Unit 6

Question 1

Nonrenewable Energy Resource

Answer 1

An energy source with a finite supply (fossil fuels and nuclear fuels)

Question 2

Fossil fuels (and how they form)

Answer 2

A fuel obtained from biological material that became fossilized millions of years ago

(ex: coal, oil, natural gas)
- detritus that is not decomposed gets buried under layers of sediment, subject to heat and pressure– becomes gas

Question 3

EROEI

Answer 3

A way to determine the energy required to produce a fuel:

Energy obtained from the fuel/Energy invested to obtain the fuel

Question 4

Cogeneration

Answer 4

The use of a fuel to generate electricity and produce heat.

-efficient

Question 5

Petroleum

Answer 5

A fossil fuel that is located underground in rocks. It is a liquid mixture of hydrocarbons, water, and sulfur

Question 6

Crude Oil

Answer 6

Liquid petroleum removed from the ground

Question 7

Oil (tar) sands

Answer 7

Slow-flowing, thick/sticky deposits of bitumen, mixed with sand, water, and clay

Question 8

Bitumen

Answer 8

A degraded form of petroleum that forms when petroleum deposit is not capped with nonporous rock. Petroleum migrates to the surface of Earth and is modified by bacteria

Question 9

Fission

Answer 9

A nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into 2+ parts, releasing additional neutrons and energy in the form of heat

Question 10

Fuel Rods

Answer 10

A cylindrical tube that encloses nuclear fuel within a nuclear reactor

Question 11

Control Rods

Answer 11

A cylindrical device inserted between the fuel rods in a nuclear reactor to absorb excess neutrons and slow or stop the fission reaction

Question 12

Fractional Distillation

Answer 12

Separation of a liquid mixture based on boiling point

Question 13

Hydraulic Fracturing

Answer 13

Method of extracting natural gas from shale rock. (use water to break rock)
*lots of freshwater used

Question 14

Natural Gas

Answer 14

Mostly methane, underground, used as fuel, found with petroleum (above oil)

Question 15

Energy Efficiency

Answer 15

using technology that requires less energy to perform the same function

Question 16

Moderator (in a nuclear reactor) **FIX

Answer 16

A substance (water, graphite) that slows down neutrons to continue the fission chain reaction at a constant rate. Important so the reaction does not go too fast and lead to a meltdown.

Question 17

High and low level radioactive waste

Answer 17

High: toxic, nuclear waste
Low: low radioactivity, no significant danger

Question 18

Sub-bituminous

Answer 18

In between lignite and bituminous coal

Question 19

Liquid Petroleum Gas

Answer 19

A group of hydrocarbon gases obtained from crude oil refining

Question 20

Give the formula for calculating EROEI. What type of value is desired when calculating EROEI?

Answer 20

Energy obtained from the fuel/Energy invested to obtain the fuel
better to have a high EROEI because you will obtain a high amount of energy by investing a low amount of energy

Question 21

Explain the process of electricity generation.

Answer 21

Atoms, the tiny building blocks of all things on Earth, are composed of protons, neutrons, and electrons. Electrons, which have a negative charge, are moved between atoms by electrical and magnetic forces. This produces an electric current. Power plants use turbines to rotate magnets inside copper wire. This creates electron movement, which in turn produces electricity.

Question 22

What is cogeneration?

Answer 22

Simultaneous production and use of two different energy forms (from one energy source within the same facility). EFFICIENT
The second energy source, which is produced as a byproduct of the first, is used rather than wasted
Electrical energy production generates a lot of heat– can be used to raise the temp of gas or water which is used to supply large buildings

Question 23

List and describe the five types of coal indicating time to form, water and energy content. Indicate which type of coal is preferred for burning and why

Answer 23

Peat: NOT COAL, precursor to coal 0 years, partially decomposed matter (vegetation in forest dies), lowest heat + carbon content, highest moisture,
Lignite: (brown coal) Millions of years, peat becomes buried deeper, compressed into lignite, low sulfur content, limited supplies in most areas
Subbituminous
Bituminous: (soft coal) hundred of millions of years, lignite layers buried deeper, increased pressure compresses lignite into soft, bituminous coal, extensively used as a fuel because of its high heat content, large supplies, normally has high sulfur content
Anthracite (hard coal) 280-380 million years, deeper burial, years of increased pressure, tectonic activity, and heat. This transforms bituminous coal into anthracite coal. It is highly desirable because of its high heat content and low sulfur content; supplies are limited in most areas. Lowest moisture, highest heat and carbon content

Question 24

What are the advantages and disadvantages of using coal as an energy resource?

Answer 24

Advantages:
coal is energy-dense and plentiful (used to generate electricity, make steel
coal is easy to obtain through surface mining
when coal is extracted from the ground, low cost
it is easy to handle and needs little refining before it is burned
Disadvantages:
negative environmental consequences of tailings from surface mining
when surface coal is used up, subsurface mining becomes necessary. The technological demand price, and negative human health effects increase
Coal releases sulfur into the atmosphere when burned. Trace metals are found in coal (mercury, lead, arsenic). When coal is burned and releases the impurities, increase in sulfur dioxide, increase in air pollutants in atmosphere (ex: particulates)
Lignite and anthracite have low sulfur content. Bituminous coal is higher
Coal companies have attempted to reduce the chemical compounds released in the air by washing their coal in different organic compounds. Some of these compounds can be toxic
Coal burning leaves ash behind. If large accumulation of ash spills, it can destroy houses, requires a lot of $$ to clean up
Air pollution: coal is 60-80% carbon. When burned, converted into CO2. Coal produces more CO2 than oil or natural gas

Question 25

How is oil obtained from the ground? How is petroleum formed? What is petroleum used for?

Answer 25

Petroleum is formed from the remains of ocean-dwelling phytoplankton. Deposits of phytoplankton are found where porous sedimentary rocks (ex: sandstone) are capped by non-porous rocks. Petroleum fills the pore spaces in the rock when it forms. Geologic events related to tectonic cycle may deform the rock layers, creating a dome shape. Petroleum is less dense than the rock, so over time, it migrates upwards towards the highest point in the porous rock, where it is trapped by the nonporous rock. Petroleum producers drill wells into a deposit and extract the petroleum with pumps. After extraction, the petroleum is transported to a petroleum refinery by pipeline (if well is on land) or by supertank (if underwater) Petroleum contains natural gas-extracted and used as fuel Crude oil (liquid petroleum) can be further refined into a variety of compounds: (tar, asphalt, gasoline, diesel, kerosene) They are distinguished by temperature at which they boil (boiling point). Therefore, they can be separated by heating the petroleum. This process takes place at an oil refinery (large factory). The refining process is complex + dangerous + costly. Uses of petroleum: mostly transportation, plastics, lubricants, cleaning solvents

Question 26

Explain the process of fractional distillation in refining crude oil.

Answer 26

Fractional Distillation: Crude oil is heated to vaporize it Heated crude oil is put into a fractionating column As the vapor rises, it cools When is a substance reaches a height where the temperature of the column equals the boiling point of the substance, it will condenser to form a liquid The substance with the lowest boiling point will condense at the highest point in the column Liquids are let out of the column at different heights

Question 27

What are the advantages and disadvantages of petroleum?

Answer 27

Advantages: Liquid- easy to transport and use. More clean-burning (leaves little contamination) than coal. Produces less CO2 than coal Disadvantages: Oil contains sulfur and trace metals (mercury, lead, arsenic) and releases them when burned. Where oil is extracted there is risk of spills and leaks. Oil spills in marine water come from runoff from land, rivers, airplanes, and small boats. Destroys habitats of animals living near oil wells or pipelines. Oil fields near villages- crude oil covers ground-- health effects

Question 28

What type of mining is used to obtain the oil? | What are some environmental effects of mining oil?

Answer 28

Oil sand mining: Mining bitumen is much more energy-intensive than conventional drilling for crude oil (used to obtain Bitumen) Surface mining creates large open pits (open pit mining) Extracting bitumen from other materials contaminates water Oil sands require so much energy before arriving at the refinery, a low efficiency system. Also, more CO2 is released than in conventional oil production

Question 29

What are the advantages and disadvantages of natural gas?

Answer 29

Advantages: natural gas contains fewer impurities than coal and oil, therefore emits almost no sulfur dioxide or particulates during combustion Emits less CO2 than coal Cleanest fossil fuel Disadvantages: Natural gas that leaks after extraction is expected to be a contributor to atmospheric methane (absorbs more infrared than CO2) The process of hydraulic fracturing releases natural gas from host rock. Fracking uses lots of chemicals. Fracking also uses a lot of water, which can become contaminated There can also be groundwater contamination resulting from the drilling of natural gas wells.

Question 30

Photovoltaic Cells

Answer 30

a system of capturing energy from sunlight and converting it directly into electricity

Question 31

Concentrating solar thermal power, disadvantages, how different from thermal power plant

Answer 31

CST systems are a large scale application of solar energy to electricity generations. CST systems use lenses or mirrors and tracking systems to focus the sunlight falling on a large area into a small beam (like magnifying glass). The heat of the concentrated beam is used to evaporate water and produce steam that turns a turbine to generate electricity. They are different from thermal power plants because the energy to produce the steam comes directly from the Sun, rather than from fossil fuels. Disadvantages: - Large amount of land required - Inability to generate electricity at night -Best in direct sunshine

Question 32

Geothermal energy

Answer 32

heat energy that comes from the natural radioactive decay of elements deep within Earth (taking advantage of the fact that convection currents bring hot magma toward the surface of Earth which heat up groundwater) Stored in earth’s mantle, used to heat and cool buildings Large geothermal plants use steam to turn turbines Geothermal Heat Pumps: used for homes and buildings Winter: the water is pumped down into the earth to get heat and distribute to home Summer: heat of the house is pumped down and distributed to earth

Question 33

hydroelectricity

Answer 33

electricity generated by the kinetic energy of moving water. It is the second most commonly used form of renewable energy in the U.S The kinetic energy of moving water is captured by a hydroelectric power plant, where it is used to turn a turbine

Question 34

Wind energy

Answer 34

energy generated from the kinetic energy of moving air. (Wind turns the blades of a wind turbine and the blades transfer energy to the gear box that in turn transfers energy to the generator that generates electricity. Offshore wind turbines are the most desirable, they are also typically installed in rural areas. They must also be close to electrical transmission lines with enough capacity to transport the electricity they generate to users-- grouped together.

Question 35

hydrogen fuel cells

Answer 35

an electrical-chemical device that converts hydrogen into an electrical current. Combines hydrogen and oxygen gas to create electricity and water - 2H2+O2 → energy+2H2O - Current problems: cost, weight of the battery (too heavy will decrease efficiency) - Other issues: obtaining hydrogen without using fossil fuels, distribution network, storage of the fuel in the vehicle, risk of explosion