CHAPTER 2 THE FOSSIL FUELS

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CHAPTER 2THE FOSSIL FUELS
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Fossil Fuels

• So called because they are fossilized remains of
  ancient plants (coal) and plant and animal life
  in ancient oceans (petroleum and natural gas)
• The energy to produce this material came from the
  suns radiant energy absorbed by the plants to
  store carbon through the process of
  PHOTOSYNTHESIS
• Subsequent pressure and heat over millions of
  years as the biomass became buried in the earths
  crust fossilized it to the five forms of abundant
  fossil fuels
• Petroleum - largest US source of fossil fuel
  energy (37.71Q)
• Natural Gas - second largest US source (22.10 Q)
• Coal - third largest US source, close to natural
  gas (21.70 Q)
• Shale oil - not yet exploited
• Tar sands - not yet exploited

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Overview of Fossil Fuel Demand and Resources (1)

• In 1999 the United States
• Consumed 96.6 Qbtu of energy
• Of which 81.56 QBtu were fossil fuels
• This represents 84.4 of our energy consumption

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Overview of Fossil Fuel Demand and Resources (2)

• The supply of fossil fuels is NOT unlimited
• Reserves vary with type of fuel
• Petroleum and natural gas about same and least
• Coal greatest
• Shale oil and tar sands also large reserves
• Availability time depends on which fuels are used
  most
• E.g. if all energy needs switched to coal, then
  reserves would be depleted much faster than with
  current coal usage.
• Rate of usage depends on cost which will rise as
  fuel type becomes scarce
• Also development of less common fossil fuel
  products will not occur until cost of
  conventional products rises

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Overview of Fossil Fuel Demand and Resources (3)

• At present consumption rates petroleum resources
  will be depleted
• In US by 2050 (Extended because of high level of
  imported oil)
• In world by 2080

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Petroleum

• Petroleum is the name given to the porous
  oil-bearing rock (from petr (rock) oleum (oil))
• The crude oil is found in the interstitial spaces
  in the rock

The oil is represented by the clear spaces and
water by the black coatings on the grains
(actually the reverse of reality) This diagram
shows why complete recovery of the oil from the
petroleum is unlikely The water/oil/sand sizes
are variable from well to well
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Oil Fields and Extraction

• Regions containing petroleum are called oil
  fields and are found in geological formations
  called anticlines
• The anticline must have an impermeable rock cap
  in a structure as shown below

Note The petroleum strata may be many hundreds
of feet below the surface Oil wells have been
drilled under the sea The importance of finding
the extent of the oil field Water normally
applies pressure to petroleum causing gas or oil
to gush out of the drilling pipe at first Even
with enhanced extraction techniques only 30 of
oil can be extracted from the petroleum
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US Oil - Then and now
Colonel Drake at first oil well in Titusville
Pennsylvania
Modern US oil refinery
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The Rise of the Oil Industry (1)

• Seepage of oil from some rock formations regarded
  as a curiosity.
• Colonel Drake drilled 69 ft at Titusville, PA
  and found copious oil.
• The oil then was called rock oil that was refined
  into kerosene, a hydrocarbon used in lamps and
  cooking.
• The development of electric lighting and
  saturation in the rock oil market nearly killed
  the early oil industry.
• Saved by the replacement of horses by
  automobiles, and the uses and amount of
  oil-derived fuels has proliferated since then.

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The Father of the Oil Industry
Goal To produce a consistent refined product -
standardized Organized the Standard Oil Co. of
Pennsylvania in 1868 Reorganized in 1870 and
bought up many smaller rivals In 1911 anti-trust
suit resulted in dissolution into many smaller
companies
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Other Early Oil Barons
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The Rise of the Oil Industry (2)

• Note ever increasing consumption and slowly
  diminishing production requiring increasing
  imports of oil.

Annual Energy Review, 1999
Note peak production in 1970 with the Alaskan
oil development making only a blip on the
production curve.
Annual Energy Review, 1999
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Concerns About Importing Oil

• Outside sources concentrated in countries with
  unstable governments who may be antagonistic to
  the US.
• Supply and prices out of control of US
• Maintenance of our imported resources are
  important enough to go to war to preserve them.
• Has led to the formation of a Strategic Reserve
  to carry us through a crisis for a limited time.
• The reserve amount remains constant, but the time
  it will last reflects the increased amount being
  imported as time progresses, i.e. increasing
  consumption.

Annual Energy Review, 1999
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How Long Will Our Oil Last?

• First plausible attempt to estimate the amount of
  oil in US was made in 1956 by M. K. Hubbert - a
  petroleum geologist.
• The plot shows the cumulative discovery of a
  finite resource such as oil.
• Slope of curve is production rate
• Upper level is all that can be extracted - called
  Q
• Plot of production results in a bell-shaped curve
• Hubbert predicted peak in 1966-71 - it peaked in
  1970 ...

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Larger view Next slide
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US Oil Production Decline
Estimated oil remaining 56 years at 2x109 bbl/yr
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Enhanced Recovery of Oil (1)

• 15 - 20 can be extracted by natural pressure and
  subsequent pumping
• Secondary extraction techniques involve pumping
  water of air into the oil field to drive more oil
  to the well.
• May add another 15 to recovery
• Note energy is used to perform the pumping

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Enhanced Recovery of Oil (2)

• Tertiary techniques involve adding material to
  the oil to reduce its surface tension or its
  viscosity
• Surface tension
• Detergent pumped into oil field followed by
  secondary methods
• Viscosity
• Dissolve CO2 in oil under pressure
• Heat oil by steam injection
• Heat by controlled underground burn of some of
  the oil
• These methods are experimental - no firm figures
  on enhancement to recovery, but could be in 20-75
  billion bbl range
• All enhanced recovery uses energy (detracting
  from the energy recovered) and also cost money
  driving up the price of oil

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Selected World Gasoline Prices (Apr. 2001)
1.85?
3.31?
3.67?
2.83?
4.12?
3.66?
1.56?
3.61?
Arrows indicate change since Feb 2000
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Oil Refining (1)

• The substance extracted from the ground is a
  viscous black fluid called crude oil.
• It is not usable in its extracted form and must
  be processed to obtain usable products from the
  hundreds of hydrocarbons of which it is composed.
• This processing is called refining and occurs at
  oil refineries such as those near the SLC
  airport.
• The basic process is called fractional
  distillation a process that allows the separation
  of the different parts of the mixture according
  to their boiling point.
• Most of the fluid parts of the crude oil have
  boiling points less than 400C, so it is
  initially heated to that temperature to transfer
  the required components in vapor form into the
  distillation column.
• A diagram of the a distillation column is shown
  on the next slide

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Oil Refining (2)
When vapor gets to level where it reaches its
boiling point it condenses to a liquid and is
collected. Residual gas does not condense and
is sometimes left to burn off in the atmosphere
(c.f. SLC refineries) Residues are tar and a
coke-like material and are collected.
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Oil Refining (3)
Some of the common products of oil refining
are tabulated below
Proportion of gasoline can be increased by
breaking larger molecules into smaller ones -
called cracking Other molecules are induced
to join together into polymers the basis of the
plastics industry (polymerization).
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Oil Refining (4)
CnH2n2
The alkane series of hydrocarbon molecules are
found in crude oil The names are familiar, and
the proportions extracted from the oil can be
controlled by the cracking process
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A Modern Oil Refinery
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Oil/Oil Products Distribution

• Crude oil to refineries
• Oil tanker ships - super-tankers
• Environmental hazard
• Tanker trucks - road or rail
• Probably the safest
• Pipeline - often very long, e.g. Alaska pipeline
• Environmental effects
• Less easy to protect from sabotage
• Refinery products (primarily gasoline)
• Tanker trucks
• Large distribution network to the public is in
  place

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Petroleum consumption by sector
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Another Fuel Crisis ?

• Last Fall Headlines
• Europe Fuel Protests Grow, Pumps Run Dry
• Tuesday September 12 912 AM ET
• Blair convenes crisis talks to calm fuel frenzy
• Tuesday September 12, 1244 PM
• Fuel protest to bring London to
  standstill-farmers
• Tuesday September 12, 1225 PM
• Pumps run dry amid fuel protest chaos
• September 11, 2000
• Fuel protest spreads across Europe
• September 11, 2000

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Deja Vu
European Fuel Shortage 2000
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Natural Gas

• The existence of natural gas has been known for
  thousands of years
• It was impractical to use it as a prime source of
  energy until the technology to produce gas-tight
  welds at the joints of large diameter was
  developed after World War II
• Prior to that the gas was vented or burned off at
  the well head
• With the development of a network of pipelines to
  distribute the gas it became a very popular and
  inexpensive fuel
• There are increasing numbers of vehicles using
  tanked natural gas a their fuel
• It consist mainly of the gas methane (CH4) -
  first in the alkane series
• 5-20 ethane (C2H6)
• Additives to provide an odor

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Comparative Cost of Natural Gas

• Dollar costs
• Natural Gas 6.14 / 1000 cu ft
• Gasoline 1.30 / US gallon
• Electricity 0.071 / kWh
• Cost per energy unit (J) (Using conversions from
  book)
• Natural gas 6.14 / 1.09 x 109 5.63 x 10-9 /J
• Gasoline 1.30 / 1.32 x 108 9.85 x 10-9 /J
• Electricity 0.071 / 3.6 x 106 19.7 x 10-9 /J
• Cost ratios to natural gas
• Gasoline 1.75
• Electricity 3.50

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Natural Gas Usage
Note the trend to use more than is produced
Imports from Canada by pipeline and Algeria by
cryogenic hold ships
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Users of Natural Gas in USA
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Natural Gas Pipe Grid
Fundamentals of the Petroleum Industry Robert O.
Anderson, 1984
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Coal

• Coal was formed from ancient, large plants
  growing about 350 million years ago
• After they died and fell to the ground, the
  initial aerobic decay
• released much of the decayed material as gas
• Replaced by anaerobic decay after it was covered
• material remain solid and slowly evolved into the
  product we know as the result of heat and
  pressure under the ground
• in other words it was fossilized
• Coal is now found in seams at an average depth of
  300 ft
• Earth movements also can bring access to the
  seams to the surface
• The seam thickness varies from 2 - 100 ft

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Coal Extraction
Open cast mining
Underground Mine
Mine tour
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Coal Types and Energy Content
Peat is an even lower grade than Lignite -
Used as a low grade fuel in many parts of the
world
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Coal End Users (1950-2000)
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Coal Reserves

• Coal is the most plentiful fossil fuel
• The technology to convert its chemical energy to
  heat energy is well established
• Pollution aspects are significant beyond the CO2
  problem with all fossil fuels
• Acid rain resulting from sulfur in the coal is a
  problem
• Smog from particulates and aerosols
• Coal reserves concentrated mainly in US and FSU

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Coal Gasification and Liquefaction

• What if oil and gas were used up, could coal be
  used to replace them?
• Gasification
• Used since Victorian era (gaslamps)
• Now replaced by natural gas
• Liquefaction
• Developed in Germany in WWII and S. Africa during
  trade embargo.
• Product to replace gasoline can be produced for
  vehicular use.
• Much more expensive than present gasoline prices.
• Needs large capital investment for conversion
  plants.

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Shale Oil (1)

• Organic material in ancient lakes deposited and
  over 50 M years formed a rock call oil shale or
  marlstone.
• The rock contains an organic compound called
  kerogen which can be extracted by heating the
  rock.
• Further refining can produce gasoline, fuel oil
  and coke
• Resources are usually quoted as equivalent
  barrels of oil.
• US deposits around Utah, Wyoming, Colorado
  confluence (see fig.2.8 in textbook)
• Estimates of resource are 600-2000 billion bbl
• Compare with Q for petroleum oil of 280
  billion bbl

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Shale Oil (2)

• Processing
• Heating results in 35 expansion - cannot put the
  residue back
• Requires 3 gallons of water for every one gallon
  of oil
• The US deposits are in a very arid region of the
  country
• Cost
• Pilot plants have been built, costs will be
  greater than for petroleum oil products
• At present production is not economic, but with
  rising oil prices ...

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Tar Sands

• A sandy deposit containing a very viscous organic
  fluid called bitumen
• Too thick to be extracted like oil
• Must be mined and the bitumen separated by
  heating
• The bitumen can then be refined like petroleum
  oil to extract fuel products
• Extraction process relatively inexpensive
• Energy content such that two tons of tar sands
  needed to produce one barrel of oil

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Learning Objectives (1)

• Know the five forms of fossil fuels used or
  considered for energy sources
• Understand that the form of energy in fossil
  fuels is chemical energy
• Know the origins of fossil fuels and be aware of
  the huge difference in the time scales of
  production and usage.
• Be aware of the high reliance of the USA on
  fossil fuels (gt80)
• Understand that the lifetime of fossil fuels is
  limited on a generation time scale
• Know what is meant by petroleum and its relation
  to oil
• Know what is meant by an oilfield and how oil is
  extracted from it.
• Be aware of the increasing gap between oil
  production and consumption and our increasing
  dependence on imported oil
• Be aware of the very low price of gasoline in the
  USA and its impact on oil consumption
• Know about the strategic oil reserve maintained
  since the late 1970s
• Know the name of the geologist who successfully
  predicted future oil supplies
• Know what is meant by Q
• Be aware of the curve of the production rate of
  oil and where we are presently on that curve.

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Learning Objectives (2)

• Know that conventional oil recovery extracts only
  15-20 of the oil in an oilfield.
• Know what secondary and tertiary techniques exist
  to extract oil beyond pumping.
• Know what is meant by oil refining and its
  purpose.
• Be familiar with the principle of fractional
  distillation.
• Have some knowledge of the types of compounds
  which are found in oil.
• Be aware that the type of product can be
  controlled by cracking or polymerization
  (plastics).
• Know the methods that are used to transport oil
  and oil products
• Know what is meant by natural gas.
• Be aware of the desirable properties of natural
  gas as an energy source
• Be familiar with the global distribution of
  natural gas
• Be aware that our growing consumption is
  exceeding our production
• Know that industry is the largest user of natural
  gas.
• Be aware that the development of sealed pipeline
  technology allowed the development of natural gas
  as an energy source.
• Know that there is an extensive natural gas
  pipeline grid over the country.

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Learning Objectives (3)

• Know what is meant by coal, its origins and the
  form it is found in the ground.
• Know the two methods of extracting coal from the
  ground.
• Be aware of the fact that there are different
  types of coal with differing energy content
• Be familiar with the types of pollution resulting
  from burning coal
• Be aware of the growth of the use of coal in the
  electric industry sector in recent years.
• Know that the USA and FSU have the greatest coal
  reserves in the world.
• Know what is meant by coal gasification and coal
  liquefaction
• Know what shale oil is and its prospects for and
  energy source
• Know what tar sands are and their prospect for an
  energy source