三聚氰胺尾气低温精馏工艺可行性研究

Feasibility Analysis on Cryogenic Distillation Process of Melamine Exhaust

从反应速率、化学平衡两方面对氨和二氧化碳低温条件下生成氨基甲酸铵反应进行计算,论证一种低温精馏三聚氰胺尾气工艺的可行性。结果表明,在-20～160℃范围内,反应为快速反应且反应速率随温度变化不明显;温度越低,反应不可逆性越大;温度降低到92.6℃,开始有氨基甲酸铵生成,进一步降低温度至60℃,二氧化碳转化率达到99.96%;采用改变三胺尾气总压力或改变原料气组成的方式不能解决低温精馏过程出现的反应问题;低温精馏工艺不适用于三胺尾气碳氨分离。

Reaction rate and chemical balance about the formation of ammonium carbamate produced from ammonia and carbon dioxide at low temperatures were calculated to demonstrate the feasibility of a cryogenic distillation process for triamine exhaust. Results showed that the reaction was fast and the reaction rate did not change significantly with temperature in the range of -20 ℃ to 160 ℃. The lower the temperature, the more irreversible the reaction was. Ammonium carbamate began to generate when temperature decreased to 92.6 ℃ and the conversion rate of C02 was up to 99.97% when temperature decreased to 60 ℃. Neither changing the pressure of triamine exhaust nor changing the gas composition could avoid the reaction problems in cryogenic distillation process, so the process was not feasible for carbon and nitrogen separation of triamine exhaust.