CN112922599B - Biological-high temperature gasification combined mining method for hydrogen production from coal - Google Patents
Biological-high temperature gasification combined mining method for hydrogen production from coal Download PDFInfo
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Abstract
The invention discloses a biological-high temperature gasification combined mining method for hydrogen production from coal, which comprises the following steps: drilling two horizontal well groups on the same horizontal plane in a coal seam, and setting a casing for well cementation; hydraulic fracturing is carried out on the two wells simultaneously to form a boundary fracture gap network; performing alkali treatment on a coal seam, injecting coal-based hydrogen-producing microbial liquid into the coal seam in two horizontal wells, enabling strains to diffuse along critical fractures, dynamically monitoring the temperature and pressure conditions of the strains to prevent the strains from being inactivated, promoting microorganisms to strip coal carbon hydrogen-containing functional groups and capture metabolism by using the temperature and pressure conditions of the coal seam, performing multi-stage degradation on organic components in coal to generate hydrogen, carbon dioxide and micromolecular acid, and realizing in-situ carbon-hydrogen separation of the coal and preparing the hydrogen; discharging and extracting hydrogen after the bottom hole pressure reaches a peak value and is kept stable; and (3) gasifying and producing hydrogen for the remaining coal bed through the reaction of supercritical water and high-temperature carbon, and pumping gas and then injecting slurry to fill the combustion space area. The invention realizes low-carbon, green and high-efficiency development of coal by subverting the traditional coal mining technical system through biological-high-temperature gasification multistage utilization.
Description
Technical Field
The invention relates to the field of underground in-situ hydrogen production of coal, in particular to an underground microbial in-situ fermentation hydrogen production technology and a high-temperature gasification hydrogen production combined mining method of coal.
Background
About 70% of coal resources in China are stored below the surface kilometer, and with the severe consumption of the coal resources in the social development, the coal mining depth in China is increasing at the speed of 8-12 m/a, the middle east mining area is deepened at the speed of 10-25 m/a, and the shallow coal resources in China are expected to be exhausted in tens of years. With the increase of the mining depth, various problems faced by deep mining are more and more, and aiming at the mining environmental characteristics of five-high two-disturbance of deep coal resource mining, namely high ground stress occurrence condition, high working environment temperature, high water bearing pressure condition, high gas and high impact mine pressure tendency, strong mining stress disturbance and engineering disturbance of adjacent roadway groups, if the deep coal resource is mined by using the traditional coal mining method, a series of problems of low production efficiency, poor safety, serious ecological damage, low resource mining rate, large ground transportation/conversion energy loss and the like in the mining field are caused, and the development of the future coal industry is seriously influenced.
Carbon dioxide generated by coal combustion accounts for more than 70% of the total carbon dioxide emission amount in China and accounts for more than 90% of fossil energy, and the traditional coal industry chain is not beneficial to realizing the aims of carbon peak reaching and carbon neutralization in China, so that the adjustment and optimization of the structure and the energy structure of the coal industry should be accelerated, and particularly, the concept and the mode of traditional coal resource mining should be changed as soon as possible aiming at deep coal.
Compared with the combustion of coal bed gas such as coal or methane, the heat value of hydrogen is higher, and the combustion product is only water, so that the environment is not polluted, and therefore, the coal-based biological hydrogen technology is likely to become a main development direction in the field of coal bed gas biological engineering in the future.
Underground coal gasification is an exploitation method for converting solid resources into gaseous resources after organic components in coal are degraded in multiple stages underground by using microorganisms. The dark fermentation hydrogen production at the present stage is mainly an organic matter fermentation hydrogen production experiment, research on influencing factors, culture medium optimization and the like is performed, and research on microbial fermentation coal hydrogen production is less. The fermentation site of the existing coal microbial hydrogen production process is still positioned on the ground, the discharge amount of generated waste water, waste gas and waste residue is large, the environmental protection problem is very prominent, the treatment of the three wastes greatly increases the process investment, and the ground fermentation artificially produces a large amount of transportation cost.
The applicant found that: nutrient substances and hydrogen-producing flora are injected into the coal bed, the coal is degraded through the fermentation effect of the hydrogen-producing flora, or the microbial flora contained in the coal bed is activated by using a biotechnology, so that the flora is continuously proliferated and proliferated, the coal is converted into hydrogen, and the deep in-situ biodegradation fluidized mining of the coal can be realized. For the remaining coal bed after coal biodegradation, high-temperature gasification operation is adopted, namely hydrogen is prepared through the oxidation-reduction reaction of supercritical water and high-temperature carbon, and the biological-high-temperature combined mining hydrogen production of coal can be realized.
In the process of producing hydrogen by fermenting underground coal microorganisms, air seepage is less than 1% of coal bodies, and under the influence of facultative bacteria on the buffering action of a small amount of seepage air, the expansion effect of crack development on the specific surface area of the coal bodies is a main control factor for promoting the anaerobic fermentation of the coal bodies, and the more sufficient the crack development is, the larger the specific surface area of the coal bodies is, the higher the anaerobic fermentation rate of the coal bodies is improved. The hydraulic fracturing can generate a fracture gap net, provides conditions and places for microbial diffusion and fermentation, increases the specific surface area of the coal body, and further improves the hydrogen production efficiency.
Disclosure of Invention
The invention mainly aims to change the existing gas production mode of coal underground gasification, and utilizes coal-based hydrogen-producing microorganisms to ferment in situ in a coal seam and coal supercritical water underground gasification to produce hydrogen, carbon dioxide and micromolecule acid, thereby realizing the synergistic hydrogen production and reservoir permeability increase of coal underground microorganism fermentation and gasification.
In order to achieve the purpose, the invention adopts the following technical scheme:
a biological-high temperature gasification combined mining method for hydrogen production from coal is characterized by comprising the following steps:
the method comprises the following steps: drilling two horizontal wells to the coal seam in parallel along the direction of the minimum horizontal ground stress to the ground, and setting a casing pipe in the two horizontal wells and cementing the wells;
step two: detecting the temperature and pressure conditions in a coal bed in a drilled horizontal well through detection equipment, culturing coal-based hydrogen producing bacteria in a laboratory, taking mine water as a strain source, taking a coal sample as a fermentation substrate, enriching and culturing the hydrogen producing bacteria according to a hydrogen producing bacteria culture medium preparation method, ensuring an anaerobic environment in the culture process, wherein the culture temperature is 35 +/-0.5 ℃, and the pH value is maintained at 6, so that high-quality strains which are suitable for the stratum temperature and pressure conditions and have the hydrogen production rate of more than 100 mL/g are screened out to serve as microorganisms for in-situ hydrogen production through coal fermentation, culturing the enriched bacterial liquid in a constant-temperature culture box at 35 ℃ for 4 days, and storing the cultured bacterial liquid for later use after finishing;
step three: and (3) setting an experimental temperature and pressure condition according to a stratum environment, and screening the critical fracture density of high-activity diffusion of the strain. A circulating pump injection fracturing test simulating 3-6 cubic meters per minute low discharge capacity and 8-15 times per minute frequency under real stratum conditions is carried out in a laboratory, and fracturing pump injection parameters beneficial to forming critical fracture density in a coal bed are determined. Selecting the optimal pump injection parameters to perform a critical fracture fracturing test again, performing fracturing tracer injection-flowback monitoring in the fracturing process, simultaneously performing indoor micro-seismic monitoring, and determining tracer flowback characteristics and micro-seismic signal characteristics for generating critical fracture density;
step four: sequentially fracturing a horizontal well section from a well bottom to a well head by adopting a process of combining spiral perforation, bridge plug packing and pumping high-pressure fracturing liquid, carrying out retreating type staged fracturing on two horizontal wells in a coal bed, carrying out fracturing by adopting low-displacement optimal pumping parameters determined by laboratory tests, forming a fracturing network between coal intervals of the two horizontal wells, carrying out circulating pumping hydraulic fracturing at an optimal pumping frequency after preliminarily forming a fracturing network, analyzing fracture forms and fracture parameters after fracturing by using a fracturing tracer injection-flowback technology and a microseismic monitoring technology, and stopping circulating pumping when the tracer flowback characteristics and microseismic signal characteristics respectively accord with corresponding characteristics of critical fractures to form the critical fractures of the coal bed to be operated;
step five: plugging the part above the mined coal bed in the vertical well section, and pumping out the coal bed gas in the horizontal well section at the ground vertical well mouth through the pumping action of the negative pressure pipeline;
step six: performing alkalization pretreatment on a coal bed to ensure that the pH value of the coal bed to be operated is 6, injecting coal-based hydrogen-producing microbial liquid cultured in a laboratory into the coal bed through two horizontal wells, enabling hydrogen-producing microbes to diffuse along critical fractures, monitoring the temperature and pressure of strains in real time in the process of injecting the hydrogen-producing microbial liquid, controlling the temperature and pressure of the strains within a microbial activity range, promoting the microbes to strip coal carbon hydrogen-containing functional groups and capture metabolism by utilizing the temperature and pressure conditions of the coal bed after the injection of the bacteria liquid is finished, performing multi-stage degradation on organic components in coal to generate hydrogen, carbon dioxide and part of small molecular acid, and realizing the in-situ carbon-hydrogen separation of the coal and preparing the hydrogen;
the coal body fracture development is a key influence factor of the activity of coal-based hydrogen-producing microorganisms, and the anaerobic fermentation rate of the coal body is in positive correlation with effective nutrient substances which can be supplied by unit coal body and the specific surface area of the coal body. In coal bodies with air seepage less than 1%, under the influence of facultative bacteria on the buffer action of a small amount of seepage air, the larger the specific surface area of the coal body is, the larger the exposure amount of biodegradable organic matters is, the higher the anaerobic fermentation rate of the coal body is, and the higher the generation rate of anaerobic fermentation products represented by hydrogen is.
Step seven: in the microbial fermentation hydrogen production process, a pressure monitor is installed in a horizontal well section hydrogen production area, so that the environmental pressure of fermentation operation is monitored in real time, and the pressure is ensured to be within a normal pressure interval: 0.15-0.25 MPa, if the measured pressure exceeds 0.25 MPa, extracting partial hydrogen from the two wells to enable the pressure of the operation environment to return to a normal pressure interval, and when the pressure in the hydrogen production horizontal well section begins to drop and the pressure in the shaft under the stewing condition keeps unchanged, finishing the microbial fermentation hydrogen production process, completely extracting all hydrogen in the operation environment, and preparing to carry out subsequent high-temperature gasification operation;
step eight: for a left coal bed with increased pore gaps after biological hydrogen extraction, one of two horizontal wells is set as a combustion well, the other horizontal well is set as an extraction well, oxygen is injected and ignited by utilizing a perforation cluster in the combustion well, retreat type coal underground gasification operation is sequentially carried out, heat heats the coal bed between the combustion well and the extraction well through a fracture gap, pump injection pressure is kept when clean water is pumped and injected to the bottom of the well to reach more than 22.1 MPa in the extraction well, the clean water in the pore gap enters a supercritical state by utilizing the high-temperature condition that the coal bed is combusted to reach more than 374 ℃, and the high-pressure condition of 22.1 MPa formed by combining the ground stress and the pump injection pressure, so that the hydrogen is extracted from the extraction well when the high-temperature hydrogen production reaction of the well section is finished;
the gasification hydrogen production reaction of supercritical water and high-temperature carbon in the supercritical water pump injection fracturing process is as follows: c + H2O (supercritical) → CO2+H2+ precipitation with H2+O2→H2The in-situ high-temperature gasification hydrogen production technology of coal by using O (supercritical) cycle and supercritical water phase environment coal gasification as core utilizes a series of unique substances of water in supercritical state (the temperature and pressure reach or exceed critical point 374.3 ℃/22.1 MPa)Physicochemical property, supercritical water is used as homogeneous phase and high-speed reaction medium for coal gasification, and hydrogen and carbon elements in coal are gasified and converted into H2And CO2And part of water is decomposed into hydrogen, so that the high-efficiency clean conversion and utilization of the coal are realized.
Step nine: and (3) after the coal at the current perforation cluster of the two horizontal wells is sequentially transformed by biological-high temperature combustion gasification, grouting and filling the combustion space area, and repeating the high temperature gasification hydrogen production steps until all coal beds are transformed.
As a further preferable scheme, a coal seam with the buried depth of more than 1000 meters is used as an advantageous modified reservoir, two wells are vertically drilled and then are inclined to form a horizontal well section in the coal seam, and the two wells are parallel to each other.
As a further preferable scheme, the well spacing of the two wells is 400-500 m, the horizontal section length is 1000-3000 m, and the wells are drilled along the direction of the minimum horizontal ground stress.
As a further preferable scheme, the preparation method of the hydrogen-producing bacteria culture medium comprises the following steps: per 1000mL of sterile water were added: NH (NH)4Cl，1.0 g； K2HPO4·3H2O，0.4 g；NaCl，2.0 g；NaHCO3，2.0 g；MgCl2·6H2O, 0.1 g; tryptic casein, 1.0 g; 1.0 g of yeast extract; glucose, 10 g; 0.5 g of L-cysteine hydrochloride; 2.0 g of disodium ethylene diamine tetraacetate; 10 mL of trace element liquid, trace element liquid: per 1000mL of sterile water were added: nitrilotriacetic acid, 1.5 g; MnSO4·2H2O，0.5 g；MgSO4·7H2O，3.0 g；FeSO4·7H2O，0.1 g；NaCl，1.0 g；CoCl2·6H2O，0.1 g；CaCl2·2H2O，0.1 g；CuSO4·5H2O，0.01 g；ZnSO4·7H2O，0.1 g；H3BO3，0.01 g；KAl(SO4)2，0.01 g；NiCl·6H2O，0.02 g；Na2MoO4，0.01 g；。
As a further preferable scheme, the fracturing tracer injection-flowback technology is that trace substance tracers of different types such as La, Ce, Pr, Nd and the like with certain concentration are added into each section of fracturing fluid, after fracturing construction is finished, the concentration of the tracers in the flowback fluid is monitored at regular time, and fractured fracture morphology and fracture parameters can be obtained through comparative analysis.
As a further preferable scheme, the microseism monitoring technology is that a geophone is arranged in a horizontal well to monitor microseism waves induced in the fracturing process so as to describe the geometrical characteristics of a fracture network, the microseism monitoring technology is mainly used for positioning microseism events generated along with the fracturing process to obtain the length, height and azimuth angle information of artificial fractures, the actual fracturing effect and the expected fracturing effect can be compared and analyzed through microseism analysis, and then the fracturing scheme is optimized to improve.
As a further preferred scheme, the perforation completion is directionally carried out at a cluster interval of 30-50 meters.
As a further preferable scheme, the optimal low-displacement pumping parameters determined by laboratory tests are adopted to carry out staged clean water fracturing to preliminarily form a fracture network, the optimal displacement is 3-6 cubic meters per minute, the circulation pumping hydraulic fracturing is carried out at the optimal pumping frequency after the fracture network is preliminarily formed, the optimal frequency is 8-15 times per minute, the fractured fracture form and the fracture parameters after fracturing are analyzed by a fracture tracer injection-flowback technology and a microseismic monitoring technology, and the circulation pumping is stopped when the tracer flowback characteristic and the microseismic signal characteristic respectively accord with the corresponding characteristic of the critical fracture network size, so that the critical fracture network of the coal bed to be operated is formed.
As a further preferable scheme, the alkali treatment mode of the operation coal seam in advance is to inject a 6% NaOH solution into the coal seam through a combustion well and an extraction well, so that the pretreatment of the coal seam is favorable for improving the activity of hydrogenase in the hydrogen production process, and simultaneously can well reduce the crystallinity of coal, so that the lignin structure in the coal is broken, the crystallinity of cellulose and hemicellulose is reduced, and the method is favorable for improving the speed of stripping the carbon hydrogen-containing functional groups of the coal by microorganisms and capturing the hydrogen produced by metabolism.
As a further preferable scheme, the air seepage of the coal bed to be operated needs to be controlled to be less than 1%, under the influence of facultative anaerobes on the buffering action of a small amount of seepage air, the expansion action of crack development on the specific surface area of the coal body is a main control factor for promoting the anaerobic fermentation of the coal body, and the more sufficient crack development is, the larger the specific surface area of the coal body is, and the higher the anaerobic fermentation rate of the coal body is.
As a further preferable scheme, the coal-based hydrogen-producing microbial community is a typical coal anaerobic fermentation flora, and under the symbiotic action of various floras such as hydrogen-producing bacteria, hydrolytic bacteria, zymogens and methanogens, the community has the unique fermentation capability of degrading hydrogen-containing functional groups and other solid substances in coal into H2 (75-80%), CO2 (20-25%) and a small amount of small molecular acids (formic acid and acetic acid) under an absolute anaerobic condition.
As a further preferable scheme, the coal microbial gasification is divided into front and rear stages by using degradation link control and taking hydrogen production as a dividing point, and the coal biological hydrogen production is realized by exciting the front stage (hydrogen production section) and inhibiting the rear stage (methane production section).
As a further preferable scheme, after pumping liquid is stopped in a supercritical water pump injection well section of the extraction well, the combustion well controls oxygen injection to continue to combust a coal seam for gas production, the extraction well is stewed, clean water which is injected and is still in a supercritical state in the coal seam is enabled to continuously react with high-temperature carbon, hydrogen is fully produced, the temperature of the pump injection well section of the extraction well is monitored, when the temperature of the well section is raised to 200 ℃, the target gas production coal layer is basically combusted, and a combustion area is adjacent to the extraction well, the combustion well stops oxygen injection and stops combustion, and the high-temperature damage of the integrity of the extraction well is prevented; and (3) continuously soaking the well and monitoring the formation pressure of the hydrogen production coal seam, if the formation pressure is difficult to further increase, indicating that the gas production of the coal seam reaches the peak value, and starting gas extraction from the extraction well, wherein theoretically the hydrogen in the extracted gas accounts for more than 70%, and other gases such as methane, carbon monoxide and carbon dioxide account for within 30%.
As a further preferable scheme, after gas extraction is finished, cement slurry or a material with fluid state coagulability is injected into a burning well section of the burning well, and a burning empty area is filled, so that stratum settlement caused by large-range burning is prevented.
Has the advantages that:
(1) the invention realizes zero carbon emission, promotes low-carbon and green development of coal, and is beneficial to improving the utilization rate of coal. According to the invention, the coal is used as a raw material to prepare the biological hydrogen through an in-situ fermentation technology, the coal bed is left after the biological hydrogen preparation, the hydrogen is prepared by gasification through the reaction of supercritical water and high-temperature carbon, and nitrogen oxides and sulfides can hardly be detected in the gasification product, so that the emission of pollutants such as sulfur dioxide and nitrogen oxides and particulate matters such as PM2.5 can be fundamentally eliminated. The realization and popularization of the technology can relieve the current energy shortage problem and the environmental problem caused by fossil fuel combustion to a certain extent, and meanwhile, the technology also provides an effective and safe way for biological coal mining and provides a new thought for efficient mining and utilization of coal resources.
(2) The invention realizes biological and high-temperature multi-stage hydrogen production of coal, and greatly improves the development efficiency of hydrogen energy of coal. Compared with coal bed gas such as methane and the like, the heat value of the hydrogen is higher, and the combustion product of the hydrogen is only water, so that the environment is not polluted at all, so that the coal-based biological hydrogen technology is expected to become a main development direction in the field of coal bed gas biological engineering in the future. The invention relates to a method for preparing biological hydrogen from coal, belongs to a brand new research field, and provides a new way for obtaining clean energy, reducing emission of greenhouse gas, biologically mining coal and mining residual coal. The invention can be applied to the industrial technology of sustainable development and has very important value for optimizing the energy structure.
(3) The invention uses the drilling and mining technology to replace the underground mining, thereby fundamentally avoiding the difficult problems of various disasters and the like of the traditional mining. Along with the increase of mining depth, the difficult problems of ground temperature rise, ground pressure increase, complex coal bed hydrogeological conditions, coal transportation cost increase and the like become key influencing factors for limiting the exploitation of ultra-deep coal beds. The activity of the coal bed microorganisms requires water resources with high temperature and rich substances, and the pressure resistance of the microorganisms is high, so that the coal biological gasification technology can be well adapted to the geological conditions of ultra-deep coal beds. The invention can change a series of problems of low production efficiency, poor safety, serious ecological damage, low resource extraction rate, large ground transportation/conversion energy loss and the like in the field of mining industry at present, and realize the revolution of deep coal resource extraction concept and mode. The invention is based on the theory of deep in-situ fluidization mining of coal, overturns the traditional mining concept and technical system of coal, is a revolution of a new resource and energy mining mode, develops a new mining industrial mode, leads the mining technology revolution of mineral resources, realizes the green and environment-friendly mining target of 'no coal on the ground and no people under the well', and is beneficial to building a clean, safe, environment-coordinated and ecologically-friendly future deep coal operation space.
Drawings
FIG. 1 is a flow chart illustrating the steps of a bio-high temperature gasification combined production method for producing hydrogen from coal according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of the principle of hydrogen production by in-situ fermentation of coal-based hydrogen-producing microorganisms in a biological-high temperature gasification combined mining method for hydrogen production from coal;
FIG. 3 is a schematic diagram of supercritical water high-temperature gasification of coal in a biological-high-temperature gasification combined mining method for hydrogen production from coal;
1-coal seam; 2-a combustion well; 3, extracting the well; 4-coal-based hydrogen-producing microbial liquid; 5-hydrogen; 6-hydraulic fracturing of the critical fracture gap net area; 7-oxygen; 8-clear water; 9-underground coal gasification reaction zone.
Detailed Description
The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, which should be understood as being merely illustrative.
The coal bed is compact and poor in permeability, the original specific surface area of the coal body is small, the sufficiency and uniformity of microbial diffusion are low, the contact area between the coal-based hydrogen-producing microbial liquid and the coal body is small, the exposure of biodegradable organic matters is small, and effective nutrients supplied by the coal body per unit of the microbial liquid are insufficient, so that the anaerobic fermentation rate of the coal-based hydrogen-producing microbes in the coal bed is greatly limited, and the problem of the contact area between the coal-based hydrogen-producing microbes and the coal body in the in-situ hydrogen production by the coal microbes is solved.
Biological-high temperature gasification combined mining for hydrogen production from coal belongs to the field of physics, chemistry and biology interdisciplinary, and promotes microorganisms to strip hydrogen-containing functional groups of coal carbon and capture metabolism by utilizing the temperature and pressure conditions of a coal bed, so that organic components in the coal are subjected to multi-stage degradation to generate hydrogen, carbon dioxide and part of small molecular acid, and the in-situ carbon-hydrogen separation of the coal is realized and hydrogen is prepared. And carrying out supercritical water and high-temperature carbon reaction on the remaining coal bed with increased pore cracks after biological hydrogen extraction to gasify and produce hydrogen, thereby realizing the retreat type coal underground gasification hydrogen production.
The coal microbial hydrogen production process is characterized in that in the coal body with air seepage less than 1% in the underground coal microbial hydrogen production process, under the influence of facultative bacteria on the buffer action of a small amount of seepage air, the expansion effect of crack development on the specific surface area of the coal body is a main control factor for promoting the anaerobic fermentation of the coal body, and the more sufficient the crack development is, the larger the specific surface area of the coal body is, and the higher the anaerobic fermentation rate of the coal body is. The hydraulic fracturing can generate a fracture gap net, provides conditions and places for microbial diffusion and fermentation, increases the specific surface area of the coal body, and further improves the hydrogen production efficiency.
Considering the influence of stratum temperature and pressure conditions on microbial fermentation hydrogen production, a coal seam with the burial depth of more than 1000 meters is taken as an advantage to reform a reservoir, two horizontal wells positioned on the same horizontal plane are drilled to the coal seam in parallel along the direction of the minimum horizontal ground stress, the well spacing of the two wells is 400-500 meters, each horizontal well comprises a vertical well section and a horizontal well section, the length of the horizontal well section is 1000-3000 meters, the two wells are vertically drilled to form the vertical well section, then the two wells are inclined to form the horizontal well section in the coal seam, the two wells are parallel to each other, and two horizontal wells are cased and grouted for well cementation;
culturing coal-based hydrogen-producing bacteria in a laboratory under the condition of temperature and pressure in a drilled coal bed, taking fresh mine water as a strain source, taking a fresh coal sample as a fermentation substrate, enriching and culturing the hydrogen-producing bacteria according to a hydrogen-producing bacteria culture medium preparation method, ensuring a strict anaerobic environment in the culture process, keeping the culture temperature (35 +/-0.5) DEG C and the pH at about 6, screening out high-quality strains which are suitable for the stratum temperature and pressure condition and have the hydrogen production rate of more than 100 mL/g as microorganisms for in-situ hydrogen production of coal, placing the enriched bacterial liquid in a constant-temperature culture box at 35 ℃ for culture for 4 days, and storing the cultured bacterial liquid for later use after the culture is finished;
the preparation method of the hydrogen producing bacteria culture medium comprises the following steps: per 1000mL of sterile water were added: NH (NH)4Cl，1.0 g； K2HPO4·3H2O，0.4 g；NaCl，2.0 g；NaHCO3，2.0 g；MgCl2·6H2O, 0.1 g; tryptic casein, 1.0 g; 1.0 g of yeast extract; glucose, 10 g; 0.5 g of L-cysteine hydrochloride; 2.0 g of disodium ethylene diamine tetraacetate; 10 mL of trace element liquid, trace element liquid: per 1000mL of sterile water were added: nitrilotriacetic acid, 1.5 g; MnSO4·2H2O，0.5 g；MgSO4·7H2O，3.0 g；FeSO4·7H2O，0.1 g；NaCl，1.0 g；CoCl2·6H2O，0.1 g；CaCl2·2H2O，0.1 g；CuSO4·5H2O，0.01 g；ZnSO4·7H2O，0.1 g；H3BO3，0.01 g；KAl(SO4)2，0.01 g；NiCl·6H2O，0.02 g；Na2MoO4，0.01 g；
Method for screening fracture density to be 4 multiplied by 10 through nuclear magnetic resonance and CT scanning5~2×106 mm2Coal samples in the range of/g. Setting experiment temperature and pressure conditions according to the stratum environment, dividing the screened coal samples into a plurality of groups of experiment group coal samples, respectively injecting equal amounts of fluorescently-labeled microorganism culture solution into each experiment group coal sample, and carrying out strain diffusion experiments. And after the microorganisms freely diffuse in the same time, slicing and cutting the coal samples, observing and identifying the strain diffusion range through a microscope, selecting the experimental group coal sample with the best strain diffusion performance, and obtaining the critical fracture density of the experimental group coal sample.
According to the experimental rock mechanics similarity theory, real stratum conditions are simulated in a laboratory, indoor low-displacement fracturing pump injection tests of 3-6 cubic meters per minute are firstly carried out, the optimal low-displacement pump injection parameters with the fracturing fracture density closest to the critical fracture density are determined, then circulating pump injection fracturing tests with the frequency of 8-15 times per minute are carried out in fracturing fractures formed by the optimal low-displacement pump injection parameters, and the optimal pump injection frequency and the optimal displacement which are beneficial to forming the critical fracture density in a coal bed are determined.
The method comprises the steps of selecting the optimal pump injection parameters to carry out a critical fracture fracturing test again, carrying out fracturing tracer injection-flowback monitoring in the fracturing process, namely adding trace substance tracers of different types such as La, Ce, Pr, Nd and the like with certain concentration into each section of fracturing fluid, monitoring the concentration of the tracers in the flowback fluid regularly after fracturing construction is finished, obtaining fractured fracture morphology and fracture parameters through contrastive analysis, carrying out indoor microseismic monitoring simultaneously, and determining the tracer flowback characteristic and microseismic signal characteristic generating critical fracture density.
Sequentially fracturing from a well bottom to a well head in a horizontal well section by adopting a process of combining spiral perforation, bridge plug packing and pumping high-pressure fracturing liquid, and performing directional perforation well completion at a cluster interval of 30-50 m, wherein the horizontal well section adopts cluster-shaped spiral perforation and the positions of two well perforation clusters are basically consistent; the perforation is performed from the inside of the casing to the stratum through a perforation gun to form a fracture initiation point of hydraulic fracturing; the perforation clusters are cluster-shaped cracking points formed by the process in a one-time perforation mode. Carrying out retreating type staged fracturing on two horizontal wells in a coal seam, forming a fracturing network between coal seam sections of the two horizontal wells by adopting an optimal low-displacement pumping parameter (the optimal displacement between 3 and 6 cubic meters per minute) determined by a laboratory test, carrying out circulating pumping hydraulic fracturing at an optimal pumping frequency (the optimal frequency between 8 and 15 times per minute) after primarily forming the fracturing network, analyzing fracture morphology and fracture parameters after fracturing by using a fracturing tracer injection-flowback technology and a microseismic monitoring technology, wherein the microseismic monitoring technology is used for monitoring microseismic wave induced in the fracturing process by arranging a detector in the horizontal wells to describe the geometric characteristics of the fracturing network, mainly positioning microseismic events generated along the fracturing process, acquiring the length, height and azimuth angle information of artificial fractures, and carrying out contrastive analysis on the actual fracturing effect and the expected fracturing effect by means of microseismic analysis, the fracturing plan is then optimized for improvement. And stopping circulating pump injection when the tracer flow-back characteristic and the micro-seismic signal characteristic respectively accord with the corresponding characteristic of the critical seam network size so as to form the critical seam network of the coal bed to be operated.
The air seepage of a coal bed to be operated is controlled to be less than 1%, under the influence of facultative bacteria on the buffering action of a small amount of seepage air, the expansion effect of crack development on the specific surface area of the coal body is a main control factor for promoting the anaerobic fermentation of the coal body, the more the crack development is sufficient, the larger the specific surface area of the coal body is, the larger the exposure amount of biodegradable organic matters is, and the higher the anaerobic fermentation rate of the coal body is.
And plugging the part above the mined coal bed in the vertical well section, and pumping out the coal bed gas in the horizontal well at the ground vertical well mouth through the pumping action of the negative pressure pipeline.
After the coal bed gas is mined, the coal bed is subjected to alkalization pretreatment, NaOH solution with the mass concentration of 6% is injected into the coal bed through a combustion well and an extraction well, the pH value of the coal bed to be operated is about 6, the hydrogenase activity in the hydrogen production process is improved, the coal crystallinity can be well reduced, the lignin structure in the coal is broken, the cellulose and hemicellulose crystallization degree is reduced, and the method is favorable for improving the speed of stripping the coal carbon hydrogen-containing functional groups by microorganisms and capturing the hydrogen produced by metabolism.
Injecting coal-based hydrogen-producing microbial liquid cultured in a laboratory into a coal bed through two horizontal wells, so that hydrogen-producing microbes diffuse along a fracture network, arranging an electric thermocouple temperature sensor and a pore pressure sensor at a perforation cluster in the hydrogen-producing microbial liquid injection process, monitoring the temperature and pressure conditions of strains in real time, controlling the temperature and pressure of the microbial liquid within the microbial activity range, and if the temperature of the microbial liquid in the injection process is too low, increasing the temperature of the microbial liquid injected into a wellhead, otherwise, reducing the temperature of the injected microbial liquid; if the pressure of the microbial liquid in the injection process is measured to be too high, the discharge capacity of the injected bacteria liquid at the well mouth is reduced, otherwise, the discharge capacity of the injected bacteria liquid is increased. Promoting microorganisms to strip coal carbon hydrogen-containing functional groups and capture metabolism by utilizing a coal bed temperature and pressure condition after the injection of a bacterial solution is finished, performing multi-stage degradation on organic components in coal to generate hydrogen, carbon dioxide and partial small molecular acid, realizing in-situ carbon-hydrogen separation of the coal and preparing the hydrogen, performing degradation link control, taking hydrogen production as a dividing point, gasifying the coal microorganisms into front and rear stages, and inhibiting the rear stage (methane production stage) by exciting the front stage (hydrogen production stage) to realize biological hydrogen production of the coal;
the coal-based hydrogen-producing microbial community is a typical coal anaerobic fermentation community, and the community is subjected to hydrogen-producing bacteria and hydrolysisUnder the symbiotic action of various floras such as bacteria, zymophyte, methanogen and the like, the method has the function group containing hydrogen and other solid substances in the coal are degraded into H under the absolute anaerobic condition2（75~80%）、CO2(20-25%) unique fermentation capacity with a small amount of small molecular acid (formic acid and acetic acid);
in the microbial fermentation hydrogen production process, a pressure monitor is installed in a horizontal well section hydrogen production area, so that the environmental pressure of fermentation operation is monitored in real time, and the pressure is ensured to be within a normal pressure interval: 0.15-0.25 MPa, if the measured pressure exceeds 0.25 MPa, extracting partial hydrogen from the two wells to enable the pressure of the operation environment to return to a normal pressure interval, and when the pressure in the hydrogen production horizontal well section begins to drop and the pressure in the shaft under the stewing condition keeps unchanged, finishing the microbial fermentation hydrogen production process, completely extracting all hydrogen in the operation environment, and preparing to carry out subsequent high-temperature gasification operation;
for the remaining coal bed with increased pore gaps after biological hydrogen extraction, one of two wells is a combustion well, the other well is an extraction well, oxygen is injected into the combustion well by using a perforation cluster and ignition is carried out, retreat type coal underground gasification operation is sequentially carried out, heat heats the coal bed between the combustion well and the extraction well through the fracture gaps, pump injection pressure is kept when clean water is pumped into the extraction well until the pressure at the bottom of the well reaches more than 22.1 MPa, and the clean water in the pore gaps enters a supercritical state (374.3 ℃ and 22.1 MPa) by using the high-temperature condition that the coal bed is combusted to more than 374 ℃ and the high-pressure condition of 22.1 MPa formed by combining the ground stress and the pump injection pressure, so that hydrogen production by reaction and gasification of supercritical water and high-temperature carbon is realized. The supercritical water has the physical characteristics of gas permeability and liquid dissolving capacity and the chemical characteristics of strong oxidation capacity, and is used as a medium and a reactant for preparing hydrogen by high-temperature coal gasification, so that organic carbon molecules, hydrogen, methane and other gas molecules form a homogeneous or quasi-homogeneous reaction environment, pyrolysis and extraction are integrated, and the conversion rate of the high-temperature coal gasification hydrogen preparation reaction is favorably improved.
Stopping the pump when the bottom pressure of the pump injection clean water well is difficult to maintain, controlling oxygen injection by the combustion well to continue burning the coal bed gas production, extracting the well for soaking, enabling the injected clean water which is still in a supercritical state in the coal bed to continue reacting with high-temperature carbon, fully producing hydrogen, monitoring the temperature of the pump injection well section of the extraction well, and stopping oxygen injection and stopping burning when the temperature of the well section rises to 200 ℃ to indicate that the target gas production coal bed is basically burnt and a burning area is adjacent to the extraction well, so as to prevent the integrity of the extraction well from being damaged at high temperature; and (3) continuously soaking the well and monitoring the formation pressure of the hydrogen production coal seam, if the formation pressure is difficult to further increase, indicating that the gas production of the coal seam reaches the peak value, and starting gas extraction from the extraction well, wherein theoretically the hydrogen in the extracted gas accounts for more than 70%, and other gases such as methane, carbon monoxide and carbon dioxide account for within 30%.
After the coal at the current perforation clusters of the two horizontal wells is sequentially subjected to biological-high temperature combustion gasification transformation, cement slurry or a material with flow state coagulability is injected into the well section of the combustion well after the combustion is finished, and a combustion space area is filled, so that the formation settlement caused by large-range combustion is prevented. And repeating the high-temperature gasification to prepare hydrogen until all coal beds are transformed.
Referring to fig. 1, 2 and 3, the present application provides a biological-high temperature gasification combined mining method for hydrogen production from coal, which specifically includes the following steps and key methods:
step s 10: considering the influence of stratum temperature and pressure conditions on microbial fermentation hydrogen production, a coal seam 1 with the burial depth of more than 1000 meters is taken as an advantageous modified reservoir, two horizontal wells 1 and 2 which are positioned on the same horizontal plane are drilled in parallel along the direction of the minimum horizontal ground stress, the well spacing of the two wells is 400-500 meters, the horizontal section length is 1000-3000 meters, the two wells are drilled vertically firstly, then the horizontal well section is formed in the coal seam through deflection, the two wells are parallel to each other, and casing and grouting are performed for well cementation;
step s 11: culturing coal-based hydrogen-producing bacteria in a laboratory, screening out high-quality strains which are suitable for stratum warm-pressing conditions and have the hydrogen production rate of more than 100 mL/g as the microorganisms for producing hydrogen by in-situ fermentation of coal, placing the enriched bacterial liquid in a constant-temperature incubator at 35 ℃ for culture for 4 d, and storing the cultured coal-based hydrogen-producing microbial liquid 4 for later use after the culture is finished; and (3) setting an experimental temperature and pressure condition according to a stratum environment, and screening the critical fracture density of high-activity diffusion of the strain. A circulating pump injection fracturing test simulating 3-6 cubic meters per minute low discharge capacity and 8-15 times per minute frequency under real stratum conditions is carried out in a laboratory, and fracturing pump injection parameters beneficial to forming critical fracture density in a coal bed are determined. Selecting the optimal pump injection parameters to perform a critical fracture fracturing test again, performing fracturing tracer injection-flowback monitoring in the fracturing process, simultaneously performing indoor micro-seismic monitoring, and determining tracer flowback characteristics and micro-seismic signal characteristics for generating critical fracture density;
step s 12: sequentially fracturing from the bottom to the mouth of a horizontal well section by adopting a process of combining spiral perforation, bridge plug packing and pumping high-pressure fracturing liquid, and performing directional perforation well completion perforation and completion at a cluster interval of 30-50 m, wherein cluster-shaped spiral perforation is adopted for the horizontal wells 1 and 2, and the positions of perforation clusters of the two wells are basically consistent. Carrying out retreating type staged fracturing on two horizontal wells in a coal seam, forming a fracturing net by adopting low-displacement (the preferable displacement is 3-6 cubic meters per minute) pump injection determined by laboratory tests between coal seam sections of the two horizontal wells, carrying out hydraulic fracturing in a circulating pump injection mode after the fracturing net is preliminarily formed, analyzing the fractured fracture form and fracture parameters by using a fracturing tracer injection-flowback technology and a micro-seismic monitoring technology, stopping circulating pump injection when the tracer flowback characteristic and the micro-seismic signal characteristic respectively accord with the corresponding characteristic of a critical fracture, forming a hydraulic fracturing critical fracture net area 6 of the coal seam to be operated, plugging the part above the mined coal seam in a vertical well section, and extracting coal bed gas in a horizontal well through the pumping action of a negative pressure pipeline at a ground vertical well mouth;
step s 13: and (3) carrying out alkalization pretreatment on the coal seam, and injecting a NaOH solution with the mass concentration of 6% into the coal seam through two horizontal wells to enable the pH value of the coal seam to be operated to be about 6. Injecting coal-based hydrogen-producing microorganism liquid 4 into the coal seam 1 through two horizontal wells, enabling hydrogen-producing microorganisms to diffuse along the critical pressure fracture network 6, monitoring the temperature and pressure of a culture solution in real time in the process of injecting the hydrogen-producing microorganism liquid 4, controlling the temperature and pressure within the activity range of the microorganisms, promoting the microorganisms to strip coal carbon hydrogen-containing functional groups and capture metabolism by utilizing the temperature and pressure conditions of the coal seam after the injection of the bacteria liquid is finished, performing multi-stage degradation on organic components in coal to generate hydrogen 5, carbon dioxide and part of small molecular acid, and realizing the in-situ carbon hydrogen separation of the coal and preparing the hydrogen.
Step s 14: in the microbial fermentation hydrogen production process, a pressure monitor is installed in a horizontal well section hydrogen production area, so that the environmental pressure of fermentation operation is monitored in real time, and the pressure is ensured to be within a normal pressure interval: 0.15-0.25 MPa, if the measured pressure exceeds 0.25 MPa, extracting partial hydrogen from the two wells to enable the pressure of the operation environment to return to a normal pressure interval, and when the pressure in the hydrogen production horizontal well section begins to drop and the pressure in the shaft under the stewing condition is kept unchanged, finishing the microbial fermentation hydrogen production process, completely extracting all hydrogen 5 in the operation environment, and preparing to carry out subsequent high-temperature gasification operation.
Step s 15: and injecting oxygen 7 into the combustion well 2 by using a perforation cluster and igniting the residual coal bed with increased pore gaps after biological hydrogen extraction, sequentially performing retreating type coal underground gasification operation, heating the coal bed between the combustion well 2 and the extraction well 3 by heat through the fracture gaps, pumping clear water 8 into the extraction well 3 until the bottom hole pressure reaches more than 22.1 MPa, and keeping the pumping pressure, wherein the clear water in the pore gaps enters a supercritical state (374.3 ℃ and 22.1 MPa) by using a high-temperature condition of the coal bed combustion reaching more than 374 ℃ and a high-pressure condition of 22.1 MPa formed by combining the ground stress and the pumping pressure.
Step s 16: the supercritical water and the high-temperature carbon react to gasify to produce hydrogen, the pump is stopped when the bottom pressure of the pumped clean water well is difficult to maintain, the combustion well 2 controls the oxygen injection to continue to combust the coal seam to produce gas, the extraction well 3 is stewed, so that the injected clean water which is still in the supercritical state in the coal seam and the high-temperature carbon react continuously to produce hydrogen fully, the temperature of the pumped well section of the extraction well 3 is monitored, when the temperature of the well section is raised to 200 ℃, the target gas-producing coal layer basically burns completely and the combustion area 9 is adjacent to the extraction well 3, the combustion well 2 stops injecting oxygen and stops combustion, and the high-temperature damage to the integrity of the extraction well is prevented; and (3) continuing soaking the well and monitoring the formation pressure of the hydrogen production coal seam, if the formation pressure is difficult to further increase, indicating that the gas production of the coal seam reaches the peak value, and starting gas extraction by the extraction well 3, wherein theoretically, hydrogen in the extracted gas accounts for more than 70%, and other gases such as methane, carbon monoxide, carbon dioxide and the like account for within 30%.
Step s 17: after the coal at the current perforation clusters of the two horizontal wells is sequentially subjected to biological-high temperature combustion gasification transformation, cement slurry or a material with flow state coagulability is injected into the well section of the combustion well 2 after the combustion is finished, and a combustion dead zone is filled, so that the formation settlement caused by large-range combustion is prevented. And repeating the high-temperature gasification to prepare hydrogen until all coal beds are transformed.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (9)
1. A biological-high temperature gasification combined mining method for hydrogen production from coal is characterized by comprising the following steps:
the method comprises the following steps: drilling two horizontal wells to the coal seam in parallel along the direction of the minimum horizontal ground stress to the ground, and setting a casing pipe in the two horizontal wells and cementing the wells;
step two: detecting the temperature and pressure conditions in a coal bed in a drilled horizontal well through detection equipment, culturing coal-based hydrogen producing bacteria in a laboratory, taking mine water as a strain source, taking a coal sample as a fermentation substrate, enriching and culturing the hydrogen producing bacteria according to a hydrogen producing bacteria culture medium preparation method, ensuring an anaerobic environment in the culture process, wherein the culture temperature is 35 +/-0.5 ℃, and the pH value is maintained at 6, so that high-quality strains which are suitable for the stratum temperature and pressure conditions and have the hydrogen production rate of more than 100 mL/g are screened out to serve as microorganisms for in-situ hydrogen production through coal fermentation, culturing the enriched bacterial liquid in a constant-temperature culture box at 35 ℃ for 4 days, and storing the cultured bacterial liquid for later use after finishing;
step three: setting experiment temperature and pressure conditions according to the stratum environment, and selecting the critical fracture density of high-activity diffusion of the strain; carrying out a circulating pump injection fracturing test of 3-6 cubic meters per minute low discharge capacity and 8-15 times per minute frequency under the condition of simulating a real stratum in a laboratory, and determining fracturing pump injection parameters beneficial to forming critical fracture density in a coal bed; selecting the pumping parameters to perform a critical fracture fracturing test again, performing fracturing tracer injection-flowback monitoring in the fracturing process, simultaneously performing indoor micro-seismic monitoring, and determining tracer flowback characteristics and micro-seismic signal characteristics for generating critical fracture density;
step four: sequentially fracturing a horizontal well section from a well bottom to a well head by adopting a process of combining spiral perforation, bridge plug packing and pumping high-pressure fracturing liquid, carrying out retreating type staged fracturing on two horizontal wells in a coal bed, carrying out fracturing by adopting pumping parameters determined by a laboratory test, forming a fracturing network between coal seam sections of the two horizontal wells, carrying out circulating pumping hydraulic fracturing at the pumping frequency determined by the laboratory test after primarily forming a fracturing network, analyzing the fractured form and fracture parameters by using a fracturing tracer injection-flowback technology and a microseismic monitoring technology, and stopping circulating pumping when the tracer flowback characteristic and the microseismic signal characteristic respectively accord with the corresponding characteristic of a critical fracture so as to form the critical fracture of the coal bed to be operated;
step five: plugging the part above the mined coal bed in the vertical well, and pumping out the coal bed gas in the horizontal well section at the ground vertical well mouth through the pumping action of the negative pressure pipeline;
step six: performing alkalization pretreatment on a coal bed to ensure that the pH value of the coal bed to be operated is 6, injecting coal-based hydrogen-producing microbial liquid cultured in a laboratory into the coal bed through two horizontal wells, enabling hydrogen-producing microbes to diffuse along critical fractures, monitoring the temperature and pressure of strains in real time in the process of injecting the hydrogen-producing microbial liquid, controlling the temperature and pressure of the strains within a microbial activity range, promoting the microbes to strip coal carbon hydrogen-containing functional groups and capture metabolism by utilizing the temperature and pressure conditions of the coal bed after the injection of the bacteria liquid is finished, performing multi-stage degradation on organic components in coal to generate hydrogen, carbon dioxide and part of small molecular acid, and realizing the in-situ carbon-hydrogen separation of the coal and preparing the hydrogen;
step seven: in the microbial fermentation hydrogen production process, a pressure monitor is installed in a horizontal well section hydrogen production area, so that the environmental pressure of fermentation operation is monitored in real time, and the pressure is ensured to be within a normal pressure interval: 0.15-0.25 MPa, if the measured pressure exceeds 0.25 MPa, extracting partial hydrogen from the two wells to enable the pressure of the operation environment to return to a normal pressure interval, and when the pressure in the hydrogen production horizontal well section begins to drop and the pressure in the shaft under the stewing condition keeps unchanged, finishing the microbial fermentation hydrogen production process, completely extracting all hydrogen in the operation environment, and preparing to carry out subsequent high-temperature gasification operation;
step eight: for a left coal bed with increased pore gaps after biological hydrogen extraction, one of two horizontal wells is set as a combustion well, the other horizontal well is set as an extraction well, oxygen is injected and ignited by utilizing a perforation cluster in the combustion well, retreat type coal underground gasification operation is sequentially carried out, heat heats the coal bed between the combustion well and the extraction well through a fracture gap, pump injection pressure is kept when clean water is pumped and injected to the bottom of the well to reach more than 22.1 MPa in the extraction well, the clean water in the pore gap enters a supercritical state by utilizing the high-temperature condition that the coal bed is combusted to reach more than 374 ℃, and the high-pressure condition of 22.1 MPa formed by combining the ground stress and the pump injection pressure, so that the hydrogen is extracted from the extraction well when the high-temperature hydrogen production reaction of the well section is finished;
step nine: and (3) after the coal at the current perforation cluster of the two horizontal wells is sequentially transformed by biological-high temperature combustion gasification, grouting and filling the combustion space area, and repeating the high temperature gasification hydrogen production steps until all coal beds are transformed.
2. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: in the first step, a coal seam with the buried depth of more than 1000 meters is used as an advantage for modifying a reservoir, two horizontal wells are vertically drilled to form a vertical well section, after the coal seam is reached, the two horizontal wells are horizontally drilled to form a horizontal well section, and the two horizontal wells are parallel to each other.
3. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: in the first step, the well spacing of two horizontal wells is 400-500 meters, the horizontal well section length is 1000-3000 meters, and drilling is carried out along the direction of the minimum horizontal ground stress.
4. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: in the third step, the fracturing tracer injection-flowback technology is that trace substance tracers La, Ce, Pr and Nd with certain concentration are added into each stage of fracturing fluid, after fracturing construction is finished, the concentration of the tracers in the flowback fluid is monitored at regular time, and fractured fracture morphology and fracture parameters can be obtained through comparative analysis.
5. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: and in the fourth step, performing directional perforation completion at a cluster interval of 30-50 meters.
6. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: and step six, performing alkali treatment on the operation coal seam in advance in a mode of injecting NaOH solution with the mass concentration of 6% into the coal seam through a combustion well and an extraction well.
7. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: and step six, controlling the air seepage of the coal seam to be operated to be less than 1%.
8. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: step eight, after pumping liquid is stopped in a supercritical water pump injection well section of the extraction well, the combustion well controls oxygen injection to continue to combust the coal bed gas production, the extraction well is stewed, the injected clean water which is still in a supercritical state in the coal bed and reacts with high-temperature carbon continuously, hydrogen is fully produced, the temperature of the pump injection well section of the extraction well is monitored, when the temperature of the well section rises to 200 ℃, the target gas production coal layer is basically combusted, and a combustion area is adjacent to the extraction well, the combustion well stops oxygen injection and stops combustion, and the high-temperature damage of the integrity of the extraction well is prevented; and continuously soaking the well and monitoring the formation pressure of the hydrogen production coal seam, wherein if the formation pressure is difficult to further increase, the gas production of the coal seam reaches the peak value, the extraction well starts to extract gas, and the hydrogen in the extracted gas accounts for more than 70%.
9. The biological-high temperature gasification combined mining method for hydrogen production from coal according to claim 1, characterized in that: and step nine, after gas extraction is finished, injecting a material with flow state coagulability into the burning-finished well section of the burning well, and filling the burning-out area to prevent stratum settlement caused by large-range burning.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002034931A2 (en) * | 2000-10-26 | 2002-05-02 | Guyer Joe E | Method of generating and recovering gas from subsurface formations of coal, carbonaceous shale and organic-rich shales |
| CN101922287A (en) * | 2010-07-21 | 2010-12-22 | 肖栋 | Method for making natural gas by underground coal bed microorganism |
| CN102559772A (en) * | 2012-02-16 | 2012-07-11 | 北京科技大学 | Method for increasing production of coal bed methane by using exogenous microorganisms |
| CN104295276A (en) * | 2014-07-29 | 2015-01-21 | 太原理工大学 | Method for improving coalbed methane collection rate |
| CN105063093A (en) * | 2015-08-07 | 2015-11-18 | 河南理工大学 | Method for preparation of coalbed methane from microorganisms |
| CN105756637A (en) * | 2014-12-19 | 2016-07-13 | 中国石油天然气股份有限公司 | Method for increasing coal-bed gas recovery ratio by using coal-bed indigenous microbes |
| CN106285581A (en) * | 2016-08-23 | 2017-01-04 | 中国矿业大学(北京) | A kind of method utilizing origin bacterium to improve methane output |
-
2021
- 2021-04-08 CN CN202110379138.7A patent/CN112922599B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002034931A2 (en) * | 2000-10-26 | 2002-05-02 | Guyer Joe E | Method of generating and recovering gas from subsurface formations of coal, carbonaceous shale and organic-rich shales |
| CN101922287A (en) * | 2010-07-21 | 2010-12-22 | 肖栋 | Method for making natural gas by underground coal bed microorganism |
| CN102559772A (en) * | 2012-02-16 | 2012-07-11 | 北京科技大学 | Method for increasing production of coal bed methane by using exogenous microorganisms |
| CN104295276A (en) * | 2014-07-29 | 2015-01-21 | 太原理工大学 | Method for improving coalbed methane collection rate |
| CN105756637A (en) * | 2014-12-19 | 2016-07-13 | 中国石油天然气股份有限公司 | Method for increasing coal-bed gas recovery ratio by using coal-bed indigenous microbes |
| CN105063093A (en) * | 2015-08-07 | 2015-11-18 | 河南理工大学 | Method for preparation of coalbed methane from microorganisms |
| CN106285581A (en) * | 2016-08-23 | 2017-01-04 | 中国矿业大学(北京) | A kind of method utilizing origin bacterium to improve methane output |
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