Petroleum is a complex non-homogeneous mixture of hydrocarbons, composed / formed of hydrogen and carbon. It is a non-renewable natural resource, the raw material for many materials and products, and, as a fossil fuel, the main primary energy source in the world.
The different existing types differ greatly from each other, they can be from yellowish and liquid to black and viscous. These differences are due to the relationships between the types of hydrocarbons.
This mixture of hydrocarbons appears generally associated with large deposits of natural gas, in fields closed for thousands of years underground, covered by the upper layers of the Earth's crust.
Oil is a fossil fuel widely used to obtain fossil energy. Fossil energy refers to obtaining energy using fossil fuel. Its main derivatives (diesel or gasoline) are widely used in heat engines and other industrial machines.
What is the origin of the petroleum?
Oil originates from shallow marine basins where large amounts of plankton proliferate . When the plankton dies it accumulates along with a large amount of organic matter that remains in the mud at the bottom of the sedimentary basin.
If these organisms are too long on the seabed, they will undergo an oxidation process .
Also, if they are out of contact with the oxygen dissolved in the seawater when buried by an impermeable inorganic sediment, they will undergo a diagenetic process under anaerobic conditions, where the increase in pressure and temperature participate, along with the action of anaerobic bacteria that transform organic matter in hydrocarbons.
In a first phase , the compaction and lithification of the sediment take place at the same time : the bacteria break down the living organisms with which they feed, and transform the residues into an insoluble organic substance with cyclic structures that is called cherogen and constitutes the petroleum raw material.
Petroleum is produced by the transformation of the fatty acids of the kerogen which are transformed into heavy hydrocarbons and which, after a maturation process, break down and originate liquid and gaseous hydrocarbons.
Once the hydrocarbons are formed inside the sediment, two things can happen in their transformation:
- That the hydrocarbon stays inside the rock where it formed , which is normally impermeable and with a fine texture. These rocks are called bituminous shales, and their commercial exploitation is not very profitable, since it is necessary to carry out processes of excavation, crushing and distillation of large quantities of rocks until liquid oil can be obtained. These are processes that require a large amount of water and generate a large amount of rocky waste (great ecological impact).
- Oil migration . If the rock has been buried deep, it is very possible that the fossil fuel will escape to higher areas to another material with greater porosity and permeability, due to the strong compaction.
The oil is not found in a certain type of rock but it permeates any rock that is sufficiently porous (with holes in it). In addition to oil, methane and salt water are also found in these rocks, from their formation process.
What are petroleum derivatives?
Petroleum products are materials produced from the crude element . This is generally done at oil refineries. Unlike distillates , which are precisely defined pure compounds, derived products are complex mixtures. Most of the hydrocarbon is converted to by-products that include various kinds of fuel.
Depending on the composition of crude oil and market demand, refineries can produce a variety of derived products. Most derived products are used as "energy carriers", for example various types of fuel oil and gasoline . These fuels include or can be mixed to produce kerosene, diesel, and other heavy fuels.
The heavier (less volatile ) particles can also be used to produce asphalt , tar , paraffin , lubricants, and other heavy oils.
Refineries also produce other chemicals. A ome of which are used in chemical processes to yield plastics and other useful materials.
Because petroleum often contains various percentages of sulfur- containing molecules , the latter is often produced as a by-product. Carbon , as coke of oil , and hydrogen can also be produced as byproducts.
The hydrogen produced is often used as an intermediate for other refinery processes, such as cracking and hydrodesulfurization .
A refinery is an industrial plant where crude oil is converted and refined into more useful products such as gasoline, diesel, asphalt, kerosene, propane-butane, fuel oil, and lubricants.
Refineries are typically large industrial complexes with numerous pipelines that transport fluid flows between large aggregates for chemical processes. These plants use numerous technologies and are considered chemical plants. They often have auxiliary facilities and storage tanks.
Each refinery has its own arrangement of refining processes, primarily determined by the location of the plant, the products produced, and economic considerations.
What are petroleum products?
The main derived products are:
- Gas fuels such as propane, liquid stored and transported and pressurized in specialized trains to distributors.
- Mixed liquid fuels (gasoline, kerosene, diesel, paints, cleaning products). They are transported by barge, train, or tank truck. They can be transported regionally through special pipelines, especially jet fuel to major airports.
- The lubricants (oils lightweight machine, motor oils, grease, adding viscosity stabilizers) are generally shipped together packaging companies.
- Paraffin used in frozen food packaging. They can be shipped together to packaging companies.
- Raw wax consisting of a mixture of oil and wax used as a paraffin precursor, candles, oxide coatings, and vapor barriers.
- The sulfur , a byproduct of the removal of sulfur from petroleum, contains a percentage of organo-sulfur compounds.
- Tar , for transportation to masonry companies and for use on roofs.
- The asphalt used as a binder for the gravel in the formation of asphalt, which is used in road and other surfaces.
- Petroleum coke used in some carbon products, such as electrodes or solid fuels.
- Distillates and raw materials for the production of polymers and pharmaceutical products. Examples are ethylene and benzene-toluene-xylene.
What environmental effects does oil cause?
Among the most serious environmental disasters that threaten biodiversity are oil spills in rivers, seas and oceans.
Oil damages marine ecosystems producing one or more of the following effects:
- Death of organisms by suffocation.
- Destruction of young or newborn organisms.
- Decreased resistance or increased infections in species, especially birds, by absorption of certain sub-lethal amounts of oil.
- Negative effects on reproduction and spread to marine fauna and flora.
- Destruction of food sources of higher species.
- Incorporation of carcinogens in the food chain. The truth is that whatever the way pollution occurs, in the long term the entire ecosystem is affected, and it is even claimed that it can reach man through the food chain.
Effects on human health
Oil or its components can come into contact with the human body through three routes:
- absorption by the skin
- ingesting food and drink
- inhalation through breathing.
The effects on man of acute exposure to crude oil are primarily transient and short-lived unless concentrations of the compounds are unusually high. Such exposures cause:
- Skin irritation
- Eye irritation upon accidental contact or exposure to its vapors
- Possibility of causing nausea, vertigo, headaches or dizziness in prolonged or repeated exposure to low concentrations of its volatile compounds.
Inhaling mineral oils can lead to lipoid pneumonia and death.
High benzene concentrations cause neurotoxic symptoms, and prolonged exposure to toxic levels can cause bone marrow injury with persistent pancytopenia. Benzene is also a well-known cause of leukemia and probably of other hematologic tumors.
Atmospheric effects and greenhouse gases
One of the main applications of oil is the manufacture of fossil fuels.
There are multiple applications, especially in the industry and the automotive sector, in which fossil fuel is burned to obtain thermal energy.
The burning of fossil fuels generates a large amount of greenhouse gases that contribute to worsening the planet's climate change. Furthermore, they can cause respiratory problems in humans and animals.