Development and performance evaluation of a clean-burning stove

• A clean coal technology burning coal briquette in a clean-burning stove is reported.
• Thermal efficiency of the stove was raised to 68% compared with conventional stove.
• The clean briquette is excellent in SO2 control when burning in the new stove.
• Compared with conventional stove, reduction of indoor CO of new stove was verified.

Many suburb and rural households in the world are still using small coal-fired stoves for cooking and heating, which traditionally has been associated with low-efficiency combustion devices and low-grade coal, and the consequent severe air pollution. Therefore, it is very urgent to develop and widely disseminate clean and efficient combustion technologies for household use. This paper reported the development and research of a novel clean coal technology which burns clean coal-biomass briquette in a novel clean-burning coal stove. In order to reduce the emission of nitrogen oxides and particulate matters, this stove is designed with a pyrolysis chamber and a combustion chamber. In order to improve the thermal efficiency, the secondary air ducks are arranged to recover the waste heat in the ash pit and use it to warm up the inlet secondary air; sulfur retention agent calcium oxide & magnesium oxide were added to reduce the emission of sulfur oxides; low-cost corn & wheat biomass was blended with coal to utilized agricultural waste, and reduce the cost and ash content of the briquette. The thermal efficiency and the pollutants emission of this new stove were compared with the conventional one-chamber stove. The results revealed that the thermal efficiency of the stove was improved to 68%, compared with the conventional stove of 50%, while the emissions of sulfur dioxide, nitrogen oxides and carbon monoxide were reduced significantly. The coal biomass-briquette was demonstrated to be excellent in sulfur dioxide retention compared with other types of local coal. In addition, a significant reduction in the indoor concentration of carbon monoxide and PM using coal biomass-briquette in the new stove was confirmed. Information from this study demonstrates the high thermal efficiency and environment-friendly feature of the newly designed coal stove and the coal biomass-briquette. This new clean coal technology has been successfully demonstrated in two counties of Shanxi Province in China, and has great potential for improving regional and indoor air quality.