Effects of moisture content in fuel on thermal performance and emission of biomass semi-gasified cookstove

• The effect of moisture content (MC) in fuel on the performance of semi-gasified cookstove was studied.
• Two calculation methods led to the same variation trends but different values of thermal efficiencies.
• The increase of MC in fuel significantly reduced CO and PM2.5 emissions.

As the dissemination of improved biomass cookstoves is an ongoing activity, studying the parameters that affect stove performance is important. The objective of this study was to investigate the effect of moisture content (MC) in fuel on stove performance. Wood pellets with MC of 5.9%, 9.4%, 18.2%, and 22.1% were processed and used as fuel in the test. A natural-draft semi-gasified cookstove was employed in this study. Two methods of thermal efficiency calculations were adopted in this study and the results were compared. It was observed that the burning rate, cooking power, and CO and PM2.5 emission factors all decreased with the increase of MC in fuel, and the impacts were all statistically significant (p < 0.05), while the ratio of quantity of charcoal produced to the quantity of dry fuel stayed at around 26%–27%. The results obtained in this study provided us useful information on the effects of MC in fuel on the performance of a semi-gasified cookstove in the lab and in the field.