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Influence of blends of diesel and renewable fuels on compression ignition engine emissions over transient engine conditions

Van Niekerk, Adriaan; Drew, Benjamin; Larsen, Neil; Kay, Peter


Benjamin Drew
Associate Professor in Mechanical & Motor Sport Engineering

Neil Larsen

Peter Kay
Acting Deputy Head of Department


© 2019 Elsevier Ltd To reduce the amount of carbon dioxide released from transportation the EU has implemented legislation to mandate the renewable content of petrol and diesel fuels. However, due to the complexity of the combustion process the addition of renewable content, such as biodiesel and ethanol, can have a detrimental effect on other engine emissions. In particular the engine load can have a significant impact on the emissions. Most research that have studied this issue are based on steady state tests that are unrealistic of real world driving and will not capture the difference between full and part loads. This study aims to address this by investigating the effect of renewable fuel blends of diesel, biodiesel and ethanol on the emissions of a compression ignition engine tested over the World Harmonised Light Vehicle Test Procedure (WLTP). Diesel, biodiesel and ethanol were blended to form binary and ternary blends, the ratios were determined by Design of Experiments (DoE). The total amount of emissions for CO, CO2 and NOx as well as the fuel consumption, were measured from a 2.4 L compression ignition (CI) engine running over the WLTP drive cycle. The results depicted that percentages smaller than 10% of ethanol in the fuel blend can reduce CO emissions, CO2 emissions as well as NOx emissions, but increases fuel consumption with increasing percentage of ethanol in the fuel blend. Blends with biodiesel resulted in minor increases in CO emissions due to the engine being operated in the low and medium load regions over the WLTP. CO2 emissions as well as NOx emissions increased as a result of the high oxygen content in biodiesel which promoted better combustion. Fuel consumption increased for blends with biodiesel as a result from biodiesel's lower heating value. All the statistical models describing the engine responses were significant and this demonstrated that a mixture DoE is suitable to quantify the effect of fuel blends on an engine's emissions response. An optimised ternary blend of B2E9 was found to be suitable as a ’drop in’ fuel that will reduce harmful emissions of CO emissions by approximately 34%, NOx emissions by 10% and CO2 emissions by 21% for transient engine operating scenarios such as the WLTP drive cycle.


Van Niekerk, A., Drew, B., Larsen, N., & Kay, P. (2019). Influence of blends of diesel and renewable fuels on compression ignition engine emissions over transient engine conditions. Applied Energy, 255, Article 113890.

Journal Article Type Article
Acceptance Date Sep 7, 2019
Online Publication Date Sep 18, 2019
Publication Date Dec 1, 2019
Deposit Date Sep 23, 2019
Publicly Available Date Sep 19, 2020
Journal Applied Energy
Print ISSN 0306-2619
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 255
Article Number 113890
Public URL


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