Decarbonizing cement production via tail-end integration of solid oxide electrolysis for CO2 reduction

Abstract

The calcination process in cement production plants (CPPs) accounts for over 60 % of carbon dioxide (CO2) emissions; therefore, carbon capture processes is essential for reducing greenhouse gases. Additionally, highpurity CO serves as a reactant in chemical industries and as an energy storage medium, due to its lower energy requirements for storage and transportation compared to hydrogen (H2), provided that it can be produced efficiently. The purpose of this study is to utilize CO2 captured from a CPP and integrate it with a solid oxide electrolysis cell (SOEC) system to produce carbon monoxide (CO). A numerical model is developed using Aspen Plus (R) to design an integrated carbon capture and conversion system composed of a CPP, calcium looping (CaL) process, SOEC, CO absorption separation process (COSORB), and Rankine Cycles (RCs). The developed model is validated by comparison with the experimental data. The LSGM-based electrolyte sheets are fabricated via tape casting and warm isostatic pressing, followed by the ultrasonic spray deposition of electrodes and a buffer layer. Electrochemical performance is evaluated under varying CO2/CO gas compositions (90/10, 70/30, and 50/50) and cathode flow rates (193.5, 129.0, and 96.7 sccm), using I-V curves and electrochemical impedance spectroscopy (EIS) analysis. Parametric analysis is conducted on the proposed system according to operating conditions of stack temperature, current density, the number of cells within the stack, and the molar fraction of CO The results show that total efficiency of the SOEC system and SOEC-RC system reach 92.2 % and 97.7 %, respectively, under the nominal condition of 850 degrees C, 1.0 A cm-2, 1,600,000 cells, and 30 mol% CO. This study proposes a novel approach for the reduction of CO2 emissions from industrial facilities.