Estimates of Organic Particle Composition from Condensable VOCs Using the Canadian Emissions Processing System

摘要

The potential contribution of emitted condensable gases to the mass of organic aerosols has been estimated for summer and winter seasons through the use of an emissions processing system, a new detailed VOC speciation, and iterative thermodynamic calculations. The potential contribution of these species to total aerosol loading was found to be significant, with values across an eastern North America grid ranging from 0.1 ug/m~3 over large portions of the grid to over 40 ug/m~3 in isolated "hot-spots" of high emissions of specific VOCs. High-carbon-number alkanes, low-vapour-pressure PAHs, diacids, and dialkyl phthalates were the classes of compounds having the greatest contribution to the total organic aerosol mass. The calculations indicate that certain VOCs that are emitted as gases will condense directly to the aerosol phase without oxidation. Emissions speciations and reaction mechanisms lacking this level of VOC detail will fail to reproduce this source of organic aerosol mass.