FORMATION OF DIOXINS AND OTHER SEMIVOLATILE ORGANIC-COMPOUNDS IN BIOMASS COMBUSTION

This paper identifies advantages of using biofuels and biomass mixed w ith coal in combustion. The availability of biomass with regard to lan duse is reviewed, followed by a brief account of the combustion proces s and the concomitant formation of semi-volatile organic compounds. Ch emical compositions of selected biofuels and coal are presented. Route s of formation for polychlorinated dibenzodioxins/furans (dioxins and furans) are illustrated with subsequent reference to associated emissi ons. Graphs in the paper show coal and biofuel propensities for formin g dioxin and furan isomers followed by methods for predicting emission levels and isomer distributions within combustion systems. The final sections of the paper summarise recent equilibrium concentration studi es and discuss the ongoing combustion experiments being conducted in t he University of Leeds' Department of Fuel and Energy. Preliminary res ults are presented and discussed, finishing with three main experiment ally-drawn conclusions. (C) 1998 Elsevier Science Ltd. All rights rese rved.