The impact of oxygen content in the primary air supply on fuel burning rate and pollutant emissions in a forced-draft biomass stove

•Six O2 content levels in air supply were tested for a forced-draft biomass stove.•The average burning rate had a positive linear relationship with O2 content.•CO, NOx, and PM2.5 emissions varied with O2 content.•The real-time burning rate and pollutant emission rates exhibited different trends.•An O2 content of 19.7% was recommended for household biomass stoves.