变湿吸附三维循环构建及能效分析

Construction of Three-Dimensional Moisture Swing Adsorption Cycle and Energy Efficiency Analysis

变湿吸附法以水为杠杆来高效驱动直接空气碳捕集,目前其循环理论及能效研究相对匮乏。本文从热力学循环的角度对变湿吸附工艺进行分析,在温度–湿度–吸附量三维坐标系中构建出六步变湿吸附循环。比较了基础恒温变湿吸附循环以及六步变湿吸附循环的理想比能耗、热力学效率及吸附剂效率等循环评价指标,并分析了温湿度对各评价指标的影响规律。在25℃、30%RH的吸附条件下,引入变温过程可至多降低28%的捕集能耗,并将热力学效率上限提高119%。

Moisture swing adsorption(MSA)method uses water as a lever to efficiently drive direct air carbon capture.At present,its cycle theory and energy efficiency research are relatively scarce.In this paper,MSA process is analyzed from the perspective of thermodynamic cycle,and a 6-step MSA cycle is constructed in the three-dimensional coordinate system of temperature,humidity,and adsorption capacity.Ideal specific energy consumption,thermodynamic efficiency and adsorbent efficiency of basic isothermal MSA cycle and the 6-step MSA cycle are compared,and the effects of temperature and humidity on each indicator are analyzed.Under the adsorption condition of 25°C and 30%RH,the introduction of temperature swing process can reduce capture energy consumption by 28%at most,and increase the limit of thermodynamic efficiency by 119%.