Biocoal Briquettes Combusted in a Household Cooking Stove: Improved Thermal Efficiencies and Reduced Pollutant Emissions

摘要

Clean fuels are urgently needed to reduce household cooking emissions. The themial effiaencies (η_(th)) and pollutant emission factors (EFs) of biocoal briquettes (made from a mixture of biomass and coal powder) burned in a typical cooking stove were investigated and compared with those of coal briquettes and biomass briquettes. Biocoal briquette samples were obtained by molding blends of anthracite with 10-30 wt % crop straw of various types (maize straw, wheat straw, or rice straw). The optimum proportions for energy savings and PM_(2.5) EF reduction were found to be 15-20 wt %. Compared with the η_(th) of coal briquettes and biomass briquettes, the η_(th) of biocoal briquettes increased by 81-127% and 88- 179%, respectively, with the optimum addition ratios of crop straw, thile the delivered energy-based PM_(2.5) EFs of the biocoal briquettes were reduced by 61-67% and 99.0-99.5%, respectively. Delivered energy-based EFs of NO_x, SO_2, and toxic elements (As, Se, and Pb) also showed a significant reduction. These results indicated that biocoal briquettes can serve as a promising substitute for domestic solid fuel to reduce pollutant emissions and save energy.