A power plant produces a flue gas with a mass flow rate of 2 million pounds per hour. Of that, 150,000 lb/hr is water vapor, and 15,000 lb/hr is SO₂. All the other gases that are not SO₂ or water have an average molecular weight of 28.

(a) Calculate the concentration of SO₂ in the flue gas in ppm(v) (dry basis). Regulations require that 92% of the SO₂ be captured, and a limestone scrubber will be used to do the job. Assume that scrubber exit gases are saturated with water vapor at 125 degrees Fahrenheit.

(b) Estimate the SO₂ concentration of the exiting gases in ppm(v) (dry basis). Assume that there is no HCl in the gases, and that the limestone is 96% CaCO₃ (with a MW of 100) and 4% inerts. The alkalinity supplied will be 1.12 times the stoichiometric ratio.

(c) Calculate the limestone feed rate, lb/hr. Assume that the flow rate exiting the scrubber is 800,000 acfm and the scrubber pressure drop is 10 in. H₂O. Calculate the fan power used just by the scrubber, in hp.