Question

A boiler in an industry, located where high plume rise is expected, releases flue gas with fine particulate matter. Which one of the following options is most suited and efficient if this particulate matter is intended for reuse?

• A. reduce stack height and increase stack diameter
• B. use of wet collectors
• C. use of flue gas desulfurization (FGD)
• D. use of electrostatic precipitator (ESP)

Hint:

- ESP is best for fine particulate matter removal and reuse.
- Wet scrubbers are effective but unsuitable for reuse (slurry formed).
- FGD is only for gaseous SO$_2$ control.

Answer 1

The Correct Option is D

Step 1: Identify the pollutant type.
The problem specifies fine particulate matter in flue gas. Control devices should be chosen accordingly.
Step 2: Assess each option.
- (A) Reducing stack height does not remove particulate matter, it only affects dispersion. Not suitable. - (B) Wet collectors (scrubbers) can capture particulates, but they mix particles with water → recovery and reuse becomes difficult. - (C) Flue gas desulfurization (FGD) is for SO$_2$ removal, not particulates. Wrong choice. - (D) Electrostatic precipitators (ESP) are specifically designed to remove fine particulates (PM$_{2.5}$, PM$_{10}$) by charging them electrically and collecting on plates. Importantly, the collected dust remains dry and can be reused.
Step 3: Conclusion.
Since reuse of particulate matter is intended, only ESP allows efficient dry collection of fine particles. Final Answer: \[ \boxed{\text{(D) use of electrostatic precipitator (ESP)}} \]