Question

Combustion of a hazardous waste material produces 1000 m3 offlue gas per minute at 405 °C and 105 Pa (1 atmosphere) pressure.The concentration of sulfur dioxide in the flue gas is 350 ppm. A spray drier using Ca(OH)2 will be used to achieve 70% collection efficiency of sulfur dioxide as calcium sulfate. Achieving this will require an excess of reagent over the stoichiometric quantity of 30%. Based on these data: a. Determine the required feed rate of Ca(OH)2 in kg h-1 to the spray drier. (20 marks) b. Estimate the total mass of calcium sulfate produced per hour by the spray drier if its water content is 10% by mass. (5 marks)

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