Grantee Research Project Results

Elementary Reaction Mechanism and Pathways for Atmospheric Reactions of Aromatics - Benzene and Toluene

EPA Grant Number: R824970C005
Subproject: this is subproject number 005 , 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: Research Consortium on Ozone and Fine Particle Formation in California and in the Northeastern United States
Center Director: Seinfeld, John
Title: Elementary Reaction Mechanism and Pathways for Atmospheric Reactions of Aromatics - Benzene and Toluene
Investigators: Bozzelli, Joseph W. , Lay, Tsan
Institution: New Jersey 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:

Develop a model based on elementary reaction kinetics, pathways and thermodynamic properties which includes microscopic reversibility to understand and describe the photochemical oxidation of aromatic hydrocarbons (benzene, toluene, etc.) under atmospheric conditions. The reaction mechanism will be validated against experimental data in the literature.

Approach:

Reaction mechanisms utilize elementary kinetic parameters coupled with microscopic reversibility and include calculation of steady state levels of active intermediates. Pressure dependent and chemical activation reaction paths are included. Thermodynamic properties and transition state parameters are determined via literature evaluation, group additivity, and ab initio molecular orbital methods. Fundamental principles of thermochemical kinetics and detailed balance are applied to all reactions. Models are validated against literature experimental data.

Rationale:

At present there is insufficient kinetic data and no mechanism for modeling atmospheric reactions of aromatic compounds in photochemical, oxidation or other reaction systems. Development and validation of a mechanism will enable models pertaining to photochemical smog, air-shed transport and oxidation processes, to incorporate aromatic species. It will also provide a an understanding of atmospheric reactions and product formation rates on aromatic moieties.

Supplemental Keywords:

atmosphere, reaction, pathways, model., RFA, Scientific Discipline, Toxics, Air, Waste, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Physics, Environmental Chemistry, Fate & Transport, Atmospheric Sciences, tropospheric ozone, 33/50, particulates, elementary reaction kinetics, fate and transport, Toluene, ambient measurement methods, photooxidation, ambient air, atmospheric transformation, benzene, photochemical smog, aromatics, chemical transport model, chemical kinetics, atmospheric transport, modeling studies, atmospheric chemistry, thermodynamics

Progress and Final Reports:

Main Center Abstract and Reports:

R824970 Research Consortium on Ozone and Fine Particle Formation in California and in the Northeastern United States

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

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