oil spill

The Fossil Fuels
1. Introduction
Our reliance on fossil fuel
is overwhelming.
We will explore how each
fuel was formed, the
history of its use and
resource development,
and projections for its use
in the future.
Petroleum
Natural gas
Coal
Shale oil
Tar sand
2004 World Wide Energy Sources
2. Petroleum
Petroleum is a naturally occurring, flammable liquid found in rock formations in
the earth consisting of a complex mixture of hydrocarbons of various molecular
weights, plus other organic compounds. It includes liquid crude oil and natural
gas liquid as well as the common fuels propane and butane.
Formation of petroleum
•
The energy input to the fossil fuels came to the earth hundreds of
millions of years ago as radiant energy.
•
The radiant energy was captured in plant life on earth through
photosynthesis.
•
The plant and animal matter in the ancient sea accumulated and
decomposed under the cover of sand or mud which created conditions
of high temperature and pressure and low oxygen level.
•
Hydrocarbon molecules were created in this way, some of them solid,
some of them liquid, and some of them gas.
•
The liquid and gaseous hydrocarbons could travel rather large distance
in the porous sedimentary rock. Under the influence of the geologic
structures and gravity, some of the hydrocarbon material accumulated
in the geologic traps.
Figure 2.1 A typical geologic formation in which oil and natural gas are found.
The gas if found above the oil, and the oil above water, all interspersed in a porous
formation.
Exploration of petroleum deposits
•
One of the geophysical exploration methods: sound waves from an
explosion or from vibrating weights are sent down to the earth.
•
Sound waves can be partially reflected back by the interface between
layers of rock with different acoustical properties and read by
geophones （地音探测仪）.
•
The exploration geologists can determine if an underground geological
formation is likely to contain a significant reservoir of petroleum.
•
The real proof of an oil or natural gas deposit must be obtained by
drilling.
•
Only about one commercial well is found in the US for every nine wildcat
(first well drilled in a new area) drillings.
•
Then the total amount of the oil that can be extracted from the new area
is estimated and added to what is called the proved reserve.
3. History of the Production of Petroleum in the US
Edwin Laurentine Drake
•
“Colonel” Drake started the whole thing off
in 1859 at Titusville, Pennsylvania.
•
The main problem at that time was to find
suitable containers for the oil (stone oil, 石
油) because the barrels cost more than the
oil was worth.
•
Refining of the oil produced kerosene 煤油
which had a ready market for heating,
cooking, and lighting.
Born
March 29, 1819
Greenville, New York
Died
November 9, 1880 (aged 61) •
Bethlehem, Pennsylvania
Nationality
American
Other names
Colonel Drake
Known for
Petroleum exploration
•
In 1862, 3 million barrels of oil were
produced from more than 75 wells in
Pennsylvania.
By 1909 the US was producing 500,000
barrels per day, more than was being
produced by all other countries combined.
Annual production climbed
fairly steadily for 110 years
until 1970. This was the year
that the Prudhoe Bay field
was brought on-line through
the Alaskan pipeline.
Q∞
Since 1948 the US has
imported more oil each year
than it has exported.
Drilling for oil in the US has
been reduced in the last 25
years because the chances
of producing a paying well
have become less.
Figure 2.2 Annual rate of petroleum production in the
US, including Alaska. The rectangle at the right has an
area representing the 134 billion barrels estimated to be
Prudhoe Bay oil field is the largest
remaining for future production.
oil field in North America, originally
containing approximately 25 billion
barrels of oil.
4. Petroleum Resources of the US
Q∞: the total resource that is available over all time from the beginning
of the oil industry to the exhaustion of the resource.
Economically Recoverable
Figure 2.3 History of cumulative discovery and production of finite resource
consumed to depletion. For oil in the US, production has generally followed
discovery by about 11years.
Estimating the total petroleum resource has been an ongoing endeavor of the
oil companies as well as of government agencies such as the US Geological
Survey (USGS).
Table 2.1 Estimates of Undiscovered Recoverable Oil and Natural Gas in the US.
Oil
(Billion Barrels)
Natural Gas
(Trillion Cubic Feet)
As of the end of 2002, a total of 190x109 barrels of crude oil had been produced
in the US. When the future resource of 134 (105+29) x109 barrels is included, a
value of 324 x109 barrels is obtained for Q∞.
The US is now consuming about 6.7x109 barrels per year of petroleum, so at
that rate the oil resource would be completely exhausted in 20 years. ???
•
After a well stops producing by normal exaction processes, about 70% of
the petroleum is left behind the ground.
•
Secondary recovery involves pumping either water or gas into the
surrounding area to force more oil toward the well (another 15%).
•
Tertiary techniques are used to overcome the two effects that lock the oil
in: interfacial tension and viscosity.
Viscosity: CO2 or steam injection
Surface tension: detergents injection
•
Enhanced recovery is expensive and can have unfortunate environmental
consequences.
5. World Production of Petroleum
Table 2.2 Major OilProducing Countries and
their current production
rates, proved reserves,
and number of wells.
The total world production
in 2003 was 68,561x103
bbl/day.
OPEC: Organization of
Petroleum Exporting
Countries
40%
5. World Production of Petroleum
According to a recent estimation:
World oil production will peak between 2010 – 2020 in the
range of 27 to 36 billion barrel per year.
World wide Q∞: 3.3x103 billion barrel
6. The Cost of Gasoline in the US
•
Gasoline in the US is relatively inexpensive, comparable in
price to bottled water.
•
In constant 2005 dollars: $ 3.00 per gallon for 2005, $ 2.80 for
1980, and $ 2.10 for 1947
High Production in the world & Low tax of gasoline in the U.S.
The term Constant dollars refers to a metric for valuing the
price of something over time, without that metric changing due
to inflation or deflation. The term specifically refers to dollars
whose present value is linked to a given year.
Constant dollars are used to compare the "real value" of an
income or price to put the "nominal value" in perspective.
For example, who was making more money, your father who made
$5,000 at his first job in 1957, or you when you started at $18,000 in
1986?
The inflation calculator at the Bureau of Labor Statistics shows that
$5,000 in 1957 has a value of $19,501.78 in 1986 dollars or that
$18,000 in 1986 has a value of $4,614.96 in 1957 dollars. So dad was
making more money, even though $18,000 looks larger than $5,000.
Any year can be used as a baseline for comparing two years as long
as it is consistent. For example, both salaries could be converted into
1970 dollars. Then the $18,000 becomes $6,372.26 in 1970 dollars,
and the $5,000 becomes $6,903.91 in 1970 dollars. The relative
position stays the same no matter what year is used as a baseline.
7. Petroleum Refining
•
The crude oil need to be treated
to generate products that are
essential for an industrialized
society.
•
The first step in the process is
fractional distillation.
Figure 2.4 A fractionating column
for the distillation of petroleum. The
temperature of the column decreases
going up from the bottom to the top
so that the less volatile components
are condensed near the bottom and
the more volatile components are
condensed toward the top of the
column.
400 ºC
Figure 2.5 A gas and oil refinery in Scotland,
showing a complex array of modern chemical
technology. Several fractional distillation towers
are visible in this view.
Table 2.3 Products of fractional distillation, their molecular size, boiling
point range, and typical uses.
Table 2.3 The Alkane Series of Hydrocarbons (CnH2n+2)
The mix of products from a distillation column is not normally the same as
the mixture demanded by the marketplace.
Producing gasoline with more octane:
Thermal cracking – breaking up the heavy molecules into lighter ones
Polymerization – joining light hydrocarbon molecules and forming heavier ones
Catalytic conversion
Oil Spill
Oil spreading north-east from the leaking Deepwater Horizon
well in the Gulf of Mexico 2010. The oil appears as a maze of
silvery-grey ribbons in this image. The location of the leaking
well is marked with a red dot.
An oil spill is a release of a liquid petroleum hydrocarbon into the
environment due to human activity, and is a form of pollution. The
term often refers to marine oil spills, where oil is released into the
ocean or coastal waters. Oil spills include releases of crude oil from
tankers, offshore platforms, drill rigs and, as well as spills of their
by-products (such as gasoline, diesel), and heavier fuels used by
large ships, or the spill of any oily refuse or waste oil. Spills may
take months or even years to clean up.
Ten Largest Oil Spills
Location
Date
Tons of crude oil
United States,
Kern County, CA
May 14, 1910 – September,
1911
1,200,000
United States,
Gulf of Mexico
April 20, 2010 – July 15, 2010
560,000-585,000
Iraq and Kuwait,
Persian Gulf
January 23, 1991
270,000–820,000
Mexico,
Gulf of Mexico
June 3, 1979 – March 23, 1980
454,000–480,000
Trinidad and Tobago
July 19, 1979
287,000
Uzbekistan
March 2, 1992
285,000
Iran,
Persian Gulf
February 4, 1983
260,000
Angola,
1300 km offshore
May 28, 1991
260,000
South Africa,
Saldanha Bay
August 6, 1983
252,000
Environmental Effects of Oil Spill
•
The oil penetrates into the feather of birds, reducing its insulating ability, thus
making the birds more vulnerable to temperature fluctuations. It also impairs
birds' flight abilities to forage and escape from predators.
•
As birds attempt to preen, birds typically ingest oil that covers their feathers,
causing kidney damage, altered liver function, and digestive tract irritation.
•
Most birds affected by an oil spill die unless there is human intervention.
•
Marine mammals exposed to oil spills are affected in similar ways as seabirds.
Oil coats the fur of sea otters and seals, reducing its insulation abilities and
leading to body temperature fluctuations and hypothermia. Ingestion of the oil
causes dehydration and impaired digestions.
•
Because oil floats on top of water, less sunlight penetrates into the water,
limiting the photosynthesis of marine plants and phytoplankton. This, as well
as decreasing the fauna populations, affects the food chain in the ecosystem.
•
There are three kinds of oil-consuming bacteria. Sulfate-reducing bacteria
(SRB) and acid-producing bacteria are anaerobic, while general aerobic
bacteria (GAB) are aerobic. These bacteria occur naturally and will act to
remove oil from an ecosystem, and their biomass will tend to replace other
populations in the food chain.
8. Natural Gas
Composition: principally methane, CH4, typically 80 to 95%, and usually
contains ethane, C2H6, along with small amounts of heavier
hydrocarbons
Reasons for increasing use of natural gas:
1. There have been improvements in the technologies for exploration and
production and the resource base has increased.
2. Relative to other fossil fuels, natural gas releases less harmful
combustion products per unit of energy produced.
3. There have been a number of new applications of natural gas such as
motor fuel for transportation that increase the demand.
4. On a Btu basis, compared to oil and electric energy, natural gas is a
less costly source of energy.
Prices in 2004: Natural gas
Gasoline
Electricity
$12.83/106 Btu
$14.80/106 Btu
$26.08/106 Btu
9. The History of Use of Natural Gas
•
The long history of the use of natural gas dates back to the sixth
century B.C. in China and Japan, where gas was transported to
lighting fixtures through bamboo pipes.
•
In early years, much of the natural gas emerging from oil wells was
wasted by venting it into the atmosphere or flaring it at the source.
•
During World War II, and particularly in the years following the war,
there was a rapid expansion of the natural gas industry in the U.S.
•
Development of large diameter welded steel pipes and improved pipelaying techniques made the rapid expansion possible.
•
The economic advantage of natural gas over other fuels, as well as its
convenience and cleanliness, drove widespread adoption of this fuel.
1973
1986
Figure 2.6 Annual rate of natural gas production in the US .The rectangle
at the right has an area representing the 871 tcf of natural gas estimated to be
remaining for future production.
•
The use of natural gas as a fuel entirely avoids air pollution due
to sulfur and particulates. Increased concerns about air pollution
from coal have made natural gas the fuel of choice.
•
A substantial fraction of the power plants now under construction
will use natural gas as a boiler fuel or newer types of gas turbine.
•
The new gas turbines that use the combustion of natural gas to
drive turbines directly have an efficiency of 45% or higher for
converting the energy in the fuel to electricity.
•
Natural gas is also coming into use as a motor fuel in cars, trucks,
and buses.
10. The Natural Gas Resource Base in the U.S.
•
The cumulative production of natural gas in the U.S. from the
beginning of the industry through 2004 is about 1060 tcf.
•
The proved reserves at the end of 2003 are about 189 tcf, and the
estimated undiscovered resource is about 682 tcf.
•
Q∞ ≈ 1931 tcf
•
In 2002, a volume of about 23 tcf of natural gas was consumed in
the U.S. About 20 tcf was produced domestically, and nearly 4 tcf
came by pipeline from Canada.
•
At current rates of consumption, the remained resource can be used
for 30 years. However, this number will be shortened considerably if
the consumption rate increase.
10. The Natural Gas Resource Base in the U.S.
Coalbed methane:
•
produced at the same time that coal was formed
•
has been hazardous in the underground coal mining
•
being extracting from the coalbeds
In 2000, about 1.2 tcf of coalbed methane was produced.
11. The Natural Gas Resource
Base for the World
•
The total proved reserves of natural gas
for all countries is about 6400 tcf.
•
One of the major hindrances to wider use
of natural gas on a worldwide basis is the
lack of extensive pipeline systems to bring
the fuel to consumers.
•
Transporting natural gas as a liquid at low
temperature (-260oF at atmospheric
pressure) is technically possible, but the
process and the specialized ships are
expensive and there is a potential for
explosion.
12. The Formation of Coal
•
Coal has its origin in the abundant plants growing 350 million years ago.
•
The carbon in the decayed plants accumulated in layers at the bottom of the
swamp.
•
The dead plant material was decomposed by aerobic and anaerobic bacteria.
•
The first stage of coal formation produces peat.
•
In time the peat material was heated and compressed by the over burden and
carbon rich coal was formed
无烟煤 Anthracite
swamp
350 Myrs
95% C
烟煤
Bituminous
300 Myrs
50-80% C
褐煤
Lignite
150 Myrs
50% C
泥炭
Peat
low energy content
13. Coal Resources and Consumption
The size of the coal resource is more readily determined than that for oil or
natural gas because the coal beds tend to occur quite near the surface ( 300ft
average ) over large areas that are well documented.
There is a vast amount of coal in the world and a substantial fraction of the
proved reserves is located in the U.S..
Table 2.7 Estimated Worldwide Coal Proved Reserves.
•
In discussing coal, it is important to distinguish between proved
reserves and the total resource.
Resource: the total amount of coal known to be in the ground
Proved reserves: the amount that is recoverable under existing
economic and operating conditions
•
The proved reserves of coal in the US are about 250x109
tonnes. With the annual consumption rate of 985x106 tonnes
(2000), it would last 261 years.
1 ton = 2000 lb = 0.907 tonne
Table 2.6 Analysis of Some Coals of the United States
NOx
In the past 35 years, coal production has increased considerably to double
what it was in the previous decades in the U.S.. The major use of coal
now is for production of steam in electric power plants.
Figure 2.7 Annual production of coal in the U.S. since 1870.
Major environmental problems of coal production:
1. Environmental impact of surface mining
2. The effect of CO2 emissions on global climate
3. Health effects of SO2 and particulate emissions
14. Shale Oil （页岩油）
•
Oil shale, an organic-rich fine-grained sedimentary rock, contains
significant amounts of kerogen (油母岩质, a solid mixture of organics)
from which technology can extract liquid hydrocarbons – shale oil.
•
Estimates of global deposits range from 2.8 trillion to 3.3 trillion barrels of
recoverable oil. (1.8 trillion barrels for petroleum)
•
Kerogen requires more processing to use than crude oil, which increases
its cost as a crude-oil substitute. At the same time, oil-shale mining and
processing involve a number of environmental issues, such as land use,
waste disposal, water use, waste-water management, greenhouse-gas
emission and air pollution.
•
Oil shale has gained attention as an energy resource
as the price of conventional sources of petroleum has
risen and as a way for some areas to secure
independence from external suppliers of energy.
25 gallons oil per ton of shale, low energy density
15. Tar Sand
•
Tar sands (沥青沙) are deposits of sand impregnated with a thick, tarlike
hydrocarbon substance which is a very viscous crude oil called bitumen (沥青).
•
Tar sands are mined as a solid material and transported to a processing plant
where the bitumen is extracted by steam or hot water. Bitumen can be refined
by the same method used for heavy crude oil.
•
Known deposits of tar sands are
sufficient in size to make an impact on
the petroleum resource picture.
•
It takes two tons of tar sands to produce
one barrel of oil. The energy density in
terms of Btu/ton is similar to that of oil
shale but far less than for coal.
Review Exercises - 2:
Review Exercises - 2:
Why are fossil fuels not being created in nature fast enough to keep
up with our use of them?
It took hundreds of millions of years for plant and animal matter to be
converted into the hydrocarbon compounds (fossil fuel) under
conditions of high temperature and pressure under the earth’s surface.
What is the definition of Q∞ for a certain fossil fuel?
Q∞ is the total resource of a fossil fuel that is available (economically
recoverable) over all time from the beginning of its industrial production
to the exhaustion of the resource.
What are the major environmental problems of coal production?
1. Environmental impact of surface mining
2. The effect of CO2 emissions on global climate
3. Health effects of SO2 and particulate emissions
Gasoline costs nearly twice as much per Btu as does natural gas. Why then,
do we power our cars and trucks predominantly with gasoline rather than
natural gas?
Natural gas must be compressed to liquid form for practical use. There is a
potential for explosions.
Why is 2/3 of the petroleum left in the ground after the primary extraction
process comes to and end? Can this problem be overcome?
There are two effects that lock the oil in: interfacial tension and viscosity.
Enhanced recovery methods include pumping either water or gas into the
surrounding area to force more oil toward the well, injecting CO2 or steam to
decrease viscosity, injecting detergents to decrease surface tension.
What is oil shale and how can it be converted into useful fuels for
transportation and heating?
Oil shale, an organic-rich fine-grained sedimentary rock, contains significant
amounts of kerogen from which technology can extract liquid hydrocarbons
– shale oil. The shale oil can be further refined to produce gasoline, fuel oil.
It has been estimated that a person can perform continuous manual labor
at a power of 50 watts for an 8 hour working day. How many pounds of
coal contain the energy equivalent of the useful physical labor a person
can perform in this time period? (There are about 13,000 Btu in a pound of
coal.)
50W×(8×3600S) = 1440000J
1440000J÷(13000×1055)J/pound = 0.1 pound
What is the oldest form of coal?
a. bituminous b. anthracite c. lignite d. peat
In the United States the total energy consumed per year per person
is the equivalent of about how many barrels of oil?
a. 5.8 b. 58 c. 580 d. 5800
The declining order of importance for the various energy sources in
the world is:
natural gas, oil, coal, nuclear, hydro
oil, coal, natural gas, nuclear, hydro
oil, natural gas, coal, hydro, nuclear
coal, oil, natural gas, hydro, nuclear
Natural gas consists mostly of
propane, ethane
propane, methane
butane, ethane
methane, ethane
, and to some extent
.
The coal that we burn in our power plant today represents solar
energy trapped in organic molecules about years ago.
a. 300,000 b. 3,000,000 c. 300,000,000 d. 3,000,000,000
The oil that we burn in our car today represents solar energy
trapped in organic molecules about years ago.
a. 200,000 b. 2,000,000 c. 200,000,000 d. 2,000,000,000
In tar sands, the organic material that contains the oil and that
surrounds the grains of sand is:
a. kerogen, b. kerosene, c. marlstone, d. bitumen, e. paraffin