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

Abstract

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.