The Deepwater Horizon Oil Spill Part I. Unit Conversion Why? The Deepwater Horizon oil spill (also known as the BP oil spill) began on 4/20/2010 and ended when the well was capped on 7/15/2010. The spill was devastating to the environment and economy of the Gulf of Mexico and was widely covered by the press during the summer of 2010. Most of us, however, have little real idea about the magnitude of the spill. We will explore this and other related ideas over the course of the year in Chemistry 101 and 102. The oil slick as seen from space http://en.wikipedia.org/wiki/deepwater_horizon_oil_spill The rig on fire www.sevensidedcube.net/world2010/oil-rig-e...r-horizon/ Preliminary Questions/Homework: 1. Do some research to determine how many barrels of oil were spilled before BP was able to cap the well. 2. What is the largest amount of oil ever released in a spill? Where does the Deepwater Horizon incident fit in the 10 worst oil spills of all time? 3. Imagine that the oil released in the BP spill spreads onto a land mass to a thickness of one inch. How big an area do you think this 1 inch slick will occupy? Just guess no calculation required here! You can express this as square miles, states or cities covered, etc.
4. What are some common units of volume in both the English and the metric system? 5. How do you compute the volume of a cube that measures 5 inches x 5 inches x 5 inches? What is the volume of this cube, and what would the volume units be? Write a formula relating volume to length, width, and height. 6. What land area in square miles does New London occupy? What about your home town? 7. What is the land area of the United States in square miles? What is the total surface area of planet Earth? The Problem: Use the number of barrels you found as your answer to question 1, and convert that volume to cubic miles (miles 3 ). From that, determine how many square miles that volume would cover if the height is one inch. Hints for converting cubic units: Suppose you want to convert 1 cubic foot to cubic inches. You know that there are 12 inches in a linear foot, but don t know what to do about the cubic part. The conversion is set up as follows: 1 foot 3 (12inches) x 3 ( foot) 3 = 1 x 12 3 inches 3 = 1728 inches 3
Critical Thinking Questions: 1. Determine a sequence of conversions that will enable you to convert from barrels of oil to miles 3. Look up the necessary conversion factors. To get you started: 1 barrel = 42 gallons, 42 gallons equals 168 quarts, etc Useful conversions: 1 barrel = 42 gallons, 1 gallon equals 4 quarts, 1 liter = 1.057 quarts, 1 liter = 1 decimeter 3, 1 mile = 5280 feet, 1 meter = 39.36 inches 2. Using your conversion sequence, convert the barrels spilled during the BP oil spill to cubic miles. 3. In order to determine the area in square miles occupied by a one inch thick spill, you need to be working with consistent units. So, you need to convert 1 inch to miles. Determine the conversion sequence needed and perform that conversion.
4. The formula for volume of a rectangular shape is volume = length x width x height. Suppose that you divide a volume with units of miles 3 by a height of miles. What units remain? What do these units measure? 5. Divide the volume of the oil spill in miles 3 by the height of 1 inch converted to its equivalent measure in miles. This gives the area of the spill in miles 2. What percentage of the land mass of New London does this area represent? Are you surprised? Why or why not? 6. What percentage of the land mass of your home town would be covered by this spill? 7. The thickness of an oil film that produces bright bands of color like those seen on the Gulf waters is about 0.000012 inches. If the volume of oil released by the BP spill spread out to this thickness, what area in square miles would be covered? Look up the area in square miles of New Hampshire and New England to get a good reference point for this area.
Follow-up Exercise: 1. How many million barrels of oil are consumed daily in the United States? 2. How many barrels a year is this? 3. How many barrels of oil are consumed daily worldwide? What percentage of this total is consumed in the US? 4. What is the current population of the US? The world? Calculate the percentage of human in the US. 5. Compare and discuss your answers to questions 3 and 4. 6. Convert the yearly U.S. consumption of oil in barrels to an area with a height of 1 inch, as above. What percentage of the U.S. land mass does this represent? What percentage of the total surface area of the planet?
Part II Combustion of Oil Spill Stoichiometry, Combustion reactions Why? In order to protect the sensitive Gulf shores, many techniques were used to prevent oil from reaching land, including the use of booms, chemical dispersants, and burning the surface oil as seen below. Through a combustion reaction, the atoms of oil components are transferred to the atmosphere. latimes.com Preliminary Questions/Homework: 1. Glucose, C 6 H 12 O 6, is a fuel for living organisms, much like petroleum products fuel cars, power plants, etc. Remind yourself what the reactants and products are in a combustion reaction, and give the balanced reaction for the combustion of glucose below. 2. Crude oil is a complex mixture of hydrocarbons; the exact composition depends on the source and can be analyzed to give a fingerprint of the oil. Do some background research to determine some of the most common chemical components found in crude oil. List your findings below. The Problem: You are an atmospheric scientist concerned with climate change. You want to know how much CO 2 will be released to the atmosphere by burning the oil released during the Deepwater Horizon incident. For this exercise, assume that 4.9 million barrels in total were released. Assume that the composition of the oil on the surface of the ocean is as follows in the table below. Assume that 75% of the surface components are burned. NOTE: This is a greatly simplified representation of the actual components. The total does not add up to 100% because some gases found in crude oil would already have entered the atmosphere, and the heaviest tarry components would sink to the sediments.
Chemical Formula Chemical name Density g/ml % of total oil C 5 H 12 Pentane 0.626 8 C 6 H 14 Hexane 0.655 8 C 8 H 18 Octane 0.703 10 C 10 H 22 Decane 0.730 8 C 12 H 26 Kerosene 0.750 11 C 24 H 50 Heating oils 0.899 25 C 6 H 6 Benzene and aromatics 0.877 20 Critical thinking questions: 1. What information do you need to determine the amount of CO 2 released to the atmosphere? Explain the steps you will use. 2. Give balanced equations for the combustion of each hydrocarbon listed in the table.
3. In case you were feeling stumped on question 1, here are some hints to get you started: a. Multiply the total number of barrels release by the percentage of each component to figure out barrels of each component. b. Multiply these numbers by 75%, satisfying the assumption above that 75% of all surface components were burned. c. Convert each of these amounts in barrels to milliliters. d. Use the densities given to determine how many grams of each component you have. e. By stoichiometric analysis using your balanced equations above, you can determine the mass of CO 2 produced by combusting each hydrocarbon. f. The total mass of CO 2 is just the sum of the mass produced by burning each component. Show your work below and determine the total mass of CO 2 that would be produced by combusting the components of the BP spill.
Additional problems: 4. Use the chart above for the composition of crude oil. Assume that the US uses 20 million barrels of oil daily and these barrels are completely combusted. How much CO 2 is released annually to the atmosphere by using this oil? 5. The total mass of the atmosphere is about 5 x 10 18 kg. By what percent does the mass of the atmosphere increase over a year from the combustion of 20 million barrels of oil daily in the US? Assume no other inputs or withdrawals of matter to the atmosphere. 6. How is some of the atmospheric CO 2 removed by natural processes?