Method for recovering hydrogen and ammonia from synthetic ammonia purge gas by membrane separation-rectification integrated technology and device

Abstract

The invention relates to a method for recovering hydrogen and ammonia from synthetic ammonia purge gas by membrane separation-rectification integrated technology and a production device thereof, and the method comprises treatment in the following three units in order: 1) treatment in a high pressure purge gas membrane separation hydrogen recovery unit; 2) treatment in a low pressure purge gas membrane separation hydrogen recovery unit; 3) treatment in an ammonia water rectification unit. The unit 1) and the unit 2) recover hydrogen and generate ammonia water, and the unit 3) recovers liquid ammonia form the ammonia water, and recycles the rectification kettle liquid as water for ammonia absorption. The invention provides a hydrogen ammonia recovery integrated solution scheme for synthetic ammonia industry; compared with hydrogen ammonia ammonia recovery by traditional simple constant pressure recovery methods, membrane separation methods or ammonia water rectification methods, the method of the invention overcomes the problem of incomplete recovery coverage area and the problem of harmful waste liquid waste gas discharge; during hydrogen ammonia recovery, the discharge of ammonia containing waste water is reduced to zero; and the target of maximization of economic benefits and environmental protection benefits is realized.

Description

technical field [0001] The invention belongs to the field of synthetic ammonia industry, and in particular relates to a method and a device for recovering hydrogen and ammonia from synthetic ammonia purge gas by using membrane separation-rectification integration technology. Background technique [0002] The synthetic ammonia industry is a basic chemical industry and occupies a very important position in the chemical industry. Synthetic ammonia is widely used in the production of chemical fertilizers, various ammonium salts, nitric acid, explosives, plastics, synthetic fibers, paints, photosensitive materials and other products. At present, the annual output of synthetic ammonia in China is more than 50 million tons, accounting for about one-third of the world's output. With the global population reaching 7 billion people and showing a rapid growth trend, the demand for increasing crop production and expanding the green area of ​​the environment determines the increase in t...

AI Technical Summary

Problems solved by technology

However, there is a common problem in these three stages that has not been resolved, that is, the efficient recycling of ammonia and the discharge of ammonia water

For synthetic ammonia plants, the production of ammonium bicarbonate is uneconomical, and the urea analysis system often cannot handle so much ammonia water, and the recycled ammonia water has become a burden for the enterprise

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