煤直接化学链气化合成尿素过程建模与性能分析

Modeling and Performance Analysis of Coal-to-urea Process by Coal Direct Chemical Looping Gasification

本文针对传统煤制尿素过程碳利用率低及二氧化碳捕集能耗高的问题,提出了煤直接化学链气化合成尿素的新工艺。本文对新工艺关键单元进行建模、模拟和性能分析。新工艺中CO_(2)、H2和N2分别来自于化学链技术的燃烧反应器,水蒸气反应器和空气反应器,避免了高能耗的空分单元和气体分离单元,H2和N2用于合成氨,氨进一步与CO_(2)合成尿素。采用碳利用率和二氧化碳捕集能耗分析新艺的技术性能,生产成本和投资回收期分析其经济性能。结果表明煤直接化学链气化合成尿素工艺碳利用率为30.11%,相比于传统煤制尿素提高约7%,二氧化碳捕集能耗下降了97.04%。新工艺单位尿素成本相比传统工艺下降了12.18%,投资回收期缩短了4年。

In view of the low carbon utilization efficiency of coal-based urea and the high energy consumption of carbon dioxide capture,a novel process for the chemical direct looping gasification of coal to synthesize urea is proposed.The key units of the new process are modeled,simulation and analyzed.CO2,H2,and N2 come from fire reactor,steam reactor and air reactor respectively,avoiding the high energy consumption of air separation unit and gas separation unit.H2 and N2 are used to synthesize ammonia,and ammonia is further combined with CO2 to synthesize urea.The performance of the two processes is analyzed and compared using technical indicators such as carbon utilization and carbon dioxide capture energy consumption,and economic indicators with production cost and payback period.The results show that the carbon utilization of the chemical direct looping gasification of coal to synthesize urea is 30.11%,which is about 7% higher than that of traditional coal-based urea,the energy consumption of carbon dioxide capture drop by 97.04%.The production cost of the new process is 12.18% lower than that of the conventional process,and payback period shortened by 4 years.