Desulfurization purification method for blast furnace gas

Abstract

The invention discloses a desulfurization purification method for blast furnace gas. The method comprises the steps that S1, the blast furnace gas is dedusted through a dry-method cloth bag dedustingdevice and then enters an organic sulfur conversion device, and organic sulfur is converted into H2S; S2, H2S enters a blast furnace top gas recovery turbine unit for recycling pressure energy and hotenergy; S3, the cooled blast furnace gas enters a wet-method desulfurization device for removing hydrogen sulfide again and then enters all user units. According to the method, based on the temperature and pressure of the blast furnace gas, organic sulfur conversion is conducted, after the blast furnace gas passes through the blast furnace top gas recovery turbine unit (TRT), the temperature of the blast furnace gas is lowered, H2S removal is conducted, and sulfide in the blast furnace gas is removed. Recycling of pressure energy and hot energy of the blast furnace gas by the blast furnace top gas recovery turbine unit is not influenced.

Description

technical field [0001] The invention relates to the technical field of blast furnace gas purification, in particular to a blast furnace gas desulfurization purification method. Background technique [0002] Blast furnace ironmaking is one of the important processes of modern iron and steel production. The reducing agents used in ironmaking blast furnaces are coke, coal, heavy oil, etc. The reducing agent CO is produced by air blast and provides high-temperature heat. Due to the high nitrogen content in the air, dilute CO in the reducing gas is removed, so the CO content in the blast furnace gas is low and the nitrogen content is high. Typical blast furnace gas contains CO: 24-26%; CO2 14-16%; H2 1-2%; CH4 0.3-0.8%; N2 56-59%. Calorific value: 3200-4000kj / Nm3; In addition, there are H2S, COS, SO2, SO3 and other sulfides in blast furnace gas. [0003] In the past ten years, with the widespread application of blast furnace gas dry bag dust removal + residual pressure turbine ...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a method for blast furnace gas desulfurization and purification aimed at the deficiencies of the prior art, aiming at the higher content of sulfide in the blast furnace gas and the inability of the existing wet scrubbing device behind the TRT device to remove organic sulfur, resulting in its Due to the shortage of SO2 content in flue gas after combustion, a blast furnace gas desulfurization process is proposed. The removal of H2S by lowering the temperature realizes the removal of sulfide in the blast furnace gas, and does not affect the recovery of the pressure energy and heat energy of the blast furnace gas by the residual pressure turbine power generation device

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