A novel integrated CO2 capture and direct methanation process using Ni/CaO catal-sorbents

Abstract

A novel integrated CO₂ capture and utilization (CCU) process for direct methanation was proposed to reduce the total required thermal energy by effectively combining CO₂ capture and conversion using a Ni/CaO catal-sorbent. Compared to the conventional carbonation/decarbonation process, carbonated Ni/CaO catal-sorbents were regenerated by converting captured CO₂ to CH₄ under a H₂ atmosphere at temperatures lower than those required for CO₂ desorption. According to the theoretical and experimental results, the optimum reaction temperature for the novel CCU process was determined at 500 °C; while the Ni/CaO catal-sorbent exhibited high CO₂ capture and direct methanation capacity without sintering during consecutive cycle tests at 500 °C. Therefore, this new integrated CCU process for direct methanation could be a cost- and energy-effective approach to CH₄ production and climate emergency mitigation.