Catalytic steam-gasification of olive pomace biowaste for enhanced hydrogen production

Olive pomace (OP), a major biowaste in Morocco, is discarded in a non-environmentally-friendly manner. Harnessing this potential as a bioenergy source fosters a circular economy. Among the various options for biomass utilization, gasification is the most viable pathway because of its environmental advantages. However, low hydrogen yields and high tar and CO₂ emissions are significant challenges in biomass gasification. This study used Aspen plus® commercial software to develop olive pomace catalytic steam gasification. The system was evaluated by varying the reaction temperature, steam-to-biomass ratio, equivalent ratio, and CaO-to-biomass ratio. The simulation results demonstrated that the synergetic effect of steam and the CaO catalyst likely catalyzes volatile cracking and CO₂ absorption, driving steam reforming and water gas shift reactions forward, thus increasing the H₂ yield. The economic results support the viability of OP gasification, with a 2.43-year payback period and a net profit of $257.88 per ton of OP.