A method and system for the synergistic decarbonization and utilization of coal gangue from organic waste.

Abstract

This invention provides a method for the decarbonization and utilization of coal gangue in conjunction with organic waste, comprising the following steps: Step S1, sorting the coal gangue; Step S2, mixing the sorted coal gangue with organic solid waste, followed by crushing and drying to obtain a crushed and dried mixture; Step S3, pyrolyzing the mixture to obtain solid semi-coke and volatile matter; Step S4, controlling the gasification of the solid semi-coke through catalytic volatile matter to obtain solid residue and combustible gas; Step S5, cooling the solid residue for land use or building material utilization; Step S6, purifying the combustible gas to obtain clean gas, which is then used for thermal energy utilization or power generation. In Step S4, high-temperature flue gas is introduced during the controllable gasification, and the solid residue is controlled for decarbonization by controlling the gasification temperature and the oxygen and water vapor content in the high-temperature flue gas. This invention also provides a system for the decarbonization and utilization of coal gangue in conjunction with organic waste.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, specifically relating to a method and system for the decarbonization and utilization of coal gangue in conjunction with organic waste. Background Technology

[0002] Coal gangue is a solid waste generated during coal mining and washing. It has a low carbon content and a high ash content. During storage, the sulfides and other substances contained in coal gangue can enter the air, soil, and water sources, polluting the environment and ultimately threatening human health. Furthermore, because coal gangue contains a certain amount of carbon, it can spontaneously combust when piled together, causing fires. The most convenient way to dispose of coal gangue is as filler for subsidence areas and pits in coal mines, as well as for subsided roads and dams. However, this method does not fully utilize the fixed carbon content in the coal gangue, resulting in low added value.

[0003] To fully utilize the fixed carbon components in coal gangue, pyrolysis gasification has become a new method for the resource utilization of coal gangue. Currently, there are many technologies for the utilization of coal gangue, such as (1) a comprehensive utilization method of coal gangue with synergistic organic waste (CN103992820A), which supplies coal gangue and coal together as gasification raw materials to the gasification equipment to produce gaseous fuels such as methane, effectively utilizing the fixed carbon components of coal gangue. Moreover, the silicon and aluminum components rich in coal gangue help to increase the ash melting point of solid residues and improve the slagging problem in the gasification equipment. (2) Coal gangue pyrolysis gasification method (CN103215085A) uses the combustible gas generated during the pyrolysis gasification of coal gangue for combustion, providing heat for the pyrolysis gasification of coal gangue, and also uses the residual heat of the solid products after the pyrolysis gasification of coal gangue to generate superheated steam, promoting the occurrence of water-gas reaction. (3) A comprehensive utilization system and method for coal gangue in conjunction with organic waste (CN112940783) involves continuous high-temperature pyrolysis and gasification of the carbon-rich material obtained from screening. The sensible heat of the obtained high-temperature combustible gas is used to heat steam as a gasifying agent. The low-temperature combustible gas is purified and then used to generate electricity in an internal combustion engine to power the screening system, gasification system, etc. In addition, the slag produced by pyrolysis and gasification can also be used as raw material to prepare materials such as ceramic short fibers, inorganic plates, and silicon-aluminum composite plates. The above-mentioned existing technologies are all based on pyrolysis and gasification technology to realize the resource utilization and harmless use of coal gangue, but the following problems have not yet been solved:

[0004] (1) Coal gangue has a low carbon content, and the calorific value of the combustible gas produced by the general gasification process is very low. The economic benefits of using it after purification are limited; direct combustion without purification can only utilize thermal energy, which is very limited.

[0005] (2) The cost of processing coal gangue separately is high, the amount of energy recovered is small, and the economic benefits are low.

[0006] (3) Different scenarios have different final requirements for coal gangue decarbonization, and a uniform decarbonization method cannot be used to deal with different carbon content requirements. Summary of the Invention

[0007] This invention was made to solve the above-mentioned problems, and its purpose is to provide a method and system for the synergistic decarbonization and utilization of coal gangue and organic waste.

[0008] This invention provides a method for the synergistic decarbonization and utilization of coal gangue from organic waste, characterized by the following steps:

[0009] Step S1: Separate the coal gangue;

[0010] Step S2: The sorted coal gangue is mixed with organic solid waste and then crushed and dried to obtain a crushed and dried mixture.

[0011] Step S3: The mixture is subjected to pyrolysis to obtain solid semi-coke and volatile matter;

[0012] Step S4 involves controlled gasification of solid semi-coke catalytic volatiles to obtain solid residue and combustible gas;

[0013] Step S5: After cooling the solid residue, it can be used for land application or building materials.

[0014] Step S6: After purifying the combustible gas to obtain clean gas, the clean gas is used for thermal energy utilization or power generation.

[0015] In step S4, the gasification temperature during controllable gasification is 790℃~890℃. During controllable gasification, high-temperature flue gas containing volatiles or clean combustion gas is also introduced. The gasification temperature is controlled by controlling the amount of high-temperature flue gas fed in, the oxygen content of the high-temperature flue gas, and the water vapor content of the high-temperature flue gas, and the solid semi-coke is decarbonized in a controllable manner.

[0016] The method for decarbonizing and utilizing coal gangue in conjunction with organic waste provided by this invention may also have the following features: when the solid residue is used for land application, the carbon content of the solid residue must be ≥5%; when controlled gasification is carried out, high-temperature flue gas generated by the combustion of volatiles is introduced, the gasification temperature is controlled at 790℃-850℃, and the oxygen content of the high-temperature flue gas is controlled at <11%, and the water vapor content is controlled at ≥10%.

[0017] When solid residues are used as building materials, the carbon content of the solid residues must be less than 5%. During controlled gasification, high-temperature flue gas generated by the combustion of clean fuel gas is introduced, the gasification temperature is controlled at 850℃-890℃, and the oxygen content of the high-temperature flue gas is controlled at ≥15%.

[0018] The method for decarbonizing and utilizing coal gangue from synergistic organic waste provided by the present invention may also have the following feature: in step S1, coal gangue with a carbon content ≥15% is sorted.

[0019] The method for decarbonizing and utilizing coal gangue with synergistic organic waste provided by the present invention may also have the following feature: wherein, in step S2, the organic solid waste is easily decomposable organic waste, including straw, domestic waste, waste plastics, waste rubber and waste medicine residue.

[0020] The method for decarbonization and utilization of coal gangue in synergistic organic waste provided by the present invention may also have the following feature: wherein, in step S3, the pyrolysis temperature during pyrolysis treatment is 450℃~650℃.

[0021] The method for decarbonizing and utilizing coal gangue from synergistic organic waste provided by the present invention may also have the following feature: wherein, in step S4, the temperature of the combustible gas obtained after controllable gasification is ≤800℃.

[0022] The present invention also provides a coal gangue decarbonization and utilization system for synergistic organic waste, characterized by comprising: a sorting device for sorting coal gangue;

[0023] A mixing and crushing device, connected to a sorting device, is used to mix and crush sorted coal gangue and organic solid waste to obtain a crushed mixture.

[0024] A dryer, connected to a mixing and pulverizing device, is used for drying mixtures;

[0025] A pyrolysis reactor, connected to a dryer, is used to pyrolyze a mixture to obtain solid semi-coke and volatiles;

[0026] A controllable gasifier, connected to a pyrolysis reactor, is used for the controllable gasification of solid semi-coke catalytic volatiles to obtain solid residue and combustible gas;

[0027] A cooling discharge device, connected to a controllable gasifier, is used to cool solid residues;

[0028] The purification device, connected to a controllable gasifier, is used to purify combustible gas to obtain clean gas.

[0029] The controllable gasifier is also connected to a combustion chamber for providing high-temperature flue gas. The combustion chamber is connected to a purification device and a pyrolysis reactor.

[0030] The combustion chamber is also circulated with an oxidant, which reacts with volatiles or clean fuel gas to produce high-temperature flue gas. A purification device is also injected into the combustion chamber to purify the wastewater produced by the combustible gas. The oxygen content of the high-temperature flue gas after combustion is controlled by controlling the amount of oxidant used, the water vapor content of the high-temperature flue gas is controlled by controlling the amount of wastewater injected, and the temperature of the high-temperature flue gas is also controlled.

[0031] The method for decarbonizing and utilizing coal gangue in synergistic organic waste provided by the present invention may also have the following features: wherein the pyrolysis reactor is provided with a volatile matter outlet and a semi-coke outlet, and the controllable gasifier is provided with a volatile matter inlet and a semi-coke inlet, the volatile matter outlet and the semi-coke outlet are connected to the volatile matter inlet and the semi-coke inlet respectively, and the solid semi-coke enters the controllable gasifier through the semi-coke inlet to form a solid semi-coke layer of ≥80mm, and the volatile matter passes through the solid semi-coke layer for gasification.

[0032] The method for decarbonizing and utilizing coal gangue in synergistic organic waste provided by the present invention may also have the following feature: wherein the pyrolysis reactor and the dryer are further connected to a heating device for providing heat.

[0033] The role and effect of invention

[0034] According to the present invention, a method and system for the co-processing of organic waste and coal gangue decarbonization and utilization involves the co-processing of organic solid waste and coal gangue. Taking advantage of the high yield of volatile matter from the pyrolysis of organic waste, the sensible heat of the high-temperature flue gas generated by the direct combustion of the volatile matter produced by the co-pyrolysis or the sensible heat of the high-temperature flue gas generated by the combustion of the final clean fuel gas is used to provide heat for the gasification reaction, promoting gasification. The calorific value of the generated combustible gas can reach twice that of the syngas produced by a conventional gasifier, effectively increasing the value of the final product. By utilizing the volatile matter of organic solid waste, the present invention avoids the use of additional fuel, maximizing the saving of external energy, and effectively solves the problems of tar clogging pipes and corroding equipment during the separate pyrolysis of organic waste.

[0035] Meanwhile, the product of this invention also includes solid residue. This invention achieves controllable decarbonization by controlling the gasification temperature and the oxygen and water vapor content of the high-temperature flue gas to obtain solid residue with corresponding carbon content. Therefore, this invention can perform controllable decarbonization according to different utilization scenarios of solid residue, which is convenient for the resource utilization needs of different regions. It can also reduce the temperature of the gasifier, avoid problems such as coking and carbon accumulation, and greatly improve the reliability and life of the gasifier. At the same time, it also cleanly treats the tar-containing wastewater generated by gas purification.

[0036] Therefore, by combining pyrolysis technology with controlled gasification technology, this invention effectively achieves controlled decarbonization and resource utilization of coal gangue, reduces the difficulty of coal gangue processing and utilization, lowers equipment requirements, and further reduces overall processing costs. Attached Figure Description

[0037] Figure 1 This is a schematic flowchart of a method for the synergistic decarbonization and utilization of coal gangue from organic waste according to the present invention.

[0038] Figure 2 This is a flowchart of the process of introducing volatile matter into the combustion chamber of a system for the synergistic decarbonization and utilization of organic waste and coal gangue according to the present invention.

[0039] Figure 3 This is a flowchart illustrating the process of introducing clean fuel gas into the combustion chamber of a system for the synergistic decarbonization and utilization of coal gangue and organic waste according to the present invention.

[0040] Figure 4 This is a schematic diagram of the working principle of the controllable gasification furnace of the present invention. Detailed Implementation

[0041] Figure 1 This is a schematic flowchart of a method for the synergistic decarbonization and utilization of coal gangue from organic waste according to the present invention.

[0042] like Figure 1 As shown, a method for the synergistic decarbonization and utilization of coal gangue from organic waste according to the present invention includes the following steps:

[0043] Step S1: Sort the coal gangue.

[0044] In step S1, coal gangue with a carbon content ≥15% is obtained through sorting. In this invention, sorting may also be omitted.

[0045] Step S2 involves mixing the sorted coal gangue with organic solid waste, followed by crushing and drying to obtain a crushed and dried mixture.

[0046] In step S2, the organic solid waste is easily decomposed organic waste, including straw, household waste, waste plastics, waste rubber, and waste medicine residue, etc.

[0047] Step S3: The mixture is subjected to pyrolysis to obtain solid semi-coke and volatiles.

[0048] In step S3, the pyrolysis temperature during the pyrolysis treatment is 450℃~650℃.

[0049] In step S4, the solid semi-coke is catalytically vaporized to obtain solid residue and combustible gas. In step S4, the temperature of the combustible gas obtained after controlled vaporization is ≤800℃.

[0050] In step S4, the gasification temperature during controlled gasification is 790℃~890℃. During controlled gasification, high-temperature flue gas containing volatiles or clean combustion gas is also introduced. The gasification temperature is controlled by controlling the amount of high-temperature flue gas fed in, the oxygen content of the high-temperature flue gas, and the water vapor content of the high-temperature flue gas, and the solid semi-coke is decarbonized in a controlled manner.

[0051] In this invention, the volatile matter produced during the pyrolysis stage of coal gangue is minimal. The sensible heat of the high-temperature flue gas generated from the direct combustion of the volatile matter produced during co-pyrolysis with waste, or the sensible heat of the high-temperature flue gas generated from the combustion of clean fuel gas, is used to provide heat for the gasification reaction, promoting gasification. Instead of being gasified by a large amount of air, the calorific value of the resulting combustible gas is twice that of syngas produced by a conventional gasifier, effectively increasing the value of the final product. Furthermore, the utilization of volatile matter also maximizes the conservation of external energy.

[0052] Meanwhile, coal gangue is heated during the co-pyrolysis process with waste. Both the pyrolysis semi-coke of waste and the coal gangue semi-coke contain catalytic components such as Ca and Mg. During the gasification process of high-temperature flue gas as a gasifying agent, the carbon in the pyrolysis semi-coke and coal gangue semi-coke is easily gasified to produce CO and H2.

[0053] In this invention, when solid residue is used for land application, the carbon content of the solid residue must be ≥5%. When it is gasified in a controlled manner, high-temperature flue gas generated by the combustion of volatiles is introduced, the gasification temperature is controlled at 790℃-850℃, and the oxygen content of the high-temperature flue gas is controlled at <11%, and the water vapor content is controlled at ≥10%.

[0054] When solid residues are used as building materials, the carbon content of the solid residues must be less than 5%. During controlled gasification, high-temperature flue gas generated by the combustion of clean fuel gas is introduced, the gasification temperature is controlled at 850℃-890℃, and the oxygen content of the high-temperature flue gas is controlled at ≥15%.

[0055] Step S5: After cooling the solid residue, it can be used for land application or building material application.

[0056] In this invention, the carbon content requirement of the solid residue can be determined according to the utilization scenario of the solid residue, and the solid residue with the corresponding carbon content can be obtained for use by controlling the high-temperature flue gas atmosphere and supply.

[0057] Step S6: After purifying the combustible gas, clean gas is obtained, and the clean gas is used for thermal energy utilization or power generation.

[0058] In this invention, since most of the tar has been removed, the tar problem is not particularly prominent when purifying combustible gas. The key is to remove particulate matter and polluting gases.

[0059] In this invention, the utilization of combustible gas includes thermal energy utilization, chemical utilization, and internal combustion engine power generation. Specific utilization scenarios may include fuel combustion in gas boilers, utilization as syngas for ethanol synthesis, and application scenarios such as power generation in internal combustion engines.

[0060] The present invention provides a system for decarbonizing and utilizing coal gangue in conjunction with organic waste, comprising a sorting device 1, a mixing and crushing device 2, a dryer 3, a pyrolysis reactor 4, a controllable gasification furnace 5, a combustion chamber 6, a cooling and discharging device 7, and a purification device 8.

[0061] The sorting device 1 is used to sort coal gangue. The sorting device 1 can be selected from sorting methods such as gravity medium shallow trough sorting, jigging sorting, and intelligent dry sorting.

[0062] The mixing and crushing device 2 is connected to the sorting device 1 and is used to mix and crush the sorted coal gangue and organic solid waste to obtain a crushed mixture. The mixing and crushing device 2 can be selected from crushers such as hammer crushers, roller crushers, jaw crushers, impact crushers, and twin-shaft shear crushers.

[0063] Dryer 3 is connected to mixing and pulverizing device 2 and is used to dry the mixture. Dryer 3 can be selected for direct drying from a rotary kiln or indirect drying.

[0064] The pyrolysis reactor 4 is connected to the dryer 3 and is used to pyrolyze the mixture to obtain solid semi-coke and volatiles. The pyrolysis reactor 4 can be selected from a rotary kiln or a spiral pyrolysis reactor.

[0065] The controllable gasifier 5 is connected to the pyrolysis reactor 4 and is used for controllable gasification of solid semi-coke catalytic volatiles to obtain solid residue and combustible gas.

[0066] The controllable gasifier 5 is also connected to a combustion chamber 6 for providing high-temperature flue gas. The combustion chamber 6 is connected to the purification device 8 and the pyrolysis reactor 4. The combustion chamber 6 can be selected from cylindrical or cuboid combustion chambers containing refractory bricks or insulating materials.

[0067] The combustion chamber 6 is also circulated with an oxidant, which reacts with volatiles or clean fuel gas to produce high-temperature flue gas. The combustion chamber 6 is also purified by a purification device 8 to purify the wastewater produced by the combustible gas. The oxygen content of the high-temperature flue gas after combustion is controlled by controlling the amount of oxidant used, the water vapor content of the high-temperature flue gas is controlled by controlling the amount of wastewater injected, and the temperature of the high-temperature flue gas is controlled. The gasification temperature in the controllable gasifier 5 is then controlled by controlling the amount of high-temperature flue gas fed in.

[0068] The oxidant is air, oxygen-enriched air, O2, etc., and the gas purification wastewater is the tar-containing wastewater generated after the gas purification device 8 purifies the gas.

[0069] Furthermore, the oxygen and water vapor content of the high-temperature flue gas obtained after combustion can be controlled by controlling the amount of oxidant and wastewater injected from the gas combustion process, as well as the flue gas temperature. The corresponding relationships can be calculated using the following formula:

[0070] L g ×HHV g -L s ×2500=Q y ×I y (1)

[0071] In formula (1), L g HHV g Q y I y These are the volume of the combustion gas or volatiles entering the combustion chamber, the higher heating value of the combustion gas, the volume of the generated flue gas, and the high-temperature enthalpy, respectively. s Wastewater volume. Flue gas volume Q y Calculated by the following formula:

[0072] Q y =Q ll +L s ×22.4 / 18 (2)

[0073] In formula (2), Q ll The amount of flue gas generated based on the given oxidant.

[0074] Figure 2 This is a flowchart illustrating the process of introducing volatile matter into the combustion chamber of a system for the synergistic decarbonization and utilization of coal gangue and organic waste according to the present invention.

[0075] like Figure 2 As shown, when using volatiles to generate high-temperature flue gas, the combustion chamber 6 is connected to the pyrolysis reactor 4. Part of the volatiles react with the oxidant in the combustion chamber 6 to generate high-temperature flue gas. At the same time, a small amount of wastewater generated from purification is injected. The high-temperature flue gas passes through the controllable gasification furnace 5. By controlling the amount of high-temperature flue gas fed in, as well as the oxygen and water vapor content of the high-temperature flue gas, the solid residue obtained after gasification can be used for land application.

[0076] Figure 3 This is a flowchart illustrating the process of introducing clean fuel gas into the combustion chamber of a system for the synergistic decarbonization and utilization of coal gangue and organic waste according to the present invention.

[0077] like Figure 3As shown, when using clean gas to generate high-temperature flue gas, the combustion chamber 6 is connected to the purification device 8. Part of the clean gas reacts with the oxidant in the combustion chamber 6 to generate high-temperature flue gas. At the same time, a small amount of wastewater generated from purification is injected. The high-temperature flue gas passes through the controllable gasification furnace 5. By controlling the amount of high-temperature flue gas fed in, as well as the oxygen and water vapor content of the high-temperature flue gas, the solid residue obtained after gasification can be used for building materials.

[0078] Figure 4 This is a schematic diagram of the working principle of the controllable gasification furnace of the present invention.

[0079] like Figure 4 As shown in the figure, this is a schematic diagram of the working principle when the controllable gasifier 5 of the present invention is selected as a grate-type gasifier. The controllable gasifier is provided with a semi-coke inlet 51, a volatile matter inlet 52, a high-temperature flue gas inlet 53, a rolling grate 54 disposed in the furnace, and a combustible gas outlet 55.

[0080] The pyrolysis reactor is equipped with a volatile matter outlet and a semi-coke outlet, which are connected to the volatile matter inlet 52 and the semi-coke inlet 51 respectively. Solid semi-coke enters the controllable gasification furnace 5 through the semi-coke inlet 51 to form a solid semi-coke layer of ≥80mm. Volatile matter passes through the solid semi-coke layer for gasification. During the gasification process, high-temperature flue gas is introduced through the high-temperature flue gas inlet 53 to provide heat for the gasification reaction and to carry out controllable decarbonization. After the gasification is completed, the combustible gas is sent out through the combustible gas outlet 55, and the solid residue is discharged from the furnace as the rolling grate 54 rotates.

[0081] The cooling discharge device 7 is connected to the controllable gasifier 6 and is used to cool the solid residue to <80°C. The cooling discharge device 7 can be selected from a water-cooled jacketed spiral or a water-cooled jacketed rotary drum.

[0082] In this invention, the combustion chamber 6 is also provided with an oxidant inlet, and the cooling discharge device 7 is also provided with a heat exchange component. The heat exchange component is connected to the oxidant inlet. Before the oxidant is sent into the combustion chamber 6, it is first sent into the cooling discharge device 7. After heat exchange with the solid residue through the heat exchange component, it is then sent into the combustion chamber 6 through the oxidant inlet to preheat the oxidant and make full use of the system's own waste heat.

[0083] The purification device 8 is connected to the controllable gasification furnace 6 to purify the combustible gas and obtain clean gas.

[0084] In this invention, the dryer 3 is also connected to the controllable gasification furnace 5 and the purification device 8. The combustible gas generated in the controllable gasification furnace 5 first enters the dryer 3 for heat exchange, providing some heat to the dryer 3, and then is sent to the purification device 8 for purification.

[0085] In this invention, the purification device 8 includes a dust removal device and a tar removal and acid removal device. Specifically, the dust removal device is connected to the combustible gas outlet of the controllable gasification furnace 5 and is used to remove particulate matter from the combustible gas. The tar removal device is located after the dust removal device and is used to remove tar from the combustible gas after dust removal. The acid removal device is located after the tar removal device and is used to remove gaseous pollutants such as H2S, HCl, and SO2 from the combustible gas, ultimately obtaining clean gas.

[0086] Preferably, the dust removal device is a combination of a cyclone dust collector and an oil spray tower; the tar removal device is preferably an electrostatic precipitator; and the acid removal device is preferably an alkali particle adsorption tower or an alkali washing tower.

[0087] The pyrolysis reactor and the dryer are also connected to a heating device for providing heat. The heating device can be a heat transfer system formed by the high-temperature flue gas from the hot blast furnace or the secondary combustion chamber flowing outside the material and inside the insulation material of the pyrolysis reactor.

[0088] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate a method and system for the synergistic decarbonization and utilization of coal gangue from organic waste.

[0089] <Example 1>

[0090] In this embodiment, the sorting device 1 is a shallow tank sorting device for heavy media, the mixing and crushing device 2 is a double roller crusher, the dryer 3 is a rotary kiln, the pyrolysis reactor 4 is a rotary kiln pyrolysis reactor, and the heating device is a hot air furnace.

[0091] Based on the synergistic organic waste coal gangue decarbonization and utilization system of this embodiment, a method for synergistic organic waste coal gangue decarbonization and utilization of this embodiment includes the following steps:

[0092] Step S1: The coal gangue with a carbon content greater than 15% is separated by the sorting device 1.

[0093] In step S2, the coal gangue and the combustible components in municipal solid waste are mixed at a mass ratio of 3:1 and fed into the mixing and crushing device 2. The crushed coal gangue and municipal solid waste are then fed into the dryer 3 to obtain a dry mixture of coal gangue and municipal solid waste with relatively uniform particle size.

[0094] In step S3, the dried mixture is fed into pyrolysis reactor 4, where the pyrolysis temperature is controlled at 580°C and the pyrolysis time is 30 min, to obtain solid semi-coke and volatile matter.

[0095] In step S4, the volatiles generated by pyrolysis are fed into the controllable gasification furnace 5, and the solid semi-coke generated is also fed into the controllable gasification furnace 5. The volatiles pass through a solid semi-coke layer of ≥80mm for gasification. The obtained combustible gas is sent to the purification device 8 for purification. Part of the obtained clean gas is sent into the combustion chamber 6. At the same time, oxygen-enriched air (containing 30% O2) is introduced into the combustion chamber 6, and a small amount of gas purification wastewater discharged from the purification device 8 is sprayed in, so that the residual O2 in the high-temperature flue gas generated by combustion in the combustion chamber 6 reaches 16%. The high-temperature flue gas is sent into the controllable gasification furnace 5, and the amount of high-temperature flue gas fed in is adjusted so that the gasification temperature in the controllable gasification furnace 5 is 890℃ and the reaction time is 30min, to obtain solid residue and combustible gas.

[0096] In step S5, the solid residue is fed into the cooling discharge device 7 for cooling, and after cooling, it is used as a raw material for cement clinker production.

[0097] In step S6, the combustible gas is purified to obtain clean gas. 30% of the clean combustible gas is also sent to the hot air furnace of the heating device to generate flue gas at 900°C, which is used to heat the pyrolysis reactor 4 and the dryer 3. The remaining clean gas is used to generate electricity in the internal combustion engine.

[0098] Tests and analysis revealed that the main components of the clean gas are CO, CH4, H2, CO2, and N2, with a calorific value of 10.5 MJ / Nm³. 3 The main components of the solid residue are SiO2, Al2O3, and CaO, with a carbon content of 3 wt%, indicating that the fixed carbon in both the coal gangue and the waste has been fully gasified.

[0099] In this embodiment, the combustion chamber 6 is also provided with an oxidant inlet, and the cooling discharge device 7 is also provided with a heat exchange component. The heat exchange component is connected to the oxidant inlet. Before the oxygen-enriched air is sent into the combustion chamber 6, the oxygen-enriched air is first sent into the cooling discharge device 7. After exchanging heat with the solid residue through the heat exchange component, it enters the combustion chamber 6 through the oxidant inlet, which effectively increases the temperature of the oxygen-enriched air and recovers the sensible heat of the solid residue.

[0100] Compared to disposing of coal gangue separately, the investment is almost no increase, but the operating costs are reduced by 30%.

[0101] <Example 2>

[0102] In this embodiment, the mixing and crushing device 2 is a hammer crusher, and the dryer 3 is a rotary kiln.

[0103] Based on the synergistic organic waste coal gangue decarbonization and utilization system of this embodiment, a method for synergistic organic waste coal gangue decarbonization and utilization of this embodiment includes the following steps:

[0104] Step S1: The coal gangue with a carbon content ≥15% is separated by the sorting device 1;

[0105] Step S2: The coal gangue and biomass anaerobic digester residue with a moisture content of 50% are mixed at a mass ratio of 2:1 and fed into the mixing and crushing device 2. The crushed coal gangue and pharmaceutical residue mixture is then fed into the dryer 3 for drying treatment to obtain a dry mixture with a particle size of 10mm-30mm.

[0106] In step S3, the dried mixture is fed into pyrolysis reactor 4, where the pyrolysis temperature is controlled at 510°C and the pyrolysis time is 35 min, to obtain solid semi-coke and volatile matter.

[0107] In step S4, some of the volatiles generated by pyrolysis are directly fed into combustion chamber 6, while most of the volatiles are fed into controlled gasification furnace 5. The resulting solid semi-coke is also fed into controlled gasification furnace 5. The volatiles pass through a solid semi-coke layer of ≥80mm for gasification. Simultaneously, air is introduced into combustion chamber 6, and a small amount of wastewater from the gas purification device 8 is injected. The high-temperature flue gas generated by combustion reaches a temperature of 1280℃, with a water vapor content of 15%. The high-temperature flue gas is fed into controlled gasification furnace 5, and the amount of high-temperature flue gas is adjusted to make the gasification temperature in controlled gasification furnace 5 840℃, with a reaction time of 40 minutes, yielding solid residue and combustible gas.

[0108] In step S5, the solid residue is fed into the cooling discharge device 7 for cooling, and after cooling, it is further utilized as soil backfill material.

[0109] Step S6 involves purifying the combustible gas to obtain clean gas, which is then further utilized.

[0110] In this embodiment, testing and analysis revealed that the main components of the clean gas are CO, N2, CH4, H2, C2H4, and CO2, with a calorific value of 12 MJ / Nm³. 3 The solid residue mainly consists of SiO2, Al2O3, CaO, MgO, FeO, etc., with a carbon content of 7wt%, and is used for land improvement.

[0111] Compared to disposing of coal gangue separately, the investment is almost negligible, but the revenue increases by 30%, with clean gas used for internal combustion engine power generation; the system itself in this embodiment can be powered by the internal combustion engine.

[0112] <Example 3>

[0113] In this embodiment, the mixing and crushing device 2 is a hammer crusher, and the dryer 3 is a rotary kiln.

[0114] Based on the synergistic organic waste coal gangue decarbonization and utilization system of this embodiment, a method for synergistic organic waste coal gangue decarbonization and utilization of this embodiment includes the following steps:

[0115] Step S1: The coal gangue with a carbon content ≥15% is separated by the sorting device 1;

[0116] Step S2: Mix the coal gangue with biomass waste (wheat straw) at a mass ratio of 2:1 and feed it into the mixing and crushing device 2. Then, feed the crushed coal gangue and pharmaceutical residue mixture into the dryer 3 for drying treatment to obtain a dry mixture with a particle size of 4mm-30mm.

[0117] In step S3, the dried mixture is fed into pyrolysis reactor 4, where the pyrolysis temperature is controlled at 450°C and the pyrolysis time is 36 min, to obtain solid semi-coke and volatile matter.

[0118] In step S4, some of the volatiles generated by pyrolysis are directly fed into combustion chamber 6, and most of the volatiles are fed into controllable gasification furnace 5. The solid semi-coke generated is also fed into controllable gasification furnace 5. The volatiles pass through a solid semi-coke layer of ≥80mm for gasification. At the same time, air is introduced into combustion chamber 6, and a small amount of wastewater from the gas purification device 8 is injected. The high-temperature flue gas generated by combustion reaches a temperature of 1230℃ and a water vapor content of 15%. The high-temperature flue gas is fed into controllable gasification furnace 5. The amount of high-temperature flue gas fed in is adjusted so that the gasification temperature in controllable gasification furnace 5 is 790℃ and the reaction time is 40min, resulting in solid residue and combustible gas.

[0119] In step S5, the solid residue is fed into the cooling discharge device 7 for cooling, and after cooling, it is further utilized as soil backfill material.

[0120] Step S6 involves purifying the combustible gas to obtain clean gas, which is then further utilized.

[0121] In this embodiment, testing and analysis revealed that the main components of the combustible gas are CO, CH4, H2, C2H4, and CO2, with a calorific value of 9.8 MJ / Nm³. 3 The solid residue mainly consists of SiO2, Al2O3, CaO, MgO, FeO, etc., with a carbon content of 9wt%. It can be used to remediate barren soil and increase fertility.

[0122] Compared to disposing of coal gangue alone, the investment is almost negligible, but the revenue increases by 32%, with the clean fuel gas being used for syngas production to produce ethanol or methane.

[0123] <Example 4>

[0124] In this embodiment, the mixing and crushing device 2 is a jaw crusher, and the dryer 3 is a rotary kiln.

[0125] Based on the synergistic organic waste coal gangue decarbonization and utilization system of this embodiment, a method for synergistic organic waste coal gangue decarbonization and utilization of this embodiment includes the following steps:

[0126] Step S1: In this embodiment, the coal gangue is not sorted.

[0127] Step S2: Mix coal gangue and urban garden waste at a mass ratio of 3:2 and feed them into the mixing and crushing device 2. Then, feed the crushed coal gangue and garden waste mixture into the dryer 3 for drying treatment to obtain a dry mixture with a particle size of 10mm-30mm.

[0128] In step S3, the dried mixture is fed into pyrolysis reactor 4, where the pyrolysis temperature is controlled at 550°C and the pyrolysis time is 30 min, to obtain solid semi-coke and volatile matter.

[0129] In step S4, some of the volatiles generated by pyrolysis are directly fed into combustion chamber 6, and most of the volatiles are fed into controllable gasification furnace 5. The solid semi-coke generated is also fed into controllable gasification furnace 5. The volatiles pass through a solid semi-coke layer of ≥80mm for gasification. At the same time, air is introduced into combustion chamber 6, and a small amount of gas purification wastewater discharged from purification device 8 is injected. The high-temperature flue gas generated by combustion reaches a temperature of 1260℃ and a water vapor content of 15%. The high-temperature flue gas is fed into controllable gasification furnace 5. The amount of high-temperature flue gas fed in is adjusted so that the gasification temperature in controllable gasification furnace 5 is 850℃ and the reaction time is 35min, resulting in solid residue and combustible gas.

[0130] In step S5, the solid residue is fed into the cooling discharge device 7 for cooling, and after cooling, it is further utilized as soil backfill material.

[0131] Step S6 involves purifying the combustible gas to obtain clean gas, which is then further utilized.

[0132] In this embodiment, testing and analysis revealed that the main components of the combustible gas are CO, CH4, H2, C2H4, and CO2, with a calorific value of 11.9 MJ / Nm³. 3 The solid residue mainly consists of SiO2, Al2O3, CaO, MgO, FeO, etc., with a carbon content of 8wt%. It can be used to remediate barren soil and increase fertility.

[0133] Compared to disposing of coal gangue alone, the investment increased by almost nothing, but the revenue increased by 35%, with the clean gas used for nearby heating boilers.

[0134] <Example 5>

[0135] In this embodiment, the sorting device 1 is a jigging sorting device, the mixing and crushing device 2 is a double-toothed roller crusher, the dryer 3 is a rotary kiln, the pyrolysis reactor 4 is a rotary kiln pyrolysis reactor, and the heating device is a hot air furnace.

[0136] Based on the synergistic organic waste coal gangue decarbonization and utilization system of this embodiment, a method for synergistic organic waste coal gangue decarbonization and utilization of this embodiment includes the following steps:

[0137] Step S1: The coal gangue with a carbon content greater than 15% is separated by the sorting device 1.

[0138] In step S2, the coal gangue and the combustible components in municipal solid waste are mixed at a mass ratio of 2:1 and fed into the mixing and crushing device 2. The crushed coal gangue and municipal solid waste are then fed into the dryer 3 to obtain a dry mixture of coal gangue and municipal solid waste with relatively uniform particle size.

[0139] In step S3, the dried mixture is fed into pyrolysis reactor 4, where the pyrolysis temperature is controlled at 650°C and the pyrolysis time is 20 min, to obtain solid semi-coke and volatiles.

[0140] In step S4, the volatiles generated by pyrolysis are fed into the controllable gasification furnace 5, and the solid semi-coke generated is also fed into the controllable gasification furnace 5. The volatiles pass through the solid semi-coke layer of ≥80mm for gasification. The obtained combustible gas is sent to the purification device 8 for purification. Part of the obtained clean gas is sent into the combustion chamber 6. At the same time, pure O2 is introduced into the combustion chamber 6 so that the residual O2 in the high-temperature flue gas generated by combustion in the combustion chamber 6 reaches 18%. A small amount of gas purification wastewater discharged from the purification device 8 is injected to make the flue gas temperature 1200℃. The high-temperature flue gas is sent into the controllable gasification furnace 5. The amount of high-temperature flue gas sent in is adjusted so that the gasification temperature in the controllable gasification furnace 5 is 890℃ and the reaction time is 45min, to obtain solid residue and combustible gas.

[0141] In step S5, the solid residue is fed into the cooling discharge device 7 for cooling, and after cooling, it is further utilized as a brick-making material.

[0142] In step S6, the combustible gas is sent to the purification device 8 for purification to obtain clean gas. 27% of the clean combustible gas is also sent to the heating device hot air furnace to generate flue gas at 900°C, which is used to heat the pyrolysis reactor 4 and the dryer 3. The remaining clean gas is used to generate electricity in the internal combustion engine.

[0143] In this embodiment, testing and analysis showed that the main components of the mixture of pyrolysis combustible gas and gasification combustible gas were CO, CH4, H2, CO2, and N2, with a calorific value of 11.1 MJ / Nm³. 3 The main components of the solid residue are SiO2, Al2O3, and CaO, with a carbon content of 2.1 wt%, indicating that the fixed carbon in both the coal gangue and the waste has been fully gasified.

[0144] In this embodiment, the combustion chamber 6 is also provided with an oxidant inlet and a wastewater spray inlet. The cooling discharge device 7 is also provided with a heat exchange component. The heat exchange component is connected to the oxidant inlet. Before the oxygen is sent into the combustion chamber 6, the oxygen is first sent into the cooling discharge device 7. After exchanging heat with the solid residue through the heat exchange component, the oxygen is then sent into the combustion chamber 6 through the oxidant inlet. This effectively increases the temperature of the oxygen and recovers the sensible heat of the solid residue.

[0145] Compared to disposing of coal gangue separately, the investment is almost negligible, but the overall operating cost of coal gangue and waste is reduced by 45%.

[0146] Example 6

[0147] In this embodiment, based on the method and system for utilizing coal gangue and organic waste proposed in Embodiment 5, the dryer 3 is also connected to the controllable gasification furnace 5 and the purification device 8. The combustible gas generated in the controllable gasification furnace 5 at 800°C first enters the dryer 3 to directly contact the mixture of coal gangue and waste for heat exchange and drying, and then is sent to the purification device 8. In this embodiment, 18% of the purified clean gas is also sent to a hot air furnace to generate flue gas at 900°C, which is used to heat the pyrolysis reactor 4 and the dryer 3. The remaining clean gas is used for internal combustion engine power generation.

[0148] The role and effect of the embodiments

[0149] As shown in Examples 1 and 5, when clean fuel gas is introduced into the controllable gasifier to react with the oxidant to produce high-temperature flue gas, and the gasification temperature is controlled by regulating the amount of high-temperature flue gas fed in, its oxygen content, and water vapor content, and controllable decarbonization is performed, low-carbon solid residue can be obtained after gasification for use in building materials. Furthermore, the sensible heat of the solid residue is used to preheat the oxidant, effectively utilizing the high-temperature sensible heat that would otherwise be wasted by the system itself.

[0150] As can be seen from Examples 2 to 4, when high-temperature flue gas generated by the combustion reaction of volatiles and oxidant is introduced into the controllable gasifier, and the gasification temperature is controlled by controlling the amount of high-temperature flue gas fed in, the oxygen content of the high-temperature flue gas and the amount of water vapor, and controllable decarbonization is carried out, solid residue with a high carbon content can be obtained after gasification for land use.

[0151] As can be seen from Example 6, in this example, in addition to preheating the oxidant by the sensible heat of the solid residue, the high-temperature combustible gas can also be used to contact the mixture of gangue and garbage for heat exchange and drying, which can maximize the use of the high-temperature sensible heat that the system itself would otherwise waste.

[0152] As shown in Examples 1 to 6, this invention can obtain clean fuel gas with high calorific value and solid residue with controllable carbon content for corresponding utilization, effectively reducing operating costs while increasing profits. This invention provides a method and system for the co-processing of organic waste and coal gangue decarbonization. By co-processing organic solid waste and coal gangue, and taking advantage of the high yield of volatile matter from the pyrolysis of organic waste, the sensible heat of the high-temperature flue gas generated by the direct combustion of the volatile matter produced by the co-pyrolysis treatment, or the sensible heat of the high-temperature flue gas generated by the combustion of the final clean fuel gas, provides heat for the gasification reaction, promoting gasification. The calorific value of the generated combustible gas can reach twice that of syngas produced by a conventional gasifier, effectively increasing the value of the final product. By utilizing the volatile matter of organic solid waste, this invention avoids the use of additional fuel, maximizing the saving of external energy, and effectively solves the problems of tar clogging pipes and corroding equipment during the separate pyrolysis of organic waste; it also partially solves the wastewater discharge problem.

[0153] Meanwhile, the product of this invention also includes solid residue. This invention achieves controllable decarbonization by controlling the gasification temperature and the oxygen and water vapor content of the high-temperature flue gas to obtain solid residue with corresponding carbon content. Therefore, this invention can perform controllable decarbonization according to different utilization scenarios of solid residue, which is convenient for the resource utilization needs of different regions. It can also reduce the temperature of the gasifier, avoid problems such as coking and carbon accumulation, and greatly improve the reliability and life of the gasifier.

[0154] Therefore, by combining pyrolysis technology with controlled gasification technology, this invention effectively achieves controlled decarbonization and resource utilization of coal gangue, reduces the difficulty of coal gangue processing and utilization, lowers equipment requirements, and further reduces overall processing costs.

[0155] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A method for the controlled decarbonization and utilization of coal gangue in conjunction with organic waste, characterized in that, Includes the following steps: Step S1: The coal gangue is sorted to obtain coal gangue with a carbon content ≥15%; Step S2: The sorted coal gangue is mixed with organic solid waste and then crushed and dried to obtain a crushed and dried mixture. Step S3: The mixture is subjected to pyrolysis to obtain solid semi-coke and volatiles; Step S4: The volatiles are controlled to gasify by the solid semi-coke to obtain solid residue and combustible gas; Step S5: After cooling the solid residue, it is used for land application or building material application; Step S6: The combustible gas is purified to obtain clean gas, which is then used for thermal energy utilization or power generation. In step S4, the gasification temperature during the controllable gasification is 790℃~890℃. During controllable gasification, high-temperature flue gas generated from the combustion of the volatiles or clean fuel is also introduced. The gasification temperature is controlled by adjusting the amount of high-temperature flue gas introduced, its oxygen content, and its water vapor content, thereby controlling the decarbonization of the solid semi-coke. When the solid residue is used for land application, the carbon content of the solid residue must be ≥5%. When the controllable gasification is carried out, the high-temperature flue gas generated by the combustion of the volatile matter is introduced, the gasification temperature is controlled at 790℃~850℃, and the oxygen content of the high-temperature flue gas is controlled at <11%, and the water vapor content is controlled at ≥10%. When the solid residue is used as building material, the carbon content of the solid residue must be <5%. During the controllable gasification, the high-temperature flue gas generated by the combustion of the clean fuel gas is introduced, the gasification temperature is controlled at 850℃~890℃, and the oxygen content of the high-temperature flue gas is controlled at ≥15%.

2. The method for controlled decarbonization and utilization of coal gangue from synergistic organic waste according to claim 1, characterized in that: in, In step S2, the organic solid waste is easily decomposed organic waste, including straw, household waste, waste plastics, waste rubber, and waste medicine residue.

3. The method for controlled decarbonization and utilization of coal gangue from synergistic organic waste according to claim 1, characterized in that: in, In step S3, the pyrolysis temperature during the pyrolysis treatment is 450℃~650℃.

4. The method for controlled decarbonization and utilization of coal gangue from synergistic organic waste according to claim 1, characterized in that: in, In step S4, the temperature of the combustible gas obtained after controllable gasification is ≤800℃.

5. A controllable decarbonization and utilization system for coal gangue in conjunction with organic waste, characterized in that, include: The sorting device is used to sort coal gangue; A mixing and crushing device, connected to the sorting device, is used to mix and crush the sorted coal gangue and organic solid waste to obtain a crushed mixture; A dryer, connected to the mixing and pulverizing device, is used for drying the mixture; A pyrolysis reactor, connected to the dryer, is used to pyrolyze the mixture to obtain solid semi-coke and volatiles; A controllable gasification furnace, connected to the pyrolysis reactor, is used to controllably gasify the volatiles through the solid semi-coke to obtain solid residue and combustible gas; A cooling discharge device, connected to the controllable gasification furnace, is used to cool the solid residue; A purification device, connected to the controllable gasifier, is used to purify the combustible gas to obtain clean gas. The controllable gasifier is also connected to a combustion chamber for providing high-temperature flue gas. This combustion chamber is connected to the purification device and the pyrolysis reactor. The combustion chamber is also supplied with an oxidant, which reacts with the volatiles or the clean fuel gas to generate the high-temperature flue gas. The combustion chamber is also supplied with the purification device to purify the wastewater generated by the combustible gas. The oxygen content of the high-temperature flue gas after combustion is controlled by controlling the amount of oxidant used, and the water vapor content of the high-temperature flue gas is controlled by controlling the amount of wastewater injected, and the temperature of the high-temperature flue gas is also controlled.

6. The controllable decarbonization and utilization system for coal gangue in conjunction with organic waste according to claim 5, characterized in that: in, The pyrolysis reactor is provided with a volatile matter outlet and a semi-coke outlet, and the controllable gasification furnace is provided with a volatile matter inlet and a semi-coke inlet. The volatile matter outlet and the semi-coke outlet are connected to the volatile matter inlet and the semi-coke inlet respectively. The solid semi-coke enters the controllable gasification furnace through the semi-coke inlet to form a solid semi-coke layer of ≥80mm. The volatile matter passes through the solid semi-coke layer and is gasified. When the controllable gasifier is selected as a grate-type gasifier, the combustible gas after gasification is completed is sent out through the combustible gas outlet, and the solid residue is discharged from the furnace as the rolling grate rotates.

7. The controllable decarbonization and utilization system for coal gangue in conjunction with organic waste according to claim 5, characterized in that: in, The pyrolysis reactor and the dryer are also connected to a heating device for providing heat.

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