Alkanes (Paraffins)

Alkanes are saturated hydrocarbons having the general formula C_nH_2n+2. The simplest alkane, methane (CH₄), is the principal constituent of natural gas. Methane, ethane, propane, and butane are gaseous hydrocarbons at ambient temperatures and atmospheric pressure. They are usually found associated with crude oils in a dissolved state.  Normal alkanes (n-alkanes, n-paraffins) are straight-chain hydrocarbons having no branches. Branched alkanes are saturated hydrocarbons with an alkyl substituent or a side branch from the main chain. Abranched alkane with the same number of carbons and hydrogens as an n-alkane is called an isomer. For example, butane (C₄H₁₀) has two isomers, n-butane and 2-methyl propane (isobutane). As the molecular weight of the hydrocarbon increases, the number of isomers also increases. Pentane (C₅C₁₂)  has three isomers; hexane (C₆H₁₄) has five. The following shows the An isoparaffin is an isomer having a methyl group branching from carbon number 2 of the main chain.

A naphtha fraction  (obtained as a light liquid stream from crude fractionation) with a narrow boiling range may contain a limited but still large number of isomers.

مواضيع ذات صلة

سلوك المعادن الطينية في علاقتها مع الماء

تصنيف النفط الخام Classification of Crude Oils

التحليل المطلق Ultimate Analysis

المكونات الرئيسية للنفط الخام الموجود في منطقة القيارة

نفط خام القيار

النفط الخام ومكوناته

النفط والطاقة Oil and Energy

مزائج اسفلت – اسفلتين

أساليب تحوير المواصفات الريولوجية للاسفلت

صفات الاسفلت الريولوجية Properties of Asphalt Rheological

استخدامات الاسفلت Asphalt Uses of

التركيب الكيميائي للاسفلت Chemical Composition of Asphalt