Question

Statement (1): The overall combustion efficiency of a fuel oil-based plant is less as compared to that of a coal-burning plant.

Statement (II): Fuel oils contain a comparatively larger percentage of hydrogen, which produces more moisture per kg of fuel burnt.
1. Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
2. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
3. Statement (I) is true but Statement (II) is false
4. Statement (I) is false but Statement (II) is true

Answer 1

Correct Answer - Option 1 : Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Explanation:

Combustion efficiency:

• it is defined as the ratio of heat released by the fuel to the heat input by the fuel.
• it is generally high in FBC systems.
• Combustion efficiency is affected by fuel type, bed temperature, gas velocity, and excess air levels.
• Combustion efficiency increases with fuel volatile matter content and bed temperature.
• The overall combustion efficiency of a fuel oil-based plant is less as compared to that of a coal-burning plant.

Hence statement I is correct.

• percentage of hydrogen in fuel oil and coal is 10.99 and 5 respectively.
• Fuel oils contain hydrogen in a large percentage which on heating reacts with oxygen produce moisture content in fuel which drops the calorific value of fuel oil.

Hence statement II is also correct.

∴ the correct answer is option 1.