化学吸收法燃烧后碳捕集技术有着对电厂改造程度小、对烟气中二氧化碳选择性高的优点，被认为是目前最有可能大规模应用的碳捕集技术之一，但是其最大的问题在于能耗高。本文从吸收剂吸收特性和流程优化的角度分析了它们对碳捕集系统能耗的影响。本文建立了基于MEA溶液的传统二氧化碳捕集流程的模型，并且通过与实际数据对比进行了模型验证。研究了关键流程参数对系统能耗的影响。研究发现，系统的再生热耗随吸收剂溶质浓度的增加、贫/富液换热器冷端温差的减小和解吸塔压力的增加而减小，而系统的再生热耗随贫液碳负载的增加而存在最小值。计算得到，基于MEA溶液的传统碳捕集流程的最小再生热耗为3.42 MJ/kg CO2。研究了吸收剂吸收特性对于传统流程的再生热耗、节能潜力和设备设计尺寸的影响。传统流程的再生热耗随吸收剂吸收热的减小、循环容量的增大和吸收容量的增大而降低；传统流程节能潜力也随吸收剂吸收热的减小、循环容量的增大和吸收容量的增大而降低。二级反应动力学常数决定了吸收塔设计尺寸，研究发现，基于PZ溶液的吸收塔设计高度是基于MEA溶液的0.5倍。研究了吸收剂吸收特性对于具体的流程优化方案的能耗、节能效果的影响。研究发现，流程优化方案的能耗均随吸收剂吸收热的减小、循环容量的增大和吸收容量的增大而降低。吸收塔中间冷却、富液分流和解吸塔中间加热的节能效果随吸收剂吸收热的减小、循环容量的增大和吸收容量的增大而降低；贫液蒸汽压缩对低吸收热、低循环容量、低吸收容量的吸收剂节能效果较大；多级压力解吸对高吸收热、低循环容量、低吸收容量的吸收剂节能效果较大；而解吸塔顶出口气体压缩的节能效果不明显。建立了燃煤电厂碳捕集系统经济性的模型，得到了550 MW燃煤电厂的二氧化碳捕集系统的新型方案，新型方案为基于AMP/PZ混合溶液和吸收塔中间冷却、富液分流和贫液蒸汽压缩的组合优化流程的碳捕集系统，其二氧化碳捕集成本为163.95元/t CO2，相比传统方案下降了15.6%。
The post-combustion carbon capture based on chemical absorption owns the advantages on small transformation of power plant and high selectivity to carbon dioxide in flue gas. It is considered to be one of the most likely carbon capture technologies for large-scale application. However, its inherent drawback is the high energy consumption. In this work, the impact of absorbent absorption characteristics and process modifications on energy consumption of CO2 capture system is analyzed.A model of the conventional CO2 capture process based on aqueous MEA is developed. It is verified by comparison between the model results and the actual data. The influence of key process parameters on energy consumption is studied. The regeneration heat consumption decreases with the increase of absorbent solute concentration, the decrease of the cold end temperature approach of rich/lean solvent heat exchanger and the increase of stripper pressure. The regeneration heat consumption has a minimum value with the increase of lean solvent carbon loading. The minimum regeneration heat consumption of the conventional CO2 capture process based on aqueous MEA is 3.42 MJ / kg CO2.The effect of absorbent absorption characteristics on regeneration heat consumption, energy saving potential and equipment design size of the conventional process is studied. The regeneration heat consumption of the conventional process decreases with the decrease of absorption heat, the increase of cyclic capacity and the increase of absorption capacity. The energy saving potential of conventional process also decreases with the decrease of absorption heat, the increase of cyclic capacity and the increase of absorption capacity. The second-order reaction kinetic constant determines the size of absorber. It is found that the design height of absorber based on aqueous PZ is 0.5 times as that based on aqueous MEA.The effect of absorbent absorption characteristics on energy consumption and energy saving effect of the specific process modification schemes is studied. It is found that the energy consumption of the process modification schemes decreases with the decrease of absorption heat, the increase of cyclic capacity and the increase of absorption. The energy-saving effect of the intercooling scheme, the rich split scheme and the intermediate heating scheme decreases with the decrease of absorption heat, the increase of cyclic capacity and the increase of absorption. The lean vapor compression scheme has a greater energy-saving effect on the absorbent with lower absorption heat, lower cyclic capacity and lower absorption capacity. The multi-pressure stripper scheme has a greater energy-saving effect on the absorbent with higher absorption heat, lower cyclic capacity and lower absorption capacity. The energy saving effect of stripper overhead compression scheme is not obvious.An economic model of the CO2 capture system applied for coal-fired power plant is developed. A new scheme of carbon dioxide capture system in 550 MW coal-fired power plant is obtained. The new scheme is a carbon capture system based on the AMP/PZ solvent solution and the process integration of the intercooling, rich split, and lean vapor compression. The CO2 capture cost of the new scheme is 163.95 yuan/ kg CO2, which is 15.6% lower than that of the traditional scheme.
