Abstract View
Modification and Optimization on Environmental Chamber Experiments of Secondary Organic Aerosol Formation from LVP-VOCs and Volatile Consumer Products to Improve Model Prediction
QI LI, Sophia Charan, Reina Buenconsejo, John Seinfeld, David R. Cocker III, University of California, Riverside
Abstract Number: 262
Working Group: Missing contributors to SOA: The Role of Volatile Chemical Products (VCPS)
Abstract
Recent studies show that non-vehicular sources such as volatile consumer products (VCPs) become to contribute a larger fraction of the total volatile organic compounds (VOCs) emissions in the urban areas than before. To better characterize the sources and evaluate their impacts on the ambient secondary organic aerosol (SOA) formation, in this study, a series of chamber experiments have been performed on a wide range of VCPs under urban relevant conditions. 12 VCPs-related VOCs (including some LVP-VOCs) are selected due to their high suspected potential on SOA formation and emission abundance. Experimental SOA formation data are presented from environmental experiments done under varying conditions of NOx, H2O2, and seed aerosol. Typical VCPs-related VOC benzyl alcohol shows a SOA yield of up to 60% at 291k, in the presence of H2O2, NOx, and ammonia sulfate seed (larger than previously reported 41% and 56% with surrogate). Well-controlled environmental chamber experiments are heavily relied for chemical mechanisms development. However, due to the features of the LVP-VOCs (low vapor pressure and high boiling point), environmental chamber studies with the LVP-VOCs can be hard. A detailed environmental chamber comparison between the UCR chamber and Caltech chamber has been performed to modify and optimize the experimental chamber experiments and refine the experimental protocol. The comparison and optimization have been done in various aspects including chamber construction features, instrument performance, experimental methods (including injection and sampling methods), and data analysis methods. Certain experiments performed under similar conditions in both chambers show a deduction of up to 60% in terms of the difference of the SOA yield before and after the optimization.