SCR烟气脱硝尿素热解和水解技术经济性分析

尿素由于运输储存安全方便和对环境无害的特点，成为燃煤电厂SCR烟气脱硝还原剂液氨的可靠替代品。选择合适的尿素制氨技术是SCR烟气脱硝液氨改尿素工程的关键环节。通过工程建模对比分析采用尿素热解和尿素水解工艺的投资费用和运行成本，采用热力学方法分析尿素制氨系统能耗水平。结果表明：尿素水解投资略高于尿素热解，但其运行成本较低，技术经济性更优；尿素热解运行成本高的原因主要在于尿素转化率偏低，且采用高品质电能作为热源。

Economic Analysis of Pyrolysis and Hydrolysis for SCR Flue Gas Denitrification Urea

Because of its safety and convenience for transportation and storage in addition to its harmlessness to environment, urea has become a reliable substitute for liquid ammonia, a reducing agent for SCR flue gas denitrification in coal-fired power plants. The key part of the project to switch to urea from liquid ammonia is how to select suitable urea technology. In this paper, the investment cost and operation cost of urea pyrolysis process and urea hydrolysis process are analyzed through engineering modeling. The energy consumption level of urea ammonia production system is also studied by using thermodynamic method. The results show that the cost of urea hydrolysis is slightly higher than that of urea pyrolysis, but the operation cost is lower and the technical economy performance is better. The main reason for the high operation cost of urea pyrolysis is found out to be the low conversion rate of urea and the application of high quality electric energy as heat source.