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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) 2007 Fuels and Emissions Conference 116.
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 NOx formation without increasing the emissions of HC. Even so, the best commercially... (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)
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author
; ; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
EGR, lean-burn, stoichiometric, Natural gas, hydrogen
host publication
SAE Transactions Journal of Enginges
volume
116
article number
2007-01-0015
edition
3
publisher
Society of Automotive Engineers
conference name
2007 Fuels and Emissions Conference
conference location
Cape Town, South Africa
conference dates
2007-01-23 - 2007-01-25
external identifiers
  • scopus:85072437236
ISBN
978-0-7680-1982-7
DOI
10.4271/2007-01-0015
project
Competence Centre for Combustion Processes
language
English
LU publication?
yes
id
2b8bf9db-0679-42a0-a0fb-1a222ffab2a4 (old id 538690)
date added to LUP
2016-04-04 11:44:12
date last changed
2020-10-27 02:31:25
@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 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<br/>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.},
  author       = {Saanum, Inge and Bysveen, Marie and Tunestål, Per and Johansson, Bengt},
  booktitle    = {SAE Transactions Journal of Enginges},
  isbn         = {978-0-7680-1982-7},
  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},
  url          = {https://lup.lub.lu.se/search/ws/files/5843172/625870.pdf},
  doi          = {10.4271/2007-01-0015},
  volume       = {116},
  year         = {2007},
}