1. It is desire desired d to absorbed absorbed 90% of of the aceto acetone ne in a gas gas containi containing ng 1.0 mol % acetone in air a countercurrent stage tower. tower. The total inlet gas ow to the tower is 30.0 kg mol/h, mol/h, and the total oerate isothermall! isothermall! at 300 " and a total ressure of 101.3 k#a. The e$uilibrium relation relation for the acetone in the gasli$uid is !&'.(3 ). *etermine the number of theoretical stages re$uired for this searation. +eeat but use the "remser anal!tical e$uations for countercurrent stage rocesses.
'. relati-el relati-el! ! non-olatile non-olatile h!droca h!drocarbon rbon oil contain contains s .0 mol % roane roane and is being stried b! direct direct suerheated steam in striing tra! tower to reduce the roane content to 0.'%. The temerature is held constant at '' " b! internal heating in the tower at '.0'10 ( #a ressure. total of 11.' kg mol of direct steam is used for 300 kg mol of total entering li$uid. The -aorli$uid -aorli$uid e$uilibria can be reresented b! !&'(), where ! is mole fraction roane in the steam and ) is a mole fraction rane in the oil. team can be considered as an inert gas and it wil nt condense. #lot the oerating and e$uilibrium lines and determine the number of theoretical tra!s is needed.
3. 230 o oints nts gas co conta ntains . .0 mo mol
45 3 and its ammonia is reduce reduce 0.( mol mol
in a acked absortion tower at '93 " and 1.013
×
10( #a. The inlet
ure water ow is 6.0 kg mol/h and the total total is inlet gas ow is (7.6 (7.6 kg mol/h. The tower diameter 0.77 m. the the 8lm masstransfer coecients coecients are k!a &0.0739 kg mol/sm 3moll fraction and k )a&0.19 kg mol/ sm 3mol fraction. :sing the design methods for dilute gas mi)tures, do as follows; a.
. In an e)erimen e)erimental tal stud! stud! of the absortio absortion n of ammonia ammonia b! water water in a wetted wetted wall column, the -alue of " = was found to be '.7(
×
10 kmol/m'sk#a. t
one oint in the column, the comosition of the gas and li$uid hases were 6.0 and 0.11( mole 45 3, resecti-el!. The temerature was 300 ", and the total ressure was 1 atm. >ight!8-e ercent of the total resistance to mass transfer was found to be in the gas gas hase at 300 k, ammonia ammonia water solutions follow 5enr!?s law u to ( mole ammonia in the li$uid, with m&1. when the total ressure is 1 atm.
(. @or a s!stem s!stem in which which comonent comonent is transfer transferring ring from from the gas hase hase to the li$uid hase, the e$uilibrium relation is gi-en b! PA,I=0.80 x A, I were pAI is the e$uilibrium artial ressure in atm and
×
is the
,I
e$uilibrium li$uid concentratin in molar fraction. t one oint in the aaratus, the li$uid stream contains .( mole and the gas stream contains 9.0 mole . the total ressure is 1 atm. The indi-idual gas8lm coecient at this oi t is k =&3.0 mole/m 'satm. @ift! @ift! ercent of the o-erall resistance to mass transfer is known to be encountered in the li$uid hase, >-aluate a. The o-erall o-erall masstransfe masstransferr coec coecient, ient, ", b. The The mol molar ar u) u) of of c. The li$uid li$uid interfacial interfacial concentrat concentration ion of of “Regardless of how you feel inside, always try to look like a winner. Even if you are behind, a sustained look of control and condence can give you a mental edge that results in victory.”
