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CHAPTER 2 THE FOSSIL FUELS

COAL. NATURAL GAS. OIL. CHAPTER 2 THE FOSSIL FUELS. 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)

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CHAPTER 2 THE FOSSIL FUELS

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  1. COAL NATURAL GAS OIL CHAPTER 2THE FOSSIL FUELS

  2. 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 sun’s 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 earth’s 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 1859 1980s US Oil - Then and now “Colonel” Drake at first oil well in Titusville Pennsylvania Modern US oil refinery

  9. 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.

  10. 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

  11. Kessler Royal Dutch Oil Samuel Shell Oil D’Arcy British Petroleum Other Early Oil Barons

  12. 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

  13. 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

  14. 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 ... 8 Larger view Next slide

  15. US Oil Production Decline Estimated oil remaining 56 years at 2x109 bbl/yr

  16. 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

  17. 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

  18. 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

  19. 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 400°C, 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:

  20. Decreasing Temperature 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.

  21. 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).

  22. Oil Refining (4) CnH2n+2 • 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

  23. Burning off gas Refinery A Modern Oil Refinery

  24. 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

  25. DOE Annual Energy Review 1999 Petroleum consumption by sector

  26. Another Fuel Crisis ? • Last Fall Headlines • Europe Fuel Protests Grow, Pumps Run Dry • Tuesday September 12 9:12 AM ET • Blair convenes crisis talks to calm fuel frenzy • Tuesday September 12, 12:44 PM • Fuel protest to bring London to standstill-farmers • Tuesday September 12, 12:25 PM • Pumps run dry amid fuel protest chaos • September 11, 2000 • Fuel protest spreads across Europe • September 11, 2000

  27. Deja Vu European Fuel Shortage 2000

  28. 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

  29. 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

  30. Natural Gas Usage • Note the trend to use more than is produced • Imports from Canada by pipeline and Algeria by cryogenic hold ships

  31. Users of Natural Gas in USA

  32. Natural Gas Pipe Grid Fundamentals of the Petroleum Industry Robert O. Anderson, 1984

  33. 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

  34. Coal Extraction Open cast mining Underground Mine Mine tour

  35. 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

  36. Coal End Users (1950-2000)

  37. 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

  38. 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.

  39. 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 8

  40. 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 ...

  41. 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

  42. 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 (>80%) • 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 1970’s • 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. 8

  43. 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.

  44. 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

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