Fundamentals of Petroleum Refining
Compositions of Crude Oils
Lecturers:
assistant teachers
Kirgina Maria Vladimirovna
Belinskaya Natalia Sergeevna
1
Fundamentals of Petroleum Refining. Crude oils Composition
Introduction
 Crude oil comes from different parts of the world and has different
Название темы
physical and chemical characteristics.
 The products that are produced have to meet market requirements and
as such, should comply with certain specifications.
2
Fundamentals of Petroleum Refining. Crude oils Composition
Elemental composition of Crude oils
Crude oil is a complex liquid mixture made up of a vast number of
Название темы
hydrocarbon
compounds
Element
Composition (wt %)
Carbon
83.0 – 87.0
Hydrogen
10.0 – 14.0
Sulphur
0.05 – 6.0
Nitrogen
0.1 – 0.2
Oxygen
0.05 – 2.0
Ni
< 120 ppm
V
< 1200 ppm
3
Fundamentals of Petroleum Refining. Crude oils Composition
Classes of hydrocarbons
 Saturated hydrocarbons contain only carbon–carbon single bonds.
Название темы
- paraffins (alkanes)
- naphthenes (cycloalkanes)
 Unsaturated hydrocarbons (olefins) contain carbon–carbon multiple
bonds (double, triple or both). They contain fewer hydrogens per carbon
than paraffins
- alkenes contain a carbon–carbon double bond
- alkynes contain carbon–carbon triple bond
 Aromatic hydrocarbons are special class of cyclic compounds related
in structure to benzene
4
Fundamentals of Petroleum Refining. Crude oils Composition
Paraffins (alkanes)
 General formula is CnH2n+2
- n is the number of carbon Название
atoms темы
 Normal paraffins (n-paraffins or n-alkanes) are unbranched
straightchain molecule
 Isoparaffins (or isoalkanes) are branched-type hydrocarbons that
exhibit structural isomerization
5
Fundamentals of Petroleum Refining. Crude oils Composition
Olefins (alkenes)
 unsaturated hydrocarbons containing carbon–carbon double bonds
Название темы
 acetylenes (alkynes) are compounds containing carbon–carbon triple
bonds
 the general formula of olefins is CnH2n(R–CH=CH–R’)
 the general formula of acetylenes is CnH2n–2(R–CH≡C–R’)
 alkadienes (dienes) are compounds containing two double bonds
(R–CH=CH–CH=R’)
6
Fundamentals of Petroleum Refining. Crude oils Composition
Naphthenes (cycloalkanes)
 saturated hydrocarbons that have at least one ring of carbon atoms
Название темы
 The boiling point and densities of naphthenes are higher than those of
alkanes having the same number of carbon atoms
7
Fundamentals of Petroleum Refining. Crude oils Composition
Aromatics
 unsaturated cyclic compounds composed of one or more benzene rings
Название темы
 the benzene ring has three double bonds with unique electron
arrangements that make it quite stable
 polynuclear aromatic compounds
8