Method for producing ammonium nitrate by ammonium-containing waste gas

Abstract

The invention discloses a technological method for producing ammonium nitrate by ammonium-containing waste gas. The technological method of the invention comprises the steps of ammonium acid neutralisation, evaporation and condensation, and treatment and recovery of neutralisation wastewater. The ammonium acid neutralisation reaction in the invention generates ammonium nitrate and discharges lotsof heat synchronously, the heat can be moved by a big enough internal circulating system in a neutraliser such that the neutralisation reaction between the ammonium-containing waste gas and nitric acid can be performed normally without causing local overheat and increasing explosion risk. The neutralisation heat generated in the neutralisation reaction can be effectively used so as to greatly reduce the consumption of steam in the whole production process. The neutralisation wastewater can be completely recovered after the treatment by an ion exchanger filled with ion exchange resin. The technology of the invention can completely recover and use the ammonium in the ammonium-containing waste gas and adequately use the neutralisation heat generated in the neutralisation reaction. The energyconsumption is low and the added value of the product is high. The invention can save 100kg of steam in the production of 1000kg of molten ammonium nitrate.

Description

technical field [0001] The invention relates to the technical field of ammonia-containing waste gas treatment, in particular to a process for producing ammonium nitrate by using ammonia-containing waste gas. Background technique [0002] The ammonia-containing waste gas of chemical enterprises mainly includes the vent gas of the synthetic ammonia production unit, the vent gas of the liquid ammonia storage tank, and the ammonia-containing tail gas of the melamine production unit. The purge gas of synthetic ammonia mainly contains H 2 , N 2 , NH 3 and a small amount of inert gas, where H 2 It accounts for about 60%; the vent gas of the liquid ammonia storage tank mainly contains a large amount of NH 3 and a small amount of inert gas; melamine tail gas is a gas containing about 70% NH 3 , 30% CO 2 And a small amount of ammonia-containing waste gas of liquid and solid substances, the liquid and solid substances are mainly organic impurities such as urea, cyanuric acid, hea...

AI Technical Summary

Problems solved by technology

The first method has low energy consumption but low product added value

In the second method, the process technology of ammonia-carbon separation is complicated, the process flow is long, and the equipment investment is large. The ammonia contained in the separated carbon dioxide is difficult to return to the process production device for use, and direct discharge will cause great economic waste. , and does not meet the requirements of environmental protection regulations

The third method, when combined with other existing urea plants, will increase the water volume of the system in large quantities, causing an increase in the water-carbon ratio in the urea synthesis tower, resulting in a decrease in the conversion rate of carbon dioxide in the urea synthesis tower and increased consumption

Moreover, although the products obtained by the latter two methods have high added value, the energy consumption is high, and each ton of liquid ammonia needs to consume 200 to 250 Kwh of electricity and consume 5.0 to 5.5 tons of steam at 1.0 MPa (G).

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