Development of a forced draft gasifier stove with optimized insulation and airflow rates: an experimental study

Solid biomass is extensively used in many developing nations especially, for cooking and heating applications using traditional technologies, resulting in the emission of several health hazardous pollutants into the environment. However, proper air-to-fuel ratio can be maintained by small fans particularly in the cookstove making it forced draft which could be promising in lowering the emissions of these pollutants. This article presents the effects of primary as well as secondary airflow rates on various performance parameters, including thermal efficiency, fuel consumption rate, power output, CO, NO, PM2.5, and combustion zone temperature of a forced draft gasifier stove. The study was carried out following the Bureau of Indian Standards while utilizing biomass pellets as a source of energy. The experimental results indicated that the thermal efficiency decreased gradually with increased secondary airflow rates. At the same time, the emissions of CO and PM2.5 exhibited a U-shaped trend, i.e. first decreased and thereafter increased at each primary airflow rate. However, NO's emissions first increased and subsequently decreased with further increment in secondary airflow rate. It was found from the experimental investigation that the ratio of primary to secondary air of 4:6 led to the least emissions of CO and PM2.5 when the primary and secondary airflow rates were varied in the range of 0.003–0.005 kg/s and 0.003–0.009 kg/s, respectively. The emission factors of CO and PM2.5 from the developed gasifier stove at optimized airflow rates were estimated to be around 1.7 and 0.11 g/kgfuel, while these values were 16.7 and 0.43 g/kgfuel for LPG stove.Graphical abstract