Question

Arrange the following waste/materials in increasing order of their energy content in terms of Higher Heating Value (HHV) in kJ/kg: A. Natural Gas B. Rubber C. Plastics (mixed) D. Mixed paper E. Mixed/Waste food

• A. A, C, B, D, E
• B. E, D, B, C, A
• C. E, D, C, B, A
• D. E, B, D, C, A

Hint:

Higher carbon content and lower oxygen/moisture = higher HHV. Natural gas has the highest; food waste the lowest due to high moisture.

Answer 1

The Correct Option is B

Step 1: Concept
Higher Heating Value (HHV) of different waste materials.

Step 2: Meaning
HHV is the total energy released when a fuel is completely combusted, including the latent heat of water vapour condensation.

Step 3: Analysis
Approximate HHV values (kJ/kg):
• Mixed/Waste food (E): $\sim$4,000--8,000 (lowest, high moisture content)
• Mixed paper (D): $\sim$12,000--17,000
• Rubber (B): $\sim$32,000--37,000
• Mixed plastics (C): $\sim$33,000--40,000
• Natural gas (A): $\sim$52,000--55,000 (highest) Increasing order: E $<$ D $<$ B $<$ C $<$ A.

Step 4: Conclusion
In increasing HHV order: E, D, B, C, A. Final Answer: (B)