Study on pyrolysis characteristics of red pepper stalks to analyze the changes of pyrolytic behaviors from xylophyta to herbage

To explore the changes of pyrolysis behaviors from xylophyta to herbage, pyrolysis properties of red pepper stalks (RPS) as a representative kind of biomass of high lignin content of agricultural residues were studied by using TGA and Py-GC/MS. The results indicated that contents of cellulose, 43.2 wt.%, and of lignin, 24.7 wt.% were higher than those of corn stalks, wheat stalks and cotton stalks, but closer to those of the poplar wood. The pyrolysis process mainly occurred in three stages, and with an increasing heating rate from 10 degrees C/min to 30 degrees C/min, the TGA curves shifted to a lower temperature. With an increase in pyrolysis temperature, the contents of sugars, phenols and furans decreased from 3.96%, 13.54% and 10.13% to 1.09%, 7.13% and 1.65%, respectively. The contents of hydroxyacetaldehyde and acetone reached a maximum 13.71% and 20.05% at 500 degrees C. At 300 degrees C levoglucose, pentanal and methyl furan content reached maxima of 3.63%, 13.09% and 7.49%, respectively. Different chemical components could account for the changes of pyrolytic behaviors from xylophyta to herbage. (C) 2016 Elsevier B.V. All rights reserved.