Biorenewable Enhancement Problems Bank
General:
1. Using the information below and assuming the soybeans are composed of protein, oil and hulls, how much would a bushel of soybeans weigh?
Soy protein = 48 lbs
Soy oil = 11 lbs
Soy hulls = 1 lbs
2. A farmer has 80 bales of switchgrass with an average volume of 1.85m3 loaded on a flatbed of a semi. Each bale can deliver 3.6 GJ/m3 of energy. How many joules of energy would this semi load of switchgrass potentially produce? BC
3. If the farmer above can harvest 200 bales from 10 acres of land, how much energy is produced per acre?
4. The same farmer is willing to sell each bale for $55. BC
a. How much money will the farmer receive for the semi load of switchgrass?
b. How much does each joule of energy cost at this point?
5. How many barrels of crude oil would be saved by this one semi load of switchgrass given there are 5.8 x 106 BTUs in a barrel?
6. Given 80% efficiency in production, how many gallons of ethanol will the semi load of switchgrass in question 5 produce?
7.
Biodiesel:
8. Petroleum diesel contains 1.29 x 105 BTU/gal compared to 1.18 x 105 BTU/gal for biodiesel. How many gallons of B100 biodiesel does it take to get the same number of BTUs? BC
9. If standard #2 petroleum diesel cost $2.75/gal. What would biodiesel have to sell for to get the same amount of BTUs in 10 gallons of petroleum diesel? BC
10. Forty billion gallons of petroleum diesel is consumed in the United States each year. If the United States would legislate that all diesel be B20,
a. How many acres of soybeans (a favorite oil) would have to be grown to meet this requirement?
b. Could the United States realistically meet this goal?
c. How could Iowa’s soybean crop contribute and/or be affected?
d. Explain/discuss in your group/class the pros and cons of your answers b and c.
Do some research to find out how many gallons of oil soybeans produce per acre (48-90), efficiency of biodiesel production (90%-100%) and how many acres of soybeans are grown in US (75 mil)? In Iowa (10 mil)?
Fermentation-Ethanol
11. A 80m3 of corn stover contains 61 GJ of energy and is sold for $90. Calculate the price of energy per GJ.BC
12. Gasoline produces 1.15 x 105 BTU/gal. Ethanol produces 34% less energy. How many BTUs does a gallon of ethanol produce?
13. The chemical formula for the reaction where glucose converts to ethanol and carbon dioxide is:
C6H12O6 è 2 C2H5OH + 2 CO2
Glucose Ethanol Carbon Dioxide
a. Given the molar ratio of ethanol to carbon dioxide, how many grams of ethanol are produced if 28 grams of carbon dioxide is released?
b. The density of ethanol is 0.79 g/mL. Calculate the volume of ethanol produced from this reaction.
14. 200 grams of glucose are completely reacted in the above reaction.
a. How many milliliters of ethanol are produced?
b. How many grams of carbon dioxide are given off?
Fermentation Lab:
Additional Analysis:
1. Graph the entire class’ data. By this I assume you mean graph the data for each flask and put the seven graphs on one piece of paper…perhaps color coded.
2. Which cups indicated the fastest rate of reaction? I am not sure what you mean by this. I assume the graphs will be roughly logistic in nature (?). The graph with the interval of steepest slope? I think this question is a little vague and could be open to interpretation by the students. That said, I think this is GOOD!!! Students should discuss the different ways this question can be interpreted and decide as a class on the meaning of “fastest rate of reaction” and then write a clear definition of their meaning. Do other classes come up with the same definition?
Questions:
1. What are the main chemical components in this reaction? reactants to products
2. As the exercise is set up, which of the components is likely responsible for the change in mass?
3. Assuming no other component caused the change in mass, how many grams of the second product is produced?
4. What is the chemical and/or commercial name of this second product?
5. Research and discuss the economic importance of this second product.
6. How does the addition of enzymes influence the reaction?
7. Research which group of enzymes would be responsible for affecting/influencing the reaction.
8. What is the purpose of using saliva as a substitute for commercial enzymes?
Questions: Here are some other possible questions.
1. In experiments we often have variables and constants. What is meant by these terms.? What are the variables in this experiment. What are the constants? What are some other things you could change that might affect the outcome (yield) and how would you design an experiment to test the effect of these changes? (for example water temperature, water volume.)
How do you think one of these changes might affect the outcome?
2. I think having students calculate rates of change for each interval would also be a good exercise. Assuming they produce piecewise linear graphs this could be linked to the exercise of calculation of slope in their math class and give a good example of ways in which slope is useful. In fact, if all science students in a class are in the same math class the data could be carried to the math class for an activity and continued discussion there. This could also lead to a discussion of units and how the units themselves give meaning to the calculations.
3. Suppose we let the experiment run for a week? How do you think your measurement at that time would compare with your last measurement? After a year?
4. Why do we poke holes in the parafilm? What might happen if we did not?
5. Suppose you were consulting for a company that wants to product this product. Based on these experiments, what advice would you give them?