Characterization of primary thermal degradation features of lignocellulosic biomass after removal of inorganic metals by diverse solvents

Poplar wood powders were treated with distilled water, tap water, HCl and HF, respectively, to remove inorganics from the biomass and to investigate effect of demineralization processes on pyrolysis behavior of the biomass. TG and DIG revealed that maximum degradation temperatures rose slightly from 362 degrees C for control to 372 degrees C, 366 degrees C and 368 degrees C after demineralization with distilled water, HCl and HF, respectively. Maximum degradation rates also increased from 0.96%/degrees C for control to 1.15%/degrees C for HF-biomass, 1.23%/degrees C for DI-H2O-biomass, and 1.55%/degrees C for HCl-biomass. Analytical pyrolysis-GC/MS of demineralized biomasses produced approximately 45 pyrolysis compounds. Total amount of low molecular weight compounds, such as acetic acid, acetol, and 3-hydroxypropanal, was significantly lowered in the demineralized biomasses. But levoglucosan increased 2-10-folds in the demineralized biomasses. One of the features regarding lignin derivatives was the reduction of the amount of C6-type phenols, such as phenol, guaiacol, and syringol after demineralization. (C) 2010 Elsevier Ltd. All rights reserved.