Synthesis of Graphite and Hydrocarbons by Reaction between Calcite and Hydrogen

The reaction of calcite with hydrogen was investigated over a range of pressure, temperature, and time. The reaction initiates at about 500 degrees C. Its primarily temperature-dependent rateproceeds in a crystallographically anisotropic manner, and reaction products are CaO, Ca(OH)(2), H(2)O, CO, CH(4), C2H(6), and C (graphite), plus a black solid residue that may be hydrocarbon.