Effect of individual organic components on thermal decomposition and generation of monocycle aromatic hydrocarbon in pyrolysis of cellulose/xylan/lignin mixtures

Individual organic components namely cellulose, xylan and lignin are fundamental and essential factors for generation of bio-based monocyclic aromatic hydrocarbons (MAHs) from pyrolysis of lignocellulosic biomass. In this study, the influence of individual components on the characteristics of thermal decomposition and MAHs generation in pyrolysis of cellulose/xylan/lignin mixtures were investigated by a TG-MS analyzer and a Py-GC/MS analyzer. Results show that both increase in contents of cellulose and xylan were conductive to the thermal decomposition of cellulose/xylan/lignin mixtures, while the increase in content of lignin presented the opposite effect. The orders of effect on the thermal decomposition were cellulose > xylan > lignin. Benzene was released in pyrolysis from 281 to 766°C, and its release amount increased with the increased cellulose, xylan, or lignin with various mechanisms. Toluene was released from 281 to 692°C and its release amount was only increased with the increased lignin. Compared to linear heating technique (15°C/min), fast pyrolysis technique (20°C/ms) was conductive to the formation of xylene. MAHs was rarely directly produced both in pyrolysis of cellulose and xylan, but both the presence of the two components were beneficial to promoting MAHs yield. The promotion ratio of the increased cellulose (86.13%) was higher than that of the increased xylan (30.73%).