The present work deals with the biogas in a combustor with regard to its combustion features under differing conditions of H2O content and H2S. The content of water (H2O) vapour has been changed from 0% to 10% and a CFD code has been employed while implementing numerical investigations. In modelling, a combustion model (the PDF/Mixture Fraction) along with a turbulence model (the k-epsilon standard turbulence model) has been utilised. This study also deals with the combustion performances of the biogas by the addition of a different quantity of H2O into the biogas. The Emissions and the flame temperature of the biogas through the combustor apparently seem to be strikingly affected by the changes in H2O contents. It is interesting to note that the flame temperature zones change their positions and advance to the burner's downstream. The rise in flame temperatures of the biogas can be attributed to the change in H2O content caused by a better fuel-air mixture. It is also observed that adding H2O into the biogas lowers the axial temperature levels. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.