Chapter 11 Fossil Fuels

Overview of Chapter 11 o Energy Sources and Consumption o How Fossil Fuels are Formed o Coal Coal Reserves and Mining Coal Reserves and Mining Environmental Impacts Environmental Impacts o Oil and Natural Gas Exploration for Reserves of Oil and Natural Gas Exploration for Reserves of Oil and Natural Gas Environmental Impacts Environmental Impacts Arctic National Wildlife Refuge Arctic National Wildlife Refuge o Synfuels o US Energy Strategy

Energy Sources and Consumption o Energy sources used to be local o Now they are worldwide Fossil fuels Fossil fuels Nuclear energy Nuclear energy Electricity Electricity o Energy consumption is different between developing and developed nations 20% of world’s population use 60% of the world’s energy sources 20% of world’s population use 60% of the world’s energy sources

o Per capita energy consumption of selected developed and developing countries

o Energy consumption in the US Industries (production) use the most Industries (production) use the most Heating, cooling, and illuminating building is 1/3 Heating, cooling, and illuminating building is 1/3

Fossil Fuels o Combustible deposits in the Earth’s crust Composed of the remnants (fossils) of prehistoric organisms that existed millions of years ago Composed of the remnants (fossils) of prehistoric organisms that existed millions of years ago Includes coal, oil (petroleum) and natural gas Includes coal, oil (petroleum) and natural gas o Non-renewable resource Fossil fuels are created too slowly to replace the reserves we use Fossil fuels are created too slowly to replace the reserves we use

How Are Fossil Fuels Formed? o 300 million years ago Climate was mild Climate was mild Vast swamps covered much of the land Vast swamps covered much of the land Dead plant material decayed slowly in the swamp environment Dead plant material decayed slowly in the swamp environment

How Are Fossil Fuels Formed o Over time, layers of sediment accumulated over the dead plant material o Coal Heat, pressure and time turned the plant material into carbon-rich rock (coal) Heat, pressure and time turned the plant material into carbon-rich rock (coal) o Oil Sediment deposited over microscopic plants Sediment deposited over microscopic plants Heat pressure and time turned them into hydrocarbons (oil) Heat pressure and time turned them into hydrocarbons (oil) o Natural Gas Formed the same way as oil, but at temperatures higher than 100 °C Formed the same way as oil, but at temperatures higher than 100 °C

Coal o Occurs in different grades Based on variations in heat and pressure during burial Based on variations in heat and pressure during burial o Lignite o Subbitumimous o Bituminous o Anthracite o Most, if not all, coal deposits have been identified Primarily in northern hemisphere Primarily in northern hemisphere

Coal o US has 25% of world’s coal supplies o Known coal deposits could last 200 years At present rate of consumption At present rate of consumption

2 Types of Coal Mining o Surface mining (right) Chosen if coal is within 30m of surface Chosen if coal is within 30m of surface mineral and energy resources are extracted near Earth’s surface by first removing the soil, subsoil, and overlying rock strata mineral and energy resources are extracted near Earth’s surface by first removing the soil, subsoil, and overlying rock strata o Subsurface mining Extraction of mineral and energy resources from deep underground deposits Extraction of mineral and energy resources from deep underground deposits

Environmental Impacts of Mining Coal o Surface Mining Control and Reclamation Act (1977) Requires filling (reclaiming) of surface mines after mining Requires filling (reclaiming) of surface mines after mining Expensive! Expensive! Reduces Acid Mine Drainage Reduces Acid Mine Drainage Requires permits and inspections of active coal mining sights Requires permits and inspections of active coal mining sights Prohibits coal mining in sensitive areas Prohibits coal mining in sensitive areas o Mountaintop Removal Fills valleys and streams with debris Fills valleys and streams with debris

Environmental Impacts of Burning Coal o Releases large quantities of CO 2 into atmosphere Greenhouse gas Greenhouse gas o Releases other pollutants into atmosphere Mercury Mercury Sulfur oxides Sulfur oxides Nitrogen oxides Nitrogen oxides o Can cause acid precipitation

Making Coal Cleaner o Scrubbers o Fluidized Bed Combustion (below)

Oil and Natural Gas o Oil and gas provide 60% of world’s energy They provide 63% of US’s energy They provide 63% of US’s energy

Petroleum Refining o Numerous hydrocarbons present in crude oil (petroleum) are separated Based on boiling point Based on boiling point o Natural gas contains far fewer hydrocarbons than crude oil Methane, ethane, propane and butane Methane, ethane, propane and butane

Oil and Natural Gas Exploration o Oil and natural gas migrate upwards until they hit impermeable rock o Usually located in structural traps

Oil Reserves o Uneven distribution globally o More than half is located in the Middle East

Natural Gas Reserves o Uneven distribution globally o More than half is located in Russia and Iran

How long will Supplies Last? o Difficult to determine and estimates vary o Depends on: How many more deposits will be located How many more deposits will be located What technology might be available extract deeper resources What technology might be available extract deeper resources Changes in global consumption rates Changes in global consumption rates o Experts indicate there may be shortages in 21 st century

Environmental Impacts of Oil and Natural Gas o Combustion Increase carbon dioxide and pollutant emissions Increase carbon dioxide and pollutant emissions Natural gas is far cleaner burning than oil Natural gas is far cleaner burning than oil o Production Disturbance to land and habitat Disturbance to land and habitat o Transport Spills- especially in aquatic systems Spills- especially in aquatic systems Ex: Alaskan Oil Spill (1989) Ex: Alaskan Oil Spill (1989)

1989 Alaskan Oil Spill

o Exxon Valdez hit a reef and spilled 260,000 barrels of crude oil into sound o Largest oil spill in US history o Led to Oil Pollution Act of 1990

Case in Point - Arctic National Wildlife Refuge

Synfuel and Other Fossil Fuel Resources o Synfuel A liquid or gaseous fuel that is synthesized from coal and other naturally occurring sources A liquid or gaseous fuel that is synthesized from coal and other naturally occurring sources Used in place of oil or natural gas Used in place of oil or natural gas o Include: Tar sands Tar sands Oil shales Oil shales Gas hydrates Gas hydrates Liquefied coal Liquefied coal Coal gas (right) Coal gas (right)

US Energy Strategy o Objective 1: Increase Energy Efficiency and Conservation Requires many unpopular decisions Requires many unpopular decisions Examples Examples Decrease speed limit to conserve fuel Decrease speed limit to conserve fuel Eliminate government subsidies Eliminate government subsidies o Objective 2: Secure Future Fossil Fuel Energy Supplies 2 oppositions: environmental and economic 2 oppositions: environmental and economic

US Energy Strategy o Objective 3: Develop Alternative Energy Sources Who should pay for this? Gas taxes? Who should pay for this? Gas taxes? o Objective 4: Meet the First Three Objectives Without Further Damage to the Environment

National Energy Policy (2005)