熔盐电解还原二氧化碳制碳技术

摘要

This paper investigated the production of fuel level carbon by electrolysis of molten carbonate mixture Li0.896Na0.625K0.479CO3 at high temperature and the regeneration of carbonate electrolyte by the intermediate products Li2O,Na2O,and K2O,with the absorption of CO2. The electrochemical properties of the reaction were analyzed by cyclic voltammetry and polarization curve. The effects of electrode material,reaction temperature,different current intensities and electrolytic time under same electric quantity in the reaction were also investigated. The surface morphology , composition and phase structure of the electrolysis products were characterized by SEM-EDS , TG/DTA,and XRD. The experimental results showed that the electrode potential decreased as temperature increased with a high electrode stability when Fe was used as cathode and Ni as anode. The preferable reaction temperature was 500 ℃. At the current intensity of 1.0 A and the electrolytic time of 1h,the current efficiency reached 65.98%and the obtained amorphous carbon was higher than 80%.%通过电解高温熔融Li0.896Na0.625K0.479CO3混合碳酸盐制取碳燃料，并由中间产物Li2O、Na2O、K2O吸收空气中CO2使碳酸盐电解质再生，从而构筑一个完美的良性循环，最终将CO2转化为C物质。实验通过极化曲线、循环伏安曲线对反应的电化学性能进行了研究，考察了电极材质、电解温度以及相同电量下不同电流强度和电解时间对反应结果的影响，并借助SEM-EDS、TG/DTA、XRD等手段对提纯后的产物进行表征。结果表明：Fe作阴极、Ni作阳极时的电势值较低、电极稳定性较好；随温度的升高，电势的绝对值降低，温度为500℃时对反应较有利；1 A·h的电量下，电流强度1.0 A、电解时间1 h时，反应的电流效率较高，可达65.98%；电解产物为无定形碳，含碳量可达80%以上。本研究为二氧化碳的资源化利用提供了一种新途径。