Petroleum (L. petroleum, from Greek: petra (rock) + Latin: oleum (oil)) or crude
oil is a naturally occurring, flammable liquid consisting of a complex mixture
of hydrocarbons of various molecular weights and
other liquid organic
compounds, that are
found in geologic
formations beneath
the Earth's surface. Petroleum is recovered
mostly through oil
drilling. This latter
stage comes after the studies of structural geology (at the reservoir scale),
sedimentary basin analysis, reservoir characterization (mainly in terms of
porosity and permeable structures). It is refined and separated, most
easily by boiling
point, into a large
number of consumer products, from petrol and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals. Petroleum is used in
manufacturing a wide variety of materials.
FORMED AND EXPLORATION
The crude oil
we use today was formed millions of years ago. Oil is formed deep under the
surface. Petroleum is formed from organic materials. This organic material
comes from the remains of dead organisms. The organic material becomes a part
of layers of sedimentary rocks. More layers form on the top of these layers and
the organic material changes into petroleum, and is contained into a source
rock. This causes the petroleum to turn into oil.
petroleum are
often found on the seabed near the loose beach
so constructed offshore oil platforms and the mainland not
far from the beach. This is due the movement of the earth's
crust that cause a shift in the lining rocks, such as
earthquakes and volcanic eruptions. There are illustration of how the
ptroleum formed.
To
determine the source of the petroleum needed knowledge
geology and experience. This work is
a duty and responsibility
responsible mining and geological engineers.
The first
stage of oil exploration is to find clues in the
earth's surface like the folds of rock. The folds
was due to pressure oil and gas that seeps into
the rocks porous so that oil can rise to the
surface, but not reaching the earth's surface because it
was blocked by layers of other rocks. Based
on observations and surface structure clues earth, the
next area investigated using the beam wave
seismic. The radiation of seismic waves are
used to determine rock structures in the skin layer of the
earth.
Seismic waves are
created using a small explosion. Explosion This will generate a
wave and sends it to the depth certain. If there
is a bubbling rock structures (anti Cline), wave will
be reflected back. These reflections can be
detected by sensor so that it can be seen to
accurately position the petroleum To remove the oil
and natural gas from rock layers layer
of earth drilling required to reach the
bottom layer of rock containing petroleum. Depth can reach hundreds
of meters. Once drilled, the oil initially will
radiateits own due layers of earth pressure is high, but the
more upward pressure is increasing weak so that the required pressure from the
outside. This is done by using water or air pump until oil can
pumped out. Transportation of crude oil can be done
with using tankers.
COMPOSITION OF CRUDE OIL
Crude
oil is a very complex mixture, which is
about 50-95% are hydrocarbons, especially
the alkanes with molecular weight above
100's; cycloalkanes; aromatic compounds; Compound micro, such
as organic acids, and inorganic elements such
as sulfur. Hydrocarbons in crude oil consists
of saturated hydrocarbons, aliphatic, and alicyclic. Most
of the components of crude oil is
saturated hydrocarbons, ie alkanes and cycloalkanes.
1. Alkane
Alkane compounds contained
in any oil that has a chain carbon straight as n-butane
and n heptane, there also have carbon chain branch such
as 2,2,4 trimetilpentan (isooktana). Alkane compound structural
formula is:
In the petroleum compounds are most
commonly found compounds straight chain hydrocarbons.
2.Cycloalkanes
Cycloalkanes are
found in petroleum for example metilsiklopentana and etilsikloheksana
with the following structural formula is:
3. Aromatic hydrocarbons
The
simplest aromatic hydrocarbon compounds found in petroleum is benzene
(C6H6) and metilbenzena with the structural formula
is:
4. Other compounds
Composition of petroleum out
varies from area to area. There are saturated hydrocarbons, unsaturated hydrocarbons, sulfur and oxygen compounds, and organ
metallic. The number of content or levels of these
compounds to determine the quality of petroleum. The
results of refining the oil
and gas in Indonesia has better quality than those produced byother
countries.
PROCES TO MAKE PETROLEUM CAN BE USES
Crude oil is a very complex
mixture of the need to be further processed to be used.
1. Distillation
Crude oil needs
to be processed in refineries through
stratified by fractionating distillation techniques. The
basic principle of distillation boiling point rise is
the difference in between crude oil fractions.
Hydrocarbons which has the lowest boiling
point will separate first, followed by a hydrocarbon having a
boiling point over high. So, gradually, hydrocarbons can be
separated from mixture of crude oil.
The
first fraction of crude oil out of the refinery is
hydrocarbon compounds with low
molecular mass, less than 70 sma.
This fraction is packaged in a pressurized tube until melted. Outcome
processing in this fraction is known as LPG (liquid
petroleum gas). After all factions teruapkan, which came
out the next fraction is
gasoline fraction. Temperature is applied to
remove this fraction ranged between 40 -200 ° C.
At these
temperatures, hydrocarbons ranging from pentane to octane
removed from the distillation (see the boiling point
of pentane to octane).
At room
temperature, form of this fraction was a colorless
liquid until slightly yellow and volatile. And so
on until all the fractions can be separated incrementally based
on differences in their boiling points. The results
of the fractionation leaving
a residue called black-colored asphalt.
2. Cracking
2. Cracking
To
meet the needs of a particular product, hydrocarbon long-chain can
be broken down into shorter through the process cracking (cracking). Conversely, short
chain hydrocarbons can be combined into a longer
chain (reforming). To increase the gasoline fraction can
be done in a way break down long chain hydrocarbons into fractions (C5-C9) through
thermal cracking. Cracking process is carried out at a
temperature of 500 ° C. and a pressure of 25 atm. Saturated straightchain hydrocarbons
such as kerosene (C12H26) can be crack into two shorter fragments there
are hexane (C6H14) and hexene (C6H12).
The presence of hexene (alkenes) from the thermal cracking can
be increase the octane number of 10 units. However,
the product of the process This cracking is generally
less stable when stored for a long time. Therefore the
thermal cracking products are generally less stable then the thermal cracking technique is
replaced by catalytic cracking conducted using a catalyst at high
temperature and pressure.
Catalytic cracking,
for example long-chain alkanes is reacted with mixture
of silicon (SiO2) and alumina (Al2O3), plus
a hydrogen gas or a specific catalyst.
In reforming, small molecules are combined into molecules is greater. This is done to improve petrol products. For example, butane and propane are reacted to form heptane. Reaction equation:
In reforming, small molecules are combined into molecules is greater. This is done to improve petrol products. For example, butane and propane are reacted to form heptane. Reaction equation:
3. Reforming
Small molecules are
combined into greater molecules. This is done to improve
petrol products, change shape/structure of gasoline’s molecule from bad quality (straight carbon chain) to good quality (branch carbon chain). For example, butane and propane are reacted to form heptane. Reaction equation:
petrol products, change shape/structure of gasoline’s molecule from bad quality (straight carbon chain) to good quality (branch carbon chain). For example, butane and propane are reacted to form heptane. Reaction equation:
4. Octane
number
Octane number
is the number ratio of value gasoline knock and value hydrocarbon mixture
standar knock The function is for distrution burning of gasoline to avoid
knocking a result of the shock wave when burning gasoline straight chain are
uneven in high pressure engine.
Three methode
for measure octane number:
1) measurements
at velocity and high
temperatures, the results are expressed as the engine
octane numbers;
2) measurements
on medium speed, the result is called the
research octane number;
3) pure hydrocarbon measurement,
called octane numbers road index.
Because 2,2,4trimetilpentana
has the highest octane number
(100) and n-heptane lowest(0) then the mixture of two compounds used
as standards to measure the octane number. Octane
number for mixture of 87% isooktana and 13%
n-heptane is set at 87 units.
ANOTHER PRODUCT FROM PETROLEUM
ENVIROMENT IMPACT
1. Hydrocarbon
(CnHx)
It
is formed by the impaired combustion that cause global warming. Some
hydrocarbon is stink dan the other role in photochemical. Some aromatics and
its derivative causes cancer, while olefins in high concentration
can inhibit plant growth. In the air, hydrocarbon make the ozon
concentration increase, form the organic compound likes peroxyacetyl nitrate
(PAN), peroxybenzoil nitrate (PBzN) and nitric acid. That compound together
then form fog called photochemical fog (causes the fog formed from photochemial
reaction).
2. Carbon
monoxide
It is caused by the impaired combustion of
gasoline. It is toxic so that causes headache. if in the air contain much CO
gas, hemoglobin will bind CO gas than O2
gas. So people who breath the gas continued will be die.
The symptomps of
being poisened by CO:
Step 1: sick
headache and weak.
Step 2: hard to
breath, heart attack, dan collaps.
Step
3: death and lips look pale.
3. Nitrogenoxide
It
can causes acid rain and effect the engine to heat-up quickly.
4. Soft
lead particles
soft lead particles come from incomplate combustion in vehicle engine. It
causes brain damage, especially for kids.
5. Smoke
It
is formed by carbon particles which are not burned. These particles can cause
lungs inflammation.
6. Sulphuric
oxide
SO2
derived cause of gasoline still contain sulfur, it can form be SO3. in dampness
its very corosive. Over 0.20 ppm for 24 hours in the air its causes
respiratory system disorders, cancer and acute bronchitis. That occur
becase SO2 breathed react with water in respiratory sistem form sulfit acid.
The reaction is:
7. Greenhouse Effect
When
the fossil fuels burned in cars and a power, CO2 gas is
released as residual gas is removed. Actually there
is a gas naturally in the earth's atmosphere to trap solar
heat that the earth is becoming warm. However, the
presence of CO2 in the atmosphere become redundant due to combustion engines and power
generation, so that the trapped solar heat more and more. As
a result, there was a significant increase in temperature in
earth. That is why the earth is getting warmer. When
the earth is hotter, weather changes are striking.
Some countries will be more moist, and others are more dry.
8. Acid Rain
Combustion
of coal on power plants produce waste gas which combines
with water in the atmosphere to form sulfuric acid clouds
and nitric acid. The clouds come down as acid
rain. acid rain causes damage to the leaves of plants and fish kills
in freshwater lakes.
