醇胺法捕集燃煤烟气CO_2工艺模拟及优化

Process simulation and optimization of flue gas CO_2 capture by the alkanolamine solutions

使用Aspen Plus模拟了醇胺捕集燃煤烟气CO2的过程,考察了吸收剂用量、贫液负荷、再沸器负荷等操作因素对脱碳过程的影响,并比较了不同醇胺溶液吸收与解吸性能。结果表明:吸收剂用量及浓度越大、烟气CO2含量越低、吸收塔级数越多,则CO2脱除率越高;贫液负荷增大会降低溶剂吸收能力,在相同的CO2脱除率下,αlean为0.08时再生热耗最小;再沸器总负荷随CO2回收率增加而增大,但单位热耗却先降低而后略微增大,并在回收率80%附近取得最小值;各醇胺溶液吸收能力PZ>MEA>DEA≈AMP>MDEA,再生能力PZ>AMP>MEA,兼顾吸收与解吸,应将它们复配使用。

The absorption of CO2 in the flue gas by alkanolamine solution was simulated using the Aspen Plus software.The amount of absorbent,load of lean liquid and reboiler heat duty were used to evaluate the decarbonization process,and the absorptions and desorptions of different alkanolamines were compared.The results showed that the CO2removal rate increased with the absorbent amount and absorber progression,and lower flue gas CO2 concentration can improve the removal rate.The increase in lean liquid load reduced the absorbent absorption capacity.The minimum regeneration heat consumption was under the condition of αlean=0.08 at the same CO2 removal rate.The reboiler total duty increased with the increasing of the CO2 recovery,but the specific heat consumption first dropped and then increased slightly.The specific heat consumption obtains a minimum value around the CO2 recovery of 80%.The absorption capacities of various alkanolamine solutions were PZ MEA DEA≈AMP MDEA,degeneration capacities were PZ AMP MEA.These solutions should be mixed to achieve the best results in absorption and desorption.