Microwave pretreatment power and duration time effects on the catalytic pyrolysis behaviors and kinetics of water hyacinth

Abstract

In this work, the power and duration time of microwave pretreatment effects on water hyacinth were the main research objects. Surface structure of water hyacinth was broke by microwave radiation through Scanning Electron Microscope observation and the characteristics of thermal decomposition of water hyacinth with the catalyst under four heating rates was investigated by using the thermogravimetric analyzer. Calcium oxide was chosen to be the additive of the water hyacinth pyrolysis reaction. Pyrolysis product compositions were figured out by Pyrolysis-Gas Chromatography/Mass Spectrometry. The results showed that microwave changed the product composition effectively. Under optimal conditions, acids yield of water hyacinth decreased from 7.89% to 4.89% and the yield of sugars increased from 2.73% to 9.04%. Kinetic parameters were calculated by Flynn-Wall-Ozawa method. Under microwave pretreatment at 329 W and 567 W, the activation energy of water hyacinth first decreased and then rose with duration time increasing.