A pre-combustion carbon capture production system for a coal-fired thermal power plant
Patent Information
- Application Number
- CN202510264420.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2026-09-08
AI Technical Summary
[0003]传统的燃煤火力发电厂中，为了提高燃烧效率，原煤经磨煤机变成粉煤，进入锅炉燃烧，锅炉产蒸汽用于发电，然而此时锅炉排烟中含有大量CO2，导致碳排放量较高
[0023] The production system of this application generates electricity from coal-fired power plants while simultaneously gasifying a portion of the raw coal using a gasifier to obtain a first syngas containing CO2, CO, H2S, and H2. The first syngas is then separated in a gas separation device, and the resulting CO2 and CO mixture is collected. The H2 is then adjusted in proportion in a component blending device and fed into the power plant boiler as gas fuel for combustion to produce high-temperature and high-pressure steam. This allows for the early capture of carbon from the fuel in coal-fired power plants, reducing carbon emissions.
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Figure CN122708321A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of carbon capture technology, and in particular relates to a carbon capture production system before combustion in a coal-fired power plant. Background Technology
[0002] In thermal power plants, fuels such as coal, oil, natural gas, or biomass are burned in boilers, releasing a large amount of heat energy. Water in the boilers is heated and evaporates into high-temperature, high-pressure steam. This steam has enormous kinetic and potential energy, which can drive the blades of a steam turbine or gas turbine to rotate. The steam turbine is connected to a generator via a coupling. When the steam turbine rotates, it drives the rotor inside the generator to rotate as well. The generator contains a series of magnetic fields and coils. When the rotor rotates, it cuts these magnetic field lines, thereby generating an induced current in the coils, thus realizing thermal power generation.
[0003] In traditional coal-fired power plants, in order to improve combustion efficiency, raw coal is pulverized into coal through a coal mill and then burned in a boiler. The boiler produces steam for power generation. However, the flue gas from the boiler contains a large amount of CO2, resulting in high carbon emissions.
[0004] Therefore, how coal-fired power plants can capture carbon at low cost and reduce carbon emissions has become a concern for technicians. Summary of the Invention
[0005] Existing technologies present the challenge of how to capture carbon at low cost and reduce carbon emissions from coal-fired power plants.
[0006] To address the aforementioned technical problems, this application provides a pre-combustion carbon capture and production system for coal-fired power plants, comprising:
[0007] A power plant boiler is used to burn coal to produce steam, which is then supplied to a steam turbine generator.
[0008] A gasifier that uses oxygen and coal to produce primary syngas, which contains at least CO2, CO, H2S and H2.
[0009] A heat recovery unit is used to recover the heat and water vapor from the first syngas to obtain a dry second syngas;
[0010] A gas separation unit is used to separate the second syngas to obtain a mixture of CO2 and CO, and a third syngas.
[0011] The component blending device is used to adjust the proportion of hydrogen in the third synthesis gas and supply the resulting mixed gas to the boiler.
[0012] Furthermore, the component blending device is used to mix the third syngas with the second syngas and to adjust the proportion of hydrogen in the third syngas.
[0013] Furthermore, the component blending device is used to mix the third syngas with a CO2 and CO mixture to adjust the proportion of hydrogen in the third syngas.
[0014] Furthermore, the heat recovery unit uses water as a medium to exchange heat with the first syngas, and also obtains low-pressure steam and condensate.
[0015] Furthermore, an air separation device is used to produce the oxygen required for the gasification furnace; and / or,
[0016] An electrolysis water device is used to produce oxygen for a gasification furnace.
[0017] Furthermore, the coal burned in the boiler is raw coal type 1; the coal used in the gasifier is raw coal type 2; the proportion of raw coal type 2 is not less than 10% of the total weight of raw coal type 1 and raw coal type 2.
[0018] Furthermore, the low-pressure steam obtained from the first syngas produced by the gasifier is provided for the power plant's own use or for heat users.
[0019] Furthermore, the low-pressure steam generated through heat recovery is supplied to the power plant for its own use or to heat users.
[0020] Furthermore, the gasifier can be one of the following types: fixed bed, fluidized bed, or entrained flow bed.
[0021] Furthermore, the source of superheated steam in the gasifier is steam extracted from the power plant turbine or steam boiler.
[0022] The above-described technical solution of the present invention has at least the following beneficial technical effects:
[0023] The production system of this application generates electricity from coal-fired power plants while simultaneously gasifying a portion of the raw coal using a gasifier to obtain a first syngas containing CO2, CO, H2S, and H2. The first syngas is then separated in a gas separation device, and the resulting CO2 and CO mixture is collected. The H2 is then adjusted in proportion in a component blending device and fed into the power plant boiler as gas fuel for combustion to produce high-temperature and high-pressure steam. This allows for the early capture of carbon from the fuel in coal-fired power plants, reducing carbon emissions. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a structural diagram of a carbon capture production system before combustion in a coal-fired power plant, according to one embodiment of this application.
[0026] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows:
[0027] 1. Power plant boiler; 2. Gasifier; 3. Heat recovery device; 4. Gas separation device; 5. Component blending device; 6. Coal mill; 7. Steam turbine generator. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.
[0029] According to some embodiments, this application provides a pre-combustion carbon capture production system for a coal-fired power plant, comprising:
[0030] The power plant boiler 1 in this application burns coal to produce high-temperature and high-pressure main steam; the steam turbine generator 7 includes a steam turbine unit and a generator, and the steam turbine generator 7 generates electricity using the high-temperature and high-pressure main steam; furthermore, the power plant boiler 1 is capable of burning gaseous fuels to produce main steam.
[0031] To reduce carbon emissions from the power plant boiler 1, the production system of this application, while using coal-fired power generation, also performs carbon capture treatment on a portion of the coal to convert it into gaseous fuel; correspondingly, the production system is equipped with a gasifier 2, a heat recovery device 3, a gas separation device 4, and a component blending device 5, wherein:
[0032] Gasifier 2 is capable of producing a first syngas using oxygen and coal. The first syngas contains at least CO2, CO, H2S, and H2. Optionally, depending on the type of coal and the amount of heat released during synthesis, steam is added during the gasification process. The steam and oxygen are introduced into gasifier 2 together. The first syngas is generated at a pressure of 4 MPa, 5.5 MPa, or 6.5 MPa. At this time, the dry basis composition of the first syngas includes, but is not limited to, 65% CO, 28% H2, 7% CO2, and 0.5% H2S.
[0033] After obtaining the first syngas, the heat recovery device 3 recovers the heat and water vapor therein, drying the first syngas to obtain the second syngas. The conversion temperature of the heat recovery device 3 is controlled between 20 and 50°C. A water medium heat exchanger can be installed in the heat recovery device 3. The medium water in the heat exchanger absorbs the heat of the second syngas and is converted into low-pressure steam. The water vapor in the first syngas is converted into condensate and discharged, thus reducing the water content.
[0034] The gas separation device 4 is used to separate the second synthesis gas to obtain a CO2 and CO mixture and a third synthesis gas; wherein the third synthesis gas mainly contains H2 and a small amount of H2S; optionally, the CO2 and CO mixture obtained from the separation of the second synthesis gas can be collected together, or CO2 and CO can be separated again and collected separately.
[0035] Since hydrogen is a flammable and explosive gas, in order to ensure the safety of the production system, the proportion of hydrogen in the third synthesis gas is adjusted by the component blending device 5. The resulting mixed gas is under high pressure, and the pressure depends on the gasification pressure. The mixed gas can be depressurized and then supplied to the power plant boiler 1 to replace part of the coal or to assist combustion.
[0036] The production system of this application generates electricity from coal-fired power plants while using a gasifier 2 to gasify a portion of the raw coal to obtain a first syngas containing CO2, CO, H2S and H2. The first syngas is then separated in a gas separation device 4. The separated CO2 and CO mixture is collected, and the H2 is adjusted in proportion in a component blending device 5 before being fed into the power plant boiler 1 as gaseous fuel to produce high-temperature and high-pressure steam. This allows carbon in the fuel of the coal-fired power plant to be captured in advance, reducing carbon emissions.
[0037] In a specific embodiment of this application, the component blending device 5 can adjust the proportion of hydrogen in the third synthesis gas in various ways, and one or more of various blending methods can be used. The mass proportion of hydrogen in the blended gas mixture is 50%-98%. The specific blending methods are as follows:
[0038] Optionally, the component blending device 5 mixes the third syngas with the second syngas to adjust the proportion of hydrogen in the third syngas.
[0039] Optionally, the component blending device 5 mixes the third syngas with a CO2 and CO mixture to adjust the proportion of hydrogen in the third syngas.
[0040] Preferably, the third syngas, after being mixed by the component mixing device 5, is still under high pressure.
[0041] In one specific embodiment of this application, the production system further includes an air separation device and / or a water electrolysis device;
[0042] The air separation unit obtains the oxygen required by gasifier 2 by separating air. The water electrolysis unit produces the oxygen required by gasifier 2 by electrolyzing water. One or both methods of oxygen supply can be used simultaneously.
[0043] Preferably, the coal burned in the boiler is raw coal type 1; the coal used in the gasifier 2 is raw coal type 2; the proportion of raw coal type 2 is not less than 10% of the total weight of raw coal type 1 and raw coal type 2, in order to achieve better carbon reduction effect. Optionally, raw coal type 1 is first ground into pulverized coal by the coal mill 6 and then fed into the power plant boiler 1 for combustion, and the main steam generated by combustion is introduced into the steam turbine generator set for power generation. Raw coal type 2 is ground into pulverized coal by the coal mill 6 and dried, and finally fed into the gasifier 2 for gasification.
[0044] In one embodiment of this application, the gasifier 2 is one or more of a fixed bed, fluidized bed, and entrained flow bed type. The gasifier 2 produces slag and black water during the coal gasification process; the slag removal device and black water treatment device are not limited in this application.
[0045] Preferably, the low-pressure steam obtained from the first syngas produced by the gasifier 2 is provided to the power plant for its own use or to heat users.
[0046] Preferably, when the heat recovery device 3 uses medium water to absorb heat from the first synthesis gas, the low-pressure steam converted from the medium water is supplied to the power plant for its own use or to heat users.
[0047] In one embodiment of this application, in addition to pulverized coal burners, gas fuel burners are also added to the existing power plant boiler 1.
[0048] In one embodiment of this application, the gas separation device 4 may employ absorption separation, adsorption separation, membrane separation, and chemical absorption separation to separate and collect CO2 and CO, thereby achieving the purpose of carbon capture.
[0049] In one embodiment of this application, the source of superheated steam entering the gasifier 2 is steam extracted from the power plant turbine generator 7 or a steam boiler.
[0050] It should be noted that the shape and structure of the pipes used for transporting steam and syngas are not specifically limited in this application.
[0051] In the description of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0052] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this application and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this application should be included within the protection scope of this application. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A carbon capture and production system before combustion in a coal-fired power plant, characterized in that, include: The power plant boiler (1) is used to burn coal to produce steam for the steam turbine generator (7); Gasifier (2) uses oxygen and coal to produce first syngas, which contains at least CO2, CO, H2S and H2; Heat recovery device (3) is used to recover the heat and water vapor of the first synthesis gas to obtain a dry second synthesis gas; Gas separation device (4) is used to separate the second synthesis gas to obtain CO2, CO mixture and third synthesis gas respectively; The component blending device (5) is used to adjust the proportion of hydrogen in the third synthesis gas and supply the resulting mixed gas to the boiler.
2. The production system according to claim 1, characterized in that, The component blending device (5) is used to mix the third syngas with the second syngas and adjust the proportion of hydrogen in the third syngas.
3. The production system according to claim 1, characterized in that, The component blending device (5) is used to mix the third synthesis gas with CO2 and CO mixed gas and adjust the proportion of hydrogen in the third synthesis gas.
4. The production system according to claim 1, characterized in that, The heat recovery device (3) uses water as a medium to exchange heat with the first synthesis gas, and also obtains low-pressure steam and condensate.
5. The production system according to claim 1, characterized in that, An air separation device is used to prepare the oxygen required for the gasifier (2); and / or, An electrolysis water device is used to produce oxygen required for the gasifier (2).
6. The production system according to claim 1, characterized in that, The coal burned in the boiler is raw coal one; the coal used in the gasifier (2) is raw coal two; the proportion of raw coal two is not less than 10% of the total weight of raw coal one and raw coal two.
7. The production system according to claim 1, characterized in that, The low-pressure steam obtained from the first synthesis gas produced by the gasifier (2) is supplied to the power plant for its own use or to heat users.
8. The production system according to claim 1, characterized in that, The low-pressure steam generated through heat recovery is supplied to the power plant for its own use or to heat users.
9. The production system according to claim 1, characterized in that, The gasifier (2) is one of the following types: fixed bed, fluidized bed, and entrained flow bed.
10. The production system according to claim 1, characterized in that, The superheated steam source of the gasifier (2) is extracted from the power plant turbine or steam boiler.