Reforming of natural gas and carbon dioxide into H-2 and CO is an efficient method to convert heat into chemical energy, thus offering interesting perspectives for capturing solar energy. The CHEMKIN and SENKIN codes have been applied to a model of the system C/H/O represented by 47 species and 215 reactions. Equilibrium states have been calculated as a function of temperature and pressure. It has been found that at pressures higher than 10 bar conversion efficiency is reduced considerably. Non-catalytic conversion kinetics have been derived for 5 bar pressure and temperatures from 800 to 1200 degrees C, clearly demonstrating the necessity of a catalytic converter.