Renewable phenols and fuel production from catalytic pyrolysis of lignin using microwave irradiation heating

摘要

The aim of this study is to explore catalytic microwave pyrolysis of lignin for renewable phenols and fuels due to the abundant availability and characteristics of the chemical structure of lignin. A central composite experimental design (CCD) was used to optimize the reaction condition of this process. The effects of reaction temperature and ratio of catalyst to lignin on product yields were investigated. GC/MS analysis showed that the main chemical compounds of bio-oils were phenols, guaiacols, hydrocarbons and esters, most of which ranged from 71-87% of the bio-oils depending on different reaction conditions. Bio-oils with high concentrations of phenol (45% in the bio-oil) were obtained. The calorific value analysis revealed that the high heatingvalues (HHV) of the lignin-derived biochars were from 20.4-24.5MJ/kg, about 3-24% increase compared to HHV of raw lignin. The thermal decomposition behaviors of lignin pyrolysis were studied by thermogravimetric analysis (TGA), and the kinetic parameters were investigated using thermogrametric analysis (TGA) data. The reaction mechanism of this process was analyzed.