Effects of wet torrefaction on pyrolysis of woody biomass fuels

摘要

The pyrolysis of Norway spruce and birch woods under nitrogen atmosphere was studied by means of a thermogravimetric analyzer operated in the non-isothermal mode, followed by a kinetic analysis employing a three-pseudo-component model with nth-order reactions. Raw woods and the woods treated via wet torrefaction in the conditions of various temperatures (175, 200, 225 degrees C) and holding times (10, 30, 60 min) were included in this work. The study showed that wet torrefaction resulted in higher pyrolysis peaks for the woods, but less mass of volatiles was released during pyrolysis. The effects of wet torrefaction on pyrolysis of the lignocellulosic components are different. The activation energy of hemicellulose was significantly reduced by wet torrefaction. However, those for cellulose and lignin were slightly increased by wet torrefaction.