System and method for purifying product gas of urea hydrolysis

Abstract

The invention discloses a system and a method for purifying produced gas of urea hydrolysis. The system comprises a urea hydrolysis reactor, a dehydration device, a CO2 absorption and desorption device and an ammonia supply mother pipe, wherein a product gas outlet and a heat tracing pipeline are arranged on the urea hydrolysis reactor; the dehydration device comprises at least two dehydration units which are connected in parallel, and an electric heating assembly is arranged in a gap between an outer dehydration shell and an inner dehydration shell; a gas drying agent is arranged in the inner dehydration shell, and the side wall is connected with a product gas inlet pipeline, a product gas outlet pipeline and a water vapor outlet pipeline; the CO2 absorption and desorption device comprises two CO2 removal units and a gas cooling device; the gas channels of the two CO2 removal unit are respectively connected with the gas cooling device and then communicate with the inner absorption shell of the other CO2 removal unit; and the inner absorption shells of the two CO2 removal unit respectively communicate with the ammonia supply mother pipe through corresponding product gas outlet pipelines in the inner shells.

Description

technical field [0001] The invention relates to the field of preparation of a flue gas denitrification reducing agent, in particular to a gas purification system and method for a urea hydrolysis product. Background technique [0002] At present, the denitrification system of coal-fired thermal power plants mostly adopts the selective catalytic reduction (SCR) process. The reducing agent required for the denitrification reaction is ammonia gas, which can be obtained from liquid ammonia, ammonia water and urea. Liquid ammonia and ammonia water are evaporated to produce ammonia. These two ammonia production systems have simple processes, low initial investment, low operating costs and maintenance costs, and are easy to control. However, since liquid ammonia or ammonia water is a toxic and dangerous chemical, and the power plant flue gas The large consumption and storage of liquid ammonia or ammonia water have formed a major source of danger, and the safety risk is very high. I...

AI Technical Summary

Problems solved by technology

The current heat tracing methods for the ammonia supply main pipe of the hydrolyzer include steam half-pipe heat tracing, steam jacketed pipe, electric heat tracing, etc. No matter which heat tracing method is used, it will consume a lot of energy. Resulting in higher quality of heat tracing and insulation construction

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