ENERGY AND RESOURCES

Chapters 23, 19, 20, 21

Minerals and Mining

CHAPTER 23

MINERAL RESOURCES

Rocks provide the minerals we use Rocks are a solid aggregation of minerals Minerals are naturally occurring solid chemical elements or compounds

Mining is used to obtain minerals Fossil fuels, groundwater?? Most minerals are in low concentrations, so scientists attempt to find

concentrated sources of minerals before mining begins Metals can be extracted within ore

Metals are elements that are typically lustrous, opaque, malleable conductors Most metals are not found in a pure state, but are found within an ore (a

grouping of minerals) Common economically valuable metals: copper, iron, gold, aluminum

Metals need to be processed to separate them from the ore and make them ready for use

Chemical or physical removal Smelting Harmful byproducts?

Tailings

MINERAL RESOURCES

We also mine/use many non-minerals Construction Materials: Sand, gravel, Fertilizers: phosphates, Other economic value: limestone, salt, potash,

diamonds Fuels: Uranium, Fuels that are not technically minerals: coal,

petroleum, natural gas, oil sands, oil shale, methane

Conflict over mining products “blood diamonds”

MINING METHODS

Mining makes a huge contribution to the economy $57 B in raw materials (2009) $454 B in processed materials (2009) 1.2 million jobs

Mining exerts a huge impact on the environment! Strip mining Subsurface mining Open Pit mining Placer mining Mountaintop mining Solution mining Ocean mining

https://www.youtube.com/watch?v=ioqauAoZwVY

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

TYPES OF MINING (DESCRIPTIONS AND IMPACTS)

CAN MINING IMPACTS BE REGULATED OR REVERSED?

Mining companies are required to restore sites when finished (in the United States) Reclamation

Removal of buildings and structures Soils: biotic potential? Waters: drainage and reclamation

Policies General Mining Act of 1872 Hardrock Mining and Reclamation Act of

2009 Mineral Leasing Act of 1920

SUSTAINABLE MINERAL USE

Non-renewable resource in limited supply Economically recoverable mining Technically recoverable mining

How long will deposits last? Discovery of new reserves New extraction technologies Changing pressures from society, technology, and

consumers Recycling

Gold versus Platinum E-waste

THERE’S NO TOMORROW

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http://www.youtube.com/watch?v=VOMWzjrRiBg0:00-7:10 Introduction

Fossil Fuels, Their Impacts, and Energy Conservation

CHAPTER 19

SOURCES OF ENERGY Since the Industrial Revolution, our main source of energy has been:

Sun Photosynthesis Fossil Fuels

Fossil Fuels (Coal, Oil, Natural Gas) High energy content allows for

Shipping Burning Storing

Used for Transportation Heating/Cooking Electricity (secondary form of energy that can be transported over long distances)

Others Geothermal Tides Nuclear Energy Biomass Solar, Wind

GRAPH THE GLOBAL CONSUMPTION OF FOSSIL FUELS OVER THE PAST 50 YEARS

FOSSIL FUELS Come from fossils Depends upon

Starting material Temperature and pressure Anaerobic decomposers (Aerobic versus Anaerobic decomposition) Time

Because of all these factors, deposits for FF are unevenly distributed Developed Nations consume more than Developing Nations (20% by United States)

Oil• Saudi Arabia (20%)• Venezuela (13%)

Natural Gas• Russia (24%)• Iran (15.8)

Coal• United States (28.9%)• Russia (19%)

IT TAKES ENERGY TO MAKE ENERGY

Net energy expresses the difference between energy returned and energy invested

EROI (Energy Returned on Investment) EROI= Energy returned/Energy invested The higher the EROI ratio, the more energy

we get per unit we invest Oil and natural gas were 100:1 in 1940,

30:1 in 1970 and are about 5:1 now….WHY?

COAL Most abundant fossil fuel Hard, dark substance that form from organic matter

(almost always woody plant matter) that gets compressed under high pressure where little or no decomposition has taken place Starts as peat and them becomes coal Deposition mostly occurred 300-400 million years ago in

swampy environments The high pressure of formation results in a dense, solid carbon

structure Has been used by humans for thousands of years, but

demand began increasing with the start of the steel industry (1875)

Provides 50% of electrical energy in the US China (39%) and US (16%) are the primary producers China (39%) and US (15.5%) are the primary consumers

COAL We extract coal by

Strip mining Subsurface mining Mountaintop removal mining

Types of coal (changes in water, carbon, and energy content) Lignite (least compressed=less carbon=less energy per unit volume) Sub-bituminous Bituminous Anthracite (most compressed=more carbon=more energy per unit volume)

Coal can also vary in its impurities = important for reducing pollution We get energy from coal by

Combusting (burning) coal to convert water to steam which turns a turbine

NATURAL GAS Versatile and clean-burning compared to other

fuels (emits ½ the carbon or coal and 2/3 the carbon of oil)

Consists of methane and other hydrocarbons Uses: heating our homes, electricity At low temps (in a liquid state) it can be

shipped long distances Russia (21%) and US (19%) are the largest

producers US (21%) and Russia (15%) are the largest

consumers At current rates of use, we have about 60 years

left

NATURAL GAS Formation

Biogenic gas: shallow, anaerobic decomposition

swamp gas gas from landfills

Thermogenic gas: deep underground compression

Kerogen: can form natural gas and crude oil, most gas is found above oil or coal

Most commercially extracted gas is thermogenic

Coalbed methane: commonly leaks out during mining processes

Miners now try to trap and use this gas or burn it off (called flaring)

FRACKING

Gas naturally moves upwards because of pressure underground and its low molecular weight

Because we have already mined so much gas, many sites now require gas to be pumped to the surface with a “horsehead pump”

Fracturing techniques (known as “fracking”) break into rock formations using water under high pressure, hold the crack open with sand or glass beads, and extract the gas This process bring up many concerns!

OFFSHORE DRILLING

Natural gas (13%) and oil (1/3) come from the Gulf of Mexico and southern California coast

Drilling into the seafloor on the continental shelf (this is where more of the remaining resources probably are)

Platforms must withstand wind, waves, currents Some actually float

Potential Issues? Moratorium on offshore drilling lifted in

2008 and then expanded in 2010 Deepwater Horizon Backtracking and stoppage of new

approvals

OIL/PETROLEUM

Oil is our most used fuel, accounting for 35% Used since 1854 (Pennsylvania) Crude Oil (a sludgelike liquid) usually forms 1.5-3km

below the surface from dead plant material trapped under marine waters millions of years ago (just like natural gas)

Globally, 200 gallons are used per person Use has increased 15% in the last decade and does not

show signs of slowing (US, China, India) Russia (12%) and Saudi Arabia (12%) are the largest

producers (followed by US at 10%) United States (22%) and China (10%) are the largest

consumers

HOW DO WE GET OIL? Geothermal heating allows crude oil to migrate up through

rock pores and collect in layers Geologists search for oil by drilling, using seismic surveys, and

mapping underground rock formations These methods have estimated that 11.6-31.5 billion barrels of oil

lay beneath the Arctic National Wildlife Refuge, of which 4.3-11.8 are recoverable currently

Proven Recoverable Reserve Technology determines what can be extracted Market Price determines how much will be extracted• Drilling extracts oil• Exploratory Drilling • Primary Extraction: Oil rises on its own

from pressure• Secondary Extraction: 2/3 of oil may

remain trapped, solvents and/or water and steam are used• $$$$$• Not everything can be removed with

our current technology

USES OF OIL Petroleum products

Separation of components of crude oil (based on size of hydrocarbon chains) must take place at a refinery

Heating, cooking, transportation, asphalt, plastics, lubricants, fabrics, pharmaceuticals, fertilizers, pesticides

ARE WE RUNNING OUT OF OIL?

Estimates are that we have used around ½ of the world’s oil reserves Reserves-to-production ratio (R/P ratio)

Total remaining reserves/annual production rate 1.2 trillion barrels/30 billion barrels = 40 more years

When should we start to worry? When we run out “Peak Oil”……now Hubbert’s Peak

Should we worry? Suburbs as slums of the future Conservation of energy and alternative energy

soruces

OIL SANDS (TAR SANDS)

Sand and clay that contain 1-20% bitumen, a thick form of petroleum

Too thick to extract conventionally, so strip mining is often used at the surface

Deposits more than 75m below ground are removed using steam injection or chemical solvents

After extraction, it must be sent to a refinery that can upgrade the fuel by adding hydrogen and removing carbon

¾ of deposits are found in Venezuela and Alberta (may almost as much in Canada as oil in Saudi Arabia)

OIL SHALE Sedimentary rock filled with kerogen (organic matter) that

can be processed to produce liquid petroleum Forms through the same process as oil, but not buried deeply

enough Mined through strip mining or subsurface mines It can be burned like coal or baked to extract liquid petroleum 40% of world reserve is found in US west High fuel prices are attracting people to oil shale

METHANE HYDRATE

Found in sediments on the ocean floor Is stable at these conditions

(temperature/pressure) Formed by anaerobic

decomposition and thermogenic formation below the surface

There are immense amounts available, but we do not know how to extract them safely Release of gas that could cause

landslides/tsumani/global warming

DRAWBACKS OF ALTERNATIVE FUELS

1. Low EROI 2:1 or 3:1 for oil shale 5:1 for crude oil

2. Environmental impacts Strip mining that devastates landscapes Pollution of waterways Non-recovered areas

3. Emissions Carbon dioxide, methane, air pollutants

IMPACTS OF FOSSIL FUELS Pollution

Air: Irritants, carcinogens, asphyxiation, poisons, photochemical smog, bioaccumulation

Water: Mostly non-point source problem, although we usually hear about the point source problems in the news

Exxon Valdez (1989) Cars, homes, industry, gas stations ….. All create runoff that can contaminate

waterways and groundwater (drinking water)

Drive climate change Retired carbon from long-term reservoir underground and release it

into the air Carbon from the fuel combines with oxygen in the air to form Carbon

Dioxide Methane is also a powerful greenhouse gas

Alters the environment Acid drainage from coal mining Road networks Infrastructures

SOLUTIONS? Clean coal technologies

Techniques that aim to remove chemicals during the process of generating electricity from coal

Scrubbers Dry coal Gasification (syngas)

Carbon capture and carbon storage (sequestration) Capturing emissions, converting the gas to a liquid and then

storing it in the ocean or underground in rock Mattoon, Illinois Will it stay underground? Will it trigger earthquakes? Will it contaminate groundwater? Will it acidify the ocean? Will it prolong our dependence on diminishing fossil fuels?

Directional Drilling

ISSUES

Political Issues National can become dependent on foreign energy OPEC (Organization of Petroleum Exporting

Countries) Economic Issues

Supply and prices can change economies of nations Strategic Petroleum Reserve

Social Issues Local people may or may not benefit from reserves

CONVERSION TO RENEWABLE ENERGY?

Option 1: Use it until its gone Option 2: increase funding to develop energy

alternatives to start a rapid shift Option 3: middle group, reduce our dependence

gradually

Energy efficiency: get more and use less Energy conservation: use less

Cars Café Standards (corporate average fuel efficiency standards) Low taxes on gas in US Cash for Clunkers

Personal choice Increased efficiency

Cogeneration

THERE’S NO TOMORROW

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http://www.youtube.com/watch?v=VOMWzjrRiBg7:10-12:01 Oil, Coal, Natural Gas

Conventional Energy Alternatives:Nuclear energy, bioenergy, hydroelectric power

CHAPTER 20

CONVENTIONAL ENERGY ALTERNATIVE Play a minor yet substantial role in

energy and electricity budgets today Fuelwood and Biomass= 10% Nuclear= 6% Hydropower= 2%

Less impact that fossil fuels, but more than renewable alternatives

Growth in use is slower than with fossil fuels

NUCLEAR POWER What’s its reputation?

No air pollution Radioactive waste Accidents

Commonly used in US (20%), France (76%), and Japan

How does it work? Fission (splitting of atoms) releases nuclear energy Energy (heat, light, radiation) is converted into

thermal energy and use to generate electricity Must use large, heavy atoms like uranium-235

(which is not a renewable resource)

NUCLEAR POWER If not controlled, the chain reaction of nuclear fission would

start a positive feedback loop releasing enormous amounts of energy (like an atomic bomb) Nuclear reactors control this reaction inside power plants

Process:-Mining: Only 1% of naturally occurring uranium is U235, so the more common U238 must be processed to be at least 3% U235-Usage: enriched uranium is formed into metallic tubes called fuel rods, moderators and control rods make sure that the reaction takes place at the desired rate-Storage: after enough uranium has decayed, energy generation is no longer adequate, so the fuel rods must be replaced

RISKS AND BENEFITS OF NUCLEAR ENERGYBenefits No air pollution Emissions 4-150 times less than fossil fuel combustion Less chronic health risks and safer work environments Less mining=less damage to landscapesRisks Radioactive waste disposal

Waste will emit radiation for thousands of years Waste used to be dumped into the oceans in barrels, now it is held in

temporary storage at power plants Yucca Mountain

Potential for dangerous accidents Three Mile Island and meltdowns Chernobyl

Overall, growth has slowed, new plants aren’t really being built

NEW IDEAS Breeder reactors

Use U238, which usually goes unused as a waste product 99% of all uranium is U238, so it makes better use of fuel,

makes more power, and produces less waste Can be more dangerous because sodium (rather than

water) is used as a coolant Are more expensive Create plutonium as a byproduct, which can be used in

nuclear weapons Fusion

Same process that drives the sun Forces nuclei of lightweight elements together Difficult to do without very high temps (millions of degrees) Requires more energy input than output at this point (EROI

of less than 1)

BIOENERGY/BIOMASS ENERGY Organic materials derived from living or

recently living organisms contains chemical energy from photosynthesis Wood, charcoal, manure Used widely in the developing world

Renewable with no net release of carbon dioxide, but it is hard to just the renewability of the resource

Biopower can be used in the same way as coal to generate power for electricity, or as a liquid fuel for cars

SOURCES OF BIOENERGY Waste products (mostly burned)

Forestry industry, pulp mills, paper mills Agricultural waste (cornstalks, corn husks) Animal wastes Organic waste from landfills

Bioenergy crops (mostly used for liquid fuels) Fast-growing grasses and trees

Combustion strategies Co-firing Gasification

Scales of production Advantages

Reduction of emissions of some pollutants Resources more evenly spread out

Disadvantages Depriving soil of nutrients

ETHANOL AND BIODIESEL IN CARSEthanol Ethanol is produced from fermentation and is added to gas to reduce

emissions (any car can run on up to 10% ethanol) 1990 Clean Air Act Flex-fuel vehicles

This may not be a sustainable energy choice Overuse of land to grow crops Competition with food production drives up food prices Low EROI 1.5:1

Biodiesel Produced from vegetable oils, used cooking grease, or animal fat Fat is mixed with small amounts of ethanol or methanol in the

presences of a catalyst Diesel engines can run on 100% biodiesel, but a 20% mix is more

common Lower emissions and competitive prices Biotour Some environmental impacts from growing these crops

NEW BIOFUELS AND NEW IDEAS Algae/pond scum

Carbon capture potential Cellulosic ethanol

No food value, but abundant in all plants Switchgrass (EROI 5:1)

Is bioenergy carbon-neutral? In theory yes! But what if we burn forests to plant crops? What is we use fossil fuels to generate the

biofuel?

HYDROELECTRIC POWER/HYDROPOWER Kinetic energy of moving water turns turbines

and generates electricity 2 approaches

Storage techniques: Catching water in reservoirs like dams

Run-of-River approach: sacrifices reliability of water flow, but minimizes impacts of large dams

Accounts for 2.2% of worlds energy supply, 16% of electricity production

Dam building began in earnest in the 1930’s and peaked in the 1960’s

BENEFITS AND DRAWBACKSAdvantages Renewable No carbon emissions (except for those released in the

construction of the dam) High EROI of 10:1Disadvantages Destruction of habitats and flow of natural water cycle Suppresses flood plains Thermal pollution Geologic impacts from weight of water

It is unlikely that we will see much more expansion because most of the rivers are already being used

THERE’S NO TOMORROW

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http://www.youtube.com/watch?v=VOMWzjrRiBg12:07-17:15 Energy Alternatives

New Renewable Energy Alternatives:Solar, Wind, Geothermal, Ocean, Hydrogen

CHAPTER 21

NEW RENEWABLESWhy are they considered new?1. They are not used on a wide scale (less than 1% today)2. The technology is still being developed 3. They will likely play a large role in the futureAll can provide energy for:

electricity Heating of air and water Fuel for vehicles

Growth is occurring quickly Wind power has grown 50% each year since 1970 Why? Green-collar jobs Policy

Feed-in tariff policy

SOLAR ENERGY Methods for harnessing solar energy

Passive solar: design of buildings, building materials that absorb sun in the winter and keep interior cool in the summer

Low south facing windows Window overhangs Thermal mass Vegetation

Active solar: devices that focus, move or store solar energy

Flat-plate solar collectors

SOLAR ENERGY

Solar cookers CSP (Concentrated solar power):

curved mirrors focus sun on oil in pipes, this heat oil drives turbines to generate electricity Must be in sunny areas, but has great

potential

PHOTOVOLTAIC CELLS The most direct way to produce

electricity is using PV systems Light causes a plate to release

electrons which are attracted by electrostatic force to opposing plates

Wires connecting plates allows for the flow of a current that can be used as electricity

This is what runs your calculator or watch, as well as homes and buildings

Thin-film solar cells are lightweight and less bulky, they are also cheaper.

Net-Metering versus battery storage

BENEFITS AND DRAWBACKSBenefits Inexhaustible as an energy source Energy hitting the planet is more than enough Clean technologies with no moving parts that last

for 20-30 years Local, decentralized power Reduces deforestation Development of green-collar jobsDrawbacks Location Cost Efficiency

WIND ENERGY Wind turbines turn blades

which rotate a nacelle to convert kinetic energy of wind into electrical energy

Some turbines yaw to respond to wind direction

Growth is fast, doubling every 3 years

Government has had a series of short-term tax credits

Could supply up to 1/5 of our electrical needs by 2030

Offshore sites hold promise Wind is about 20% greater over

water and has less turbulence

BENEFITS AND DRAWBACKS Benefits No emissions (other than manufacturing equipment) EROI of 11:1 Use less water than conventional power plants Can be used on small and large scales Farmers and ranchers can lease their land for development

Drawback Intermittent resource (batteries or hydrogen cells can be

used to store energy for later) Wind varies globally Local residents often oppose wind farms

NIMBY Threat to birds and bats

GEOTHERMAL ENERGY

Energy that arises from beneath the Earth’s surface (caused by pressure and radioactive decay of elements) Remember The Geysers in

California? Can sometimes be

harnessed at the surface from geysers, but more often we have to drill into heated groundwater

GEOTHERMAL ENERGY Reduced emissions but may not be sustainable

Overuse Change in geothermal activity of the planet

EGS (Enhanced Geothermal Systems) may allow geothermal to be used everywhere Engineers pump water into extremely deep wells to create

artificially heated groundwater May cause minor earthquakes

Heat pumps can be used just about anywhere GSHP’s

OCEAN ENERGY SOURCES

Kinetic energy from natural motion of the water can generate electrical energy Tidal Energy

Dams across the outlets of tidal basins Wave and Current Energy

Technology is still being developed

Thermal Energy can be used to heat chemicals that would spin turbines and create energy Ocean Thermal Energy Conversion (OTEC)

HYDROGEN All energy alternatives can be used to

generate electricity, but it is only useful if it can be stored

This is why most car run on gasoline from oil

Fuel cells that consist of hydrogen may be an alternative to this problem

Electricity generated from an alternative source could be used to produce hydrogen

Fuel cells (batteries of hydrogen) could then produce electrical energy for cars, phones, heating, ect.

Hydrogen fuel can be produced from water or other matter

Hydrogen gas doesn’t really exist on Earth Electrolysis of water produces pure

hydrogen without emitting any pollution Environmental impact will depend upon

Source of hydrogen Source of electricity for electrolysis

FUEL CELLS

Isolated hydrogen gas can be used to produce electricity within fuel cells

Basically the opposite of electrolysis

BENEFITS AND DRAWBACKS

Benefits We will never run out Energy efficient Silent and non-polluting

Drawbacks Lack of infrastructure Leakage of hydrogen can deplete

stratospheric ozone

THERE’S NO TOMORROW

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http://www.youtube.com/watch?v=VOMWzjrRiBg17:15-End Challenges