Fossil Fuels

Net energy expresses the difference between energy returned and energy invested.

Net energy = Energy returned - energy invested

Carbon capture and storage remains too unproven to be a viable strategy.

There is no way of knowing if stored carbon will remain underground indefinitely. Injection could contaminate groundwater supplies or trigger earthquakes. The process is very energy-intensive and decreases the EROI of coal.

Natural gas

is a gas consisting primarily of methane (CH4) and other volatile hydrocarbons.

Crude oil

is unrefined oil extracted from the ground.

The world is going to reach peak oil at some point in the near future, raising questions about what other fuels or technologies will replace it. Which fossil fuel was formed from dense, woody material, and has the greatest reserves-to-production (R/P) estimate?

Coal

Clean coal technologies aim to reduce air pollution from coal

Coal can also be dried or converted to a cleaner synthesis gas (called syngas) to make it cleaner-burning.

Coal is a hard blackish substance formed from woody organic matter compressed into a dense, solid, carbon structures. The more coal is compressed, the denser its carbon content, and the greater its energy content per unit volume.

Coal is extracted primarily through strip mining, subsurface mining, and mountaintop removal.

It takes energy to make energy

Harvesting energy requires the use of heavy machinery, construction of roads, pipeline, waste ponds, storage tanks, and more — all requiring investments of energy.

A combination of energy efficiency and conservation efforts is essential to creating a sustainable future.

Some estimates hold that the U.S. could save 6 million barrels of oil a day, more than could be gained from Canada's oil sands.

Directional drilling technology allows drillers to bore down vertically and then curve to drill horizontally.

This allows drillers to reach a large radius around each drill pad without constructing additional drill pads.

Methane hydrate

is a solid consisting of molecules of methane embedded in a crystal lattice of water molecules. Found in sediments in the Arctic and ocean floor.

Oil shale

is sedimentary rock filled with organic matter that can be processed into shale oil. Occurs in areas where deposits were not buried deeply enough to be subjected to enough heat and pressure to form oil

To extract oil from oil sands, companies must:

Clear the forest and strip-mine the land. Mix the deposits with hot water and chemicals to separate the bitumen from sand. Store wastewater in toxic tailings lakes.

Hydraulic fracturing, also called fracking, pumps chemically treated water under high pressure into layers of rock to crack them.

Fracking has become a major debate in states above the Marcellus Shale deposit, as it creates many jobs but drew down water resources and, in some cases, polluted water.

What extraction technology pumps chemically treated water under high pressure into layers of rock to crack them, releasing methane?

Hydraulic fracturing

In secondary extraction, solvents, water, or steam is injected into the well to force the remaining oil or gas out by pressure.

This is a much more expensive process than primary extraction.

Clean coal technologies refer to an array of techniques, equipment, and approaches that aim to remove chemical contaminants during the generation of electricity from coal.

This may involve using minerals (calcium, magnesium) that absorb sulfur dioxide or chemical reactions that remove nitrogen oxides.

In 2015, President Obama decided against

approving the pipeline.

Pipelines are subject to corrosion, vandalism, and equipment malfunction.

A wide variety of impacts occurred due to the Deepwater Horizon spill, ranging from birds becoming coated with oil to beach and ocean floor contamination.

Fossil Fuels: Their Formation, Extraction, and Use Fossil fuels were formed hundreds of millions of years ago, from organisms performing photosynthesis.

After death, these organisms ended up in an anaerobic environment, where their organic matter was converted by heat and pressure into a fossil fuel.

To facilitate the transport of tar sands oil to the U.S., TransCanada constructed a large pipeline called the Keystone XL pipeline.

An extension of this pipeline has been proposed to be built through the Dakotas to shorten the distance, increase capacity, and reach productive oil fields in North Dakota and Montana.

Following the OPEC embargo of 1970, the U.S. increased its corporate average fuel efficiency (CAFE) standards.

As fuel prices fell over the next few decades, these standards were not increased further until 2007.

Secondary extraction yields additional fuel

At a typical oil or gas well, as much as two-thirds of a deposit may remain in the ground after primary extraction.

Can we capture and store carbon?

Carbon capture and storage (CCS) involves capturing carbon dioxide emissions, converting the gas to a liquid form, and then sequestering (storing) it in the ocean or underground in a geologically stable rock formation.

Carbon emissions drive climate change Burning fossil fuels alters the carbon cycle, as long-term reservoirs of carbon are liberated and converted to carbon dioxide.

Carbon dioxide is a greenhouse gas, and its emission is recognized as the biggest consequence of fossil fuel use.

Each fossil fuel has its own mix of uses.

Coal, for example, is primarily used for electricity generation.

Energy sources like sunlight, geothermal energy, and tidal energy are perpetually renewable.

Coal, oil, and natural gas are considered nonrenewable because it takes thousands of years for the biosphere to generate the organic matter consumed by our society in a single day of fossil fuel combustion.

Fossil fuel emissions also pose health risks Fossil fuel emissions can affect human health in many ways:

Combusting coal emits mercury, which biomagnifies in food chains. Cancer-causing hydrocarbons such as benzene and toluene are released from burning gasoline. Poisonous hydrogen sulfide evaporates from crude oil. Vehicles and power plants release sulfur dioxide and nitrogen oxides, which cause acid precipitation.

Refining results in a diversity of fuels

Crude oil is a mixture of hundreds of hydrocarbons and must undergo refining, a process that separates the molecules by size.

In general, developed countries consume more fossil fuel than developing countries.

Developing countries tend to use energy for subsistence activities, while developed countries use it for transportation, industry, and other uses. In the United States, coal, oil, and natural gas supply 82% of the total energy demand.

Energy sources are assessed using EROI (energy returned on investment), which is calculated by:

EROI = Energy returned / Energy invested

Ratios rise when extraction becomes easier or more efficient, and lower when resources become depleted and harder to extract.

EROI ratios for conventionaloil and natural gas in the U.S. declined from 24:1 inthe 1950s to 11:1 in recentyears.

The Keystone XL pipeline was estimated to provide thousands of jobs, but many landowners declined TransCanada's offers to buy their land.

Eminent domain, a policy where courts can set aside private property rights, has been used in some cases to take the land anyways.

Where will we turn for energy?

Enormous amounts of energy, money, and technology are now being used to extend our reach for fossil fuels.

The actual amount of years we have left could change if our demand, production, or known reserve levels change.

For example, hydraulic fracturing is allowing us to access tight oil confined in or near shale, increasing reserve levels.

Addressing Impacts of Fossil Fuel Use

Fossil fuel extraction, as shown in Alberta, has direct impacts on landscapes and natural habitats.

We pay all external costs

Fossil fuels have been kept artificially inexpensive due to government subsidies and tax breaks for extraction companies.

Melting ice is opening the Arctic

Global climate change has opened many areas of the Arctic to offshore drilling.

Impacts of oil drilling are primarily due to the infrastructure needed to support it, including access roads, pipelines, housing for workers, excavated soil piles, and sludge storage ponds. Impacts of coal include:

Health risks to subsurface miners due to mine collapse or the inhalation of coal dust. Extensive soil erosion. Acid mine drainage, where sulfide minerals in exposed rock react with oxygen and rainwater to produce sulfuric acid. Habitat loss, especially in areas where mountaintop removal is being conducted.

Sources of Energy

Humanity has devised many ways to harness the renewable and nonrenewable forms of energy available on our planet.

Lecture objectives

Identify the energy sources that we use. Discuss the value of the EROI concept. Describe the formation and extraction of major types of fossil fuels. Assess concerns over the future decline of conventional oil supplies.

Eventually, extraction of any nonrenewable resource will reach a peak, then decline.

If demand holds steady or increases when this happens, shortages are likely. This scenario is called peak oil with petroleum, because it is likely to occur in the near future.

Cogeneration is a process in which excess heat produced during the generation of electricity is captured and used to heat nearby workplaces and homes, and to produce other kinds of power.

Improved design and insulation can also help to reduce heat loss from buildings.

Dependence on foreign energy affects economic security

In 1973, the Organization of Petroleum Exporting Countries (OPEC) resolved to stop selling oil to the United States, creating an energy crisis.

Oil sands are the most ecologically damaging, due to the vast amount of deforestation, water usage, and toxic wastewater release. The risks of hydraulic fracturing are not fully understood, but potential concerns include:

Leakage of fracking fluids from drilling shafts into nearby aquifers. Movement of methane upward and into aquifers. The production of air pollution due to the release of methane and volatile organic compounds. Contamination of injected water with salts, radioactive elements, and toxic chemicals found in the deep rock. Causing minor earthquakes.

Energy intensity is the energy use per dollar of Gross Domestic Product (GDP).

Lower energy efficiency indicates a greater efficiency in electricity use.

The health and environmental impacts of fossil fuels are external costs that we pay as a society:

Medical expenses. Environmental cleanup. Long-term damage from climate change.

About 2.7% of natural gas piped tohomes and businesses escapes into the air.

Methane also escapes into the air during oil drilling, because pipelines are often not in place to collect it.

We are exploiting new fossil fuel sources

Methane hydrate is also abundant, but so far only Japan has attempted to extract it due to concerns about accidental releases of methane.

Nature offers us a variety of energy sources

Most of the Earth's energy comes from the sun, which drives wind, the water cycle, and photosynthesis.

We are extending our reach for fossil fuels in several ways:

Mountaintop mining for coal. Secondary extraction from existing wells. Hydraulic fracturing for oil and gas. Offshore drilling in deep waters Exploiting new "unconventional" fossil fuel sources

Which fossil fuel can escape during transportation, enter the atmosphere, and directly become a greenhouse gas?

Natural Gas

Coal-fired power plants use coal combustion to convert water to steam, which turns turbines to produce electricity.

Natural gas is used for electricity generation, heat, and cooking. Petroleum is used as fuel for vehicles and petroleum products are found in many household items.

The current estimate of oil reserves is 1.7 trillion barrels and the rate of production is 32 billion per year. 1.7 trillion / 32 billion = 53 years remaining.

Natural gas reserves are estimated to last 54 more years; coal's R/P ratio is about 110 years.

Oil and gas wells are being drilled deeper, and into places that were once unreachable (Arctic sea beds, farther offshore in the ocean, etc).

New resources, such as oil sands, are also being tapped.

Fuels can leak during transport and storage

Oil and coal are both transported by rail, which carries a risk of derailment and explosion.

Oil continued to leak into the Gulf for three months, as BP's engineers tried to find a way to stop the leak.

Oil continued to leak into the Gulf for three months, as BP's engineers tried to find a way to stop the leak.

Oil sands are a mixture of moist sand and clay containing 1-20% bitumen, a thick and heavy form of petroleum.

Oil sands form when crude oil deposits are partially degraded by bacteria.

Alberta's Oil Sands and the Keystone XL Pipeline

Oil sands, also called tar sands, are layers of sand or clay saturated with a viscous, tarry type of petroleum called bitumen. Huge areas of tar sands are available around Alberta, Canada, and the impacts of extracting and processing the oil are huge.

Protests quickly began when this extension was proposed, with objections including:

Oil use should be reduced, and we should be transitioning to renewable energy instead. Oil spills could contaminate the Sandhills area of Nebraska and the Ogallala Aquifer

Until oil prices began rising in 2003, extracting and processing oil from these deposits was not profitable.

One of the biggest buyers of tar sands oil is the United States.

Frigid temperatures, ice floes, winds, waves, and brutal storms make conditions challenging and accidents likely.

Only Royal Dutch Shell has attempted to drill in the Arctic, but a series of accidents and protests led them to withdraw from drilling as of 2015.

When plants and other organisms die and are buried in sediments under particular conditions, their stored chemical energy may eventually be incorporated into fossil fuels, such as oil, coal, and natural gas.

Other forms of energy in the earth include geothermal energy from the core and from the bonds between protons and neutrons in atoms.

Lecture objectives 2

Outline ways in which we are extending our reach for fossil fuels. Examine environmental impacts of fossil fuel use, and explore ways to minimize these impacts. Assess political, social, and economic aspects of fossil fuel use. Discuss strategies for conserving energy and enhancing efficiency.

Fossil fuel extraction often leads to a flush of high-paying jobs and economic activity that seems to outweigh any potential environmental costs.

Over time, these booms go bust, and the legacy of pollution may remain for generations.

Which of these does not accurately describe changes in U.S. energy use since 1970?

Per capita energy use has decreased. Energy intensity has decreased. Energy efficiency has decreased.

The economically recoverable portion of the fuel depends on costs of extraction and market prices.

Proven recoverable reserves are both technologically and economically recoverable.

We are drilling farther offshore

Roughly 35% of the oil and 10% of the natural gas extracted in the United States today come from offshore sites, such as the Gulf of Mexico and coastal California.

We are depleting fossil fuel reserves

Since fossil fuels are nonrenewable, the total amount available on Earth declines as we use them.

We rely mostly on fossil fuels

Since the industrial revolution, fossil fuels have replaced biomass as our dominant source of energy.

There is an estimated 3 trillion barrels of oil shale to be extracted, much of it in the United States.

The EROI for this oil is low, ranging from 4:1 to 1.1:1.

Recent regulations have restricted how much power devices can use while in standby, sometimes called "vampire" power loss.

The U.S. EPA's Energy Star program labels refrigerators, dishwashers, and other appliances for their efficiency.

Fossil fuels have many uses

The amount of a fossil fuel that a nation extracts and consumes depends on its size and level of industrialization.

Energy is unevenly distributed

The distribution of fossil fuel reserves varies from region to region.

Economics determines how much will be extracted

The proportions of fuels that are physically accessible to us are called technologically recoverable portions.

Reaching Further for Fossil Fuels

These all increase fuel production, but reduce the EROI ratios of our fuels, intensify pollution, and worsen climate change.

Oil and natural gas are derived from marine plankton that died, sank to the sea bottom, became buried, and transformed by time, heat, and pressure.

These eventually settle under impermeable rock formations, which must be drilled through before the oil and gas can be accessed.

Peak oil will pose challenges: In 1956, Shell Oil geologist M. King Hubbard predicted that the U.S. would hit peak oil in 1970.

This came true, although unconventional sources have increased production back toward those levels.

Deep water drilling technology has outpaced our ability to deal with accidents, as shown by the Deepwater Horizon oil spill in 2010.

This forced a temporary hold on new drilling in 2011, until new rules and regulations could be designed.

Many nations lack adequate fossil fuel reserves to supply their own energy needs and rely on imports.

This gives seller nations more control over energy prices, especially as supplies dwindle.

To reduce its risk, the United States has supported oil sands extraction in Canada, the construction of oil pipelines, and diversified its sources of imported petroleum.

This has also led to repeated attempts to open up oil drilling in the Arctic National Wildlife Refuge (ANWR).

Americans use far more energy per person than people in most other nations.

This indicates that Americans could reduce their energy consumption without significantly impacting their quality of life.

Gains in efficiency may be offset if people engage in more energy-consuming behavior as a result.

This phenomenon is called the rebound effect, and in some cases may completely erase efficiency gains.

Mountaintop mining extends our reach for coal Mountaintop removal mining removes entire mountaintops to access the coal seams running through them.

This produces huge amounts of rock and soil erosion.

Energy conservation describes the practice of reducing wasteful or unnecessary energy use.

This results from behavioral choices.

Energy efficiency describes the ability to obtain a given amount of output while using less energy input.

This results from improved technology.

Overall, pollution from large spills has declined in recent decades, largely due to regulations that emerged as a result of the Exxon Valdez oil spill in 1989.

Today, most oil pollution entering the ocean comes from countless nonpoint sources, such as homes, gas stations, businesses, and cars that leak oil into roadways.

The high energy content makes these more efficient to burn, ship, and store.

We use fossil fuels for transportation, manufacturing, heating, cooking, and to generate electricity.

As a result of the 1970s energy crisis, where does the United States now import most of its oil from?

canada

Which fossil fuel is a mixture of hydrocarbons that must be separated before they can be individually used as different fuels?

oil

What "unconventional" fossil fuel is being extracted in Alberta, Canada, and shipped into the United States through the Keystone pipeline?

oil sands

The separated products of refining are specialized fuels for heating, cooking, transportation, and are also used to make lubricating oils, asphalts, and other petrochemical products.

typical output of refined oil: gas 49.2% Diesel fuel and heating oil 25% jet duel 8.0% liquefied petrolium gases 3.1% heavy fuel oil 2.1% other 12.7%

Petroleum

usually refers to oil, but may also refer to oil and natural gas collectively.