Pyrolysis of agricultural waste biomass towards production of gas fuel and high-quality char. Experimental and numerical investigations

Abstract

Biomass wastes are sustainable, renewable, and promising energy sources. In this study, the pyrolysis of agricultural biomass was investigated to determine the most promising process parameters for pyrolytic gas production. The pyrolysis investigations were carried out under nitrogen atmosphere at 300, 400, 500, and 600 °C on the microscale using simultaneous thermal analysis and a laboratory-scale semi-batch vertical reactor. The solid, liquid, and gaseous products were characterised in detail, including the elemental and chemical composition. The gas and liquid products analyses were provided. It was found that the quality of the pyrolytic gas increased with temperature, both in terms of the pyrolytic gas yield and concentration of gaseous components (hydrogen and methane), whereas the carbon dioxide concentration decreased with temperature. The condensed vapours were rich in phenolic and aromatic compounds, and it was noted that the acetic acid concentration increased with temperature. The chemical functional groups in the char were determined using infrared spectroscopy. The carbon content increased with temperature, whereas the hydrogen content decreased. Further decomposition of the organic matrix was observed with increasing temperature. Additionally, chemical modelling of pyrolytic gas was performed using Ansys Chemkin-Pro software and compared with the experimental results. The computational results showed a good correlation with the measured pyrolytic gas composition, especially in the case of the major gas components.