Hydrothermal Gasification of Biogas Digestate: a Parametric Study Using a Matlab-based Code

In this work, effect of process parameters on hydrothermal gasification (HTG) of biogas digestate are thermodynamically investigated using a Matlab-based code, which is capable of modelling the effects of the feedstock’s inorganic contents and elements. The effects of temperature (400-600 oC), pressure (250-300 bar), and feed concentration (10-40 wt%) towards the producer gas yield and composition are evaluated while considering the influence of inorganic components in the feedstock. The result shows that temperature and feed concentration play significant roles in determining producer gas composition and yield, whereas pressure only has little influence. Hydrogen production is favored by higher temperature, lower pressure, and lower feed concentration. It was also observed that the presence of inorganic components in the feedstock reduces the production of CO2, while H2 and CH4 is increased. The result of this study is essential in the future development of biogas digestate HTG.