天然气制烯烃发电多联产系统的模拟与[火用]分析

Simulation and exergy analysis of natural gas-based polygeneration system for power and olefin production

以天然气为原料,构建全新天然气制烯烃发电多联产系统,实现制烃系统和联合循环发电系统的有机耦合.采用Aspen Plus模拟软件对该系统进行流程模拟,计算出各物流的火用值,并对各单元进行热力学分析.输入输出火用分析结果表明,当甲醇合成单元的未反应气全部循环时系统的火用效率最高,为53.5%.从系统的火用损失量来看,火用损主要发生在天然气制合成气和尾气发电单元,两者分别占系统总火用损的36.4%和42.1%.

In this paper, a novel natural gas polygeneration system for olefin and power production was proposed, which achieves the organic coupling of hydrocarbon system and combined cycle power generation system. The polygeneration system was simulation by Aspen Plus, and the exergy of each steams were calculated based on their entropy and enthalpy. The results of the exergy analysis indicate that the exergy efficiency of the system reaches a maximum, 53.5%, when all unreacted syngas is recycled back to the reactor in the methanol synthesis process. Exergy destruction mainly takes place in the gasification process and the power plant, which account for 36.4% and 42.1% of the whole exergy loss, respectively.