ASPEN Plus simulation of palm kernel shells, waste shiitake substrate, and sewage sludge co-gasification

An ASPEN Plus model, incorporating a kinetic model that includes tar cracking, was developed to simulate the co-gasification of palm kernel shells (PKS), waste shiitake substrates, and sewage sludge (SS). Different treatment methods were applied during the pyrolysis stage for various feedstocks. A comprehensive parameter analysis was conducted and the parameters included gasification temperature, feedstock blending ratio (BR), gasifying agent mixing ratio (MR), and equivalence ratio (ER). In PKS and SS co-gasification, BR and ER had the most significant impact on CO production, while MR and BR were key for H2 and CH4 yields. SS gasification performed optimally at low ER (0.1), while PKS preferred ER 0.3. The highest H2 yield was 0.0032 kg/h, CO 0.1171 kg/h, and the optimal H2/CO ratio of 0.89 occurred at 800 °C, SS feed, pure steam, and ER 0.4. In shiitake substrate and SS co-gasification, BR influenced syngas components, with higher ratios reducing CO, H2, and CH4 yields. The optimal ER for CH4 and CO production was 0.2, and the highest H2/CO ratio (2.47) occurred at 900 °C, pure SS, 60 % steam/40 % CO2, and ER 0.4. Shiitake gasification produced the highest CO and H2, while SS had the highest H2/CO ratio.