The process of steam co-gasification of hard coal and biomass is regarded as environment friendly alternative to classical fossil fuel combustion, especially in the light of continuous increase in energy demand and recognition of environmental concerns related to fossil fuel processing. In the paper, the results of experimental comparative study of steam gasification and co-gasification of hard coal and energy crop (Andropogon gerardii) biomass in a laboratory-scale fixed bed reactor at the temperatures of 700, 800, and 900°C are presented. The gas chromatography technique was used in analyses of concentrations of the main product gas components, that is, hydrogen, carbon monoxide, carbon dioxide, and methane. Some regularities in terms of variations between gasification and co-gasification product gas composition were observed, e.g., carbon monoxide content in biomass gasification and co-gasification product gas was on average approximately half the amount observed in hard coal gasification. Application of Fe2O3 and CaO in co-gasification led to increase in hydrogen content with simultaneous CO2 capture. Chemisorption of CO2 with CaO in the process of steam co-gasification was effective at 700°C and 800°C and resulted in average hydrogen content increase from 61 to 87%vol and from 62 to 76%vol at 700°C and 800°C, respectively, when compared to co-gasification without Fe2O3 and CaO.