Improved method for resolving ammonium salt in acrylonitrile non-ammonium-sulfate process

Abstract

The invention relates to an improved method for resolving an ammonium salt in an acrylonitrile non-ammonium-sulfate process and is mainly used for solving the problem that the energy consumption is high during ammonium salt resolving in the prior art. According to the technical scheme, the method comprises the following steps: (1) enabling a reaction gas I and a low-ammonium absorption liquid I to come into contact with unreacted ammonium in a quenching tower so as to obtain a high-ammonium absorption liquid II and a ammonium-free reaction gas II; (2) performing steam stripping on the high-ammonium absorption liquid II in a stripping tower and then performing oil-water separation so as to obtain a high-ammonium absorption liquid III; heating the high-ammonium absorption liquid III in a resolving tower and performing the steam stripping so as to obtain an ammonium gasflow III and an ammonium dihydrogen phosphate crystal IV; dissolving the low-ammonium absorption liquid V; returning the absorption liquid V into the quenching tower for absorbing the unreacted ammonium; and (3) performing rectification separation on the ammonium gasflow III in an ammonium rectification tower so as to obtain ammonium IV with high purity; and returning the ammonium IV into an ammonium oxidation reactor and reacting. Thus, the problem in the prior art is solved well. The method provided by the invention can be applied to an industrial device of acrylonitrile.

Description

technical field [0001] The invention relates to an improved method for ammonium salt analysis of acrylonitrile-free ammonium sulfate process. Background technique [0002] During the production of acrylonitrile, about 10% of unreacted ammonia needs to be absorbed and separated from the reactant stream. Although there are techniques to reduce the ammonia content at the reactor outlet, there is still a large amount of unreacted ammonia. The current production process is mainly to absorb unreacted ammonia through sulfuric acid washing, and the ammonium sulfate wastewater is directly injected into the deep well for treatment, or the crystalline ammonium sulfate is recovered through the ammonium sulfate recovery section, or the ammonium sulfate is incinerated to produce SO 3 , and then absorbed to make sulfuric acid back to the system for recycling. There are also some patents that recover unreacted ammonia through the neutralization of phosphoric acid, ammonium dihydrogen phos...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is the problem of high energy consumption and high material consumption caused by the use of wet oxidation in the prior art, and a new improved method for ammonium salt analysis of acrylonitrile-free ammonium sulfate process is provided

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