Listing
description:
Shale
oil is an unconventional
oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal
dissolution. These
processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil can be used
immediately as a fuel or upgraded to meet refinery feedstock specifications by adding hydrogen and removing impurities such as sulfur and nitrogen. The refined products can be used for
the same purposes as those derived from crude oil.
Detailed
description:
The term
"shale oil" is interchangeable, as it is used as well for crude oil
produced from shales of other very low permeability formations. However, for
avoiding the risk of confusion of shale oil produced from oil shale with crude
oil in oil-bearing shales, the International
Energy Agency recommends to use the term "light tight oil" and World Energy
Resources 2013 report by the World Energy Council uses
the term "tight oil" for
the latter.
History
Oil shale was one
of the first sources of mineral oil used
by humans.[3] Its earliest recorded use was
in Switzerland and Austria in the early 14th century.[4] In 1596, the personal physician
of Frederick
I, Duke of Württemberg wrote of its healing properties.[5] Shale oil was used to light the
streets of Modena, Italy at
the turn of the 17th century.[5] The British Crown granted a
patent in 1694 to three persons who had "found a way to extract and make
great quantities of pitch, tarr and oyle out of a sort of stone."[5][6][7] Later sold as Betton's British
Oil, the distilled product was said to have been "tried by divers persons
in Aches and Pains with much benefit."[8] Modern shale oil extractionindustries
were established in France during the
1830s and in Scotland during the
1840s.[9] The oil was used as fuel, as a
lubricant and lamp oil; the Industrial Revolution had
created additional demand for lighting. It served as a substitute for the
increasingly scarce and expensive whale oil.[5][10][11]
During the
late 19th century, shale-oil extraction plants were built in Australia, Brazil and the United States. China, Estonia, New Zealand,South Africa, Spain, Sweden and Switzerland produced shale oil in the
early 20th century. The discovery of crude oil in the Middle East during
mid-century brought most of these industries to a halt, although Estonia
and Northeast China maintained
their extraction industries into the early 21st century.[9][12][13] In response to rising
petroleum costs at the turn of the 21st century, extraction operations have
commenced, been explored, or been renewed in the United States, China,
Australia and Jordan.[13]
Extraction
process
Shale oil is
extracted by pyrolysis, hydrogenation, or thermal dissolution of oil shale.[14][15] The pyrolysis of the rock is
performed in a retort, situated either
above ground or within the rock formation itself. As of 2008, most oil shale industries perform
the shale oil extraction process after the rock is mined, crushed and
transported to a retorting facility, although several experimental technologies
perform the process in place (in-situ). The
temperature at which the kerogen decomposes into usable hydrocarbons varies
with the time-scale of the process; in the above-ground retorting process
decomposition begins at 300 °C (570 °F), but proceeds more rapidly
and completely at higher temperatures. Decomposition takes place most quickly
at a temperature between 480 and 520 °C (900 and 970 °F).[14]
Hydrogenation and thermal dissolution (reactive
fluid processes) extract the oil using hydrogen donors, solvents, or a combination of these. Thermal
dissolution involves the application of solvents at elevated temperatures and
pressures, increasing oil output by cracking the
dissolved organic matter. Different methods produce shale oil with different
properties.[15][16][17][18]
A critical
measure of the viability of extraction of shale oil lies in the ratio of the
energy produced by the oil shale to the energy used in its mining and
processing, a ratio known as "Energy Returned on Energy Invested" (EROEI).
A 1984 study estimated the EROEI of the various known oil-shale deposits as
varying between 0.7–13.3.[19] More recent studies estimates
the EROEI of oil shales to be 1–2:1 or 2–16:1 – depending on whether
self-energy is counted as a cost or internal energy is excluded and only
purchased energy is counted as input.[20] Royal Dutch Shell reported an EROEI of
three to four in 2006 on its in situ development in the "Mahogany Research
Project."[21][22]
The amount of
oil that can be recovered during retorting varies with the oil shale and the
technology used.[13] About one sixth of the oil
shales in the Green River Formation have
a relatively high yield of 25 to 100 US gallons (95 to 379 l; 21 to
83 imp gal) of shale oil per ton of oil shale; about one third yield
from 10 to 25 US gallons (38 to 95 l; 8.3 to 20.8 imp gal) per
ton. (Ten US gal/ton is approximately 3.4 tons of oil per 100 tons of
shale.) About half of the oil shales in the Green River Formation yield less
than 10 US gal/ton.[23]
The major
global shale oil producers have published their yields for their commercial
operations. Fushun Mining Group reports
producing 300,000 tons per year of shale oil from 6.6 million tons of
shale, a yield of 4.5% by weight.[24] VKG Oil claims to produce
250,000 tons of oil per year from 2 million tons of shale, a yield of
13%.[25] Petrobras produces in their Petrosix plant 550 tons of oil per
day from 6,200 tons of shale, a yield of 9%.[26]
The properties
of raw shale oil vary depending on the composition of the parent oil shale and
the extraction technology used.[27] Like conventional oil, shale
oil is a complex mixture of hydrocarbons, and it is characterized using bulk
properties of the oil. Shale oil usually contains large quantities of olefinic and aromatic hydrocarbons. Shale oil can also
contain significant quantities of heteroatoms. A typical shale oil composition
includes 0.5–1% of oxygen, 1.5–2% of nitrogen and 0.15–1% of sulfur, and some deposits contain more
heteroatoms. Mineral particles and metals are often present as well.[28][29] Generally, the oil is less
fluid than crude oil, becoming pourable at temperatures between 24 and
27 °C (75 and 81 °F), while conventional crude oil is pourable at
temperatures between −60 to 30 °C (−76 to 86 °F); this property
affects shale oil's ability to be transported in existing pipelines.
Upgrading
Although raw
shale oil can be immediately burnt as a fuel oil, many of its applications
require that it be upgraded. The differing properties of the raw oils call for
correspondingly various pre-treatments before it can be sent to a
conventional oil refinery
Particulates in the raw oil clog
downstream processes; sulfur and nitrogen create air pollution. Sulfur and nitrogen, along with
the arsenic and iron that
may be present, also destroy the catalysts used in refining. Olefins form insoluble sediments and
cause instability. The oxygen within the oil,
present at higher levels than in crude oil, lends itself to the formation of
destructive free radicals. Hydrodesulfurization and hydrodenitrogenation can
address these problems and result in a product comparable to benchmark crude oil Phenols can be first be removed by water
extraction.[36] Upgrading shale oil into
transport fuels requires adjusting hydrogen–carbon ratios by adding hydrogen (hydrocracking) or removing carbon (coking)
Shale oil
produced by some technologies, such as the Kiviter process, can be used without further
upgrading as an oil constituent and as a source of phenolic compounds. Distillate oils from the
Kiviter process can also be used as diluents for petroleum-originated heavy
oils and as an adhesive-enhancing additive in bituminous materials such asasphalt.
PRICE
$54/BARREL OR
$0.39/KG AND $0.18/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
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