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

From the paper

Abstract

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.