Question

An electric utility uses a Welsh coal that has an ultimate analysis (by mass) of 84.36percent C, 1.89 percent H2, 4.40 percent O2, 0.63 percent N2, 0.89 percent S, and

7.83percent ash (non-combustibles) as fuel for its boilers. The utility is changing from the Welsh coal to a coal from overseas which has an ultimate analysis (by mass) of 67.40percent C, 5.31 percent H2, 15.11 percent O2, 1.44 percent N2, 2.36 percent S, and8.38 percent ash (non-combustibles) as fuel for its boilers. With the Welsh coal, the boilers used 20 percent excess air. Calculate the heat released, the smokestack dew-point temperature, and carbon dioxide production for 3 different amounts of excess air(20 percent, 100 percent, and 150 percent). Note: Assume S will react with oxygen and form SO2. Assume CO and CO2 are both exist in the smokestack and are in equilibrium.

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