CO₂ reutilization for methane production via a catalytic process promoted by hydrides

Abstract

CO2 is recycled to produce CH4 selectively by using complex hydrides as the hydrogen source and catalytic metal particles.

Catalysis effect on CO2 methanation using MgH2 as a portable hydrogen medium

“…29,30 More recent studies showed that CO 2 can be reduced on the surface of hydrides that act as catalysts, by means of the Sabatier reaction allowing the conversion of CO 2 to methane and closing the cycle of carbon. [31][32][33][34][35][36][37] This allows the use of H 2 stored safely in a solid matrix (MHx, M: metal, H: hydrogen), which could acts as a catalyst for the transformation of CO 2 into a gaseous fuel. In particular, it was found that some complex hydrides such as, for example, Mg 2 NiH 4 , Mg(BH 4 ) 2 , and LiAlH 4 possess good catalytic properties for the hydrogenation of CO 2 , generating different chemical compounds of industrial interest.…”

“…In particular, it was found that some complex hydrides such as, for example, Mg 2 NiH 4 , Mg(BH 4 ) 2 , and LiAlH 4 possess good catalytic properties for the hydrogenation of CO 2 , generating different chemical compounds of industrial interest. [31][32][33][34][35] Although the decomposition of alanates in atmospheres with CO 2 has been little explored, it is known that at temperatures greater than 120°C, LiAlH 4 reacts with CO 2 , producing CH 4 , H 2 and metal oxides.…”

“…It was revealed that the reversed water-gas shift reaction (WGSR) followed by the methanation of CO in the presence of steam dominates the process for the Mg 2 FeH 6 -CO 2 system, whereas for the Mg 2 NiH 4 -CO 2 system, the CO 2 direct reduction has a strong contribution. 34 Interestingly, it was proved that the synthesis method of Ni metal complex hydride has an impact on the global mechanism. Under the same experimental conditions, the methanation via as-milled Mg 2 NiH 4 was proved to be faster and different from the one via as-sintered Mg 2 NiH 4 , with the presence of graphite in the solid phase.…”

“…Under the same experimental conditions, the methanation via as-milled Mg 2 NiH 4 was proved to be faster and different from the one via as-sintered Mg 2 NiH 4 , with the presence of graphite in the solid phase. 35 In addition, recently, the thermochemical CO 2 reduction by alkali metal hydrides (LiH and NaH) 34 or alkaline-earth metal hydrides (CaH 2 and MgH 2 ) 35 in the absence of catalyst was presented. Both investigations agree that the yield of methane obtained depends strongly on the type of hydride, the H 2 :CO 2 molar ratio and reaction conditions (temperature and time).…”

“…Owing to the fact that our investigation group have previously explored the methane production via a catalytic process promoted by hydrides containing iron and nickel 34,35 , in this work the use of cobalt was considered as this transition metal was also proved to have an excellent catalytic activity. 16,17,38 In particular, the feasibility of the use of MgH 2 for CO 2 conversion to CH 4 , analyzing the role of cobalt as catalyst was investigated deeply and the reaction conditions that favor the desired products were explored.…”