The Effect of Hydrothermal Pre-Treatment of Coal, Biomass and Coal-Biomass Mixture on Fuel Properties

Abstract

Hydrothermal pretreatment was applied to wood sawdust, Trakya lignite and wood sawdust-Trakya lignite mixture (50%, wt) individually. Changes in fuel properties and thermochemical conversion characteristics of each were observed. In addition, the synergistic effect of biomass on coal with hydrothermal pretreatment of the mixture was investigated. After hydrothermal pretreatment, where the optimum conditions were 230 °C and 90 minutes, fixed carbon percentage and heating value increased and ash content decreased in all fuels. Compared to lignite and wood sawdust, a fuel with higher elemental carbon content, lower oxygen percentage and higher calorific value was obtained when the mixture was co-hydrothermally pretreated. Hydrothermal pretreatment applied to the mixture modified the structural properties and volatiles of the mixture. For this reason, the reactivity of the hydrothermal pretreated mixture in pyrolysis and combustion reactions increased, and the peak temperatures at which the mass loss rate was maximum were shifted to higher.