Biogas and syngas generated from biomass wastes are known as sustainable supplements for conventional fossil fuels. In this work, three typical types of biomass wastes were selected to go through anaerobic digestion followed by gasification process to generate biogas and syngas. For anaerobic digestion, standard BMP (Biomethane potential) test has been conducted to get the BMP value and biogas composition for each biomass waste. Subsequently, prediction of syngas produced from gasification has been done using a 1-D kinetic model validated by experimental data. Finally, gas mixture with different compositions have been studied in a multi-dimensional CFD IC (Internal Combustion) engine model based on KIVA4 and CHEMKIN. The indicated thermal efficiency and combustion performance have been investigated under different ignition timings and biogas compositions. The effects of ignition timings and biogas compositions have been analysed from both energetic performance, i.e. indicated thermal efficiency, and environmental performance, i.e. NOx emission.