Chemical looping gasification of palm oil mill effluent for hydrogen production – An Aspen plus modeling

Hydrogen (H₂) is emerging as a clean energy source, and the production of clean hydrogen from waste biomass, particularly palm oil mill effluent (POME), holds significant promise for global greenhouse gas mitigation. The rapid proliferation of oil palm plantations across Latin America, Africa, and Asia, coupled with the substantial water requirements for crude palm oil extraction highlights the environmental challenges associated with palm oil production. This study investigates the integration of hydrothermal gasification (HTG) and syngas chemical looping (SCL) for the co-production of hydrogen and power from POME. A process model was developed in Aspen Plus to evaluate heat and mass balances, focusing on the influence of gasification temperature and POME moisture content on syngas yield and composition. Results indicate that higher temperatures and lower moisture content increase hydrogen concentration in syngas, though this also raises the gasifier's heat duty and affects overall energy efficiency. The hydrogen yield increased markedly from 36.74 to 129.38 kg per 1000 kg of dried POME as the temperature rose from 400 °C to 500 °C. The highest energy efficiency of 45.21 % was achieved at 400 °C with a POME moisture content of 65 wt%. This integrated system promises higher energy efficiency, leveraging excess energy from palm oil mills. By addressing both energy recovery and environmental sustainability, the proposed HTG-SCL integration represents a viable strategy for decentralized bio-hydrocarbon production, warranting further exploration of its technical and economic feasibility.