Pra Rancangan Pabrik Dimetil Tereftalat dari Asam Tereftalat dan Metanol dengan Kapasitas 60.000 Ton / Tahun
LAMPIRAN A
PERHITUNGAN NERACA MASSA
Kapasitas produksi Dimetil Tereftalat (DMT) = 60.000 ton/tahun 1 tahun = 330 hari kerja 1 hari = 24 jam kerja Kapasitas tiap jam = 60.000 x x x
= 7575,7576 kg / jam Kemurnian dari Dimetil Tereftalat (DMT) adalah 99,7%, maka : Jumlah Dimetil Tereftalat (DMT) = 99,7% x 7575,7576 kg/jam
= 7553,0303 kg/jam
A.1 Penentuan Komposisi Bahan Baku
Komposisi Asam Tereftalat : 98,5% Asam Tereftalat (AT) : 6483,4888 kg/jam 1,5% Impurities (I) : 98,7333 kg/jam
Total : 6582,2222 kg/jam Komposisi Metanol
99,4% Metanol (M) : 2880,3048 kg/jam : 17,3861 kg/jam
0,6% Air (W) Total : 2897,6909 kg/jam
I AT 83,933% M 0,356% W 0,029% DMT 15,682%
58702,5542 + 6582,2221 + 297,7901 = F
AT M W DMT
AT 98,5% I 1,5%
M (aq) 99,4% W(l) 0,6%
SB - 01
I : = 6582,2221 x 1,5% = 98,7333 kg/ jam
AT : = 6582,2221 x 98,5% = 6483,4888 kg/jam = 297,7901 x 83,933% = 249,9455 kg/jam = = 6483,4888 + 249,9455 = 6733,4340 kg/jam
12
Neraca Massa Komponen :65582,5663 kg/jam = F
12
12
- F
= F
11
10
9
F
Gambar A.1 Aliran Proses pada Sublimator (SB-01) Neraca Massa Total :
Fungsi: Menyublimasi Fresh Asam Terephthalic ( AT ) dan hasil recycle dari Desublimator (DE-01 ) dengan reaktan uap metanol bersuhu tinggi.
A.2 Perhitungan Neraca Massa A.2.1 Sublimator (SB-01)
(9) (12) (10) (11)
- F
= = 98,7333 kg/jam
M : = 58702,5542 x 99,4% = 58350,3389 kg/jam = 297,7901 x 0,356% = 1,0607 kg/jam = = 58350,3389 + 1,0607 = 58351,3996 kg/jam
W : = 58702,5542 x 0,6% = 352,2153 kg/jam = 297,7901 x 0,029% = 0,0851 kg/jam = = 352,2153 + 0,0851 = 352,3004 kg/jam
DMT : = 297,7901 x 15,6892% = 46,6990 kg/ jam
= = 46,6990 kg/jam
Tabel A.1 Neraca Massa pada Sublimator (SB-01) Masuk (kg/jam) Keluar (kg/jam)
Komponen Alur 9 Alur 10 Alur 11 Alur 12
Asam Tereftalat 6483,4888 249,9455 6733,4340 Metanol 58350,3389 1,0607 58351,3996
Air 352,2153 0,0851 352,3004 Dimetil Tereftalat 46,6989 46,6990
Impuritis 98,7333 98,7333 subtotal 58702,5542 6582,2221 297,7901 65582,5663 total 65582,5663 65582,5663
A.2.2 Ash Filter (CN-01)
Fungsi : Memisahkan inert berupa logam-logam yang tidak tersublimasi dari uap metanol AT
AT M
(14) (12)
M
CN - 01
W W DMT
(13)
DMT
I I Gambar A.2 Aliran Proses pada Ash Filter (CN-01)
Neraca Massa Total :
12
13
14 F = F + F
14
65582,5663 = 98,7333 + F
13
65483,8330 kg/jam = F Neraca Massa Komponen : AT : = = 6733,4340 kg/jam I : = = 98,7333 kg/jam M : = = 58351,3996 kg/jam W : = = 352,3004 kg/jam DMT : = = 46,6990 kg/ jam Tabel A.2 Neraca Massa pada Ash Filter (CN-01)
Keluar (kg/jam) Masuk (kg/jam)
Komponen Alur 14
Alur 12 Alur 13 6733,4340 6733,4340
AT 58351,3996 58351,3996
M 352,3004 352,3004
W 46,6990 46,6990
DMT I 98,7333 98,7333
65483,833 subtotal 65582,5663 98,73333 65582,5663 total 65582,5663
A.2.3 Reaktor (R-01)
Fungsi : Mengesterifikasi Asam Terephthalic dengan Metanol pada fase gas menjadi Dimetil Tereftalat.
AT AT
(15) (14) R - 01 M
M W W DMT DMT
Gambar A.3 Aliran Proses pada Reakor (R-01) Reaksi yang terjadi di dalam Reaktor :
- + P- C H ( COOH ) CH OH P-C H ( COOCH ) H O
2 → +2
6
4
2
3
6
4
3
2
2 X = 0,96 AT
= r = 0,96 x
1
= 0,96 x 40,5316 = 38,9103 kmol/jam
Neraca Massa Total :
14
15 F = F
15
65582,5663 kg/jam = F Neraca Massa Komponen : AT : = x
- – ( r
1
= 6733,4340
- – (38,9103 x 166,128) = 269,3374 kg/jam
= 0,0009 M : = x
- – ( 2 x r
1
= 58351,3996
- – ( 2 x 38,9103 x 32,042 ) = 55857,8695 kg/jam =
15 N M 1743,2704
15
= = =0,9266
M
15
1881,4180 N
W : = + ( 2 x r x
1
= 352,3004 + (2 x 38,9103 x 18,016) = 1754,3177 kg/jam =
0,0518 DMT : = + ( r x
1
= 46,6990 + (38,9103 x 194,18) = 7602,3084 kg/jam
=
15 N 39,1508 DMT
= = =0,0208
DMT
15
1881,4180 N
Tabel A.3 Neraca Massa pada Reaktor (R-01) Masuk (kg/jam) Keluar (kg/jam)
Komponen Alur 14 Alur 15
AT 6733,4340 269,3374 M 58351,3996 55857,8695 W 352,3004 1754,3177
DMT 46,6990 7602,3084 total 65483,833 65483,833
(17) (11) (18)
A.2.4 Cyclone (CN-03)
Fungsi : Memisahkan Asam Tereftalat yang tidak bereaksi untuk direcycle kembali ke reaktor.
Gambar A.4 Aliran Proses pada Cyclone (CN-03)
Penentuan Dew Point
Untuk menentukan titik dew point, berlaku Zi Yi = dan
Pio Yi P Xi
=
TRIAL
T, SuhuZA,ZB,ZC,ZD P
APAKAH
XA + XB +XC + XD=1 ?
NOYES
T = T DEW POINT PAo, PBo, PCo, PDo
Alogaritma menentukan suhu dew point
CN - 03AT M W DMT AT M W DMT AT M W DMT
XA, XB, XC, XD
Tekanan Uap Jenuh dapat dihitung dengan menggunakan Persamaan Antoinne sebagai berikut :
= 874 0,9266 82095,5094
= 874 0,0009 0,8313
AT
= 0,9463 =
= = 82095,5094 mmHg
M
= P
M
P
M o M
M = 0,0099
.
= = = 35421,0933 mmHg
= P P
o
= 874 0,0518 35421,0933
= 0,0013 =
=
DMT =
P
DMT
P
AT
AT o
T B A P o = ln
421 , 19 ln
T P o 7524 1 , 156 ,
20 ln =
, untuk DMT
T P o 16880 485 ,
31 ln =
, untuk AT 29 , 34 3626 55 ,
5875 , 18 ln
=
T P o
, untuk Metanol 421 , 19 4770 9 ,
=
P
T P o
, untuk air dengan : o
P = tekanan uap jenuh , mmHg
T = suhu, kelvin Trial T = 259,85
o
C (533 K) ; P = 1,15 atm (874mmHg) =
= = 0,8313 mmHg
AT
= P
AT
DMT o
= 419,6788 mmHg 874 0,0208
AT =
419,6788 = 0,0433
AT
0,9463 + 0,0099 + 0,0013 + 0,0433 = 1,0008
o
Suhu dew point berkisar 260 C , HE-01 digunakan terlebih dahulu untuk mendinginkan produk gas dari reaktor sebelum produk gas didesublimasi. HE-01
o o akan menurunkan suhu gas produk dari 330 C sampai suhu 270 C .
Kesetimbangan
Diasumsikan bahwa produk yang keluar dari desublimator telah mencapai kesetimbangan yaitu kesetimbangan 2 fase dan 4 komponen. Sehingga komposisi dan jumlah komponen di fase gas dan fase padat bisa dihitung dengan alogaritma
L Zi
1
( ) Pio
G
sebagai berikut : dan
mi = Xi = L P mi G
TRIAL L/G
PAo, PBo, PCo, PDo mA, mB, mC, mD
ZA,ZB, ZC,ZD
NO YES Congratulation T,P
AT
AT = 0,0001
AT = m AT AT y
AT = 0,0009 (1+0,0009485) 0,0001+ 0,0009485 y
=0,0001
AT
874 m
= 0,0643
P m
XA + XB +XC + XD =1 ?
dan
YA + YB + YC + YD =1?
APAKAH
= P
AT
C (493,15 K) ; P = 1,15 atm (874mmHg) ; L/G = 0,0009485 = = = 0,0643 mmHg m
o
Trial T = 220
XA, XB, XC, XD YA, YB, YC, YD Alogaritama perhitungan kesetimbangan
AT o o y
=
= m M M
P
M M
m =
M
P
y = 0,9274 M
45656,5666
09266 (1+0,0009485)
m =
M
= 874 M =
49,9503+ 0,0009485 o
43656,5666
P m M =49,9503
M = mmHg o y
=
= m
P m = P
y = 0,0518
17097,0560
0,0518 (1+0,0009485)
m = = 874 =
19,5618+ 0,0009485 =17097,0560
m =19,5618
mmHg o y = m DMT DMT
P = DMT DMT m DMT =
P
y = 0,0207 DMT
134,1255 m = 0,0208 (1+0,0009485)
DMT
= 874 DMT =
0,1535+ 0,0009485 =134,1255
m =0,1535
DMT mmHg Σ = 1,0000 Σ = 1,0000
1,6213 + 1743,2704 + 97,3755 + 39,1508
kmol
1881,4180
jam
- 18
M
11
11 Mr M M
L
M
=
11
0,0001 M :
M
kmol jam
=0,1167
19,3919 166,128
=
18 Mr AT
AT
= 0,0186 1,7828 32,042
11
18
18
=1743,2373
55856,8088 32,042
=
18 Mr M
M
= 55856,8088 kg jam =
M
= 1,0607 kg/jam
= 0,9274 1879,6352 32,042
18
18 Mr M M
= y
18
M
= 19,3919 kg jam =
AT
Neraca Massa Total : N
= 0,0009485 = 0,0009485
18 L
17
= N
11
= L
1881,4180 = 0,0009485 1881,4180 = 1,0009485 1879,6352 kmol jam
11
= 1881,4180 1879,6352 1,7828
= L
18
N
11
= L
17
11
kmol jam
= 0,0001 1879,6352 166,128
= 249,9455 kg/jam
18
18 Mr AT AT
AT
= y
18
AT
11
Neraca Massa Komponen : AT :
AT
= 0,8439 1,7828 166,128
11
11 Mr AT AT
= AT L
11
AT
kmol jam
0,9274 W :
18
11
11 Mr
= 0,0026 1,7828 18,016
DMT
= y
DMT
18 Mr DMT DMT
18
= 0,0208 1879,6352 194,18
DMT
18
= 7555,6095 kg jam =
18 Mr DMT
DMT
=
7555,6095
= 38,9103
kmol jam
0,0207 Tabel A.4 Neraca Massa pada Cyclone (CN-03)
Komponen Masuk (kg/jam) Keluar (kg/jam)
Alur 17 Alur 11 Alur 18 Asam Tereftalat 269,3374 249,9455 19,3919
Metanol 55857,8695 1,0607 55856,8088 Air 1754,3177 0,0851 1754,2328
Dimetil Tereftalat 7602,3084 46,6990 7555,6095 subtotal 65483,8330 297,7901 65186,0428
18
= 46,6989 kg/jam
11
=
= 0,0851 kg/jam
11
= y
18 Mr
18
= 0,0518 1879,6352 18,016
18
= 1754,2326 kg jam =
18 Mr
1754,2326 18,016
11
=97,3708 0,0518
DMT :
DMT
11
= AT L
11 Mr DMT DMT
11
= 0,1349 1,7828 194,18
= L
DMT
(19) (21)
(20) total 65483,8330 65483,8330
A.2.5 Tangki Separator (TS-02)
Fungsi : Untuk memisahkan semua hasil produk DMT dari campuran uap hasil reaktor Gambar A.5 Aliran Proses pada Tangki Separator (TS-02)
Kesetimbangan Trial T = 72
o
C (345,15 K) ; P = 1,1 atm (836mmHg) ; L/G = 0,281
TS - 02
AT M W DMT AT M W DMT M W o y = m AT AT
P AT
AT
= m =
AT
P
y = 0,0000 AT
= 0,0000
0,0001 (1+0,281)
m =
AT
836 AT =
0,0000+ 0,281
= 0,0000 mmHg m AT =0,0000
o y
=
= m M M
P M
M
m =
M
P
y = 0,9645 M
1013,6529
0,9274 (1+0,281)
m =
M
= 836 M =
1,2125+ 0,281 = 1013,6529 m =1,2125
M mmHg o y
=
= m
P m = P
y = 0,0355
269,9709 m = 0,0518 (1+0,281) = 836 =
0,3229+ 0,281
m =0,3229
= 269,9709 mmHg o y = m DMT DMT
P DMT DMT = m =
DMT
P
y = 0,0000 DMT
0,19333
0,0207 (1+0,281)
m =
DMT
= 836 DMT =
0,0002+ 0,281
m DMT =0,0002 = 0,1933 mmHg
Σ = 0,9999 Σ = 1,0000
- 20
= 0,281 = 0,281
21
= 1879,6352 1467,3187 L
21
20 L
= N
21
0,1167 + 1743,2373 + 97,3708 + 38,9103 1879,6352
1879,6352 = 0,281 1879,6352 = 1,281 1467,3187 kmol jam
21
kmol jam
= L
20
N
21
= L
19
Neraca Massa Total : N
kmol jam
412,3165
20 L
Neraca Massa Komponen : AT :
M
= M L
21 Mr M M
21
= 0,7955 412,3165 32,042
M
21
= 10509,3580 kg/jam
20
M
= y
20 Mr M M
20
= 0,9645 1467,3187 32,042
M
20
= 45347,4508 kg jam
21
= 0,0000 kg jam M :
AT
= 19,3919 kg/jam
21
= AT L
21 Mr AT AT
21
= 0,0003 412,3165 166,128
AT
=
AT
20
20
= y
AT
20 Mr AT AT
20
= 0,0000 1467,3187 166,128
AT
21 W :
21
20
21 Mr
= 0,1099 412,3165 18,016
= 0,0000 1467,3187 194,18
DMT
20
= y
DMT
20 Mr DMT DMT
20
DMT
21
20
= 0,000 kg jam Tabel A.5 Neraca Massa pada Tangki Separator (TS-02)
Komponen Masuk (kg/jam) Keluar (kg/jam)
Alur 19 Alur 20 Alur 21 Asam Tereftalat 19,3919 19,3919
Metanol 55856,8088 45347,4508 10509,3580 Air 1754,2328 938,0156 816,2171
Dimetil Tereftalat 7555,6095 7555,6095 subtotal 65186,0428 46285,4664 18900,5765 total 65186,0428 65186,0428
= 7555,6095 kg/jam
DMT
21
20
= 816,2171 kg/jam
21
= y
20 Mr
20
= 0,0355 1467,3187 18,016
= 938,0156 kg jam DMT :
= 0,0943 412,3165 194,18
DMT
21
=
DMT
L
21 Mr DMT DMT
= L
21
A.2.6 Crystalyzer (CR-01)
Fungsi : Mengkristalisasi produk DMT ( Dimethyl Tereftalat ) dari hasil kondensasi CD-01 AT M (26) W DMT AT
AT (22)
M (21) M
CR - 01
W W DMT DMT
Gambar A.6 Aliran Proses pada Cooling Crystalizer (CR-01)
Data Kelarutan
Kelarutan Asam Terephthalic dalam g / 100 g metanol
o
Suhu, C 25 160 Kelarutan 0,1 2,9
(Kirk & Othmer) Kelarutan Dimethyl Terephthalate dalam g / 100 g metanol
o
Suhu, C
25
60 Kelarutan 1,0 5,7 (Kirk & Othmer) Persamaan Clausius-Clapeyron
d ln S H =
2 dT RT
H ln d S = dT
2 RT
1 H ln S = C
R T Dari data kelarutan yang tersedia di plot 1/T (sumbu x) dengan ln S (sumbu y). Maka diperoleh gambar sebagai berikut 1,5
1 y = -3221.2219x + 8.5014 0,5
0,001 0,002 0,003 0,004
S
- 0,5
ln
- 1
Kelarutan AT dalam Metanol
- 1,5 <
- 2,5
1/T
2 1,5 y = -4,939.3770x + 16.5668
S
1
ln
0,5 Kelarutan DMT dalam Metanol
0,0029 0,003 0,0031 0,0032 0,0033 0,0034
1/T
Diperoleh persamaan :
1 AT : ln 3221 , 2219 8 , 5014 S = T
1 DMT : ln S 4939 , 3770 16 , 5668 = T o
T = 72 C (345,15 K)
21 AT :
21 M M
1 S = AT ln 3221 , 2219 8 , 5014
100
345 ,
15
10537,6821
21 AT ln = , 8314
100 S
21 AT
, 8314 = e
S = , 4355
S
21
26 DMT :
21 M M
1 S = DMT ln 4939 , 3770 16 , 5668
100
345 ,
15
10537,6821
21
(a )=9,5447
DMT 100 ln = 2 , 2560
S
21 2 , 2560
(a )=670,5276
DMT =
S e
21
21
21
26
9 , 5447
(s)= (a )
- S =
DMT DMT DMT DMT
21
(s)=7555,6095+27,0528 670,5276
DMT
21
(s)=6912,1346
DMT o
T = 10 C (283,15 K)
21
26 AT :
22 M M
1 ln S = 3221 , 2219 8 , 5014 AT
100
283 ,
15
10537,6821
22 AT =
100 ln S 2 , 8749
22 2 , 8749
AT
34
= e S
22
22
21
26
(s)= (a )
- S = , 0564
AT AT AT AT
22
(s)=19,3919+3,6707 3,9634
AT
22
(s)=19,0992
AT
21
26 DMT
1
22 M M
ln S = 4939 , 3770 16 , 5668 DMT
100
283 ,
15 :
10537,6821
22
(a )=0,4158
DMT 100 ln = , 8776
S
22 DMT (a )=29,2095 , 8776
S = e
22
22
21
21
(s)= (s)+ (a )
DMT DMT DMT DMT =
S , 4158
22
(s)=6912,1346+670,5276 29,2095
DMT
22
(s)=7553,4527
DMT
Tabel A.6 Neraca Massa pada Crystalyzer (CR-01) Masuk (kg/jam) Keluar (kg/jam)
Komponen Alur 21 Alur 26 Alur 22
Asam Tereftalat 19,3919 3,6707 3,9634
(aq)
Asam Tereftalat 19,0992
(s)
Metanol 10509,3580 28,3241 10537,6821 Air 816,2171 8,1922 824,4093
Dimetil Tereftalat 670,5276 29,2095
(aq)
Dimetil Tereftalat 6912,1346 7553,4527
(s)
total 18967,8163 18967,8163
A.2.7 Centrifuge (CF-01)
Fungsi : Memisahkan padatan dari slurry yang berasal dari Cooling ( CR
Crystalizer
- – 01 ) AT
AT M (23)
M (22)
CF - 01
W W DMT DMT AT
(25) M W DMT
Gambar A.7 Aliran Proses pada Centrifuge (CF-01) Fraksi Massa Cairan
Komponen Alur 22 x
i
AT (aq) 3,9624 0,0003 M 10537,6821 0,9247
W 824,4093 0,0723 DMT (aq) 29,2095 0,0027
Σ=11395,2643 Σ=1 Sisa cairan dalam padatan = 10%
22
2
Σ padatan = (s) + (s)
AT DMT
= 19,0992 + 7553,4527 = 7572,5520 kg/jam
90
10 =
Σ padatan Σ cairan
90
10 =
7572,5520 Σ cairan Σ cairan = 841,3947 kg/jam
Neraca Massa Komponen : AT = x
(aq) Σ cairan
= 0,0003 x 841,3947
= 0,2926 kg/jam = = 3,9634
0,2926 = 3,6707 kg/jam AT = = 19,0992 kg/jam
(s)
M : = x Σ cairan
= 0,9247 x 841,3947 = 778,0732
= = 10537,6821
- – 778,0732 = 9759,6089 kg/jam W : = x
Σ cairan = 0,0723 x
841,3947 = 60,8721 = = 824,4093
- – 60,8721 = 763,5372 kg/jam DMT = x
(aq) Σ cairan
= 0,0027 x 841,3947 = 2,1567 kg/ jam
= = 29,2095
- – 2,1567 = 27,0528 kg/jam DMT = = 7553,4527 kg/jam
(s) Tabel A.7 Neraca Massa pada Centrifuge (CF-01) Masuk (kg/jam) Keluar (kg/jam)
Komponen Alur 22 Alur 25 Alur 23
Asam Tereftalat 3,9634 0,2926 3,6707
(aq)
Asam Tereftalat 19,0992 19,0992
(s)
Metanol 10537,6821 778,0732 9759,6089 Air 824,4093 60,8721 763,5372
Dimetil Tereftalat 29,2095 2,1567 27,0528
(aq)
Dimetil Tereftalat 7553,4527 7553,4527
(s)
Subtotal 18967,8163 8413,9466 10553,8697 Total 18967,8163 18967,8163
A.2.8 Tangki Separator (TS-03)
Fungsi : Memisahkan sisa DMT yang terlarut pada larutan filtrat Centrifuge (CF-01)
Filtration
(27) M W AT
AT M (26)
(24) M
TS - 03
W W DMT DMT
Gambar A.8 Aliran Proses pada Tangki Separator (TS-03) Alur 24
Komponen N =
F Mr Z =
i i i i
AT 3,6707 166,1280 0,0221 0,0001 M 9759,6089 32,0420 304,5880 0,8774
W 763,5372 18,016 42,3811 0,1221 DMT 27,0528 194,18 0,1393 0,0004
347,1305 Σ
Kesetimbangan
o
Trial T = 75 C (348,15 K) ; P = 1 atm (760mmHg) ; L/G = 0,00434
o y = m AT AT
P AT AT = m =
AT
P
y = 0,0000 AT
4,1406e 08 m =
AT
=
0,0001 (1+ )
0,00434 760
AT = 5,45e 11+
0,00434 =4,1406e-08 m AT =5,45e 11 mmHg
o y
=
= m M M
P
M M
m M = P
y = 0,8787 M
1133,2285 m = = M
0,8777 (1+ )
0,00434 760
M =
1,49109+0,00434 = 1133,2285 m =1,49109
M
mmHg
o y
=
= m
P m = P
y = 0,1213
304,1205 m = =
0,1218 (1+ )
0,00434 760
= 0,400159+ 0,00434
= 304,1205 m =0,400159 mmHg
o y = m DMT DMT
P = DMT DMT m =
DMT
P
y = 0,0000 DMT
0,00004 (1+ )
0,00434 0,2332
=
DMT =
m =
DMT 0,000+
0,00434 760
= 0,2332 m =0,0000 mmHg DMT
Σ = 1,000 Σ = 1,0000
Neraca Massa Total :
26
27
2
- N = L
2
27
2 N = L
26
27 L = N
= 0,00434
26 L = 347,1305 345,6304
= 0,00434
kmol
26 L
1,5001
jam
= 0,00434 = 1,004346 kmol 345,6304 = jam Neraca Massa Komponen : AT :
AT
27
= DMT L Mr DMT
26
DMT
= 755,5569 kg jam DMT :
27
= 0,1213 345,6304 18,016
27 Mr
26
= y
27
= 5,5814 kg/jam
26
= 0,3031 1,5001 18,016
26
DMT
= 0,0929 1,5001 194,18
26
= 0,0000 345,6304 194,18
Metanol 28,3241 9731,2849 Air 9759,6089 8,1922 755,3450
Alur 24 Alur 26 Alur 27 Asam Tereftalat 3,6707 3,6707
Komponen Masuk (kg/jam) Keluar (kg/jam)
= 0,000 kg jam Tabel A.8 Neraca Massa pada Tangki Separator (TS-03)
27
DMT
27
DMT
27 Mr DMT DMT
DMT
= y
27
DMT
= 27,0303 kg/jam
26
= L Mr
= 9732,2075 kg jam W :
26
AT
= 0,0000 345,6304 166,128
27
27 Mr AT AT
AT
= y
27
= 3,6677kg/jam
27
26
AT
= 0,0147 1,5001 166,128
26
AT
= AT L Mr AT
AT
= 0,0000 kg jam M :
27
M
M
= 0,8787 345,6304 32,042
27
27 Mr M M
= y
27
= 19,2935 kg/jam
M
26
M
= 0,5893 1,5001 32,042
26
M
= M L Mr M
26
Dimetil Tereftalat 763,5372 27,0528 subtotal 27,0528 67,2398 10486,6298 total 10553,8697 10553,8697
A.2.9 Rotary Dryer (RD-01)
Fungsi : Untuk mengurangi kadar metanol hasil padatan DMT sampai 0,05 %
(31) (28)
Udara M W W Udara
AT AT
(29) (25)
M M
RD - 01
W W DMT DMT
Gambar A.9 Aliran Proses pada Rotary Dryer (RD-01) Fraksi Massa
Komponen Alur 25 x
i
AT 19,3919 0,0023 M 778,0732 0,0925
W 60,8721 0,0072 DMT 7555,6095 0,8980
Σ = 8413,9466 Σ=1,0000 Sisa cairan dalam padatan = 0,05%
25
25
- Σ padatan =
AT DMT
= 19,3919 + 7555,6095 = 7575,0014 kg/jam
99,95 0,05 =
Σ padatan Σ cairan 99,95 0,05
= 7575,0014 Σ cairan Σ cairan = 3,7894 kg/jam
28 Udara pengering (0,3% W) =
4,3960 kg/s = 15825,6 kg/jam
28
28
28
28
= 47,4768 kg/jam Neraca Massa Komponen : AT =
= 19,3920 kg/jam M : =
Σ cairan x ( = 778,0732 + 60,8721
- – 3,7894 x ( = 774,5587 kg/jam = = 778,0732
- – 774,5587 = 3,5150 kg/jam
W : = ) + = 778,0732 + 60,8721
- – 774,5587 + 47,4768 = 108,0098 = = 60,8721 + 47,4768
- – 108,0098 = 0,2744 kg/jam
DMT = = 7555,6095 kg/jam
Tabel A.9 Neraca Massa pada Rotary Dryer (RD-01) Keluar (kg/jam)
Masuk (kg/jam) Komponen
Alur 31 Alur 25 Alur 28 Alur 29
Asam Tereftalat 19,3919 19,3919 Metanol 778,0732 3,5144 774,5587
Air 60,8721 47,4768 0,2750 108,0739 Dimetil Tereftalat 7555,6095 7555,6095
Udara 15825,6 15825,6 subtotal 8413,9464 15873,077 7578,7908 16708,2327 24287,0234 24287,0234 total
A.2.10 Tangki Separator (TS-05)
Fungsi : Memisahkan sebagian metanol dari udara pengering yang berasal dari Rotary Dryer RD-01 (34)
M W Udara
M M
(33) (32)
W
TS - 05
W Udara
Gambar A.10 Aliran Proses pada Tangki Separator (TS-05) Alur 32
Komponen N =
F Mr i Z =
i i i
M 774,5587 32,0420 24,1732 0,0420 W 108,0739 18,016 5,9988 0,0104
Udara 15825,6 29 545,7103 0,9476 575,8824
Σ Kesetimbangan
o
Trial T = -5 C (268,15 K) ; P = 1 atm (760mmHg) ; L/G = 0,03157
o y
=
= m M M
P
M M
m =
M
P
y = 0,020595 M
21,7616 m =
M
=
0,0420 (1+0,03157)
760
M = 0,028634+ 0,03157
= 21,7616 m =0,028634
M
mmHg o y
=
= m
P m = P
y = 0,001883
5,0992 m = =
0,0104 (1+0,03157)
760
= 0,00671+ 0,03157
= 5,0992 mmHg m =0,00671
y =0,977523 dara
Σ = 1,0000 Σ = 1,0000 kmol jam
- 34
= y
34 Mr M M
34
= 0,020595 558,2581 32,042
M
34
= 368,3902 kg jam W :
33
= L
33
= 0,2807 17,6235 18,016
33
= 89,131 kg/jam
34
34 Mr
34
34
= 0,001883 558,2581 18,016
34
= 18,9429 kg jam Udara :
34
= y
DMT
34 Mr DMT
34
= 0,977523 558,2581 26
34
= 15825,6 kg jam Tabel A.10 Neraca Massa pada Condensor (CD-02)
Komponen Masuk (kg/jam) Keluar (kg/jam)
= y
M
Neraca Massa Total : N
= N
32
= L
33
N
32
34
= L
33
= 0,03157 = 0,03157
575,8824 = 0,03157
575,8824 = 1,03157 558,2581 kmol jam
= L
33
34 L
= 406,1685 kg/jam
33
= 575,8824 558,2581 L
33
17,6235
kmol jam
Neraca Massa Komponen : M :
M
33
= M L
33 Mr M M
33
= 0,7192 17,6235 32,042
M
33
33 Mr
Alur 32 Alur 34 Alur 33 M 774,5587 368,3902 406,1685 W 108,0739 18,9429 89,1310
Udara 15825,6 15825,6 subtotal 16212,9331 495,2995 total 16708,2327 16708,2327
A.2.11 Menara Destilasi (MD-01)
Fungsi : Merecycle sisa metanol yang tidak bereaksi dengan memperoleh hasil metanol dengan kemurnian 99.4 ( % massa ) pada sisi enriching dan membuang air hasil reaksi esterifikasi pada sisi
M (35) stripping
W M (20)
W M
MD-01
(27) W M
(33) W M W
(41) Gambar A.11 Aliran Proses pada Menara Destilasi (MD-01)
Neraca massa total :
46285,4664 + 10486,6298 + 495,2995 = 57267,3957 = 57267,3957 - =
- M
- M
= 55805,112 = 57267,3957 - 55805,112 = 1462,2837
FU - 01
C Gambar A.12 Aliran Proses pada Furnace (FU-01)
o
C menjadi 385
o
Fungsi : Memanaskan vapor metanol ( 99,4 % massa ) dari suhu 96,87
A.2.12 Furnace (FU-01)
Metanol 45347,4508 9731,2849 406,1685 55470,2813 14,6228 Air 938,0156 755,3450 89,1310 334,8307 1447,6609 subtotal 46285,4664 10486,6298 4952995 55805,1120 1462,2837 total 57267,3957 57267,3957
Masuk (kg/jam) Keluar (kg/jam) Alur 20 Alur 27 Alur 33 Alur 35 Alur 41
Tabel A.11 Neraca Massa pada Menara Destilasi (MD-01) Komponen
W : = 55805,112 x 0,6% = 334,8307 kg/jam = 1462,2837 x 99% = 1447,6609 kg/jam
= 55470,2813 kg/jam = 1462,2837 x 1% = 14,6228 kg/jam
Neraca Massa Komponen M : = 55805,112 x 99,4%
55484,9041 = 0,984 +572,673957 54912,23019 = 0,984
(7) (9)
0,994 +( 0,01 (57267,3957 - )
) 45437,4508 + 9731,2849 + 406,1685=
41
M
) + (
35
M
= (
33
27
20
Neraca massa metanol : M
(6)
M W M W M W Tabel A.12 Neraca Massa pada Furnace (FU-01) Masuk (kg/jam) Keluar (kg/jam)
Komponen Alur 7 Alur 6 Alur 9
Metanol 55470,0342 2880,3048 58350,3389 Air 334,8292 17,3861 352,2153 subtotal 55804,8634 2897,6909 58702,5542 total 58702,5542 58702,5542
LAMPIRAN B
PERHITUNGAN NERACA PANAS
Basis Perhitungan : 1 jam operasi Satuan operasi : kJ/jam
o
Temperatur Referensi : 0 C Kapasitas produk : 60.000 ton/tahun
LB.1 Perhitungan Kapasitas Panas
a) Data perhitungan Cp
2
3
4 Cp = a + bT + cT + dT + eT x,T
Kapasitas panas gas ideal ( Cpig ) Data kapasitas panas gas ideal ( Cpig ) metanol dan steam tersedia dalam Appendix D, (Coulson ,1983 ). Sedangkan Cpig Asam Tereftalat dan
Dimetil Tereftalat tidak tersedia di daftar dan harus diestimasi dengan metode Rihani & Doraiswany, ( Coulson,1983 ). Karena campuran gas mendekati sifat ideal maka harga kapasitas panas gas ideal bisa dipakai dalam perhitungan.
Asam Tereftalat Tabel LB.1 Penentuan Konstanta Asam Tereftalat
Ni Jenis Gugus Ni ai Ni bi Ni ci Ni di
- 2 -4 -8
2 -COOH 2(1,4055) 2(3,4632 10 ) 2(-0,2537 10 ) 2(0,6886 10 )
- 2 -4 -8
1 -CH=CH- 1(-3,1210) 1(3,8060 10 ) 1(-0,2359 10 ) 1(0,5504 10 )
- 2
- 4
- 8
- <
- 4
- 8 >1,221
- 2
- 4
- 8
- 2
- 4
- 8
- 2
- 4
- 8
- 2
- 4
- 8 >24
- 8 3 2 DT CT BT A Cp >0,747>24
- 8 >1,221
- 2 >58>2,851
- 3 >59>3,596>24
- 8 >0,7471 10
- 1
- 1
- =A T+ B T C T +
- uap
- uap =A T+ B T C T +
- 2 H O + 2 CH OH
- 48,08 - B
- C
- 57,7979 Perry,1984 D -711 88,4 -148,8049 Kirk Othmer Notasi yang digunakan:
Harga konstanta A, B, C, dan, D untuk Cpig Asam Tereftalat, Metanol, Steam, dan Dimetil Tereftalat :
Tabel LB.3 Harga konstanta A, B, C, dan, D untuk Cpig Komponen A B C D
AT -3,2518 17,5008 10
3,1402 10
Metanol 21,152 7,0920 10
2,2870 10
Steam 32,243 1,923 10
1,055 10
DMT 0,6236 17,011 10
2,187 10
Metanol Cp liquid : 80,57230053 kJ/kmol
o
C Laten heat : 35278 kJ/kmol T norm : 337,75 K H Metanol uap pada saat suhu 64,6 (
: 40482,97061 kJ/kmol
uap =A T+
1
2 B T
2
3 C T
3
4 D T
=
dengan
K kmol kJ Cp
2,187 10
2 -C=CH- 2(-1,4714) 2(3,3842 10
) 2(-0,2371 10
) 2(0,6063 10
) Sum -3,2518 17,5008 10
3,1402 10
Dimetil Tereftalat Tabel LB.2 Penentuan Konstanta Dimetil Tereftalat
Ni Jenis
Gugus Ni ai Ni bi Ni ci Ni di 2 -CH3 2(0,6087) 2(2,1433 10
) 2(-0,0852 10
) 2(1,1350 10
) 2 -COO- 2(2,7350) 2(1,0751 10
) 2(0,0667 10
) 2(-0,0923 10
) 1 -CH=CH- 1(-3,1210) 1(3,8060 10
) 1(-0,2359 10
) 1(0,5504 10
) 2 -C=CH- 2(-1,4714) 2(3,3842 10
) 2(-0,2371 10
) 2(0,6063 10
) Sum 0,6236 17,011 10
4
= Cp
li uid T li uid
Asam Tereftalat
Heat Sublimation : 199,685856 kJ/kmol o
Cp solid : 142000 kJ/kmol C H fusion : 31600 kJ/kmol T Sublim : 298,15 K
o o
H AT uap pada saat suhu 25 C ( : 146992,1464 kJ/kmol C
1
1
1
2
3
4
D T
2
3
4 = Cp T +
li uid usion solid
= Cp
solid T solid
Dimetil Tereftalat
o
T fusion : 50 C
o
cp solid : 271,852 kJ/kmol C
H fusion : 31600 kJ/kmol
o
T nm : 284 C
Panas Laten : 57300 kJ/kmol o
Cp liq : 383,60259 kJ/kmol C
o
H DMT uap pada saat suhu 284 C ( : 192255,6061 kJ/kmol
1
1
1
2
3
4
D T2
3
4 = Cp T +
li uid usion Cp T solid li ud
= Cp
solid T solid LB.1 Fixed Bed Reactor (R-01)
AT AT
Metanol Metanol
H O H O
597,15 K 602,9 K
2
2 DMT
DMT Reaksi esterifikasi Asam Tereftalat dengan Metanol menjadi Dimetil Tereftalat dan Steam : COOH
COOCH
3
2 COOH
3 COOCH
3 Asam Metanol Dimethil Steam
Tereftalat Tereftalat Panas Reaksi Tabel LB.4 Data panas reaksi tiap komponen
o
Solid Panas sublimasi Hf
o o
Gas 25 C
o o Hf
Komponen
25 C
25 C Sumber (kcal / mol)
(kJ / mol) (kJ / mol)
A - 816 142 -161,0899 Kirk Othmer
Perry,1984 -
A = Asam Tereftalat B = Metanol C = Steam D = Dimetil Tereftalat
o
Hr adalah perubahan entalphi reaksi pada suhu 25 C
o o o o
= 2 C D - 2 - B A ΔHr ΔHf ΔHf ΔHf ΔHf
= 29919 , 3872 kJ/kmol = - 7150,9052 kcal/kmol ΔHr
Hr pada berbagai suhu :
T = cp dT
ΔHr ΔHr T
To 298
=
= -39993.16688 (kJ/kmol)
327oC ∆Hr │
Panas Reaksi = x 308249,5277 kmol
∆Hr │ 327oC
Tabel LB.5 . Panas masuk Reaktor pada Alur 14
Input kmol/tahun H (kJ/kmol) Q (kJ/tahun)
AT 321010.2893 162789.4800 52257098080
Metanol 14423041.1578 55085.3340 794498039649.0670
154874.5039 56111.7220 8690275106
H
2 O
1904.7059 195380.2508 372141915.1