In-Depth Energy and Irreversibility Analysis in the Solar Driven Two-Step Thermochemical Water Splitting Cycle for Hydrogen Production  

作　　者：JIAO Fan LU Buchu CHEN Chen DAI Fei LIU Taixiu LIU Qibin 

机构地区：[1]School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China [2]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [3]School of Engineering and Science,University of Chinese Academy of Sciences,Beijing 100049,China [4]School of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310032,China

出　　处：《Journal of Thermal Science》2023年第1期1-16,共16页热科学学报（英文版）

基　　金：the financial support provided by the National Natural Science Foundation of China(No.52090061);the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.51888103)。

摘　　要：Hydrogen production via a two-step thermochemical cycle based on solar energy has attracted increasing attention.However,the severe irreversible loss causes the low efficiency.To make sense of the irreversibility,an in-depth thermodynamic model for the solar driven two-step thermochemical cycles is proposed.Different from previous literatures solely focusing on the energy loss and irreversibility of devices,this work decouples a complex energy conversion process in three sub-processes,i.e.,reaction,heat transfer and re-radiation,acquiring the cause of irreversible loss.The results from the case study indicate that the main irreversibility caused by inert sweeping gas for decreasing the reduction reaction temperature dominates the cycle efficiency.Decreasing reduction reaction temperature without severe energy penalty of inert sweeping gas is important to reducing this irreversible loss.A favorable performance is achieved by decreasing re-oxidation rate,increasing hydrolysis conversion rate and achieving a thermochemical cycle with a lower equilibrium temperature of reduction reaction at atmosphere pressure.The research clarifies the essence of process irrrversibility in solar thermichemical cycles,and the findings point out the potential to develop efficient solar driven two-step thermochemical cycles for hydrogen production.

关 键 词：thermochemical cycle hydrogen IRREVERSIBILITY THERMODYNAMICS 

分 类 号：TQ116.2[化学工程—无机化工]