Selasa, 22 April 2014

LAMPIRAN A PERHITUNGAN NERACA MASSA



LAMPIRAN A
PERHITUNGAN NERACA MASSA
KAPASITAS PRARANCANGAN
Kapasitas per tahun                 = 10.000 ton/tahun
1 Tahun Operasi                      = 330 hari
Kapasitas prarancangan          =
                                                = 1262,62 kg/jam
KOMPOSISI BAHAN BAKU DAN PRODUK
Bahan baku / produk
Konsentrasi
BM (kg/mol)
Notasi
Asam Acetat
Ethanol
Ethyl Acetat
Air
99,8%
95%
99,8%
60.02
46,08
88,1
18
A
E
EA
W
ANALISA DERAJAD KEBEBASAN
·         Reaktor                =(FI,XA1) (F2,XE2) (F5,XA5) (F6,XE6) (F3,XA3,XE3,XEA3)
·         DESTILASI 1     = (F3,XA3,XE3,XEA3) (F4,XEA4,XE4) (F5,XA5)
·         DESTILASI 2     = (F4,XEA4,XE4) (F7,XEA7,XE7) (F6,XE6)
·         MIXER                = (F7,XEA7,XE7) (F8) (F12,XEA12,XE12) (F9,XEA9,XE9)
·         DEXANTER       = (F9,XEA9,XE9) (F10,XE10) (F11, XE11,XEA11)
·         DESTILASI 3     = (F11, XE11,XEA11) (F12,XEA12,XE12) (F13,XEA13,XE13)
·         DESTILASI 4     = (F6,XE6) (F10 XE10,XEA10) (F14,XE14, XEA14)(F15,XE15)
Neraca Massa total
F1+F2+F8 = F6+F15+F13

1.      REAKTOR
Perbandingan mol reaktan asam asetat : etanol = 1 : 2
  = 
Konversi = 67 %
Reaksi             CH3COOH  +  C2H5OH           «      CH3COOC2H5    +     H2O
Mula-mula                          
Bereaksi                            
Sisa                -        

Neraca massa
F1 + F2 + F5 + F14        = F3
FA + FB = F3...........................................................................................................(1)
FA = F1 + F5
0,998F1 + 0,99 F5 = FAXAA………………………………………….………..…(2)
FB = F2 + F6
0,95F2+F14XE14=FBXEB3………………………………………..…..…………....(3)
Neraca massa asam asetat
FAA.XAA – Asam asetat yang bereaksi = F3.XA3
FAA.XAA                      = F3.XA3
0,33 FAA.XAA = F3.XA3........................................................................................... (4)
Neraca massa etanol
FB.XEB – Etanol yang bereaksi                        =  F3.XE3
46,08 -  46,08            = F3 . XE3
2 46,08 -  46,08         = F3 . XE3
1,021 FA.XAA  = F3.XE3.......................................................................................... (5)
Neraca massa etil asetat
Etil asetat yang terbentuk       =  F3.XEA3
                = F3.XEA3
0,983 FA.XAA  + 109,58  =  F3.XEA3....................................................................... (6)
2.      DISTILASI  01
Neraca massa
F3 = F4 + F5............................................................................................................ (7)
Neraca massa Asam asetat
F3.XA3  = F5.XA5
F3.XA3  = 0,99 F5................................................................................................... (8)
Neraca massa etanol
F3.XE3 = F4.XE4...................................................................................................... (9)
Neraca massa etil asetat
F3.XEA3  = F4.XEA4
F3.XEA3  = 0,2 F4.................................................................................................. (10)

3.      DISTILASI 02
Neraca massa
F4  =  F7  +  F6...................................................................................................... (11)
Neraca massa etanol
F4.XE4  =  F7.XE7  +  F6.XE6
F4.XE4  =  0,09 F7  +  F6.XE6................................................................................ (12)
Neraca massa etil asetat
F4.XEA4  =  F7.XEA7
0,2 F4  =  0,83 F7................................................................................................. (13)

4.      MIXER
Neraca massa
F7  +  F8  +  F12 =  F9............................................................................................ (14)
Dimana F8 =  F7  +  F12
Neraca massa etanol
F7.XE7  +  F12.XE12  = F9.XE9
0,09 F7  +  F12.XE12  = F9.XE9............................................................................... (15)
Neraca massa etil asetat
F7.XEA7  +  F12.XEA12  = F9.XEA9
0,83 F7  + 0,002  F12  =  F9.XEA9.......................................................................... (16)

5.      DEKANTER
Neraca massa
F9  =  F10  +  F11................................................................................................... (17)
Neraca massa etanol
F9.XE9 =  F10.XE10  +  F11.XE11
F9.XE9 =  F10.XE10  +  0,02 F11............................................................................. (18)
Neraca massa etil asetat
F9.XEA9                =  F10.XEA10  + F11.XEA11
F9.XEA9            =  0,93 F11....................................................................................(19)

6.      DISTILASI 03
Neraca massa
F11                   =  F13  +  F12
F11                    = 1262,62+F12...............................................................................(20)
Neraca massa etanol
F11.XE11       =  F13.XE13  +  F12.XE12
0,02 F11        =  0,001.(1262,62)  +  F12.XE12
0,02  F11       =  1,26262  +  F12.XE12................................................................. ...(21)
Neraca massa etil asetat
F11.XEA11             =  F13.XEA13  +  F12.XEA12
0,93 F11               =  0,998. (1262,62)  +  0,002 F12
0,93 F1                            =  1260,094  +  0,002 F12.....................................................(22)

7.      DESTILASI 4
F6 + F10 = F14 + F15
F6 + F10 = FD .......................................................................................................(23)
FD = F14 + F15 .....................................................................................................(24)
Neraca Massa Ethanol
FD + XED = F14 . XE14 + F15 . XE15……………………………………………... (25)
Neraca Massa ethyl asetat
FD                                            = F14 + F15
FD . XEAD                                 = F14 . XEA14 + F15 . XEA15…………….……...…(26)

PENYELESAIAN :
DESTILASI 3
·          Dari persamaan (20) dan (22)
F11                                     =  1262,62  +  F12
0,93 F11                             =  1262,62  +  0,002 F12                 
0,93 ( 1262,62  +  F18 )     =  1262,62  +  0,002 F12
                       0,928  F12   =  85,86
                        F12                 =  92,52 kg/jam
·          Dari persamaan (20)
F11             =  2525,25  +  F12
F11             =  1262,62+  92,52
F11                 =1355,14 kg/jam
·          Dari persamaan (21)
0,02  F11                =  1,26262 +  F.XE12
0,02 ( 1355,14 )     = 1,26262  +   (92,52 ). XE12
27,1 – 1,122          =  92,52 XE12
XE12                       =  0,279

MIXER
·         Dari persamaan (16)
0,83F7 + 0,002F12                          = F9 . XEA9
F9                                                  = F11 + 8%
Ethyl asetat pada arus 11              =
                                                      = 1260,28 kg/jam
Jumlah etil acetat dalam arus 9     =
                                                      = 1369,86 kg/jam
Kehilangan Ethyl Acetat              = (1369,86 - 1260,28 ) kg/jam
= 109,58 kg/jam
0,83 F7  + 0,002  F12                      =  F9.XEA9 
0,83 F7  +  0,002 ( 92,52 )             =  1369,86
0,837F7                                         = 1369,67 kg/jam
F7                                                  = 1650,204 kg/jam
Penambahan air pada mixer equivalent dengan jumlah etanol + ethyl acetat yang larut dalam air
Etanol pada arus  7  :
0,09 . 1650,204                             = 148,51
etanol pada arus 7                         =148,51 kg/jam
Dari arus 12
0,279 . 9252                                  = 25,81
etanol pada arus 12                       =25,81 kg/jam
Total etanol                                   =148,51  +  25,81 = 174,32 kg/jam
Kebutuhan etanol adalah equivalent dengan etanol + ethyl acetat= 283,9 kg/jam
F8                                                  = 283,9 kg/jam

DEKANTER
·         Dari persamaan (14)
F7 + F8 + F12                               = F9
1650,209 + 283,9 + 92,52             = F9
F9                                                  = 2026,629 kg/jam

·         Penyelesaian pada decanter
Dari persamaan (17)
F9                                                  = F10 + F11
F10                                                = ( 2026,629 - 1355,14 )kg/jam
F10                                                = 671,489 kg/jam
DESTILASI  2
·          Dari persamaan (13)
0,2 F4  =  0,83 F7
0,2 F4  =  0,83 (1650,204)
F4  =  6300,845 kg/jam
·          Dari persamaan (11)
F 4 =  F7  +  F6
F6  =  6848,346 -  1650,204
F6  =  5198,142
·         Dari persamaan (16)
0,83F7 + 0,002 . 92,52                  = 2026,629 . XEA9
XEA9                                              = 0,675
·         Dari persamaan (15)
0,09F7 + F12 . XE12                    = F9 . XE9
0,009 . 1650,204 + 92,52 . 0,279  = 2026,629 . XE9
XE9                                              = 0,086
·         Dari persamaan (18)
F9 . XE9                                       = F10 . XE10 + 0,02F11
2026,629 . 0,086                           = 671,489 . XE10 + 0,02 . 1355,14
XE10                                               = 0,219

DESTILASI 4
·         Menentukan kondisi umpan masuk pada kolom disilasi 4
F6 + F10                                       = FD
( 5198,142 + 671,489 ) kg/jam      = FD
FD                                                 = 5869,631 kg/jam
·         Dari persamaan (4) dan (8)
0,33 . FA. XA                               = 0,99F5
F5                                                  = ………………………(A)
·         Dari persamaan (2) dan (A)
0,998 F1 + 0,99F5                                    = FA . XA
0,998F1                                         = FA .XA - 
0,998F1                                         = 0,6 FA . XAA…………..……………..(B)
·         Dari persamaan (6) dan (10)
0,983FA . XA + 109,58                  = F3 . XA3
F3 . XA3                                       = 0,2 . F4…………………………….…..(C)
0,98 FA . XA + 109,58                 = 6848,346 . 0,2
FA . XA                                        = 1281,88 kg/jam………………………..(D)
·         Dari persamaan (B) dan (D)  dieliminasi maka diperoleh
0,998F1                                         = 0,6 . 1281,88
F1                                                   = 860,58 kg/jam
·         Dari persamaan (A)
F5                                                   =
F5                                                   = 427,293 kg/jam
·         Dari persamaan (7)
F3                                                   = F4 + F5
F3                                                   = 6848,346 + 427,293
F3                                                   = 7275,639 kg/jam
·         Dari persamaan (2)
F1 + F5                                           = FA
860,58 + 427,293                          = FA
FA                                                 = 1287,87 kg/jam
·         Dari persamaan
FA + FB = F3
FB = 7275,639 – 1287,87
FB = 5987,769 kg / jam
·         Dari persamaan (D)
FA . XA                                                    = 1281,88 kg/jam
1274,659 . XA                                          = 1281,88
XA                                                              = 0,995
·         Dari persamaan (4)
0,33 . FA. XA                                           = F3 . X3
0,33 . 1281,88                                           = 7275,639 . XA3
XA3                                                            = 0,058
·         Dari persamaan (5)
1,02 FA . XA                                               = F3 . XE3
1,02 . 1287,87 . 0,995                               = 7275,639 . XE3
XE3                                                            = 0,18
·         Dari persamaan (6)
0,983 FA . XA + 109,58                             = F3 . XEA3
1369,66                                                     = 7275,639 . XEA3
XEA3                                                          = 0,188
·         Dari persamaan (9)
F3 . XE3                                                       = F4 . XE4
7275,639 . 0,18                                         = 6848,346 . XE4
XE4                                                            = 0,191
·         Dari persamaan (12)
F4 . XE4                                                      = F6 . XE6 + F7 . XE7
6848,346 . 0,191                                       = 5198,142 . XE6 + 1650,204 . 0,09
XE6                                                            = 0,223
·         Dari persamaan (24) dan(25)
F6 . XE6 + F10 XE10                                = F= . XED
5198,142 . 0,223 + 671,489 . 0,219          = 5869,631 . XED
XED                                                            = 0,311
Diasumsikan XE14                                   = 0,94
·         Komposisi etyl asetat pada FD.
FD = 5869,631 dan jumlah etyl asetat dalam campuran adalah 109,58 sehingga XEAD =
·         Komposisi etanol pada FD
FD                                                              = F14 + F15
FD . XD                                                      = F14 . X14 + F15 . X15
5869,631 . 0,311                                       = 0,94F14 + (FD – F14) 0,05
1825,455                                                   = 0,94F14 + 293,481 - 0,05F14
F14 etanol                                                  = 1721,319 kg/jam
f14 etil acetat                                              =109,52 kg/jam
F14                                                             =1831,151 kg/jam
F15                                                             = FD – F14
                                                                  = ( 5869,631 –1831,151)kg/jam
F15                                                             = 4038,48kg/jam
XEA14                                                         =
XE15                                                           = 0,05
F2                                                              = FB – F14
                                                                  = 5987,769 – 1831,151
F2                                                              = 4156,618 kg/jam
F2 + F14                                                   = FB
F2 . XE2 + F14 . XE14                                   = FB . XB
4156,618. 0,95 +   1831,151 . 0,94           = 5987,769 . XB
 XB                                                                        = 0,946

Perhitungan neraca massa di tiap alat
1.      Neraca massa di reactor
F1 + F2 +F5 +F14                                                =          F3
860,58 + 4156,618+ 427,293 + 1831,151            =          7275,639
2.      Neraca Massa di kolom destilasi 1
F3                                                              =          F4 + F5
7275,639                                                   =          6848,346 + 427,293
3.      Neraca Massa di kolom destilasi 2
F4                                                              =          F6 + F7
6848,346                                                   =          5198,142 + 1650,204
4.      Neraca Massa di mixer
F7 + F8 + F12                                           =          F9
1650,204 + 283,9 + 92,52                         =          2026,629
5.      Neraca Massa di Decanter
F9                                                              =          F10 + F11
2026,629                                                   =          671,489 + 1355,14
6.      Neraca Massa di kolom destilasi 3
F11                                                            =          F12 + F13
1355,14                                                     =          92,52 + 1262,62
7.      Neraca Massa di kolom destilasi 4
F10 + F6                                                   =          F14 + F15
671,489 + 5198,142                                  =          1831.151 + 4038,48