Effects of microwave pretreatment on catalytic fast pyrolysis of pine sawdust

In this work, thermal behavior and pyrolysis products of pine sawdust after treated by different microwave pretreatment condition had been studied. Surface structure of samples getting collapsed after microwave pretreatment and the characteristics of thermal decomposition with CaO addition under four kinds heating rates was investigated by thermogravimetric analyzer. Pyrolysis process was carried and the products composition were detected both on Pyrolysis-Gas Chromatography/Mass Spectrometry. Under the condition of 567 W power treatments for 3 min, the yield of phenols rose from 3.64% to 18.21% and the ketones decreased from 55.80% to 40.27%. The activation energy was calculated by Flynn-Wall-Ozawa method. After microwave pretreatment, the activation energy of pine sawdust reach the maximum increase 7.26% at 329 W for 3 min, which meant that microwave pretreatment had lithe positive effect on promoting the pyrolysis reaction.