Injecting limestone powder during pulverized coal combustion in boilers serves to ______________ the flue gases?
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Answer: A. Reduce SO2 content in
Explanation
Pulverized coal combustion releases large quantities of sulfur dioxide gas into furnace flues. Injected limestone calcines into reactive calcium oxide at high furnace temperatures. Calcium oxide reacts chemically with sulfur dioxide to form solid calcium sulfate particles. Thermal power plants implement flue gas desulfurization to control harmful acid rain emissions. Limestone injection multistage systems provide an economical method for in furnace sulfur capture. Solid reaction products are subsequently trapped by particulate control devices downstream.
Environmental regulations strictly limit sulfur dioxide emissions from fossil fuel power stations. This emissions control technology helps protect forests and aquatic ecosystems from acidification. Power plant operators optimize limestone feed rates to maximize sulfur removal efficiency. Options B and C describe incorrect chemical and physical phenomena unrelated to sulfur capture. Catalytic conversion of sulfur dioxide to sulfur trioxide requires specialized catalytic reactors. Limestone injection does not intentionally raise the acid dew point of combustion gases.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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