Ch.E. 473 - Assignment No. Four Computer Applications in Chemical Engineering Reading: Chapter 5. Class Discussion: Mass Balances with Reccle !treams Concepts Re"iew o# !ample $ro%lems !olutions o# Mass Balances with Reccle !treams $ro%lems &sing E'cel Assignment Four (NOTE: PART 2 ONLY) DE DATE: Octo!er 22" 2#$% &:## a'm' ot Co*+ (internet) $#:## a'm' ,ard Co*+ F-NAL E.A/: Octo!er E.A/: Octo!er 20" 2#$% 1:## a'm' Part Part -: -: (i"i)e into teams. *or+ through a sprea)sheet ,a%les 5. an) 5./0 an) Figs. 5.10 5.20 an) 5.0 with each person o# a team ta+ing a unit0 showing where the parameters are #or that unit an) chec+ing the results. Are the correct *or+ through the whole process Part -- : Reer to +our Tag Team or +our assigned *ro!lem Pro!lem %'$ and %'3: 4" TNF" D2 , mm Hg, TS, Ɵ, M&N, Pro!lem %'2 and %'0: TSc, Chingu, Co 2 , Delfab, Crasher, XX Prepare the flow sheet for the process in Assignment No. 4. Your report should include a process flow sheet and a table of stream flow rates. rates. In addition, list list the operating operating parameters for for the process equipment. equipment. Also provide provide an overall balance: balance: what fraction of the fed to our process ends up in the product stream! 5.. he process #or ma+ing %enene is )escri%e) %elow an) illustrate) in Figure 5./0 an) ou are to ma+e mass %alances o# it using E'cel. ,6)rocar%on $rocessing0 275 540 p. 5 8tani et al.0 291. he process con"erts toluene to %enene an) 'lenes % )isproportionation ,also calle) transal+lation. he 'lenes also )isassociate to #orm toluene an) trimethl%enene. hese reactions
#orm %enene an) methane. he molar consumption o# h)rogen is a%out ; percent o# that o# toluene.
he reactions an) their con"ersion per pass are: 2 C7H8 Toluene
↔
C6H6 + Benzene
C8H10 (5.11) Xylene; 58% converson!"#ss
2 C8H10 Xylene
↔
C7H8 + C$H12 (5.12) Toluene Tre&'yl Benzene; 1% converson!"#ss
C7H8 Toluene
+
H2 ↔ Hy*roen
C6H6 Benzene
+ CH (5.1) ,e&'#ne; 0.1% converson!"#ss
C8H10 Toluene
+
H2 ↔ Hy*roen
C6H6 Benzene
+
2 CH (5.1) ,e&'#ne; 28% converson!"#ss
he output #rom the reactor contains all the components0 an) the h)rogen an) toluene are reccle)0 the methane is remo"e) #rom the process0 an) the %enene an) 'lenes are remo"e) #rom the process. he "apor pressures o# the components at /; C are: %enene0 75 mm6g toluene0 // mm6g 'lenes0 4.1 < 9.9 mm6g trimethl%enene0 . mm6g. A separation sstem is use) that remo"es the h)rogen an) methane #irst0 then separates the %enene0 then the toluene0 an) then the tri- methl%enene. he h)rogen an) methane shoul) %e somewhat separate) ,to reco"er the h)rogen0 which is reccle) an) the toluene is reccle). =n the separators0 use splits o# 22.2 percent o# the light component out o# the top an) onl ;. percent o# the ne't hea"ier component. &se splits o# ;; percent #or components lighter than the light +e an) ; percent #or components hea"ier than the hea" +e. &se >oal !ee+ or !ol"er to a)?ust the h)rogen ma+eup #ee) to insure the proper amount o# h)rogen enters the reactor ,necessar #or the catalst. o
5./. he process #or ma+ing %enene is )escri%e) %elow an) illustrate) in Figure 5./0 an) ou are to ma+e mass %alances o# it using E'cel. ,6)rocar%on $rocessing0 275 540 p. 5 8tani et al.0 291.
he process con"erts toluene to %enene an) 'lenes % )isproportionation ,also calle) transal+lation. he 'lenes also )isassociate to #orm toluene an) trimethl%enene. hese reactions occur with a catalst in the presence o# h)rogen0 with a tpical ratio o# 7: h)rogen to toluene #ee) to the reactor. he h)rogen also reacts with toluene to #orm %enene an) methane or with 'lenes to #orm %enene an) methane. he molar consumption o# h)rogen is a%out ; percent o# that o# toluene.
he reactions an) their con"ersion per pass are: 2 C7H8 Toluene
↔
C6H6 + Benzene
C8H10 (5.11) Xylene; 58% converson!"#ss
2 C8H10 Xylene
↔
C7H8 + C$H12 (5.12) Toluene Tre&'yl Benzene; 1% converson!"#ss
C7H8 Toluene
+
H2 ↔ Hy*roen
C6H6 Benzene
+ CH (5.1) ,e&'#ne; 0.1% converson!"#ss
C8H10 Toluene
+
H2 ↔ Hy*roen
C6H6 Benzene
+
2 CH (5.1) ,e&'#ne; 28% converson!"#ss
he output #rom the reactor contains all the components0 an) the h)rogen an) toluene are reccle)0 the methane is remo"e) #rom the process0 an) the %enene an) 'lenes are remo"e) #rom the
A separation sstem is use) that remo"es the h)rogen an) methane #irst0 then separates the %enene0 then the toluene0 an) then the trimethl%enene. he h)rogen an) methane shoul) %e somewhat separate) ,to reco"er the h)rogen0 which is reccle) an) the tolune is reccle). =n the separators0 use splits o# 22 percent o# the light component out o# the top an) onl percent o# the ne't hea"ier component. &se splits o# ;; percent #or components lighter than the light +e an) ; percent #or components hea"ier than the hea" +e. &se >oal !ee+ or !ol"er to a)?ust the h)rogen ma+eup #ee) to insure the proper amount o# h)rogen enters the reactor ,necessar #or the catalst. 5.3. @inl chlori)e monomer is the raw material #or ma+ing pol"inl chlori)e ,$@C0 which is pro)uce) in large uantities. *hen $@C was in"ente) ,as a highl elastic polmer % a &ni"ersit o# *ashington gra)uate0 *al)o . !emon0 patent no. 02/204350 the "inl chlori)e was ma)e % reacting acetlene with h)rogen chlori)e. A process which uses cheaper raw materials is now use) ,Cow#er an) >orense+0 2270 an) a simpli#ication o# it is gi"en in Figure 5.4. $repare a mass %alance #or this process using E'cel.
Chlorine an) ethlene are #e) to a )irect chlorination reactor where the reaction C2H
+
Cl2
↔
ClC2HCl
(5.17)
ta+es place with essentiall ;; percent con"ersion o# the limiting reagent. he selecti"it to ethlene)ichlori)e is 22 percent with the main %pro)uct ,an) the onl one consi)ere) here %eing 00/trichloroethane. Ethlene an) o'gen are mi'e) with a h)rogen
ta+es place with a con"ersion o# 29 percent #or ethlene an) ethlene)ichlori)e selec- ti"ities o# 25 percent. 6ere ou can assume the %pro)uct is all 00/-trichloroethane. he output #rom the )irect chlorination reactor is sent to a )istillation tower where the hea" components are )istille) o##. he light components are sent to a #urnace where a prolsis reaction ta+es place: 2 C2HCl2
/
2C2HCl
+ 2HCl
(5.1$)
he #ee) to the #urnace must %e "er pure ,22.5 percent ethlene)ichlori)e toachie"e goo) crac+ing. he output is uenche). he liui) is the "inl chlori)e pro)uct an) the "apor is h)rogen chlori)e0 which is reccle) to the o'chlorination reactor. he output #rom the o'chlorination reactor is coole) to remo"e the liui) ,mostl water. A "ent is use) to remo"e light gases. he remain)er goes to a )istilla- tion column where ethlene)ichlori)e is the hea" component ,an) is sent to the #urnace an) the light components are reccle) to the o'chlorination reactor. he #ee) to the o'chlorination reactor uses a slight e'cess o# o'gen an) ethlene to ensure that all the h)rogen chlori)e reacts. he #ee) to the )irect chlorination reactor is stoichiometric. 5.4. @inl chlori)e monomer is the raw material #or ma+ing pol"inl chlori)e ,$@C0 which is pro)uce) in large uantities. *hen $@C was in"ente) ,as a highl elastic polmer % a &ni"ersit o# *ashington gra)uate0 *al)o . !emon0 patent no. 02/204350 the "inl chlori)e was ma)e % reacting acetlene with h)rogen chlori)e. A process which uses cheaper raw materials is now use) ,Cow#er an) >orense+0 2270 an) a simpli#ication o# it is gi"en in Figure 5.4. $repare a mass %alance #or this process using E'cel.
ight gases Air
8'chlor. reactor
!plitter
Ethlene
6Cl
!plitter @inl chlori)e
water
(irect chl. reactor
6Cl
!plitter
E(C
Furnace
!plitter
!plitter
Chlorine an) ethlene are #e) to a )irect chlorination reactor where the reaction C2H
+
Cl2
↔
ClC2HCl
(5.17)
ta+es place with essentiall ;; percent con"ersion o# the limiting reagent. he selecti"it to ethlene)ichlori)e is 22 percent with the main %pro)uct ,an) the onl one consi)ere) here %eing 00/-trichloroethane. Ethlene an) o'gen are mi'e) with a h)rogen chlori)e reccle stream an) sent to an o'chlorination reactor0 where the reaction. C2H +
2HCl
+
- 2
↔
ClC2HCl
+ H2
(5.18)
ta+es place with a con"ersion o# 29 percent #or ethlene an) ethlene)ichlori)e selecti"ities o# 25 percent. 6ere ou can assume the %pro)uct is all 00/trichloroethane. he output #rom the )irect chlorination reactor is sent to a )istillation tower where the hea" components are )istille) o##. he light components are sent to a #urnace where a prolsis reaction ta+es place: 2 C2HCl2
/
2C2HCl
+ 2HCl
(5.1$)
he #ee) to the #urnace must %e "er pure ,22.5 percent ethlene)ichlori)e to achie"e goo) crac+ing. he output is uenche). he liui) is the "inl chlori)e pro)uct an) the "apor is h)rogen chlori)e0 which is reccle) to the o'chlorination reactor. he output #rom the o'chlorination reactor is coole) to remo"e the liui) ,mostl water. A "ent is use) to remo"e light gases. he remain)er goes to a )istillation column where ethlene)ichlori)e is the hea" component ,an) is sent to the #urnace an) the light components are reccle) to the o'chlorination reactor. he #ee) to the o'chlorination reactor uses a slight e'cess o# o'gen an) ethlene to ensure that all the h)rogen chlori)e reacts. he #ee) to the )irect chlorination reactor is stoichiometric.
