EPS219 Energy and the Environment

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.