PETROLEUM AS THE PRODUCT OF ORGANIC CHEMISTRY

Petroleum is defined as any mixture of hydrocarbons that can be recovered from a drill pipe. It occurs in form of oil and gas which mainly have a chemical composition of hydrocarbons of various carbon chains.

Origin

By referring to different grounds from two opposing theoretical hypothesis, petroleum origin and formation still become a polarized topic of scientists’ debates. These theories are abiogenesis and biogenesis. Abiogenesis-inorganic origin of petroleum, is an oldest theory which suggests that petroleum comes from the underneath part of the mantle very long time ago before the existence of life on earth (Mendeleev, 1877). 

Dmitry Mendeleev

The second hypothesis, biotic or organic origin suggests that petroleum is formed from biological matters, left behind by very ancient lives. These matters become subjected to high temperature under the absence of oxygen. 

The last hypothesis, biogenesis is currently accepted by many people due to how it is supported by various valid grounds while the first one is more doubtful. Its early supportive tenets lost their truth, especially when they fall in contraction with modern science.

History

Early in 16th century, a theory of the origin of oil stated that it resulted from very deep carbon deposits that have been around far longer than life on this planet. 

That theory, lately became known as the abiotic oil formation (AOF) theory, was largely [ignored] and forgotten until rather recently when a few people-some of them scientists revived it and backed  it with some tenets .

Ancient Abiotic Oil Formation

The idea concerning the origin of petroleum dates back to the 18th and early part of the 19th century, when the chemical nature of petroleum was not known.

Different perspective of petroleum

Biotic origin of petroleum inspires the possibility of exhausting oil reserves and abiotic hypothesis assure quasi-unlimited supplies of oil and gas reserves. Therefore many issues regarding energy renewability rises. 

Politics as the main driver of every issue in our modern socio-economic aspects of living, the arguments of abiotic versus biotic origins of petroleum are caused by some hidden reasons which are for particular interests and politically motivated. For example, “a limited supply can be used to control people and as justification for actions like war. 

An unlimited supply, on the other hand, means that we need not worry about running out, that we ought to be able to drill for more oil and increase the daily supply so as to decrease price, and so forth”

Chemical Composition of Petroleum

Petroleum or crude oil is a complex mixture of hydrocarbons and other chemicals. The composition varies widely depending where and how the petroleum was formed. In fact, a chemical analysis can be used to fingerprint the source of the petroleum. However, raw petroleum or crude oil has characteristic properties and composition.

paraffins (15-60%)

naphthenes (30-60%)

aromatics (3-30%)

asphaltics (remainder)

The hydrocarbons primarily are alkanes, cycloalkanes and aromatic hydrocarbons.

Elemental Composition of Petroleum

Although there is considerable variation between the ratios of organic molecules, the elemental composition of petroleum is well-defined:

1. Carbon - 83 to 87%

1. Hydrogen - 10 to 14%

1. Nitrogen - 0.1 to 2%

1. Oxygen - 0.05 to 1.5%

1. Sulfur - 0.05 to 6.0%

1. Metals - < 0.1%

The most common metals are iron, nickel, copper and vanadium.

Conclusion

Biotic origin of petroleum fits today science with plausible evidences and it is commonly accepted as the true hypothesis to explain the origin of petroleum regardless of some few confrontations with its counterpart.