B, C, E
Clarify Question
• What is the key concept addressed by the question?
o This question addresses biofuels from algae.
• What type of thinking is required?
o This question is asking you to take what you already know and apply it to this unfamiliar situation.
Gather Content
• What do you already know about biofuels from algae?
o Biofuels produced from microalgae have several advantages over petroleum-based fossil fuels. They are renewable as long as carbon dioxide can be fixed into biomass by photosynthesis. They are more environmentally friendly than fossil fuels, given that carbon in the fuel is derived from atmospheric carbon dioxide, a greenhouse gas that contributes to climate change. The production of biodiesel from microalgae can also be combined with processes such as wastewater treatment or coupled to carbon dioxide capture systems of fossil fuel burning industrial plants.
o A variety of techniques can be used to harvest the lipids from the algae, and this is one of the most expensive parts of algal biodiesel production. Once the lipids have been isolated from the algae, chemical treatments separate the glycerol from the fatty acid chains in the triglyceride. Further refinement yields a biodiesel product.
Choose Answer
• Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?
o In the proposed biofuel system, would kelp fronds provide habitat for endangered sea otters? No. Biofuels are made from microalgae in ponds or tanks, not kelp in the ocean.
o Is a benefit of biofuel that it doesn't need to be burned to provide energy? No, it still needs to be burned like any other fuel.
o Is a benefit of biofuel that the algae can be filtered from the water and used for fuel without refinement? No. The lipids need to be refined from the algae, and this expensive procedure limits the efficiency of the process.
o Is a benefit of biofuel that it contributes less carbon to the atmosphere overall? Yes. Since the algae first captures carbon from the atmosphere (CO2 that it uses to grow), the overal release of carbon from burning the fuel is balanced.
o Is a benefit of biofuel that it is a renewable resource? Yes, unlike fossil fuels, we can grow more algae.
o Is a benefit of biofuel that the system could be paired with wastewater treatment? Yes, and could also be paired with an industrial carbon capture system.
Reflect on Process
• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
o The question required you to take what you already know and apply it to this unfamiliar situation.
o Did you recognize that the benefits of algae biofuels are that they are renewable, they release less carbon overall, and they can be paired with wastewater treatment?