Influence of torrefaction temperature on the chemical composition of <i>Leucaena leucocephala</i> grown in Nigeria

Abstract

Wood is polymeric with varying quantities of extractives and inorganics. The quantity of the polymeric substances ( Cellulose, Hemicellulose and Lignin) can be changed by torrefaction. Hence, this study investigated the influence of torrefaction on the chemical composition of Leucaena leucocephala within the temperature range of 225 to 300°C. The compositional analysis of the lignocellulosic biomass involved the utilisation of both wet chemistry and gravimetric methods. These methods determined the quantities of hemicellulose, cellulose, Klason lignin, extractives, and ash content. The findings revealed notable variations in extractive, hemicellulose, and cellulose content across different temperatures and parts of the biomass. The hemicellulose content of Leucaena ranged from 24% to 33%. There was no significant difference in the ash content, although an increase in value from 1.57 at 225°C to 2.71 at 300°C was observed. Furthermore, the cellulose content decreased with rising temperature, whereas the lignin content increased. These results provide insights into the chemical transformations occurring in wood during torrefaction.