Method for obtaining sulfur from sulfur compounds in coal chemical plant and electric power plant

Abstract

The invention relates to a method for obtaining sulfur from sulfur compounds in a coal chemical plant and an electric power plant. The method comprises the following steps of: (1) dedusting exhaust gas from a coal burning boiler system, and then concentrating the exhaust gas to improve the content of sulfur dioxide in the exhaust gas; (2) heating the concentrated exhaust gas through an exhaust gas preheater, then introducing the exhaust gas into a constant temperature selective reduction reactor, and enabling the exhaust gas to react under the action of a selective reduction catalyst by adding hydrogen as a reducing agent so as to generate elemental sulfur, wherein the chemical equation is H2+SO2=S+H2O (1), and the heat generated by the reaction is taken away by a cooling coil which is arranged in the constant temperature selective reduction reactor to ensure that the temperature in the constant temperature selective reduction reactor is maintained at around 210-240 DEG C; (3) removing liquid sulfur from the exhaust gas subjected to catalytic reduction through a sulfur condenser, and introducing the exhaust gas into a Claus reaction device, wherein the liquid sulfur enters a liquid sulfur tank; and (4) burning the sulfur and sulfide contained in the tail gas passing through the Claus reaction device by using a combustion furnace so as to convert the sulfur and sulfide into sulfur dioxide, delivering the sulfur dioxide into the boiler system to mix with a dedusted process gas, and concentrating the mixture, wherein the gas discharged during concentration is mainly carbon dioxide.

Description

technical field [0001] The invention relates to a method for extracting sulfur, in particular to a method for obtaining sulfur from sulfide-containing substances in coal chemical industry and power plants. Background technique [0002] Coal chemical industry refers to an industrial process in which coal is used as a raw material for chemical processing into gases, liquids and solids and further processed into a series of chemical products. The operation of coal chemical plant must rely on huge power consumption, so in the process of coal chemical construction, enterprises often need to invest in preparing to build their own power plants. [0003] In the process of coal gasification and hydrogasification, the sulfur element contained in coal and hydrogen generate hydrogen sulfide, and the gasification gas needs to be desulfurized and decarbonized to synthesize various chemical products. The current desulfurization and decarbonization is a physical method, such as Low tempera...

AI Technical Summary

Problems solved by technology

For the control of sulfur dioxide, the "limestone-gypsum method" or "ammonia desulfurization" process is currently used. This technology is widely used, but the treatment efficiency is not high, and the value of the recyclables is not high, which will cause secondary pollution.

[0005] At present, coal chemical enterprises use two sets of independent devices to treat the two kinds of polluting gases, which increases the total investment of the project. The total sulfur content of the power plant is relatively large, resulting in low economic value of the recovered products, and the total emission remains the same. High position, from the perspective of environmental protection and circular economy, not well reflected

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