Chapter 18 Biology

An advantage of subsurface (underground) coal mining is that it: A. employs more people than surface mining techniques and thus creates more jobs. B. is safer for the miners than surface mining techniques. C. is cheaper than surface mining techniques. D. All of these are advantages.

A

Emissions from a coal-fired power plant include all of the following except A. oxygen. B. carbon dioxide. C. mercury. D. arsenic.

A

How long are coal reserves expected to last in West Virginia? A. 50 years B. 100 years C. 500 years D. Forever

A

Environmental Impact Statement

A document that outlines the positive and negative impacts of a proposed federal action (including alternative actions and the option of taking no action); used to help decide whether or not that action will be approved.

Surface mining

A form of mining that involves removing soil and rock that overlays a mineral deposit close to the surface in order to access that deposit.

Energy Return On Energy Investment (EROEI)

A measure of the net energy from an energy source (the energy in the source minus the energy required to get it, process it, ship it, and then use it).

If you lived near an areas where mountaintop removal mining was being done, would you be satisfied with the reclamation process 'and final product? What are the advantages and disadvantages of this type of reclamation?

Answer: Answers will vary regarding satisfaction. Advantages include having flatter land that can be used for other purposes such as industry or recreations (many very mountainous areas have little industry do to the lack of suitable space to build industrial sites.) Disadvantages include the loss of cultural and community ties to the original mountain and stream habitat, loss of tourism, and potential that the area may still be contaminated.

Which of the problems associated with extraction and burning of coal concern you the most: the environmental damage or the social costs? Explain.

Answers will vary. Those concerned with environmental damage may mention things like habitat destruction and its effect on species, the loss of ecosystem services, or the loss of forests leading to fewer recreational opportunities. Those concerned with the social aspects may mention things like the problems or declines in property values or community integrity. Some students may be unwilling to choose one over the other, giving both equal weight.

Which country has the largest coal reserves? A. China B. The United States C. Canada D. Russia

B

Which of the following is an example of reclamation? A. Reworking coal mines to extract more coal B. Replanting the site of mountaintop removal with grass and pine trees C. Returning land to the people who originally owned it D. Filling in a subsurface mine

B

Which of the following is nottrue about coal? A. It produces more air pollution than other fossil fuels. B. It is difficult to ship. C. Extraction is relatively inexpensive. D. The United States has an abundant supply of it.

B

Compare and contrast the two coal mining methods used in Appalachia: mountaintop removal and subsurface mining.

Both methods can be used to access coal in this region but subsurface mining is the older technique and it employs more workers than MTR. Subsurface mining is only useful for thick seams of coal whereas MTR is used when coal is present in many thinner seams. MTR is safer for the worker but not for the surrounding community; it does more damage to the area around the mine and leaves behind a very different ecosystem. Subsurface mining is more dangerous for workers but has less impact on the surrounding community and ecosystem. Both mining methods can lead to the production of acid mine drainage as water washes through mined areas picking up acidic compounds but this is more of a problem with subsurface mines, even mine shafts that are closed or no longer used.

What other methods could be used to spin a turbine and generate electricity?

Burning any fuel to heat the water and produce steam would turn the turbine; other ways to heat the water include nuclear reactions or naturally heated water such as in hot springs or geothermal sources. Physically spinning the turbine can be done with wind, falling water, or the labor of animals (even a person on a bicycle could turn it).

Surface strip mining techniques are used when: A. mines are located close to human settlements. B. coal is located in thin seams in mountainous areas. C. thick coal seams are close to the surface in relatively flat areas. D. it is too dangerous to use explosive charges to access the coal.

C

Mining Hazards

COAL DUST Far more miners die from pneumoconiosis (black lung disease) caused by breathing coal dust than from mining accidents. In 2007, the Centers for Disease Control and Prevention reported 525 coal miner deaths from pneumoconiosis, compared to 18 accidental deaths. FIRE Some underground coal mine fires have been burning for hundreds of years; a fire in an abandoned mine in Centralia, Pennsylvania, burning since 1962, has forced the abandonment of the town. EXPLOSIONS AND MINE COLLAPSE Methane gas fumes and coal dust are the most common causes of mine explosions; 362 miners died in the West Virginia Monongah coal mine explosion in 1907-the worst mining accident in U.S. history; 29 died after an explosion in the Upper Big Branch mine in 2010. TOXIC FUMES A vigil being held for 12 miners who died from carbon monoxide poisoning after an explosion trapped them in the Sago Mine in West Virginia in 2006.

Define and describe the process of carbon capture and sequestration. Why is this process necessary? What are the costs and benefits of the process?

Carbon capture and sequestration is a process whereby industrial facilities that normally release CO2 into the atmosphere prevent its release and instead capture and store it. In one model, as the waste gas is expelled it travels through a solvent that binds to CO2. The solvent and CO2 are separated and some of the CO2 can be used by industry to carbonate beverages, etc. The remaining CO2 is piped deep underground into old oil wells, unmineable coal seams, or deep salt formations. The process is necessary because CO2 is a primary greenhouse gas. The increased use of coal and other fossil fuels by humans has resulted in too much CO2 in the atmosphere, leading to increases in planetary temperatures. Therefore, we are trying to limit our impact by reducing the amount of CO2 we contribute to the atmosphere. The benefit is that less CO2 is added to the atmosphere. The cost is in the extra energy required for the process—estimates range from 25-40% more energy (and thus more coal) to power the process.

Coal is the main fossil fuel used to produce electricity in the United States, though its use decreased 6% between 2010 and 2013 due mainly to an increase in nuclear power. Increasing the use of renewable fuels and taking steps to improve energy efficiency and conservation could decrease the role coal plays in energy production.

Coal 2 Infographic

Coal is formed over long periods of time as plant matter is buried in an oxygen-poor environment and subjected to high heat and pressure. Places with substantial coal deposits that are retrievable with current technology are called coal reserves.

Coal 3 infographic

Coal reserves are not evenly distributed around the world. The United States has 28% of the world's coal reserves, with much of its best, low-sulfur bituminous, coal found in Appalachia.

Coal 4 infographic

Surface mining techniques are used when coal seams are close to the surface, or in the case of Appalachia, when the coal seams are thin and can't be efficiently accessed via subsurface mining. In Appalachia, the forests are first clear-cut and then explosives are used to blast away part of the mountain. Heavy equipment then digs through debris, dumping the overburden (soil and rock) into the nearby valley, burying streams as the valley is filled in. The exposed coal is dug out and some processing is done on site. Coal sludge left over from processing is stored in ponds on the mining site.

Coal 5 infographic

Subsurface mines are used to access large deposits or thick seams of many minerals and ores, including coal. Modern mining depends on powerful machinery to drill out tunnels and remove and transport the materials.

Coal 6 infographic

The use of coal contributes to environmental and health problems when it is mined or burned. Surface mining, especially mountaintop removal, produces the most environmental damage. Miners and people living in coal mining communities are most at risk for health problems, but air pollution from burning coal affects individuals and ecosystems far removed from the actual power plant.

Coal 7 infographic

The capture of CO2 and subsequent storage that prevents it from reentering the atmosphere will greatly decrease coal's contribution to global climate change. A variety of CCS methods are currently in research and development or are being tested as pilot programs.

Coal 8 Infographic

U.S. federal law requires that after a surface coal mine ceases operations, the land must be restored to close to its original state. However, mining sites never truly or fully recover. After the coal is removed, the area is recontoured to produce a slope, and grasses are planted. To replace the mountain streams that were buried by the mining removal process, new channels are constructed to accommodate water flow— but these channels do not support the diverse biological communities that once existed. No matter how much care goes into reclamation, the area will not support a mountain forest community like it once did. However, if done well, a new ecological community may develop.

Coal 9 Infographic

The most common way to generate electricity is to heat water to produce steam; the flow of steam turns a turbine inside a generator to produce electricity. This schematic shows TVA's coal-fired Kingston plant in Tennessee, which generates 10 billion kilowatt-hours a year by burning 13,000 metric tons of coal a day, supplying electricity to almost 700,000 homes.

Coal Infographic

Key Concept

Coal deposits are located throughout the world, though some areas have a larger supply than others.

Key Concept

Coal is a fossil fuel, formed over long periods of time when dead plant material was buried and subjected to high heat and pressure.

Key Concept

Coal is a valuable fuel, but coal mining creates significant environmental and health problems for workers, community members, and the local ecosystem.

In your own words, describe the process of coal formation. Why is coal a finite resource?

Coal is formed when areas of plant material are buried and there is little oxygen for decomposition. Decomposition of the plant material proceeds slowly (on a geologic time scale), ultimately forming peat. That peat is subjected to geologic processes of pressure and high heat, forming coal. Initially, soft coal (lignite) is formed. If heat and pressure continue for thousands of years longer, harder types of coal (bituminous and anthracite) form. This process occurs on a geologic time scale—millions of years. This means no more coal will be produced on a time scale that is relevant to our use. Therefore, what coal currently exists is all we can depend on, making coal a finite resource.

Key concept

Coal is the leading fuel used for electricity production. It is burned to heat water to produce steam; the steam turns a turbine connected to a generator, producing electricity.

Why aren't coal reserves found everywhere?

Coal reserves are only found in areas where the swampy areas that provided the organic material were located.

Coal can be used to generate electricity by: A. sending a current though the pulverized coal. B. melting the coal and sending its electrons across conductive wires. C. pouring liquefied coal over a turbine, which triggers the release of electrons from copper wire. D. burning the coal to make steam, which turns a generator that makes electricity.

D

True or False: Mine reclamation projects at mountaintop removal sites focus on re-creating the mountain habitat and then reintroducing native plants and animals.

FALSE

True or False: Worldwide and in the United States, coal is used to produce more than half of all electricity.

FALSE

Coal

Fossil fuel formed when plant material is buried in oxygen-poor conditions and subjected to high heat and pressure over a long time.

Peat is found in many areas of the world today, such as the peat forests of Indonesia and the peat bogs of Ireland. Will this peat eventually turn into coal?

Given enough time, if the peat becomes buried under sediments, deep enough to be exposed to high heat and pressure, then it could be converted to coal. But this process takes a long time - both for enough sediments to accumulate to provide the pressure and heat needed, and the time it takes for the chemical conversion to take place once the peat is buried deep enough.

Core Message

Human society runs on energy, and coal continues to be a major reliable energy resource. However, coal mining causes irreversible environmental degradation, and the by-products of mining and burning coal pose significant environmental and health risks. Despite these drawbacks and the availability of renewable, cleaner energy sources, coal's availability and industrial presence keep it a major energy player. Researchers are developing ways to lessen the impact of burning coal, but as long as we continue to use it, much of the impact of mining will remain.

If successful, CCS will reduce coal's contribution to climate change—a significant outcome. What impact would it have on the negative consequences of extracting coal?

It will not reduce the negative effects of extracting coal -- the coal will still be extracted and burned. It may even increase the need to extract even more coal if the energy needed to fuel the CCS process comes from burning even more coal.

Key Concept

Mountaintop removal is a cost-effective surface mining method used to obtain coal, but it creates tremendous environmental damage and employs fewer miners than other methods.

Fossil Fuels

Nonrenewable resources like coal, oil, and natural gas that were formed over millions of years from the remains of dead organisms.

Carbon Capture and sequestration

Removing carbon from fuel combustion emissions or other sources and storing it to prevent its release into the atmosphere.

Reclamation

Restoring a damaged natural area to a less damaged state.

Subsurface mining

Sites where tunnels are dug underground to access mineral resources.

Key Concept

Subsurface mining is used to access deep, thick coal seams. It is less environmentally damaging and employs more workers than surface mining but is a hazardous job.

Key Concept

Surface coal mines must undergo reclamation once they are closed; this reduces the environmental damage of mining but does not eliminate it.

Mountaintop Removal

Surface mining technique that uses explosives to blast away the top of a mountain to expose the coal seam underneath; the waste rock and rubble is deposited in a nearby valley.

True or False: If we paid the true costs of using fossil fuels like coal, the price of our electricity would likely go up.

TRUE

Energy

The capacity to do work.

Why isn't the coal found in the regions where mountaintop removal is used removed with subsurface mining instead?

The coal in these areas occurs in thinner seams that makes it inefficient and unreasonable to try and remove it with traditional subsurface mining techniques.

Electricity

The flow of electrons (negatively charged subatomic particles) through a conductive material (such as wire).

Key Concept

The negative impact of burning coal can be addressed by capturing pollutants before they are released or converting coal to a liquid or gaseous fuel that burns cleaner.

overburden

The rock and soil removed to uncover a mineral deposit during surface mining.

Acid mine drainage

Water flowing past exposed rock in mines, leaching out sulfates. These sulfates react with the water and oxygen to form acids (low-pH solutions).

Why is the overburden dumped into the valley below when it is known that it damages streams and valley habitat?

Where else would it go? It is expensive to haul the overburden to another distant site so the mining operation chooses to dump it over the edge of the work area, into the valley below.