System and method for preparing natural gas by ultrahigh-temperature steam-accelerated coal metamorphic evolution and hydrocarbon generation

Abstract

The present invention relates to the technical field of natural gas preparation, and in particular to a system and method for preparing natural gas by ultrahigh-temperature steam-accelerated coal metamorphic evolution and hydrocarbon generation. The system comprises: a feeding device used for pneumatically feeding pulverized coal; an accelerated coal metamorphic evolution and hydrocarbon generation reactor provided with a material steam inlet, a pulverized coal inlet, and a product outlet, wherein the material steam inlet is connected to a material steam supply device and used for inputting a material steam, and the pulverized coal inlet is connected to the feeding device; and a heating component used for heating the accelerated coal metamorphic evolution and hydrocarbon generation reactor. The natural gas preparation system and method of the present invention are derivative technologies established on the basis of studies on the formation mechanism of coalbed methane, are characterized by coal gasification without oxygen participation and carbon reactions conducted without hydrogen participation, overturn the traditional technical concept of coal-to-natural gas production, exhibit high energy efficiency, low energy consumption, high methane yield, and significant energy saving effect, and are advanced energy conversion technologies for realizing efficient and clean cascade utilization of coal.

Description

A system and method for accelerating coal metamorphism and hydrocarbon generation to produce natural gas using ultra-high temperature steam. Technical Field

[0001] This invention belongs to the field of natural gas production technology, and more specifically, relates to a system and method for producing natural gas by accelerating the metamorphic evolution of coal with ultra-high temperature steam. Background Technology

[0002] Coal is one of the most important fossil fuels on Earth. It evolved from ancient plant remains through complex geological processes spanning tens to hundreds of millions of years, undergoing different stages of physicochemical changes, ultimately forming coal and minerals of varying grades. Figure 1 shows the natural metamorphic evolution of coal and the names and annotations of different coal types. Peat is the initial stage of coal formation, formed from the partial decomposition and accumulation of plant remains in swampy wetlands under anaerobic conditions. At this stage, the organic matter has not yet been fully converted into coal, and it remains a low-calorific-value fuel. As the peat layer is covered by sediments and subjected to crustal subsidence, the temperature and pressure gradually increase, and the peat enters the lignite stage. Lignite still has a low calorific value and produces a lot of smoke and dust when burned, primarily used for power generation or as a chemical feedstock. Under even higher temperatures and pressures, lignite undergoes further dehydration and volatile matter removal, forming dense bituminous coal. The calorific value of bituminous coal significantly increases, making it one of the most important energy sources since the Industrial Revolution, widely used in power generation, coking, and steel smelting. When bituminous coal undergoes more intense metamorphic evolution, its volatile matter content decreases further, transforming it into anthracite. Anthracite is the highest grade of coal, but its reserves are scarce. Under extreme conditions, anthracite may completely lose its volatile matter, and its crystal structure may recombine into graphite. Graphite is a mineral resource used in industries such as batteries and lubricants.

[0003] During the long process of coal formation, plant remains are gradually transformed into solid fuels of different coal ranks through compaction, dehydration, and carbonization. Each metamorphic evolution also generates another important resource—coalbed methane (CBM). CBM, primarily composed of methane, is long-term stored in the micropores or fractures of the coal seam due to adsorption. As the degree of coalification deepens (especially in the transition from bituminous to anthracite), the increase in formation temperature and pressure promotes the generation of more methane from organic matter. Its methane content is usually closely related to coal rank, burial depth, and geological structure. As a clean energy source, the development and utilization of CBM can reduce the risk of underground gas explosions in coal mines, mitigate the ecological hazards of direct methane (a strong greenhouse gas) emissions, and supplement natural gas supply. While CBM possesses clean properties, the coal from which it is generated remains the primary target for pollution control. If CBM production can be increased while simultaneously making coal cleaner and more efficiently utilized, it will have a profound impact on the entire energy industry. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for accelerating the metamorphic evolution of coal to produce natural gas. This system and method revolutionize traditional coal-to-natural-gas technologies. The natural gas production process is environmentally friendly, simple, easy to operate, and has high efficiency and effectiveness. Furthermore, it improves the maturity of coal while producing natural gas, resulting in higher quality coal.

[0005] To achieve the above objectives, a first aspect of the present invention provides a system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas using ultra-high temperature steam, the system comprising:

[0006] Feeding device for pneumatic feeding of pulverized coal;

[0007] An accelerated coal metamorphism and evolution hydrocarbon generation reactor is provided with a material steam inlet, a pulverized coal inlet, and a product outlet. The material steam inlet is connected to a material steam supply device for inputting material steam, and the pulverized coal inlet is connected to the feeding device.

[0008] A heating element for heating the accelerated coal metamorphism and hydrocarbon generation reactor.

[0009] Optionally, the feeding device includes a storage tank, a screw conveyor, a feeding stabilizer, and a powder gas-solid mixer connected in sequence.

[0010] Optionally, the powder gas-solid mixer includes a mixer housing and a turbine centrifugal fan blade disposed within the mixer housing; the discharge stabilizer is connected to the powder gas-solid mixer housing via a first feed line and a second feed line respectively; the feed ends of the first feed line and the second feed line are tangent to the turbine centrifugal fan blade, and a discharge control valve is provided on the first feed line and the second feed line respectively; the outlet of the discharge stabilizer is provided with a reversing valve, which is used to control the two discharge control valves to open and close alternately.

[0011] Optionally, the accelerated coal metamorphism and hydrocarbon generation reactor includes a steam-powder mixer and a serpentine reaction tube connected to each other, the material steam inlet and the coal powder inlet are connected to the steam-powder mixer, and the product outlet is located at the end of the reaction tube.

[0012] Optionally, the steam powder mixer includes a steam powder mixer shell and a plurality of mixing chambers arranged sequentially from top to bottom and interconnected within the steam powder mixer shell. An annular gap is provided between the steam powder mixer shell and the outer walls of the plurality of mixing chambers, and each mixing chamber is connected to the annular gap. The middle part of the steam powder mixer shell protrudes outward to form a hemispherical annular steam pipe. The material steam inlet is located on the annular steam pipe, and the pulverized coal inlet is connected to the uppermost mixing chamber.

[0013] Optionally, the outer wall of the mixing chamber is provided with a plurality of steam inlets communicating with the annular gap, and each steam inlet is provided with a steam distribution pipe extending into the mixing chamber. The steam distribution pipe is bent. The bending directions of the steam distribution pipes of adjacent mixing chambers are opposite, and the steam distribution pipes of adjacent mixing chambers are offset from each other circumferentially.

[0014] Optionally, the plurality of mixing chambers include a first mixing chamber, a second mixing chamber, and a third mixing chamber arranged sequentially from top to bottom and interconnected with each other. The first mixing chamber and the second mixing chamber are interconnected through a central passage, and the second mixing chamber and the third mixing chamber are interconnected through peripheral passages.

[0015] Optionally, the system further includes a pulverized coal preparation device, a first temperature-controlled heat exchanger, a dust collector, a gas-solid-liquid separator, a desulfurizer, and a second temperature-controlled heat exchanger; the pulverized coal preparation device, the feeding device, the accelerated coal metamorphism and hydrocarbon generation reactor, the first temperature-controlled heat exchanger, the dust collector, the gas-solid-liquid separator, the desulfurizer, and the second temperature-controlled heat exchanger are connected in sequence; the outlet pipeline of the second temperature-controlled heat exchanger includes a first outlet pipeline and a second outlet pipeline, the first outlet pipeline is connected to the feeding device, and the second outlet pipeline is used to output finished natural gas.

[0016] A second aspect of the present invention provides a method for accelerating the metamorphic evolution of coal to produce natural gas, utilizing the above-described system, the method comprising:

[0017] Obtain pulverized coal;

[0018] Obtain material vapor at the first set temperature;

[0019] The pulverized coal is transported to the accelerated coal metamorphism and hydrocarbon generation reactor using natural gas as the transport gas, and the steam of the material is also input into the accelerated coal metamorphism and hydrocarbon generation reactor.

[0020] In the accelerated coal metamorphism and hydrocarbon generation reactor, under an oxygen-deficient environment and with the help of high-temperature steam, the accelerated coal metamorphism and hydrocarbon generation reaction takes place, producing natural gas and high-quality coal.

[0021] According to the present invention, the coal powder is mainly coal, such as coal mineral powder. Obtaining coal powder includes: obtaining coal of a predetermined mesh size; according to the method of the present invention, the coal powder particles should not be too large to facilitate the blowing of conveying gas and the mixing with reactants, and the predetermined mesh size is preferably 50 to 200 mesh.

[0022] According to the present invention, 0.5 to 50% of the coal mass of mineral powder containing iron, copper, cobalt and nickel can also be added to the reactant coal, and the ratio of iron, copper, cobalt and nickel can be adjusted to 4 to 5: 2 to 3: 2 to 1: 2 to 1 by adjusting the amount of mineral powder added.

[0023] The method proposed in this invention is based on the Temperature-Time Index (TTI) maturity evolution theory. It utilizes ultra-high temperature steam and ambient temperature to heat coal mineral powder within a short period. The ultra-high temperature steam acts as a ripening agent, pyrolysis agent, and hydrocarbon generation catalyst, promoting the coal mineral powder to reach maximum maturity in a short time. Furthermore, it simultaneously undergoes cracking and dealkylation reactions, thereby achieving hydrocarbon generation. Therefore, this invention's ultra-high temperature steam-accelerated coal metamorphic evolution hydrocarbon generation reaction technology produces both natural gas and high-quality coal, improving the maturity of the raw coal. It is a method for accelerating coal metamorphic evolution hydrocarbon generation reactions. The high-quality coal refers to high-grade coal as described in the background art and Figure 1, namely bituminous coal and anthracite.

[0024] In the term "ultra-high temperature steam" of this invention, ultra-high temperature refers to the first set temperature. Specifically, the first set temperature is 300℃ to 1200℃, preferably 700℃ to 1200℃, and can be any value or a range between any two of 700℃, 800℃, 900℃, 1000℃, 1100℃, and 1200℃.

[0025] The products of the accelerated coal metamorphism and hydrocarbon generation reaction of the present invention require a series of processing steps to obtain usable natural gas and high-quality coal. According to a preferred embodiment, the products of the accelerated coal metamorphism and hydrocarbon generation reaction sequentially pass through a first temperature-controlled heat exchanger, a dust collector, a gas-solid-liquid separator, a desulfurizer, and a second temperature-controlled heat exchanger. Dust removal is performed in the dust collector, and high-quality coal is output. After separation, desulfurization, and heat exchange in the gas-solid-liquid separator, desulfurizer, and second temperature-controlled heat exchanger, the natural gas is output. A portion of the natural gas is fed into the feeding device as a transport gas.

[0026] According to the present invention, optionally, after passing through the second temperature-controlled heat exchanger, the output product gas is further input into a methane catalytic device to further increase the concentration of natural gas.

[0027] According to the principles of the present invention, the accelerated coal metamorphic evolution hydrocarbon generation reaction is carried out in an oxygen-deficient environment. This oxygen-deficient environment can be provided by various means known in the art, such as using a closed reactor and controlling the oxygen content of the raw materials. The oxygen content of the oxygen-deficient environment described in this invention is no more than 1% by volume. According to a preferred embodiment of the present invention, the reactor is primarily filled with a natural gas atmosphere.

[0028] Conditions for accelerating the metamorphic evolution of coal and hydrocarbon generation can be controlled to achieve better hydrocarbon generation. According to a preferred embodiment of the present invention, the pressure for accelerating the hydrocarbon generation reaction of coal metamorphism is 0.1-2 MPa, preferably 0.1-1.5 MPa, and specifically can be any value or a range between any two of 0.1, 0.3, 0.5, 0.7, 0.9, 1.0, 1.2, and 1.5 MPa; the temperature for accelerating the hydrocarbon generation reaction of coal metamorphism is 500℃-1500℃, preferably 700℃-1200℃, and specifically can be any value or a range between any two of 700℃, 800℃, 900℃, 1000℃, 1100℃, and 1200℃; the time for accelerating the hydrocarbon generation reaction of coal metamorphism is 5s-100s, preferably 5s-90s, and specifically can be any value or a range between any two of 5s, 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, and 90s.

[0029] Optionally, the material steam is water vapor, and the mass ratio of the pulverized coal to the material steam is 1:0.5 to 1:10, preferably 1:0.5 to 1:5, specifically any value or a range between any two values ​​from 1:0.5, 1:1.5, 1:2, 1:2.5, 1:3, 1:5.

[0030] The beneficial effects of the technical solution of this invention are as follows:

[0031] (1) The natural gas preparation system of the present invention feeds pulverized coal into the pulverized coal inlet of the accelerated coal metamorphism and evolution hydrocarbon generation reactor through a feeding device. During the feeding process, natural gas is used as the conveying gas for pneumatic feeding. At the same time, material steam is introduced into the reactor from the material steam inlet. Under the heating effect of ultra-high temperature steam and heating components, the material undergoes metamorphism and evolution in the accelerated coal metamorphism and evolution hydrocarbon generation reactor. The hydrocarbon generation reaction of the material coal during the maturation process is utilized to realize the preparation of natural gas.

[0032] (2) The method for preparing natural gas of the present invention utilizes the accelerated coal metamorphism and hydrocarbon generation reaction of coal material. First, coal powder and ultra-high temperature material steam are obtained. Then, coal powder is introduced into the reactor using natural gas as the transport gas, and ultra-high temperature material steam is introduced at the same time, so that the accelerated coal metamorphism and hydrocarbon generation reaction occurs in the accelerated coal metamorphism and hydrocarbon generation reactor, and natural gas is further obtained.

[0033] (3) The natural gas production system and method of this invention are completely different from the existing international technologies for producing natural gas through coal gasification and methanation catalytic oxidation. This invention is a derivative technology based on the study of the formation mechanism of coalbed methane. It features coal gasification without the addition of oxygen and carbon reaction without the addition of hydrogen, overturning the traditional concept of coal-to-natural gas technology. Its gasification mechanism is based on the coalbed methane derivation process, in which surface organic matter is buried by crustal changes and undergoes a long process of gradual decomposition to generate hydrocarbons, mud formation to generate hydrocarbons, and coalification to generate hydrocarbons. While producing natural gas, the system and method of this invention also yield another reaction product—high-quality coal, which is also a clean fuel with great economic value.

[0034] (4) The natural gas preparation system and method of the present invention are environmentally friendly, simple in process, easy to operate, and have high processing efficiency, and can obtain high-purity natural gas. During the preparation process, the energy efficiency is high, the energy consumption is low, the methane yield is high, the energy saving effect is significant, the equipment occupies a small area, the initial investment cost is low, the applicability is wide, and it is easy to promote and use. Moreover, the operation steps are simple, the process is short, and the pollution is low. It is an advanced energy conversion technology for realizing the efficient and clean cascade utilization of coal.

[0035] (5) The natural gas preparation system and method of the present invention can be further applied to: 1. Upgrading of coal mining industry: Low-rank coal and washed coal sludge are converted into natural gas resources on-site and transported to the natural gas pipeline network through pipelines, which greatly improves the resource value of low-rank coal and washed coal sludge, reduces the traffic load burden caused by road transportation, and eliminates environmental pollution caused by coal transportation; 2. Producing low-cost natural gas for power generation: With the availability of low-cost natural gas resources, the gas-fired power generation industry will achieve significant development; 3. Peak shaving of natural gas pipeline network: The difficulty of peak shaving of natural gas pipeline network in winter is a huge supply burden in the energy consumption process. By using this method of natural gas preparation, natural gas pipeline network peak shaving stations can be established according to local conditions to solve the technical problems of peak shaving of urban gas supply, peak shaving of residential winter heating, and peak shaving of industrial gas; 4. Production of chemical raw materials: The product of the present invention, methane, is an important intermediate for many chemical raw materials.

[0036] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0037] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0038] Figure 1 shows the natural metamorphic evolution process of coal and the names and annotations of each coal type.

[0039] Figure 2 shows a process flow diagram of a method for producing natural gas by accelerating coal metamorphism and hydrocarbon generation using ultra-high temperature steam according to an embodiment of the present invention.

[0040] Figure 3 shows a process flow diagram of a method for producing natural gas by accelerating coal metamorphism and hydrocarbon generation using ultra-high temperature steam according to another embodiment of the present invention.

[0041] Figure 4 shows a schematic diagram of the overall structure of a system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas according to an embodiment of the present invention.

[0042] Figure 5 shows a schematic diagram of the feeding device of a system for producing natural gas from coal metamorphism and hydrocarbon generation using ultra-high temperature steam according to an embodiment of the present invention.

[0043] Figure 6 shows a schematic diagram of the structure of the powder gas-solid mixer of the feeding device according to an embodiment of the present invention.

[0044] Figure 7 shows a cross-sectional view of the powder gas-solid mixer of the feeding device according to an embodiment of the present invention.

[0045] Figure 8 shows a cross-sectional view of the feed stabilizer of the feeding device according to an embodiment of the present invention.

[0046] Figure 9 shows a schematic diagram of the structure of the accelerated coal metamorphic evolution hydrocarbon generation reactor according to an embodiment of the present invention.

[0047] Figure 10 shows a schematic diagram of the structure of a steam powder mixer according to an embodiment of the present invention.

[0048] Figure 11 shows a longitudinal sectional view of a steam powder mixer according to an embodiment of the present invention.

[0049] Figure 12 shows a cross-sectional view of a steam powder mixer according to an embodiment of the present invention.

[0050] Figure 13 shows a schematic diagram of the structure of a dust collector according to an embodiment of the present invention.

[0051] Figure 14 shows a schematic diagram of the structure of a gas-solid-liquid separator according to an embodiment of the present invention.

[0052] Figure 15 shows a schematic diagram of the structure of a temperature-controlled heat exchanger according to an embodiment of the present invention.

[0053] Explanation of reference numerals in the attached drawings: 1. Feeding device; 1-1. Storage tank; 1-2. Screw discharger; 1-3. Feed stabilizer; 1-4. Powder-to-solid mixer; 1-5. Mixer housing; 1-6. Turbine centrifugal fan blade; 1-7. First feed line; 1-8. Second feed line; 1-9. Discharge control valve; 1-10. Sealed bearing; 1-11. Reversing valve; 1-12. Speed ​​regulating motor; 1-13. Pressure relief control valve; 1-14. High-precision mass metering device; 1-15. Feeding air control valve; 1-16. Sealing groove; 2. Accelerated Coal Metamorphic Evolution Hydrocarbon Generation Reactor; 2-1. Material Steam Inlet; 2-2. Pulverized Coal Inlet; 2-3. Product Outlet; 2-4. Reaction Tube; 2-5. Steam-Powder Mixer; 2-51. Steam-Powder Mixer Shell; 2-52. First Mixing Chamber; 2-53. Second Mixing Chamber; 2-54. Third Mixing Chamber; 2-55. Annular Gap; 2-56. Annular Steam Pipe; 2-57. Steam Distribution Pipe; 2-58. Central Channel; 2-59. Peripheral Channel; 3. Pulverized Coal Preparation Device; 4. First Temperature-Controlled Heat Exchanger; 4-1. Gas-to-Gas Heat Exchanger; 4-2. First Gas-to-Water Heat Exchanger; 4-3, First output pipe; 4-4, Product inlet; 5, Dust collector; 6, Gas-solid-liquid separator; 6-1, Dehydration tank; 6-2, Dust removal tank; 7, Material steam supply device; 8, Heating component; 9, Desulfurizer; 10, Second temperature-controlled heat exchanger; 10-1, First outlet pipeline; 10-2, Second outlet pipeline; 10-3, Second gas-water heat exchanger; 10-4, Third gas-water heat exchanger; 10-5, Cooling water inlet; 10-6, Cooling water outlet; 10-7, Second output pipe; 10-8, Third output pipe; 11, Pressurization device; 12, Pressure regulator; 13, Recycled water tank; 14, Powder conveying gas tank; 15, Methane catalytic converter. Detailed Implementation

[0054] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0055] The technical principle of this invention is to accelerate the metamorphic evolution and hydrocarbon generation of coal ore powder in an oxygen-deficient environment using ultra-high temperature steam as the main means. This principle is based on the temperature-time index (TTI) maturity evolution theory, which utilizes the linear relationship between maturity and time. By heating the coal ore powder with steam and ambient temperature in a short period of time, the coal ore powder is accelerated to reach its maximum maturity in a short time, thereby realizing hydrocarbon generation, and further cracking and dealkylation reactions occur simultaneously.

[0056] Δt m -Time span of geological periods

[0057] The growth rate of maturation is generally 2 for every 10°C increase in temperature.

[0058] Δt m - The heating time (Ma) experienced during this interval;

[0059] T max T min - Maximum and minimum temperature interval;

[0060] m is a temperature index, aging rate index, or aging speed index in steps of 10℃. It is generally defined as m=0 corresponding to a temperature interval of 100~110℃, and m=1 corresponding to 110~120℃.

[0061] The TTI calculation formula can also be written in integral form:

[0062] t1 and t2 are the integral intervals of the reaction time, T t The temperature (°C) is time-dependent and determined by the reaction heat time. Coal powder is matured through short-time high-temperature steam catalysis, and a large amount of natural gas is released through hydrocarbon cracking in a short period.

[0063] Based on the above mechanism, the hydrocarbon generation process of different coal metamorphisms is as follows: when high-temperature steam of 500℃-1500℃ is injected, peat and lignite are transformed into bituminous coal or anthracite through the hydrocarbon generation process, bituminous coal is transformed into anthracite or semi-graphite through the hydrocarbon generation process, and anthracite is transformed into semi-graphite or graphite through the hydrocarbon generation process.

[0064] Furthermore, the hydrocarbon generation reaction mechanism of coal minerals and ultra-high temperature steam is analyzed as follows:

[0065] Coalbed methane can be classified into three types according to its origin: primary / secondary biogenic gas, thermal gas, and mixed-origin gas. The gas production mechanisms differ depending on the gas-producing process. The formation mechanism of thermal gas is considered to involve two hydrocarbon generation processes during the thermal cracking of coal powder: degradation and condensation. Degradation involves the sequential breakage of long chains and functional groups in the coal molecule structure based on their bond energies, generating small-molecule hydrocarbon gases. Condensation involves the condensation of aromatic nuclei within the coal molecule structure, producing small-molecule methane and hydrogen gases. The main reaction equations involved are as follows:

[0066] The reaction models involved are as follows:

[0067] t- represents the reaction time;

[0068] x represents the concentration of the reactant;

[0069] A- represents the video rate factor;

[0070] E- represents the apparent activation energy of the reactant;

[0071] R- is the gas constant;

[0072] T represents the reaction temperature.

[0073] The catalytic factors involved in the reaction are as follows:

[0074] Water vapor in high-pressure coal seams exhibits some characteristics of near-critical water, namely, it contains dissociated H3O. + and H - It already possesses some weak acid and weak base properties, exhibiting acid catalysis or base catalysis functions; the coal hydrocarbon generation process consists of two steps: pyrolysis and condensation. In the pyrolysis stage, as the temperature rises, coal molecules rapidly decompose, and in a steam environment, the gas production continuously increases with rising temperature. In the high-temperature condensation stage, the introduced H2O atmosphere effectively promotes the decomposition of coal molecules. As the water content increases, the C-C bonds in coal pyrolysis decrease, while the CH and CO bonds increase. The free radicals generated by coal pyrolysis react with H2O, promoting the decomposition of H2O molecules. The H2O decomposition produces H... + and OH - This further promotes coal pyrolysis and reacts with coal pyrolysis products to generate more gas.

[0075] The present invention will be described in more detail below through examples.

[0076] Example 1

[0077] The following describes in detail, with reference to the accompanying drawings, a system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas according to an embodiment of the present invention.

[0078] As shown in Figures 4 to 12, the system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas according to an embodiment of the present invention includes:

[0079] Feeding device 1 is used for pneumatic feeding of pulverized coal;

[0080] The accelerated coal metamorphism and evolution hydrocarbon generation reactor 2 is equipped with a material steam inlet 2-1, a coal powder inlet 2-2 and a product outlet 2-3. The material steam inlet 2-1 is connected to the material steam supply device 7 for inputting material steam, and the coal powder inlet 2-2 is connected to the feeding device 1.

[0081] Heating component 8 is used to heat and accelerate the metamorphic evolution of coal into hydrocarbon generation reactor 2.

[0082] Specifically, the feeding device 1 is used for pneumatic feeding of pulverized coal, and the conveying gas for pneumatic feeding is preferably natural gas. The heating element 8 is used to heat the accelerated coal metamorphic evolution hydrocarbon generation reactor 2 to reach the reaction temperature required for accelerating the coal metamorphic evolution hydrocarbon generation reaction. In Figure 4, the accelerated coal metamorphic evolution hydrocarbon generation reactor 2 is surrounded by the heating element 8 and is not visible.

[0083] Specifically, the system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas involves feeding pulverized coal into the pulverized coal inlet 2-2 of the accelerated coal metamorphism and hydrocarbon generation reactor 2 via a feeding device 1. Natural gas is used as the transport gas for pneumatic feeding during the process, while material steam is simultaneously introduced into the reactor 2 through the material steam inlet 2-1. The accelerated coal metamorphism and hydrocarbon generation reactor 2 is surrounded by heating components 8. Under the heating effect of ultra-high temperature steam and heating components 8, the pulverized coal undergoes an accelerated coal metamorphism and hydrocarbon generation reaction within the reactor 2 to produce natural gas.

[0084] Furthermore, the feeding device 1 includes a storage tank 1-1, a screw conveyor 1-2, a discharge stabilizer 1-3, and a powder-gas-solid mixer 1-4 connected in sequence. The storage tank 1-1 has a conical bottom, and the screw conveyor 1-2 is located below the storage tank 1-1. The screw conveyor 1-2 includes a housing and a screw installed inside the housing. The screw is driven by a speed-regulating motor 1-12 and can stably convey coal powder from the storage tank 1-1 to the discharge stabilizer 1-3. The discharge stabilizer 1-3 is a box-shaped structure, with its top connected to a feeding gas control valve, one side connected to the screw conveyor 1-2, and its bottom connected to a reversing valve 1-11. The powder-gas-solid mixer 1-4 includes a mixer housing 1-5 and a turbine centrifugal fan blade 1-6 installed inside the mixer housing. The feed stabilizer 1-3 is connected to the housing 1-5 of the powder-gas-solid mixer via the first feed line 1-7 and the second feed line 1-8, respectively. The feed ends of the first feed line 1-7 and the second feed line 1-8 are tangent to the turbine centrifugal fan blade 1-6. Each of the first feed line 1-7 and the second feed line 1-8 is equipped with a discharge control valve 1-9, and a reversing valve 1-11 controls the two discharge control valves 1-9 to open and close alternately. Each of the first feed line 1-7 and the second feed line 1-8 is also equipped with a feed gas control valve 1-15, and the reversing valve 1-11 controls the two feed gas control valves 1-15 to open and close alternately. Each feed gas control valve 1-15 is connected to a pressure relief control valve 1-13.

[0085] The pulverized coal in storage hopper 1-1 is conveyed to feed stabilizer 1-3 via screw conveyor 1-2, and then stably blown into pulverized gas-solid mixer 1-4 by feed gas (e.g., natural gas) from the upper part of feed stabilizer 1-3. To ensure the stability of pulverized coal conveying and eliminate backflow and gas blockage during the blowing process, pulverized coal is conveyed in two directions through reversing valve 1-11, two discharge control valves 1-9, and two feed gas control valves 1-15. The control valve 1-11 opens the discharge control valve 1-9 and the feed gas control valve 1-15 on one feed pipeline, controlling the feed gas and pulverized coal to be transported along this feed pipeline. After the predetermined transport time is reached, the corresponding pressure relief control valve 1-13 is briefly opened to release pressure. After pressure relief valve 1-13 closes, the control valve 1-11 reverses, closing the discharge control valve 1-9 and the feed gas control valve 1-15 on one feed pipeline, and opening the discharge control valve 1-9 and the feed gas control valve 1-15 on the other feed pipeline, controlling the feed gas and pulverized coal to be transported along the other feed pipeline. After the predetermined transport time is reached, the corresponding pressure relief control valve 1-13 is briefly opened to release pressure. This process is repeated. Through this operation, uninterrupted and stable pulverized coal transport is achieved. The feed gas control valve at the top of the feed stabilizer 1-3 can be opened normally or separately for both feed pipelines as needed. The depressurized gas can be collected through the filter (or dust bag) on ​​the top of the coal storage bin and returned to the coal storage bin, and then reused after being pressurized.

[0086] The feed ends of the first feed line 1-7 and the second feed line 1-8 are tangential to the turbine centrifugal fan blade 1-6, allowing the feed gas carrying pulverized coal to enter along the tangential direction of the turbine centrifugal fan blade 1-6. The airflow drives the turbine centrifugal fan blade 1-6 to rotate at high speed, thereby causing the pulverized coal entering the powder-gas-solid mixer 1-4 to be fully mixed with the airflow before being discharged. The angle of the turbine centrifugal fan blade 1-6 is tilted in the direction in which the first feed line 1-7 and the second feed line 1-8 enter the powder-gas-solid mixer 1-4 to ensure that the turbine centrifugal fan blade 1-6 can rotate smoothly at high speed.

[0087] Referring to Figures 9 to 12, in this embodiment, the accelerated coal metamorphism and hydrocarbon generation reactor 2 includes a steam-powder mixer 2-5 and a serpentine reaction tube 2-4 connected to each other. The material steam inlet 2-1 and the coal powder inlet 2-2 are connected to the steam-powder mixer 2-5, and the product outlet 2-3 is located at the end of the reaction tube 2-4.

[0088] The steam powder mixer 2-5 includes a steam powder mixer shell 2-51 and multiple mixing chambers arranged sequentially from top to bottom and interconnected within the steam powder mixer shell. In this embodiment, there are three mixing chambers: a first mixing chamber 2-52, a second mixing chamber 2-53, and a third mixing chamber 2-54. The steam powder mixer shell 2-51 is cylindrical, and each mixing chamber is also cylindrical. An annular gap 2-55 is provided between the steam powder mixer shell 2-51 and the outer walls of the multiple mixing chambers, and each mixing chamber communicates with the annular gap 2-55. The first mixing chamber 2-52 and the second mixing chamber 2-53 are interconnected through a central channel 2-58, and the second mixing chamber 2-53 and the third mixing chamber 2-54 are interconnected through a peripheral channel 2-59. The central channel 2-58 is located at the center of the mixing chamber, and the peripheral channel 2-59 is located on the outer periphery of the mixing chamber.

[0089] The outer shell 2-51 of the steam-powder mixer is cylindrical, with a hemispherical annular steam pipe 2-56 formed by an outward bulge in the middle. The material steam inlet 2-1 is located on the annular steam pipe 2-56, and the material steam enters the annular steam pipe 2-56 through the material steam inlet 2-1. The pulverized coal inlet 2-1 is connected to the uppermost mixing chamber, namely the first mixing chamber 2-52, and the pulverized coal enters the first mixing chamber 2-52 through the pulverized coal inlet 2-1.

[0090] Each mixing chamber has multiple steam inlets (e.g., three steam inlets) on its outer wall that communicate with the annular gap 2-55. Each steam inlet has a steam distribution pipe 2-57 extending into the mixing chamber. The steam distribution pipe 2-57 is bent, with its first section extending radially along the mixing chamber and its second section bent relative to the first section at an angle between 90° and 180°, for example, 120°. The steam distribution pipes 2-57 of adjacent mixing chambers have the same bending angle but opposite bending directions. The steam distribution pipes of adjacent mixing chambers are offset from each other circumferentially, for example, by 60°.

[0091] Material steam enters the annular steam pipe 2-56 through material steam inlet 2-1, then passes through the annular gap 2-55, the steam inlet on the outer wall of the mixing chamber, and the steam distribution pipe 2-57 before entering the mixing chamber. Pulverized coal enters the uppermost mixing chamber through pulverized coal inlet 2-1, where it mixes with the material steam, and then sequentially enters the lower mixing chambers for further mixing with the material steam. This structure of the mixing chambers and steam distribution pipes ensures that the pulverized coal and steam are fully mixed and form a swirling flow, which is beneficial for subsequent reactions.

[0092] The thoroughly mixed pulverized coal and material steam enter the reaction tube 2-4 from the steam-powder mixer 2-5. The reaction tube 2-4 is serpentine to ensure a sufficiently long reaction path and reaction time. After the reaction is complete, the product flows out from the product outlet 2-3 at the end of the reaction tube 2-4.

[0093] In this embodiment, the heating element 8 is disposed outside the accelerated coal metamorphism and hydrocarbon generation reactor 2, surrounding the reactor 2 to ensure the reaction temperature. Multiple temperature measuring tubes are spaced apart on the accelerated coal metamorphism and hydrocarbon generation reactor 2 to monitor the temperature inside the reactor, facilitating temperature control of the heating element 8.

[0094] Optionally, referring to Figure 2, the system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas also includes a pulverized coal preparation device 3, a first temperature-controlled heat exchanger 4, a dust collector 5, a gas-solid-liquid separator 6, a desulfurizer 9, and a second temperature-controlled heat exchanger 10. The pulverized coal preparation device 3, the feeding device 1, the reactor for accelerating coal metamorphism and hydrocarbon generation 2, the first temperature-controlled heat exchanger 4, the dust collector 5, the gas-solid-liquid separator 6, the desulfurizer 9, and the second temperature-controlled heat exchanger 10 are connected in sequence. The outlet pipeline of the second temperature-controlled heat exchanger 10 includes a first outlet pipeline 10-1 and a second outlet pipeline 10-2. The first outlet pipeline 10-1 is connected to the feeding device 1, and the second outlet pipeline 10-2 is used to output the finished natural gas.

[0095] Specifically, the process accelerates the metamorphic evolution of coal, producing hydrocarbons while also generating high-quality coal. The products of this process pass sequentially through the product inlet 4-4, including a first temperature-controlled heat exchanger 4, a dust collector 5, a gas-solid-liquid separator 6, a desulfurizer 9, and a second temperature-controlled heat exchanger 10. After dust removal in the dust collector 5, high-quality coal is output. Following further separation, desulfurization, and heat exchange in the gas-solid-liquid separator 6, desulfurizer 9, and second temperature-controlled heat exchanger 10, natural gas is output. High-quality coal refers to bituminous coal or anthracite.

[0096] Optionally, the first outlet pipeline 10-1 is connected to the feeding device 1 via a powder conveying gas tank 14, thereby using a portion of the natural gas as the conveying gas for the pulverized coal. A pipeline pressure boosting valve (not shown in the figure) is installed on the connecting pipeline between the powder conveying gas tank 14 and the feeding device 1 to enhance the pipeline's conveying capacity. A back pressure valve (not shown in the figure) is installed on the second outlet pipeline 10-2 to ensure the pressure of the reaction system.

[0097] Furthermore, the system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas using ultra-high temperature steam monitors and controls the input quality and temperature of raw materials, the temperature and pressure within the reactor, and the composition of the output. Specifically, the mass of pulverized coal fed into the accelerated coal metamorphism and hydrocarbon generation reactor 2 by the feeding device 1 is determined by the screw pitch 1-12 of the screw feeder 1-2 and the rotational speed of the speed-regulating motor. Therefore, adjusting the rotational speed of the speed-regulating motor controls the mass of the fed pulverized coal. In addition, a high-precision mass metering device 1-14 is installed at the bottom of the feeding device 1, which can accurately measure the actual mass of pulverized coal fed into the accelerated coal metamorphism and hydrocarbon generation reactor 2 by the feeding device 1. The flow rate of the feed gas can be controlled by controlling the opening duration of the reversing valve 1-11 and the feed gas control valve 1-15. Based on the actual mass of pulverized coal fed into the accelerated coal metamorphism and hydrocarbon generation reactor 2, the steam supply of the material steam supply device 7 is adjusted in real time (e.g., by a metering pump) to precisely control the mass of material steam fed into the accelerated coal metamorphism and hydrocarbon generation reactor 2 per unit time, so that the mass of pulverized coal and the mass of material steam are matched, preferably, the mass ratio of the two is 1:0.5 to 1:10.

[0098] The material steam supply device 7 can provide material steam at a first set temperature. The temperature inside the accelerated coal metamorphism and hydrocarbon generation reactor 2 is measured by a temperature measuring tube, and the operation of the heating element 8 is adjusted accordingly to bring the temperature inside the accelerated coal metamorphism and hydrocarbon generation reactor 2 to 500℃~1500℃. The first temperature-controlled heat exchanger 4 and the second temperature-controlled heat exchanger 10 can control the temperature of the product after heat exchange and can monitor the temperature of the circulating water; these are conventional techniques in the field and will not be elaborated further here.

[0099] A back pressure valve is installed on the second outlet pipeline 10-2 to control the pressure of the entire system. Preferably, the pressure inside the accelerated coal metamorphism and hydrocarbon generation reactor is controlled to be 0.1-2 MPa.

[0100] Furthermore, the product can be collected at the product outlet 2-3 and the outlet pipeline of the accelerated coal metamorphism and hydrocarbon generation reactor 2, and its composition, temperature and other parameters can be monitored and analyzed to make necessary adjustments.

[0101] Optionally, as shown in Figure 3, the system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas using ultra-high temperature steam also includes a methane catalytic device 15, which is connected downstream of the second temperature-controlled heat exchanger 10.

[0102] Specifically, due to the different types of coal used to produce pulverized coal, the methane content in the natural gas produced in the accelerated coal metamorphism and hydrocarbon generation reactor 2 varies. Depending on the intended use (LNG production), adding a methane catalytic device 15 can further increase the methane content and reduce the production cost of LNG.

[0103] Referring to Figures 13 to 15, the first temperature-controlled heat exchanger 4 includes a gas-to-gas heat exchanger 4-1 and a first gas-to-water heat exchanger 4-2, arranged in a two-stage heat exchange layout; the second temperature-controlled heat exchanger 10 includes a second gas-to-water heat exchanger 10-3 and a third gas-to-water heat exchanger 10-4, also arranged in a two-stage heat exchange layout. To facilitate the spatial arrangement of the heat exchangers, the second temperature-controlled heat exchanger 10 is positioned between the gas-to-gas heat exchanger 4-1 and the first gas-to-water heat exchanger 4-2. Each of the three gas-to-water heat exchangers is equipped with a cooling water inlet pipe and a cooling water outlet pipe, which converge to form a cooling water inlet 10-5 and a cooling water outlet 10-6.

[0104] The output end of the first gas-water heat exchanger 4-2 is connected to the first output pipe 4-3, which is connected to the dust collector 5. The output end of the dust collector 5 is connected to the gas-solid-liquid separator 6. The gas-solid-liquid separator 6 includes a dehydration tank 6-1 and a dust removal tank 6-2. The output end of the gas-solid-liquid separator 6 is connected to the desulfurizer 9. The output end of the desulfurizer 9 is connected to the cold fluid input end of the first gas-gas heat exchanger through the second output pipe 10-7. The cold fluid output end is connected to the second gas-water heat exchanger 10-3. The input end of the third gas-water heat exchanger 10-4 is connected to the methane catalytic converter 15 through the third output pipe 10-8.

[0105] Example 2

[0106] This embodiment provides a method for producing natural gas by accelerating coal metamorphic evolution and hydrocarbon generation using ultra-high temperature steam. This method is implemented using the ultra-high temperature steam-accelerated coal metamorphic evolution and hydrocarbon generation system described in Example 1. The process flow is shown in Figure 2. The method includes:

[0107] Coal powder is obtained from the coal powder preparation device 3; the coal powder is 50-200 mesh.

[0108] Material steam at a first set temperature is obtained from the material steam supply device 7; the first set temperature is 300℃~1200℃;

[0109] Natural gas is used as the transport gas to send pulverized coal to the accelerated coal metamorphism and hydrocarbon generation reactor 2, and material steam is also introduced into the accelerated coal metamorphism and hydrocarbon generation reactor 2. The accelerated coal metamorphism and hydrocarbon generation reaction takes place in the accelerated coal metamorphism and hydrocarbon generation reactor 2 to produce natural gas and high-quality coal.

[0110] The mass ratio of the pulverized coal to the steam of the material is 1:0.5 to 1:10;

[0111] The reactor for accelerating coal metamorphism and hydrocarbon generation is in a natural gas atmosphere with an oxygen content of no more than 1% by volume. The pressure inside the reactor is 0.1–1.5 MPa, and the temperature is 700℃–1500℃, thus creating an oxygen-deficient, high-temperature, and pressurized reaction state.

[0112] The products of the accelerated coal metamorphism and hydrocarbon generation reaction pass sequentially through the first temperature-controlled heat exchanger 4, dust collector 5, gas-solid-liquid separator 6, desulfurizer 9, and second temperature-controlled heat exchanger 10. Dust is removed in the dust collector 5 and powdered high-quality coal is output. After separation, desulfurization, and heat exchange in the gas-solid-liquid separator 6, desulfurizer 9, and second temperature-controlled heat exchanger 10, finished natural gas is output. Part of the natural gas is fed into the feeding device 1 through the powder conveying gas tank 14 as the conveying gas.

[0113] In summary, the natural gas preparation method provided by this invention utilizes a pulverized coal preparation device and a material steam supply device to transport pulverized coal and high-temperature material steam to an accelerated coal metamorphism and hydrocarbon generation reactor with oxygen-deficient, high-temperature, and pressurized conditions. The pulverized coal undergoes the accelerated coal metamorphism and hydrocarbon generation reaction, followed by cooling and heat exchange, dust removal, gas-solid-liquid separation, desulfurization, and further cooling and heat exchange processes to obtain pure natural gas and high-quality coal with greater economic value. Furthermore, a portion of the natural gas is used as the transport gas to transport the pulverized coal. This natural gas preparation method is environmentally friendly, simple, easy to operate, and highly efficient, producing high-purity natural gas. Its technological highlights include high energy efficiency, low energy consumption, high methane yield, significant energy savings, small equipment footprint, low initial investment cost, wide applicability, and ease of promotion and use. The method features simple operation steps, a short process, and low pollution, making it an advanced energy conversion technology for achieving efficient and clean cascade utilization of coal.

[0114] Example 3

[0115] As shown in Figure 3, the difference between this embodiment and Embodiment 2 is as follows:

[0116] In this embodiment, after passing through the second temperature-controlled heat exchanger 10, the output natural gas is further input into the methane catalytic device 15.

[0117] Because of the different types of coal used to produce pulverized coal, the methane content in the natural gas produced by the metamorphic evolution and hydrocarbon generation reaction in the accelerated coal metamorphic evolution hydrocarbon generation reactor varies. This method of natural gas production can also be further improved by adding a methane catalytic device according to the intended use (LNG production) to increase the methane content and reduce the cost of LNG production.

[0118] Example 4

[0119] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 950°C, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 4.44:1, the reaction temperature in the reactor is controlled at 950°C, and the reaction pressure is 0.5 MPa.

[0120] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 2.85 L / g, the methane production rate was 58.648%, the hydrogen production rate was 30.472%, the carbon monoxide production rate was 6.543%, and the carbon dioxide production rate was 4.072%.

[0121] Example 5

[0122] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 1000℃, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 2.18:1, the reaction temperature in the reactor is controlled at 1000℃, and the reaction pressure is 0.5MPa.

[0123] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production rate was 1.73 L / gL, the methane production rate was 39.683%, the hydrogen production rate was 41.835%, the carbon monoxide production rate was 11.479%, and the carbon dioxide production rate was 6.091%.

[0124] Example 6

[0125] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 950°C, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 0.9:1, the reaction temperature in the reactor is controlled at 950°C, and the reaction pressure is 0.5 MPa.

[0126] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 1.93 L / g, the methane production rate was 33.417%, the hydrogen production rate was 42.070%, the carbon monoxide production rate was 16.233%, and the carbon dioxide production rate was 7.929%.

[0127] Example 7

[0128] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 940°C, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 1.76:1, the reaction temperature in the reactor is controlled at 940°C, and the reaction pressure is 0.5 MPa.

[0129] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 1.86 L / g, the methane production rate was 33.823%, the hydrogen production rate was 42.108%, the carbon monoxide production rate was 15.935%, and the carbon dioxide production rate was 7.874%.

[0130] Example 8

[0131] This embodiment uses the system and method of Example 2, wherein the temperature of the material steam is 930°C, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 2.73:1, the reaction temperature in the reactor is controlled at 930°C, and the reaction pressure is 0.5 MPa.

[0132] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 1.49 L / g, the methane production rate was 52.284%, the hydrogen production rate was 33.488%, the carbon monoxide production rate was 8.101%, and the carbon dioxide production rate was 5.371%.

[0133] Example 9

[0134] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 850°C, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 1.39:1, the reaction temperature in the reactor is controlled at 850°C, and the reaction pressure is 0.5 MPa.

[0135] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 0.74 L / g, the methane production rate was 72.208%, the hydrogen production rate was 21.610%, the carbon monoxide production rate was 3.129%, and the carbon dioxide production rate was 2.540%.

[0136] Example 10

[0137] This embodiment uses the system and method of Embodiment 2, wherein the temperature of the material steam is 800℃, the coal powder is 100-mesh atomized coal mineral powder, the mass ratio of steam to mineral powder is 2.15:1, the reaction temperature in the reactor is controlled at 800℃, and the reaction pressure is 0.5MPa.

[0138] Using the method of this embodiment to produce methane gas, the gas production was measured using a mass flow meter and detected by a gas chromatograph: the gas production was 0.61 L / g, the methane production rate was 72.454%, the hydrogen production rate was 20.782%, the carbon monoxide production rate was 1.895%, and the carbon dioxide production rate was 4.256%.

[0139] The present invention is compared with traditional coal gasification technology as shown below:

[0140] (1) Resource consumption

[0141] A Comparison of the Ultra-High Temperature Steam-Accelerated Coal Metamorphism and Hydrocarbon Generation Technology for Natural Gas Production with Traditional Coal-to-Gas Technology

[0142] Total energy output includes primary products, by-products, and electricity.

[0143] Total energy input includes energy-valued raw coal, fuel coal, and purchased electricity.

[0144] (2) Process energy consumption and output ratio

[0145] 1Nm 3 Energy consumption and output of finished natural gas

[0146] Data source: "Discussion on Technical Indicators of Coal-to-Natural Gas Projects"

[0147] (3) Water consumption

[0148] A comparison of the water consumption per cubic meter of natural gas produced by the ultra-high temperature steam-accelerated coal metamorphism and hydrocarbon generation technology of this invention with that of traditional technologies.

[0149] The above comparison shows that the natural gas production technology of the present invention is significantly lower than that of existing technologies in terms of resource consumption, process energy consumption, and water consumption.

[0150] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A system for accelerating coal metamorphism and hydrocarbon generation to produce natural gas using ultra-high temperature steam, characterized in that, The system includes: Feeding device (1), used for pneumatic feeding of pulverized coal; The accelerated coal metamorphism and evolution hydrocarbon generation reactor (2) is provided with a material steam inlet (2-1), a coal powder inlet (2-2) and a product outlet (2-3). The material steam inlet is connected to a material steam supply device (7) for inputting material steam, and the coal powder inlet is connected to the feeding device. Heating component (8), the heating component being used to heat the accelerated coal metamorphism and hydrocarbon generation reactor.

2. The system according to claim 1, characterized in that, The feeding device includes a storage tank (1-1), a screw conveyor (1-2), a feeding stabilizer (1-3), and a powder gas-solid mixer (1-4) connected in sequence.

3. The system according to claim 2, characterized in that, The powder gas-solid mixer includes a mixer housing (1-5) and a turbine centrifugal fan blade (1-6) disposed within the mixer housing; The feed stabilizer is connected to the housing of the powder gas-solid mixer via a first feed line (1-7) and a second feed line (1-8). The feed ends of the first and second feed lines are tangent to the turbine centrifugal fan blades. Each of the first and second feed lines is provided with a discharge control valve (1-9). The outlet of the feed stabilizer is provided with a reversing valve (1-11), which is used to control the two discharge control valves to open and close alternately.

4. The system according to claim 1, characterized in that, The accelerated coal metamorphism and hydrocarbon generation reactor (2) includes a steam-powder mixer (2-5) and a serpentine reaction tube (2-4) connected to each other. The material steam inlet and the coal powder inlet are connected to the steam-powder mixer, and the product outlet is located at the end of the reaction tube.

5. The system according to claim 4, characterized in that, The steam powder mixer includes a steam powder mixer shell (2-51) and a plurality of mixing chambers (2-52, 2-53, 2-54) arranged sequentially from top to bottom and interconnected within the steam powder mixer shell. An annular gap (2-55) is provided between the steam powder mixer shell and the outer walls of the plurality of mixing chambers, and each mixing chamber is connected to the annular gap. The outer shell of the steam powder mixer has a hemispherical annular steam pipe (2-56) that protrudes outward from the middle. The material steam inlet is located on the annular steam pipe, and the coal powder inlet is connected to the uppermost mixing chamber.

6. The system according to claim 5, characterized in that, The outer wall of the mixing chamber is provided with multiple steam inlets communicating with the annular gap. Each steam inlet is provided with a steam distribution pipe (2-57) extending into the mixing chamber. The steam distribution pipe is bent. The bending directions of the steam distribution pipes of adjacent mixing chambers are opposite, and the steam distribution pipes of adjacent mixing chambers are offset from each other circumferentially.

7. The system according to claim 5, characterized in that, The plurality of mixing chambers include a first mixing chamber (2-52), a second mixing chamber (2-53), and a third mixing chamber (2-54) arranged sequentially from top to bottom and interconnected with each other. The first mixing chamber and the second mixing chamber are interconnected with each other through a central passage (2-58), and the second mixing chamber and the third mixing chamber are interconnected with each other through a peripheral passage (2-59).

8. The system according to claim 1, characterized in that, It also includes a coal powder preparation device (3), a first temperature-controlled heat exchanger (4), a dust collector (5), a gas-solid-liquid separator (6), a desulfurizer (9), and a second temperature-controlled heat exchanger (10); The coal powder preparation device, feeding device, accelerated coal metamorphism and hydrocarbon generation reactor, first temperature-controlled heat exchanger, dust collector, gas-solid-liquid separator, desulfurizer, and second temperature-controlled heat exchanger are connected in sequence. The outlet pipeline of the second temperature-controlled heat exchanger includes a first outlet pipeline (10-1) and a second outlet pipeline (10-2). The first outlet pipeline is connected to the feeding device, and the second outlet pipeline is used to output the finished natural gas.

9. A method for producing natural gas by accelerating coal metamorphism and hydrocarbon generation using ultra-high temperature steam, utilizing the system according to any one of claims 1-8, characterized in that, The method includes: Obtain pulverized coal; Obtain material vapor at the first set temperature; The pulverized coal is transported to the accelerated coal metamorphism and hydrocarbon generation reactor using natural gas as the transport gas, and the steam of the material is also input into the accelerated coal metamorphism and hydrocarbon generation reactor. In the accelerated coal metamorphism and hydrocarbon generation reactor, under an oxygen-deficient environment and with the help of high-temperature steam, the accelerated coal metamorphism and hydrocarbon generation reaction takes place, producing natural gas and high-quality coal.

10. The method according to claim 9, characterized in that, The products of the accelerated coal metamorphism and hydrocarbon generation reaction pass sequentially through a first temperature-controlled heat exchanger, a dust collector, a gas-solid-liquid separator, a desulfurizer, and a second temperature-controlled heat exchanger. Dust is removed in the dust collector, and high-quality coal is output. After separation, desulfurization, and heat exchange in the gas-solid-liquid separator, desulfurizer, and second temperature-controlled heat exchanger, the natural gas is output. A portion of the natural gas is fed into the feeding device as a transport gas. After passing through the second temperature-controlled heat exchanger, the output natural gas is also fed into a methane catalytic converter.

11. The method according to claim 9, characterized in that, Obtaining coal powder includes: obtaining coal powder of a set mesh size; the set mesh size is preferably 50 to 200 mesh.

12. The method according to claim 9, characterized in that, The first set temperature is 300℃~1200℃.

13. The method according to claim 9, characterized in that, The oxygen content in the oxygen-deficient environment is no more than 1% by volume; The pressure for accelerating the hydrocarbon generation reaction of coal metamorphism is 0.1–2 MPa, the temperature is 500℃–1500℃, and the time is 5s–100s.

14. The method according to claim 9, characterized in that, The material steam is water vapor, and the mass ratio of the pulverized coal to the material steam is 1:0.5 to 1:10.

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