Where does gasoline for US consumers come from?
22-11-07
The fact that you purchase gasoline from a given company does not
necessarily mean that the gasoline was actually produced by that particular
company’s refineries.
The United States consumes over 20 mm barrels (840 mm gallons) of petroleum
products each day, almost half of it in the form of gasoline used in over
200 mm motor vehicles with combined travel over 7 bn miles per day.
Gasoline is made from crude oil, which was formed from the remains of tiny
aquatic plants and animals that lived hundreds of millions of years ago.
These remains were covered with layers of sediment, which over millions of
years of extreme pressure and high temperatures became the mix of liquid
hydrocarbons (an organic chemical compound of hydrogen and carbon) that we
know as crude oil.
Because crude oil is made up of a mixture of hydrocarbons, refineries break
down these hydrocarbons into different products. These “refined products”
include gasoline, diesel fuel, heating oil, jet fuel, liquefied petroleum
gases,residual fuel oil, and many other products.
The most basic refining process is aimed at separating the crude oil into
its various components. Crude oil is heated and put into a still -- a
distillation column -- and different hydrocarbon components boil off and can
be recovered as they condense at different temperatures. Additional
processing follows crude distillation, changing the molecular structure of
the input with chemical reactions, some through variations in heat and
pressure, some in the presence of a catalyst, a substance that increases the
rate of a chemical reaction without being consumed in the reaction.
The characteristics of the gasoline produced depend on the type of crude oil
that is used and the setup of the refinery at which it is produced. Gasoline
characteristics are also impacted by other ingredients that may be blended
into it, such as ethanol. The performance of the gasoline must meet industry
standards and environmental regulations that may depend on location.
In 2005, US refineries produced over 90 % of the gasoline used in the United
States. Although the United States is the world’s third largest crude oil
producer, less than 35 % of the crude oil used by US refineries was produced
in the United States. Net petroleum imports (imports minus exports) account
for 60 % of our total petroleum consumption.
About 50 % of our petroleum imports are from countries in the Western
Hemisphere, with 17 % from the Persian Gulf, and 19 % from Africa and 14 %
from other regions.
From refinery to consumer
After crude oil is refined into gasoline and other petroleum products, the
products must be distributed to consumers. The majority of gasoline is
shipped first by pipeline to storage terminals near consuming areas, and
then loaded into trucks for delivery to individual gas stations. Gasoline
and other products are sent through shared pipelines in “batches.”
Since these batches are not physically separated in the pipeline, some
mixing or “commingling” of products occurs.This is why the quality of the
gasoline and other products must be tested as they enter and leave the
pipeline to make sure they meet appropriate specifications. Whenever the
product fails to meet local, state, or federal product specifications, it
must be removed and trucked back to a refinery for further processing.
After shipment through the pipeline, gasoline is typically held in bulk
storage terminals that often service many companies. At these terminals the
gasoline is loaded into tanker trucks destined for various retail gas
stations. The tanks in these trucks, which can typically hold up to 10,000
gallons, usually have several compartments, enabling them to transport
different grades of gasoline or petroleum products.
The truck tank is where the special additive packages of gasoline retailers
get blended into the gasoline to differentiate one brand from another. In
some areas, ethanol may be “splash blended” in the tanker to meet
environmental requirements. When the tanker truck reaches a gas station, the
truck operator unloads each grade of gasoline into the appropriate
underground tanks at the station.
Grades and formulations
Service stations usually sell several grades of gasoline: premium,
mid-grade, and regular. These grades have different “octane ratings” which
reflect the gasoline’s anti-knock properties. The owner’s manual for your
car tells you what grade of gasoline your car needs. Most cars can run on
regular gasoline, which is the cheapest.
Besides the different grades of fuel, gasoline sold by a single company may
differ depending on location or season. Some areas of the country are
required to use gasoline that is specially formulated to reduce certain
emissions. Environmental programs, aimed at reducing carbon monoxide, smog
and air toxics, include the Federal and/or State-required oxygenated,
reformulated, and low-volatility (evaporating more slowly) gasolines. These
distinct and area specific gasoline requirements mean that gasoline is not a
homogenous product nationwide. Gasoline produced for sale in one area may
not be suitable for use in another area that has a supply shortage.
Can I tell which country or State the gasoline at my local station comes
from?
The Energy Information Administration (EIA) cannot definitively say where
gasoline at a given station originated since EIA does not collect data on
the source of the gasoline sold at retail outlets. The name on the service
station sign does not tell the whole story.
The fact that you purchase gasoline from a given company does not
necessarily mean that the gasoline was actually produced by that particular
company’s refineries. While gasoline is sold at about 167,000 retail outlets
across the nation, about one-third of these stations are “unbranded” dealers
that may sell gasoline of any brand.
The remainder of the outlets are “branded” stations, but may not necessarily
be selling gasoline produced at that company’s refineries. This is because
gasoline from different refineries is often combined for shipment by
pipeline, and companies owning service stations in the same area may be
purchasing gasoline at the same bulk terminal.
In that case, the only difference between the gasoline at station X versus
the gasoline at station Y may be the small amount of additives that those
companies add to the gasoline before it gets to the pump. Even if we knew at
which company’s refinery the gasoline was produced, the source of the crude
oil used at that refinery may vary on a day-to-day basis. Most refiners use
a mix of crude oils from various domestic and foreign sources. The mix of
crude oils can change based on the relative cost and availability of crude
oil from different sources.
Can I tell which companies purchase imported crude oil or gasoline?
While EIA cannot identify which companies are selling imported gasoline, EIA
does collect data on which companies import crude oil and refined products.
However, the fact that a given company imported crude oil or gasoline does
not mean that those particular imports will end up being sold to motorists
as that company’s brand of gasoline. The origin of the crude oil that a
refinery processes is determined by market economics at a given time and may
change from month-to-month or even day-to-day.
Company-level import data can be found at: http://www.eia.doe.gov/oil_gas/fwd/cli.html
Source: www.energypublisher.com / EIA |