EPS219 – Energy and the Environment
Homework#3 – Due in class, Thursday, February 5, 2015
1) (10 pts) Ch7, Q#1: What are the reasons for the decrease in U.S. crude oil
production since 1970 [up until the recent surge]?
The availability of low-cost oil reserves has decreased. We have begun to use up
our easily retrieved oil reserves (i.e., there is oil left, but it is more costly to
produce).
2) (5 pts) Use the Web to find an estimate for the amount of oil in the Arctic
National Wildlife Reserve.
USGS estimates are in the 6-14 billion barrel range.
3) (5 pts) Ch7, P#2: If all our needs for oil were to be provided by that available
from the estimated reserves located in the Arctic National Wildlife Reserve, how
long would that supply last, assuming no growth in demand?
The US uses about 7 billion barrels per year, which means that all the oil of the
Arctic National Wildlife Refuge could, at most, provide 1-2 years of our oil.
4) (10 pts) Water is abundant and can be used as a source of hydrogen (which
burns and can be a useful fuel). Why don’t we use water as a major source of
energy?
More energy is needed to split the water into hydrogen and oxygen than is
gotten back from burning the hydrogen.
5) (10 pts) Given the information about the boiling and melting temperatures of
common alkanes, explain why butane is a good choice for the fuel in pocket
lighters? Why is butane in a liquid form inside the lighter?
You want a fuel that is a gas at standard temperature and pressure (surface
conditions), but can easily be stored as a liquid. Butane meets this requirement
because it has a boiling temperature of 0°C (at standard pressure), but with a
little bit of pressure, is compressed into a liquid. So, it is a compact liquid in your
lighter, but when it is let our, converts instantly into gas.
6) (10 pts) Hydrocarbons are continuously being formed underground by
natural processes. Explain why they are considered non-renewable energy
sources.
The process of converting buried organic matter into simple hydrocarbons is
very slow (millions of years). We are using up the hydrocarbons much faster
than they are forming, making them a non-renewable source in practical terms.
7) (10 pts) Explain how the end products of burning hydrocarbons can vary
among carbon dioxide, carbon monoxide, and carbon soot.
The end product of the combustion of hydrocarbons depends upon the amount
of oxygen available. If there is sufficient oxygen, the end products of combustion
are water and carbon dioxide. However, if less oxygen is available, then carbon
monoxide or even pure carbon soot can be produced.
8) (10 pts) In relation to hydrocarbons, explain the difference between
“cracking” and “fracking.”
Cracking refers to the process of chemically breaking down the complex organic
molecules within plant and animal matter into simpler molecules such as simple
hydrocarbons. Fracking is short for “hydrologic fracturing,” which is the process
of retrieving natural gas from underground layers of shale.
9) (10 pts) Explain why solar panel technology needs to be developed in tandem
with battery technology (as discussed in the “Energy Sources” article).
The sun doesn’t always shine, so a way of storing energy (when the sun does
shine) is needed to provide a steady supply of energy.
10) (10 pts) Even though there are no coal power plants that currently capture
and sequester CO2 underground as a way to remove the CO2, explain why the
technology of pumping CO2 underground has already been in use for decades
(as discussed in the “Can Coal Ever Be Clean?” article).
Carbon dioxide captured from combustion has been pumped underground to
create pressure that helps to push oil out of the ground, increasing the efficiency
of the yield of an underground petroleum reservoir.