The word “petroleum” means “rock oil” or “oil from the earth” (EIA, 2005).
Mankind has known petroleum or crude oil for the reason that dawn of civilisation. It was utilized in historical Persia and Burma, significantly as gasoline for lamps. Burning of the natural fuel (escaping from petroleum underground) gave the perpetual fire at Baba Gurgur in Iraq (Arene and Kitwood, 1979).
Makes use of OF PETROLEUM
Petroleum has two main uses. The first is as a gasoline. The combustion of crude oil gave in-street to derivation of assorted energies from petroleum. Petroleum has been a supply of power for heating, lighting and locomotion and significantly the most handy gasoline for the internal combustion engine. This use has increased quickly in significance with the coming of the motor automobile and a wide range of other purposes of inside combustion engine (Bankole and Ogunkoya, 1978).
The second use of petroleum is the synthesis of organic compounds. By 1965, about eighty% of the world organic chemicals have been synthesized from petroleum. This determine rose to 98% in 1980 and 99% within the year 2000. Thus, petroleum chemicals (petrochemicals) are a wide number of chemicals. Commercially important ones include gasoline and kerosine. Petroleum jelly is a greasy gelatinous substance sourced from petroleum and used as ointment base, lubricant and protecting masking (Arene and Kitwood, 1979).
THE ORIGIN OF PETROLEUM
Nelson (1954) wrote on two plausible schools of thought on the origin and formation of petroleum. The older one, “the natural matter concept”, means that petroleum was formed from the decomposition of useless marine organisms, like plankton. Compounds (e.g., fats) which are very much like hydrocarbons and even traces of certain hydrocarbons themselves, are present in nearly all forms of plant and animal life. The idea is supported by the discovering that very recent marine deposits (10,000 to 15,000 years previous) contain hydrocarbon and asphaltic material. Apart from, there’s a similarity between the molecular constructions of a few of the minor constituents of crude oil and people of compounds found in dwelling organisms. Once more, it is difficult to see where else the carbon content material of petroleum might have come from apart from biological materials, if indeed its origin is geologically fairly current.
Additionally, supporting this view, Arene and Kitwood (1979) submit that petroleum is crude oil that happens naturally in sedimentary rocks. It had collected into small pools from seepage from underground. Aligning with this declare, EIA (2005) states that petroleum was formed from the stays of animals and plants that lived tens of millions of years ago in a marine (water) environment before the dinosaurs. About 300-400 million years in the past, tiny sea plants and animals died and had been buried on the ocean floor. Over time, layers of silt and sand coated them. About 50-100 million years ago, the remains were buried deeper and deeper and coated by layers of mud. The big heat and strain from these layers turned the stays into crude oil and gas. At present, drilling down through the layers of silt, sand and rock assist to reach the rock formations that contain crude oil and gasoline deposits.
The challenge for the theory is accounting for the enormity of petroleum deposits. For such an unlimited amount of petroleum to be formed, the marine organisms would have to be ample over several million years. Another challenge is accounting for the accumulation of the oil in massive deposits. For this to happen, the dispersed droplets of crude oil must have migrated a very long distance. However, it’s doubtful whether or not a mechanism within the conditions and time-span favoured this.
The more recent faculty of thought, “atmospheric chemical reaction concept”, submits that petroleum could be very much older than the existence of life on the earth. The earth is over 5,000 million years previous and at the purpose when it was a hot molten mass, consisting primarily of Hydrogen (H) and Carbon Dioxide (CO2), chemical reactions between them formed an ideal vary of hydrocarbons which rose to the environment as vapour clouds much like those suspected to encompass the planet Venus at present:
As cooling of the earth proceeded, condensation led to a petroleum-rain that lasted 2,000 million years. Many valleys and basins collected the oil with its sediments. A lot latter, water-rain came, on which the oil floats.
The issue of accounting for huge measurement of the earths crude oil deposits is frequent to each theories.
PETROLEUM EXPLORATION AND Main PETROLEUM PRODUCING International locations
Arene and Kitwood (1979) be aware that crude oil is capable of flowing up the effectively pipe either under the strain current within the reservoir, or with mechanical assistance from a pump or applied stress. Since Drake, in Pennsylvania, United States of America (USA), drilled crude oil, the petroleum trade has steadily grown and numerous petroleum deposits have been discovered and drilled in varied parts of the world.
According to EIA (2005), scientists and engineers discover a chosen space by finding out rock samples from the earth. Measurements are taken and, if the location appears promising, drilling begins. Above the outlet, a construction called a ‘derrick’ is built to home the instruments and pipes going into the properly. When finished, the drilled properly will bring a gentle stream of oil to the floor.
The world’s prime five crude oil-producing international locations are Saudi Arabia, Russia, United States, Iran and China. Over one-fourth of the crude oil produced in the United States is produced offshore within the Gulf of Mexico. The highest crude oil-producing states are Texas, Alaska, California, Louisiana and New Mexico (NRC, 2003).
The quantity of crude oil produced within the United States has been getting smaller each year. Alternatively, the use of products made from crude oil has been growing, making it essential to deliver extra oil from other petroleum producing international locations. Thus, about fifty eight% of the crude oil and petroleum merchandise used within the United States come from other countries.
Based on the OPEC (2011), the Group of the Petroleum Exporting Countries (OPEC) was based in Baghdad, Iraq, with the signing of an agreement in September 1960 by five international locations, specifically Islamic Republic of Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. They were to turn out to be the Founder Members of the Organization.
Qatar (1961), Socialist Peoples Libyan Arab Jamahiriya (1962), the United Arab Emirates (1967), Algeria (1969), Nigeria (1971), Ecuador (1973) and Angola (2007) later joined these international locations.
From December 1992 until October 2007, Ecuador suspended its membership. Gabon terminated its membership in 1995. Indonesia suspended its membership efficient January 2009. Thus, presently, the Organization has a complete of 12 Member Countries: Islamic Republic of Iran, Iraq, Kuwait, Saudi Arabia, Venezuela, Qatar, Socialist Peoples Libyan Arab Jamahiriya, the United Arab Emirates, Algeria, Nigeria, Ecuador and Angola.
The OPEC Statute distinguishes between the Founder Members and Full Members – these nations whose purposes for membership have been accepted by the Conference. It stipulates that any nation with a substantial web export of crude petroleum which has fundamentally related interests to these of Member Nations, could become a Full Member of the Group, if accepted by a majority of three-fourths of Full Members, together with the concurring votes of all Founder Members. The Statute further offers for Associate Members who’re these nations that don’t qualify for full membership, however are nonetheless admitted below such special conditions as may be prescribed by the Conference.
The nature AND COMPOSITION OF PETROLEUM
Crude oil is a smelly, yellow-to-black liquid and is usually found in underground areas, referred to as reservoirs (EIA, 2005). Bankole and Ogunkoya ( 1978), Hobson (1973), Sweeney (1950), Sachanen (1945), McCain (1970) Shreve and Brink (1977) and Arene and Kitwood (1979) have observed that crude oil consists primarily of a mixture of gaseous, liquid and stable hydrocarbons. Some crude oils have sulphur-containing compounds, together with the thiol (mercaptans), comparable to ethanethiol (C2H5SH) and cyclic sulphides, such as the thiophen derivatives (e.g., tetrahydrothiophen and benzothiophen). Others additionally include natural nitrogen compounds. The nitrogen is often current in advanced ring structures, similar to carbazole:
Again, some crude oils include small quantities of natural acids, whose molecules have the carbonyl group (-COOH) (e.g., benzenecarboxylic acid). Besides, some crude oils contain traces of phenol-sort compounds, during which a hydroxyl group (-OH) is immediately connected to a benzene ring (e.g., phenol):
Shreve and Brink (1977), Nelson (1958), Rossini (1947), Sweeney (1950) and Arene and Kitwood (1979) have noted that petroleum is a extremely complex mixture, the primary constituents being compounds (gases, liquids and solid) of hydrocarbons (eleven-15% hydrogen and 83-87% carbon) that are classified as alkanes, cycloalkanes and aromatics. Crude oil is a viscous cell liquid combined with water and sand. Its appearance ranges from colourless to green-black. Crude oils fluctuate in density between 0.78 and 1.00 gcm-3.
Alkanes make up ninety% of most crude oils. They are compounds of hydrogen and carbon only. Some alkanes have straight chain, e.g., pentane (Arene and Kitwood, 1979):
Others have branched chains, e.g., 2,2,4-trimethylpentane (iso-octane) (Arene and Kitwood, 1979):
Straight-chain alkanes are undesirable in petrol, but desirable in kerosines and diesel fuels. Also, the straight-chain alkanes are most well-liked for the manufacture of detergents and for the bacteriological manufacturing of protein (Eneh, 2000a).
Cycloalkanes are ring-structure hydrocarbons with single bonding solely, e.g., cyclopentane, cyclohexane, and so on:
Aromatics have molecules containing the ring construction characteristic of benzene, e.g. benzene, ethylbenzene, 1,2-dimethylbenzene, naphthalene and biphenyl (Arene and Kitwood, 1979):
PETROLEUM PROCESSING AND Merchandise
In accordance with Sharma (2002), Bankole and Ogunkoya (1978), Hobson (1973), McCain (1970), Kimberlin (1957), Rossini and Mair (1951), Shreve and Brink (1977), Arene and Kitwood (1979), Eneh (2007, 2000a, b), USDE (1999) and Saepudin et al. (2010), the process of getting helpful merchandise from crude oil is named refining. After crude oil is removed from the bottom, it is shipped by pipeline, ship or barge to a refinery, where totally different components of the crude oil are separated into useable petroleum products.
Both kerosine and petrol had been obtained from petroleum by fractional distillation. With growing demand for more efficient products than the products of crude oil distillation, numerous strategies have been developed for changing the primary distillation merchandise into helpful chemicals.
Filtration separates sand and other solid issues from the crude oil which is allowed to face in reservoir for the more dense water to form a decrease layer from the oil layer above. The latter is pumped via pipelines to the refinery, where continuous distillation or fractionation separates the crude oil into various cuts or fractions of different boiling ranges. Table 1 contains products from a typical fractionation.
The boiling points of merchandise from petroleum refining range from 20 to above 400°C. The boiling range is said to the number of carbon atoms of the compound and is related to the character-fuel or liquid-and use of the product. For example, compounds with C5-C10 have boiling vary of 20-160°C and are largely liquids.
The proportions of every fraction obtained differ each with the type of crude oil and the distillation process. For instance, the yields of the most useful fractions from Nigerias refinery are approximately petrol (10%), kerosine (20%) and gasoline (30%). There’s demand for Nigerias crude oil due to its low sulphur content material (zero.14%), as against others. As an example, the crude oil from Persian Golf incorporates about 7% sulphur. Petroleum was found in Nigeria in Oloibiri city in the current Bayelsa State in 1956 and industrial manufacturing started in 1957, rising steadily since then (Schatze, 1970; Arene and Kitwood, 1979).
Crude oil is measured in Barrels (bbls). A 42-U.S. gallon bbl of crude oil gives barely more than 44 gallons of petroleum merchandise. One barrel of crude oil, when refined, produces about 20 gallons of completed motor gasoline (19.6%), 7 gallons of diesel (10%), jet gas (four%), heavy fuel oil (1.7%), liquefied petroleum fuel, LPG (1.7%), as well as different petroleum products (7.6%). The gain from processing is about 5%. Many of the petroleum merchandise are used to supply power. As an example, many individuals across the United States use propane to heat their properties and gasoline their vehicles. Different products made from petroleum embody: ink, crayons, bubble gum, dishwashing liquids, deodorant, eyeglasses, data, tires, ammonia and heat valves (USDE, 1999).
Thus, primary distillation of crude oil yields petrol which is small relative to demand and yields way more of the upper-boiling constituents than required. Cracking is the method devised for conversion of the big hydrocarbon molecules into smaller ones. The previous thermal cracking used 300-700oC temperatures and pressures up to 30 atmospheres. In keeping with Arene and Kitwood (1979), it has been largely changed by catalytic cracking, using catalyst (e.g. silicon IV oxide, aluminium III oxide), about 500oC temperature and about atmospheric strain.
Catalytic cracking is simpler to control and yields particular kinds of merchandise. The first cracking process breaks alkane into alkene molecule (with carbon-carbon double bond, C = C) and a small alkane molecule:
The ensuing alkene is so reactive that it might probably undergo isomerisation (altering its construction). It may bear polymerisation (joining together to type bigger unit). In each processes it yields not solely hydrocarbons appropriate for petrol, kerosine and diesel however a number of gases (butane and butene, 45%; propane and propene, 3%; ethane and ethene, 15%; methane 10%; and just a little hydrogen). These are vital as raw materials for the petrochemical industry. Typically, the full gas yield is 15-20% of the cost.
Hydrocracking is a catalytic cracking process designed to increase the yield of the petrol by supplying hydrogen to boost the formation of lower alkanes at excessive pressures (one hundred fifty-200 atmospheres) and average temperatures (400-450°C). The catalysts could also be aluminosilicate materials or cation of palladium and nickel. The merchandise from Hydrocracking are largely alkanes, unlike those from easy cracking which contain alkenes also. Reforming is a process of alteration of the molecular construction of the hydrocarbons in the decrease fractions obtained from major distillation or from cracking. The yields are branched-chain hydrocarbons within the C6 to C10 range that are needed for top-grade motor gas. The feed typically consists of fabric boiling up to about 200oC. The simplest catalyst consists of platinum (about 0.5% by weight) on highly purified aluminium (III) oxide. Three sorts of reaction typical of reforming are:
Aromatisation or formation of an aromatic (benzene-type) compound from a cycloalkane, e.g.:
Dehydrocyclisation or formation of a compound with a ring construction from one with a straight chain, followed by lack of hydrogen, e.g.:
Isomerisation or rearrangement, without net lack of any constituent, e.g.:
According to Sharma (2002) and Arene and Kitwood (1979), a poor high quality fuel tends to knock or explode unevenly and prematurely, particularly in a excessive-compression engine. 2,2,four-Trimethylpentane (wrongly known as iso-octane) is an effective fuel, as a result of it burns easily and doesn’t trigger knocking. It’s, due to this fact, assigned the arbitrary octane number of a hundred (on a zero-to-a hundred scale). On the other hand, heptane is a nasty gas, as a result of it is particularly inclined to causing knocking. It is, due to this fact, assigned the octane variety of zero. The octane quantity or octane score of petrol is, subsequently, the percentage of iso-octane blended with heptane which displays the knocking traits of the gasoline. It’s a measure of its efficiency in an inside-combustion engine.
The quality of the fuel will be improved (or the octane number or octane rating of the gasoline may be raised) by addition of branched-chain hydrocarbons or aromatic compounds. Ethanol and methanol are added to some fuels to improve their efficiency. Additionally, tetraethyl-lead (IV), Pb(C2H5)4, added in small proportions, greatly will increase the octane number of a fuel; 0.03% by weight might raise the octane quantity by 15-20 units. Nevertheless, this practice has been discouraged and outlawed in most international locations because of environmental pollution and lead-poisoning that outcome from the usage of such fuels (Kymisis and Hadjistavrou, 2008; Goss et al., 2004; Kim and AAPCEH, 2004).
THE PETROCHEMICAL Business
In line with Bankole and Ogunkoya (1978), Tedder et al. (1979), Waddams (1973), Shreve and Brink (1977) and Kimberlin (1957), the production of chemicals from petroleum has elevated enormously since World Warfare II.
Even, inorganic chemicals have been produced from petrochemical, e.g., carbon black from methane. Table 2 lists some chemicals produced from petrochemicals.
For example, methane, ethyne and synthesis fuel are petrochemicals from which other chemicals are produced. From methane, carbon black, ethyne, synthesis gasoline, halogenmethanes and hydrogen cyanide are produced. From ethyne, chloroethene compounds and ethanal are produced. And, from synthesis fuel, methanol and ammonia are produced.
PETROLEUM AND THE Surroundings
Regardless that petroleum products make life simpler by their use in fueling airplanes, cars, trucks, cooking stoves and other purposes in combustion engines, in addition to in heating our houses, utilizing them may cause environmental issues, like air and water pollution. When petroleum products are burned as fuel, they give off carbon dioxide (CO2), a greenhouse gasoline that’s linked with global warming. The use of petroleum merchandise additionally provides off pollutants-Carbon monoxide (CO), nitrogen oxides, particulate matter and unburned hydrocarbons-that pollute the air humans breathe. Since numerous air pollution comes from vehicles and trucks, many environmental laws have been aimed toward altering the make-up of gasoline and diesel gasoline so that they produce fewer emissions. These “reformulated fuels” are much cleaner burning than gasoline and diesel fuel was in 1990. In the subsequent few years, the quantity of sulphur contained in gasoline and diesel gasoline will probably be diminished dramatically in order that they can be utilized with new, less-polluting once more expertise (USDE, 1999).
Exploring and drilling for oil could disturb land and ocean habitats. A study on evaluation of the affect of oil exploration activities on agriculture and pure assets within the Niger Delta Area of Nigeria showed that oil exploration actions adversely impacted particularly on soil/land sources, aquatic life/fisheries, water assets, crops, livestock and forests/vegetation. Oil spills have degraded most agricultural lands, reduced the availability of fish and fish products, induced the pollution of floor and floor water resources, destruction of arable and tree crops and loss of life of farm animals in the region on account of toxic materials in the soil and polluted water. Oil exploration activities have also resulted within the disappearance of some forest vegetation and animal species, together with primates, fish, turtles and birds. The final word outcome of those impacts is a drastic reduction in farm productivity and animal farm earnings (Ugwu, 2009; Eneh, 2011a, b; Tabieh and Al-Horani, 2010; Al-Turki, 2010).
New technologies have enormously diminished the quantity and dimension of areas disturbed by drilling, sometimes called “footprints.” Satellites, global positioning methods, remote sensing gadgets and 3-D and 4-D seismic applied sciences, make it possible to find oil reserves while drilling fewer wells. Again, the usage of horizontal and directional drilling makes it doable for a single well to provide oil from much larger areas. Right this moment’s production footprints are only about one-fourth the scale of these of 30 years in the past, as a result of the development of movable drilling rigs and smaller “slimhole” drilling rigs. When the oil in a well is gone, the well have to be plugged beneath floor, although its soil fertility is gone. As part of the “rig-to-reefs” programme, some previous offshore rigs are toppled and left on the sea floor to change into artificial reefs that appeal to fish and different marine life. Inside six months to a year after a rig is toppled, it turns into coated with barnacles, coral, sponges, clams and different sea creatures (USDE, 1999).
If oil is spilled into rivers or oceans it will possibly hurt wildlife. Oil spills can come from natural oil seeps from the ocean floor, ships that crash, or leaks that occur when petroleum products are used on land, such as the gasoline that generally drips onto the bottom when people are filling their fuel tanks, motor oil that will get thrown away after an oil change, or fuel that escapes from a leaky storage tank. When it rains, the spilled products get washed into the gutter and eventually go to rivers and the ocean. Another method that oil typically gets into water is when fuel is leaked from motorboats and jet skis (USDE, 1999).
When a leak in a storage tank or pipeline occurs, petroleum merchandise may also get into the ground. In some places where gasoline has leaked from storage tanks, one of many gasoline ingredients, referred to as Methyl Tertiary Butyl Ether (MTBE), has made its method into native water supplies. Since MTBE makes water taste bad and plenty of people are nervous about drinking it, plenty of states are banning using MTBE in gasoline and the refining business is voluntarily transferring away from utilizing it when mixing reformulated gasoline. To stop leaks from underground storage tanks, all buried tanks are alleged to be changed by tanks with a double lining (USDE, 1999).
The overview has tried to marry dated and current literature on petroleum. It has introduced out clearly the that means of petroleum from the Medieval Latin phrases, petra and oleum; the makes use of of petroleum, the 2 plausible theories on the origin and formation of petroleum; petroleum exploration and the foremost petroleum producing nations on the planet, together with the member states of the Organisation of the Petroleum Exporting Countries, OPEC; the character and composition of petroleum; petroleum processing and products; octane quantity or score, the petrochemical industry; and petroleum and the surroundings.