Grantee Research Project Results

Atmospheric Transformation of Volatile Organic Compounds: Gas-Phase Photooxidation and Gas-to-Particle Conversion

EPA Grant Number: R824970C003
Subproject: this is subproject number 003 , established and managed by the Center Director under grant R824970
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: HSRC (1989) - Northeast HSRC
Center Director: Sidhu, Sukh S.
Title: Atmospheric Transformation of Volatile Organic Compounds: Gas-Phase Photooxidation and Gas-to-Particle Conversion
Investigators: Seinfeld, John , Flagan, Richard
Institution: Massachusetts Institute of Technology
Current Institution: California Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1992 through May 31, 1997
Project Amount: Refer to main center abstract for funding details.
RFA: Center on Airborne Organics (1993) Recipients Lists
Research Category: Targeted Research

Objective:

The objective of this project is to gain a better fundamental understanding of the atmospheric oxidation of volatile organic compounds (VOCs) important in urban and regional air quality. Specific aims are to determine the gas-phase mechanisms of reaction of important VOCs with the hydroxyl radical, the atmosphere's most ubiquitous oxidizing species, and to elucidate the mechanisms of formation of organic aerosols from the atmospheric oxidation of VOCs.

Approach:

The integrated research program to determine the mechanisms of photooxidation and secondary organic aerosol formation in the atmosphere for a number of important anthropogenic and biogenic hydrocarbons is carried out in both indoor and outdoor reactors. Experiments in the indoor reactor are used to probe chemical mechanisms. The large outdoor smog chamber is employed to study the integrated gas-phase and gas-to-particle conversion dynamics.

Rationale:

Gas-to-particle conversion is a ubiquitous process in the atmosphere, determining the size and composition of particles from the polluted urban atmosphere to the remote marine boundary layer. Understanding the detailed chemistry and physics of atmospheric gas-to-particle conversion will allow us to predict the effects of primary gaseous and particulate emissions changes on airborne particulate matter, in the urban and regional setting, and the effects of sulfur and other species on the generation of cloud condensation nuclei in the remote atmosphere. A principal goal of the research program is the development of comprehensive air quality models based on the most complete description of atmospheric chemistry and physics. These models are forerunners of those that will eventually be used in the regulatory process. This research is aimed at developing the organic portion of advanced gas-aerosol models, and to advance the current state of understanding of molecular processes. The component of the proposed research on gas-phase photooxidation chemistry has the goals of adding to the body of kinetic and mechanistic data for atmospheric organics, with particular emphasis on those VOCs that are potential aerosol precursors.

Supplemental Keywords:

VOC, atmosphere, air., RFA, Scientific Discipline, Air, Waste, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Physics, Environmental Chemistry, Fate & Transport, Atmospheric Sciences, fate and transport, ambient air quality, particulates, chemical characteristics, photooxidation, air quality models, gas to particle conversion, atmospheric transformation, chemical kinetics, atmospheric transport, Volatile Organic Compounds (VOCs)

Progress and Final Reports:

Main Center Abstract and Reports:

R824970 HSRC (1989) - Northeast HSRC

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R824970C001 Chemical Kinetic Modeling of Formation of Products of Incomplete Combustion from Spark-ignition Engines
R824970C002 Combustion Chamber Deposit Effects on Engine Hydrocarbon Emissions
R824970C003 Atmospheric Transformation of Volatile Organic Compounds: Gas-Phase Photooxidation and Gas-to-Particle Conversion
R824970C004 Mathematical Models of the Transport and Fate of Airborne Organics
R824970C005 Elementary Reaction Mechanism and Pathways for Atmospheric Reactions of Aromatics - Benzene and Toluene
R824970C006 Simultaneous Removal of Soot and NOx from the Exhaust of Diesel Powered Vehicles
R824970C007 Modeling Gas-Phase Chemistry and Heterogeneous Reaction of Polycyclic Aromatic Compounds
R824970C008 Fundamental Study on High Temperature Chemistry of Oxygenated Hydrocarbons as Alternate Motor Fuels and Additives
R824970C009 Markers for Emissions from Combustion Sources
R824970C010 Experimental Investigation of the Evolution of the Size and Composition Distribution of Atmospheric Organic Aerosols
R824970C011 Microengineered Mass Spectrometer for in-situ Measurement of Airborne Contaminants

Top of Page

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.