Fundamentals and thermodynamics of gasification of carbonaceous materials were presented. Bituminous coals from 4 Polish coal mines were analyzed for chem. compn., carbonized at 600 degrees C in a pilot plant (40-70 kg/h) and gasified with air at 750-1000 degrees C in fluid bed reactor. The reaction of CO2 with C to CO and O (adsorbed on C surface) was analyzed from thermodynamic point of view to det. its stoichiometry and equil. consts.