SAPRC Mechanism Generation System for the Atmospheric Reactions of Volatile Organic Compounds in the Presence of NOx
Prepared for the California Air Resources Board Contract No. 11-761
and the U.S. Environmental
Protection Agency Agreement No. 84000701
By
William P. L. Carter
Research Chemist Emeritus
College of Engineering, Center for Environmental
Research and Technology
University of California, Riverside, CA, USA
Mailing Address: CE-CERT, University of California,
Riverside, CA 92521
Phone: (951) 788-8425. FAX: (951) 781-5790
E-mail: carter@cert.ucr.edu
Description
The SAPRC mechanism generation system, or MechGen,
derives explicit mechanisms for the gas-phase reactions of many types
of volatile organic compounds and their oxidation products when they
react in the atmosphere in the presence of oxides of nitrogen and other
pollutants. It then optionally uses the results to derive lumped
mechanisms suitable for use in atmospheric models. This system was used to derive the SAPRC-22 chemical mechanism, which is the latest version of the SAPRC mechanisms.
However, its primary use for most researchers in basic or atmospheric chemistry would be to derive fully
explicit mechanisms that can be used for analyzing laboratory data or
predicting atmospheric fates organic compounds when they react in the
atmosphere.
MechGen is available online at http://mechgen.cert.ucr.edu,
and advanced users can also obtain their own copies to run on their own
computer. The following links can be used to obtain more information
about the system:
- The basic web users guide provides basic information on how to use the web system and is recommended for new users.
- The complete users manual describes
the capabilities of the system and how to use them, and provides the
most complete description of MechGen that is currentlyand currently
available.
- A manuscript describing
MechGen and its algorithms for peer reveiw is in preparation, and a
link to it will be available here once it is available.
- The online system provides
basic information on how anyone can create a free account log into the
system, and once logged in there are links that provide additional
information about how to use the system and also the chemical mechanism
estimates and assignments.
- A paper documenting the scientific basis of the
chemical estimation methods and assignments has been submitted is under
final peer review, but a preprint and reviewer comments are available online.
The users manual
also describes how interested advanced users can obtain their own copy
of MechGen for their own use. This is necessary if users who need to
carry out highly resources-intensive operations such as deriving
mechanisms for large numbers of compounds, or compounds with more than
9 carbons or structural groups. It can be installed on both Windows or
Unix or Linux based systems. The following files or links are available
for this purpose:
- MechGen.zip contains the database and all the programs and files needed to run MechGen on a windows-based system.
- Information how to install MechGen on Linux or Unix systems is available at the MechGen GitHub site.
- MechGen_v4_unix.db.tar.gz contains the current MechGen database suitable for installation on Linux or Unix systems.
- The Windows and Unix database files were updated
to correct minor errors on July 9, 2024
Please notify me at carter@cert.ucr.edu
if you want additional information, or encounter problems, errors, or
unreasonable mechanism results using MechGen. If you get a traceback,
please copy and send it to me, along with enough information so I can
duplicate it. I will then attempt to correct the errors, or at least
have the system give proper error messages if it cannot be corrected.
Page last modified July 10, 2024
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