Partially Oxidative Torrefaction of Woody Biomass Pellets: Burning Behaviour and Emission Analysis

Abstract Non-conventional torrefaction under partially oxidative conditions is an emerging cost-effective thermochemical pre-treatment method to improve the quality of biomass for energy applications. The literature lacks data on combustion torrefied oxygen-deficient atmosphere with actual reactor (inevitable non-uniformities in thermal environment). In this work, a dual mode fixed-bed (torrefaction) and combustor was operated Australian pellets, torrefy fuels at 275 °C 30 min using (O 2 : 5 vol%, balance N ) then combust them. Combustion behaviour particular focus gaseous emissions raw, blended (25% torrefied), (100%) pellet batch-type investigated. decomposition analysed thermogravimetric analyser understand impact constituents direct tested samples. Results indicate that unlike raw biomass, burned 45% faster, attained high packed-bed temperatures (1382 °C) exhaust gas (657 latter (bed: 1128 °C, exhaust: 574 similar airflow. Additionally, 100% pellets emitted 38% less NOx compared pellets. However, low CO values were higher primary airflows raw. dominated by both flaming smouldering phases modified efficiency (MCE) value 91%, whereas occurred phase MCE 98% same airflow (0.35 kg·m −2 ·s −1 ). outcomes work provide useful insights into viability alongside other industrial processes generating (waste) heat flue gases.