In order to utilize low-grade coals, which contain high concentrations of sulfur (2-6 wt. %) and ash (>15 wt. %, dry basis), controlling pollutant emissions during combustion in domestic stoves and small-capacity industrial boilers, a composite solid fuel “coal-biomass briquette” with sulfur fixation function was produced in a pilot plant in Chongqing city, China. It was composed of 80 wt. % of low-grade coal and 20 wt. % of biomass (
e. g., wood chips and agricultural wastes) with a small fraction of sulfur-fixation additives. In this study, we investigated the ignition and combustion characteristics of the coal-biomass briquettes, and developed a new sulfur fixation additive made from sub-product in gas welding industries. It was found that the coal-biomass briquette has the lower ignition temperature and higher combustion efficiency than the usual coal briquettes, and that the newly developed additive was superior to limestone or scallop shells in sulfur fixation capability. This method is simple, economical, and efficient, in terms of emission control of SO
2, CO and other particulate pollutants from the combustion of low-grade coals using the conventional domestic stoves and boilers without modification. The coal-biomass briquette can be applicable for pollution control of coal combustion in some developing countries.
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