Reductive Calcination of Mineral Magnesite: Hydrogenation of Carbon Dioxide without Catalysts

Abstract The conversion of mineral magnesite to magnesium oxide, methane, carbon dioxide, and carbon monoxide in a hydrogen atmosphere at ambient pressure and overpressure without catalysts is discussed. Low temperature and elevated pressure facilitate CH 4 formation whereas moderate to high temperature and low pressure facilitate CO formation. Methane is formed directly without any additional catalyst. CO 2 emissions are decreased substantially in reductive calcination. Additional experiments revealed that reductively calcined magnesium oxide is a highly active reverse water‐gas shift catalyst. CO formation from gaseous CO 2 and H 2 at catalytically active magnesium oxide was reproducibly confirmed. Further reduction of carbon monoxide to methane is not catalyzed by reductively calcined magnesium oxide.