Process Simulation and Optimization of Green Hydrogen Production from Rubberwood Sawdust Pellets Via Gasification Using Unisim Design for Oil Refining

Abstrak

Indonesia pushes to expand renewable energy to create growing interest in low carbon hydrogen. Rubberwood processing generates large volumes of sawdust that are commonly pelletized for fuel, offering a locally available biomass feedstock for hydrogen rich gas production. This study evaluates the potential of producing green hydrogen from rubberwood sawdust pellets through gasification using process simulation. Feedstock properties were determined through proximate and ultimate analyses and implemented in a two stage simulation framework consisting of pyrolysis followed by gasification. The model was validated against published experimental data for steam gasification of wood residue, and the deviation between predicted and reference gas compositions was evaluated using the root mean square error. After validation, sensitivity analyses were conducted at a gasifier temperature of 700 °C for three gasifying agent configurations: steam only, steam with air, and steam with oxygen. Under steam-only operation, increasing S/B from 0 to 1.0 increased H₂ from approximately 44 to 56 mol%, while HEE increased from about 27 to 36% and LHV decreased from about 11.4 to 8.6 MJ/Nm³. Under steam plus air, increasing S+E/R to about 1.0 reduced H₂ from approximately 56 mol% to near zero while CO₂ increased from about 30 to 85 mol%. Under steam plus oxygen, increasing O/B to 1.0 reduced H₂ from approximately 56 to 22 mol% and increased CO₂ from about 30 to 73 mol%. Overall, the results indicate that steam rich and oxygen lean operation is the most favorable pathway for enhancing hydrogen rich gas production from rubberwood sawdust pellets and provide a simulation basis for selecting operating conditions to support national energy resilience.

Kata kunci

• hydrogen efficiency
• lower heating value
• cold gas efficiency
• refining
• sensitivity analysis