Coke oven flue gas desulfurization technology and system

Abstract

The invention discloses a coke oven flue gas desulfurization technology and system and mainly aims to reduce temperature drop of flue gas in a desulfurization process so as to meet the hot standby requirement of a chimney. According to the coke oven flue gas desulfurization technology and system, a sodium-alkali solution is taken as a desulfurizing agent, the atomized sodium-alkali solution is subjected to a reaction with SO2 in flue gas, and sulfite is generated, dried with the flue gas and recovered by a dust collector; the recovered desulfurized dust is regenerated by the aid of a Ca(OH)2 solution, desulfurized gypsum and a sodium-alkali regenerated solution are obtained, and the sodium-alkali regenerated solution returns to a desulfurization system for circulating desulfurization. With the adoption of the coke oven flue gas desulfurization technology and system, investment and operation cost of coke oven flue gas desulfurization can be remarkably reduced, the outlet flue gas temperature of desulfurization equipment is increased, the hot standby requirement of the chimney can be met without reheating, and meanwhile, the problems of scaling, difficulty in sodium-alkali regeneration and the like of a wet double-alkali method are solved.

Description

technical field [0001] The invention relates to a coke oven flue gas desulfurization process and system. Background technique [0002] As one of the main air pollutants, sulfur dioxide has always been the focus of my country's emission reduction work. With the continuous improvement of environmental protection legislation and the increasingly stringent environmental protection standards, certain progress has been made in reducing sulfur dioxide emissions. appear. However, in the non-electrical industries such as coke oven smelting, iron and steel metallurgy, building materials and cement, where the emission reduction work started late, the emission reduction situation of air pollutants is still very serious. Especially for flue gas emissions from coke oven smelting, most companies have not taken any emission reduction measures. According to the requirements of "Coking Chemical Industry Pollutant Emission Standard" (GB16171-2012), the emission concentration of sulfur dioxi...

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Problems solved by technology

[0004] In response to these problems, CN103877856A proposes to use coke produced by coking enterprises to reduce SO in flue gas 2 Adsorption removal, this method can ensure the purification of coke oven flue gas under the condition of lower flue temperature drop, but because the coke produced by the coking plant has a small specific surface area and limited adsorption capacity, it needs to continuously replenish a large amount of fresh coke to Satisfy SO 2 emission requirements, and the SO adsorbed by the spent coke in the downstream utilization process 2 Will still be released, just implemented SO 2 The transfer of emissions does not really achieve SO 2 emission reduction

CN101874975 discloses a double-alkali semi-dry desulfurization process, but this method only mixes a certain proportion of sodium hydroxide in the absorbent of the conventional lime dry desulfurization process, which can improve the desulfurization efficiency to a certain extent, but because sodium-alkali cannot regeneration, also significantly increases operating costs

At the same time, this method still mainly uses calcium alkali as the absorbent, and it is difficult to achieve a lower flue gas temperature drop while satisfying the desulfurization efficiency.

At the same time, the existing mature double-alkali desulfurization process is a wet process, the flue gas outlet temperature is low, and calcium sulfate deposition and blockage are prone to occur during the slurry circulation process, which also cannot meet the desulfurization requirements of coke oven flue gas

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