大规模碳捕集电站贫液CO_2负载率优化研究

Optimization on Lean Solvent CO_2 Loading in Coal-fired Power Plants with Large-scale CO_2 Capture

针对燃煤电站CO2捕集能耗较高的问题,在统筹考虑大规模碳捕集燃煤电站汽水系统、脱碳单元和CO2多级压缩单元的相互影响下,对脱碳单元贫液CO2负载率进行了优化.结果表明:脱碳单元再生能耗随贫液CO2负载率的增大呈先减小后增大的趋势,且在贫液CO2负载率为0.26mol/mol时取得最小值;不同再生压力下,随着贫液CO2负载率的增大,脱碳单元的辅机泵功随之增大;在CO2捕集率保持不变的情况下,CO2压缩功几乎不随贫液CO2负载率的增大而发生变化;大规模碳捕集燃煤电站的供电效率随贫液CO2负载率的增大呈先提高后降低的趋势,在贫液CO2负载率为0.26mol/mol、再生压力为250Pa时取得最优值.

To solve the high energy consumption problem in CO2 capture of coal-fired power plants, an op- timization on lean solvent CO2 loading was conducted, based on a comprehensive consideration of the mutu- al effects among the steam-water system, decarbonization unit and the multistage CO2 compression unit. Results show that the regeneration energy consumption of decarbonization unit increases first and decreases later on with the rise of lean solvent CO2 loading, which reaches the minimum at the lean solvent CO2 load- ing of 0.26 mol/mol; the power consumption of auxiliary pump increases with the rise of lean solvent COz loading at different regeneration pressures; in the case that the CO2 capture ratio remains unchanged, the CO2 compression power consumption hardly changes with the lean solvent CO2 loading. For power plants with large-scale CO2 capture, the power supply efficiency increases first and decreases later on with the rise of lean solvent CO2 loading, and the optimum power supply efficiency can be obtained at the lean solvent CO2 loading of 0.26 mol/mol and the pressure of 250 Pa.