lecture_6
DESCRIPTION
reaction engineeringTRANSCRIPT
REACTION ENGINEERINGCHAPTER 6 NON-ISOTHERMAL REACTOR DESIGNNOOR ROSYIDAH [email protected]: Please make aoi!tme!t "rst #e$ore co!sultatio!s a!d come $ully rearedCHAPTER 6NON-ISOTHERMAL REACTOR DESIGN6.1 The energy balance6.2 Algr!"h#$ %r nn-!$"her#al reac"!n &e$!gn6.' E()!l!br!)# cn*er$!n6.+ M)l"!,le $"ea&y-$"a"e6.1 THE ENERG- .ALANCE/H- /E NEED TO LEARN ENERG- .ALANCE IN REACTION ENGINEERING01. A" "!#e$ 1e nee& " calc)la"e "he *l)#e nece$$ary " ach!e*e a cn*er$!n2 3 !n a reac"r 4%r e5a#,le P6R7 g!*en a %!r$" r&er2 e5"her#!c l!()!& reac"!n carr!e& )" a&!aba"!cally 4n hea" l$$ r ga!ne& !n "he $y$"e#7. 2. 6r an e5"her#!c reac"!n2 "he "e#,era")re ,r%!le *$. *l)#e !$Reac"!n Te#,era")re !n%l)ence&"he Reac"r 8l)#e6.1 THE ENERG- .ALANCE/H- /E NEED TO LEARN ENERG- .ALANCE IN REACTION ENGINEERING0'. 6r "he reac"!n ,re*!)$ly2 1e 9n1 %r# "he c#b!ne& #le balance2 ra"e la12 an& $"!ch!#e"ry y!el&:De$!gn e()a"!n %r P6R:Ra"e La1 46!r$" r&er reac"!n7There !$ change % "e#,era")re &)r!ng "he reac"!n "here%re I" ha$ " "a9en !n" cn$!&era"!nS"!ch!#e"ry %r l!()!& ,ha$e reac"!n g!*e$ 3;A; Ar&36 8A1a1 ACT1T1REe5, 9 r1]1
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7 3 1 4 C C; A A 12'6.1 THE ENERG- .ALANCE/H- /E NEED TO LEARN ENERG- .ALANCE IN REACTION ENGINEERING0'. /e c#b!ne e()a"!n 12 2 an& ' " b"a!n+. In "h!$ e()a"!n2 1e ha*e ' )n9n1n$ 482T an& 37 1h!ch nee& " be $l*e&. There%re 1e nee& an"her rela"!n$h!, rela"!ng 3 an& T r T an& 8.
$y$n1 !! ! !n1 !! + Hea" " "he $y$"e#/r9 &ne by "he $y$"e#T"al $)# r energy !nT"al $)# r energy )"6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-1. In "er#$ % en"hal,y2 "he energy balance bec#e$2. An& %r $"ea&y $"a"e ,era"!n2 "he energy balance n1 bec#e$'. /!"h #an!,)la"!n % "he #lar %l1 ra"e$2 1e b"a!n "he energy balance a$&"E &6 H 6 H / >$y$n1 !! ! !n1 !! + ; 6 H 6 H / >n1 !! ! !n1 !! + ; 3 6 7 T 4 H 7 H H 4 6 / >AO R5n1 !! ! ! AO$ + 12'6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-+. 6r# e()a"!n ' ,re*!)$ly
AO R5n1 !! ! ! AO S + '7 T T 4 C &T C&T C 7 T 4 H &T C 7 T 4 H 7 T 4 H H H! ! P!T!T!P!T!TP R
!T!TP R
! ! ! !R R 11]1
+ 11]1
+ +; 3 6 7 T 4 H 7 T T 4 C 6 / >AO R5n1 !! ! P! ! AO S AO R5n1 !! ! P! ! AO S R P R
AOn1 !! P! ! AO SR5 + [ ] ; 7 T T 4 C 7 T 4 H 3 6 7 T T 4 C 6 / >R P R
AOn1 !! P! ! AO SR5 + 6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-1;.6r# e()a"!n 6 ,re*!)$ly6A. HEAT CAPACIT-2 C,!1. Ty,!cal )n!" %r hea" ca,ac!"y2 C,! % a reac"an" ! !$ re,re$en"e& a$ AB#l.C2. The "er#$ % c)l& be calc)la"e& %r any $,ec!e$ % REACTANT ONL- ba$e& n "he %ll1!ng #e"h&[ ] ; 7 T T 4 C 7 T 4 H 3 6 7 T T 4 C 6 / >R P R
AOn1 !! P! ! AO SR5 + 6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-1;.6r# e()a"!n 6 ,re*!)$ly6A. HEAT CAPACIT-2 C,!2. 6r e5a#,le g!*en a reac"!n % A D .C D D 1!"h A a$ "he ba$!$ % calc)la"!n$2 "here%re: 1!"h~ ~ ~B A iP B P P iC C C + 00ABBFF
POSITI8E SIGN 6OR REACTANTREMEM.ER:ONL- TACE THE REACTANT INTO CONSIDERATION[ ] ; 7 T T 4 C 7 T 4 H 3 6 7 T T 4 C 6 / >R P R
AOn1 !! P! ! AO SR5 + 6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-11.6r# e()a"!n 6 ,re*!)$ly6.. TEMPERATERE S-M.OLS DE6INITION AND DI66ERENCE1. T F Reac"!n Te#,era")re !n 1h!ch "he reac"!n !$ cn&)c"e&2. T!;F En"ranceBInle" Te#,era")re % "he reac"an"'. TRF Re%erence Te#,era")re 4)$)ally 2R P R
AOn1 !! P! ! AO SR5 + 6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-12.6r# e()a"!n 6 ,re*!)$ly6C. Hea" % reac"!n a" re%erence "e#,era")re H R5 4TR71. 6r e5a#,le g!*en a reac"!n % A D bBa .cBa C D &Ba D1!"h A a$ "he ba$!$ % calc)la"!n$2 "here%re:
POSITI8E SIGN 6OR PRODECTNEGATI8E SIGN 6OR R%A&'AN'REMEM.ER: REACTANT AND PRODECT SHOELD .E TACEN INTO CONSIDERATION6.1 THE ENERG- .ALANCE ENERG- .ALANCE IN TERMS O6 ENTHALP-E3AMPLE ON HO/ TO CALCELATE H R5 4TR7Calc)la"e H R5 4TR7 1hen g!*en "he reac"!n a$ %ll1!ng:SOLETION: 6r "he ab*e reac"!n2 "he hea" % reac"!n a" re%erence "e#,era")re !$ a$ %ll1!ng:6r# re%erence2 !" !$ %)n& "ha" "he hea" % %r#a"!n % "he ele#en"$ hy&rgen H H2 4TR7 an& n!"rgen H N2 4TR7 are Her a" 2TO2 6AOT2 6ATa12 #cTa2CSTR reac"rHea" e5changerHea" "ran$%er %l)!& en"er$ "he e5changer a" a #a$$ %l1 ra"e #c 49gB$7 a" a "e#,era")re Ta1 an& lea*e$ a" a "e#,era")re Ta2. 6r e5"her#!c reac"!n$ 4TITa2ITa176r en&"her#!c reac"!n$ 4Ta1ITa2IT7[ ] ; 7 T T 4 C 7 T 4 H 3 6 7 T T 4 C 6 / >R P R
AOn1 !! P! ! AO SR5 + 6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-1+.6r# e()a"!n 6 ,re*!)$ly 6E. HEAT ADDED TO THE REACTOR1. > !$ HEAT a&&e& " "he reac"r 1hen hea"!ng ), a reac"!n !$ re()!re&2. 6r CSTR2 "he > *al)e can be calc)la"e& %r# a $,ec!%!e& e()a"!n)]}C mUAexp( 1 )[ T T {( C m Qccp c1 a.p c. E F O*erall hea" "ran$%er ce%%!c!en" A F Hea" e5change areaC,c F Hea" ca,ac!"y % "he hea" "ran$%er %l)!&6.1 THE ENERG- .ALANCEENERG- .ALANCE IN TERMS O6 ENTHALP-1R P R
AOn1 !! P! ! AO SR5 + 6[ ] 0 ) T T ( C ) T ( H X F ) T T ( C F QR P RoAOn1 iio Pi i AORx + 6.2 ALGORITMS 6OR NON-ISOTHERMAL REACTOR DESIGNCSTR ALGORITHM 6OR NON-ADIA.ATIC S-STEM3 !$ g!*en2 calc)la"e 8 an& T8 !$ g!*en2 Calc)la"e 3 an& T89 *893; +6.2 ALGORITMS 6OR NON-ISOTHERMAL REACTOR DESIGN CSTR ALGORITHM 6OR NON-ADIA.ATIC S-STEM3 !$ g!*en2 calc)la"e T %!r$" )$!ng energy balance e()a"!n1]1
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T1T1REe5, 9 7 T 4 99 CALCELATEO17 3 1 4 9C3 688 CALCELATEAO; AE$!ng "he T ab*e " calc)la"e "he 9[ ] 0 ) T T ( C ) T ( H X F ) T T ( C F QR P RoAOn1 iio Pi i AORx + 6.2 ALGORITMS 6OR NON-ISOTHERMAL REACTOR DESIGN CSTR ALGORITHM 6OR NON-ADIA.ATIC S-STEM8 !$ g!*en2 Calc)la"e 3 an& T89 *893 . 1E>EATION .ALANCE MASS 6ROM T AND 3 CALCELATE;M.M.+/e nee& " ,l" gra,h$ %r cn*er$!n2 3 *er$)$ "e#,era")re2 T an& c#,are "he ,l" " %!n& "he !n"er$ec"!n ,!n".[ ] 0 ) T T ( C ) T ( H X F ) T T ( C F QEQUATO!" #A$A!CE E!ER%& FRO' T A!( X CA$CU$ATER P RoAOn1 iio Pi i AOE#Rx + 6.2 ALGORITMS 6OR NON-ISOTHERMAL REACTOR DESIGNAPPLICATION 6OR CSTR 4NON-ADIA.ATIC S-STEM7E3AMPLE 16ROM >EESTION =.+. PAGE EILI.RIEM CON8ERSIONS 4E3OTHERMIC REACTIONS71. T &e"er#!ne "he #a5!#)# cn*er$!n "ha" can be ach!e*e& !n an e5"her#!c reac"!n carr!e& )" a&!aba"!cally2 1e %!n& "he !n"er$ec"!n % "he e()!l!br!)# cn*er$!n a$ a %)nc"!n % "e#,era")re 1!"h "e#,era")re-cn*er$!n rela"!n$h!,$ %r# "he energy balance. I% "he en"er!ng "e#,era")re !n !ncrea$e& %r# T; " T;12 "he energy balance l!ne 1!ll be $h!%"e& " "he r!gh" an& ,arallel " "he r!g!nal l!ne2 a$ $h1n by "he &a$he& l!ne.N"e: A$ "he !nle" "e#,era")re !ncrea$e$2 "he a&!aba"!c e()!l!br!)# cn*er$!n &ecrea$e$Inle" Te#,era")reE()!l!br!)# cn*er$!n6.+ MELTIPLE STEAD--STATE1. 6r# "he %!g)re bel12 ne 1)l& b$er*e "ha" !% a ,ara#e"er 1ere change& $l!gh"ly2 "here #!gh" be #re "han ne !n"er$ec"!n % "he energy an& #le balance c)r*e$2. /hen #re "han ne !n"er$ec"!n cc)r$2 "here !$ #re "han ne $e" % cn&!"!n$ "ha" $a"!$%y b"h "he energy balance an& #le balance'. Th!$ !$ calle& a$ #)l"!,le $"ea&y $"a"e$ a" 1h!ch "he reac"!n #ay ,era"e Inthermodynamics, the terme(othermic("outside heating") describes a process or reaction that releasesenergyfrom the system, usually in the form ofheat, but also in the form oflight(e.g. a spark, fame, or explosion),electricity(e.g. a battery), orsound(e.g. burning hydrogen). Inthermodynamics, the ordendothermic("ithin!heating") describes a process or reaction in hich the system absorbsenergyfrom the surroundings in the form ofheat. Inthermodynamics, anadia#atic rocessis a con"ersion that occurs ithout input or release ofheatithin a system. #any rapid chemical and physical processes are described in this ay. $uch processes are usually folloed or preceded by e"ents that do in"ol"el heat.