Effect of Primary Air on Performance of a Natural Draft Dual-Purpose Gasifier Stove: An Experimental Study

Biochar production and household energy utilization have garnered considerable attention in developing nations worldwide for over a decade. Gasification-based cookstoves mitigate numerous issues related to conventional cooking methods while effectively producing biochar. The novelty of this work lies in utilizing the gasifier stove for biochar production while simultaneously offering a clean cooking solution that empowers the livelihood of the rural population. The present study is carried out to investigate the effects of primary airflow on the thermal performance and biochar yield of a natural draft gasification technology-based improved cookstove. The inlet area of primary air varies from 25 to 100% in increments of 25%, producing biochar samples BC 25, BC 50, BC 75, and BC 100. The produced biochar is further characterized by performing proximate and ultimate analysis, X-ray diffraction analysis, FTIR analysis, and BET surface area analysis. The developed cookstove exhibits thermal efficiency in the range of 26.96–28.52%, while the biochar yield varies between 15.2 and 20.4%. The emission of carbon monoxide calculated per unit useful energy delivered to the pot ranges from 2.48 to 3.89 g/MJ_D corresponding to various airflow rates of primary air. The calorific value and percentage carbon content in the produced biochar samples range between 7424 and 8329 kcal/kg and 84.42 and 86.82%, respectively. The surface area of the biochar sample is increased three times with the increment in the primary air inlet area from 25 to 100%.