Pellet-fed gasifier stoves approach gas-stove like performance during in-home use in Rwanda

Nearly all households in Rwanda burn solid fuelsfor cooking. A private firm in Rwanda is distributing forced-draft pellet-fed semi-gasifier cookstoves and fuel pellets. We measured in-use emissions of pollutants including fine particulate matter (PM2.5), organic and elemental carbon (OC, EC), black carbon(BC) and carbon monoxide (CO) in 91 uncontrolled cooking tests (UCTs) of both pelletand baseline (wood; charcoal) stoves. We observed >90% reductions in most pollutant emission factors/rates from pellet stovescompared to baseline stoves. Pellet stovesperformed far better than gasifier stovesburning unprocessed wood, and consistent with ISO tiers 4 and 5 for PM2.5 and CO, respectively. Pellet stoveswere generally clean, but performance varied; emissions from the dirtiest pellettests matched those from the cleanest traditional stovetests. Our real-time data suggest that events occurring during ignition and the end of testing (e.g., refueling, char burnout) drive high emissions during pellettests. ...