Inventory of the French densified log market: Characterization and emission factors measurement of twenty commercial briquettes

A panel of twenty commercial briquettes representative of the French market was set up with the different actors of the French densified log industry. The selected briquettes were characterized via the determination of their water and ash content, their ultimate and elemental composition and their heating value. Pollutant emission factors during the combustion of the briquettes were evaluated in real conditions in a domestic stove with natural draught. Gaseous pollutants like CO, CO2, NOx, SO2 and THC (Total HydroCarbons) were monitored. Particulate emissions in mass (TSP) and number (PM2.5) were also measured. Briquettes characterizations showed that the majority of the data determined in laboratory are in agreement with the one announced by the producers. Moreover several briquettes are in agreement with limitation established by the EN ISO 17225 standard. Combustion tests showed that the use of densified fuel instead of traditional log does not lead to a significant degradation of the environmental performances of the stove. Some briquettes present emission factors close to the one measured with traditional wood log. Several recommendations concerning briquettes characteristics were drawn from this study.