CO_(2)熔盐捕集与电解单质碳过程调节  

Regulation of CO_(2)molten salt capture and electrolysis to elemental carbon

作　　者：贾亚东 吴涛[1] 陈云飞 朱钊海潭 王明涌 JIA Yadong;WU Tao;CHEN Yunfei;ZHU Zhaohaitan;WANG Mingyong(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学绿色低碳钢铁冶金全国重点实验室,北京100083

出　　处：《工程科学学报》2024年第10期1776-1785,共10页Chinese Journal of Engineering

基　　金：中国宝武低碳冶金创新基金资助项目(BWLCF202210)。

摘　　要：CO_(2)熔盐捕集与电解制备单质碳材料由于具有良好的选择性,被认为是一种极有前景的碳捕集利用与封存(CCUS)技术.然而,目前关于CO_(2)在熔盐体系下的动力学捕集机理研究尚显不足,并且电解过程中电耗较高,生产成本偏大,因此CO_(2)高效捕集与低电耗电解是关键.本文计算了CO_(2)熔盐捕集转换碳酸盐热力学和碳酸盐电解理论电压与电耗,通过在线气体质谱仪、碳硫分析仪等研究了典型CaCl_(2)基熔盐中CO_(2)捕集动力学规律.通过恒电压电解、扫描电子显微镜(SEM)、拉曼光谱(Raman)等,在典型三元Na_(2)CO_(3)–K_(2)CO_(3)–Li_(2)CO_(3)熔盐和三元CaCl_(2)–NaCl–CaO熔盐中考察了温度和电压对CO_(2)电解制备单质碳材料电解过程、电耗和产物结构的影响规律.结果表明,相比于碱金属氧化物,CaO是较佳的CO_(2)捕集剂,捕集转化获得的CaCO_(3)具有最低的理论分解电压和电耗;在典型CaCl_(2)–3.0%CaO(质量分数)熔盐中,CO_(2)的捕集容量为0.016 gCO_(2)·g^(−1);相比于Na_(2)CO_(3)–K_(2)CO_(3)–Li_(2)CO_(3)熔盐,CaCl_(2)–NaCl–CaO熔盐捕集CO_(2)具有更低的电解电压和电耗,750℃和1.5 V最佳条件下,电解单质碳材料电流效率达到95.3%,电解电耗最低仅为14.1 kW·h·kg^(−1).本研究不仅为寻找性能优异、价格低廉、环境友好的CO_(2)熔盐捕集材料提供了基础,也为实际电解优化工艺指标提供理论依据.High-temperature molten salt capture and electrolysis technology of CO_(2)for the effective preparation of elemental carbon materials are considered to be an exceedinglyare gaining traction as promising carbon capture utilization and storage technology.The reason is their excellent selectivity and ease of operation,making them suitable for the effective preparation of elemental carbon materials from CO_(2).Nonetheless,the current research on the kinetic mechanism of CO_(2)capture in high-temperature molten salt systems is inadequate.Furthermore,the energy consumption and production costs associated with the process of preparing elemental carbon materials through CO_(2)molten salt electrolysis are relatively high.Therefore,achieving efficient CO_(2)capture in high-temperature molten salts and low-energy consumption electrolysis is very crucial.This paper delves into the thermodynamics of CO_(2)capture by various alkali metals/alkaline earth metal oxides.It also compares the theoretical decomposition voltage and energy consumption of various alkali metals/alkaline earth metal carbonates.The capture behavior of CO_(2)in typical binary chloride molten salts is also examined.The study further explores the thermodynamics of CO_(2)capture in molten salts to carbonates and calculates the theoretical voltage and power consumption during carbonate electrolysis in a high-temperature molten salt system.The kinetics of CO_(2)capture in typical CaCl_(2)-based molten salts are examined by advanced technologies such as online gas mass spectrometry,carbon–sulfur analyzer,X-ray diffraction,and energy spectroscopy.The effects of temperature and voltage on the electrolysis process,electrolytic energy consumption,and product structure of elemental carbon materials prepared by CO_(2)electrolysis are investigated in typical ternary Na_(2)CO_(3)–K_(2)CO_(3)–Li_(2)CO_(3)molten salts and ternary CaCl_(2)–NaCl–CaO molten salts using scanning electron microscopy(SEM),Raman spectroscopy,and constant voltage electrolysis.The results

关 键 词：二氧化碳捕集 电解 高温熔盐 单质碳 电耗 

分 类 号：TQ127.11[化学工程—无机化工]