Evaluation Questions: Biodiesel Energy Source

A new biodiesel plant plans to use used cooking oil as its main raw material. Based on analysis, the oil has a Free Fatty Acid (FFA) content of more than 5%. Which production method is the most technically and economically suitable for this condition?

• Transesterification with base catalyst (NaOH)

• Transesterification with enzyme catalyst (Lipase)

• Two-step transesterification: acid catalyst followed by base catalyst

• Esterification with base catalyst

In the context of the Second Law of Thermodynamics, the biodiesel purification process (washing with water and drying) is naturally inefficient. What thermodynamic phenomenon mainly causes this inefficiency?

• Violation of the Law of Energy Conservation

• Decrease of total system entropy

• Irreversible increase in entropy

• Inability to reach absolute zero temperature

A researcher wants to produce biodiesel from microalgae. What is the main economic challenge that limits its large-scale commercialization?

• Low oil content in algal biomass

• Inability of algae to grow in seawater

• Very high cost of cultivation, harvesting, and oil extraction

• Incompatibility of algal oil with transesterification process

In the transesterification reaction, glycerol is produced as a by-product. Which of the following is a strategy to improve the thermodynamic energy efficiency of the process using glycerol?

• Disposing of glycerol to the environment because it is useless

• Selling crude glycerol as a final product

• Using glycerol as a feedstock to produce hydrogen or methanol, reducing external energy needs

• Mixing glycerol back into biodiesel to increase its volume

What is the main difference between first-generation and second-generation biodiesel feedstocks?

• First generation uses vegetable oil, while second generation uses animal fat

• First generation uses edible oils, while second generation uses non-edible oils and waste materials

• First generation uses base catalyst, while second generation uses acid catalyst

• First generation is produced in Europe, while second generation is developed in Asia

In biodiesel production using supercritical methanol, why is a catalyst not required?

• Because supercritical methanol is inert and does not react

• Because vegetable oil already contains a natural catalyst

• Because under supercritical conditions, methanol acts as both a highly reactive reactant and solvent

• Because the reaction occurs at very low temperatures, so the catalyst is inactive

If a biodiesel factory only has access to high-quality crude palm oil (CPO) with low FFA (<0.5%), what is the main consideration in choosing a catalyst for maximum economic efficiency?

• Choose an enzyme catalyst because it is the most eco-friendly

• Choose an acid catalyst to save on alcohol cost

• Choose a base catalyst (like NaOH) because it is cheap and reacts fast

• Choose to not use any catalyst at all

In the total exergy equation, the physical exergy component (Ex physical) is mainly influenced by which process variables?

• Mass flow and chemical potential

• Flow velocity and height

The “food vs. fuel” issue is mainly related to which generation of biodiesel?

• First Generation

• Second Generation

• Third Generation

• All Generations

Compared to fossil diesel, the main advantages of biodiesel that encourage its adoption are, except...

• Renewable nature

• Lower greenhouse gas emissions

• Higher heating value per liter

• Biodegradable (can naturally decompose)