Hydrogenation of CaCO3 for Methane by a Liquid Organic Hydrogen Carrier in the Presence of the Catalyst Precursor NiCO3

Conversion of calcium carbonate (CaCO3) to calcium oxide and methane (CH4) by renewable hydrogen is promising to retrofit the current CaCO3 decomposition processes in many industries and, at the same time, to replace their carbon dioxide emission by CH4 generation. This work studies CaCO3 hydrogenation by a liquid organic hydrogen carrier, 9,10-dihydrophenanthrene (DHP), and the catalytic effect of nickel carbonate (NiCO3) at 400 °C. It is found that NiCO3 in situ forms Ni particles of 200–900 nm in size that promote CH4 formation from CaCO3. At the NiCO3:CaCO3:DHP molar ratios of 1:10:55 and 400 °C, the total CO32– conversion, CH4 selectivity, and CH4 formation from CaCO3 are 89.5, 40, and 80.3%, respectively, in 40 min.