Experimental and Aspen Plus Simulation of Rice Husk Pyrolysis with Integrated Steam Reforming for Hydrogen-Rich Syngas Production

Abstract This study experimentally investigated the slow pyrolysis of rice husk and complemented the experimental work with Aspen Plus simulations to evaluate syngas composition and hydrogen production potential. Experiments were conducted over a temperature range of 300–500 °C under both isothermal and non-isothermal conditions. The results indicated that isothermal pyrolysis (at 500 °C) produced the maximum liquid yield and non-condensable gases while reducing biochar formation. A model was established in Aspen Plus using RYield and RGibbs reactor blocks, and it was validated against experimental data at 500 °C, exhibiting strong agreement with relative errors below 10%. A steam reforming unit was incorporated using reactor equilibrium to enhance hydrogen production, where pyrolysis vapours were subjected to secondary reforming at elevated temperatures. A comprehensive parametric analysis revealed that a reforming temperature (700 °C) and a steam flow rate of 100 kg/h maximized hydrogen yield, achieving a mole fraction of 0.5562 with negligible methane content. The model effectively captured the effect of steam input and process temperature on gas composition, confirming consistency with trends reported in the literature. These findings demonstrated that integrating slow pyrolysis with steam reforming offers a viable pathway for generating hydrogen-rich syngas from rice husk. Moreover, the validated Aspen Plus model proved to be a valuable tool for process optimization, system design, and potential scale-up in sustainable bioenergy applications.