Influence of Cellulose and Lignin-Rich Biomass on Catalyst Performance: A Study with Walnut Shell and Corn Stover Gasification

This study investigates the gasification of cellulose, lignin, corn stover (rich in cellulose) and walnut shells (rich in lignin) using CaO as a catalyst. The objective was to understand the effect of the different biomass components on the gasification products and the performance of the CaO catalyst. Notable results indicate distinctive product distribution: cellulose yields higher liquid (58%) and CO (95.36%) products, while lignin produces increased H₂ (47.88%), CH₄ (34.34%), and CO₂ (29.58%). Gasification of biomass feedstocks, corn stover (cellulose-rich) and walnut shell (lignin-rich), aligns with pure cellulose and lignin trends. Catalyst characterization highlights that cellulose exhibits a greater tendency for coke formation, leading to elevated tar compounds and coke deposition on the catalyst surface. The solid residue from cellulose gasification displays a smaller pore volume (5.70 m²/g) and specific surface area, indicating undesirable catalyst rearrangement. XRD analysis indicates a higher carbonation rate of CaO in lignin-rich gasification, leading to increased CaCO₃ formation. Further results show a higher CO₂ concentration (3.35 mol/kg) and lower CO production (0.54 mol/kg) in corn stover gasification, contrasting with walnut shell (CO₂: 14.24 mol/kg, CO: 1.24 mol/kg). The study underscores the quantitative assessment of biomass composition for optimizing gasification processes, vital for catalyst selection and ensuring efficient CO₂ capture in industrial applications.