Question

Do Problem 4.26, Part (a) only in the textbook: Gas absorption org as scrubbing isa commonly used method for renome ronmentally able species from waste gases in chemical manufacturing and combustion processes The waste gas is contacted with a liquid solvent in which the potential pollatants are Highly soluble and the ocher species in the waste gas are relatively insoluble. Most of the pollutants go isto solution and emerge with the liquid effluent from the scrubber, and the cleased gas is discharged to the atmosphere. The liquid effuent may be discharged to a waste lagoom or subjected to further treatment to recover the solvent and/or to convert the pollutant to a species that can be released safely to the environment A waste gas containing SO; (a precurser of acid rain) and several other species (collectively designated as A) is fed to a scrubbing tower where it contacts a solvent (B) that absorbs S0. The solvent feed rate to the tower is 1000 L/min. The specific gravity of the solvent is 1.30. Absorption of A and evaporation of B in the scrubber may be neglected Effluent lqud 1, 50 incharge to mae on or process further The gas in the scrubber rises through a series of trays (metal plates perforated with many small holes) and the solvent flows over the trays and through downcomers to the trays below. Gas bubbles emerge from the holes in each tray and rise through the covering liquid, and SO; diftuses out of the bubbles and into solution. The volumetric Bow rate of the feed gas is determined with an orifice meter, with a differential mercury manometer being used to measure the pressure drop across the orifice Calibration data for this meter are tabulated bere: himm) enin) 100 200 300 400 142 204 247 290 The molar demity of the feed gas may be determined from the formla mol ) 122P(atm TOk) where P and T are the absolute pressure and temperature of the zas Aa is used to measure the SO, concentration in the inlet and outlet gas streams SO in the sampled is absorbed in a solution across which a fixed voltage is applied, and the moke fractioe of SO, in the gas is determined from the resulting current. The calibeation curve for the analyzer is a straight line on a semilog plot of yimol SOyimol total) verus R (analyzer reading), which passes through the following points og sale) (rectangular scale) 20 0.00166 0.1107 The following data are taken -75 F P 150 pig Morifice meter) 210 mm R(SOn analyzer) 824 R(SOp analyner)- 116 (outlet gas) (feed gas) SO, mole fractions of the gas streams and the mass Bow rates and SO, mass fractions of the liquid streams Show that the scrubber has zero degrees of freedom (a) Draw and completely label a process Dowchart laclude in the labeling the molar tow rates and Make sure to read thru the entire problem description

Answer 1