Method for recycling blast furnace gas

Abstract

The invention relates to a method for recycling blast furnace gas, and solves the problems of low additional value and poor using effect of the blast furnace gas because the advantages of the composition and chemical properties of the blast furnace gas cannot be brought into full play in the conventional method for recycling the blast furnace gas. The method comprises the following steps of: firstly, compressing the blast furnace gas and then allowing the compressed blast furnace gas to enter a temperature swing adsorption system for treatment to obtain purified blast furnace gas; secondly, pressurizing the purified blast furnace gas and then conveying the pressurized blast furnace gas to a pressure swing adsorption carbon extraction system for adsorption and purification to obtain carbon mixed gas; thirdly, pressurizing the rest blast furnace gas and then conveying the pressurized blast furnace gas to a pressure swing adsorption nitrogen extraction system to separate and recycle nitrogen; and finally, returning the rest blast furnace gas to a gas fuel system. The volume purity of the CO and CO2 mixed gas is over 95 percent and the mixed gas provides a synthesis air source for methanol and an organic synthesis and processing system; the volume purity of the nitrogen is over 99.5 percent, so that the problem that steel enterprises need the nitrogen with the volume purity of over 99 percent is solved; and the blast furnace gas has high additional value.

Description

technical field

[0001] The invention relates to a method for recycling blast furnace gas. Background technique

[0002] In iron and steel enterprises, blast furnace gas is a by-product produced in the ironmaking process, and its main components are: CO, CO 2 , N 2 、H 2 etc., in which the content of combustible components CO accounts for about 27%, H 2 The content of CO is about 2.7%. 2 , N 2 The contents accounted for 15%, 55% respectively, CH 4 Accounting for about 0.3%, the calorific value is low. Modern ironmaking production generally adopts large volume, high blast temperature, high smelting intensity, and high coal powder injection production technology. The use of these advanced production technologies improves labor productivity and reduces energy consumption, but the calorific value of the blast furnace gas produced Lower, increasing the difficulty of use. CO in blast furnace gas 2 , N 2 It does not participate in combustion to generate heat, nor can it sup...

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