Flashcards in Chapter 15: energy Deck (38)
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1
What is the mackenzie valley gas project?
a proposal to develop three major gas fields in the mackenzie delta, NWT.
2
examples of fossil fuels?
oil , natural gas, coal, oil shale, tar sands
3
what are fuels?
energy stored in chemical bonds of ancient organic life.
4
What is electricity?
A secondary form of energy that is easier to transfer than fossil fuels
5
When are fossil fuels produced?
when organic materials are broken down in anearobic(little to no oxygen) environments. occurs at the bottom of deep lakes, swamps, and shallow seas
6
what nation has the most coal?
USA
7
Net energy =
Energy returned - energy invested
8
what is coal?
organic plant and animal matter that was compressed under very high pressure to form dense carbon structures
9
What is the least compressed and most compressed (more energy) coals called?
Lignite LLLeast compressed
Anthracite most compressed
10
how does peat differ from coal?
peat remains wet when broken down, not well compressed
11
What impurities does coal contain
sulfur, mercury, arsenic, and other tracd materials.
12
What does the sulfur content of coal depend on?
whether it was formed in saltwater or fresh water
13
what are oil and natural gas mainly formed from?
plankton, including algae and bacteria
14
What does natural gas consist of?
Methane(ch4), varying amounts of other volatile hydrocarbons
15
How much of the worlds energy is from natural gases?
25%
16
How much longer are the worlds natural gases expected to last for?
only 60 yrs
17
What is kerogen?
A precursor to oil, created at shallow depths by bacterial anearobic decomposition of organic matter
18
What is coalbed methane
methane from coal seams, leaks to atmosphere during mining
19
What is crude oil?
A mixture of hundreds of different types of hydrocarbon molecules. Formed 1.5-3 km underground from dead organic material buried in marine sediments
20
whats the mosr abundant fossil fuel?
coal
21
what is the precursor to coal?
peat
22
subsurface mining
Involves digging deep into the ground, and networks of tunnels are dug or blasted out to follow coal seams
23
strip mining
heavy machinery removes earth in long, horizontal strips to expose seams and extract coal. pits are refilled with the soil that was removed.
24
Acid drainage
when sulfide minerals in newly exposed rock surfaces react with oxygen and rain water to produce sulphuric acid. The acid runs off and leaches toxic metals from the rocks.
25
Why is strip mining harmful?
-health hazards for miners
-acid drainage which affects terrestrial and aquatic ecosystems
26
What is a turbine?
a rotating device that converts the kinetic energy of a moving substance, such as steam, into mechanical energy
27
What do clean coal technologies do?
focus on ridding the toxic chemicals of coal
28
when is natural "gas" a liquid?
at ambient pressures and temperature in subsurface reservoirs
29
what is technically recoverable oil?
oil that can be extracted with current technology
30
