Geologic Resources: Nonrenewable Mineral and

Energy Resources

Nature and Formation of Mineral Resources

• Mineral resource: concentration of naturally occurring material in or on the earth’s crust that can be extracted at an affordable cost; nonrenewable resource

• Mineral resources• Metallic: Fe, Cu, Al• Non-metallic: salt, clay, sand, phosphates, soil• Energy resources: coal, oil, natural gas, & U• Magma• Hydrothermal • Weathering

Categories of Nonrenewable Mineral Resources

• Identified resources: deposits of a nonrenewable mineral resource with a known location, quantity, and quality based on geological evidence and measurements

• Undiscovered resources: potential supplies of a nonrenewable mineral resource assumed to exist but having unknown specific information

• Reserves: identified resources mineral can be extracted

• Other resources: identified and undiscovered not classified as reserves

Existence

Decreasing certainty Known

De

crea

sin

g c

ost

of e

xtra

ctio

n

Otherresources

Reserves

Undiscovered Identified

No

t eco

no

mic

al

Eco

no

mic

al

Fig. 14.2, p. 321

General Classification of Mineral Resources

Ore formation• Magma: wells up into earth’s crust at divergent

and convergent plate boundaries• Hydrothermal process: sea floor spreading allows

magma to upwell; seawater dissolves metals from rock or magma; as solutions cool, their dissolved minerals cool and form deposits

• Hydrothermal also includes hydrothermal vents and manganese nodules on the Pacific Ocean floor; may have formed from hot solutions rising from volcanic activity

• Weathering: sedimentary sorting and precipitation-placer deposits also evaporite mineral deposits

• Weathering by water-residual deposits of metal ores in soil

Magma

Black smoker

Sulfidedeposit

White crab White clam

Tube worms

Whitesmoker

Fig. 14.3, p. 322

Hydrothermal Vents

Finding Nonrenewable Mineral Resources

Finding Nonrenewable Mineral Resources

• Satellite imagery

• Aerial sensors (magnetometers)

• Gravity differences

• Core sampling

• Sensors to detect electrical resistance or radiation

• Seismic surveys

• Chemical analysis of water and plants (to detect leaching ores)

Removing Nonrenewable Mineral Resources

• Surface mining

• Overburden (material lying over deposit)

• Spoil (waste)

• Open-pit

• Dredging

• Strip mining (spoil banks)

• Mountaintop removal (spoil allowed by Bush to be dumped in valleys and streams)

• Subsurface mining

• Room and pillar

• longwall

Surface Mining Control and Reclamation Act of 1977

• Surface mined land not restored in many countries

• Requires mining companies to restore most surface mined land so it can be used for the same purpose as it was before it was mined

• Levied a tax on mining companies to restore land that was disturbed by surface mining before the law was passed

Subsurface Mining• Disturbs less land than surface mining• Usually produces less waste material• Not as effective• Expensive and dangerous• Collapse of roofs and walls, explosions of dust

and natural gas, lung diseases• Mine shafts and tunnels• Room and pillars: pillars of ore are left holding up

roof• Longwall: shear off ore, move roof supports and

allow roof to collapse (subsidence of layers on top)

Fig. 14.4a, p. 324

Open Pit Mine

Fig. 14.4b, p. 324

Dredging

Fig. 14.4c, p. 324

Area Strip Mining

Brisbee Strip Mine, AZ

Contour Strip Mining

Mountain top removal

Fig. 14.5a, p. 325

Australian Underground Coal Mine

                                             

  

Room and pillar

Fig. 14.5c, p. 325

Longwall Mining of Coal

Coal Mining

• Long shear wall cut

Anthracite Coal in PA

• 7 billion extractable tons of coal in Eastern Pennsylvania

Anthracite Coal – Llewellyn, PA

• 200 feet below the surface the Salem Coal Vein

runs 70 feet high and 200 feet wide for

about 10 miles.

Coal in Pennsylvania

• Power Operating mine site, Centre Co.

Environmental Impacts of Using Mineral Resources

• Scarring and disruption of the land surface

• Collapse or subsidence of land above (unsettle houses, break sewer, gas, and water lines)

• Wind/water erosion of toxin laced mining wastes

• ACID mine drainage-sulfuric acid produced by aerobic bacteria feeding on iron sulfide

• Emission of toxic chemicals into the atmosphere

• Exposure of wildlife to toxic mining wastes stored in holding ponds and leakage of toxic wastes

AMD: Acid Mine Drainage• Acid mine drainage, sometimes referred to as AMD, results

when the mineral pyrite (FeS2) is exposed to air and water, resulting in the formation of sulfuric acid and iron hydroxide

• For chemists, the equation for AMD formation is:

• FeS2 + 3.75 O2 + 3.5 H2O Fe(OH)3 + 2 H2SO4

• acidity and iron, can devastate water resources by lowering the pH and

• coating stream bottoms with iron hydroxide, forming an orange color

Steps Environmental Effects

exploration, extraction

Mining Disturbed land; mining accidents;health hazards; mine waste dumping;oil spills and blowouts; noise;ugliness; heat

Solid wastes; radioactive material;air, water, and soil pollution;

noise; safety and healthhazards; ugliness; heat

Processing

transportation, purification,manufacturing

Use

transportation or transmissionto individual user,

eventual use, and discarding

Noise; uglinessthermal water pollution;

pollution of air, water, and soil;solid and radioactive wastes;

safety and health hazards; heat

Fig. 14.6, p. 326

Environmental Effects of Extracting Mineral Resources

Percolation to groundwater

Leaching of toxic metalsand other compounds

from mine spoil

Acid drainage fromreaction of mineralor ore with water

Spoil banks

Runoff ofsediment

Surface MineSubsurfaceMine Opening

Leaching may carryacids into soil andgroundwater

supplies

Fig. 14.7, p. 326

Pollution and degradation due to mining

Environmental Effects of Processing Mineral Resources

Environmental Effects of Processing Mineral Resources

• Ore mineral• Gangue-waste material mixed in ores• Tailings-removing the gangue from ores produces

piles of waste• Smelting-used to separate the metal from the other

elements in the ores (emit tons of air and water pollution)

• Mining uses a lot energy, produces a lot of wastes, and the products after used become wastes

Fig. 14.7, p. 326

Surface mining

Metal ore

Separationof ore fromgangue

Scattered in environment

Recycling

Discarding of product

Conversion to product

Melting metalSmelting

Fig. 14.8, p. 327

Life Cycle of Mineral Resource

Carrying Capacity for Geologic Resources

• Exhaustion of the resource or • Environmental damage caused by

extraction, processing, and conversion to products

• Mining industry uses 5-10% of global energy use

• Major contributor to air and water pollution (greenhouse gases)

Grade

• grade: percentage of metal content of an ore

• More accessible and higher grade ores extracted first

• Extracting less accessible and lower grade will lead to greater environmental impacts

• Takes about 75,000 tons to extract about 4.5 lbs gold

• Cyanide heap leaching

KLOOF GOLD MINE, SOUTH AFRICA

The Kloof gold mine lies approximately 60km south west of Johannesburg and 20km from Carletonville, on the border of Hauteng and Northwesdt Provinces, South Africa. Wholly owned by Goldfields Ltd, it consists of three sections, Kloof, Libanon and Leeudoorn, which were amalgamated into one operating division during 2001/02. The mine operates at depths of 1,000m to 3,500m and employs 16,100 people.

Gold found in Sedimentary Rocks

Kloof lies in the 'West Wits' goldfield, part of the Archaean-age Witwatersrand Basin, between the north-trending Witpoortjie Fault to the east and the Bank Fault to the west. The basin itself consists of a 6km thickness of argillaceous and arenaceous sedimentary rocks within the Kaapvaal Craton. Gold mineralisation is found in quartz pebble conglomerate reefs, the gold generally occurring in native form with pyrite and carbon. Kloof is the highest-grade gold mine in South Africa.

Ore at West Wits FieldsAs of mid-2002, Kloof's ore reserve and resources inventory was:

•Underground •Proved: 25.2Mt grading 10.5g/t gold •Probable: 58.8Mt at 11.0g/t gold •Total underground: 84.0Mt at 11.0g/t gold, containing 29.3Moz •Surface •Probable: 31.9Mt grading 0.6g/t gold, containing 0.6Moz •Total: 115.9Mt grading 8.1g/t, containing 29.9Moz of gold

Kloof Production• Production for the past three financial years:

2006 2007 2008

Ore milled (Mt)

3,666 3,829 3.953

Gold yield g/ton

7.8 7.5 6.5

Gold produced (Moz)

914 923 821

Cash cost US$/oz

430

Economic Depletion of a nonrenewable resource

• Costs more to find, extract, transport,and process the remaining deposit than it is worth

• then,: recycle, reuse, waste less, use less, find a substitute, or do without

Supplies of Mineral ResourcesSupplies of Mineral Resources• Economic depletion

• Depletion time (time it takes to use 80%)

• Reserve to production ratio (# yrs use up reserve at current use rate)

• Foreign sources

• Economics

• Environmental resources

• Mining the ocean

• Finding substitutesFig. 14.9, p. 329

Refer to Fig. 14-10 p. 329

Present Depletiontime A

Depletiontime B

Depletiontime C

Time

Pro

du

ctio

n

C

B

A

Recycle, reuse, reduceconsumption; increasereserves by improvedmining technology,higher prices, andnew discoveries

Recycle; increase reservesby improved miningtechnology, higher prices,and new discoveries

Mine, use, throw away;no new discoveries;rising prices

Fig. 14.9, p. 329

Depletion Curves of mineral resources

Free Market vs Government/Industry

• Free market price goes up then: exploration, better mining technology, lower grades become profitable, research for substitutes, & conservation

• If govt. and industry control supply, demand, and price then a competitive market doesn’t exist

• Our govt subsidizes exploration and depletion• Incentives for wise dev and use or cheap

prices?

General Mining Law of 1872• Designed to encourage mineral exploration and

develop west• Person can assume legal ownership of land on

all U.S. public land except parks and wilderness by patenting it

• To get patent: declare there are minerals, spend $500 improve land, file claim, pay annual fee of $ 100/20 acres, pay $2.5-$5/acre for land

• Purchased land may be used, leased, or sold for any purpose

• Purchaser may be domestic or foreign interest

Provisions of Mining Law 1872

• Hardrock mining companies pay no royalties (oil and gas pay 12.5% and coal pays 8-12.5%)

• No provisions for any environmental clean up

Mining Companies vs Environmentalists

• Cost +$100 million to develop

• Provide jobs• Supply resources for

industry• Stimulate national and

local economies• Reduce trade deficits• Same American

consumers money• 1 in 10,000 new sites will

become producing mine

• Permanently banning sale of land; give 20 yr lease

• Require mining companies to pay 8-12% royalty

• Mining companies legally and financially responsible for clean up

• Actual cost of mining small part of product

Developing Public Lands or Extracting Minerals from Lower Grade Ores?

• Public lands are mostly in Alaska & the West

• There are mineral deposits on that land

• Environmentalists & others suggest mining for lower grade ores since extraction and mining technology is greatly improved

• 1900 Cu ore 5% by mass; now 0.5% and costs less due to better technology

Uranite• Coarse botryoidal

uraninite

• carbonate gangue shows bireflectance (top left)

• Uranium is a very dense, radioactive metallic element, naturally occurring in most rocks, soil, in the ocean. It is not rare, and in fact occurs more commonly than gold, silver or mercury.

Magnetite, iron, haematite and limonite. Scotland

• A magnetic separate in which angular magnetite (brown grey), a coarse-grained crystal of haematite (blue-grey, centre top left) and limonite (blue-grey, low reflectance, centre bottom left) are natural phases.

Copper Ore

Zircon, native gold, copper and iron. Gold concentrate. Brazil

• Zircon (grey) is accompanied by irregular-shaped high fineness gold (~960) (yellow, high reflectance) grains. Copper metal (pink, high reflectance, centre) and iron (white, high reflectance, top left).

Bauxite: Aluminum Ore

• Found in deeply weather volcanic rocks, usually basalt, form bauxite deposits

• This one is from Australia.

Iron Ore• It almost

always consists of iron oxides, the primary forms of which are magnetite (Fe3O4) and hematite (Fe2O3).

Tilden Iron Ore Mine in Michigan

Tilden Mine

Extraction of Lower Grade Ores

• Better earth removing equipment

• Better techniques for removing impurities

• Limited by quantities of freshwater to mine and process minerals (esp in arid areas)

• Cost prohibitive

• Environmental impact

Mining the Ocean• Sources include seawater, sediments,

hydrothermal vents, and Mn nodules

• Seawater too diffuse for most: currently extract Mg, Br, and NaCl

• Sand, gravel, phosphates, S, Sn, Cu, Fe, W, Ag, Ti, Pt, and diamonds in sea floor deposits on continental shelf

• Deep ocean floor: Au, Ag, Zn, Cu are found as sulfide deposits at hydrothermal vents and Mn nodules-too expensive to mine

Mining the Ocean

Microbe Mining

• Environmentally safer: reduce air and water pollution

• Wells drilled into ores to fracture deposit• Inoculated with natural or genetically

engineered bacteria to extract desired metal• Well flooded w water and pumped to surface • Metal removed• 30% of Cu mined with microbes• Drawback is it is slow-decades not months

Microbe Mining• Science 264 (1994), 778-9. proving cheaper and

enabling the extraction of metals from low grade ores. It has been used for copper, and is also being used for gold and phosphate.

• GEN (1 Nov 1993), 1, 21. A bacterial system to remove heavy metals including radioactive compounds from water is being promoted by a British company; The Citrobacter species have been tested on uranium, and act by a combination of bio-accumulation (metals accumulate inside cells, which are resistant to their toxic effects) and biosorption (metals stick to cell surfaces).

Substitutes• Ceramics and plastics can be used in place of

metals

• Cost less to produce (less energy), don’t require painting, can be molded, don’t oxidize

• No substitutes for He, phosphorus for phosphate fertilizers, Mn for steel production, and Cu for wiring

• Substitutes not viable if require more energy to produce or if they are inferior to the materials they replace

Important Nonrenewable Energy Sources

Oil drillingplatformon legs

Mined coal

Pipeline

Pump

Oil well

Gas well

Oil storage

CoalCoalOil and Natural GasOil and Natural Gas Geothermal EnergyGeothermal Energy

Hot waterstorage

Contourstrip mining

PipelineDrillingtower

Magma

Hot rock

Natural gasOil

Impervious rock

Water Water

Floating oil drillingplatform

Valves

Undergroundcoal mine

Water is heatedand brought upas dry steam or

wet steam

Waterpenetratesdownthroughtherock

Area stripmining

Geothermalpower plant

Coal seam

Fig. 14.11, p. 332

Fig. 14.10, p. 329

Locating Oil: Geophysical Method

• Early oil explorers used basic tools that depend on variable’s in the earth’s physical condition such as;

• Gravity change, magnetic field change, time change, and electrical resistance.

• The most common tool used is the torsion balance.

Typical seismic surveying

The Torsion Balance

• It was designed by Baron

von Eoetvoes of Hungary.

• The torsion balance makes use of the earth’s gravitational field and can detect variations in mass distribution near the earth’s surface.

First Torsion Balance Discovery

• Oil can be found in low gravity areas because the rocks that surround oil are not dense.

• The first oil discovery using this method was in Brazoria County, Texas, in 1924.

•

The Pendulum Balance

• E. A. Eckhardt and R. D. Wycoff invented the Pendulum Balance in 1930.

• It was used to detect the presence of oil in Liberty County, Texas.

How does it work?

• The pendulum method relies on the measure of the period of oscillation in a given area.

• The pendulum’s oscillation is adjusted by variations in gravitational force due to changes in altitude and latitude.

The gravity meter

• The gravity meter or gravimeter measures variations in the earth’s gravitational force without any calculations.

• They were invented as early as 1899, but were not proven until the discovery of the Tom O’Conner field in south Texas in 1934.

• The gravity meter is also used in marine and airborne exploration.

Magnetic Method

• Most oil is found in sedimentary rocks which are not magnetic.

• Igneous and metamorphic rock rarely contain oil but are highly magnetic.

• By conducting a magnetic survey over a given area a prospector can determine where oil is more likely to be found.

Satellites (8)

Magneto Meter (11) and Radar (9)

Compressed Air Guns (13)

Geophones (14)

Sniffer (15)

A sniffer can detect traces of gaseous hydrocarbons escaping from the earth’s subsurface.

Preparing to Drill

• Must be surveyed to determine its boundaries• Environmental impact studies• Lease agreements, titles and right-of way accesses

for the land • The land is cleared and leveled, and access roads

may be built • Because water is used in drilling, there must be a

source of water nearby. If there is no natural source, they drill a water well.

Preparing to Drill (continued)

• Dig a reserve pit-used to dispose of rock cuttings and drilling mud during the drilling process, and line it with plastic to protect the environment.

• Ecology sensitive must be disposed offsite instead of placed in a pit.

Cable-Tool Drilling

Rotary Drilling

Testing After Drilling

• Well logging - lowering electrical and gas sensors into the hole to take measurements of the rock formations there

• Drill-stem testing - lowering a device into the hole to measure the pressures, which will reveal whether reservoir rock has been reached

• Core samples - taking samples of rock to look for characteristics of reservoir rock

Natural gas extraction becomes more challenging

• The first gas fields simply required an opening and the gas moved upward

• Most remaining fields require pumping by horsehead pumps

• Most accessible reserves have been depleted

– Gas is accessed by sophisticated techniques such as fracturing, which pumps high-pressure salt water into rocks to crack them

“Fracking” natural gas• Used for over 60 years to stimulate gas and oil wells

• estimated 90% of the natural gas wells in the US use hydraulic fracturing to produce gas at economic rates

• Hydraulic fracture of the rock may be natural or man made

• The fracture is extended by pumping in extracted by pumping 1-5 million gallons of water plus hydrofracturing chemicals down a gas well

• The fracture is filled with proppant-inert material to keep the fracture open for example sand or ceramic pellets

• Drilling by the well bore is vertical and then horizontal and drilled 1-3 miles down where there is insufficient porosity for the oil, gas, or water to flow freely

• Drilling is in unconventional areas-oil shale, tight gas, and coal seam gas can be fractured to yield oil and gas

“Fracking” and oil wells use large quantities of water

Water in fracking• The need for water often exceeds what is available locally, so

water is pumped and trucked in from other areas

• Following use, much of that water can’t be recovered

• The water that is recovered contains fracturing chemicals, sand, or other proppants –it isn’t suitable to reintroduce to ground water or reservoirs, even after salts are concentrated and removed

• Water is usually pumped in deep wells dug for that purpose

• Contamination by the water is a major ecological and human health problem.

Offshore drilling produces much of our gas

• Drilling takes place on land and in the seafloor on the continental shelves

– Technology had to come up with ways to withstand wind, waves, and currents

– Platforms are either strong fixed platforms or floating platforms

– 25% of our natural gas comes from offshore drilling

– Hurricanes can devastate drilling platforms, and prices rise accordingly

We drill to extract oil

• Exploratory drilling = small, deep holes to determine whether extraction should be done

• Oil is under pressure and often rises to the surface

– Primary extraction = the initial drilling and pumping of available oil

– Secondary extraction = solvents, water, or stream is used to remove additional oil; expensive

– We lack the technology to remove every bit of oil

– As prices rise, it becomes economical to reopen a well

Primary and secondary oil extraction

Primitive

Hunter–gatherer

Earlyagricultural

Advancedagricultural

Earlyindustrial

Modern industrial(other developed

nations)

Modern industrial(United States)

Society Kilocalories per Person per Day

260,000

130,000

60,000

20,000

12,000

5,000

2,000 Fig. 14.12, p. 333

Cultural changes and technologicalAdvances have increased energy use per person

Current Use of Commercial Energy

• Use of coal is declining because it is the most polluting of the fossil fuels

• Use of oil continues to increase by 1%/yr• Natural gas in increasing by 2% /yr• Production of electricity by nuclear power

will be phased out due to reductions of government subsidies

• Developing countries are still burning wood

World

NaturalGas23%

Coal22%

Biomass12%

Oil30%

Nuclear power6% Hydropower, geothermal,

Solar, wind7%

Fig. 14.13a, p. 333

Commercial Energy use for World

United States

Oil40%

Coal22%

NaturalGas22%

Nuclear power7% Hydropower

geothermal, solar, wind

5%

Biomass4%

Fig. 14.13b, p. 333

Commercial Energy Use of US

Year

210020251950187518000

20

40

60

80

100C

ontr

ibut

ion

to t

otal

ene

rgy

cons

umpt

ion

(per

cent

)Wood

Coal

Oil

Nuclear

HydrogenSolar

Natural gas

Fig. 14.14, p. 334

Commercial Energy Use in US

Evaluating Energy Resources

• Renewable energy

• Nonrenewable energy

• Future availability

• Net energy yield

• Cost

• Environmental effects

Net Energy• Each time high quality energy is used, even

to make more high quality energy, some of the energy will be degraded

• Net energy is the total amount of energy available from an energy resource after subtracting the energy used to find, extract, process, & transport the energy to the users

• It can be expressed as a ratio of total energy available from the resource and the amount energy used to make it available

Diesel oil

Asphalt

Greaseand wax

Naphtha

Heating oil

Aviation fuel

Gasoline

Gases

Furnace

Heatedcrude oil

Refining Crude Oil

• Petroleum (crude oil)

• Primary Recovery

• Secondary Recovery

• Tertiary Recovery

• Petrochemicals

• Refining

North American Energy Resources

CoalCoal

GasGas

OilOil

High potentialHigh potentialareasareas

MEXICO

UNITED STATES

CANADA

PacificOcean

AtlanticOcean

GrandBanks

Gulf ofAlaska

Valdez

ALASKABeaufort

Sea

Prudhoe Bay

ArcticOcean

PrinceWilliam Sound

Arctic National Wildlife Refuge

Trans Alaskaoil pipeline

Fig. 14.17, p. 338

Oil Production

• By 1996, there were 1,047,200,000,000 reserve barrels of crude oil.

• Oil Production is predicted to continue rising for the next 30 years.

• 77% of these reserves were produced by countries in OPEC, Organization of Petroleum Exporting Countries

Oil Production

• Top Producers…– Saudi Arabia: 8,100,000 barrels/day– Russia: 6,900,000 barrels/day– USA: 6,500,000 barrels/day– Iran: 3,600,000 barrels/day– China: 3,200,000 barrels/day

Oil Consumption

• The world’s top consumer of oil is the United States.

• Everyday, the U.S. uses 18,830,000 barrels of oil. (2011)

• On average…87,356,000 barrels of oil are used everyday on a global scale. (2011)

Oil Consumption

• OPEC predicts that by the year 2020, daily oil consumption globally will reach 100,000,000 barrels/day.

• For comparison…42 gallons make up one barrel of oil. A milk jug is one gallon.

Seven Sisters

Oil transportation and distribution began with these seven major oil multinationals which

dominate the industry

THEN

NOW

(acquired Amoco &Arco)

+

+

Supply &Demand

• 3 billion tons of oil produced annually

• Seven Sisters control demand– Production &Distribution systems

• Refineries

• Storage facilities

• Distribution centers

• Supply chains &gas stations

Where do they drill oil?• The Seven Sisters invest in infrastructures in:

– Middle East (64%)• Gwahar Field• Iran, Iraq• Saudi Arabia (25%)

– Latin America– Mexico &other developing countries

• Nationalization

– Southwest Asia (Indonesia)– Baku in Azerbaijan

Transportation Between Oil Sites &Refineries

• 5 to 10% of cost

Refineries

• Operate to capacity– Costs 14 cents per gallon

• Sell every drop– Yet insufficient amounts of

refined oil leads to high prices

• No new refineries since 1976– Pollution

– Extravagant cost

– Inefficient

Refineries

• Fewer refineries = Advantage to oil companies

• Mergers give few companies control of market– ExxonMobil profits

jumped 38.8%

Oil Shale and Tar Sands

• Oil Shale

• Keragen

• Tar Sands

• Bitumen

Fig. 14.23, p. 341

Above Ground

Conveyor

Conveyor

Spent shale

Pipeline

Retort

Mined oil shale

Aircompressors

Shale oilstorage

Impuritiesremoved

Hydrogenadded

Crude oil Refinery

AirAirinjectioninjection

Shale layerShale layer

UndergroundUnderground

Sulfur and nitrogencompounds

Shale oil pumped to surfaceShale oil pumped to surface

Shale heated to vaporized kerogen, which is condensed to provide Shale heated to vaporized kerogen, which is condensed to provide shale oilshale oil

Year

1950 1960 1970 1980 1990 2000 20100

10

20

30

40

50

60

70O

il pr

ice

per

barr

el (

$)

(1997 dollars)

Fig. 14.18, p. 339

Inflation Adjusted Price of Oil

World

Year1900 1925 1950 1975 2000 2025 2050 2075 21000

10

20

30

40A

nnua

l pro

duct

ion

(x 1

09 ba

rrel

s pe

r ye

ar)

2,000 x 109

barrels total

Fig. 14.19a, p. 339

Production Curve World

United StatesYear

1900 1920 1940 1960 2080 2000 2020 20400

1

2

3

4A

nnua

l pro

duct

ion

(x 1

09 ba

rrel

s pe

r ye

ar)

Proven reserves:34 x 109

barrels

200 x 109

barrels total 1975

Undiscovered:32 x 109

barrels

Fig. 14.19b, p. 339

Petroleum Production in US

Nuclear power

Natural gas

Oil

Coal

Synthetic oil andgas produced

from coal

Coal-firedelectricity

17%

58%

86%

100%

150%

286%

CO2 emissions per unit of energy as expressed in % of emissions produced by coal

Low land use

Easily transportedwithin and between countries

High netenergy yield

Low cost (withhuge subsidies)

Ample supply for42–93 years

Advantages

Moderate waterpollution

Releases CO2 when burned

Air pollutionwhen burned

Artificially low price encourageswaste and discourages search for alternatives

Need to findsubstitute within50 years

Disadvantages

Fig. 14.21, p. 340

Fig. 14.22, p. 340

Using Heavy Oils from Oil Shale and Tar Sand as Energy Resources

• Advantages• Moderate existing

supplies• Large potential

supplies

• Disadvantages• High costs• Low net energy yield• Large amount of water

needed to process• Severe land disruption

from surface mining• Water pollution from

mining residues• Air pollution when

burned• CO2 emissions when

burned

Above Ground

Conveyor

Conveyor

Spent shale

Pipeline

Retort

Mined oil shale

Aircompressors

Shale oilstorage

Impuritiesremoved

Hydrogenadded

Crude oil Refinery

Airinjection

Shale layer

Underground

Shale heated to vaporized kerogen, which is condensed to provide shale oil

Sulfur and nitrogencompounds

Fig. 14.23, p. 341

Shale oil pumped to surface

Hydrogenadded

Impuritiesremoved

Syntheticcrude oil

Refinery

Pipeline

Tar sand is mined. Tar sand is heateduntil bitumen floats

to the top.

Bitumen vaporIs cooled andcondensed.

Fig. 14.24, p. 341

Natural Gas

• 50-90% methane

• Conventional gas

• Unconventional gas

• Methane hydrate

• Liquefied Petroleum Gas (LLPG)

• Liquefied Natural Gas (LNG)

• Approximately 200 year supply

Composition of Natural Gas

• 50-90% by volume of methane

• Smaller amounts of heavier gaseous hydrocarbons such as ethane, propane, and butane

• Small amounts of hydrogen sulfide

Where is natural gas found?

• Conventional natural gas found above oil deposits

• Unconventional natural gas found by itself

• Methane hydrate is a gas trapped in ice crystals deep beneath the arctic permafrost and beneath deep ocean sediments

• most is in Russia and Kazakhstan (42%)

Liquefied petroleum gas (LPG)

• Propane and butane gases are liquefied and removed as LPG

• Stored in pressurized tanks for use in rural areas not served by natural gas pipelines

Liquefied Natural Gas (LNG)

• LPG is dried to remove water vapor and methane is removed and hydrogen sulfide removed

• LNG is then pumped into pressurized pipelines for distribution

• Kept refrigerated at -184C (-300F)

Coal

• Stages of coal formation• Primarily strip-mined• Used mostly for generating

electricity• Enough coal for about 1000 years• Highest environmental impact• Coal gasification and liquefaction

Coal FormationCoal FormationFig. 14-27 p. 344Fig. 14-27 p. 344

Coal Supplies

• Coal provides ~21% of world’s commercial energy

• It is used to generate electricity and make steel

• ~66% of coal is in US (much anthracite PA)

• Coal is most abundant fossil fuel

• Identified sources at current rates about 200 years and unidentified at current rates about 1000 years; when consumption rates go up, estimated coal sources will last about 200 years

Coal Mining and Consumption has Greatest Environmental Impacts of all Fossil Fuels

• Land disturbance

• Air pollution

• CO2 emissions

• Release of particles of Hg

• Release of radioactive particles

• Water pollution

• Health and property damage

Burning Coal More Efficiently

• Fluidized bed combustion

• Coal gasification:converts coal into synthetic natural gas (SNG)

Calcium sulfateand ash

Air

Air nozzles

Water

Fluidized bed

Steam

Flue gases

Coal Limestone

Fig. 14.29, p. 345

Raw coal

Pulverizer

Air oroxygen

Steam

Pulverized coalSlag removal

Recycle unreactedcarbon (char)

Raw gases CleanMethane gas

Recoversulfur

Methane(natural gas)

2CCoal

+ O2 2CO

CO + 3H2 CH4 + H2O

Remove dust,tar, water, sulfur

Fig. 14.30, p. 345

Fig. 14.26, p. 342

Natural Gas as Energy Resource• Advantages• Ample supplies (125

years)• High net energy yield• Low cost (w

subsidies)• Lower CO2

emissions• Moderate env impact• Easily transported by

pipeline• Low land use• Good fuel for fuel

cells and gas turbines

• Disadvantages• Nonrenewable resource• Releases CO2 when

burned• Methane can leak from

pipelines• Difficult to transfer

from country to country• Shipped across ocean as

highly explosive LNG• Sometimes burned off

and wasted at wells due to low price

• Requires pipelines

Burning Coal More Cleanly

• Fluidized Bed combustion

Calcium sulfateand ash

Air

Air nozzles

Water

Fluidized bed

Steam

Flue gases

Coal Limestone

Fig. 14.29, p. 345

Fluidized Bed Combustion• Sorbent, limestone or dolomite, captures sulfur

released by coal combustion

• Jets of air suspend the mixture of sorbent and burning coal during combustion

• The red hot particles flow like a fluid

• Elevated pressure and temperatures produce a high pressure gas stream that can drive a turbine

• Steam generated can drive a steam turbine• http://www.netl.doe.gov/publications/factsheets/program/prog031.pdf

Raw coal

Pulverizer

Air oroxygen

Steam

Pulverized coal

Slag removal

Recycle unreactedcarbon (char)

Raw gases Clean CH4gas

Recoversulfur

Remove dust,tar, water, sulfur

Fig. 14.30, p. 345

CO + 3H2CH4 + H2O

2C(coal) + O2 2CO

Coal Gasification

Coal Gasification• Coal/water slurry and oxygen are reacted at high

temperature and pressure to produce syngas (SNG)

• Ash flows out of the bottom into a water filled sump where it becomes solid slag

• The syngas moves from the gasifier to a radiant syngas cooler which generates high pressure steam

• Then the syngas is scrubbed of particles and sulfur

• The gas can then be used to power a gas turbine• http://www.lanl.gov/projects/cctc/factsheets/tampa/tampaedemo.html

Using Coal as Energy Source• Advantages

• Ample supplies (225-900 yrs)

• High net energy yield

• Low cost with huge subsidies

• Disadvantages• Very high environmental

impact• Severe land disturbance, air

pollution, and water pollution

• High land use including mining

• Severe threat to human health

• High CO2 emissions when burned

• Releases radioactive particles and Hg into air

Syngas as Energy Source

• Advantages• Large potential• Supply• Vehicle fuel• Moderate cost (w lg

govt subsidies)• Lower air pollution

when burned than coal

• Disadvantages• Low to moderate

net energy yield• Higher cost than

coal• High

environmental impact

• Increased surface mining of coal

• High water use• Higher CO2 • emissions than

coal

Source of Energy in Nuclear Fission Reactor

• Neutrons split the nuclei of atoms like U 235 and Pt 239

• U and Pt are ores that are mined