Comprehensive investigation of the CO2 gasification process of biomass wastes using TG-MS and lab-scale experimental research

Wood, agriculture and food industry wastes are good feedstocks for thermal conversion via gasification to syngas production. Thus, gasification under CO2 atmosphere was proposed in this study. The following materials were selected as feedstocks: brewery spent grain, wheat straw, pine and hay. Preliminary studies of CO2 gasification were conducted using thermogravimetric analysis (TGA) with gas analysis (quadrupole mass spectrometer – QMS) in a temperature range from an ambient temperature up to 1100 °C. This allowed us to establish the main gasification stages and detect H2, CO, CH4 and C2H2. The main experiments of the gasification process were performed in a vertical fixed bed reactor under a pure CO2 atmosphere at temperatures of 800, 900 and 1000 °C. Solid and gaseous products were analysed. The investigation of char properties indicate enhancement of energetic properties. Analysing the obtained syngas composition found that 900 °C is the most sufficient process temperature to produce H2-rich syngas with the optimal level of biomass conversion for all studied samples.