Thermochemical transformation of CO2 for CH4 production using metal hydride and carbonates as portable sources

GRASSO, MARÍA LAURA; ROZAS AZCONA, SARA; ARNEODO LAROCHETTE, PIERRE; APARICIO, SANTIAGO; GENNARI, FABIANA

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2023

0360-3199

The thermochemical reaction between MgH2 and Li2CO3 is investigated for the first time for the CO2 transformation into fuels with and without nickel as a catalyst. Successful production of CH4 with high yields is reached depending on different reaction conditions such as microstructural refining, MgH2:Li2CO3 molar ratio, temperature and time. In absence of a catalyst, a methane yield of 68.2% was achieved by heating the milled MgH2:Li2CO3 mixture at 450 °C for 5 h. The global mechanism involves the reduction of CO2 from Li2CO3 by MgH2/Mg, producing CH4 and Li2O/MgO. For the Ni-catalyzed system, the highest methane yield of >90% was reached at 400 °C after 5 h of thermal treatment. The global process responds to a Sabatier reaction, with a contribution of a direct reduction of CO2 depending on the starting mol ratio. The results demonstrate that thermochemical activation of the Ni-catalyzed MgH2:Li2CO3 mixture is a powerful process for the generation of CH4 and CO2 utilization.