Washing the Biodiesel: Once the biodiesel has separated in the separatory funnel, the bottom portion will contain glycerin, one of the two products of the reaction. It should be a darker caramel-color phase, as shown in Figure 1 (left). The lighter phase at the top is the biodiesel. It still has some impurities in it, including KOH and unreacted methanol and mono- and di- glycerides that need to be washed out.

Biodiesel production:
Your report must include the follow sections.
â— Introduction: Discuss what questions this experiment addressed, and why they are interesting/important.
a. What is biodiesel? What types of molecules are in biodiesel?
b. What is the difference between biodiesel and vegetable oil? Why can we not use vegetable oil directly in diesel engines?
c. How much biodiesel is currently produced in the United States?
d. What are the most commonly used crops for biodiesel in the United States, Europe, and Asia? What has determined these choices?
â— Methodology: Explain what methods were used in the laboratory to answer the questions being addressed.
a. Explain what would happen if you did not add enough KOH, or if you added too much.
â€¢ Results: Present the data that was collected in the laboratory.
â€¢ Post-Lab Questions: Unlike in the previous report, there will be a separate section in this report for you to answer the post-lab questions. Calculations do not have to be in paragraph form.
â€¢ Discussion: Discuss the implications of the data you collected.
a. If your biodiesel did not have the characteristics you expected, provide possible explanations why.
b. What are the advantages and disadvantages of biodiesel compared to fossil diesel?
c. Besides algae, what other crops would produce biodiesel more efficiently than the crop used currently? Which one would you recommend for the United States, and why?
â€¢ Conclusion: Provide a summary of your findings and their importance. Also suggest one or two future research questions.
â€¢ Authorsâ€™ Contributions: Explain what each member of the team did during the experimental portion of the lab and in writing the report.
â€¢ References: Include an alphabetical list of resources you cited in the text.
â€¢ Figures with Captions: Either the Results or Discussion section should have at least one graphical view of data and/or its implications.

Post-Lab Questions:
1. As you have probably measured, the cloud point of biodiesel is well within typical winter- time temperatures, which makes cold weather one of the main problems for using biodiesel. B20, which is a mixture of 20% biodiesel and 80% diesel, is often recommended during winter months.
The cloud point of fossil-derived diesel fuel is about -15Â°C. When you mix biodiesel with fossil diesel, the cloud point temperature increases by about 0.15Â°C for each 1% of biodiesel in the mixture. Based on that information, what is the expected cloud point of B20? Would this be suitable to use in the winter in a very cold place in America?
2. Biodiesel can be made from any vegetable oil or animal fat. Below are U.S. production levels of the top vegetable oils in 2016/2017 (FAO and US Department of Agriculture. "Production of Vegetable Oils in The United States in 2016/2017 (in Million Pounds), by Oil Type." Statista).

Vegetable Oil Production (Million Pounds)
Soybean          22,560
Corn                5,550
Canola             1,932
Cottonseed       545
Sunflower       499
Linseed          215
Safflower          75
Olive                11
Total Vegetable Oil 31,387

a. If the density of oil is 7.6 pounds per gallon, and you get 1 gallon of biodiesel for every gallon of oil, how many billion gallons of biodiesel could be produced from these sources?
b. According to the Energy Information Administration, the U.S. consumed 58.15 billion gallons of low- and ultra low-sulfur No. 2 diesel in 2017. What percentage of that could have been supplied if all the vegetable oil in the U.S. was used to produce biodiesel?
3. What must you be particularly careful about if you want to use spent cooking oil to make biodiesel, and why?
4. Burning 1 gallon of diesel fuel emits 22.2 pounds of CO2 into the atmosphere. A well- to-wheel analysis of biodiesel by the National Renewable Energy Laboratory found that replacing petroleum diesel with biodiesel reduces net CO2 emissions by 79% (Sheehan, et al, Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus, Report from NREL for USDOE Office of Fuel Cycle and Development).
a. How many billion pounds of CO2 could have been saved in 2017 by switching as much of our diesel fuel as possible to biodiesel?
b. In 2017, the U.S. emitted roughly 5143 million metric tons of CO2. A metric ton is 2204 lbs. What percentage of our total emissions could have been saved by using as much biodiesel as possible? Does this percentage seem small or large to you?
5. Biodiesel is often considered as carbon-neutral, yet in the previous question, it was stated that biodiesel only offers a 79% savings in carbon. What are some of the aspects of biodiesel production that could make it not carbon-neutral?

Washing the Biodiesel: Once the biodiesel has separated in the sepa...