Hydrocarbon

// Hydrocarbons

• Alkanes (paraffins)
  • Saturated HC
  • Classified into 3 categories;
    • Straight chain HC
    • Branched alkanes – with alkyl substituent
    • isoparaffin – methyl group branching from carbon no 2

• Cycloparaffins
  • Saturated cyclic HC
  • E.g. cyclopentane, cyclohexane
  • Normally present in light naphtha and heavy naphtha
  • Important precursors for aromatic HC :
    • cyclohexane
    • substituted cyclopentane
    • sustituted cyclohexane

• Note: Naphthenic compounds are sometimes called naphthenes, cycloparaffins or hydrogenated benzenes. Naphtha is a refined petrokeum fraction that contains a high percentage of these types of hydrocarbons

• Aromatic compound
  • Lower members of aromatic compounds are present in small amounts in crude oils and light petroleum fractions.
  • The simplest mononuclear aromatic compound is benzene (C₆H₆).
  • Toluene (C₇H₈) and xylene (C₈H₁₀) are also mononuclear aromatic compounds found in variable amounts in crude oils.
  • Benzene, toluene, and xylenes (BTX) are important petrochemical intermediates as well as valuable gasoline components.
  • Separating BTX aromatics from crude oil distillates is not feasible because they are present in low concentrations. Enriching a naphtha fraction with these aromatics is possible through a catalytic reforming process.