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 (∼1011 particles per useful energy delivered, particles/MJd), and kerosene (∼1013 particles/MJd), produced emissions that were lower by 2-3 orders of magnitude than solid fuels (1014-1015 particles/MJd). Three different PNSD types-unimodal distributions with peaks ∼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 (F30) 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 F30 (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 F30 value of approximately 73-80%.

An investigation of micro-hollow cathode glow discharge generated optical emission spectroscopy for hydrocarbon detection and differentiation.

The analytical utility of a micro-hollow cathode glow discharge plasma for detection of varied hydrocarbons was tested using acetone, ethanol, heptane, nitrobenzene, and toluene. Differences in fragmentation pathways, reflecting parent compound molecular structure, led to differences in optical emission patterns that can then potentially serve as signatures for the species of interest. Spectral simulations were performed emphasizing the CH (A(2)Δ-X(2)Π), CH (C(2)Σ-X(2)Π), and OH (A(2)Σ(+)-X(2)Π) electronic systems. The analytical utility of selected emission lines is demonstrated by a linear relationship between optical emission spectroscopy and parent compound concentration over a wide range, with detection limits extending down to parts per billion (ppb) levels.