Question

Which technology utilizes electric charges to remove particulate matter from industrial flue gases?

• A. Flue Gas Desulfurization (FGD)
• B. Selective Catalytic Reduction (SCR)
• C. Electrostatic Precipitators (ESP)
• D. Thermal Oxidizers

Hint:

• Electrostatic Precipitators (ESPs) use electrostatic forces to remove particulate matter from gas streams.
• Particles are electrically charged and then collected on oppositely charged plates.
• FGD systems target SO$_2$.
• SCR systems target NO$_x$.
• Thermal oxidizers target VOCs and combustible gases.

Answer 1

The Correct Option is C

The technology that uses electric charges to remove particulate matter (PM) from industrial flue gases is Electrostatic Precipitators (ESP). How ESPs work:
Option (A) Charging of Particles: The flue gas containing particulate matter passes through a strong electric field created by high-voltage discharge electrodes. These electrodes generate ions (corona discharge) that attach to the particles, giving them an electrical charge (usually negative). 
Option (B) Collection of Charged Particles: The charged particles are then attracted to and collected on grounded or oppositely charged collection plates. 
Option (C) Removal of Collected Particles: The accumulated layer of particles on the collection plates is periodically removed (e.g., by rapping or washing) and falls into hoppers for disposal. ESPs are highly efficient in removing fine particles and can handle large volumes of gas. 
Let's look at other options: 
Option (a) Flue Gas Desulfurization (FGD): Technologies (like wet scrubbers, dry sorbent injection) used to remove gaseous sulfur dioxide (SO$_2$), not primarily particulate matter (though some PM might be incidentally removed). 
Option (b) Selective Catalytic Reduction (SCR): A technology used to reduce emissions of gaseous nitrogen oxides (NO$_x$) by reacting them with ammonia or urea over a catalyst. 
Option (d) Thermal Oxidizers: Used to control gaseous volatile organic compounds (VOCs) and other combustible air pollutants by incinerating them at high temperatures. 
Therefore, Electrostatic Precipitators are the technology that fits the description. \[ \boxed{\text{Electrostatic Precipitators (ESP)}} \]