关于吸收式碳捕集热力学机制的探索

Exploration of the Thermodynamic Mechanism of Absorption Carbon Capture

热再生吸收式碳捕集的传统认识难以揭示其热力学机制,一种新的认识是"热-化学能"转换中存在中间能量形式。本文从热力学碳泵概念出发,对吸收式碳捕集理想系统进行了解耦,其可视为"热机-碳泵"的热力学组合,探索了极限效率的表达,并采用第二定律效率作为评价参数对已有中试试验系统进行了性能水平探索。结果表明,理想循环性能系数仅取决于热源汇温度、碳源汇浓度;中试系统第二定律效率普遍低于20%。本文探索了热驱动的吸收式碳捕集热力学机制,为新型吸收剂设计提供了新思路。

Conventional thermal regeneration mode cannot reveal the thermodynamic mechanism of absorption-based CO2 capture technology.In this study,a developed understanding is proposed indicating that there is an intermediate energy form in the "heat-chemical energy" conversion process.Based on the concept of the thermodynamic carbon pump,an ideal absorption-based CO2 capture system is decoupled as the combination of " heat engine" and "carbon pump" thermodynamic processes.The expression of the ultimate efficiency is further explored,and the second law efficiency is used to describe the performance level of typical pilot-scale systems.Results show that the coefficient of performance of an ideal cycle only depends on the heat sink temperature and the carbon sink concentration.In general,the second law efficiencies of pilot-scale systems are lower than 20%.Overall,this paper explores the thermodynamic mechanism of absorption CO2 capture based on thermal driven mode and provides insight into the design of new absorbent.