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Abstract. Emission of organic aerosol (OA) from wood combustion is not well constrained;understanding the governing factors of OA emissions would aid in explainingthe reported variability. Pyrolysis of the wood during combustion is theprocess that produces and releases OA precursors. We performed controlledpyrolysis experiments at representative combustion conditions. The conditionschanged were the temperature, wood length, wood moisture content, and woodtype. The mass loss of the wood, the particle concentrations, and light-gasconcentrations were measured continuously. The experiments were repeatable asshown by a single experiment, performed nine times, in which the real-timeparticle concentration varied by a maximum of 20 %. Highertemperatures increased the mass loss rate and the released concentration ofgases and particles. Large wood size had a lower yield of particles than thesmall size because of higher mass transfer resistance. Reactions outside thewood became important between 500 and 600 ∘C. Elevatedmoisture content reduced product formation because heat received was sharedbetween pyrolysis reactions and moisture evaporation. The thermophysicalproperties, especially the thermal diffusivity, of wood controlled thedifference in the mass loss rate and emission among seven wood types. Thiswork demonstrates that OA emission from wood pyrolysis is a deterministicprocess that depends on transport phenomena. 

Abstract. Oxidation flow reactors (OFRs) are an emerging tool for studying the formation and oxidative aging of organic aerosols and other applications.The majority of OFR studies to date have involved the generation of the hydroxyl radical (OH) to mimic daytime oxidative aging processes.In contrast, the use of the nitrate radical (NO3) in modern OFRs to mimic nighttime oxidative aging processes has been limited due to the complexity of conventional techniques that are used to generate NO3.Here, we present a new method that uses a laminar flow reactor (LFR) to continuously generate dinitrogen pentoxide (N2O5) in the gas phase at room temperature from the NO2 + O3 and NO2 + NO3 reactions.The N2O5 is then injected into a dark Potential Aerosol Mass (PAM) OFR and decomposes to generate NO3; hereafter, this method is referred to as “OFR-iN2O5” (where “i” stands for “injected”).To assess the applicability of the OFR-iN2O5 method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure, NO3:O3, NO2:NO3, and NO2:O2 as a function of LFR and OFR conditions.These parameters were used to investigate the fate of representative organic peroxy radicals (RO2) and aromatic alkyl radicals generated from volatile organic compound (VOC) + NO3 reactions, and VOCs that are reactive towards both O3 and NO3.Finally, we demonstrate the OFR-iN2O5 method by generating and characterizing secondary organic aerosol from the β-pinene + NO3 reaction.