Strategies for improving premixed oxy-fuel combustion in spark-ignition engines

[EN] Oxy-fuel combustion in internal combustion engines is a promising technology that eases Carbon Capture and Storage and allows near-zero NOx powerplants. While some experimental and theoretical studies on oxyfuel combustion engines are available in the literature, there is a lack of systematic r...

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Bibliographic Details
Authors: Raggi, R., Gómez-Soriano, Josep|||0000-0002-2742-9224, Martín, Jaime|||0000-0002-0496-3176, Novella Rosa, Ricardo|||0000-0002-5123-6924
Format: article
Publication Date:2026
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:dnet:riunet______::1c6f1fb74457f30c63ad706e54a8d08d
Online Access:https://riunet.upv.es/handle/10251/233929
Access Level:Open access
Keyword:Oxy-fuel combustion
Efficiency
Carbon capture
MIEC
Zero NOx
CO2 capture
Description
Summary:[EN] Oxy-fuel combustion in internal combustion engines is a promising technology that eases Carbon Capture and Storage and allows near-zero NOx powerplants. While some experimental and theoretical studies on oxyfuel combustion engines are available in the literature, there is a lack of systematic research on dilution strategies or on the use of non-synthetic exhaust gas recirculation. This study uses a combination of 0D-1D and CFD modeling and experimental measurements to assess the use of oxygen dilution and real exhaust gas recirculation in a single-cylinder spark-ignition engine operation under oxy-fuel combustion conditions. A comparison between conventional and oxy-fuel combustion is first performed to highlight the differences between the two combustion modes. Later, taking into account the thermo-mechanical limitations and knocking restrictions, several strategies are analyzed to improve oxy-fuel combustion efficiency: exhaust gas recirculation ratio, compression ratio, and intake temperature. Results show that under oxy-fuel mode, operating at stoichiometric conditions with exhaust gas recirculation rates around 70%, reduces NOx by more than 99%, and CO and uHC by up to 89% compared to conventional combustion with air. In terms of performance, an 8 pp reduction in gross indicated efficiency could be expected; however, since knocking propensity is reduced, the compression ratio can be increased to recover about 5 pp of the efficiency drop.