on the outer surface of the microbial gel foam matrix so that the CO oxidizing bacteria are loaded on both the inside and the outer surface of the gel foam structure, thereby obtaining a microbial gel foam.

[0082] Comparative Example 3 A microbial gel foam is prepared from the following components in parts by mass: 1.2 parts of sodium alginate, 0.12 parts of calcium L-lactate, 0.2 parts of alkyl glycoside, 0.1 parts of tea saponin, 3 parts of microbial liquid and 93.78 parts of deionized water; the microbial liquid is obtained by mixing methane oxidizing bacteria liquid and CO oxidizing bacteria liquid in a volume ratio of 1:2, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

[0083] The preparation method of the microbial gel foam comprises the following steps: S1. Preparation of gel matrix solution: Weigh 1.2 parts of sodium alginate and fully dissolve it in 48.8 parts of deionized water. Then stir at 60° C. and 3000 r / min until no obvious flocculent material is left in the solution, thereby obtaining a sodium alginate solution.

[0084] Preparation of foam precursor: Weigh 0.2 parts of alkyl glycoside and 0.1 parts of tea saponin, dissolve them in 39.7 parts of deionized water, and mix them evenly at room temperature to obtain a foam precursor of alkyl glycoside and tea saponin.

[0085] Preparation of the crosslinking agent: Weigh 0.12 parts of L-calcium lactate, dissolve it in 6.88 parts of deionized water, and stir at room temperature and a stirring speed of 1500 r / min until no visible particles or precipitation are left in the solution to obtain a L-calcium lactate solution.

[0086] S2. Cultivation of microbial culture: A methanotrophic bacteria seed solution was inoculated into a methanotrophic bacteria culture medium containing 10% CH4 gas by volume as the sole carbon source. The methanotrophic bacteria seed solution and the methanotrophic bacteria culture medium were uniformly mixed in a volume ratio of 2:8, and cultured at room temperature for 7 days to obtain a methanotrophic bacteria culture medium. The methanotrophic bacteria culture medium was prepared according to the following components: 0.717 g of Na2HPO4·12H2O, 0.272 g of KH2PO4, 1 g of MgSO4·7H2O, 1 g of KNO3, and 0.1 g of CaCl2·6H2O. , 0.25g FeCl3, 0.25g NH4Cl and 0.866g trace elements, 1L water, pH value is 7; trace elements are obtained by mixing 0.2g FeSO4·7H2O, 0.03g CuSO4·7H2O, 0.003g Na2MoO4·2H2O, 0.01g ZnSO4·7H2O, 0.003g MnSO4·H2O, 0.5g Na2EDTA, 0.048g CoCl2·6H2O, 0.062g / L H3BO3 and 0.01g NiCl2·6H2O.

[0087] The CO2 oxidizing bacteria seed liquid was inoculated into the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium used CO gas with a volume concentration of 10% as the sole carbon source. The CO2 oxidizing bacteria seed liquid and the methane oxidizing bacteria culture medium were evenly mixed in a volume ratio of 2:8 and cultured at room temperature for 7 days to obtain the CO2 oxidizing bacteria culture medium. The CO2 oxidizing bacteria culture medium was prepared according to the following components: 4.5g of Na2HPO4·12H2O, 0.75g of KH2PO4, 0.2g of MgSO4·7H2O, 1 0.5g of NH4Cl, 0.03g of CaCl2·6H2O and 0.69g of trace elements, 1L of water, pH value 7, trace elements are obtained by mixing 0.1g of ZnSO4·7H2O, 0.3g of H3BO3, 0.03g of Na2MoO4·2H2O, 0.01g of CuCl2·2H2O, 0.03g of MnCl2·4H2O, 0.2g of CoCl2·6H2O and 0.02g of NiCl2·6H2O.

[0088] The methane oxidizing bacteria liquid and the CO oxidizing bacteria liquid were mixed at a volume ratio of 1:2 to obtain a microbial liquid.

[0089] S3. Preparation of microbial gel foam: The sodium alginate matrix solution and the compound foam precursor are added into a mechanical stirrer, stirred and foamed at a stirring speed of 3000 r / min, and a gel foam matrix solution is obtained after the liquid level is stabilized; the microbial culture liquid is divided into three equal parts, 2 parts of the microbial culture liquid are added to the gel foam matrix solution, and after stirring and mixing, L-calcium lactate solution is slowly added dropwise at a uniform speed under stirring, and after mixing evenly, a microbial gel foam matrix is ​​obtained; finally, 1 part of the microbial culture liquid is sprayed on the outer surface of the microbial gel foam matrix, so that the inside and outer surface of the gel foam structure are loaded with microorganisms, and finally a microbial gel foam is obtained.

[0090] The performance test results of the microbial gel foams prepared in Examples 1 to 3 and Comparative Examples 1 to 3 are as follows: Table 1 Properties of microbial gel foams prepared in Examples 1 to 3 and Comparative Examples 1 to 3 As shown in Table 1, in Example 1, sodium alginate is used as a gelling agent, calcium L-lactate is used as a cross-linking agent, and sodium lauroyl glutamate is used as a foam precursor solution, which is mixed with methane oxidizing bacteria liquid and CO oxidizing bacteria liquid in a volume ratio of 1:1 to prepare a microbial gel foam. The carboxylate ions contained in the sodium alginate of the material react with the Ca in the calcium L-lactate to form a foam precursor solution. 2+ The interaction causes the macromolecular chains to entangle with each other, ultimately forming a gel foam with excellent stability. The foaming multiple of this material is 3.6 times. The beaker is tilted 45 degrees, and the time until the liquid surface does not move is the gelation time. After 7 minutes, the microbial gel foam of Example 1 loses its fluidity and stably adheres to the beaker. At this time, the microbial gel foam of Example 1 has completely gelled. Its decay process is observed at room temperature. After 149 hours, the microbial gel foam of Example 1 reaches its half-life.

[0091] In Example 2, sodium carboxymethyl cellulose is used as a gelling agent, aluminum citrate is used as a cross-linking agent, and glucono-δ-lactone is used as a pH modifier, and the mixture is stirred and mixed with the cocamidopropyl betaine foam precursor solution to obtain a gel foam. The cross-linking agent aluminum citrate of the gel foam can release cross-linking ions Al under acidic conditions. 3+ , forming a network gel structure through intramolecular cross-linking. Because its release rate is related to the pH value of the foaming solution, the gluconic acid- δ-Lactone adjusts the pH value of the foaming solution, controls the release rate of cross-linking ions, and thus controls the gelation time of the gel foam. The foaming multiple of this material is 3.4 times. The beaker is tilted 45°, and the time until the liquid surface does not move is the gelation time. After 9 minutes, the microbial gel foam of Example 2 loses its fluidity and stably adheres to the beaker. At this time, the microbial gel foam of Example 2 has completely gelled. Its decay process is observed at room temperature. After 107 hours, the microbial gel foam of Example 2 reaches its half-life.

[0092] In Example 3, sodium alginate is used as a gelling agent, calcium L-lactate is used as a crosslinking agent, and a composite surfactant of alkyl glycoside and tea saponin is used as a foam precursor solution. The microbial gel foam prepared by mixing the microbial solution with the methane oxidizing bacteria solution and the CO oxidizing bacteria solution in a volume ratio of 1:1 is obtained. The carboxylate ions contained in the sodium alginate react with the Ca in the calcium L-lactate. 2+ The reaction between the two molecules causes the macromolecular chains to entangle with each other, eventually forming a gel foam with excellent stability. Since alkyl glycosides have high foaming properties and tea saponin has good foam stability, they are compounded to improve the foaming system and foam stability, with a foaming multiple of 4.6 times. The beaker is tilted 45°, and the time until the liquid surface does not move is the gelation time. After 6 minutes, the microbial gel foam of Example 3 loses its fluidity and stably adheres to the beaker. At this time, the microbial gel foam of Example 3 has completely gelled. The decay process was observed at room temperature. After 185.5 hours, the microbial gel foam of Example 3 reached its half-life.

[0093] Compared to traditional foaming agents that rely solely on initial gas injection, the microbial gel foam prepared by the present invention directly increases the foaming multiple due to the fact that methane-oxidizing bacteria and CO-oxidizing bacteria produce CO2 gas as an additional gas source during their growth and metabolism to participate in foam formation. In addition, the continuous metabolism of the microorganisms prolongs the gas production time, allowing the foam to continue to expand slowly after formation. The present invention extends the half-life of the microbial gel foam by adding a composite of methane-oxidizing bacteria and CO-oxidizing bacteria to the gel foam. On the one hand, the CO2 gas continuously produced by the microorganisms in the foam can partially offset the bubble shrinkage caused by gas diffusion or liquid film rupture, thereby delaying the decay of the overall gel foam volume. On the other hand, the extracellular polymers secreted by the microbial metabolism and the gel matrix form a more complex three-dimensional network, thereby improving the mechanical strength of the gel foam and extending the half-life.

[0094] The present invention used Example 3, which achieved the highest foaming expansion ratio and foam stabilization, to compare different microorganisms in the same gel foam component, as in Comparative Examples 1 to 3. This comparison revealed that the foaming expansion ratio and half-life of the gel foam containing only methane-oxidizing bacteria, only CO-oxidizing bacteria, or a mixture of methane-oxidizing and CO-oxidizing bacteria at a volume ratio of 1:2 were lower than those of Example 3. The foaming expansion ratios of Comparative Examples 1 and 2 were 4.3 and 4.4, respectively. This is because CO-oxidizing bacteria only consume 0.5 mol of O₂ gas to convert 1 mol of CO₂ gas, while methane-oxidizing bacteria consume 2 mol of O₂ gas to convert 1 mol of CO₂ gas. Therefore, the foaming expansion ratio of Comparative Example 2 was higher than that of Comparative Example 1. However, since CO-oxidizing bacteria have a higher metabolic efficiency than methane-oxidizing bacteria, their high metabolic rate can lead to rapid depletion of O₂ at the foam edge, causing metabolic stagnation or even death of the CO-oxidizing bacteria, weakening the foam stabilization effect. Furthermore, the CO-oxidizing bacteria generate a large amount of CO₂ in a short period of time, causing a rapid increase in internal bubble pressure and accelerating bubble collapse. Therefore, the half-lives of Comparative Examples 1 and 2 were 190 hours and 186 hours, respectively. Because a single bacterial strain can only consume CH4 or CO, its practical application in goaf environments is limited by its single nature. It cannot simultaneously degrade combustible gases such as CH4 and CO in the goaf, and the presence of CO increases the risk of CH4 explosions. Therefore, the microbial gel foam of Comparative Example 3 was prepared by mixing a methane-oxidizing bacterial solution with a CO-oxidizing bacterial solution in a volume ratio of 1:2. It exhibited a foaming factor of 4.5, a gelation time of 6 minutes, and a half-life of 193 hours.

[0095] Figure 1 This is a diagram of gaseous metabolites of microorganisms in Example 3 of the present invention. Figure 1 As shown, the growth and metabolism of a mixed group of methanotrophic and CO-oxidizing bacteria in the gel-foam system revealed that methane and CO concentrations decreased over time. Initially, the methane concentration was high, approximately 9.47%, decreasing to 0.62% by the seventh day. The initial CO concentration was approximately 9.24%. On the second day, the metabolic rate accelerated, dropping the CO concentration to approximately 3.07%, and finally to 0% on the third day. This indicates that the methanotrophic and CO-oxidizing bacteria were able to continuously metabolize CH4 and CO in the gel-foam system. Furthermore, the CO-oxidizing bacteria metabolized CO at a rapid rate, consuming large quantities of CO in a short period of time. While metabolizing combustible gases such as CH4 and CO, the concentration of CO2 produced gradually increased. From the second to the fourth day, as methane and CO were continuously consumed, the CO2 production increased, reaching a peak of 6.81% on the fifth day. It then decreased slightly but remained at a high level. This demonstrates that the methanotrophic and CO-oxidizing bacteria were able to effectively function in the gel-foam system, metabolizing combustible gases such as methane and CO into inert CO2. In addition, compared Figure 2 and Figure 3The metabolic conditions of methane-oxidizing bacteria or CO-oxidizing bacteria in the gel-foam system indicate that the mixed bacteria can exert a synergistic effect and accelerate the metabolism of CH4 and CO gases.

[0096] Figure 2 This is a diagram of gaseous metabolites of microorganisms in comparative example 1 of the present invention. Figure 2 As shown, when the gel foam was loaded with methanotrophic bacteria, the initial CH4 gas concentration was 9.42%, which then decreased over time, reaching 0.25% on the seventh day. This indicates that the methanotrophic bacteria in the gel foam were able to continuously metabolize and consume CH4. Simultaneously, as the CH4 gas concentration continued to decrease, the concentration of CO2 produced continued to rise, with a slow increase from days 0 to 1, a significant increase from days 2 to 5, and a slowing increase after day 5, reaching a plateau between days 6 and 7. This suggests that initially, CH4 gas was abundant, methanotrophic bacteria were metabolically active, and CO2 continued to accumulate. As CH4 consumption gradually decreased, the rate of CO2 production slowed, but it continued to accumulate overall, eventually leveling off.

[0097] Figure 3 This is a diagram of gaseous metabolites of microorganisms in comparative example 2 of the present invention. Figure 3 As shown, when the gel foam was loaded with CO-oxidizing bacteria, the initial CO gas concentration was 9.6%, which then continued to decline over time, reaching 0% after 60 hours. This indicates that the CO-oxidizing bacteria in the gel foam were able to continuously metabolize and consume CO gas. Simultaneously, as the CO gas concentration continued to decline, the concentration of generated CO2 gas continued to rise, with a slow increase from 0 to 20 hours, a significant increase from 30 to 50 hours, and a plateau from 60 to 70 hours. This indicates that initially, CO gas was abundant, CO-oxidizing bacteria were metabolically active, and CO2 continued to accumulate. As CO consumption gradually decreased, the rate of CO2 production slowed, but it continued to accumulate overall before eventually leveling off.

[0098] Figure 4 The graph below shows the CO production of pure coal sample and microbial gel foam treated coal sample as a function of temperature. Figure 4As shown, 100 g of each of five coal samples with particle sizes of <0.9 mm, 0.9 mm to 3 mm, 3 mm to 5 mm, 5 mm to 7 mm, and 7 mm to 10 mm were weighed and mixed uniformly to produce 500 g of experimental coal samples. One portion was the original coal sample; one portion was added with the microbial gel foam from Example 3 and mixed uniformly to produce the microbial gel foam-retarded coal sample from Example 3; and one portion was added with the microbial gel foam from Comparative Example 3 and mixed uniformly to produce the microbial gel foam-retarded coal sample from Comparative Example 3. To prevent oxidation during drying, the retarded coal samples were dried openly in a vacuum drying oven at 30°C for 48 hours. A temperature-programmed experiment was then conducted. Fine-mesh gaskets were placed at the air outlet and inlet to prevent coal particles from clogging the pipes. The coal samples were then loaded and air was passed through the coal sample tank and pipes at 50 mL / min to check air tightness. If the air tightness is good, adjust the nitrogen flow rate to 80mL / min for 10 minutes to remove other residual gases in the pipeline. Then introduce dry air with a flow rate of 80mL / min for 10 minutes to remove residual nitrogen in the pipeline. Turn on the programmed temperature system, set the program temperature box heating rate to 1℃ / min, and the heating range to 30℃~180℃. When the temperature rises to the initial temperature, record the data, take gas samples every time the temperature rises by 10℃, and detect the change pattern of CO concentration. Compared with the raw coal, the CO release amount generated by the inhibited coal samples in Example 3 and Comparative Example 3 is lower than that in the raw coal, which shows that each microbial gel foam has the ability to inhibit coal spontaneous combustion, among which Example 3 has the best inhibitory effect on coal samples. This may be because the CO oxidizing bacteria in Comparative Example 3 consumes too much oxygen, resulting in a decrease in the activity of methane oxidizing bacteria, which leads to the collapse of the gel structure, and further causes the inhibitory effect of Comparative Example 3 to be slightly lower than that of the embodiment. Therefore, the microbial gel foam prepared by the present invention maintains good gel foam fluidity and extremely wide coverage, and can cover the surface of the coal sample to form a dense oxygen-isolating structure. The moisture and microorganisms in the microbial gel foam can reduce the temperature of the coal body, inhibit the coal-oxygen complex reaction, and reduce the concentration of CH4 and CO combustible gases in the goaf. It has the dual functions of preventing and controlling spontaneous combustion of coal in the goaf and eliminating combustible gases, fundamentally inhibiting the accumulation of combustible gases in the goaf, avoiding gas explosion accidents caused by excessive combustible gases, and ultimately achieving comprehensive prevention and control of spontaneous combustion of coal in the goaf and elimination of combustible gases.

[0099] It should be noted that when numerical ranges are mentioned in the present invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints may be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes preferred embodiments. Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they understand the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0100] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal, characterized in that: The preparation method is prepared from the following components in parts by weight: 1 to 2 parts of a gelling agent, 0.1 to 0.6 parts of a cross-linking agent, 0.2 to 0.4 parts of a surfactant, 1 to 3 parts of a microbial liquid, and 94 to 97.9 parts of water. The microbial solution is obtained by mixing the methane oxidizing bacteria solution and the CO oxidizing bacteria solution in a volume ratio of 1:0.5~1, wherein the methane oxidizing bacteria is Methylobacter , CO oxidizing bacteria are Comamonas .

2. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 1, characterized in that: The method for preparing the methane oxidizing bacteria liquid comprises the following steps: The methanotrophic bacteria seed liquid is inoculated into a methanotrophic bacteria culture medium using CH4 gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a methanotrophic bacteria liquid.

3. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 2, characterized in that: The volume concentration of CH4 gas in the culture medium is 10% to 20%, and the volume ratio of the methanotrophic bacteria seed solution to the methanotrophic bacteria culture medium is 1:2 to 9.

4. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 2, characterized in that: The methanotrophic bacteria culture medium is prepared according to the following components: 0.70g-0.72g of Na2HPO4·12H2O, 0.27g-0.28g of KH2PO4, 1g-1.2g of MgSO4·7H2O, 1g-1.2g of KNO3, 0.1g-0.2g of CaCl2·6H2O, 0.002g-0.006g of FeCl3, 0.20g-0.30g of NH4Cl and 0.694g-1.058g of trace elements, 1L of water, pH 7; trace elements are added at a rate of 0.15g-0. The obtained product is obtained by mixing 25g of FeSO4·7H2O, 0.02g~0.04g of CuSO4·7H2O, 0.002g~0.004g of Na2MoO4·2H2O, 0.01g~0.02g of ZnSO4·7H2O, 0.002g~0.004g of MnSO4·H2O, 0.4g~0.6g of Na2EDTA, 0.04g~0.05g of CoCl2·6H2O, 0.06g~0.07g of H3BO3 and 0.01g~0.02g of NiCl2·6H2O.

5. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 1, characterized in that: The method for preparing the CO oxidizing bacteria liquid comprises the following steps: The CO oxidizing bacteria seed liquid is inoculated into a CO oxidizing bacteria culture medium using CO gas as the sole carbon source, and cultured at room temperature for 5 to 7 days to obtain a CO oxidizing bacteria liquid.

6. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 5, characterized in that: The volume concentration of CO gas in the CO culture medium is 10% to 20%, and the volume ratio of the CO oxidizing bacteria seed solution to the CO oxidizing bacteria culture medium is 1:2 to 9.

7. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 5, characterized in that: The CO oxidizing bacteria culture medium was prepared according to the following components: 4.0g-5.0g Na2HPO4·12H2O, 0.7g-0.8g KH2PO4, 0.15g-0.25g MgSO4·7H2O, 1.0g-2.0g NH4Cl, 0.02g-0.04g CaCl2·6H2O and 0.6g-0.8g trace elements, 1L water, pH 7; trace elements were added at 0. 1g-0.2g of ZnSO4·7H2O, 0.2g-0.4g of H3BO3, 0.02g-0.04g of Na2MoO4·2H2O, 0.01g-0.02g of CuCl2·2H2O, 0.02g-0.04g of MnCl2·4H2O, 0.1g-0.3g of CoCl2·6H2O and 0.01g-0.03g of NiCl2·6H2O are mixed.

8. The microbial gel foam for suppressing explosion and inhibiting spontaneous combustion of coal according to claim 1, characterized in that: The gelling agent is at least one of sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and polyvinyl alcohol; the cross-linking agent is at least one of calcium chloride, calcium L-lactate, aluminum citrate, and sodium tetraborate; and the surfactant is at least one of sodium lauryl sulfate, sodium lauroyl glutamate, cocamidopropyl betaine, lauryl betaine, tea saponin, and alkyl glycoside.

9. A method for preparing the explosion-suppressing and coal spontaneous combustion-retarding microbial gel foam according to any one of claims 1 to 8, characterized in that: The following steps are involved: Weigh the following by mass: 1-2 parts of gelling agent, 0.1-0.6 parts of cross-linking agent, 0.2-0.4 parts of surfactant, 1-3 parts of microbial liquid, and 94-97.9 parts of water; Divide water into three parts, dissolve the gelling agent in the first part of water to obtain a gel matrix solution; dissolve the surfactant in the second part of water to obtain a foam precursor; dissolve the crosslinking agent in the third part of water to obtain a crosslinking agent solution; The gel matrix solution and the foam precursor are mixed, and the mixed solution is foamed using the Waring-Blender method. After the gel foam matrix is ​​formed, the microbial liquid is divided into three equal parts. Among them, two parts of the microbial liquid are added to the gel foam matrix, and after uniform dispersion, the cross-linker solution is added under stirring. After uniform stirring, the microbial gel foam matrix is ​​obtained, and then the other part of the microbial liquid is evenly sprayed onto the surface of the microbial gel foam matrix, so that the inside and outer surface of the microbial gel foam matrix are loaded with microorganisms, and finally the microbial gel foam is obtained.

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