Method for preparing hydrogen chloride and ammonia by utilizing ammonium chloride

Abstract

The invention discloses a method for preparing hydrogen chloride and ammonia by utilizing ammonium chloride, belonging to the field of recycling of ammonium chloride. The method comprises: excessive ammonium bisulphate is taken as reaction intermediate, firstly hydrogen chloride is prepared, ammonium sulphate and ammonium bisulphate which are obtained by reaction are added into an alcoholic solution, crystallization and separation are carried out, the separated ammonium sulphate is decomposed to obtain the ammonia and ammonium bisulphate, and the ammonium bisulphate reacts with the ammonium chloride to prepare hydrogen chloride gas. Ammonium bisulphate and alcoholic solvent can be recycled in the reaction process, excessive ammonium bisulphate can be added during the hydrogen chloride preparation process, thus not only the molten material system is ensured to have good fluidity and be fully contacted with the ammonium chloride, so as to speed up reaction, but also the ammonium chloride sublimation amount is reduced, the hydrogen chloride gas purity is improved, the intermediate separation step is added, the reaction speed and the reaction efficiency are improved, and the acid release reaction and the ammonium release reaction can be carried out stably.

Description

technical field [0001] The invention relates to a method for recycling ammonium chloride, in particular to a method for preparing hydrogen chloride and ammonia from ammonium chloride. Background technique [0002] Ammonium chloride is one of the two major products of the combined soda production process. In recent years, with the development of the soda ash industry, ammonium chloride has increased day by day. Due to the restrictions on the application of chemical fertilizers, it has been too late to find a suitable way out and there is a large surplus. It has become the bottleneck of the soda ash industry, and it is urgent to find a suitable utilization method. At the same time, the soda-making industry is inseparable from the synthetic ammonia industry. With the increase in energy prices in the process of synthetic ammonia production, the cost of the soda-making industry has also increased. If ammonium chloride is decomposed into hydrogen chloride and ammonia gas, not onl...

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Problems solved by technology

[0007] One is that the particle size of the raw material ammonium chloride is not properly controlled, resulting in a low conversion rate in the acid reaction process;

[0008] The 2nd, the reaction rate of releasing acid is low, causes ammonium chloride volatilization loss more, and then causes the hydrogen chloride gas that generates to be mixed with ammonium chloride and the purity is not high;

[0009] The third is that the reactions of the acid release process and the ammonia release process are all reversible reactions. In the process of preparing hydrogen chloride, ammonium sulfate has an inhibitory effect on the reaction. At the same time, in the process of preparing ammonia gas, ammonium bisulfate will also inhibit the reaction. , resulting in low reaction rate and reaction efficiency;

[0010] Fourth, in the process of releasing ammonia, due to containing more impurities such as ammonium bisulfate, there are more side reactions in the reaction, and the yield is low

[0011] In addition, the Chinese patent application with the application number 200710146327.X titled "A Method for Producing Ammonia and Hydrogen Chloride Gas from Ammonium Chloride" uses ammonium sulfate as a reaction intermediate to first produce ammonia gas and then hydrogen chloride gas Ammonium sulfate recycles, and this method still has the shortcoming of the patent application whose application number is 200710143384.2

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