Final answer:
The four biofuel sources suitable for biofuel production are grasses, animal fats, sugar cane, and corn. These materials are converted into ethanol and biodiesel for use as alternative transportation fuels. Despite benefits, the production of biofuels is often debated due to its impact on food supply and sustainability.
Step-by-step explanation:
The four sources for biofuels that can be selected are grasses, animal fats, sugar cane, and corn. These sources are derived from plant materials or organic waste and can be transformed into biofuels such as ethanol and biodiesel, which are used as alternative fuels for transportation.
Bioethanol is commonly created from sugar cane, especially in Brazil, where it is fermented from the juice of the plant. In the United States, it is frequently produced from the starches found in corn. Meanwhile, biodiesel can be manufactured from animal fats and certain grasses, and is recognized for its cleaner combustion profile compared to conventional diesel fuels. However, the cultivation of crops like sugar cane and corn for biofuel production is often debated due to competition with food supply and sustainability concerns.
Biofuels are considered a form of solar energy storage, as plants convert sunlight into biomass that can later be processed into liquid fuels. Despite the challenges of scaling up biofuel production, it remains an integral part of the renewable energy mix due to its potential to replace petroleum in transportation.