Chapter 19 Coal
energy return on energy investment (EROEI)
(net energy) a metric that allows us to compare the amount of energy we get from any individual source to the amount we must expend to obtain, process, and ship it
How much coal does the US use in a year
1 billion tons
How much coal does is take to generate 1 kilowatt hour of electricity
1 pound
The US has __ times more coal than oil and natural gas combined
10
Subsurface mines also account for ___ of all methane release in the United States
10%
At current rates of usage, proven coal reserves should last about
120 years but longer if deeper reserves can be accessed
The United States has __ of the world's coal reserves, with much of its best, low-sulfur bituminous coal found in Appalachia.
28%
Environmental impact statement
A document outlining the positive and negative impacts of any proposed environmental action (including alternative actions or taking no action); used to help decide whether or notthat action will be approved.
What was majority of the coal used for
American households and businesses
Health impacts of coal
Birth defects Black lung disease
What causes more deaths than mining accidents amoungst miners
Black lung disease(breathing coal dust)
Which fossil fuel produces the most air pollution?
Coal
Fossil fuels include
Coal, petroleum and natural gas
Alterations of nutrient cycle due to coal minging
Extra sulfates, released from blasted rock, have increased nitrogen and phosphorus availability, and in so doing have led to eutrophication microbes transform sulfate into hydrogen sulfide, which is toxic to many aquatic plant species.
Where does most of our energy come from
Fossil Fuels
Coal
Fossil fuel formed when plant material is buried in oxygen-poor conditions and subjected to high heat and pressure over a long period of time
2 most common causes of mine explosions
Methanegas fumes and coal dust
Fossilfuel
Non renewable carbon based resources that were formed over millions of years ago
carbon capture and sequestration
Removing carbon from fuel combustion emissions or other sources and preventing its release into the atmosphere.
Surface mining
Removing dirt and rock that overlays a mineral deposit close to the surface in order to access that deposit.
Advantages for using coal
Safer to ship, cheaper to extract, and the US is more abundant of it
Dangerous toxin found in streams downhill from mining operations
Selenium
Subsurface mines
Sites where tunnels are dug underground to access mineral resources.
______ are among the most controversial features of the landscape created by mountaintop removal
Slurry impoundments—reservoirs of thick black sludge that accompany each mining operation
Mountain top 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
Energy
The capacity to do work
Overburden
The rock and dirt removed to uncover a mineral deposit during surface mining.
Acid mine draining
Water flowing past exposed rock in mines that leaches out sulfates. These sulfates react with the water and oxygen to form acids (low-pH solutions).
Challenges to subsurface mining
Water seeps easily into tunnels, and as it does, toxins leech from the surrounding rocks into the gathering pools,
Strip mining
Workers use heavy equipment to remove and set aside overburden so that they can harvest the coal beneath. When they finish mining one strip of land, they return the overburden to the open pit and move on to a new strip.
The US's leading coal producer in 2010
Wyoming, then Appalachia
Strip mines are used in areas like
Wyoming, where the coal is close to the surface and the ground above is fairly level.
What is peat
a soft mash of partially decayed vegetation
Coal has a EROEI of
about 8:1 (8 units of energy produced for every 1 unit consumed for a net production of 7),
More than 40% of electricity generation worldwide, and 45% in the United States, comes from
burning coal
How do co fired power plants work
by feeding pulverized coal into a furnace to generate heat, which then powers a system that produces electricity.
The next big challenge is
carbon capture and sequestration
Another emerging clean coal technology involves
chemically removing some of coal's contaminants before burning it
Potential solution for coal mining
clean coal technology—technology that minimizes the amount of pollution produced by coal
Surface mining techinques are used when
coal seams are close to the surface
Ways to us less coal
design and use more energy-efficient appliances reduce our coal consumption through simple conservation efforts like turning off lights and electronics when we're not using them
Coal-fired power plants also generate tons of
fine ashen particles made up mostly of silica
Toxins released from coal that threaten human health
gases (sulfur dioxide, carbon monoxide, nitrogen oxide, and planet-warming carbon dioxide), radioactive material (uranium and thorium), and particulate matter (soot)
Disadvantages to this process is
it requires energy (thus lowering coal's EROEI) and generates hazardous waste (from the toxins found in the coal)
the U.S. Surface Mining Control and Reclamation Act,
mandated that areas that have been surface mined for coal be "reclaimed" once the mine closes
To get coal beneath peaks
miners began by clear-cutting the forest then drilled holes deep into the side of the mountain set dynamite in those holes, and blasted as much as 1,000 feet of mountain into a mass of rubble known as overburden
Electricity
natural form of energy (lightning and nerve impulses are electrical) that we have learned to create on demand, producing it in a central location and sending it out via transmission lines to where we want it to go.
Effect of this process
obliterated the forest habitat, buried countless streams, and permanently reordered the land's natural contours.
How 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
Methane
potent greengas
The EPA's new Mercury and Air Toxic standards will
regulate a limit to how much these toxic air emissions power plants could release
Reclamation
requires that the area be returned to a state close to its pre-mining condition
As the layers of minable coal have grown thinner and harder to reach
the coal industry has become both more sophisticated and more destructive in its approach to extracting the coal.
Environmental costs of coal
the destruction of Appalachia, the pollution of Earth's atmosphere with CO2 and other greenhouse gases.
How were Appalachian coal beds established
the gradual accretion of decomposing swamp vegetation compressed and baked by heat and time they were buried under a mud so thick it kept oxygen out Instead of being fully decomposed by bacteria, their remains produced peat more and more layers of sediment were laid down over the peat, pressure and heat compressed it into the denser rocklike material that we know as coal
Federal law requires that after ceasing operations
the land used for surface coal mines must be restored to close to its original state
Advantage to subsurface mining
they don't disrupt or permanently alter large surface areas Employ more people
What is the vast majority of coal used for
to generate energy
The EPA would register ____as one of the worst environmental disasters in the eastern United States' history
toxic sludge into the Big Sandy River of Martin County, Kentucky
closed mines
where all the coal has been harvested
