ch.19-21 Flashcards
work
application of force over distance, measured in joules (W=F s)
energy
the capacity to do work
power
the rate at which work is done, measured in watts (P=W/time
newton
force that is needed to accelerate 1 kg 1 meter per second ^ 2. F= m a
Joule
amount of work done when the force of 1 newton is exerted over 1 meter
watt
one joule per second
Global commercial energy production
fossil fuels- 80%. oil- 30%, natural gas- 25%, coal- 20%, renewable sources- 10%, Nuclear- 8%
US energy consumption by sector
Transportation- 45%, Industrial- 19%, Commercial- 18%, Residential- 19%
US energy consumption info
3/4 transprotation used by moter vehechlies mostly petrolium
residential and commercial used mostly for heating, cooling, water heating, lighting,
industrial 1/4 used for mining, milling, and processing of minerals
half of energy in fuels lost during conversion, shipping, and use, much pollution released.
per capita consumption
rich countries use 80% commercial energy, have only 20% of pop.
2035 emerging counties (Chona, India) will consume 60%
China doubled energy consumption over last decade, India twice as much since 2004
US, Germany, Japan same amount
fossil fuels
combustible deposits of earth’s crust, composed of fossils (coal, oil/ petroleum, natural gas)
non-renewable resource, demand will peak b4 end of this decade, share of world energy supply will drop to 73% by 2030
oil (how it’s formed)
oil- Microscopic plants buried under sediment, Heat, pressure, and time turned them into hydrocarbons
how carbon is released into the atmosphere
we have been burning too much C releasing as CO2
CO2 present in the atmosphere, dissolved in the ocean,
in plants (cycles change slowly)
Deepwater horizon
April 22, 2010, drilling platform in
the Gulf of Mexico exploded, 5 million barrels spilled, finally stopped in mid-July 2010
coal
formed- Heat, pressure, and time turned the nondecomposed plant
material into carbon-rich rock
Most laid down during Carboniferous period (286
million to 360 million years ago)
nonrenewable
natural gas (how it’s formed)
natural gas- same way as oil, but at temperatures higher than 100 degrees Celsius
coal resources
coal deposits are ten times greater than conventional oil and gas resources combined
“Proven reserves” - have been mapped, measured, and shown to be economically recoverable. That could increase to thousands of years if estimates of unknown reserves are included.
Oil can last up to 50 years, natural gas up to 53 years, and coal up to 114 years 16
Coal mining
1870 and 1950, more than 30,000 American coal miners died in Pennsylvania Black Lung Disease
Strip mining is cheaper and safer than underground mining. makes
land unfit for other use, Acid drainage damages streams,
Mountaintop removal, practiced in Appalachia, causes streams, farms, and towns to be buried under hundreds of meters of toxic rubble.
Burning coal
burning plants emit radioactivity from uranium and thorium. and releases sulfur and nitrogen oxides,
particulates, and carbon dioxide which contribute to acid rain, air pollution, and global warming.
Coal combustion is responsible for 25% of all atmospheric mercury pollution in the U.S
Ash from coal combustion is stored in open storage ponds, at risk of catastrophic failures causing millions of dollars in damages and polluting local water supplies
oil production
peaked in the production of oil in 1970s
new developed techniques for obtaining oil from ever more remote and extreme places
Canada’s Athabascan tar sands, Brazil’s Santos Basin, Venezuela’s Orinoco Belt, Angola’s Kwanza Basin, the United States’ Bakken formation, and the Arctic sea bed
oil impacts
Disrupts wildlife and plants
Burning oil produces carbon dioxide and nitrogen oxides.
Every year 1.5 billion tons of oil are shipped in ocean tankers or through pipelines. Pipelines carrying tar sands oil have a much higher rupture rate than those for conventional oil.
Hydraulic fracturing
Extraction of natural gas that is tightly bound in shale deposits by applying chemicals and water under high-pressure
Produces large amounts of contaminated wastewater, stored underground, regulations slow
Tar sands
composed of sand and shale particles coated with bitumen, a viscous mixture of long-chain hydrocarbons. They must be mixed
with steam to extract the bitumen, which is then refined. The process creates toxic sludge, releases
greenhouse gases contaminates water, and destroys boreal forest in Canada where most of the
reserves are.
hazardous pollution from refineries
oil- smaller molecules such as propane, butane, or methane, boil off first. Larger molecules, like tar, are left behind
Separated components then provide the material for plastics, lubricating oils, paints, and other chemicals.
Plastic factories are a leading source of air pollution, especially carcinogenic organic compounds.
Natural gas
World’s third largest commercial fuel, 25% of global energy consumption.
Composed primarily of methane (a powerful greenhouse gas).
Produces half as much C O2 as equivalent amount of coal. Most rapidly growing energy source.
Natural gas location
Most reserves in Middle East and Russia.
LNG -Gas is liquefied to ship it over the ocean. A ship explosion would be equivalent to a medium sized atomic bomb.
Methane can be extracted from coal seams.
Atomic Mass
Sum of the protons and neutrons in an atom
Atomic number
Number of protons per atom. Each element has its own atomic number
Isotope
Atom where the number of neutrons is greater than the
number of protons
Nuclear power
Most commonly used fuel is uranium-235: naturally
occurring radioactive isotope of uranium
Occurs naturally at 0.7% of uranium ore, but must be enriched
to 3%
Nuclear fission
Splitting of an atomic nucleus into two smaller fragments,
accompanied by the release of a large amount of energy in the
form of heat (makes nuclear energy)
Nuclear fusion
Joining of two lightweight atomic nuclei into a single, heavier nucleus, accompanied by the release of a large amount of energy
process:
1. Neutron bombardment
2. Nucleus splits into
atomic fragments
3. And free neutrons
4. Free neutrons bombard
U-235 nuclei
5. More free neutrons
released in chain
reaction
Radiation
energy in the form of electromagnetic waves associated
with fission and fusion (death and cancer)
Storing radioactive waste
temporary: nuclear plant facility
(require high security), Underwater storage, Aboveground concrete
and steel casks
no underground storage in US, we lack it
dry casket storage
Storing nuclear waste
Nuclear Waste Policy Act (1982) – government to ‘own’ nuclear waste by 1998
Store waste from weapons, but not civilian waste
Yucca Mountain
identified as permanent storage (19
87). Could store amount produced until 2025. DOE spent billions in feasibility studies. U.S. federal courts demanded site meet EPA safety standard for 1 million years (2004)
Difficulty for science to meet
the year mark Remote possibility of volcanic eruption (1 in 10,000 in next 10,000 years) Site near active fault lines and
water table
Currently not an active storage
site
Energy efficiency
The amount of energy
delivered, The amount of energy supplied
ranges from 0 to 100%
ex: burning natural gas for household cooking
has an efficiency of close to 100%
The second law of thermodynamics
When energy is converted from one form to another, some fraction becomes less useful (heat low-value energy)
how we can be more energy efficient
LED lightbulbs, unplug vampire currents, Green Buildings are those that include extra insulation and coated windows, Install a programmable thermostat, Lower the water temperature setting of water heaters
how transportation can be more energy efficient
Automobiles and light trucks 40%
U.S. oil , ⅕ carbon emissions
Average gas-mileage averages in the United States13.3 mpg in 1973 to 25.9 mpg in 1988
U.S. standards issued in 2012 aimed for 54.5 mpg (23 km/liter) by 2025
Most energy lost in combustion as heat, friction with road, moving weight of car
solar energy
average amount of solar energy 1,330 watts per square meter, 10,000 times more than all commercial energy used annually
Passive Solar Heat
using absorptive structures with no
moving parts to gather and hold heat
ex: greenhouse
Active Solar Heat
pump heat-absorbing medium
through a collector, rather than passively collecting heat in a stationary object
Water heating consumes 15% of the U.S. domestic energy budget, China produces 80% of the solar water heaters
parabolic mirrors
Long curved mirrors focused on a central tube containing a heat-absorbing fluid
Small mirrors arranged in concentric rings around a tall central tower track the sun and focus light on a heat absorber on top of the tower where molten salt is heated to drive a steam-turbine electric generator
Photovoltaic (PV) Solar Cells
Provide 21,000 MW(megawatts) worldwide (0.7% global electricity)
Method of converting sunlight to electricity using layers of materials that either readily give up or absorb
electrons (light excites electrons which are ejected from silicon atoms)
No pollution and minimal
maintenance (15% efficient) Highway signals Entire building
Conversion efficiency
how much of the energy input is converted to useful work
ex: A wind turbine converts 60%
PV cells: 15 to 20%
wind
China is now the world leader in wind power turbine production and the U.S. is second
up to 60 percent efficient, modern windmills typically produce about 35 percent of peak capacity under field conditions
electric prices typically run as low as 3 cents / kWh (cheaper than coal and nuclear)
wind power pros and cons
pros
No fuel costs or emissions Generates income for farmers who rent land for turbines or sell electricity, short planning and construction time
cons
intermittent source, Not enough wind everywhere, Bird mortality (lower than fossil fuel pollution), Power lines needed to transmit the electricity
Hydropower
1925, falling water generated 40% of the world’s electric power
grown 15-fold but fossil fuel use has risen so rapidly that hydroelectric only supplies 20% of electrical generation
Norway uses hydropower for 99% of its electricity
Untapped resources are abundant for hydropower inLatin and Central America, Africa, India, and China
ex:Three Gorges Dam on Yangze River,
dams
Much of hydropower in recent years has been from enormous dams
Human Displacement, Ecosystem Destruction, Wildlife Losses, Large-Scale Flooding due to Dam Failures, Sedimentation, Herbicide Contamination, Evaporative Losses, Nutrient Flow Retardation
Dam Alternatives
Low-Head Hydropower - extract energy from small headwater dams
Run-of-River Flow - submerged directly in stream and usually do not require dam or diversion structure
Tidal and wave energy – When there is a high-tide/low-tide differential, the moving water can spin a turbine to produce electricity
tidal energy
Typical difference between high and low tide is 1-2 ft, Narrow bays may have greater variation, Potential energy difference between low and high tide can be captured with:
o A dam across a bay
o A turbine similar to a wind turbine (hydrokinetic turbines)
biomass
Plants capture about 0.1% of all solar energy thatreaches the earth’s surface.
Organisms use about half of this energy in metabolism, and they store the remaining energy in biomass.
Useful biomass production is estimated at 15 to 20 times the amount currently obtained from all commercial energy sources.
Biomass resources include wood, wood chips, bark,
leaves, starchy roots, and microscopic plant (algae).
biomass pros and cons
Advantages
Reduces dependence on fossil fuels, Often uses waste materials, If trees are planted at same rate biomass is combusted, no net increase in atmospheric CO
Disadvantages
Requires land, water, and fossil fuel energy, Can result in bad air quality
Can lead to:
* Deforestation
* Desertification
* Soil erosion
Burning biomass for energy
As recently as 1850, wood supplied 90% of the fuel used in the United States.
In poor countries, it is still a major source of energy and its use can result in habitat destruction
Even in rich countries wood wood-burning stoves are becoming popular in response to rising oil prices. Some utilities are installing flex-fuel boilers that burn a mixture of coal and biomass.
Methane
Cattle feedlots and chicken farms are a tremendous potential fuel source
Haubenschild dairy farm uses manure from 850 cows,
2001, the farm saved 35 tons of
coal, 1,200 gallons of propane, and made $4,380 selling electricity.
Ethanol & Biofuels Can Enhance Fuel Supplies
Brazil is the world’s leader in alcohol from biomass, mostly sugarcane waste
Currently, half of all corn grown in the U.S. is used for ethanol production.
Crops with high oil content like soybeans, rape, seed, sunflower and palm oil can be used to produce biodiesel fuel
Some countries in Southeast Asia are creating palm oil plantations for biodiesel production, but forests are burned and habitats of endangered animals are destroyed in the. process
Geothermal Energy
tap energy from hot springs,
geyser, Deep wells for community geothermal systems are being developed, Heat from Earth’s crust is never exhausted, Can reduce heating costs by one-half
Geothermal Heat Pumps
Earth is a heat sources in winter and heat sink in summer, Use difference in temperature between surface and subsurface
* Great for heating buildings
* Expensive installation
* High efficiency
municipal solid waste
portion of waste stream which we are most responsible for
US waste percentages
paper 22%, food 22%, yard trimming 13%, plastics 12%, textiles and other 11%, metals 9%, wood 6%, glass 4%
landfill 50%, recycling 23%, incieration 12%, composing 8%, other food managment 6%
Waste disposal methods
Ocean dumping, 8 million tons of plastic debris dumped per year, 1.5 million tons of that washes from
rivers
5.25 trillion pieces of plastic debris in the ocean, 269,000 tons float on the surface, four billion plastic microfibers per square kilometer litter the deep sea
shipping waste to other countries
57.4 Mt (Million Metric Tones) of e-waste globally 2021
waste disposal methods (sanitary landfills
Compacting and burying waste under a shallow layer of soil
Methane gas production by microorganisms
About 600 landfills use methane to produce energy
Contamination of surface water and ground water by leachate (microbe + acids + heavy metals);
US New York’s Fresh Kill landfill (1 million gallons of leachate each day)
few new facilities being opened
Closing a full landfill is very expensive
structure Leachate (microbe + acids + heavy metals); - liquid that seeps through the solid waste and Double liner system (plastic- clay)
waste disposal methods (Landfills)
use to be inexpensive and convenient, rising rent, there is not as much usable land
waste disposal methods (incineration/ energy recovery))
heat derived from incinerated refuse
is a useful resource. Burning garbage is used to create steam used for heating buildings or generating electricity.
Internationally, there are well over 1,000 such waste to energy plants that reduce garbage while generating
needed energy.
Refuse-Derived Fuel
refuse is sorted to remove
recyclable and unburnable materials
Higher energy content than raw trash
mass burn
everything smaller than major furniture and appliances loaded into furnace
Creates air pollution problems.
Reduces disposal volume by 80-90%
Residual ash usually contains toxic material.
problems with incinerations
cost $100- $300 million for a typical municipal facility
high levels of dioxins, furans, lead, and cadmium in ash.
control by removing heavy metals (batteries) and plastics before burning.
Carbon monoxide, particulates, heavy metals
reduced by: Lime Scrubbers (chemical spray neutralizes acidic gases), Electrostatic Precipitators (give “+” charge to “-” particles
Byproduct - Bottom ash (slag) and Fly ash, Must be disposed of in hazardous waste landfills
recycling
half of all aluminum cans are recycled, Old tires are turned into road surfaces, Newspapers become insulation, recycling copper very liquid
Saves money, raw materials, energy, and landfill space
ess pollution and demand for raw resources
Reduces pressure on disposal systems.
5 percent as much energy as
generating new aluminum.
* Japan recycles about half of all wastes.
e-waste
office machines are used 3 to 5 years; most TVs used 5 years; 300 million computers await disposal.
70% of heavy metal contamination comes from e-waste, and batteries make up another 10% to 20%.
In Europe, manufacturers have to track from “cradle to grave” responsibility for their products.
Three Goals of Waste Prevention (3Rs)
- Reduce the amount of
waste (less packaging) - Reuse products
- Recycle materials
hazardous waste
Fatal to humans or laboratory animals in low doses, Ignitable with a flash point less than 60 C, Corrosive, explosive or highly reactive
U.S. industries generate 265 million
metric tons produced yearly, 40 million metric tons released into the
environment
1% of waste stream in U.S
Love Canal
Niagara Falls, NY (Hooker Chem Co)
o 20,000 tons toxic chemical in
canal 900 m long (1942-1953)
o 1978 national emergency
disaster area 700 families
were evacuated
Resource Conservation and Recovery Act
(1976) Comprehensive program requiring rigorous testing and
management of toxic and hazardous substances.
* “Cradle (point of generation) to grave (ultimate disposal)”
accounting.
hazardous waste producers
chemical and petroleum industries 71%, metal processing and mining 22%, other 7%
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
(1980) Modified by Superfund Amendments and Reauthorization Act (S ARA) 1984.
* Aimed at rapid containment, cleanup, or remediation of
abandoned toxic waste sites.
* Establishes a community “right to know.”
* Toxic Release Inventory - Requires 20,000 manufacturing facilities to report annually on releases of more than 300 toxic materials
Superfund Sites
Brownfield Liabilities and
Opportunities
Hazardous Waste Management
Options
Avoid creating waste in the first place, Convert to Less Hazardous
Substances
Secure Landfills.
* Modern, complex landfills with multiple liners and other
impervious layers, covered by a cap. Leachate is
processed and monitoring sees that no toxins escape.
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Phytoremediation
toxic waste storage
Store Permanently
Retrievable Storage - in containers in salt mines or caverns, Can be inspected and periodically retrieved if necessary.
Transportation of hazardous wastes to disposal sites risks accidents
who will bear financial responsibility for abandoned waste sites.
We may need new institutions for perpetual care of toxic wastes and nuclear wastes.
