Technological method for co-production of ammonium bicarbonate through melamine tail gas

Abstract

The invention provides a technological method for co-production of ammonium bicarbonate through melamine tail gas and solves the problems that material balance is difficult, gas purification is substandard, the technology fluctuation range is large, and the like in a conventional production technology. The technological method comprises a co-production system formed by an ammonia tank, a main carbonizing tower, an auxiliary carbonizing tower, a bubble column, a thickener, a centrifugal machine and a mother liquor tank. The main carbonizing tower, the auxiliary carbonizing tower and the bubble column are operated, the temperature in the bubble column is kept to be 40-45 DEG C, and the tower boiling times are decreased; and the CO2 content in stronger ammonia water in the main carbonizing tower is controlled to be 120-124 mol / L, the yield of ammonium bicarbonate is determined according to the amount of the CO2, and materials are balanced, so that balance is achieved. According to the technological method, the main carbonizing tower, the auxiliary carbonizing tower and the bubble column are operated, the temperature in the bubble column is kept to be 40-45 DEG C, the yield of ammonium bicarbonate is determined according to the amount of the CO2 at the same time, and materials are balanced, so that balance is achieved. According to the technological method, an expected purpose is achieved, and carbonization process influences are relieved, so that an ammonia synthesis system can operate more stably.

Description

technical field [0001] The invention relates to the technical field of chemical production, in particular to a process for co-producing ammonium bicarbonate from melamine tail gas. Background technique [0002] my country's melamine co-production of soda ash, co-production of urea, and co-production of ammonium bicarbonate will cause problems such as difficulty in material balance and difficulty in meeting gas purification standards when the production capacity of melamine is too large. The melamine tail gas co-produced ammonium bicarbonate is connected to the synthetic ammonia gas purification process, because the NH in the tail gas 3 and CO 2 At the same time, while recovering the ammonia in the tail gas, it also absorbs a large amount of volatilized CO 2 Gas, so that the carbonation degree of the prepared concentrated ammonia water is as high as 140tt in summer and 130tt in winter, resulting in large fluctuations in the carbonization process, and the gas outlet purifica...

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Problems solved by technology

[0002] my country's melamine co-production of soda ash, co-production of urea, and co-production of ammonium bicarbonate, when the production capacity of melamine is too large, there will be problems such as difficulty in material balance and difficulty in meeting gas purification standards

The melamine tail gas co-produced ammonium bicarbonate is connected to the synthetic ammonia gas purification process, because the NH in the tail gas 3 and CO 2 At the same time, while recovering the ammonia in the tail gas, it also absorbs a large amount of volatilized CO 2 Gas, so that the carbonation degree of the prepared concentrated ammonia water is as high as 140tt in summer and 130tt in winter, resulting in large fluctuations in the carbonization process, and the gas outlet purification index CO 2 It is difficult to meet the standard, and when it is more serious, the concentrated ammonia water with high carbonization degree has no scar-dissolving effect in the carbonization auxiliary tower, and accelerates the formation of fine crystals, resulting in frequent carbonization scarring and boiling towers, which affects normal production and operation

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