Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Automated Construction of Pressure-Dependent Gas-Phase Kinetic Models: New Pathways for Old Problems



D M. Matheu, M Saeys, J M. Grenda, A M. Dean, W H. Green


Advancement in the understanding and design of such important gas-phase processes as light hydrocarbon cracking, combustion, and partial oxidation hinges, in part, on the development of correct, detailed chemical kinetic models. These kinetic models may have thousands of individual chemical reaction steps, and many hundreds of species, along with attendant information on thermochemistry and rates of reaction. But the very size and complexity of the required chemical mechanisms makes them extremely difficult to construct correctly by hand. Chemists and engineers have thus turned to software tools that attempt to build these large mechanisms automatically. Unfortunately, none of these tools can properly treat the pressure-dependence of certain reaction steps and a great many systems of industrial importance have at least some pressure-dependent reactions. This has technically limited large, automatically-generated chemical mechanisms to a narrow region called the high-pressure limit. Furthermore, most of these tools do not systematically terminate the otherwise combinatorial growth of a computer-generated chemical mechanism, requiring the use of arbitrary criteria for deciding when mechanism growth is complete.We present a new, elementary-step-based mechanism generation algorithm which combines an integrated approach to pressure-dependent reactions with a rational, flux-based criteria for truncating mechanism growth. Applications to difficult problems in methane and high-conversion ethane pyrolysis, which could not be addressed by hand, and which include important pressure-dependent phenomena, reveal important new pathways not previously considered by other researchers. These reaction pathways can explain the experimentally observed behavior. An example including steam-cracking of ethane reveals certain pathways to minor species (thought to be important for the formation of coke and soot) to be pressure-dependent. The rational criteria for limiting mechanism growth gives us confidence that all the important pathways have been discovered and captured by our software.
Proceedings Title
Sigma Xi Postdoctoral Poster Presentations, 2004
Conference Dates
February 19-20, 2004


automated, construction, gas-phase, kinetic models, pathways, pressure-dependent


Matheu, D. , Saeys, M. , Grenda, J. , Dean, A. and Green, W. (2004), Automated Construction of Pressure-Dependent Gas-Phase Kinetic Models: New Pathways for Old Problems, Sigma Xi Postdoctoral Poster Presentations, 2004 (Accessed July 16, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created February 1, 2004, Updated February 17, 2017