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.