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Lean burn versus stoichiometric operation with EGR and 3-way catalyst of an engine fueled with natural gas and hydrogen enriched natural gas

Saanum, Inge; Bysveen, Marie; Tunestål, Per LU and Johansson, Bengt LU (2007) In [Host publication title missing]
Abstract
Engine tests have been performed on a 9.6 liter spark-ignited engine fueled by natural gas and a mixture of

25/75 hydrogen/natural gas by volume. The scope of the

work was to test two strategies for low emissions of

harmful gases; lean burn operation and stoichiometric

operation with EGR and a three-way catalyst. Most gas

engines today, used in city buses, utilize the lean burn

approach to achieve low NOx formation and high thermal

efficiency. However, the lean burn approach may not be

sufficient for future emissions legislation. One way to

improve the lean burn strategy is to add hydrogen to the

fuel to increase the lean limit and thus reduce the... (More)
Engine tests have been performed on a 9.6 liter spark-ignited engine fueled by natural gas and a mixture of

25/75 hydrogen/natural gas by volume. The scope of the

work was to test two strategies for low emissions of

harmful gases; lean burn operation and stoichiometric

operation with EGR and a three-way catalyst. Most gas

engines today, used in city buses, utilize the lean burn

approach to achieve low NOx formation and high thermal

efficiency. However, the lean burn approach may not be

sufficient for future emissions legislation. One way to

improve the lean burn strategy is to add hydrogen to the

fuel to increase the lean limit and thus reduce the NOx

formation without increasing the emissions of HC. Even

so, the best commercially available technology for low

emissions of NOx, HC and CO today is stoichiometric

operation with a three-way catalyst as used in passenger cars. The drawbacks of stoichiometric operation are low thermal efficiency because of the high pumping work, low possible compression ratio and large heat losses. The recirculation of exhaust gas is one way to reduce these drawbacks and achieve efficiencies that are not much lower than the lean burn technology. The experiments revealed that even with the 25 vol% hydrogen mixture, NOx levels are much higher for the lean burn approach than that of the EGR and catalyst approach for this engine. However, a penalty in brake thermal efficiency has to be accepted for the EGR approach as the thermodynamic conditions are less

ideal. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
EGR, lean-burn, stoichiometric, Natural gas, hydrogen
in
[Host publication title missing]
publisher
Society of Automotive Engineers
external identifiers
  • scopus:84877219350
language
English
LU publication?
yes
id
2b8bf9db-0679-42a0-a0fb-1a222ffab2a4 (old id 538690)
alternative location
http://www.sae.org/technical/papers/2007-01-0015
date added to LUP
2007-09-25 09:19:52
date last changed
2017-09-10 04:57:24
@inproceedings{2b8bf9db-0679-42a0-a0fb-1a222ffab2a4,
  abstract     = {Engine tests have been performed on a 9.6 liter spark-ignited engine fueled by natural gas and a mixture of<br/><br>
25/75 hydrogen/natural gas by volume. The scope of the<br/><br>
work was to test two strategies for low emissions of<br/><br>
harmful gases; lean burn operation and stoichiometric<br/><br>
operation with EGR and a three-way catalyst. Most gas<br/><br>
engines today, used in city buses, utilize the lean burn<br/><br>
approach to achieve low NOx formation and high thermal<br/><br>
efficiency. However, the lean burn approach may not be<br/><br>
sufficient for future emissions legislation. One way to<br/><br>
improve the lean burn strategy is to add hydrogen to the<br/><br>
fuel to increase the lean limit and thus reduce the NOx<br/><br>
formation without increasing the emissions of HC. Even<br/><br>
so, the best commercially available technology for low<br/><br>
emissions of NOx, HC and CO today is stoichiometric<br/><br>
operation with a three-way catalyst as used in passenger cars. The drawbacks of stoichiometric operation are low thermal efficiency because of the high pumping work, low possible compression ratio and large heat losses. The recirculation of exhaust gas is one way to reduce these drawbacks and achieve efficiencies that are not much lower than the lean burn technology. The experiments revealed that even with the 25 vol% hydrogen mixture, NOx levels are much higher for the lean burn approach than that of the EGR and catalyst approach for this engine. However, a penalty in brake thermal efficiency has to be accepted for the EGR approach as the thermodynamic conditions are less<br/><br>
ideal.},
  author       = {Saanum, Inge and Bysveen, Marie and Tunestål, Per and Johansson, Bengt},
  booktitle    = {[Host publication title missing]},
  keyword      = {EGR,lean-burn,stoichiometric,Natural gas,hydrogen},
  language     = {eng},
  publisher    = {Society of Automotive Engineers},
  title        = {Lean burn versus stoichiometric operation with EGR and 3-way catalyst of an engine fueled with natural gas and hydrogen enriched natural gas},
  year         = {2007},
}