Aqueous process for the production of natural gas

Abstract

The present application belongs to the field of coal chemical industry, and relates to a water method process for preparing natural gas. The method comprises the following steps: in an oxygen-isolated environment, atomized water-coal slurry raw material is contacted with high-temperature steam at 800-1000 DEG C, the system is subjected to multi-stage mixed heating to 200-400 DEG C, and then is continuously heated to the temperature required by pyrolysis reaction, and a product gas containing natural gas is obtained by reaction; the high-temperature steam serves as a pyrolysis agent, a reaction agent and an auxiliary catalyst, and the product gas serves as an atomizing agent for the water-coal slurry raw material. Through a simple process path, the present application improves the carbon-hydrogen polymerization efficiency and the heat utilization efficiency, and gets rid of the serious restriction of scale effect on the existing coal-to-natural gas technology and the dependence on external catalysts.

Description

Technical Field

[0001] This invention belongs to the field of coal chemical industry, specifically, it relates to a water-based process for producing natural gas. Background Technology

[0002] Coal-to-natural gas, as a clean industry, greatly conserves coal resources and increases the value of coal.

[0003] There are relatively few industrial-scale coal-to-natural gas (COG) plants in operation worldwide. my country has long been committed to the localization of the entire COG technology chain, but few have actually entered industrial application. The entire COG production process can be summarized as follows: raw coal reacts with high-purity oxygen and medium-pressure steam to produce crude coal gas; the crude coal gas undergoes sulfur- and oil-resistant shift conversion cooling and desulfurization and decarbonization to produce purified coal gas; the purified coal gas enters a methanation unit to synthesize methane, producing natural gas. The main process production units include air separation, a pulverized coal pressurized gasifier, a sulfur- and oil-resistant shift conversion unit, a gas purification unit, a methanation synthesis unit, and a wastewater treatment unit.

[0004] Methanation is one of the key technologies for converting coal into clean natural gas. Under high temperature, high pressure, and with the aid of a catalyst, carbon monoxide, carbon dioxide, and hydrogen generated from coal gasification are catalytically converted into methane. The methanation catalyst plays a crucial role in this chemical reaction and is a key factor limiting the self-sufficiency of my country's complete coal-to-natural-gas system. Since the mainstream process route is largely established, much research has focused on improving methanation catalysts. Summary of the Invention

[0005] Currently, global coal analysis and detection methods all employ oxidation methods, leading to the conclusion that coal-associated organisms are completely oxidized. However, the inventors have discovered that coal-associated organisms in nature contain a large number of unoxidized or incompletely oxidized elemental metals and non-metals. These elemental substances possess extremely strong oxidizing and hydrogenation / catalytic abilities. Based on this discovery, a water-based process for producing natural gas is proposed.

[0006] Specifically, the present invention provides a water-based process for producing natural gas. In an oxygen-isolated environment, atomized coal-water slurry feedstock is contacted with high-temperature steam at 800–1000°C. The system undergoes multi-stage mixing and heating to raise the temperature to 200–400°C, and then continues to raise the temperature to the temperature required for the pyrolysis reaction, thereby obtaining a product gas containing natural gas. The high-temperature steam serves as a pyrolysis agent, reactant, and auxiliary catalyst, and the product gas serves as an atomizing agent for the coal-water slurry feedstock.

[0007] The technical effects of this invention are reflected in:

[0008] (1) This technology is based on the isolation of oxygen, so the drawbacks of oxygen are minimal, and the generation of by-product oxides can be minimized. It can greatly improve the utilization efficiency of carbon elements, achieve a methane production rate of more than 80% in one step, and reduce the raw material cost by half.

[0009] (2) Since water is used as a pyrolysis agent, reactant, detergent and auxiliary catalyst, and elemental metals and elemental non-metals in coal by-products are used as catalysts, the process of the present invention generates only a small amount or no pollutants, is environmentally friendly, and eliminates the dependence on external catalysts.

[0010] (3) This invention improves hydrocarbon polymerization efficiency and heat utilization efficiency through a simplified process path, gets rid of the severe constraints of scale effect on existing coal-to-natural gas technology, can set the scale according to demand, and the technical equipment can be flexibly deployed.

[0011] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0012] 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 parts in the exemplary embodiments of the invention.

[0013] Figure 1 A schematic diagram of an apparatus for a water-based process for producing natural gas according to one embodiment of the present invention is shown.

[0014] Figure 2 A schematic diagram of an apparatus for a water-based process for producing natural gas, according to another embodiment of the present invention, is shown.

[0015] Figure 3 A schematic diagram of the equipment used in the water-based process for producing natural gas according to an embodiment of the present invention is shown.

[0016] Figure 4 The diagram shows a front view of a vortex-heated coal injection gun device used in an embodiment of the present invention.

[0017] Figure 5 The diagram shows a left-side view of a vortex-heated coal injection gun device used in an embodiment of the present invention.

[0018] Figure 6 The diagram shows a right-side view of a vortex-heated coal injection gun device used in an embodiment of the present invention.

[0019] Figure 7 It shows Figure 4 A schematic diagram of the cross-sectional structure along direction A.

[0020] Figure 8 A three-dimensional structural schematic diagram of the pulverized coal injection gun core of the vortex heating pulverized coal injection gun device used in an embodiment of the present invention is shown.

[0021] Figure 9 The diagram shows a front view of the multi-angle distributed mixer device used in an embodiment of the present invention.

[0022] Figure 10 A side view of the multi-angle distributed mixer device used in an embodiment of the present invention is shown.

[0023] Figure 11 It shows Figure 8 A schematic diagram of the cross-sectional structure along direction A.

[0024] Figure 12 It shows Figure 7 A schematic diagram of the cross-sectional structure along direction B.

[0025] Figure 13 A schematic diagram of the negative pressure flue gas furnace used in an embodiment of the present invention is shown.

[0026] Figure 14 A schematic diagram of the split-flow pyrolysis reactor used in an embodiment of the present invention is shown.

[0027] Figure 15 A cross-sectional view of the material heating distributor used in an embodiment of the present invention is shown.

[0028] Figure 16 A perspective view of the material heating distributor used in an embodiment of the present invention is shown.

[0029] Figure 17 This is a perspective view of the material heating distributor used in an embodiment of the present invention from another angle.

[0030] Figure 18 A cross-sectional view of the spiral pyrolysis reactor used in an embodiment of the present invention is shown.

[0031] Figure 19 A partial perspective view of the spiral pyrolysis reactor used in an embodiment of the present invention is shown.

[0032] Explanation of reference numerals in the attached figures

[0033] 1. Primary heat mixing unit; 2. Secondary heat mixing unit; 3. Steam supply unit; 4. High-temperature flue gas furnace;

[0034] P0 coal-water slurry feedstock; P1 atomized coal-water slurry feedstock; P G High-temperature steam; P2 First steam; P3 First gas mixture; P4 Steam; P5 Second gas mixture; P6 Product gas;

[0035] 10. Equipment for the water-based process of natural gas production; 101. Steam buffer tank; 102. Atomizer; 103. Coal slurry mixing device; 104. Coal slurry pump; 105. Buffer tank; 106. Gas storage device; 107. Product gas outlet flow meter; 108. Water source; 109. Softened water tank; 110. Sedimentation tank; 111. Heat exchanger feed water pump; 112. Water pump; 113. Booster pump; 114. Compressor; 115. Gas booster pump; 116. Heat exchanger inlet water regulating valve;

[0036] 200 Vortex heating coal injection lance device; 2001 Mixing channel; 2002 Atomized material channel; 2003 Heating steam channel; 2004 Branch channel; 2005 Coal injection lance shell; 2006 Coal injection lance core; 2007 Groove; 2008 First sealing part; 2009 Annular groove; 2010 First conical part; 2011 Second sealing part; 2012 Second conical part; 2013 Blind hole; 2014 Heating steam inlet;

[0037] 300-degree multi-angle distributed heat mixer device; 3001 heat mixing shell; 3002 heat mixing channel; 3003 heating pipe; 3004 heating channel; 3005 reducing connecting pipe; 3006 heating core; 3007 heating tank;

[0038] 400 Negative Pressure Flue Gas Furnace; 401 Furnace Body; 4011 Refractory Material Casting Layer; 4012 Refractory Material Masonry Layer; 4013 Thermal Insulation Material Layer; 4014 Metal Shell; 4015 Furnace Chamber; 402 Burner; 4021 Gas Outlet Pipe; 403 Negative Pressure Exhaust Fan; 404 High Temperature Flue Gas Heat Exchanger; 405 Low Temperature Flue Gas Heat Exchanger; 406 High Temperature Product Heat Exchanger; 407 Low Temperature Product Heat Exchanger; 408 Pressure Control Valve; 409 Pressure Control Tank;

[0039] 500 Diversion pyrolysis reactor; 501 Material heating distributor; 5011 Material distribution inlet; 5012 Material distribution outlet; 5013 Inner cylinder; 5014 Outer cylinder; 5015 Flue gas outlet; 5016 Flue gas duct; 5017 Material distribution channel; 5018 End plate; 5019 Flue gas inlet; 5020 V-groove; 5021 Connecting plate; 502 Spiral pyrolysis reactor; 5021 Material pyrolysis inlet; 5022 Material outlet; 5023 Inner wall; 5024 Outer wall; 5025 Annular bottom wall; 5026 Superheated fire channel; 5027 Spiral blade structure;

[0040] 600 water washing dust filter device; 700 gas-liquid separation device; 800 gas-solid separation device; 900 desulfurization device;

[0041] MI material inlet pipe; GE flue gas outlet pipe; PE product outlet pipe. Detailed Implementation

[0042] 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.

[0043] This invention provides a water-based process for producing natural gas. In an oxygen-isolated environment, atomized coal-water slurry feedstock is contacted with high-temperature steam at 800–1000°C. The system undergoes multi-stage mixing and heating to raise the temperature to 200–400°C, and then continues to raise the temperature to the temperature required for the pyrolysis reaction, thereby obtaining a product gas containing natural gas. The high-temperature steam serves as a pyrolysis agent, reactant, and auxiliary catalyst, and the product gas serves as an atomizing agent for the coal-water slurry feedstock.

[0044] The term "pyrolysis reaction" in this invention refers to the entire reaction process from coal-water slurry raw material and steam to the final product gas containing natural gas.

[0045] According to a preferred embodiment of the present invention, the temperature of the high-temperature steam is 900-1000°C and the pressure is 1.2-1.8 MPa.

[0046] In the method of this invention, the step of obtaining the product gas is carried out in a single heated reaction vessel. This means that for a single heated reaction vessel, the feed consists mainly of coal-water slurry and steam, and the output is product gas containing natural gas. All reactions occurring in the process (including high-temperature steam carbon pyrolysis, hydrogenation, oxidation, and a series of methanation reactions) take place in a closed space. That is, it is not necessary to use multiple reactors for the reaction of coal-water slurry and steam to produce methane. The meaning of "multiple reactors" is well-known to those skilled in the art; each reactor has its own independent inlet and outlet, as well as its own closed space. Furthermore, this invention does not require the separation of solid components within the system before the pyrolysis reaction; that is, there is no need to set up a step or equipment for separating solid components before the system produces a large amount of methane gas.

[0047] The reaction system of this invention does not require the addition of industrial-grade catalysts; that is, it is not necessary to add additional industrial-grade catalysts, but rather utilizes the catalytic components naturally present in coal. The term "industrial-grade catalyst" refers to various catalysts added in conventional coal-to-natural-gas processes. "Industrial-grade" does not mean that they have been commercialized or are available for sale, but rather that the catalyst has the potential for industrial application.

[0048] If the catalytic components in the coal-water slurry feedstock are found to be insufficient during the process, the process of the present invention does not exclude the option of adding an industrial catalyst. However, the added catalyst is only a supplement and its amount is much lower than the amount of catalyst added in the existing process.

[0049] According to a preferred embodiment of the present invention, the particle size of the coal powder in the coal-water slurry is 50-200 mesh.

[0050] According to the present invention, the coal-water slurry feedstock is contacted with high-temperature steam in an atomized state. The atomization can be achieved using a conventional atomizer in the art.

[0051] According to a preferred embodiment of the present invention, the step of multi-stage mixing and heating to 200-400°C includes: the atomized coal-water slurry raw material is contacted with high-temperature steam in a primary mixing device and heated to 100-150°C, and then contacted with high-temperature steam again in a secondary mixing device and heated to 200-400°C.

[0052] According to a preferred embodiment of the present invention, the primary mixing device is a vortex heating coal injection gun device, comprising:

[0053] The pulverized coal injection gun body has a mixing channel, a mist material channel and at least one heating steam channel inside. One end of the mixing channel is open. The heating steam channel is spiral-shaped and one end of the heating steam channel is connected to the other end of the mixing channel. One end of the mist material channel is connected to the heating steam channel through a branch channel. The axis of the branch channel forms an angle with the axis of the mist material channel.

[0054] According to a preferred embodiment of the present invention, the secondary heat mixing device is a multi-angle distributed heat mixer device, comprising:

[0055] The heat mixing shell is cylindrical, and a heat mixing channel is provided inside the heat mixing shell;

[0056] Multiple heating pipes are connected to the heat mixing channel. The multiple heating pipes are arranged sequentially at intervals along the axis of the heat mixing channel, and the multiple heating pipes are located at different circumferential angles on the radial cross section of the heat mixing channel.

[0057] According to the present invention, preferably, the temperature required for the pyrolysis reaction is 700–1000°C.

[0058] According to the present invention, preferably, the step of continuing to heat to the temperature required for the pyrolysis reaction is carried out in the heated reaction vessel, which is preferably a high-temperature flue gas furnace.

[0059] According to the present invention, preferably, the system temperature in the heating reaction vessel is controlled at 1150-1250°C and the system pressure is controlled at 0.5-1.0 MPa.

[0060] According to one embodiment of the present invention, the process method of the present invention is as follows: Figure 1 The procedure is performed on the apparatus shown.

[0061] In an oxygen-isolated environment, atomized coal-water slurry feedstock P1 reacts with high-temperature steam P at 800–1000℃.G After contact, the system undergoes multi-stage mixing and heating to 200-400℃, and then enters the high-temperature flue gas furnace 4 to continue heating to the temperature required for the pyrolysis reaction. The reaction yields product gas P6 containing natural gas. The high-temperature steam serves as a pyrolysis agent, reactant, and auxiliary catalyst, while the product gas P6 serves as an atomizing agent for the coal-water slurry feedstock.

[0062] According to a preferred embodiment of the present invention, the process method of the present invention is as follows: Figure 2 The procedure is performed on the apparatus shown.

[0063] The device includes a primary mixing unit 1, a secondary mixing unit 2, and a high-temperature flue gas furnace 4 connected in sequence. The primary mixing unit 1 is connected to an atomized coal-water slurry feedstock supply device and a steam supply device 3, and is used to heat the atomized coal-water slurry feedstock P1 by contacting it with the first steam P2 to obtain a first coal gas mixture P3. The secondary mixing unit 2 is connected to the steam supply device 3, and is used to heat the first coal gas mixture P3 by contacting it with the second steam P4 to obtain a second coal gas mixture P5. The high-temperature flue gas furnace 4 is used for further heating and reaction of the second coal gas mixture P5 to obtain product gas P6, and part of the product gas P6 is used as an atomizing agent for the coal-water slurry feedstock P0.

[0064] According to a preferred embodiment of the present invention, the high-temperature flue gas furnace 4 is a negative pressure flue gas furnace, and the negative pressure flue gas furnace includes:

[0065] The furnace body is provided with a material inlet pipe, a flue gas outlet pipe, and a product outlet pipe that penetrate the furnace wall;

[0066] The diversion pyrolysis reactor includes a material heating distributor and a spiral pyrolysis reactor. The material heating distributor is located inside the furnace body, and its material distribution inlet is connected to the material inlet pipe. It is used to heat the material and distribute it to the spiral pyrolysis reactor for pyrolysis reaction. The spiral pyrolysis reactor is located inside the furnace body, and its material pyrolysis inlet and material outlet are respectively connected to the material distribution outlet of the material heating distributor and the product outlet pipe.

[0067] A burner, wherein the burner's outlet pipe passes through the furnace wall and communicates with the furnace chamber, for supplying high-temperature flue gas into the furnace chamber; and

[0068] The negative pressure induced draft control system is used to control the temperature of the furnace and the temperature of the flue gas discharged from the flue gas outlet pipe.

[0069] Furthermore, the negative pressure induced draft control system includes a controller, a negative pressure induced draft fan, a furnace temperature sensor, and an outlet flue gas temperature sensor. The negative pressure induced draft fan is connected to the flue gas outlet pipe, and the furnace temperature sensor and the outlet flue gas temperature sensor are used to measure the furnace temperature and the flue gas temperature, respectively.

[0070] Furthermore, the controller controls the rotation speed of the negative pressure induced draft fan and the power of the burner based on the measurement results of the furnace temperature sensor and the flue gas temperature sensor, so as to keep the furnace temperature T1 within a certain temperature range and the flue gas temperature T2 within a certain temperature range.

[0071] Furthermore, the negative pressure induced draft fan is located at the outlet end of the low-temperature flue gas heat exchanger.

[0072] Furthermore, the negative pressure induced draft control system also includes a flue gas final emission temperature sensor, which is located between the negative pressure induced draft fan and the outlet end of the low-temperature flue gas heat exchanger, and is used to measure the final emission temperature of the flue gas.

[0073] Furthermore, the controller controls the cooling water flow rate of the low-temperature flue gas heat exchanger based on the measurement results of the flue gas final emission temperature sensor, so as to keep the final emission temperature T4 of the flue gas within a certain temperature range.

[0074] According to the present invention, in order to better utilize heat, the high-temperature steam is preferably obtained by sequentially exchanging heat between low-temperature water and product gas, and high-temperature flue gas generated by a high-temperature flue gas generator.

[0075] Accordingly, the high-temperature flue gas furnace also includes a flue gas heat exchanger and a product heat exchanger. The flue gas heat exchanger is located at the outlet end of the flue gas outlet pipe, and the product heat exchanger is located at the outlet end of the product outlet pipe. The flue gas heat exchanger includes a high-temperature flue gas heat exchanger and a low-temperature flue gas heat exchanger connected in series, and the product heat exchanger includes a high-temperature product heat exchanger and a low-temperature product heat exchanger connected in series.

[0076] This invention preferably utilizes high-temperature flue gas and product heat energy to produce high-temperature steam. Compared with the oxygenated or aerobic pyrolysis process in traditional coal-to-natural gas production, this invention improves thermal efficiency by more than 50% through the repeated utilization of heat energy, directly reducing production costs.

[0077] The high-temperature steam described in this invention can be provided by a steam supply device 3, which includes a steam buffer tank. The steam buffer tank is connected to a water source in sequence through the high-temperature flue gas heat exchanger, the high-temperature product heat exchanger, and the low-temperature product heat exchanger.

[0078] According to the present invention, the method further includes purifying the product gas to obtain clean product gas; the purification includes sequentially performing dust filtration, water washing, gas-liquid separation, gas-solid separation and desulfurization on the product gas.

[0079] The above steps can be carried out in sequence in the water washing dust filter device, gas-liquid separation device, gas-solid separation device, desulfurization device and buffer tank connected to the low-temperature product heat exchanger; the outlet of the buffer tank is connected to the gas storage device, the burner and the user pipeline respectively, so as to store the product gas in the gas storage device and supply it to the burner and the user; the atomized coal-water slurry raw material supply device includes a coal slurry stirring device, a coal slurry pump and an atomizer, the coal slurry pump is connected to the coal slurry stirring device, and the atomizer is connected to the gas storage device and the coal slurry pump respectively, so as to atomize the coal slurry supplied by the coal slurry pump by the product gas from the gas storage device to obtain the atomized coal-water slurry raw material.

[0080] According to the present invention, preferably, the water-washing dust filter device comprises:

[0081] A water seal dust filter assembly, comprising a water seal tank, wherein the water seal tank is provided with a first drain outlet, a first dust-laden gas inlet, a first spray outlet and a first air outlet from bottom to top;

[0082] A water-washing filter assembly includes a water-washing tank, which is provided with a second drain outlet, a second dust-laden gas inlet, a second air outlet, and a second spray outlet from bottom to top. A flow-blocking plate is provided inside the water-washing tank, which is positioned above the second dust-laden gas inlet and is connected to the first air outlet.

[0083] According to a preferred embodiment of the present invention, the atomizing agent used to atomize the raw coal is the purified product gas; the fuel for the high-temperature flue gas furnace is the purified product gas.

[0084] In the method of the present invention, by contacting the coal-water slurry raw material with steam and by heat exchange and heating in the reactor, the elemental metals and elemental non-metals in the coal-water slurry raw material have enhanced hydrogenation, oxidation and catalytic efficiency under the action of steam and high temperature. While pyrolyzing carbon elements, a series of methanation reactions are carried out to achieve one-step efficient production of natural gas.

[0085] Example 1

[0086] This embodiment illustrates a water-based process for producing natural gas according to the present invention. It employs methods such as... Figure 1 The equipment shown is for a water-based process for producing natural gas.

[0087] In an oxygen-isolated environment, the atomized coal-water slurry feedstock P1 reacts with high-temperature steam P at 800–1000℃ and 1.2–1.8 MPa. G After contact, the system undergoes multi-stage mixing and heating to 200–400°C, then enters a high-temperature flue gas furnace 4 for further heating to 700–1000°C, reacting to obtain natural gas-containing product gas P6. The high-temperature steam P... G As a pyrolysis agent, reactant, and auxiliary catalyst, the product gas P6 serves as an atomizing agent for coal-water slurry feedstock. No additional industrial catalyst is added to the reaction system, and the solid components within the system are not separated before the pyrolysis reaction.

[0088] Example 2

[0089] This embodiment illustrates a water-based process for producing natural gas according to the present invention. It employs methods such as... Figure 2 The equipment shown is for a water-based process for producing natural gas.

[0090] The apparatus comprises a primary mixing unit 1, a secondary mixing unit 2, and a high-temperature flue gas furnace 4 connected in sequence. The primary mixing unit 1 is connected to an atomized coal-water slurry feedstock supply device and a steam supply device 3, used to contact the atomized coal-water slurry feedstock P1 with first steam P2 to raise its temperature and obtain a first gas mixture P3 at 100–150°C. The secondary mixing unit 2 is connected to the steam supply device 3, used to contact the first gas mixture P3 with second steam P4 to raise its temperature and obtain a second gas mixture P5 at 200–400°C. The high-temperature flue gas furnace 4 is used to further heat the second gas mixture P5 to 700–1000°C and react it to obtain product gas P6, a portion of which is used as an atomizing agent for the coal-water slurry feedstock P0. The first steam P2 and the second steam P4 are high-temperature steam at 900–1000°C and a pressure of 1.2–1.8 MPa. No additional industrial catalyst is added to the reaction system, and the solid components within the system are not separated before the pyrolysis reaction.

[0091] Example 3

[0092] This embodiment illustrates a water-based process for producing natural gas according to the present invention. It employs methods such as... Figure 3 The equipment shown is for a water-based process for producing natural gas.

[0093] like Figure 3As shown, the equipment 10 for the water-based natural gas production process includes a primary mixing unit, a secondary mixing unit, and a high-temperature flue gas furnace connected in sequence. The primary mixing unit is connected to an atomized coal-water slurry feedstock supply device and a steam supply device, used to contact the atomized coal-water slurry feedstock with first steam to raise its temperature and obtain a first coal gas mixture. The secondary mixing unit is connected to the steam supply device, used to contact the first coal gas mixture with second steam to raise its temperature and obtain a second coal gas mixture. The high-temperature flue gas furnace is used to pyrolyze the second coal gas mixture to obtain product gas.

[0094] The water-based process for producing natural gas includes: in an oxygen-isolated environment, atomized coal-water slurry feedstock is contacted with high-temperature steam at 800–1000°C; the system undergoes two-stage mixing and heating to raise the temperature to 200–400°C, and then continues to raise the temperature to the temperature required for the pyrolysis reaction, thereby obtaining product gas containing natural gas; the high-temperature steam serves as a pyrolysis agent, reactant, and auxiliary catalyst, and the product gas serves as an atomizing agent for the coal-water slurry feedstock.

[0095] The steps of heating the two-stage mixed heat source to 200–400°C and then continuing to heat to the temperature required for the pyrolysis reaction include:

[0096] The first step involves using a primary mixing device to bring the coal-water slurry raw material into contact with the first steam, and then mixing and heating it to 100-150°C.

[0097] The second step involves using a two-stage mixing device to bring the mixture obtained in the first step into contact with the second water vapor, and then heating the mixture to 200–400°C.

[0098] The third step is to heat the mixture obtained in the second step to 700-1000°C in a high-temperature flue gas furnace.

[0099] The product gas obtained from the water-based natural gas production process equipment 10 sequentially passes through a product heat exchanger, a water-washing dust filter device 600, a gas-liquid separator 700, a gas-solid separator 800, a desulfurization device 900, and a buffer tank 105 for heat exchange, water washing dust filtration, gas-liquid separation, gas-solid separation, desulfurization, and buffering. The final product can be stored in a gas storage device 106, directly supplied to user pipelines, or supplied to a high-temperature flue gas furnace as fuel. Specifically, the inlet of the product gas into the burner is sequentially equipped with a first manual ball valve, a burner primary pressure regulator, a second manual ball valve, a burner secondary pressure stabilizer, and a third manual ball valve to regulate the pressure of the product gas entering the burner.

[0100] The gas-liquid separator 700, gas-solid separator 800, and desulfurization unit 900 are all connected to the sewage discharge pipeline via electric control valves, allowing the generated wastewater to be discharged. A check valve and a product gas outlet flow meter 107 are also installed between the desulfurization unit 900 and the buffer tank 105. The outlet of the buffer tank 105 is equipped with a pressure control valve and a pressure regulator to adjust the pressure in the buffer tank. Under normal circumstances, the pressure inside the buffer tank 105 is maintained at approximately 0.45 MPa. The gas storage device 106 can be a gas storage cylinder, with a compressor 114 installed at the inlet to compress the product gas. Under normal circumstances, the pressure inside the gas storage cylinder is controlled at approximately 1.5 MPa. In addition, a gas-liquid separation gas recovery device 7000 is also provided to recover the product gas contained in the liquid discharged from the water washing and dust removal device 600.

[0101] The coal-water slurry feedstock comes into contact with the first steam in an atomized state. Therefore, the atomized coal-water slurry feedstock supply device includes a coal slurry mixing device 103, a coal slurry pump 104, and an atomizer 102. The coal slurry pump 104 is connected to the coal slurry mixing device 103 and supplies the coal slurry to the atomizer 102. The atomizer 102 is connected to both a gas storage device 106 and the coal slurry pump 104, and atomizes the coal slurry supplied by the coal slurry pump 104 using product gas from the gas storage device 106, thus obtaining the atomized coal-water slurry feedstock. Using product gas to atomize the coal slurry avoids the introduction of impurities.

[0102] The particle size of the coal powder in the coal-water slurry raw material is 50-200 mesh.

[0103] In this embodiment, an electric regulating valve and a coal slurry flow meter are also provided between the coal slurry pump 104 and the atomizer 102 to control the flow rate of coal slurry pumped by the coal slurry pump 104. An atomizing gas regulating valve and an atomizing gas flow meter are provided between the atomizer 102 and the gas storage device 106 to control the flow rate of water vapor entering the atomizer 102.

[0104] The atomized coal-water slurry feedstock is contacted, mixed, and heated by steam supplied by a primary mixing device, a secondary mixing device, and a steam supply device (i.e., steam buffer tank 101). Preferably, a check valve and a manual ball valve are provided between the atomizer 102 and the primary mixing device to control the supply of the coal-water slurry feedstock. The primary mixing device includes a vortex-heated coal injection gun device 200, and the secondary mixing device includes a multi-angle distributed mixer device 300.

[0105] Vortex heating coal injection gun device

[0106] like Figures 4 to 8 As shown, the vortex heating coal injection gun device 200 includes:

[0107] The pulverized coal injection gun body has a mixing channel 2001, a mist material channel 2002 and at least one heating steam channel 2003 inside. One end of the mixing channel 2001 is open. The heating steam channel 2003 is spiral and one end of the heating steam channel 2003 is connected to the other end of the mixing channel 2001. One end of the mist material channel 2002 is connected to one end of the heating steam channel 2003 through a branch channel 2004. The axis of the branch channel 2004 forms an angle with the axis of the mist material channel 2002.

[0108] Specifically, the atomized material channel 2002 is used to transport the atomized material, and the heating steam channel 2003 is used to transport high-temperature steam. After the atomized material enters the pulverized coal injection gun body, it passes through the atomized material channel 2002 and the branch channel 2004 in sequence. After the high-temperature steam enters the pulverized coal injection gun body, it flows in a spiral trajectory along the spiral heating steam channel 2003. The atomized material and the high-temperature steam mix at the intersection of the branch channel 2004 and the heating steam channel 2003. Due to the different flow directions of the two, the atomized material and the high-temperature steam collide, heat and mix at the intersection, and the high-temperature steam heats the atomized material to form a mixed-heat material. The mixed-heat material can enter the mixing channel 2001, which is set at one end inside the pulverized coal injection gun body. The mixed-heat material is sprayed out through the mixing channel 2001.

[0109] In one example, the high-temperature steam is water vapor at 800–1000°C and 1.2–1.8 MPa, and the temperature of the mixed material after being heated by the high-temperature steam is 100–150°C.

[0110] Optionally, the other end of the mist material channel 2002 is open, and the other end of the mist material channel 2002 is used to connect to the material atomization structure.

[0111] Furthermore, the pressure of the high-temperature steam and the atomized gas enables the mixed heat material to be ejected from the mixing channel 2001.

[0112] Optionally, the other end of the heating steam passage 2003 is open and is used to connect a steam supply device.

[0113] Specifically, the steam supply device can be a steam buffer tank 101, which provides steam at 800-1000℃ and 1.2-1.8MPa to the aforementioned vortex heating coal injection gun.

[0114] Optionally, the pulverized coal injection gun body includes a pulverized coal injection gun housing 2005 and a pulverized coal injection gun core 2006. The pulverized coal injection gun housing 2005 is cylindrical, and the pulverized coal injection gun core 2006 is inserted inside the pulverized coal injection gun housing 2005. The atomized material channel 2002 is disposed inside the pulverized coal injection gun core 2006. At least one spiral groove 2007 is provided on the outer periphery of the pulverized coal injection gun core 2006. Each groove 2007 forms a heating steam channel 2003 inside the pulverized coal injection gun housing 2005.

[0115] Specifically, the coal injection gun housing 2005 and the coal injection gun core 2006 can be manufactured separately and then assembled, simplifying the manufacturing process and improving manufacturing precision; the spiral groove 2007 on the outer periphery of the coal injection gun core 2006 forms a spiral heating steam channel 2003 between the coal injection gun core 2006 and the coal injection gun housing 2005, and the number of heating steam channels 2003 can be set as needed.

[0116] In one example, the pulverized coal injection gun core 2006 is cylindrical, the pulverized coal injection gun housing 2005 is cylindrical, and three slots 2007 are evenly arranged on the outer periphery of the pulverized coal injection gun core 2006 along the circumferential direction of the pulverized coal injection gun core 2006. The mist material channel 2002 is arranged at the center of the pulverized coal injection gun core 2006 along the axis of the pulverized coal injection gun core 2006. Three branch pipes are provided, one end of which is connected to the side wall of the mist material channel 2002, and the other end of which is connected to the bottom of the slot 2007.

[0117] Furthermore, the intersection of the branch pipeline and the tank 2007 is close to the other end of the mixing channel 2001, ensuring that the atomized material in the branch pipeline mixes with the high-temperature steam in the tank 2007 and immediately enters the mixing channel 2001 and is sprayed out through the mixing channel 2001.

[0118] Optionally, one end of the pulverized coal injection gun core 2006 is provided with an annular first sealing part 2008, which is sealed to one end of the pulverized coal injection gun housing 2005.

[0119] Specifically, the end face or outer periphery of the first sealing part 2008 can be sealed and connected to one end of the coal injection gun housing 2005, and the other end of the mist material channel 2002 inside the coal injection gun core 2006 is open on the end face near the first sealing part 2008.

[0120] Optionally, an annular groove 2009 is provided on the outer periphery of the end of the pulverized coal injection gun core 2006 near the first sealing part 2008, and a groove 2007 is provided on the outer periphery of the end of the pulverized coal injection gun core 2006 away from the first sealing part 2008, with one end of the groove 2007 communicating with the annular groove 2009.

[0121] Specifically, the annular groove 2009 is set inside the pulverized coal gun housing 2005 to form a heating steam inlet groove, which is connected to the heating steam channel 2003 and is used to introduce high-temperature steam into the heating steam channel 2003.

[0122] Optionally, a first conical part 2010 is provided on the end face of the coal injection gun core 2006 away from the first sealing part 2008. The first conical part 2010 and the other end of the coal injection gun shell 2005 form a mixing channel 2001 with a gradually expanding cross section. The other end of the groove 2007 is connected to the mixing channel 2001.

[0123] Specifically, the cross-sectional diameter of the end of the first conical part 2010 near the pulverized coal injection gun core 2006 is larger than the cross-sectional diameter of the end away from the pulverized coal injection gun core 2006. The setting of the first conical part 2010 makes the mixing channel 2001 a ring channel with a gradually expanding cross-section. The mixed heat material entering the mixing channel 2001 through the other end of the mixing channel 2001 is sprayed out after passing through the gradually expanding cross-section mixing channel 2001, which plays a role in reducing pressure and increasing speed for the mixed heat material.

[0124] Optionally, the mist material channel 2002 is open at one end near the first blocking part 2008, and a second blocking part 2011 is provided inside the end of the mist material channel 2002 away from the first blocking part 2008. A second conical part 2012 is provided at one end of the second blocking part 2011, and the tip of the second conical part 2012 is located at the junction of the mist material channel 2002 and the branch channel 2004.

[0125] Specifically, the tip of the second cone-shaped part 2012 is located at the junction of the mist material channel 2002 and the branch channel 2004. Since the axis of the branch channel 2004 forms an angle with the axis of the mist material channel 2002, the atomized material in the mist material channel 2002 needs to enter each branch channel 2004. The setting of the second cone-shaped part 2012 can make the amount of atomized material entering each branch channel 2004 more uniform.

[0126] Optionally, a blind hole 2013 is provided at one end of the pulverized coal injection gun core 2006, and the blind hole 2013 is connected to the mist material channel 2002.

[0127] Specifically, the blind hole 2013 is used to connect the outlet pipeline of the material atomization structure.

[0128] Optionally, a heating steam inlet 2014 is provided on the outer shell 2005 of the pulverized coal injection gun, and the heating steam inlet 2014 is connected to the annular groove 2009.

[0129] Specifically, the heating steam inlet 2014 is located on the coal injection gun housing 2005. The angle between the axis of the heating steam inlet 2014 and the axis of the coal injection gun housing 2005 can be set as needed. In one example, the angle between the axis of the heating steam inlet 2014 and the axis of the coal injection gun housing 2005 is 90°. The heating steam inlet 2014 is connected to the heating steam inlet groove formed by the annular groove 2009.

[0130] In this embodiment, coal-water slurry and product gas are simultaneously input into atomizer 102. The product gas atomizes the coal-water slurry to form atomized material. After entering the coal injection gun body, the atomized material passes through the atomized material channel 2002 and the branch channel 2004 in sequence. After entering the coal injection gun body, high-temperature steam flows along the spiral heating steam channel 2003 in a spiral trajectory. The atomized material and high-temperature steam mix at the intersection of the branch channel 2004 and the heating steam channel 2003. Due to the different flow directions, the atomized material and high-temperature steam collide, heat, and mix at this intersection, and the high-temperature steam heats the atomized material to form a mixed-heat material at 100-150°C. The mixed-heat material can enter the mixing channel 2001, which is located at one end inside the coal injection gun body. The mixed-heat material is sprayed out through the mixing channel 2001 and can enter the equipment of the next process.

[0131] Multi-angle distributed heat exchanger device

[0132] Figure 9 and Figure 10 The front view and side view of the multi-angle distributed mixer device according to an embodiment of the present invention are shown respectively. Figure 11 It shows Figure 10 A schematic diagram of the cross-sectional structure along direction A. Figure 12 It shows Figure 9 A schematic diagram of the cross-sectional structure along direction B. (See attached diagram.) Figures 9 to 12 As shown, the multi-angle distributed heat exchanger device 300 includes:

[0133] The heat mixing shell 3001 is cylindrical, and a heat mixing channel 3002 is provided inside the heat mixing shell 3001;

[0134] Multiple heating pipes 3003 are connected to the heat mixing channel 3002. The multiple heating pipes 3003 are arranged sequentially at intervals along the axis of the heat mixing channel 3002. The multiple heating pipes 3003 are located at different circumferential angles on the radial cross section of the heat mixing channel 3002.

[0135] Specifically, the mixing channel 3002 can be used to introduce mixing materials. High-temperature steam is introduced into the mixing channel 3002 through multiple heating pipes 3003. The high-temperature steam mixes with the mixing materials, thereby raising the temperature of the mixing materials and achieving the heating effect. Multiple heating pipes 3003 are arranged at intervals along the axis of the mixing channel 3002 and at different circumferential angles on the radial cross section of the mixing channel 3002. This forms a multi-stage, multi-angle high-temperature steam mixing in the axial direction of the mixing channel 3002, which improves the mixing and collision degree between the high-temperature steam and the mixing materials, thereby achieving the mixing and heating of the mixing materials.

[0136] Optionally, a spiral heating channel 3004 is provided inside the heating pipe 3003.

[0137] Specifically, the spiral heating channel 3004 can guide the high-temperature steam to enter the mixing channel 3002 under the spiral guidance of the heating channel 3004, thereby increasing the collision and mixing degree between the heating steam and the mixing material in the mixing channel 3002, and thus improving the mixing effect.

[0138] Optionally, one end of the mixing shell 3001 is the mixing material inlet, and the other end of the mixing shell 3001 is the mixing material outlet.

[0139] Specifically, both ends of the mixing channel 3002 are open. The mixing material flows in from the mixing material inlet, flows in the mixing channel 3002, and after being mixed with high-temperature steam, it flows out from the mixing material outlet.

[0140] Optionally, a reducing pipe 3005 is connected to the outlet of the mixed heat material.

[0141] Specifically, the variable diameter connecting pipe 3005 facilitates the connection between the outlet of the mixed heat material and the material inlet of the equipment in the next process.

[0142] Optionally, a heating core 3006 is provided inside the heating pipe 3003, and a spiral heating groove 3007 is provided on the outer periphery of the heating core 3006. The heating groove 3007 forms a heating channel 3004 inside the heating pipe 3003.

[0143] Specifically, the shape of the heating core 3006 is adapted to the internal shape of the heating pipe 3003 and is connected to the inner wall of the heating pipe 3003. The heating core 3006 can be columnar or conical. The heating groove 3007 is formed on the outer periphery of the heating core 3006. After the heating core 3006 is connected to the inner wall of the heating pipe 3003, a spiral heating channel 3004 is formed between the heating groove 3007 and the inner wall of the heating pipe 3003.

[0144] Furthermore, the heating core 3006 can be manufactured and processed separately. After the heating core 3006 is manufactured, it can be assembled with the heating pipe 3003. This can reduce the manufacturing difficulty of the heating pipe 3003 with the internal spiral heating channel 3004 and reduce the manufacturing cost.

[0145] Optionally, the heating pipe 3003 includes a straight pipe section and a reducing pipe section. The straight pipe section is connected to the heat mixing shell 3001, and the heating core 3006 is disposed inside the reducing pipe section.

[0146] Specifically, the straight pipe section is connected to the mixing shell 3001. In one example, the axis of the straight pipe section is perpendicular to the axis of the mixing channel 3002. The variable diameter pipe component facilitates the connection between the heating pipe 3003 and the steam supply device.

[0147] Optionally, heating pipe 3003 is used to connect to a steam supply device.

[0148] Specifically, the steam supply device can be a steam buffer tank 101, which provides steam at 800-1000°C to the aforementioned multi-angle distributed mixer device.

[0149] Optionally, a plurality of heating pipe 3003 connection holes are provided on the outer wall of the heating housing 3001, and the heating pipe 3003 is connected to the heating pipe 3003 connection holes.

[0150] Specifically, the heating pipe 3003 can be welded to the mixing shell 3001, so that the heating pipe 3003 is connected to the heating pipe 3003 connection hole.

[0151] Optionally, the connection holes of multiple heating pipes 3003 are equally spaced along the axial direction of the mixing channel 3002.

[0152] Specifically, multiple heating pipes 3003, which are equally spaced along the axial direction of the mixing channel 3002, form a multi-stage high-temperature steam mixing process in the flow path of the mixing material, thereby improving the mixing effect.

[0153] Optionally, the heating pipe 3003 connection hole is provided with three holes, which are evenly distributed along the circumference of the mixing shell 3001.

[0154] Specifically, the three heating pipes 3003 are sequentially designated as the first heating pipe 3003, the second heating pipe 3003, and the third heating pipe 3003 along the flow path of the mixed heat material. If the connection hole of the first heating pipe 3003 is located at a 0° circumferential angle in the circumferential direction of the mixing shell 3001, then the connection hole of the second heating pipe 3003 is located at a 120° circumferential angle in the circumferential direction of the mixing shell 3001, and the connection hole of the third heating pipe 3003 is located at a 240° circumferential angle in the circumferential direction of the mixing shell 3001. The multiple heating pipes 3003 are located at different circumferential angles on the radial cross-section of the mixing channel 3002, allowing the heating steam to enter the mixing channel 3002 from different circumferential angles on the radial cross-section of the mixing channel 3002, thereby achieving multi-angle steam inlet mixing and improving the mixing effect.

[0155] When using a multi-angle distributed mixer device, taking its application in a primary natural gas production process as an example: the mixing material inlet is connected to the mixing material outlet of the vortex heating coal injection gun device in the previous process of the multi-angle distributed mixer device. The vortex heating coal injection gun device can output mixing material at 100-150°C. After the mixing material enters the mixing channel 3002, high-temperature steam is introduced into the mixing channel 3002 through the heating pipe 3003 connected to the steam supply device. After entering the mixing channel 3002, the high-temperature steam collides and mixes with the mixing material, and performs high-temperature steam mixing and heating on the mixing material, so that the mixing material at 100-150°C is heated to 200-360°C, and then transported to the equipment in the next process through the reducing connecting pipe 3005.

[0156] Negative pressure flue gas furnace

[0157] In this embodiment, the high-temperature flue gas furnace is a negative pressure flue gas furnace. Figure 13 A schematic diagram of a negative pressure flue gas furnace according to an embodiment of the present invention is shown. Figure 13 As shown, the negative pressure flue gas furnace 400 includes:

[0158] Furnace body 401, the furnace body is equipped with a material inlet pipe MI, a flue gas outlet pipe GE and a product outlet pipe PE that penetrate through the furnace wall;

[0159] The diversion pyrolysis reactor 500 includes a material heating distributor 501 and a spiral pyrolysis reactor 502. The material heating distributor 501 is located inside the furnace body 401. The material distribution inlet of the material heating distributor 501 is connected to the material inlet pipe MI and is used to heat the material and distribute it to the spiral pyrolysis reactor 502 for pyrolysis reaction. The spiral pyrolysis reactor 502 is located inside the furnace body 401. The material pyrolysis inlet 5021 and the material outlet 5022 of the spiral pyrolysis reactor 502 are respectively connected to the material distribution outlet 5012 and the product outlet pipe PE of the material heating distributor 501.

[0160] Burner 402, with its outlet pipe 4021 passing through the furnace wall and connecting to the furnace chamber 4015, is used to supply high-temperature flue gas into the furnace chamber; and

[0161] The negative pressure induced draft control system is used to control the temperature of the furnace and the temperature of the flue gas discharged from the flue gas outlet pipe.

[0162] When the negative pressure flue gas furnace is operating, the burner operates, supplying high-temperature flue gas into the furnace through the exhaust pipe. The mixed-heat material enters the material heating distributor through the material inlet pipe, where it is heated and distributed to the spiral pyrolysis reactor, where it undergoes pyrolysis. The product obtained from the reaction is discharged through the product outlet pipe for the next process step; the flue gas is discharged through the flue gas outlet pipe. The negative pressure induced draft control system is used to control the temperature of the furnace and the temperature of the flue gas discharged through the flue gas outlet pipe, ensuring the normal operation of the reaction.

[0163] In this embodiment, the furnace body 401 is made of refractory material, and the outer wall of the furnace body 401 is provided with a thermal insulation material layer, which is covered by a metal outer shell 4014. Specifically, the furnace body 401 is constructed by casting and / or masonry of refractory material. In this embodiment, the inner layer of the furnace body is a refractory material masonry layer, and the outer layer is a refractory material casting layer. The thermal insulation material layer includes a thermal insulation coating layer and a thermal insulation cotton layer. By setting the thermal insulation material layer, the thermal insulation effect of the furnace body can be enhanced, and energy can be saved.

[0164] The furnace wall includes a top wall, a bottom wall, a front wall, a rear wall, and a pair of side walls. The material inlet pipe MI and the flue gas outlet pipe GE pass through the front wall, and the product outlet pipe PE passes through the bottom wall and is close to the rear wall. The burner 402 is located in the rear section of the furnace body, and its gas outlet pipe passes through the rear wall and connects to the furnace chamber to supply high-temperature flue gas into the furnace chamber.

[0165] The negative pressure flue gas furnace has a horizontal structure, in which the material heating distributor 501, the spiral pyrolysis reactor 502, and the burner's outlet pipe 4021 are arranged coaxially in the horizontal direction, which saves space and is easier to manufacture. Gaps are provided between the material heating distributor 501 and the spiral pyrolysis reactor 502 and the furnace wall of the furnace body 401, and these gaps are advantageously designed to facilitate the flow of high-temperature flue gas.

[0166] Separation pyrolysis reactor

[0167] Figure 14 A schematic diagram of a split-flow pyrolysis reactor according to an embodiment of the present invention is shown. Figure 14 As shown, the diversion pyrolysis reactor 500 includes a material heating distributor 501 and a spiral pyrolysis reactor 502 that are coaxially arranged and interconnected. The material heating distributor 501 is used to heat the material and distribute the material to the spiral pyrolysis reactor 502 for pyrolysis reaction.

[0168] During the reaction, the material is injected into the material heating distributor 501, where it is heated to 350–450°C. The heated material is then distributed to the spiral pyrolysis reactor 502, where it is reheated for pyrolysis. The spiral pyrolysis reactor 502 has a spiral-shaped pyrolysis channel, which extends the pyrolysis reaction path and ensures complete pyrolysis. The material that has completed the pyrolysis reaction is discharged from the spiral pyrolysis reactor for the next process step. No additional catalyst is added to the reaction system.

[0169] Figure 15 , Figure 16 and Figure 17 Cross-sectional and perspective views of a material heating distributor according to an embodiment of the present invention are shown respectively. Figure 18 and Figure 19 Cross-sectional view and partial perspective view of a spiral pyrolysis reactor according to an embodiment of the present invention are shown respectively.

[0170] like Figures 15 to 19 As shown, the material heating distributor 501 is provided with a material distribution inlet 5011 and a material distribution outlet 5012, and the spiral pyrolysis reactor 502 is provided with a material pyrolysis inlet 5021 and a material outlet 5022.

[0171] The material distribution inlet 5011 of the material heating distributor 501 is used to connect to the material inlet pipe, the material pyrolysis inlet 5021 is connected to the material distribution outlet 5012 of the material heating distributor 501, and the material outlet 5022 of the spiral pyrolysis reactor 502 is used to connect to the product outlet pipe.

[0172] During the reaction, the material enters the material heating distributor 501 through the material inlet pipe via the material distribution inlet 5011. After being heated, it enters the spiral pyrolysis reactor 502 through the material distribution outlet 5012 via the material pyrolysis inlet 5021. It is heated again in the spiral pyrolysis reactor 502 and after the pyrolysis reaction occurs, it is discharged from the product outlet pipe through the material outlet 5022.

[0173] In this embodiment, the material heating distributor 501 includes an inner cylinder 5013 and an outer cylinder 5014 sleeved outside the inner cylinder. A material distribution inlet 5011 is located at the front end of the outer cylinder 5014, and a flue gas outlet 5015 is provided on the side wall of the outer cylinder. The front end of the inner cylinder 5013 is closed, and a flue gas inlet 5019 is provided at the rear end. The flue gas outlet 5015 of the outer cylinder is connected to the interior of the inner cylinder 5013 via a flue gas pipe 5016, allowing the flue gas entering the inner cylinder through the flue gas inlet to be discharged sequentially through the flue gas pipe and the flue gas outlet. A material distribution channel 5017 is formed between the inner and outer cylinders. The front end of the material distribution channel 5017 is connected to the material distribution inlet 5011, and the rear end is provided with a material distribution outlet 5012.

[0174] During the reaction, both the material heating distributor 501 and the spiral pyrolysis reactor 502 are located inside the flue gas furnace. A portion of the high-temperature flue gas flows through the outer side of the outer cylinder, heating the material in the material distribution channel 5017 from the outside. Another portion of the high-temperature flue gas enters the inner cylinder 5013 through the flue gas inlet 5019, heating the material in the material distribution channel 5017 from the inside, and then exits through the flue gas pipe 5016 and the flue gas outlet 5015. The material, heated by the high-temperature flue gas, exits through the material distribution outlet 5012 and enters the spiral pyrolysis reactor 502. This method ensures that the material in the material distribution channel 5017 is fully heated from both the inside and outside, improving heating efficiency.

[0175] In this embodiment, the outer cylinder 5014 includes a conical first front end and a cylindrical first rear end. A material distribution inlet 5011 is located at the head of the first front end, and a flue gas outlet 5015 is located on the side wall of the first rear end. The inner cylinder 5013 includes a second front end, a second rear end, and an end plate 5018 connected in sequence. The second front end is conical, the second rear end is cylindrical, and the end plate 5018 is annular and located on the outer periphery of the end of the second rear end. A flue gas inlet 5019 is located at the center of the end plate 5018. A V-groove 5020 is provided on the outer periphery of the end plate 5018, and the V-groove 5020 communicates with the material distribution channel 5017, with the communicating portion being the material distribution outlet 5012.

[0176] The material distribution outlet 5012 is formed by the connection between the V-groove 5020 and the material distribution channel 5017. In practical applications, the cross-sectional area of ​​the material distribution outlet 5012 can be adjusted by adjusting the depth of the V-groove according to the design flow rate, thereby changing the material flow rate.

[0177] There are multiple flue gas outlets 5015 and multiple flue gas ducts 5016, which are evenly distributed along the circumference of the outer cylinder 5014, and the position of each flue gas outlet 5015 corresponds to the position of one flue gas duct 5016. Correspondingly, there are also multiple V-grooves 5020, which are evenly distributed along the outer circumference of the end plate 5018, and the V-grooves 5020 and flue gas outlets 5015 are alternately arranged along the circumference of the end plate 5018. With this arrangement, the material entering the material distribution channel 5017 from the material distribution inlet 5011 is evenly distributed to multiple flow paths, and then leaves the material heating distributor 501 through each material distribution outlet 5012.

[0178] In this embodiment, the inner cylinder 5013 also includes a plurality of connecting plates 5021 extending from the outer periphery of the end plate 5018 to the front end of the outer cylinder. The plurality of connecting plates are connected to the outer peripheral wall of the outer cylinder 5014, thereby realizing a fixed connection between the inner cylinder and the outer cylinder.

[0179] refer to Figure 17 and Figure 18 The spiral pyrolysis reactor 502 is annular, including an annular inner wall 5023, an annular outer wall 5024 sleeved outside the inner wall, and an annular bottom wall 5025 connecting the inner wall and the outer wall.

[0180] The inner wall 5023 is connected to the second rear end of the inner cylinder 5013 and defines the superheated flue 5026 through which the flue gas passes. A spiral blade structure 5027 is provided between the inner wall and the outer wall, so as to form a spiral material pyrolysis channel between the inner wall and the outer wall.

[0181] The material pyrolysis inlet 5021 is located at the front end of the material pyrolysis channel and is connected to the material distribution outlet 5012 of the material heating distributor 501. The rear end of the material pyrolysis channel is closed by the bottom wall 5025, and the outer wall 5024 is provided with material outlets that are connected to the material pyrolysis channel and the product outlet pipe, respectively.

[0182] The material distribution channel 5017 is connected to the material pyrolysis channel via the material distribution outlet 5012 and the material pyrolysis inlet 5021, forming a closed space. Within this closed space, the material is heated and undergoes a pyrolysis reaction, then discharged through the material outlet. A portion of the high-temperature flue gas flows through the outer wall, heating the material in the pyrolysis channel from the outside. Another portion of the high-temperature flue gas enters the superheated flue 5026, heating the material in the pyrolysis channel from the inside. This dual-sided heating ensures the material is fully heated, improving the efficiency of the heating and pyrolysis reaction. The temperature inside the superheated flue can reach 1150–1250℃, maintaining the temperature of the inner cylinder at 1000–1150℃. Furthermore, the spiral-shaped material pyrolysis channel extends the pyrolysis reaction path of the material, ensuring complete pyrolysis.

[0183] The superheated flue 5026 is connected to the flue gas inlet 5019. The high-temperature flue gas first enters the superheated flue 5026 and then enters the flue gas inlet 5019 to heat the material.

[0184] Preferably, the split pyrolysis reactor further includes an ash collector (not shown), which is connected to the material outlet of the spiral pyrolysis reactor 502 for collecting ash.

[0185] Further, refer to Figure 12 The equipment also includes a flue gas heat exchanger and a product heat exchanger. The flue gas heat exchanger is located at the outlet end of the flue gas outlet pipe GE, and the product heat exchanger is located at the outlet end of the product outlet pipe PE. Specifically, the flue gas heat exchanger includes a high-temperature flue gas heat exchanger 404 and a low-temperature flue gas heat exchanger 405 connected in series, and the product heat exchanger includes a high-temperature product heat exchanger 406 and a low-temperature product heat exchanger 407 connected in series. The high-temperature flue gas first undergoes a first heat exchange in the high-temperature flue gas heat exchanger 404, and then undergoes a second heat exchange in the low-temperature flue gas heat exchanger 405 to fully utilize the heat of the flue gas. The discharged product first undergoes a first heat exchange in the high-temperature product heat exchanger 406, and then undergoes a second heat exchange in the low-temperature product heat exchanger 407. A negative pressure induced draft fan 403 is located at the outlet end of the low-temperature flue gas heat exchanger 405.

[0186] In this embodiment, to fully utilize the heat of the flue gas and product gas, the steam supply device (i.e., steam buffer tank 101) is connected to the water source 108 in sequence through a high-temperature flue gas heat exchanger 404, a high-temperature product heat exchanger 406, and a low-temperature product heat exchanger 407. Thus, the water supplied by the water source 108 exchanges heat with the low-temperature product heat exchanger 407, the high-temperature product heat exchanger 406, and the high-temperature flue gas heat exchanger 404 in sequence, forming steam, which enters the steam buffer tank 101 and is then supplied to the primary and secondary mixing devices. The temperature of the steam after heat exchange can reach 800–1000°C. Between the water source 108 and the low-temperature product heat exchanger 407, a pipeline pump, a softened water tank 109, a steam feed water pump, and a steam feed water flow pump are sequentially installed for water pumping, softening, and metering. A heat exchanger inlet regulating valve 116 is provided between the low-temperature flue gas heat exchanger 405 and the softened water tank 109. The heat exchanger inlet regulating valve 116 is used to regulate the cooling water flow rate of the low-temperature flue gas heat exchanger 405.

[0187] Negative pressure ventilation control system

[0188] In this embodiment, the negative pressure induced draft control system includes a controller, a negative pressure induced draft fan 403, a furnace temperature sensor, and an outlet flue gas temperature sensor. The negative pressure induced draft fan 403 is connected to the flue gas outlet pipe GE. The furnace temperature sensor and the outlet flue gas temperature sensor are used to measure the furnace temperature T1 and the flue gas temperature T2, respectively.

[0189] The controller adjusts the speed of the negative pressure induced draft fan and the power of the burner based on the measurement results from the furnace temperature sensor and the flue gas temperature sensor, so as to maintain the furnace temperature T1 and the flue gas temperature T2 within a certain temperature range. In this embodiment, T1 is maintained at 1150–1250℃, and T2 is maintained at 1000–1100℃. Various existing technologies can be used to adjust the speed of the induced draft fan, such as using a frequency converter.

[0190] Specifically, when the furnace temperature T1 is above the upper limit of its temperature range (e.g., above 1250°C) and the flue gas temperature T2 is above the upper limit of its temperature range (e.g., above 1100°C), the controller increases the speed of the negative pressure induced draft fan and decreases the power of the burner, thereby causing both the furnace temperature T1 and the flue gas temperature T2 to decrease simultaneously. When the furnace temperature T1 is below the lower limit of its temperature range (e.g., below 1150°C) and the flue gas temperature T2 is below the lower limit of its temperature range (e.g., below 1000°C), the controller decreases the speed of the negative pressure induced draft fan and increases the power of the burner, thereby causing both the furnace temperature T1 and the flue gas temperature T2 to increase simultaneously. In this way, the furnace temperature is maintained within a suitable reaction temperature range, while the flue gas temperature is controlled within a reasonable range. A PLC controller can be selected as the controller.

[0191] In this embodiment, the negative pressure exhaust control system also includes a feed valve and a product initial temperature sensor. The feed valve is located on the material inlet pipe MI, and the product initial temperature sensor is used to measure the product temperature T3 discharged from the product outlet pipe PE.

[0192] The controller controls the opening of the feed valve and / or the power of the burner based on the measurement results of the initial product temperature sensor, so that the product temperature T3 is maintained within a certain temperature range; in this embodiment, T3 is maintained at 850~950℃.

[0193] Specifically, when the product temperature T3 is higher than the upper limit of its temperature range (e.g., above 950°C), the controller increases the opening of the feed valve, thereby increasing the feed flow rate and lowering the product temperature T3; or it decreases the power of the burner, thus lowering the product temperature T3; or it simultaneously increases the opening of the feed valve and decreases the power of the burner, thus lowering the product temperature T3. When the product temperature T3 is lower than the lower limit of its temperature range (e.g., below 850°C), the controller decreases the opening of the feed valve, thereby decreasing the feed flow rate and raising the product temperature T3; or it increases the power of the burner, thus raising the product temperature T3; or it simultaneously decreases the opening of the feed valve and increases the power of the burner, thus raising the product temperature T3.

[0194] The negative pressure induced draft control system also includes a flue gas final emission temperature sensor, which is located between the negative pressure induced draft fan and the outlet end of the 403 low-temperature flue gas heat exchanger 405, and is used to measure the final emission temperature of the flue gas.

[0195] The controller adjusts the inlet water regulating valve 116 according to the measurement results of the flue gas final emission temperature sensor, thereby controlling the cooling water flow of the low-temperature flue gas heat exchanger 405 so that the final emission temperature T5 of the flue gas is maintained within a certain temperature range; in this embodiment, T5 is maintained at 50-60°C.

[0196] Specifically, when the final emission temperature T5 of the flue gas is higher than the upper limit of its temperature range (e.g., higher than 60°C), the controller adjusts the inlet water regulating valve 116 to increase the cooling water flow rate, thereby reducing the final emission temperature T5 of the flue gas; when the final emission temperature T5 of the flue gas is lower than the lower limit of its temperature range (e.g., lower than 50°C), the controller adjusts the inlet water regulating valve 116 to decrease the cooling water flow rate, thereby increasing the final emission temperature T5 of the flue gas.

[0197] Preferably, the negative pressure exhaust control system further includes a pressure sensor, a pressure control tank 409, and a pressure control valve 408 disposed between the high-temperature product heat exchanger 406 and the low-temperature product heat exchanger 407. The controller adjusts the pressure control tank and the pressure control valve according to the measurement results of the pressure sensor to keep the product pressure discharged through the product outlet pipe within a preset pressure range. In this embodiment, the preset pressure range is 0.5 to 1.0 MPa.

[0198] By significantly improving carbon utilization efficiency, the raw material cost of this invention can be reduced by half compared to the average raw material cost of existing coal-to-natural-gas processes. Compared to traditional oxygen-assisted or aerobic pyrolysis processes in coal-to-natural-gas production, this invention improves thermal efficiency by over 50% through the reciprocating use of heat energy, directly reducing production costs. Furthermore, because water is used as the pyrolysis agent, reactant, auxiliary catalyst, and detergent, and elemental metals and non-metals from coal byproducts are used as catalysts, the process of this invention generates only small amounts or no pollutants, making it environmentally friendly.

[0199] 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 water-based process for producing natural gas, characterized in that, In an oxygen-isolated environment, the atomized coal-water slurry feedstock is contacted with high-temperature steam at 800~1000℃. The system undergoes multi-stage mixing and heating to raise the temperature to 200~400℃, and then continues to raise the temperature to the temperature required for the pyrolysis reaction, resulting in a product gas containing natural gas. The high-temperature steam serves as a pyrolysis agent, reactant, and auxiliary catalyst, while the product gas serves as an atomizing agent for the coal-water slurry feedstock. The step of obtaining the product gas is carried out in a single heated reaction vessel, without the addition of an industrial catalyst to the reaction system, and without separating the solid components in the system before the pyrolysis reaction. The multi-stage mixing and heating process to 200~400℃ includes: the atomized coal-water slurry raw material is contacted with high-temperature steam in the primary mixing device and heated to 100~150℃, and then contacted with high-temperature steam again in the secondary mixing device and heated to 200~400℃. The primary mixing device is a vortex heating coal injection gun device, comprising: a coal injection gun body, wherein the coal injection gun body is provided with a mixing channel, a mist material channel and at least one heating steam channel, one end of the mixing channel is open, the heating steam channel is spiral-shaped, one end of the heating steam channel is connected to the other end of the mixing channel, one end of the mist material channel is connected to one end of the heating steam channel through a branch channel, and the axis of the branch channel forms an angle with the axis of the mist material channel; The secondary heat mixing device is a multi-angle distributed heat mixing device, comprising: a heat mixing shell, which is cylindrical, and a heat mixing channel is provided inside the heat mixing shell; multiple heating pipes, which are connected to the heat mixing channel, and the multiple heating pipes are arranged sequentially at intervals along the axis of the heat mixing channel, and the multiple heating pipes are located at different circumferential angles on the radial cross section of the heat mixing channel.

2. The water-based process for producing natural gas according to claim 1, wherein, The high-temperature steam has a temperature of 900~1000℃ and a pressure of 1.2~1.8MPa.

3. The water-based process for producing natural gas according to claim 1, wherein, The particle size of the coal powder in the coal-water slurry is 50-200 mesh.

4. The water-based process for producing natural gas according to any one of claims 1-3, wherein, The required temperature for the pyrolysis reaction is 700~1000℃.

5. The water-based process for producing natural gas according to claim 1, wherein, The step of continuing to heat to the temperature required for the pyrolysis reaction is carried out in the heated reaction vessel, which is a high-temperature flue gas furnace.

6. The water-based process for producing natural gas according to claim 5, wherein, The system temperature inside the heating reaction vessel is controlled at 1150~1250℃, and the system pressure is controlled at 0.5~1.0MPa.

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