ch.19-21 Flashcards

Question

Natural gas

Answer 1

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.

Answer 2

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.

Answer 3

Sum of the protons and neutrons in an atom

Answer 4

Number of protons per atom. Each element has its own atomic number

Answer 5

Atom where the number of neutrons is greater than the number of protons

Answer 6

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%

Answer 7

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)

Answer 8

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

Answer 9

energy in the form of electromagnetic waves associated with fission and fusion (death and cancer)

Answer 10

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

Answer 11

Nuclear Waste Policy Act (1982) – government to ‘own’ nuclear waste by 1998 Store waste from weapons, but not civilian waste

Answer 12

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

Answer 13

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%

Answer 14

When energy is converted from one form to another, some fraction becomes less useful (heat low-value energy)

Answer 15

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

Answer 16

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

Answer 17

average amount of solar energy 1,330 watts per square meter, 10,000 times more than all commercial energy used annually

Answer 18

using absorptive structures with no moving parts to gather and hold heat ex: greenhouse

Answer 19

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

Answer 20

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

Answer 21

how much of the energy input is converted to useful work ex: A wind turbine converts 60% PV cells: 15 to 20%

Answer 22

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)

Answer 23

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

Answer 24

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,

Answer 25

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

Answer 26

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

Answer 27

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)

Answer 28

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).

Answer 29

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

Answer 30

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.

Answer 31

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.

Answer 32

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

Answer 33

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

Answer 34

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

Answer 35

portion of waste stream which we are most responsible for

Answer 36

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%

Answer 37

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

Answer 38

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)

Answer 39

use to be inexpensive and convenient, rising rent, there is not as much usable land

Answer 40

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.

Answer 41

refuse is sorted to remove recyclable and unburnable materials Higher energy content than raw trash

Answer 42

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.

Answer 43

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

Answer 44

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.

Answer 45

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.

Answer 46

1. Reduce the amount of waste (less packaging) 2. Reuse products 3. Recycle materials

Answer 47

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

Answer 48

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

Answer 49

(1976) Comprehensive program requiring rigorous testing and management of toxic and hazardous substances. * “Cradle (point of generation) to grave (ultimate disposal)” accounting.

Answer 50

chemical and petroleum industries 71%, metal processing and mining 22%, other 7%

Answer 51

(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

Answer 52

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. 40

Answer 53

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.

ch.19-21 Flashcards

(81 cards)