A Laboratory Comparison of Emission Factors, Number Size Distributions, and Morphology of Ultrafine Particles from 11 Different Household Cookstove-Fuel Systems

Ultrafine particle (UFP) emissions and particle number size distributions (PNSD) are critical in the evaluation of air pollution impacts; however, data on UFP number emissions from cookstoves, which are a major source of many pollutants, are limited. In this study, 11 fuel-stove combinations covering a variety of fuels and different stoves are investigated for UFP emissions and PNSD. The combustion of LPG and alcohol (similar to 10(11) particles per useful energy delivered, particles/MJ(d)), and kerosene (similar to 10(13) particles/MJ(d)), produced emissions that were lower by 2-3 orders of magnitude than solid fuels (10(14)-10(15) particles/MJ(d)). Three different PNSD types unimodal distributions with peaks similar to 30-40 nm, unimodal distributions with peaks <30 nm, and bimodal distributions were observed as the result of both fuel and stove effects. The fractions of particles smaller than 30 nm (F-30) varied among the tested systems, ranging 'from 13% to 88%. The burning of LPG and alcohol had the lowest PM2.5 mass emissions, UFP number emissions, and F-30 (13-21% for LPG and 35-41% for alcohol). Emissions of PM2.5 and UFP from kerosene were, also low compared with solid fuel burning but had a relatively high F-30 value of approximately 73-80%.