High-ammonia-content sulfur-content tail gas treatment process

Abstract

The invention discloses a high-ammonia-content sulfur-content tail gas treatment process. According to the process, high-ammonia-content tail gas, high-sulfur-content tail gas and combustion air are preheated by a preheater and are introduced into a thermal oxidation furnace, then are subjected to a thermal oxidation reaction at high temperature, most of NH3 in the tail gas can be converted to N2, H2S, COS, S and CO are oxidized to SO2, CO2 and H2O; high temperature gas at an outlet of the thermal oxidation furnace passes through a waste heat recovery system, after the waste heat is recovered, the flue gas after waste heat recovery is introduced into a subsequent SCO reactor, NOx is subjected to catalytic reduction to obtain N2, and the unoxidized H2S, HCN and NH3 are converted to SO2, carbon dioxide, nitrogen and water, wherein, the reaction temperature of the thermal oxidation furnace is 600-1800 DEG C, the operation pressure of the thermal oxidation furnace is 0-30 Kpa; the reaction temperature of the SCO reactor is 300-750 DEG C, and the operation pressure of the SCO reactor is 0-25 Kpa. The treatment process is used for processing the high-ammonia-content sulfur-content tail gas discharged from an industrial process.

Description

technical field [0001] The invention relates to a treatment process for tail gas containing high ammonia and sulfur content, which is a treatment method for waste gas containing sulfur and ammonia discharged from industrial processes; in particular, it relates to the thermal oxidation treatment of high ammonia content tail gas and the treatment of sulfur and NO x Tail gas selective catalytic treatment process. Background technique [0002] The use of the three major fossil raw materials of petroleum, coal and natural gas will be accompanied by the generation of sulfur compounds, SO 2 、H 2 S, COS, mercaptan, SO 3 Various sulfur compounds will pollute the environment. In the atmosphere, sulfur dioxide will be oxidized to form sulfuric acid mist or sulfate aerosol, which is an important precursor of environmental acidification. In some petrochemical and coal chemical processes, not only high-sulfur tail gas, but also high-ammonia tail gas will be generated at the same time....

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Problems solved by technology

Existing problems include: the incinerator operates at a high temperature above 1250°C, when the H in the acid gas 2 The S content is less than 85%, and a large amount of fuel needs to be supplemented to maintain the furnace temperature, resulting in increased operation difficulty and increased operating costs; 2 If present, COS and CS will be generated 2 and other by-products that are difficult to remove; HCN in the tail gas can hardly be removed by thermal incineration; at high temperature, some NH 3 converted into NO x , considering the follow-up NO x treatment, the traditional SCR denitrification process ensures NO x While meeting emission standards, it is difficult to avoid ammonia escape

The disadvantage is that the system investment is high and the operating cost is high; hydrogen needs to be added, and the system safety requirements are high; generally, the quenching tower uses ammonia injection or alkali injection to eliminate corrosion, and the alcohol amine absorption system is easy to foam and the operation is complicated; The HCN in the

[0013] Although the existing technologies have their own advantages and disadvantages, in the comprehensive treatment of high-ammonia and sulfur-containing tail gas, the tail gas does not meet the standard, H 2 S, NH 3 , HCN, NO x Difficult to remove, refueling increases operating costs, and economic benefits are not obvious, etc.

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