The Fossil Fuels

1. Introduction

2004 World Wide Energy Sources

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

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.

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.

• 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.

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

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

• “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.

• 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.

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

remaining for future production.

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.

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.

Prudhoe Bay oil field is the largest

oil field in North America, originally

containing approximately 25 billion

barrels of oil.

Q∞

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.

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.

Economically Recoverable

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

40%

Table 2.2 Major Oil-

Producing 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

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

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.

• 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.

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

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.

• 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.

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.

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

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.

Oil Spill

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.

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.

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

Ten Largest Oil Spills

• 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.

Environmental Effects of Oil Spill

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 $12.83/106 Btu

Gasoline $14.80/106 Btu

Electricity $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 pipe-

laying 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.

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.

1973

1986

• 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.

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.

10. The Natural Gas Resource Base in the U.S.

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

swamp

• 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

Anthracite 350 Myrs 95% C

Bituminous 300 Myrs 50-80% C

Lignite 150 Myrs 50% C

Peat low energy content

无烟煤

烟煤

褐煤

泥炭

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

Figure 2.7 Annual production of coal in the U.S. since 1870.

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.

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?

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

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.

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 , and to some extent .

propane, ethane

propane, methane

butane, ethane

methane, ethane

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