The structural evolution of the chars from pyrolysis of biomass components(cellulose, hemicellulose and lignin)in a xenon lamp radiation reactor was investigated. The elemental composition analysis showed that the C content increased at the expense of H and O contents during the chars formation. The values of ΔH/C/ΔO/Cfor the formation of cellulose and hemicellulose chars were close to 2, indicating that dehydration was the dominant reaction. Meanwhile, the value was more than 3 for lignin char formation, suggesting that the occurrence of demethoxylation was prevalent. FTIR and XRD analyses further disclosed that the cellulose pyrolysis needed to break down the stable crystal structure prior to the severe depolymerization. As for hemicellulose and lignin pyrolysis, the weak branches and linkages decomposed firstly, followed by the major decomposition. After the devolatilization at the main pyrolysis stage, the three components encountered a slow carbonization process to form condensed aromatic chars. The SEM results showed that the three components underwent different devolatilization behaviors, which induced various surface morphologies of the chars.
Haizhou LinShurong WangLi ZhangBin RuJinsong ZhouZhongyang Luo
Acetic acid was selected as the model compound representing the carboxylic acids present in bio-oil.This work focuses the co-cracking of acetic acid with ethanol for bio-gasoline production.The influences of reaction temperature and pressure on the conversion of reactants as well as the selectivity and composition of the crude gasoline phase were investigated.It was found that increasing reaction temperature benefited the conversion of reactants and pressurized cracking produced a higher crude gasoline yield.At 400°C and 1 MPa,the conversion of the reactants reached over 99%and the selectivity of the gasoline phase reached 42.79%(by mass).The gasoline phase shows outstanding quality,with a hydrocarbon content of 100%.
