Name a technique to reduce sulfur dioxide emissions from a coal fired power plant.

• A. Electrostatic precipitation
• B. Postcombustion scrubbing
• C. Precombustion methods
• D. Fuel switching

Answer: (C)

Reducing sulfur content before combustion lowers the amount of sulfur that can form sulfur dioxide in the boiler. By cleaning or desulfurizing the coal, you feed the furnace with fuel that has less sulfur, so the chemical reactions produce much less SO2 in the flue gas. This source-reduction approach is effective because it tackles the problem at its origin, often reducing the need for extensive downstream gas cleanup. While methods that remove SO2 after combustion (like scrubbing) or strategies such as switching to a lower-sulfur fuel can also reduce emissions, precombustion methods directly cut the amount of sulfur that enters the combustion process, making them a straightforward and impactful technique for controlling SO2 from a coal-fired plant.