Combustion chemical kinetics of biodiesel and related compounds (methyl and ethyl esters): Experiments and modeling – Advances and future refinements

The motivation for and challenges in reducing the world's dependence on crude oil while simultaneously improving engine performance through better fuel efficiency and reduced exhaust emissions have led to the emergence of new fuels and combustion devices. Over the past ten years, considerable effort has gone into understanding combustion phenomena in relation to emerging fuel streams entering the market. The present article focuses specifically on one typical emerging transportation fuel dedicated to the diesel engine, biodiesel, with an emphasis on ethyl esters because of recently renewed interest in its use as a completely green biofuel. Based on a review of the research developments over the past ten years in advanced experimental and kinetic modeling related to the oxidation of biodiesel and related components, the main gaps in the field are highlighted to facilitate the convergence toward clean and efficient combustion in diesel engines. After briefly outlining the synergy between “feedstocks – conversion process – biodiesel combustion”, the combustion kinetics of methyl and ethyl biodiesels are reviewed with emphasis on two complementary aspects: mechanism generation based on a detailed chemical kinetic approach that leads to predictive combustion models and experimental combustion devices that generate the data required during the development and validation of the predictive models.