Chemical Characterization of Emissions Arising from Solid Fuel Combustion—Contrasting Wood and Cow Dung Burning

Abstract

Biomass burning is a dominant source of ultrafine particulate matter in the atmosphere. Particulate matter is a leading health risk factor on a global scale, causing millions of premature deaths annually. Biomass burning also emits short-term climate forcers which contribute to the warming of the Earth’s atmosphere. Wood and animal dung are widely employed in the developing world as the primary sources of household energy. While wood burning is well studied, emissions from dung remain largely uncharacterized. Emissions from a given burn are highly complex chemical mixtures. While specific biomass tracerssuch as levoglucosanare employed to track burns, a fundamental chemical understanding of biomass emissions is required to predict their impacts. Herein, we conducted comprehensive sets of chemical analyses for particles emitted from biomass burning. Samples were generated using a tube furnace allowing reproducible, precise control of conditions. Emission factor data for levoglucosan and its isomers were measured from extracted particulate matter. We found that the levoglucosan emission factors from two distinct types of cow dung were consistently lower than that from wood. The water-extractable fraction of dung emissions exhibited light-absorptive properties greater than wood. Nontargeted chemical characterization was achieved through deconvolution of high-resolution mass spectrometry data. Overall, we present that the key differences between wood and dung emissions mirror the differences in their fuel compositions. The complexity of the extracted spectra and the unique characteristics of dung emissions accentuate the need for further study on biomass types less common within the Western context.

Aqueous-phase photochemical oxidation of water-soluble brown carbon aerosols arising from solid biomass fuel burning

“…The pyrolysis of these components produces BrC chromophores such as phenols, nitrophenols, organic acids, etc., that are highly prevalent in the ambient atmosphere. 28,[36][37][38][39] Therefore, BrC aerosol particles were generated by the pyrolysis of the above-mentioned solid biomass fuels in a tube furnace, using the method described in Loebel Roson et al, 37 in an aerobic atmosphere. Briey, a small amount (<1 g) of each solid biomass fuel was placed in a quartz tube (internal diameter = 1 2 inch) inside of a tube furnace (Carbolite Gero) and heated at a temperature of 500 °C.…”

Formation of insoluble brown carbon through iron-catalyzed reaction of biomass burning organics

“…References are presented in cases where structural assignments have been made in previous studies. 5,30,38,42–55 Fig. 5 shows the total ion chromatograms of all temperature OA, with peaks labeled according to their corresponding detected ion in Table S2 †.…”

Unexpected Electrophiles in the Atmosphere - Anhydride Nucleophile Reactions and Uptake to Biomass Burning Emissions

“…Samples were collected as previously described in Loebel Roson et al, 13 briefly, a tube furnace was used to reproducibly burn and collect wood (lodgepole pine) biomass burning emissions on pre-baked 0.22 µm pore size quartz fiber filters. After collection, whole filters were extracted in 10 or 20 mL of ACN using a magnetic stirrer for 40 minutes.…”

“…[48][49][50] The chosen nucleophilic species (referred to further as nucleophiles) represent only a few of the major emissions from biomass burning, and were selected due to their previous detection in Loebel Roson et al. 13 Levoglucosan (99%, Sigma Aldrich), coniferyl aldehyde (98%, Sigma Aldrich), anisyl alcohol (98%, Sigma Aldrich), and vanillin (99%, ReagentPlus, Sigma Aldrich) are all common biomass burning tracers which represent a variety of functional groups and molecular properties. 10,28,34,35,51 Histidine (99%, ReagentPlus, Sigma Aldrich) is an essential amino acid present in animal dung, which is used as fuel for cooking and heating in numerous developing countries.…”

“…While the commonly -and relatively high abundanceemitted compounds are well established (such as cellulose and hemicellulose decomposition products), the largest fraction represented by numerous low-intensity species, is not. 3,[8][9][10][11][12][13] Convoluting things further, primary organic aerosol will physically and chemically evolve in the atmosphere. Through reactions occurring inside particles, as well as interactions with gas-phase molecules, its composition and effects are additionally modified.…”