Lesson 1Naphthenes (cycloalkanes): structures (cyclohexane, methylcyclopentane), occurrence in naphtha/kerosene, uses and effects on fuel propertiesCovers cycloalkane structures and conformations, focusing on cyclohexane and methylcyclopentane. Examines their occurrence in naphtha and kerosene, refinery formation routes, and influence on density, octane, and smoke point.
Cycloalkane structures and conformationsCyclohexane and methylcyclopentane examplesOccurrence in naphtha and kerosene cutsRefinery processes forming naphthenesEffects on octane, density and smoke pointLesson 2Olefins (alkenes): sources (cracking units), examples (ethylene, propylene, butenes), reactivity, impact on stability and polymer feedstock useExamines olefin structures, sources from cracking units, and examples such as ethylene, propylene and butenes. Discusses high reactivity, gum and deposit formation, and their value as polymer and petrochemical feedstocks.
Structural features of olefins and isomersSteam and fluid catalytic cracking sourcesEthylene, propylene and butenes examplesReactivity, oxidation and gum formationPolymer and petrochemical feedstock rolesLesson 3Isoparaffins (branched alkanes): structural features, examples (iso-octane), origin in fractions and catalytic reforming, importance for gasoline octaneFocuses on isoparaffins, their branched structures and examples like iso-octane. Explains formation in isomerisation and reforming units, and why they are central to high-octane, low-knock petrol formulations.
Structural features of branched alkanesIso-octane as an octane reference fuelIsomerization and reforming formation pathsVolatility and combustion of isoparaffinsUse in premium and reformulated gasolinesLesson 4Paraffins (n-alkanes): general formula, representative molecules (n-pentane, n-octane), refinery sources and major usesIntroduces normal paraffins, their general formula, and homologous series. Reviews key molecules such as n-pentane and n-octane, their boiling ranges, refinery sources, and roles in petrol, kerosene, diesel and wax streams.
General formula and homologous series conceptPhysical trends across n-alkane seriesRepresentative n-pentane and n-octane usesRefinery units producing normal paraffinsRoles in gasoline, diesel and wax productsLesson 5Cetane number fundamentals: molecular features that raise or lower cetane and relevance to diesel ignition qualityExplores cetane number as a diesel ignition quality index, linking molecular structure to ignition delay. Discusses normal paraffins, branching, rings, aromatics, and additives, plus test methods and typical specification ranges.
Definition and significance of cetane numberNormal paraffins and high cetane behaviorBranching, rings, aromatics and low cetaneCetane improver additives and treat ratesEngine and CFR test methods for cetaneLesson 6Analytical methods for molecular-class determination: GC, simulated distillation (SIMDIS), PIONA analysis (Paraffins, Isoparaffins, Olefins, Naphthenes, Aromatics)Describes analytical methods for determining hydrocarbon classes in fuels. Compares GC, simulated distillation, and PIONA analysis, highlighting principles, outputs, resolution limits, and how results guide blending decisions.
Gas chromatography principles and columnsSimulated distillation for boiling profilesPIONA methodology and class separationData interpretation for refinery blendingLimitations, calibration and quality controlLesson 7Other property correlations: flash point, viscosity, hydrogen content, and how molecular structure controls theseLinks molecular structure to flash point, viscosity, hydrogen content and related safety and performance properties. Shows how chain length, branching, and aromaticity shape handling, combustion quality and emissions.
Flash point trends with volatility and cutsViscosity versus chain length and shapeHydrogen to carbon ratio and emissionsLubricity, wear and molecular structureSpecification limits and property tradeoffsLesson 8Functional relationships: how chain length affects volatility, boiling point, and vapor pressureExplains how hydrocarbon chain length controls volatility, boiling point, and vapour pressure. Links intermolecular forces and surface area to phase behaviour, distillation curves, cold flow, and evaporation losses in fuels.
Intermolecular forces in hydrocarbon chainsBoiling point trends with carbon numberVapor pressure and volatility relationshipsImpact on distillation curves and cut pointsCold flow, evaporation loss and safetyLesson 9Aromatics: benzene, toluene, xylenes — structure, formation routes, distribution in crude fractions, role as petrochemical feedstocks and octane contributorsDetails aromatic hydrocarbons such as benzene, toluene and xylenes, their structures and formation routes. Reviews distribution across crude fractions, roles as octane boosters, and importance as petrochemical feedstocks.
Benzene, toluene and xylene ring structuresFormation in reforming and pyrolysis unitsDistribution in naphtha and heavier cutsOctane contribution in gasoline blendingPetrochemical and solvent applicationsLesson 10Branching vs straight chain: influence on octane number and volatility; use of Research Octane Number (RON) and Motor Octane Number (MON) conceptsAnalyses how branching versus straight chains affect octane number, volatility, and knock resistance. Explains RON and MON definitions, test conditions, sensitivity, and how fuel design balances drivability and efficiency.
Straight chains and low octane behaviorBranching patterns and octane enhancementVolatility changes with branching degreeDefinitions of RON, MON and sensitivityFuel design using RON and MON targetsLesson 11Rings and aromaticity: influence on density, energy content, soot tendency, and octane; effects on cetane number for dieselInvestigates ring systems and aromaticity, relating them to density, energy content, octane and soot tendency. Compares aromatics and naphthenes, and explains their contrasting effects on petrol octane and diesel cetane.
Aromaticity criteria and ring stabilizationDensity and volumetric energy relationshipsOctane enhancement by aromatics in gasolineSoot and particulate formation tendenciesEffects on diesel cetane and ignition delay
