Hydrothermal gasification of sisal wastes as an alternative to conventional gasification for hydrogen-rich gas production

Gasification of biomass is widely recognized as a practical method of enhancing sustainable generation of hydrogen. This research investigates the optimal gasification pathway for higher hydrogen gas yields in syngas produced from sisal wastes. Comparative studies on steam gasification (SG) and hydrothermal gasification (HTG) are modeled using Aspen Plus software. Key operating parameters including, temperature, pressure, and gasifying agent, are systematically analyzed for the two gasification methods. Optimization studies are further performed using Response Surface Methodology (RSM) in Design Expert software to determine the ideal operational conditions for each process. Results demonstrate that temperature exhibits positive effects on the hydrogen yield in HTG compared to SG. For both processes, increasing the gasifying agent enhances hydrogen yields. Optimization findings reveal that HTG outperforms SG in hydrogen production, although with a lower CGE to that of SG. The optimization results revealed high desirability values of 0.949 and 0.957 for the optimized conditions of HTG and SG, respectively. This study underscores the significance of process-specific parameter optimization and highlights HTG as a superior technology for converting sisal waste into hydrogen-rich syngas, offering enhanced efficiency and greater adaptability to the feedstock’s inherent characteristics. These insights provide a robust framework for advancing sustainable biomass gasification technologies.