An integrated process for coke oven flue gas desulfurization and denitrification

Abstract

The invention discloses an integrated process for coke oven flue gas desulfurization and denitrification, comprising: after adjusting the temperature and humidity of coke oven flue gas to a set value, contacting with a desulfurization catalyst, and the desulfurization catalyst absorbs H in the flue gas 2 O, SO 2 and O 2 Catalyzed reaction to generate H 2 SO 4 ; The desulfurized coke oven flue gas is contacted with NO catalytic oxidizer, and part of NO is oxidized into NO 2 ; Mix the mixed gas of ammonia vapor and air with the coke oven flue gas after catalytic oxidation to obtain mixed coke oven flue gas; mix the mixed coke oven flue gas with low-temperature NH 3 ‑SCR denitration catalyst contacts for denitrification catalytic reaction, NH in the flue gas 3 , O 2 Catalytic reaction with NOx to generate N 2 and H 2 O; contact the coke oven flue gas after denitrification with ammonia adsorbent, the unreacted NH 3 Adsorbed by ammonia adsorbent to obtain clean tail gas. The process has the advantages of low cost, high efficiency, simple process flow and the like.

Description

technical field [0001] The invention relates to the technical field of flue gas purification, in particular to an integrated process for desulfurization and denitrification of coke oven flue gas. Background technique [0002] In recent years, smog has frequently appeared in most areas of our country. The country has paid more and more attention to environmental protection (air pollution), and the emission standards have become more and more stringent. The emission standards of coke ovens in some areas have required: SO 2 Less than 30mg / Nm 3 ;NOx less than 150mg / Nm 3 ; Dust less than 15mg / Nm 3 . Current SO in coke oven 2 , NOx content can not meet the emission requirements, so increasing coke oven flue gas denitrification and denitration devices is a problem that coking units must consider. [0003] At present, the integration of desulfurization and denitrification is mainly used in power plants, and the mainstream process route is: SCR+wet desulfurization. However, the...

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Problems solved by technology

[0011] b) If the SCR is arranged after desulfurization, the dust and SO 2 The concentrations are all low, but the flue gas temperature is low, which cannot meet the temperature requirements of alum-based catalysts, so it needs to be heated up, and a heating furnace is required, which consumes a lot of energy; even for low-temperature alum-based catalysts, it needs to reach a temperature above 260°C

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