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dc.contributor.advisorSarathy, Mani
dc.contributor.authorAl Ashkar, Youssef
dc.date.accessioned2022-07-25T07:01:35Z
dc.date.available2022-07-25T07:01:35Z
dc.date.issued2022-07
dc.identifier.citationAl Ashkar, Y. (2022). The Effects of Gasoline Composition and Additive Concentration on the Lubricity of Gasoline Blends [KAUST Research Repository]. https://doi.org/10.25781/KAUST-8CYH1
dc.identifier.doi10.25781/KAUST-8CYH1
dc.identifier.urihttp://hdl.handle.net/10754/679857
dc.description.abstractUnder current regulations, gasoline engines are facing lubricity and wear challenges that need to be met by enhanced gasoline lubricity. Gasoline lubricity can be enhanced by lubricity improvers such as heavy fatty acid methyl esters. This thesis presents the ‘High Frequency Reciprocating Rig’ (HFRR) tests carried out on a standardized tribological test rig as per a modified version of ASTM D6079, to account for the effects of volatility of gasoline. Testing 5 gasoline types (gasolines A-E) blended with 2 lubricity improver types (LI1-2) at 2 concentrations, 250 and 500 ppm, provided insights on the changes in lubrication behavior with different gasoline composition, LI type, and concentration. The gasoline types with higher aromatic content and average carbon number (lower volatility) resulted in less wear and better lubricity regardless of LI concentration. The highly aromatic gasoline “A” performed better with the fatty acid-based LI1. Gasolines “B-E”, which are less aromatic, resulted in less wear with the ester-based LI2. The decrease in wear volumes with LI2 was more pronounced with the highly volatile gasolines B and E. These insights were mainly challenged by the failure of some tests due to the high volatility of gasoline. To mitigate this effect and confirm the findings, less volatile gasoline surrogates were designed to mimic the composition of the gasoline types on functional group basis, and were blended with the same lubricity improvers, and then tested using the same method. This improved the results and showed that high aromaticity enhanced the lubricity of the gasoline blends, especially with fatty-acid based LI1, but degraded it beyond 50% aromatic content. The enhancement of lubricity with higher average carbon number was also highlighted. To create deeper understanding of the lubrication mechanisms involved, it is recommended to study the rheological properties of the blends, analyze the chemical composition of the deposits on the wear tracks, and repeat the tests with continuous supply of lubricant to further decrease the effect of gasoline volatility
dc.language.isoen
dc.subjectLubricity
dc.subjectAdditive
dc.subjectVolatility
dc.subjectAromaticity
dc.subjectWear
dc.subjectFriction
dc.titleThe Effects of Gasoline Composition and Additive Concentration on the Lubricity of Gasoline Blends
dc.typeThesis
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.rights.embargodate2023-07-25
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberRoberts, William L.
dc.contributor.committeememberSzekely, Gyorgy
thesis.degree.disciplineChemical Engineering
thesis.degree.nameMaster of Science
dc.identifier.orcid0000-0003-2466-8315
dc.rights.accessrightsAt the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis will become available to the public after the expiration of the embargo on 2023-07-25.
refterms.dateFOA2022-07-25T07:01:35Z
kaust.request.doiyes
kaust.gpclinda.sapolu@kaust.edu.sa
kaust.availability.selectionEmbargo the work for one year and then release for public access* on the internet through the KAUST Repository.
kaust.thesis.advisorApprovalRequestedYes, I have already submitted the final approval form to my advisor.


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