Problem Problem Set in i n Gas Absorption
1. 9000 L/min L/min of of a gas mixtur mixture e containi containing ng 22% 22% N ! " #$% Air b mole s&all be treate' in a pac(e' absorber using No. 1 plastic )ntalox sa''les. 90% of t&e ammonia is to be absorbe' using a *ater rate *&ic& is 1.+ times t&e minimum. ,perating con'itions con'itions are 1.+ atm an' !0 o- . a. etermine etermine t&e to*er to*er 'iamet 'iameter er.. a. eig&t of Pac(ing Pac(ing if Ga $0 (mols/&rm!atm (mols/&rm!atm using N,G ealuate' ealuate' b log mean met&o' an' -olburn 34uation ! 2. 10 m /min of a gas mixture containing 1+% N !" $+% Air b mole s&all be treate' in a pac(e' absorber using No. 2 rasc&ig super ring. $0% of t&e ammonia is to be absorbe' using a *ater rate *&ic& is 2 times t&e minimum. ,perating con'itions con'itions are 1.+ atm an' !0 o5 . a. etermine etermine t&e to*er to*er 'iamet 'iameter er.. b. eig&t eig&t of Pac(ing ac(ing if G 0.$ 6S) units7 using N,G ealuate' b log mean met&o' an' -olburn 34uation !. 1+ m!/min m!/min of a gas gas mixtur mixture e containi containing ng 1+% S, 2" $+ % Air b mole s&all be treate' in a pac(e' absorber in or'er to recoer $+ % of t&e S, 2 . 8&e *ater rate is 2+ % greater t&an t&e minimum. ,perating con'itions are are 1 atm an' o 20 - . etermine t&e to*er 'iameter if t&e pac(ing use' is a. 2+ mm meta metalli llic c :asc :asc&ig &ig :ing :ings s b. eig&t of Pac(ing Pac(ing if Ga $0 (mols/&rm!atm (mols/&rm!atm using N,G ealuate' ealuate' b log mean met&o' an' -olburn 34uation ! ;. 12 m /min of a gas mixture containing 22% N ! " #$ % Air b mole s&all be treate' in a pac(e' absorber in or'er to recoer 9+ % of t&e N ! . 8&e *ater rate is 1+ % greater t&an t&e minimum. ,perating con'itions are are 1 atm an' o 20 - . a. etermine t&e to*er to*er 'iameter if t&e pac(ing use' is 1+ mm Pall rings b. eig&t of of Pac(ing Pac(ing if a a $0 6S) units7 units7 using N,G ealuate' ealuate' b log mean met&o' an' -olburn 34uation +. A pac(e' pac(e' column 6 ;0 cm7 cm7 *ill treat treat 9000 L/min of a gas gas containing containing 1+% o N! " $+% Air at 1.+ atm an' !0 - . Pure *ater enters t&e top of t&e column. 90% recoer of N is 'esire' using No.1 plastic )ntalox sa''les. 5in' 5in' a.
a. es a li4ui' to gas mass ratio of 21 an' t&e use of 1in Pall rings. -alculate a. 8&e gas mass elocit at ?oo'ing b. At +0% safet factor for ?oo'ing" calculate t&e pressure 'rop an' to*er 'iameter c. eig&t of t&e to*er using all met&o's if G 0.#+ 6S) units7 assuming an e4uilibrium cure ;+x 10.S,2 is being absorbe' in a to*er using pure *ater at 20 o- an' 1 atm abs pressure. 8&e fee' rate is =+0 (g/& an' contains ! mole% ammonia in air. 8&e process 'esign speci>es a li4ui' to gas mass ratio of 21 an' t&e use of 1in Pall rings. -alculate a. 8&e gas mass elocit at ?oo'ing b. At =0% safet factor for ?oo'ing" calculate t&e pressure 'rop an' to*er 'iameter c. eig&t of t&e to*er using log mean met&o' an' -olburn 34uation if G 0.$ 6S) units7 assuming an e4uilibrium cure ;0x
