Method and device for coordinated treatment and disposal of gas and coal gangue

Abstract

The present invention discloses a method and apparatus for the coordinated treatment and disposal of gas and coal gangue. The method involves constructing a methane-degrading bacteria reactor, using coal gangue as a carrier for the methane-degrading bacteria. Gas is introduced into the reactor, where methane is oxidized by methane-oxidizing bacteria on the gangue carrier to produce acid. The gangue is corroded by organic acids, weathering into soil. A bacterial liquid collection pool is provided at the bottom of the reactor for reflux. The method utilizes methane-degrading bacteria to degrade methane into organic acids, achieving biological carbon fixation. The organic acids produced by the biological oxidation of methane accelerate the corrosion and weathering of the gangue. Extracellular polymers and soluble microbial products produced by methane proliferation promote the aggregation of weathered gangue particles and enhance their fertilizer efficiency. The weathered gangue products can be used as soil for ecological restoration.

Description

Technical Field

[0001] The present invention belongs to the field of coordinated treatment and disposal of gas and coal gangue, and particularly relates to a method and device for coordinated treatment and disposal of gas and coal gangue. Background Art

[0002] Gas and coal gangue are major byproducts of coal production. Coal mine gas, primarily composed of methane, is a potent greenhouse gas with a greenhouse effect 21 times greater than that of carbon dioxide. High and medium concentrations of coal mine gas can be burned for power generation or as a chemical feedstock. However, low-concentration gas, due to a lack of effective utilization options, is often directly discharged, resulting in significant carbon emissions and energy waste.

[0003] Gangue is a solid waste emitted during coal mining and washing. Current treatment and disposal methods, such as gangue power generation and building material utilization, are limited in capacity due to technical and market constraints such as combustion calorific value and economic transport radius. While gangue's mineral composition is highly similar to soil, its larger size and lower fertilizer efficiency limit its ecological utilization. The key to its ecological utilization lies in rapidly pulverizing and reconstructing the gangue's mineral structure, improving the organic fertilizer efficiency of its weathering products, and achieving in-situ weathering of gangue into soil.

[0004] Aerobic methane oxidizing bacteria ( Aerobic methane-oxidizing bacteria, MOB ) can biocatalytically oxidize methane. Its metabolic process produces large amounts of organic matter, including organic acids, extracellular polymeric substances (EPS), and dissolved microbial products (SMP), thereby preventing methane from escaping into the atmosphere. Its contribution to global methane removal is as high as 10%–20%. The organic acids produced by methane biooxidation effectively accelerate the corrosion and weathering of coal gangue minerals. Extracellular polymeric substances and dissolved microbial products effectively increase the agglomeration of coal gangue weathering products, thereby achieving rapid weathering of the gangue into soil and improving its air permeability, moisture retention, and fertility storage properties.

[0005] Chinese Patent Application No. 202120425140.9 discloses a purification device for safely treating coal mine gas; Chinese Patent Application No. 201810759271.3 discloses a system and method for the combined aerobic and anaerobic microbial treatment of gas in mine goafs. These patents only address the degradation and treatment of coal mine gas and do not cover the coordinated treatment and disposal of coal gangue.

[0006] Based on this, it is necessary to invent a method and device for the coordinated treatment and disposal of gas and coal gangue. Summary of the Invention

[0007] The first objective of the present invention is to provide a method for the coordinated treatment and disposal of gas and gangue, and the second objective is to provide an apparatus for the coordinated treatment and disposal of gas and gangue. This invention utilizes organic acids produced by the biochemical degradation of methane by methanotrophic bacteria to accelerate the weathering and pulverization of gangue and its mineral decomposition and reconstruction. The extracellular polymers and soluble microbial products produced by the proliferation of methanotrophic bacteria effectively enhance the agglomeration of weathering products and the organic fertilizer efficiency of gangue weathering products, thereby achieving biological carbon sequestration of gas and rapid weathering of gangue into soil.

[0008] The first object of the present invention is achieved by: the method for co-processing and disposing of gas and coal gangue comprises the following steps:

[0009] (1) Using coal gangue as filler in biological filter;

[0010] (2) Spraying methane-oxidizing bacteria liquid into the biofilter, setting up a liquid collection pool at the bottom, and continuously reflux spraying;

[0011] (3) Pass the gas into the biofilter;

[0012] (4) The biologically weathered coal gangue is crushed to form soil for ecological restoration.

[0013] Preferably, the coal gangue includes washed gangue, hand-selected gangue, and a mixture discharged during the excavation of semi-coal roadways and rock roadways.

[0014] Preferably, the particle size of the coal gangue is ≥1 cm.

[0015] Preferably, the biofilter is arranged inside the stack reactor, and the biofilter can be replaced by a biofilter tower or a coal gangue pile.

[0016] Preferably, the biofilter in step (1) further comprises a biofilm carrier composed of biomass, and the biofilm carrier is any one or more of sugarcane bagasse, peanut shells, and coconut shells.

[0017] Preferably, the methane oxidizing bacteria liquid is obtained by enriching and culturing methane oxidizing bacteria, and the methane oxidizing bacteria include Methylobacterium ( Methylobacter ), Methylococcus ( Methylococcus ), Methylomonas ( Methylomonas ), Methylmicrobacterium ( Methylomicrobium ) and Methylsarcinia ( Methylosarcina ), Campylobacter methylotrophicus ( Methylosinus ) and Methylocystis ( Methylocystis ), subtype Ⅰb bacteria ( Methylococcus and Methylocaldum ) or a combination of the following.

[0018] Preferably, the spraying time of the methane oxidizing bacteria liquid is 2 hours, and the time interval is greater than 10 seconds.

[0019] Preferably, the gas is low-concentration gas, wherein the volume concentration of methane is ≤25%, and the amount of gas added is such that the gas-to-gangue gas-solid ratio is 1-500:1 (m 3 / kg).

[0020] Preferably, the bio-weathered gangue obtained in step (4) is sieved through a 6-mesh screen, and the material on the screen is collected and crushed until it passes through the screen to form soil for ecological restoration.

[0021] Furthermore, the bio-weathered coal gangue is crushed by a vibrating screen.

[0022] The second object of the present invention is achieved as follows: the device for co-processing and disposing of gas and gangue is a stack reactor, specifically comprising gangue (1), a gas inlet (2), a biofilm carrier (3), a filler inlet (4), a filler outlet (5), a bacterial liquid reflux spray device (6), and a bacterial liquid collection tank (7), wherein the filler inlet (4) is arranged at the top of the stack reactor, the gangue (1) and the biofilm carrier (3) are mixed evenly to form a mixed layer and arranged in the stack reactor, the filler outlet (5) is arranged at the bottom of the mixed layer, and a bacterial liquid collection tank (7) is further arranged below the mixed layer, the bacterial liquid in the bacterial liquid collection tank (7) is refluxed to the center of the top of the stack reactor through the bacterial liquid reflux spray device (6), and the gas inlet (2) is arranged at the bottom of the stack reactor and connected to the mixed layer.

[0023] The working process and working principle of the device of the present invention are as follows: first, the coal gangue (1) and the biofilm carrier (3) are mixed evenly and sent into the stack reactor through the filler inlet (4) to form a mixed layer, and then the bacterial liquid is sprayed. Then, gas is introduced from the gas inlet (2) for reaction. The sprayed bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection pool (7). It is then refluxed through the bacterial liquid reflux spraying device (6) and used for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 24-48 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0024] Part of the principles of the present invention are as follows:

[0025] (1) Methane in gas can be oxidized and metabolized by methane-oxidizing bacteria, which catalyzes its conversion into extracellular polymers (EPS), soluble microbial products (SMP), methanol, formaldehyde, organic acids, etc., thereby achieving rapid conversion of gas and biological carbon fixation.

[0026] (2) The characteristic minerals in the gangue are corroded and weathered by the organic acids produced by methane-oxidizing bacteria, resulting in a significant decrease in strength and pulverization of the structure. The characteristic minerals in the gangue undergo mineral decomposition and reconstruction, forming stable weathering products.

[0027] (3) Extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the methane biocatalytic conversion products can significantly improve the agglomeration of coal gangue weathering products, and the proliferated methane-oxidizing bacteria can improve the organic fertilizer effect of coal gangue weathering products.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The low-concentration gas produced in coal mines is oxidized by methane-degrading bacteria to achieve biological carbon fixation of low-concentration gas.

[0030] (2) The biochemical degradation products of gas accelerate the weathering and pulverization of coal gangue and the decomposition and reconstruction of minerals, effectively improving the soil properties of coal gangue weathering products such as air permeability, moisture retention, and fertilizer storage, and realizing the transformation of coal gangue from bulk solid waste properties to resource properties (soil). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a stack reactor for the coordinated disposal of gas and coal gangue according to the present invention.

[0032] In the figure, 1. coal gangue; 2. gas inlet; 3. biological filler; 4. filler inlet; 5. filler outlet; 6. bacterial liquid reflux spray device; 7. bacterial liquid collection tank. DETAILED DESCRIPTION

[0033] The present invention is further described below with reference to the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention fall within the scope of protection of the present invention.

[0034] Example 1:

[0035] like Figure 1 As shown, the biofilm carrier (3) composed of coal gangue (1) with a particle size of 1 cm and sugarcane bagasse and peanut shells is evenly mixed and sent into the biofilter through the filler inlet (4) to form a mixed layer, and then Methylococcus ( Methylococcus ), Methylsarcinia ( Methylosarcina ) and subtype Ⅰb ( Methylococcus and Methylocaldum ) is sprayed with the bacterial liquid obtained by enrichment culture, and then a methane volume concentration of 25% gas is introduced from the gas inlet (2) for reaction, wherein the gas to coal gangue gas-solid ratio is 1:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 24 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0036] Example 2:

[0037] like Figure 1 As shown, the biofilm carrier (3) composed of coal gangue (1) with a particle size of 1.5 cm and sugarcane bagasse and coconut shell is evenly mixed and sent into the biofilter tower through the filler inlet (4) to form a mixed layer, and then the methylmicrobacteria ( Methylomicrobium ) and Methylsarcinia ( Methylosarcina ), Campylobacter methylotrophicus ( Methylosinus ) and Methylocystis ( Methylocystis ), subtype Ⅰb bacteria ( Methylococcus and Methylocaldum ) The enriched cultured bacterial liquid is sprayed, and then methane with a volume concentration of 15% is introduced from the gas inlet (2) for reaction, wherein the gas-to-gangue gas-solid ratio is 200:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 28 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0038] Example 3:

[0039] like Figure 1 As shown, firstly, the coal gangue (1) with a particle size of 2 cm and the biofilm carrier (3) composed of peanut shells and coconut shells are mixed evenly to form a coal gangue pile and sent into the pile reactor through the filler inlet (4), and then Methylobacterium ( Methylobacter ), Methylococcus ( Methylococcus ) and Methylomonas ( Methylomonas ) The bacterial liquid enriched and cultured is sprayed, and then methane with a volume concentration of 1.5% is introduced from the gas inlet (2) for reaction, wherein the gas-to-gangue gas-solid ratio is 400:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 48 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0040] Example 4:

[0041] like Figure 1 As shown, the biofilm carrier (3) formed by coal gangue (1) with a particle size of 2.5 cm and sugarcane bagasse is mixed evenly and sent into the biofilter through the filler inlet (4) to form a mixed layer, and then Methylobacterium ( Methylobacter ) The enriched cultured bacterial liquid is sprayed, and then methane with a volume concentration of 1% is introduced from the gas inlet (2) for reaction, wherein the gas-to-gangue gas-solid ratio is 500:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 48 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0042] Example 5:

[0043] like Figure 1 As shown, the biofilm carrier (3) formed by coal gangue (1) with a particle size of 1.2 cm and peanut shells is mixed evenly and sent into the biofilter tower through the filler inlet (4) to form a mixed layer, and then Methyl Sarcina ( Methylosarcina ) and Campylobacter methylotrophicus ( ) is sprayed with the enriched cultured bacterial solution, and then a methane volume concentration of 20% gas is introduced from the gas inlet (2) for reaction, wherein the gas to coal gangue gas-solid ratio is 50:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 24 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

[0044] Example 6:

[0045] like MethylosinusAs shown, firstly, the coal gangue (1) with a particle size of 3 cm and the biofilm carrier (3) formed by coconut shell are mixed evenly to form a coal gangue pile and sent into the pile reactor through the filler inlet (4), and then Methylobacterium ( Figure 1 ), Methylococcus ( Methylobacter ), Methylomonas ( Methylococcus ), Methylmicrobacterium ( Methylomonas ) and Methylsarcinia ( Methylomicrobium ), Campylobacter methylotrophicus ( Methylosarcina ) and Methylocystis ( Methylosinus ), subtype Ⅰb bacteria ( Methylocystis and Methylococcus Methylocaldum ) The enriched cultured bacterial liquid is sprayed, and then methane with a volume concentration of 8% is introduced from the gas inlet (2) for reaction, wherein the gas-to-gangue gas-solid ratio is 300:1 (m 3 / kg). After spraying, the bacterial liquid passes through the mixed layer and is collected in the bacterial liquid collection tank (7). It is then returned through the bacterial liquid return spraying device (6) for spraying again. After the mixed layer is sprayed, the coal gangue reaches the optimal weathering effect after 48 hours and is discharged through the filler outlet (5). The obtained biologically weathered coal gangue is screened with a 6-mesh screen, and the screened material is collected and crushed by a vibrating screen until it passes through the screen, thereby forming soil for ecological restoration.

Claims

1. A method for the coordinated treatment and disposal of gas and coal gangue, characterized in that The method comprises the following steps: (1) Using coal gangue as filler in a biofilter; the biofilter also includes a biofilm carrier composed of biomass, and the biofilm carrier is any one or more of sugarcane bagasse, peanut shells, and coconut shells; (2) Spray methane-oxidizing bacteria solution into the biofilter, set up a bacteria solution collection pool at the bottom, and continuously reflux spray; (3) The gas is passed into the biofilter for biological weathering; the gas is low-concentration gas, wherein the volume concentration of methane is ≤25%, and the amount of gas added is 1-500:1 (m 3 / kg); (4) The biologically weathered coal gangue is crushed to form soil for ecological restoration.

2. The method for co-processing gas and coal gangue according to claim 1, characterized in that The coal gangue includes washed gangue, hand-selected gangue, and mixtures discharged during the excavation of semi-coal tunnels and rock tunnels.

3. The method for co-processing gas and gangue according to claim 1, characterized in that The coal gangue particle size is ≥1cm.

4. The method for co-processing gas and coal gangue according to claim 1, characterized in that The biofilter is arranged inside the stack reactor, and the biofilter can be replaced by a biofilter tower or a coal gangue pile.

5. The method for co-processing and disposing of gas and coal gangue according to claim 1, characterized in that The methane oxidizing bacteria liquid is obtained by enriching and culturing methane oxidizing bacteria, and the methane oxidizing bacteria include one or a combination of Methylobacterium, Methylococcus, Methylomonas, Methylmicrobacterium, Methylcampobacter and Methylocystis.

6. The method for co-processing gas and gangue according to claim 1, characterized in that The biologically weathered coal gangue obtained in step (4) is first passed through a 6-mesh sieve, and then the material above the sieve is collected and crushed until it passes through the sieve, and the material below the sieve is collected to obtain soil for ecological restoration.

7. A device for the coordinated treatment and disposal of gas and coal gangue, said device being used in the method for the coordinated treatment and disposal of gas and coal gangue according to any one of claims 1 to 6, characterized in that The device is a stack reactor, comprising coal gangue (1), a gas inlet (2), a biofilm carrier (3), a filler inlet (4), a filler outlet (5), a bacterial liquid reflux spray device (6), and a bacterial liquid collection pool (7). The filler inlet (4) is arranged at the top of the stack reactor, the coal gangue (1) and the biofilm carrier (3) are mixed evenly to form a mixed layer and arranged in the stack reactor, the filler outlet (5) is arranged at the bottom of the mixed layer, and a bacterial liquid collection pool (7) is further arranged below the mixed layer. The bacterial liquid in the bacterial liquid collection pool (7) flows back to the center of the top of the stack reactor through the bacterial liquid reflux spray device (6), and the gas inlet (2) is arranged at the bottom of the stack reactor and connected to the mixed layer.

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