Hydrocarbon emissions from natural gas engines

A summary of research during the Ph.D. study of Anders Broe Bendtsen

Natural gas engines are a widespread method for heat and power co-generation. They do, however, have a significant emission of methane, which is a potent green house gas. Little is known about the post cylinder processes, and therefore this project has set out to analyse the chemistry of methane oxidation at moderate temperatures. The development of new models has included a novel and fruitful interaction between conventional chemical engineering methods and a chemometrics approach.

A chemometric investigation of pilot scale engine results has shown that an interaction between NOx and CH4 oxidation exists. This result was confirmed by laboratory experiments, but could not be described satisfactorily by existing kinetic models. (See poster)

Based on an existing reaction set the reaction mechanism behind NOx enhanced methane oxidation was studied. (See poster) During this study new visualization techniques were developed which help identifying the important reaction paths in a reaction mechanism. These visualization techniques were based on scaling of sensitivity coefficients, principal component analysis of rate of production matrices and automatic generation of pathway plots. (Download program)

With the aid of these visualization tools a detailed chemical kinetics model was developed which was able to describe the phenomena observed in the laboratory experiments. This model has also been used to describe pilot scale experiments.

To discuss the thesis e-mail the author Anders Broe Bendtsen, andbbdk@gmail.com

To request a copy of the thesis e-mail CHEC, chec@kt.dtu.dk


Publications prepared during the study:

Bendtsen A.B., & P. Glarborg. (1998) Prediction of Reaction Rate Constants. 55‑60. Fashioning a Model: Optimization Methods in Chemical Physics. Durham,UK

Bendtsen A.B., P. Glarborg, & K. Dam‑Johansen. (1998) Chemometric Analysis of a Detailed Chemical Reaction Mechanism for Methane Oxidation. Chemom.Intell.Lab.Syst. 44, 357‑365

Bendtsen A.B., P. Glarborg, K. Dam‑Johansen, P.G. Kristensen, & B. Karll. (1998) NOx Sensitised Oxidation of Methane ‑ Experiments and Modelling. WIP Poster. W2A05 27th Symposium (Int.) on Combustion. 1998; The Combustion Institute Pittsburgh, PA, USA

Bendtsen A.B., P. Glarborg, & K. Dam‑Johansen. (1998) Identification of Missing Reactions in Detailed Reaction Mechanisms. WIP Poster. W5B15 27th Symposium (Int.) on Combustion. 1998; The Combustion Institute Pittsburgh, PA, USA

Bendtsen A.B., P. Glarborg, & K. Dam‑Johansen. (2000) Low temperature oxidation of methane: The influence of nitrogen oxides. Combust. Sci. and Tech. 151, 31-71

Glarborg P., A.B. Bendtsen, & J.A. Miller. (1999) Nitromethane dissociation. Implications for the CH3+NO2 reaction.  Int.J.Chem.Kin. 31, 591-602

Bendtsen A.B., P. Glarborg, & K. Dam‑Johansen. (2001) Visualization methods in analysis of detailed chemical kinetics modelling. Comp.Chem. 25, 161


Author Anders Broe Bendtsen,

Last updated: February 19th 2001