System for reducing carbon dioxide emission in coking production process

Abstract

The utility model relates to a system for reducing carbon dioxide emission in a coking production process. The system comprises a coke oven heating system, a flue gas desulfurization and denitrification system, a CO2 absorption and analysis system, a methanol synthesis system, a wind power / photovoltaic power generation system, an energy storage system, a water electrolysis hydrogen production system, a hydrogen storage system and a methanol storage system. According to the device, the emission of coke oven flue gas CO2 to the atmosphere can be effectively reduced, the CO2 in the coke oven flue gas can be captured and converted into a green methanol fuel, and the CO2 generated by combustion is not discharged when the green methanol fuel is used as a heating fuel of a coke oven, so that the cyclic utilization and green development of the CO2 are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of coking and environmental protection, in particular to a system for reducing carbon dioxide emissions in a coking production process. Background Art

[0002] As the largest emitter of carbon dioxide (CO2), the steel industry currently faces immense pressure and challenges to reduce carbon emissions. The coking process, which provides coke for steelmaking and produces coke oven gas and coking chemicals as byproducts, has also drawn widespread attention for its CO2 emissions.

[0003] The coking production of steel joint ventures uses a mixture of blast furnace gas (also known as lean gas) and coke oven gas as fuel; while independent coking enterprises use coke oven gas as fuel. Since the current emission standards for chemical pollutants in coking only regulate NO in coke oven flue gas, X The emission of pollutants such as NO and SO2 has been limited. Therefore, most companies currently only focus on NO in flue gas. X and SO2 are controlled, but little attention is paid to the emission of CO2 in coke oven flue gas.

[0004] A Chinese utility model patent, granted with publication number CN 210186825 U, discloses a "system for reducing carbon dioxide emissions from coke oven flue gas." The system absorbs carbon dioxide from the coke oven flue gas with aqueous ammonia, converting it into an ammonium bicarbonate solution. This solution is then decomposed using aqueous sulfuric acid. The decomposed CO₂ is then returned to the coke oven carbonization chamber of the high-temperature coal dry distillation system, where it reacts with coke to produce CO, thereby converting the carbon dioxide in the coke oven flue gas into CO in the coke oven gas. However, this conversion process consumes coke, reducing coke production. Furthermore, this conversion process alters the composition of the coke oven gas, increasing the CO content and the carbon content in the coke oven gas. Consequently, the CO₂ content in the coke oven flue gas using this coke oven gas as recycled fuel will also increase.

[0005] A Chinese utility model patent, granted with publication number CN 215667859 U, discloses a "coke oven gas carbon reduction and resource utilization system." This system separates coke oven gas components, using low-carbon hydrogen and high-calorific value methane as coke oven heating fuel. The hydrogen byproduct of combustion is called "ash hydrogen." However, methane combustion still produces carbon dioxide emissions, and the carbon dioxide reduced is only the CO2 and CO content in the coke oven gas, which together account for less than 10% of the carbon content of the coke oven flue gas. Therefore, the carbon emission reduction effect is very limited.

[0006] Neither of the above two existing technologies can fundamentally solve the problem of carbon dioxide emissions from coke oven flue gas. Therefore, it is necessary to adopt a greener and lower-carbon process route to improve the resource utilization efficiency of coke oven gas and reduce carbon dioxide emissions during the coke production process. Summary of the Invention

[0007] The utility model provides a system for reducing carbon dioxide emissions during the coking production process, which can effectively reduce the emission of CO2 from coke oven flue gas into the atmosphere, and can capture CO2 in the coke oven flue gas and convert it into green methanol fuel. When the CO2 is used as a heating fuel for the coke oven, the CO2 generated by combustion is not discharged, thereby realizing the recycling of CO2 and green development.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A system for reducing carbon dioxide emissions during the coking production process, including a coke oven heating system, a flue gas desulfurization and denitrification system, a CO2 absorption and analysis system, a methanol synthesis system, a wind power / photovoltaic power generation system, an energy storage system, a water electrolysis hydrogen production system, a hydrogen storage system, and a methanol storage system;

[0010] The coke oven flue gas outlet of the coke oven heating system is connected to the flue gas inlet of the flue gas desulfurization and denitrification system through a coke oven flue gas transmission pipeline, the flue gas outlet of the flue gas desulfurization and denitrification system is connected to the flue gas inlet of the CO2 absorption and desorption system through a flue gas pipeline, the CO2 gas outlet of the CO2 absorption and desorption system is connected to the CO2 gas inlet of the methanol synthesis system, and the residual flue gas outlet of the CO2 absorption and desorption system is connected to the chimney;

[0011] The power supply outlet of the wind power / photovoltaic power generation system is connected to the power supply inlet of the water electrolysis hydrogen production system through a cable on one side, and is connected to the power supply inlet of the energy storage system on the other side; the power supply outlet of the energy storage system is connected to the power supply inlet of the water electrolysis hydrogen production system; the hydrogen outlet of the water electrolysis hydrogen production system is connected to the hydrogen inlet of the hydrogen storage system through a hydrogen transmission pipeline, and the hydrogen outlet of the hydrogen storage system is connected to the hydrogen inlet of the methanol synthesis system through a hydrogen transmission pipeline;

[0012] The methanol outlet of the methanol synthesis system is connected to the methanol inlet of the methanol storage system through a methanol delivery pipeline, and the methanol outlet of the methanol storage system is connected to the fuel inlet of the coke oven heating system through a methanol delivery pipeline.

[0013] Furthermore, the hydrogen storage system is provided with a hydrogen spherical tank for hydrogen buffer storage.

[0014] Furthermore, the methanol storage system is provided with a methanol vertical tank for methanol buffer storage.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1) It can significantly improve the green level of the coking process: green hydrogen produced by green electricity is coupled with carbon dioxide separated from coke oven flue gas to produce green methanol, which is used as the heating fuel for the coke oven.

[0017] 2) Realize the recycling of CO2: The CO2 after the combustion of green methanol can be captured and reacted with green hydrogen produced by green electricity to produce green methanol.

[0018] 3) It can significantly reduce carbon emissions from the coking production process: the removal rate of CO2 in the coke oven flue gas is ≥85%, and the CO2 concentration in the remaining flue gas can be as low as below 50PPM.

[0019] 4) The coking by-product - coke oven gas has increased significantly: coke oven gas is no longer used as a heating fuel, so more coke oven gas can be used to produce chemical products such as hydrogen, LNG, synthetic ammonia, methanol, gasoline, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the composition of a system for reducing carbon dioxide emissions in a coking production process described in the utility model. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0022] like Figure 1 As shown, the system for reducing carbon dioxide emissions in the coking production process described in the utility model includes a coke oven heating system, a flue gas desulfurization and denitrification system, a CO2 absorption and analysis system, a methanol synthesis system, a wind power / photovoltaic power generation system, an energy storage system, a water electrolysis hydrogen production system, a hydrogen storage system and a methanol storage system;

[0023] The coke oven flue gas outlet of the coke oven heating system is connected to the flue gas inlet of the flue gas desulfurization and denitrification system through a coke oven flue gas transmission pipeline, the flue gas outlet of the flue gas desulfurization and denitrification system is connected to the flue gas inlet of the CO2 absorption and desorption system through a flue gas pipeline, the CO2 gas outlet of the CO2 absorption and desorption system is connected to the CO2 gas inlet of the methanol synthesis system, and the residual flue gas outlet of the CO2 absorption and desorption system is connected to the chimney;

[0024] The power supply outlet of the wind power / photovoltaic power generation system is connected to the power supply inlet of the water electrolysis hydrogen production system through a cable on one side, and is connected to the power supply inlet of the energy storage system on the other side; the power supply outlet of the energy storage system is connected to the power supply inlet of the water electrolysis hydrogen production system; the hydrogen outlet of the water electrolysis hydrogen production system is connected to the hydrogen inlet of the hydrogen storage system through a hydrogen transmission pipeline, and the hydrogen outlet of the hydrogen storage system is connected to the hydrogen inlet of the methanol synthesis system through a hydrogen transmission pipeline;

[0025] The methanol outlet of the methanol synthesis system is connected to the methanol inlet of the methanol storage system through a methanol delivery pipeline, and the methanol outlet of the methanol storage system is connected to the fuel inlet of the coke oven heating system through a methanol delivery pipeline.

[0026] Furthermore, the hydrogen storage system is provided with a hydrogen spherical tank for hydrogen buffer storage.

[0027] Furthermore, the methanol storage system is provided with a methanol vertical tank for methanol buffer storage.

[0028] The system for reducing carbon dioxide emissions during a coking production process described in the present invention works as follows:

[0029] 1) The coke oven flue gas generated after combustion in the coke oven heating system first enters the flue gas desulfurization and denitrification system to remove NOx and SO2 in the coke oven flue gas;

[0030] 2) The coke oven flue gas after desulfurization and denitrification enters the CO2 absorption and analysis system to separate the CO2 in the coke oven flue gas. The separated CO2 enters the methanol synthesis system, and the remaining flue gas after CO2 removal is discharged through the chimney;

[0031] 3) The wind power / photovoltaic power generation system converts wind energy or light energy into electrical energy, part of which is sent to the water electrolysis hydrogen production system and the other part is sent to the energy storage system;

[0032] 4) When the amount of electricity directly delivered by the wind power / photovoltaic power generation system to the water electrolysis hydrogen production system is less than the set value, the electricity stored in the energy storage system is released and sent to the water electrolysis hydrogen production system, thereby achieving continuous and stable operation of the water electrolysis hydrogen production system;

[0033] 5) The water electrolysis hydrogen production system uses the electricity transmitted by the wind power / photovoltaic power generation system or the energy storage system to realize water electrolysis hydrogen production through the electrolyzer, and the hydrogen is purified and then sent to the hydrogen storage system;

[0034] 6) The hydrogen storage system buffers and stores the hydrogen sent from the water electrolysis hydrogen production system and then sends it to the methanol synthesis system;

[0035] 7) In the methanol synthesis system, CO2 sent from the CO2 absorption and desorption system reacts with hydrogen sent from the hydrogen storage system under the action of a catalyst, and the generated methanol is sent to the methanol storage system;

[0036] 8) The methanol storage system buffers and stores the methanol delivered by the methanol synthesis system and then sends it to the coke oven heating system.

[0037] The utility model captures CO2 in coke oven flue gas and converts it into methanol fuel. Methanol fuel is an internationally recognized green and clean fuel (methanol is an oxygen-containing compound). Using methanol as the fuel for the coke oven heating system can significantly reduce carbon emissions from the coking production process compared with the fuel used in conventional coke oven heating systems (the CO2 removal rate in the coke oven flue gas is ≥85%, and the CO2 concentration in the remaining flue gas can be as low as below 50PPM), thereby effectively reducing the emission of CO2 in the coke oven flue gas.

[0038] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A system for reducing carbon dioxide emissions during a coking production process, characterized in that: Including coke oven heating system, flue gas desulfurization and denitrification system, CO2 absorption and analysis system, methanol synthesis system, wind power / photovoltaic power generation system, energy storage system, water electrolysis hydrogen production system, hydrogen storage system and methanol storage system; The coke oven flue gas outlet of the coke oven heating system is connected to the flue gas inlet of the flue gas desulfurization and denitrification system through a coke oven flue gas transmission pipeline, the flue gas outlet of the flue gas desulfurization and denitrification system is connected to the flue gas inlet of the CO2 absorption and desorption system through a flue gas pipeline, the CO2 gas outlet of the CO2 absorption and desorption system is connected to the CO2 gas inlet of the methanol synthesis system, and the residual flue gas outlet of the CO2 absorption and desorption system is connected to the chimney; The power supply outlet of the wind power / photovoltaic power generation system is connected to the power supply inlet of the water electrolysis hydrogen production system through a cable on one side, and is connected to the power supply inlet of the energy storage system on the other side; the power supply outlet of the energy storage system is connected to the power supply inlet of the water electrolysis hydrogen production system; the hydrogen outlet of the water electrolysis hydrogen production system is connected to the hydrogen inlet of the hydrogen storage system through a hydrogen transmission pipeline, and the hydrogen outlet of the hydrogen storage system is connected to the hydrogen inlet of the methanol synthesis system through a hydrogen transmission pipeline; The methanol outlet of the methanol synthesis system is connected to the methanol inlet of the methanol storage system through a methanol delivery pipeline, and the methanol outlet of the methanol storage system is connected to the fuel inlet of the coke oven heating system through a methanol delivery pipeline.

2. The system for reducing carbon dioxide emissions during a coking production process according to claim 1, characterized in that: The hydrogen storage system is provided with a hydrogen ball tank for hydrogen buffer storage.

3. The system for reducing carbon dioxide emissions during a coking production process according to claim 1, characterized in that: The methanol storage system is provided with a methanol vertical tank for buffering and storing methanol.

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