Why was the previous recovery method said to be carbon-intensive?

• A. It used solvents only
• B. It required extremely high temperatures
• C. It relied on renewable energy
• D. It generated no emissions

Answer: (B)

Carbon intensity is about how much energy a process uses and where that energy comes from. A recovery method that operates at extremely high temperatures needs a lot of energy to reach and maintain those temps. If that energy comes from burning fossil fuels, it releases substantial CO2, making the process carbon-intensive. High heat environments also tend to have energy losses, which adds to emissions per unit of product. The other options don’t fit because using solvents doesn’t automatically imply high carbon emissions, renewable energy would reduce emissions, and generating no emissions would indicate very low, not high, carbon intensity.