Technology for synchronously denitrating ferrous oxalate on basis of flue gas desulfurization by aid of ammonia processes

Abstract

The invention discloses a technology for synchronously denitrating ferrous oxalate on the basis of flue gas desulfurization by the aid of ammonia processes. The technology includes allowing flue gas to flow into a concentration tower, carrying out contact reaction on the flue gas and concentrated liquid in the tower, delivering flue gas from the concentration tower into the middle of an absorption tower, allowing the flue gas to upwardly flow through a packing layer and a spray layer which are arranged on the upper portion of the absorption tower, carrying out reverse contact reaction on the flue gas and circulating absorption liquid and then exhausting the flue gas from flue gas outlets; leading out partial concentrated liquid from the bottom of the concentration tower, removing iron in the partial concentrated liquid by the aid of an iron removal system, then delivering the partial concentrated liquid into an ammonium sulfate crystallization system, enabling circulating absorption liquid sprayed out of the spray layer on the upper portion of the absorption tower to sequentially flow though the packing layer on the upper portion of the tower, carrying out reverse contact reaction on the circulating absorption liquid and the flue gas, enabling the circulating absorption liquid to flow into the bottom of the absorption tower, delivering the circulating absorption liquid to a photocatalytic regeneration reaction system, regenerating circulating absorption liquid, enabling the circulating absorption liquid to flow into a regeneration slurry tank, feeding ammonia water, oxalic acid and ferrous sulfate into the regeneration slurry tank, then delivering the ammonia water, the oxalic acid and the ferrous sulfate which are used as circulating absorption liquid into the spray layer on the upper portion of the absorption tower and spraying the circulating absorption liquid into the tower. The technology has the advantages of simplicity, low running cost and energy consumption, simplicity and convenience in control, good denitrating effects and high quality of byproducts.

Description

technical field [0001] The invention relates to a flue gas multi-pollutant collaborative treatment process in the field of environmental protection, in particular to a ferrous oxalate synchronous denitrification process based on flue gas ammonia desulfurization. Background technique [0002] The sintering process in the iron and steel smelting industry is SO 2 The main source of NOx and NOx, accounting for 98% and 50% of the total emissions of joint enterprises, the post-treatment technology of multi-pollutant coordinated control of sintering flue gas is still the key to pollution prevention and control. The characteristics of sintering flue gas are that the flue gas volume is large and changes greatly; the dust content is large; SO 2 Emissions and concentration vary greatly; smoke temperature is low and fluctuates greatly, generally 120-180°C, and low-temperature sintering technology can be as low as about 80°C; the composition is complex; the oxygen content and moisture c...

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Problems solved by technology

[0008] ⑴ Flue gas ammonia / Fe II The complexing agent regeneration process of EDTA compound synchronous desulfurization and denitrification adopts the iron filing method, the consumption of iron filings is large, and the concentration of iron ions in the absorption solution is too high, which not only increases the cost of iron removal, but also affects the quality of desulfurization and denitrification by-products

[0009] (2) When electrolytic regeneration is used, the investment in equipment is large, the power consumption of regeneration operation is large, the cost of regeneration operation is high, and the denitrification efficiency after regeneration is low, less than 50%

[0010] (3) Simultaneous denitrification complexing agent Fe II EDTA is expensive and consumes a lot, and the operation cost of synchronous denitrification is high

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