Desulfurization purification process of acidic water stripped ammonia gas

Abstract

The invention provides a desulfurization purification process of acidic water stripped ammonia gas. The main equipment include, along the ammonia gas flow direction, a heater, an H2S direct oxidation reactor, two parallel condensers or two condensers changeable in order, and two catalytic oxidation adsorption desulfurization towers capable of being connected in series and parallel. An H2S concentration on-line analyzer, an oxygen introduction pipe and a mixer are disposed in front of the heater. The H2S direct oxidation reactor is filled with a TiO2 based sulfur recovery catalyst, the catalytic oxidation adsorption desulfurization towers are filled with a catalytic oxidation adsorption desulfurizer prepared by modification of activated carbon. For the H2S direct oxidation reactor, the inlet air temperature is 190-210DEG C, the catalyst space velocity is 100-1000h<-1>, the bed temperature is 210-260DEG C, in the outlet ammonia gas, H2S is 200-500 microg / g NH3, and SO2 is smaller than or equal to 300 microg / g NH3. For the catalytic oxidation adsorption desulfurization towers, the inlet air temperature is 10-50DEG C, the desulfurizer space velocity is 10-100h<-1>, and in the outlet ammonia gas, H2S is less than or equal to 3 microg / g NH3, SO2 is less than or equal to 1 microg / g NH3, and organic sulfur is less than or equal to 1 microg / g NH3.

Description

technical field [0001] The invention relates to an ammonia purification process, in particular to a desulfurization purification process for stripping ammonia with acidic water. Background technique [0002] Acidic water produced by refineries, coal chemical plants, coal coking plants, coal-to-natural gas plants and some natural gas processing units, including acidic sewage and aqueous hydrogen treatment containing hydrogen sulfide and ammonia obtained from the circulating hydrogen treatment of some hydrogenation units, are separated by stripping, A stream of hydrogen sulfide and ammonia gas is obtained. [0003] Ammonia gas obtained by stripping and separating acidic water, such as ammonia gas obtained by single-tower stripping and condensing acidic sewage, usually contains about 1% H 2 S, generally most of the H will be washed by the cycle washing method 2 S is washed into ammonia water and returned to the stripper for re-separation, or made into NH 4 HS crystallization...

AI Technical Summary

Problems solved by technology

However, these ammonia desulfurization purification devices have NH 4 HS crystallization treatment control trouble, NH 4 HS solution or crystalline product has problems such as limited use due to impurity / color / odor, high energy consumption for cooling, high cost, poor operating environment, etc., and there are also problems with waste gas treatment and emission or waste agent treatment during the regeneration of fine desulfurizer; and , for a small amount of SO 2 , COS, organic sulfur such as mercaptan, thioether, CS 2 , and a small amount of volatile phenols, cyanides, hydrocarbons, no purification effect or the purification effect is not ideal, sometimes causing corrosion problems of subsequent main equipment such as compressors, and the quality of ammonia / liquid ammonia products such as chromaticity problems; fine desulfurization The composition of exhaust gas during agent regeneration is complex, containing organic sulfur, volatile phenols, and cyanides, which are difficult to treat and discharge

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