Abstract
In order to meet stringent emission limits,
after-treatment systems are increasingly utilized in
natural gas engine applications. In this work, two
catalyst systems were studied in order to clarify how the
catalysts affect, e.g. hydrocarbons, NOx and particles
present in natural gas engine exhaust. A passenger car
engine modified to run with natural gas was used in a
research facility with possibilities to modify the
exhaust gas properties. High NOx reductions were observed
when using selective catalytic reduction, although a
clear decrease in the NOx reduction was recorded at
higher temperatures. The relatively fresh methane
oxidation catalyst was found to reach reductions greater
than 50% when the exhaust temperature and the catalyst
size were sufficient. Both the studied catalyst systems
were found to have a significant effect on particulate
emissions. The observed particle mass reduction was found
to be due to a decrease in the amount of organics passing
over the catalyst. However, especially at high exhaust
temperatures, high nanoparticle concentrations were
observed downstream of the catalysts together with higher
sulphate concentrations in particles. This study
contributes to understanding emissions from future
natural gas engine applications with catalysts in use.
Original language | English |
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Pages (from-to) | 142-152 |
Number of pages | 11 |
Journal | Emission Control Science and Technology |
Volume | 3 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jun 2017 |
MoE publication type | A1 Journal article-refereed |
Keywords
- natural gas
- engine emissions
- methane oxidation
- NOx reduction
- nanoparticles
- Nanoparticles
- NO reduction