钙基吸收剂捕集火电机组烟气中CO_2的热力性能分析

Thermodynamic Analysis of CO_2 Capture from Coal-fired Flue Gas Using Ca-based Sorbent

针对燃煤火电机组减排CO2的问题,以某1 000MW超临界机组为例,建立了钙基吸收剂循环煅烧/碳酸化法捕集CO2的系统流程,得到了CO2捕集率与弛放率、钙碳物质的量比和气固分离效率等参数的关系,基于Aspen Plus软件分析了关键参数对系统性能的影响.结果表明:捕集90%CO2和100%SO2使得机组的发电热效率比设计值降低了8.73个百分点;随着弛放率的提高或气固分离效率的降低,固体循环物料质量流量、煅烧能耗和发电热效率均下降;随着CO2捕集率的提高,固体循环物料质量流量和煅烧能耗呈逐渐增大的趋势,但发电热效率则降低.

To reduce the CO2 emission from coal-fired power plants, a 1 000 MW supercritical power unit was taken as an example, for which a CCCR （cyclic calcination/carbonation reaction） flow chart was built up to capture CO2 from the flue gas with Ca-based sorbents, so as to obtain the relationship among the CO2 capture efficiency, the CO2 purge percentage, the Ca/C molar ratio and the gas-solid separation efficiency. Effects of above key parameters on thermodynamic performance of the system were analyzed simultaneous- ly by the help of Aspen Plus software. Results show that the thermal efficiency for power generation will drop by 8.73 percentage points, compared with the design value, under the capture efficiency of 900//oo CO2 and 100% SO2; all the circulation solids flow, calcination energy consumption and thermal efficiency for power generation reduce with rising purge percentage and decreasing gas solid separation efficiency; with