Comparative studies on thermochemical behavior and kinetics of lignocellulosic biomass residues using TG-FTIR and Py-GC/MS

Abstract

In the present study, similarities and variances in thermochemical behavior and composition of degradation products among cellulose, lignin, and agricultural residues (sawdust, black tea, barley, bagasse, rice husk, and corncob) were assessed using TG analysis, DSC, TG-FTIR, and Py-GC/MS. The experimental results indicated the temperature range of maximum mass loss between 295–430 °C for cellulose, 155–600 °C for lignin, and 150–500 °C for agricultural residues representing the feedstock's active pyrolysis region. The FTIR analysis established the presence of CO, CC, CO2, CO, CO, and CH4 gaseous functional groups with a strong synergistic effect. The CO2 was the primary product in gaseous mixtures, and their yield enhanced at elevated temperature. The characteristically dependent pyrolysis product groups were anhydro-sugars (84.9%–90.1%) and furans (4.1%–5.6%) in cellulose; phenols (69.6%–77.4%) and aldehydes (5.9%–7.9%) in lignin; furans (1.4%–47.7%) and acids (15.8%–37.3%) in agricultural residues, respectively. Bagasse and corncob trailed similar thermal behavior with furans (30.8%–47.7%) as major pyrolysis products, whereas acids (83.1%–88.7%) were prevalent in rice husk. The mean values of apparent activation energy evaluated by the isoconversional Friedman method were 174.8, 123.1, 160.7–217.3 kJ mol−1, respectively, for cellulose, lignin, and agricultural residues. The results presented comprehensive data in elucidating the influence of individual biomass components at optimized temperatures for higher selectivity of value-added chemicals and bioenergy.