Figure 1: Petroleum fractionation column showing general temperatures needed to separate the crude oil, the general term for each fraction, and the common uses for each fraction. Gasoline is made from combining Light Naptha and Heavy Naptha. So, for that 1 barrel of oil, how many gallons of gasoline were produced? ____________________ How many barrels of oil would need to be refined to produce enough gasoline to fill a standard 15-gallon car gas tank? ____________________ 3 4 How does the demand of different fractions affect the total oil needed for refinement? What happens if demand for plastics drastically increases while the demand for diesel decreases? What happens if electric vehicles totally replaced gasoline ones but still drove on asphalt roads? We use materials from ALL fractions, but some fractions are in higher demand, while others are less important. Current oil demand favors finer fractions of hydrocarbons (ones closer to the top of Figure 1) like gasoline. Additional heating in secondary towers and adding catalysts can crack longer hydrocarbons into finer ones, thus adjusting yield. Thermal cracking began in the 1910’s with the explosion in popularity of internal combustion vehicles. More gasoline and diesel had to be extracted per barrel as demand overtook the 1800’s mainstays of kerosene and fuel oil. Advances in catalytic cracking and reforming began in earnest in the 1920’s and continue to be the main driver in changing yield percentages and producing new products. Efficiency of cracking has increased markedly over the decades. While 1990’s fluid catalytic cracking units often operated at about 60% efficiency, most current US refineries boast over 80% efficiency. Here are examples of an average US cracked and reformed barrel of oil from: 1990 2023 Gases: 6% 6% Light Naptha: 21% 25% Heavy Naptha: 21% 25% Paraffin Oil: 13% 10% Light Gas Oil: 17% 30% Lubricating Oil: 3% 1% Heavy Gas Oil: 15% 1% Bitumen: 4% 2% Using these modern percentages, calculate the number of gallons produced by a fractionated and cracked barrel of oil for each of the fractions. (Show all work!) Gases _____________ Light Naptha _____________ Heavy Naptha _____________ Parrafin Oil ______________ Light Gas Oil ______________ Lubricating Oil ______________ Heavy Gas Oil _____________ Bitumen _______________ ___________________ Use your answers from above to answer the following questions: How many more gallons of gasoline do you get from a cracked barrel of oil than from raw fractionation? Demand for items made of plastics is exceptionally high in the modern world. Based on the information on cracking, what side benefit would come from reducing our demand for gasoline?