LAMPIRAN A
PERHITUNGAN NERACA MASSA
Kapasitas produksi : 300.000 ton/tahun
Basis perhitungan : 1 jam operasi
Satuan operasi : kg/jam
Waktu operasi per tahun : 330 hari
Kapasitas tiap jam : =(300.000tontahun )×( 1 tahun
330hari )×( 1hari24 jam )×(100 kg
1 ton )¿37.797,51
kgjam
Tabel A.1. Data Berat Molekul masing-masing Komponen
No. Komponen Berat Molekul (kg/kmol)
1 C6H4(COOH)2 166,131
2 4CBA 150,131
3 C6H4(CH3)2 106,165
4 Co(II)(CH3COO)2 153,060
5 CH3COOH 60,052
6 H2O 18,015
7 O2 31,999
8 N2 28,013
Komposisi produk:
- Konversi P-xylene : 98 %
Reaksi utama:
C6H4(CH3)2 + 3O2 C6H4(COOH)2 + 2H2O
(P-xylene) (Oksigen) (TPA) (Air)
Reaksi samping:
C6H4(CH3)2 + 2,5O2 C6H4(COOH)(CHO) + 2H2O
(P-xylene) (Oksigen) (4CBA) (Air)
LA-1
Dasar perhitungan:
Diketahui
- P-xylena = 65 kg/100kg TPA
- Asam asetat = 10 kg/100kg TPA
- Kobalt asetat = 0,1 kg/100kg TPA (Ichikawa, 2009)
Perhitungan umpan continuemelalui alur maju:
Basis perhitungan adalah 37878,7878 kg/jam TPA
- P-xylena
¿65kg
100kg× produksi TPA
¿65kg
100kg×37878.78788 kg / jam
F1 C6H4 (CH3)2= 24621,212 kg/jam
- Asam asetat
¿10kg
100kg× produksi TPA
¿10kg
100kg×37878.78788 kg / jam
F2CH3COOH = 3787,879 kg/jam
Komposisi asam asetat
- CH3COOH = 99%
CH 3COOH=3787.879kgjam
×99 %
¿3750.000kg / jam
- H2O = 1%
CH 3COOH=3787.879kgjam
×1 %
¿37.879kg / jam
- Cobalt asetat
LA-2
¿0.1kg100kg
× produksi TPA
¿0.1kg100kg
×37878.78788 kg / jam
F3 Co(II)(CH3COO)2 = 37,879 kg/jam
LA.1 Mixing Tank (MT-101)
F1
F2
F4
Neraca massa total :
F1 + F2 + F3 + F23(recycle) = F4
Neraca massa komponen:
1. Kobalt asetat
F23 Co(II )(CH3COO)2 + F1Co(II )(CH3COO)2 + F2Co(II )(CH3COO)2 + F3 Co(II )
(CH3COO)2 = F4 Co(II )(CH3COO)2
34,09 kg/jam + 0 + 0 + 3,7.88 kg/jam = F4 Co(II )(CH3COO)2
F4 Co(II )(CH3COO)2 = 37,879 kg/jam
2. P-xylena
F23 C6H4 (CH3 )2 + F1 C6H4 (CH3 )2 + F2 C6H4 (CH3 )2 + F3 C6H4 (CH3 )2 = F4 C6H4
(CH3 )2`
448,69 kg/jam + 24.172,51 kg/jam + 0 + 0 = F4 C6H4 (CH3 )2`
F4 C6H4 (CH3 )2 = 24.621,212 kg/jam
3. Asam asetat
LA-3
F3
F23
F23 CH3COOH + F1 CH3COOH + F2CH3COOH + F3 CH3COOH = F4
CH3COOH
3409,68 kg/jam + 0 + 340,31 kg/jam + 0 = F4 CH3COOH
F4 CH3COOH = 3.750 kg/jam
4. Air
F23 H2O + F1 H2O + F2 H2O + F3 H2O = F4 H2O
154,34 kg/jam + 0 + (F2CH3COOH x 1%) + 0 = F4 H2O
154,34 kg/jam + 0 + (340,31 kg/jam x 1%) + 0 = F4 H2O
154,34 kg/jam + 0 + 3,403 kg/jam + 0 = F4 H2O
F4 H2O = 157,74 kg/jam
Tabel A.2 Neraca Massa di Mix Tank
Komponen
Aliran
masuk 23
Aliran
masuk 1
Aliran
masuk 2
Aliran
masuk 3
Aliran
keluar4
kg/jam kg/jam kg/jam kg/jam kg/jam
P-xylena 448,69 24.172,51 24.621,2
Asam Asetat 3409,68 340,317 3.750
air 154,34 3,403 157,74
cobalt asetat 34,09 3,788 37,87
Total 4046,81 24.172,51 343,72 3,788 28.564,62
28.564,62 28.564,62
LA.2 Reaktor (R-201)
F6
F4 F7
LA-4
F5
Neraca massa total :
F4+ F5 = F6 + F7+ r1 + r2
Data dari neraca massa di tangki pencampuran:
- F4 C6H4 (CH3 )2 = 24621.2 kg/jam
N4 C6H4 (CH3 )2 = 24621.2 kg/jam / BM
= 24621.2 kg/jam / 106.165 kg/kmol
= 232.276 kmol/jam
- F4Co(II )(CH3COO)2 = 37.8788 kg/jam
- N4Co(II )(CH3COO)2 = 37.8788 kg/jam / BM
= 37.8788 kg/jam / 153.060 kg/kmol
= 0.24757 kmol/jam
- F4 CH3COOH = 3750 kg/jam
N4 CH3COOH = 3750 kg/jam / BM
= 3750 kg/jam / 60.02 kg/kmol
= 62.5 kmol/jam
- F4 H2O = 157,74 kg/jam
N4 H2O = 157,74 kg/jam / BM
= 157,74 kg/jam / 18 kg/kmol
= 8,641 kmol/jam
Perhitungan kebutuhan O2:
1 kmol P-xylena = 3 kmol oksigen
= 3 x 232,276 kmol/jam
= 696,828 kmol/jam
= 696,828 kmol/jam x BM
= 696,828 kmol/jam x 32 kg/kmol
= 22.298,496 kg/jam
LA-5
Oksigen ekses = 40 % dari persamaan stokiometri. (Zhou,2011)
N5O2 = (100% + 40% ) × N5O2
= (100% + 40% ) × 696,828 kmol/jam
N5O2 = 975,559 kmol/jam
F5O2 = 975,559 kmol/jam x BM
= 975,559 kmol/jam x 32 kg/kmol
= 31.217,894 kg/jam
Kompoosisi udara:
Nitrogen = 79%
Oksigen = 21%
N5N2 = 79/21 x 975,55 kmol/jam
= 3.669,926 kmol/jam
F5N2 = 3.669,926 kmol/jam x BM
= 3.669,926 kmol/jam x 28 kg/kmol
= 102.757,933 kg/jam
Reaksi 1 (utama):
C6H4(CH3)2 + 3O2 C6H4(COOH)2 + 2H2O
P-xylene Oksigen TPA Air
Reaksi 2 (samping):
C6H4(CH3)2 + 2,5O2 C6H4(COOH)(CHO) + 2H2O
P-xylene Oksigen 4CBA Air
Neraca massa komponen:
1. P-xylene
Konversi P-xylena adalah 98%
- P-xylene yang bereaksi = N4 C6H4 (CH3 )2 x X
= 232,276 kmol/jam x 0,98
= 227,63 kmol/jam
LA-6
- N7 C6H4 (CH3 )2 = N4 C6H4 (CH3 )2 – P-xylene yang bereaksi
N7 C6H4 (CH3 )2 =( 232,276 - 227,63) kmol/jam
= 4,646 kmol/jam
- F7 C6H4 (CH3 )2 = 4.646 kmol/jam x BM
= 4.646 kmol/jam x 106.165 kg/kmol
= 492,424 kg/jam
2. Asam Terepthalat
Selektivitas asam terephtalat 95%
- N7 C6H4(COOH)2 = N4 C6H4(COOH)2 + r1
= 0 + (227,63 kmol/jam x 0,95)
N7 C6H4(COOH)2 = 216,248 kmol/jam
- F7 C6H4(COOH)2 = 216,248 kmol/jam x BM
=216,248 kmol/jam x 166,131 kg/kmol
= 35.897,168 kg/jam
3. 4CBA
Selektivitas 4 CBA 5%
- N7 CHOC6H4COOH = N4 CHOC6H4COOH + r2
N7 CHOC6H4COOH = 0 + (227,63 kmol/jam x 0.05)
= 11,382 kmol/jam
- F7 CHOC6H4COOH = 11,382 kmol/jam x BM
= 11,382 kmol/jam x 150,131 kg/kmol
= 1707,3 kg/jam
4. Oksigen
- N 6O2 = N5O2 - 3r1 – 2,5r2
N 6O2 = 975,559 kmol/jam - 3(227.63 kmol/jam x 0.95) - 2.5(227.63 kmol/jam
x 0.05)
N 6O2 = 298,35 kmol/jam
LA-7
- F6O2 = 298,35 kmol/jam x BM
= 298,35 kmol/jam x 32 kg/kmol
= 9.547,45 kg/jam
5. Air
- N7 H2O = N4 H2O + r1 + r2
N7 H2O = 8,641 kmol/jam + 2(227.63 kmol/jam x 0.95) + 2(227.63 kmol/jam
x 0.05)
N7 H2O = 463,901 kmol/jam
- F7 H2O = 463,901 kmol/jam x BM
= 463,901 kmol/jam x 18 kg/kmol
= 8350,216 kg/jam
6. Kobalt asetat
- F7Co(II )(CH3COO)2 = F4Co(II )(CH3COO)2
= 37,879 kg/jam
7. Asam asetat
- F7 CH3COOH = F4 CH3COOH
= 3.750,0 kg/jam
8. Nitrogen
- F6N2 = F5N2
= 102.757,933 kg/jam
Tabel A.3 Neraca Massa di Reaktor
komponen Aliran masuk 4 Aliran masuk 5 Aliran keluar 6 Aliran keluar 7kg/jam kg/jam kg/jam kg/jam
P-xylena 24.621,2 492,424Asam asetat 3.750 3.750
air 157,74 8350,216cobalt 37,87 37,8788
O2 31.217,839 9.547,45
LA-8
N2 102.758,71 102.758,71 4CBA 1.707,226PTA 35.897,26
Total 28.564,62 133.976,55 112.306,175 50.235,007162.541,182 162.541,182
LA.3 Surge Vessel (SV-201)
F9
F7
F8
Neraca massa total :
F7 = F8 + F9
Perhitungan Flash calculation:
Komponen yg mengalami flash ialah P-xylene, asam asetat, dan air dengan komposisi:
Tabel A.4 Komposisi feed aliran F7
Komponen dalam F7 kmol/jam %
Air 463,90 87,3
Asam asetat 62,50 11,7
P-xylene 4,646 0,87
Jumlah 531,04 100
Tekanan dari 15atm menjadi 1 atm
Dengan menggunakan persamaan antoine didapat tekanan jenuh masing-masing
komponen dalam 102°C:
LA-9
Antoine A B CP-xilena 16.0963 3346.65 -57.84A asetat 16.808 3,405.570 -56.340air 18.304 3,816.440 -46.130
lnP=A−( BT+C )
P1 airsat = 815,812 mmhg
P2 asam asetatsat = 457,54 mmhg
P3 P=xylenesat = 257,07 mmhg
Pbubl = (x1 . P1sat + x2 . P2
sat + x3 . P3sat)
= 0,873 x 815,81 + 0,117 x 457,54 + 0,00874 x 257,07)
= 768,75 mmhg
PDew=1
x1
P1sat+
x2
P2sat+
x3
P3sat
PDew = 734,19 mmhg
Karena tekanan operasi 760 mmhg berada diantara Pbubl = 768,75 mmhg dan PDew =
734,19 maka dapat dilakukan perhitungan flash calculation.
K1 air = P1sat/P
= ( 815,81/ 760) mmhg
= 1,07
K2 asam asetat = P2sat/P
= ( 457,54/ 760) mmhg
= 0,60
K3 P-xylene = P3sat/P
= ( 257,07/ 760) mmhg
= 0,33
LA-10
(x1 . k1)1+V (k1−1)
+(x2 . k2)
1+V (k2−1)+
(x3 . k3)1+V (k 3−1)
=1
(0,873 x1,07)1+V (1,07−1)
+(0,117 x 0,60)1+V (0,60−1)
+(0,0087 x0,33)1+V (0,33−1)
=1 (Van ness, 2005)
Dengan cara iterasi didapat nilai vapor (V) = 0,2717
V = 0,2717 x F
= 0,2717 x 531,04kmol
= 144,28 kmol
L = F – V
= (531,04 – 144,28) kmol
= 386,76 kmol
Menentukan komposisi uap:
- Air
y1=x1k 1
1+V (k 1−1)
y1=(0,873x 1,07)
1+0,2717(1,07−1)
y1 = 0,919
= 0,919 x 144,2 kmol/jam
= 132,65 kmol/jam
=132,65 kmol/jam x BM
= 132,65 kmol/jam x 18
= 2.387,7 kg/jam
- Asam asetat
LA-11
y2=x2k 2
1+V (k 2−1)
y2=(0,117 x 0,60)
1+0,2717(0,60−1)
y2 = 0,079
= 0.079 x 144,2 kmol/jam
= 11,46 kmol/jam
= 11,46 kmol/jam x BM
= 11,46 kmol/jam x 60
= 687,75 kg/jam
- P-xylene
y3=x3 k3
1+V (k3−1)
y3=(0,0087 x0,33)
1+0,2717 (0,33−1)
y1 = 0,0036
= 0.0036 x 144,2 kmol/jam
= 0,52 kmol/jam
= 0,52 kmol/jam x BM
= 0,52 kmol/jam x 106
= 55,17 kg/jam
Neraca massa komponen:
1. Asam Terephthalat
F7 C6H4(COOH)2 = F8 C6H4(COOH)2 + F9C6H4(COOH)2
35.897,26kg/jam = F8 C6H4(COOH)2 + 0
F8 C6H4(COOH)2 = 35.897,26 kg/jam
2. 4CBA
F7 CHOC6H4COOH = F8 CHOC6H4COOH + F9 CHOC6H4COOH
1.707,22 kg/jam = F8 CHOC6H4COOH + 0
LA-12
F8 CHOC6H4COOH = 1.707,22 kg/jam
3. P-xylena
Dari perhitungan flash calculation diatas didapat:
- N9 C6H4 (CH3 )2 = 55,17 kg/jam
- N8 C6H4 (CH3 )2 = N7 C6H4 (CH3 )2 - N9 C6H4 (CH3 )
= (492,42 – 55,17) kg/jam
= 437,24 kg/jam
4. Kobalt Asetat
F7 Co(II )(CH3COO)2 = F8 Co(II )(CH3COO)2 + F9 Co(II )(CH3COO)2
37,878 kg/jam = F8 Co(II )(CH3COO)2 + 0
F8 Co(II )(CH3COO)2 = 37,878 kg/jam
5. Asam Asetat
Dari perhitungan flash calculation diatas didapat:
- N9 CH3COOH = 687,75 kg.jam
- N8 CH3COOH = N7 CH3COOH – N9 CH3COOH
= (3.750 - 687,75) kg/jam
= 3.062,24 kg/jam
6. Air
Dari perhitungan flash calculation diatas didapat:
- N9 H2O = 2.387,72 kg/jam
- N8 H2O = N7H2O - N9 H2O
= (8.350,21 - 2.387,72) kg/jam
= 5.962,49 kg/jam
Tabel A.5 Neraca Massa Di Surge Vessel
LA-13
komponenAliran masuk 7 Aliran keluar 8 Aliran keluar 9
kg/jam kg/jam kg/jam
P-xylena 492,4242 437,24 55,17
Asam asetat 3.750 3.062,24 687,75
air 8.350,21 5.962,49 2.387,72
cobalt 37,87 37,87
4CBA 1.707,226 1.707,26
PTA 35.897,26 35.897,26
Total50.235,007 47.104,35 3.130,65
50.235,007 50.235,007
LA.4 Centrifugasi (S-301)
F8 F10
F11
Neraca massa total :
F8 = F10 + F11
Data: Efisiensi Centrifuges 90% liquid dari F8 menuju F10 (Coulson,1985)
Neraca massa komponen:
1. Asam terephthalat
F8 C6H4(COOH)2 = F11 C6H4(COOH)2 + F10C6H4(COOH)2
35.897,26 kg/jam = F11 C6H4(COOH)2 + 0
F11 C6H4(COOH)2 = 35.897,26 kg/jam
2. 4CBA
LA-14
F8 CHOC6H4COOH = F11 CHOC6H4COOH + F10 CHOC6H4COOH
1.707,26 kg/jam = F11 CHOC6H4COOH + 0
F11 CHOC6H4COOH = 1.707,26 kg/jam
3. P-xylena
- F10C6H4 (CH3 )2 = 90% x F8 C6H4 (CH3 )2
= 0,9 x 437,24 kg/jam
= 393,52 kg/jam
- F11 C6H4 (CH3 )2 + F10C6H4 (CH3 )2 = F8 C6H4 (CH3 )2
F11 C6H4 (CH3 )2 + 393,52 kg/jam = 437,24 kg/jam
F11 C6H4 (CH3 )2 = (437,24 - 393,52) kg/jam
= 43,72 kg/jam
4. Kobalt asetat
- F10 Co(II )(CH3COO)2 = 90% x F8 Co(II )(CH3COO)2
= 0,9 x 37,879 kg/jam
= 34,09 kg/jam
- F 11 Co(II )(CH3COO)2 + F10 Co(II )(CH3COO)2 = F8 Co(II )(CH3COO)2
F11 Co(II )(CH3COO)2 + 34,09 kg/jam = 37,879 kg/jam
F11 Co(II )(CH3COO)2 = (37,879 - 34,09) kg/jam
= 3,787 kg/jam
5. Asam asetat
- F10 CH3COOH = 90% x F8 CH3COOH
= 0,9 x 3.062,24 kg/jam
= 2.756,01 kg/jam
- F11 CH3COOH + F10 CH3COOH = F8 CH3COOH
F11 CH3COOH + 2.756,01 kg/jam = 3.062,24 kg/jam
F11 CH3COOH = (3.062,24 – 2.756,01) kg/jam
= 306,22 kg/jam
6. Air
- F10 H2O = 90% x F8 H2O
LA-15
= 0,9 x 5.962,49 kg/jam
= 5.366,24 kg/jam
- F11 H2O + F10 H2O = F8 H2O
F11 H2O + 5290,63 kg/jam = 5.878,48 kg/jam
F11 H2O = (5.962,49 – 5.366,24) kg/jam
= 596,24 kg/jam
Tabel A.6 Neraca Massa di Centrifugasi
komponenAliran masuk 8 Aliran keluar 10 Aliran keluar 11
kg/jam kg/jam kg/jam
P-xylena 437,24 393,52 43,72
Asam asetat 3.062,24 2.756,01 306,22
air 5.962,49 5.366,24 596,24
cobalt 37,87 34,09 3,78
4CBA 1.707,22 1.707,22
PTA 35.897,26 35.897,26
Total47.104,35 8.549,87 38.554,47
47.104,35 47.104,35
LA.5 Rotary Dryer (RD-301)
F11
F13
LA-16
F12
Neraca massa total :
F11= F12 + F13
Data: Efisiensi Rotary Dryer 80% liquid dari F11 menuju F13 (Woods, 2007)
Neraca massa komponen:
1. Asam terephthalat
F11 C6H4(COOH)2 = F12 C6H4(COOH)2 + F13 C6H4(COOH)2
35.897,26 kg/jam = F12 C6H4(COOH)2 + 0
F12 C6H4(COOH)2 = 35.897,26 kg/jam
2. 4CBA
F11 CHOC6H4COOH = F12 CHOC6H4COOH + F13 CHOC6H4COOH
1.707,226 kg/jam = F12 CHOC6H4COOH + 0
F12 CHOC6H4COOH = 1.707,226 kg/jam
3. Kobalt asetat
F11 Co(II )(CH3COO)2 = F12 Co(II )(CH3COO)2 + F13 Co(II )(CH3COO)2
3,788 kg/jam = F12 Co(II )(CH3COO)2 + 0
F12 Co(II )(CH3COO)2 = 3,788 kg/jam
4. P-xylena
F11 C6H4 (CH3 )2 = F12 C6H4 (CH3 )2 + F13 C6H4 (CH3 )2
- F13 C6H4 (CH3 )2 = 80% x F11 C6H4 (CH3 )2 2
= 0,8 x 43,725 kg/jam
= 34,97 kg/jam
- F12 C6H4 (CH3 )2 = F11 C6H4 (CH3 )2 - F13 C6H4 (CH3 )2
= (43,725 - 34,97) kg/jam
= 8,745 kg/jam
LA-17
5. Asam asetat
F11 CH3COOH = F12 CH3COOH + F13 CH3COOH
- F13 CH3COOH = 80% x F11CH3COOH
= 0,8 x 306,22 kg/jam
= 244,97 kg/jam
- F12 CH3COOH = F 11 CH3COOH - F13 CH3COOH
= (306,22 - 244,97) kg/jam
= 61,24 kg/jam
6. Air
F11H2O = F12H2O + F13H2O
- F13H2O = 80% x F11H2O
= 0,8 x 596,24 kg/jam
= 476,99 kg/jam
- F12H2O = F11H2O - F13H2O
= (596,24 - 476,99) kg/jam
= 119,25 kg/jam
Tabel A.7 Neraca Massa di Rotary Dryer
komponenAliran masuk 11 Aliran keluar 12 Aliran keluar 13
kg/jam kg/jam kg/jam
P-xylena 43,72 8,74 34,97
Asam asetat 306,22 61,24 244,97
air 596,24 119,25 476,99
cobalt 3,78 3,78 0
4CBA 1.707,22 1.707,22 0
PTA 35.897,26 35.897,26 0
Total38.554,47 37.797,51 756,95
38.554,47 38554,47
LA-18
LA.6 Mixing Tank (MT-401)
F9
F10 F14
Neraca massa total :
F9 + F10 = F14
Neraca massa komponen:
1. P-xylena
F9 C6H4 (CH3 )2 + F10 C6H4 (CH3 )2 = F14 C6H4 (CH3 )2
F14 C6H4 (CH3 )2 = 55,176 kg/jam + 393,523 kg/jam
= 448,69 kg/jam
2. Kobalt asetat
F9 Co(II )(CH3COO)2 + F10 Co(II )(CH3COO)2 = F14 Co(II )(CH3COO)2
0 + 34,09 kg/jam = F14 Co(II )(CH3COO)2
F14 Co(II )(CH3COO)2 = 34,09 kg/jam
3. Asam asetat
F9 CH3COOH + F10 CH3COOH = F14 CH3COOH
F14 CH3COOH = 687,75 kg/jam + 2.756,01 kg/jam
= 3.443,77 kg/jam
4. Air
F9H2O + F10H2O = F14H2O
F14H2O = 2.387,72 kg/jam + 5.366,24 kg/jam
=7.753,96 kg/jam
LA-19
Tabel A.8 Neraca Massa di Mixing Tank
komponen Aliran masuk 9 Aliran masuk 10 Aliran keluar 14
kg/jam kg/jam kg/jam
P-xylena 55,17 393,52 448,69
Asam asetat 687,75 2.756,01 3.443,77
air 2.387,72 5.366,24 7.753,96
cobalt 34,09 34,09
Total 3.130,65 8.549,87 11.680,53
11.680,53 11.680,53
LA.7 Evaporator (E-401)
F16
F14
F15
Diinginkan 99% air dan asam asetat menguap
Neraca massa total :
F14 = F15+ F16
Neraca massa komponen:
1. P-xylena
F14 C6H4 (CH3 )2 = F15 C6H4 (CH3 )2 + F16 C6H4 (CH3 )2
448,69 kg/jam = F15 C6H4 (CH3 )2 + 0
F15 C6H4 (CH3 )2 = 448,69 kg/jam
2. Kobalt asetat
LA-20
F14 Co(II )(CH3COO)2 = F15 Co(II )(CH3COO)2 + F16 Co(II )(CH3COO)2
34,09 kg/jam = F15 Co(II )(CH3COO)2 + 0
F15 Co(II )(CH3COO)2 = 34,09 kg/jam
3. Asam asetat
Diinginkan 99% asam asetat menguap
F14 CH3COOH = F15 CH3COOH + F16 CH3COOH
- F16 CH3COOH = 99% x F14 CH3COOH
= 0,99 x 3.443,77 kg/jam
= 3.409,33 kg/jam
- F15 CH3COOH = F14CH3COOH - F16 CH3COOH
= (3.443,77 – 3.409,33) kg/jam
= 34,43 kg/jam
4. Air
- F14H2O = F15H2O + F16H2O
F16H2O = 99% x F14H2O
= 0,99 x 7.753,96 kg/jam
= 7.676,42 kg/jam
- F15H2O = F14H2O - F16H2O
= (7.753,96 – 7.676,42) kg/jam
= 77,54 kg/jam
Tabel A.9 Neraca Massa di Evaporator
komponenAliran masuk 14 Aliran keluar 15 Aliran keluar 16
kg/jam kg/jam kg/jam
P-xylena 448,69 448,69
Asam asetat 3.443,77 34,43 3.409,33
air 7.753,96 77,54 7.676,42
cobalt 34,09 34,09
Total 11.680,53 594,76 11.085,76
LA-21
11.680,53 11.680,53
LA.8 Destilasi (MD-401)
F19
F16
F21
Neraca massa total :
F16 = F19 + F21
Diasumsikan
99% air menguap menuju destilat99% asam asetat menuju buttom destilasi
Neraca massa komponen
1. Air
F19H2O = F16H2O×99%
=7.676,427 kg/jam × 0,99
=7.599,66 kg/jam
F21H2O = F16H2O - F19H2O
= 7.676,427 kg/jam - 7.599,66 kg/jam
= 76,76 kg/jam
2. Asam asetat
F21 CH3COOH= F16 CH3COOH × 99%
= 3.409,33 kg/jam × 0,99
= 3.375,24 kg/jam
F19 CH3COOH = F16 CH3COOH - F21 CH3COOH
= 3.409,33 kg/jam - 3.375,24 kg/jam
= 34,09 kg/jam
LA-22
Tabel A.10 Neraca Massa di Destilasi
komponen Aliran masuk 16 Aliran keluar 19 Aliran keluar 21kg/jam kg/jam kg/jam
Asam asetat 3.409,33 34,09 3.375,24air 7.676,427 7.599,66 77,76
Total 11.085,76 7.633,75 3.452,00911.085,76 11.085,76
Data Bilangan Antoine
Komponen A B CAsam asetat 16.808 3,405.570 -56.340air 18.304 3,816.440 -46.130
Dimana : P = mmhg
T = Kelvin
A. Menentukan Bubble point pada umpan
Dengan menggunakan persamaan antoine:
ln P=A−( BT +C )
a. Menggunakan suhu tebakan 100°C didapat tekanan masing-masing:
P satair = 427,70 mmhg
P satasam asetat = 759,94 mmhg
b. Kemudian dicari nilai K1 menggunakan rumus :
k 1=P sat
P
P asumsi awal = 760 mmhg
K1air=759,9760
=1,00
K1asam asetat=427,70
760=0,563
c. Mencari nilai α
Komponen kunci ialah air dikarenakan kemudahan menguapnya.
α asamasetat=k1asam asetat
k1air (komponen kunci)
=0,5631,00
=0,563
LA-23
α air=k1air
k1air(komponen kunci)
=1,001,00
=1,00
d. Mencari nilai α.xi
xi asam asetat = 11,9% kmol
xi air = 88,1% kmol
sehingga didapat:
α.xi asam asetat = 0,563 x 0,119 = 0,067
α.xi air = 1,00 x 0,881 = 0,881
α.xi total = α.xi asam asetat + α.xi air = 0,948
e. Mencari nilai Kc:
Kcbubl=1
∑ α . xi
¿ 10,948
=1,055
f. Menghitung Pbaru (tekanan)
Pbaru = Kc x Pawal
= 1,055 x 760
= 801 mmhg
g. Menghitung Tbaru (temperatur) menggunakan hokum raoult
T baru=( BA−lnP )−C
¿( 3.816,4418,30−ln 801,72 )−(−46,13)
= 374,65 kelvin
= 101,507°C
Dengan menggunakan perhitungan berulang didapat suhu konstan di feed adalah 374,66
kelvin atau 101,5°C.
B. Menentukan Bubble point pada bottom
Dengan menggunakan persamaan antoine:
ln P=A−( BT +C )
LA-24
a. Menggunakan suhu tebakan 117°C didapat tekanan masing-masing:
P satair = 1346,28 mmhg
P satasam asetat = 736,04 mmhg
b. Kemudian dicari nilai K1 menggunakan rumus :
k 1=P sat
P
P asumsi awal = 760 mmhg
K1air=1346,28
760=1,77
K1asam asetat=736,04
760=0,968
c. Mencari nilai α
Komponen kunci ialah air dikarenakan kemudahan menguapnya.
α asamasetat=k1asamasetat
k1air (komponen kunci)
=0,9681,77
=0,547
α air=k1air
k1air(komponen kunci)
=1,771,77
=1,00
d. Mencari nilai α.xi
xi asam asetat = 93% kmol
xi air = 7% kmol
sehingga didapat:
α.xi asam asetat = 0,93 x 0,547 = 0,509
α.xi air = 0,070 x 1,00 = 0,070
α.xi total = α.xi asam asetat + α.xi air = 0,578
e. Mencari nilai Kc:
Kcbubl=1
∑ α . xi
¿ 10,578
=1,729
f. Menghitung Pbaru (tekanan)
Pbaru = Kc x Pawal
= 1,729 x 760
LA-25
= 1314,31 mmhg
g. Menghitung Tbaru (temperatur) menggunakan hokum raoult
T baru=( BA−lnP )−C
T baru=( BA−lnP )−C=( 3.816,44
18,30−ln1314,31 )−(−46,13)
= 389,257 kelvin
= 116,107°C
Dengan menggunakan perhitungan berulang didapat suhu konstan di buttom adalah
389,221 kelvin atau 116,07°C.
C. Menentukan Dew point pada Destilat
Dengan menggunakan persamaan antoine:
ln P=A−( BT +C )
a. Menggunakan suhu tebakan 90°C didapat tekanan masing-masing:
P satair = 522,91 mmhg
P satasam asetat = 299,65 mmhg
b. Kemudian dicari nilai K1 menggunakan rumus :
k 1=P sat
P
P asumsi awal = 760 mmhg
K1air=522,91
760=0,688
K1asam asetat=299,65
760=0,394
c. Mencari nilai α
Komponen kunci ialah air dikarenakan kemudahan menguapnya.
α asamasetat=k1asam asetat
k1air (komponen kunci)
=0,3940,688
=0,573
LA-26
α air=k1air
k1air(komponen kunci)
=0,6880,688
=1,00
d. Mencari nilai α.xi
xi asam asetat = 0,1% kmol
xi air = 99,9% kmol
sehingga didapat:
α.xi asam asetat = 0,001/ 0,573 = 0,002
α.xi air = 0,999/ 1,00 = 0,999
α.xi total = α.xi asam asetat + α.xi air = 1,001
e. Mencari nilai Kc:
Kc =Yi/ α
= 1,001
f. Menghitung Pbaru (tekanan)
Pbaru = Kc x Pawal
= 1,001 x 760
= 760,772 mmhg
g. Menghitung Tbaru (temperatur) menggunakan hukum raoult
T baru=( BA−lnP )−C
T baru=( BA−lnP )−C=( 3.816,44
18,30−ln760,772 )−(−46,13)
= 373,181 kelvin
= 100,031°C
Dengan menggunakan perhitungan berulang didapat suhu konstan di destilat adalah
373,181 kelvin atau 100,031°C.
D. Menghitung reflux
LA-27
Tabel A.11 komposisi umpan masuk
komponen Kmol/jam % kmol
Asam asetat 56,8223 0,1175
Air 426,46 0,8824
Jumlah 483,29 1
Data kesetimbangan asam asetat – air :
Tabel A.12 kesetimbangan asetat -air
Air (mol/mol) (x) Air (mol/mol) (y)
0,85 0,9083
0,8824 y
0,9 0,9423
Dari tabel diatas didapat nilai y pada x :
x = 0,8824
y = 0,9303
kemurnian air yang diinginkan xD : 0,99
Rm=xD− y '
y '−x ' (Mc. Cabe, 1993)
Rm= 0,99−0,93030,9303−0,8824
Rm = 1,2463
R = 1,5 Rm (Geankoplis)
R = 1,5 x 1,2463
= 1,8695
Kondensor
Alur 18 (reflux kondensor)
R : Ld/D = 1,8695
Total : Ld (N18) = R.D
= 1,8695 x 422,77 kmol/jam
LA-28
= 790,38 kmol/jam
Air : N18H2O= xD. N18
= 0.998 x 790,38 kmol/jam
= 789,3177 kmol/jam
F18H2O = 789,3177 x BM
= 789,3177 x 18
=14.207,71 kg/jam
Asam asetat : N18asam asetat = xD. N18
= 0.0013 x 790,38 kmol/jam
= 1,0623 kmol/jam
F18 asam asetat = 1,0623 x BM
= 1,0623 x 60
= 63,738 kg/jam
Alur 17 (umpan kondensor)
Total : Vd (N17) = Ld + D
= (790,38 + 422,77) kmol/jam
= 1.213,152 kmol/jam
Air : N17H2O= xD. N17
= 0.998 x 1.213,152 kmol/jam
= 1.211,52 kmol/jam
F17H2O = 1.211,52 x BM
= 1.211,52 x 18
= 21.807,38 kg/jam
Asam asetat : N17asam asetat = xD. N17
= 0.0013 x 1213,152 kmol/jam
= 1,6305 kmol/jam
F17 asam asetat = 1,6305 x BM
= 1,6305 x 60
LA-29
= 97,83 kg/jam
Neraca massa Total condenser
Tabel A.13 Neraca massa condensor
Komponen Masuk (kg/jam) Keluar (kg/jam)
Aliran 17 Aliran 18 Aliran 19
Asam asetat 97,83 63,738 34,09
air 21.807,38 14.207,71 7.599,66
Total 21.905,21 14271,45 7.633,75
21.905,21 21.905,21
Reboiler
Lb = Ld + F
Alur 20 (umpan reboiler)
Total : Lb (N20) = Ld + F
= 790,38 + 483,290 kmol/jam
=1273,67 kmol/jam
Air : N20H2O= xB. N20
= 0.07 x 1273,67 kmol/jam
= 89,7539 kmol/jam
F20H2O = 89,7539 x BM
= 89,7539 x 18
= 1.615,57 kg/jam
Asam asetat : N20asam asetat = xB. N20
= 0.9295 x 1273,67kmol/jam
= 1.183,9165 kmol/jam
F20 asam asetat = 1.183,9165 x BM
= 1.183,9165 x 60
= 71.034,99 kg/jam
LA-30
Alur 22(reflux reboiler)
Total : Vb (N22) = Lb - B
= (1.273,67 + 60,519) kmol/jam
= 1.213,152 kmol/jam
Air : N22H2O= xB. N22
= 0.07 x 1.213,152 kmol/jam
= 85,4892 kmol/jam
F22H2O = 85,4892 x BM
= 85,4892 x 18
= 1.538,80 kg/jam
Asam asetat : N22asam asetat = xB. N22
= 0.9295 x 1213,152 kmol/jam
= 1.127,662 kmol/jam
F22 asam asetat = 1.127,662 x BM
= 1.127,662 x 60
= 67.659,74 kg/jam
Neraca massa Total reboiler
Tabel A.14 Neraca massa reboiler
Komponen Masuk (kg/jam) Keluar (kg/jam)
Aliran 20 Aliran 21 Aliran 22
Asam asetat 71.034,99 3.375,24 67.659,74
air 1615,57 76,764 1.538,80
Total 72.650,56 3.452,01 69.198,55
72.650,56 72.650,56
LA.9 Mixing Tank (MT-402)
LA-31
F15 F21
F23
Neraca massa total :
F15 + F21= F23
Neraca massa komponen:
1. P-xylena
F15 C6H4 (CH3 )2 + F21 C6H4 (CH3 )2 = F23 C6H4 (CH3 )2
448,69 kg/jam + 0 = F23 C6H4 (CH3 )2
F23 C6H4 (CH3 )2 = 448,69 kg/jam
2. Kobalt asetat
F15 Co(II )(CH3COO)2 + F21 Co(II )(CH3COO)2 = F23 Co(II )(CH3COO)2
34,09 kg/jam + 0 = F23 Co(II )(CH3COO)2
F23 Co(II )(CH3COO)2 = 34,09 kg/jam
3. Asam asetat
F15 CH3COOH + F21 CH3COOH = F23 CH3COOH
34,43 kg/jam + 3.375,24 kg/jam = F23 CH3COOH
F23 CH3COOH = 3409,68 kg/jam
4. Air
F15H2O + F21H2O = F23H2O
77,54 kg/jam + 76,76 kg/jam = F23H2O
F23H2O = 154,30 kg/jam
LA-32
Tabel A.15 Neraca massa mixing tank (MT-402)
komponen Aliran masuk 15 Aliran masuk 21 Aliran keluar 23
kg/jam kg/jam kg/jam
P-xylena 448.699 448.699
Asam asetat 34.438 3375.245 3409.683
air 77,54 76,76 154,34
cobalt 34.091 34.091
Total 594.768 3452.009 4046.77
4046.81 4046.81
LA-33
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