The Impact of Fuel Properties on the Composition of Soot Produced by the Combustion of Residential Solid Fuels in a Domestic Stove

Soot is formed from the incomplete combustion of biomass and conventional fossil fuels. It consists largely of a carbonaceous core termed Elemental Carbon (EC) with adsorbed volatile organic species, commonly termed Organic Carbon (OC). Estimation of the ratio of BC/OC is critical as climate models have recognised the Global Warming Potential (GWP) of BC as the second most important climate forcing agent after carbon dioxide. This paper presents values of EC, OC and EC/TC (where TC = EC + OC) for three different soot types: Firstly, soots collected on filters from the combustion of eight fossil fuel and biomass residential solid fuels (RSF), burned in a 6 kW heating stove. Secondly, chimney soot deposits taken from 'real-life' stoves installed in domestic homes; and finally wick burner soots generated from biomass model compounds; namely eugenol, furfural and anisole. Values of the EC/TC ratios for wood logs, torrefied briquettes, coal and smokeless fuel are given. These ratios are highly dependent on burning conditions; namely the flaming and smouldering phases. The results of this study suggest that EC and OC emissions from various solid fuels differ substantially in composition and relative proportion, which is useful information for climate models.