The influence of food waste on dioxin formation during incineration of refuse-derived fuels

We report a preliminary characterization of three refuse-derived fuels (RDFs) produced from recovered wood (RW) and two municipal solid wastes (MSWs) with different food waste contents. The fuels were characterized with respect to elemental composition and emissions of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) during combustion in a full-scale incinerator. The first RDF (RDF 1) had a low food waste content because it was based on MSW collected from a region where extensive separation of kitchen waste in the household is common. RDF 2 was based on MSW from a region with no organized separation of kitchen waste and therefore had a higher food waste content. A RW fuel with no added MSW was combusted to provide reference data.RDF 1 had very favourable fuel quality and PCDD/F emissions. In particular, its combustion generated lower PCDD/F concentrations (14.6 ng/m3) than that of RDF 2 (23.9 ng/m3) or RW (22.6 ng/m3). This may have been because its relatively high heating value increased its combustion efficiency and the relatively high Cl and Fe contents of RDF 2 promoted PCDD/F formation and chlorination. Both RDF materials had lower moisture contents and higher heating values than the RW fuel.