Emissions of air pollutants from household stoves: honeycomb coal versus coal cake

Environ Sci Technol. 2004 Sep 1;38(17):4612-8. doi: 10.1021/es049942k.


Domestic coal combustion can emit various air pollutants. In the present study, we measured emissions of particulate matter (PM) and gaseous pollutants from burning a specially formulated honeycomb coal (H-coal) and a coal cake (C-coal). Flue gas samples for PM2.5, PM coarse (PM2.5-10), and TSP were collected isokinetically using a cascade impactor; PM mass concentrations were determined gravimetrically. Concentrations of SO2, NOx, and ionic Cr(VI) in PM were analyzed using spectrometric methods. Fluoride concentrations were measured using a specific ion electrode method. PM elemental components were analyzed using an X-ray fluorescence technique. Total (gas and particle phase) benzo[a]pyrene (BaP) concentration was determined using an HPLC/fluorescence method. Elemental and organic carbon contents of PM were analyzed using a thermal/optical reflectance technique. The compositional and structural differences between the H-coal and C-coal resulted in different emission characteristics. In generating 1 MJ of delivered energy, the H-coal resulted in a significant reduction in emissions of SO2 (by 68%), NOx (by 47%), and TSP (by 56%) as compared to the C-coal, whereas the emissions of PM2.5 and total BaP from the H-coal combustion were 2-3-fold higher, indicating that improvements are needed to further reduce emissions of these pollutants in developing future honeycomb coals. Although the H-coal and the C-coal had similar emission factors for gas-phase fluoride, the H-coal had a particle-phase fluoride emission factor that was only half that of the C-coal. The H-coal had lower energy-based emissions of all the measured toxic elements in TSP but higher emissions of Cd and Ni in PM2.5.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Air Pollutants / analysis*
  • Air Pollution, Indoor / analysis*
  • Benzo(a)pyrene / analysis
  • Chromium Compounds / analysis
  • Coal* / analysis
  • Fluorides / analysis
  • Household Articles
  • Nitrogen Oxides / analysis
  • Particle Size
  • Sulfur Dioxide / analysis


  • Air Pollutants
  • Chromium Compounds
  • Coal
  • Nitrogen Oxides
  • Sulfur Dioxide
  • Benzo(a)pyrene
  • Fluorides