Hydrogen production in plasma gasification of pulp-derived organic waste: Numerical analysis using MHD-CFD...

The increasing demand for sustainable energy sources has led to significant research into biomass-derived hydrogen production. Among biomass sources, lignin, a byproduct of the pulp and paper industry, represents a promising renewable feedstock for hydrogen generation through gasification. However, conventional gasification techniques face challenges in achieving efficient decomposition due to the complex polymeric structure of lignin. In this study, a DC non-transferred thermal plasma process was employed to gasify pulp-derived organic waste (POW) under controlled conditions, optimizing the hydrogen yield while minimizing CO and CO₂ generation. Plasma jet characteristics were numerically analyzed using Magnetohydrodynamic (MHD) and Computational Fluid Dynamics (CFD) models to investigate temperature, velocity profiles, and residence time effects on lignin decomposition. The results demonstrated that an input power of 8 kW at a feeding rate of 0.250 g/min produced the highest hydrogen yield of 37.4%, attributed to enhanced molecular fragmentation under high-temperature and high-enthalpy conditions. Additionally, vector field analysis revealed that recirculating eddies in the reactor prolong lignin exposure to the high-temperature zone, further promoting decomposition. This study highlights the potential of thermal plasma technology as an efficient and environmentally friendly approach for waste-to-hydrogen production, offering a scalable solution for sustainable energy generation.