LAMPIRAN III PERHITUNGAN SPESIFIKASI ALAT
1.
ACCUMULATOR - 01 (ACC-01)
Fungsi : Tempat menampung kondensat yang berasal dari condensor-01 Tipe
: Silinder horizontal dengan penutup ellipsoidal
Gambar
:
input
ACC - 01
output
Kondisi Operasi: Tekanan
= 0,6 atm
Temperatur
= 82,767 oC
Laju alir
= 93,448.729 kg/jam
Densitas
= 304, 711 kg/m3
Residence Time
= 5 menit
Perhitungan Desain Accumulator - 01 a. Kapasitas Accumulator, Vt Volume liquid
= Laju alir/Densitas x holding time = (93,448.729 kg/jam)/(304, 711 kg/m3) x 0,083
jam = 25,557 m3 Faktor keamanan
= 10%
Kapasitas acc.
= 1,1 x 25,557 m3 = 36,025 m3
b. Desain Ukuran Accumulator
Volume Silinder, Vs Vs
=
4
D 2 .Lsilinder
Lsilinder = 4.D
= . D3
Volume Ellipsoidal, Ve Ve
=
( .D 3 ) 24
Volume Total Accumulator, VT VT
= Vs + 2.Ve = ( . D 3 ) + (2.( = 3,402.D3
Diameter Accumulator, D D
=
3
=
3
VT acc 3,402 28,112 3,402
= 2,022 m Maka, Vs
= 25,950 m3
Ve
= 1,081 m3
VT
= 28,112 m3
c. Panjang Accumulator
Panjang Silinder L
= 4.D = 4 . 2,022 m = 8,087 m
( .D 3 ) )) 24
Panjang Ellipsoidal h
=
1 D 4
=
1 2,022 m 4
= 0,505 m
Panjang Total Accumulator, LT LT
= L + 2h = (8,087 m + (2. 0,505 m)) = 9,098 m
d. Tebal Dinding Accumulator
Ketebalan Dinding Bagian Head, thead t =
P . Da Cc 2.S .Ej 0,2.P
Dimana: t
= ketebalan dinding bagian head, m
P = tekanan design
= 8,818 psi
Da = diameter vessel
= 79,598 in
S = working stress yang diizinkan = 13.700 psi C = faktor korosi yang diizinkan
= 0,013 in
Ej = faktor efisiensi pengelasan
= 0,850
Maka didapatkan: t =
(8,818 psi )(79,598 in ) 0,013 in (2 x13.700 x0,85) (0,2 x8,818 psi )
= 0,028 in = 0,001 m
Ketebalan Dinding Bagian Silinder, tsilinder t =
P . ri Cc S .Ej 0,6.P
Dimana: ri
= 49,028 in
Maka didapatkan: t =
(8,818 psi )(79,598in ) 0,013 in (13.700 0,85) (0,6 8,818 psi )
= 0,028 in = 0,001 m
OD
= ID + 2.tsilinder = (2,022 + (2. 0,001)) m = 2,023 m
Ringkasan spesifikasi Accumulator-01 (ACC-01) IDENTIFIKASI Nama Alat
Accumulator-01
Kode
ACC-01
Jumlah
1 buah
Fungsi
Menampung kondensat dari condensor-01 DATA DESAIN
Tipe
Silinder horizontal dengan ellipsoidal head
Kapasitas
25,557 m3
Tekanan
0,600 atm
Temperatur
82,767 oC
Diameter
2,022 m
Panjang
9,098 m
Tebal Dinding
0,001 m
Bahan Konstruksi
Carbon steel
Dengan Perhitungan yang sama untuk Accumulator selanjutnya analog dengan perhitungan Accumulator ACC-01. 2.
ACCUMULATOR - 02 (ACC-02) IDENTIFIKASI
Nama Alat
Accumulator-02
Kode
ACC-02
Jumlah
1 buah
Fungsi
Menampung kondensat dari condensor-02 DATA DESAIN
Tipe
Silinder horizontal dengan ellipsoidal head
Kapasitas
4,469 m3
Tekanan
0,370 atm
Temperatur
55,071 oC
Diameter
1,131 m
Panjang
5,087 m
Tebal Dinding
0,000462 m
Bahan Konstruksi
Carbon steel
3.
ADSORBER-01 (AD-01/02)
Fungsi
: Untuk menghilangkan atau menyerap kandungan H2O keluaran dari Kolom Destilasi-01 (KD-01)
Tipe
: Silinder vertikal dengan ujung ellipsoidal
Gambar
:
a. Data Temperatur, T
=82,767 °C
Tekanan, P
= 0,6 atm
Laju alir massa, W
= 42931,198
Densitas campuran
= 0,928
Faktor keamanan
= 10%
Adsorbtion time
= 0,500 jam
b. Kapasitas Kolom, Vk V
=
Laju alir massa × t Densitas
= 23141,008 m3 Vk
= (1 + f) × k = 25455,109 m3
kg m3
kg jam
c. Volume Packing, Vp Dalam adsorber-01/02 ini diharapkan bahwa semua H2O yang terdapat di dalam produk keluaran Kolom destilasi-01 dapat terserap seluruhnya sehingga tidak ada vapor H2O yang akan terbawa karena dikhawatirkan terjadinya reaksi balik. Kemampuan penyerapan silica gel terhadap H2O yang dihasilkan adalah 420,656 kg silica gel/kg H2O. Sedangkan untuk menentukan Volume Packing (Vp) yang dibutuhkan yaitu: Diketahui jumlah uap air yang akan di serap sebesar 2148,416 kg dan faktor penyerapan (Fa) adalah 0,014 maka jumlah adsorben yang digunakan: Wp
= Fa × Wa = 323,582 kg
Excess silica gel
= 97,074 kg
Total silica gel
= Wp + excess zeolit = 323,582 kg + 97,074 kg = 425,656 kg
Sehingga untuk kebutuhan penyerapan 8 jam, dibutuhkan silica gel sebanyak: Wpt
= Total silica gel x 8 jam = 425,656 kg x 8 jam = 3365,248 kg
Volume packing, Vp Vp
=
Wpt ρcampuran
(Pers. 16.4 Perry, 1997)
= 3627,908 m3 Tinggi packing, Tp
=
4 × Vp π × D2
= 31,870 m Pemasangan bed Packing yakni 7,484 meter di atas dasar Adsorber (Muklis, 2012). d. Volume Total Desiccantor Volume total
= Vk + Vp = 398,631 m3
e. Diameter Kolom Adsorber (Tabel 10-64, Volume of Partially Filled Horizontal Cylinder, Perry, 1997) Volume bagian Silinder, Vs Vs
= π Dt2 Hs
Hs
3
= Dt 2
3
= π Dt2 ( Dt) 2
3
= π Dt3 8
Volume bagian Ellipsoidal, VE π
VE = Dt2 He
He
6
π
1
6
4
= Dt2 ( Dt) =
π 12
Dt3
Sehingga, Vt
= Vs + Ve = 1,440 Dt3
Dt
= (Vt/1,440)1/3
Dt
= 12,042 m
Sehingga, jari-jari tangki (R) = 6,021 m f. Tinggi Tangki Tinggi silinder, Hs Hs
3
= Dt 2
= 15,063 m Tinggi ellipsoidal, He He
1
= Dt 4
= 3,011 m Tinggi Total, Ht
(Treyball, Pers. 3.9, 1981)
= Hs + He = 18,074 m
1
= Dt 4
g. Tebal Dinding t
=(
P×D
2 S E - 0,2 P
)+C
(Tabel. 4, Peters and Timmerhaus)
Dimana : Tekanan design, P
= 0,6 atm
Diameter vessel, D
= 12,042 m
Working stress allowable, S
= 932,230 m
Joint efficiency, E
= 0,850 m
Korosi maksimum, C
= 0,0003 m
P×D
t
=(
t
= 0,005 m = 0,489 cm
2 S E - 0,2 P
)+C
h. Outside Diameter OD = D + 2t = 12,052 m IDENTIFIKASI Nama Alat
Adsorber-01 (DS-01/02)
Kode
AD-01
Jumlah
1 buah
Fungsi
Untuk menyerap air keluaran dari kolom destilasi-01 DATA DESAIN
Tipe
Silinder vertikal dengan ujung ellipsoidal
Kapasitas
3627,908 m3
Adsorben
Silica Gel
Tekanan
0,600 atm
Temperatur
82,767 oC
Diameter
12,042 m
Tinggi
18,074 m
Tebal Dinding
0,489 m
Bahan Konstruksi
Carbon steel
4.
CONDENSER - 01 (CD-01)
Fungsi : Mengkondesasikan Top produk KD-01 Tipe
: Shell and Tube Heat Exchanger
Gambar
: Aliran inlet Tube
Shell
Rear End
Head
Aliran outlet
Fluida Panas
Water in
:
Top produk KD-01
W
= 93.448,729 kg/hr
= 206. 018,938 lb/hr
T1
= 82,767 oC
= 180,981 oF
T2
= 82,767 oC
= 180,981 oF
Fluida Dingin
:
Air
w
= 297.253,863 kg/hr = 655.331.811 lb/hr
t1
= 28oC
= 82,4oF
t2
= 50oC
= 122oF
Perhitungan design sesuai dengan literatur pada buku Donald Q. Kern (1965). 1.
Beban Panas CD-01 Q
= 27.374.702,744 kJ/hr = 25.702.434,670 Btu/hr
2.
LMTD
Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
180,981
Suhu tinggi
122,000
58,981
180,981
Suhu rendah
82,400
98,581
Selisih
-39,6
LMTD =
t 2 t1 ln (t 2 / t1 )
= 77.094 oF Ft
=1
t
= 77.094 oF
3.
(Fig.18, Kern)
Temperatur Rata-rata Tavg =
T1 T 2 2
= 180.981 oF tavg
=
t1 t 2 2
= 102,200 oF 4.
Menentukan luas daerah perpindahan panas Asumsi UD = 210 Btu/hr.ft2.oF A
=
Q U D . t
=
25.702.434,670 150 47,697
(Tabel 8, Kern)
= 2,932.691 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger 5.
Spesifikasi tube dan shell
Tube Side
= Aliran top produk KD-01
Panjang tube (L)
= 19 ft
Outside Diameter (OD) = 1 in BWG
= 18
Pass
=2
a”
= 0,262 ft2/lin ft A = L x a" 2,932.691 = 19 0,262
Jumlah tube, Nt
= 589,580
Dari tabel.9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt
= 589,580
Corrected Coefficient, UD A
= Nt x L x a'' = 589,580 x 19 ft x 0,262 ft2 = 2,932.691
UD
=
Q U D . t
= 149,319 karena nilai Ud perhitungan mendekati nilai Ud asumsi, maka data untuk shell : Shell
= Air/pendingin
ID
= 39 inch
(Tabel 9, Kern)
Baffle Space (B = ID/5) = 19,5 inch Pass
=2
Pt
= 1,25 in triangular pitch
6.
Perhitungan desain bagian tube
Flow Area/tube, a’t a’t
= 0,902 in2
(Tabel 10, Kern)
at
=
Nt a ' t 144 n
(Pers. 7.48, Kern)
=
589,580 0,902 144 2
= 1,882 ft2
Laju Alir, Gt Gt
= W/at =
206.018,938 1,882
= 109.450,484 lb/hr.ft2
Bilangan Reynold, Ret μ
= 0,010 cp
ID
= 0,902 inch = 0,075 ft
Ret
= ID.Gt/ μ =
= 0,025 lb/ft hr (Tabel 10, Kern)
0,075 109.450,484 / 0,010 0,025
= 322.801,472
Dengan L/D = 252,782 diperoleh Jh = 600
(Fig.24, Kern)
Nilai hi CP
= 15,678 Btu/lb.oF
k
= 0,012 Btu/hr ft.oF
c. k
= 5,770
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
0 ,14
=1
0,012 1/ 3 = 252,782 3,491 0,075 = 140,728 Btu/hr ft2 oF
hio
= hi x ID/OD
(Pers. 6.5, Kern)
= 126,937Btu/hr.ft2.oF 7.
Perhitungan desain bagian shell ID = Diameter dalam shell
= 39 in
B = Baffle spacing
= 19,5 in
Pt = tube pitch
= 1,25 in
C’ = Clearance
= Pt – OD = 1,25 – 1 = 0,250 in
Flow Area, as as
= ID x C’B/144 PT =
39 0,250 19,5 144 1,25
= 1,056 ft2
Laju Alir, Gs Gs
= w/as =
655,331.811 1,056
= 620,432.484 lb/hr.ft2
Bilangan Reynold, Res de
= 0,902 in
(Fiq.28 Kern)
De (Equivalent diameter) = 0,06 ft μ
= 0,011 cp
Res
= =
= 0,025 lb/ft hr
GS De
620,432..484 x0,060 0,282
= 132 ,158.142 Maka: jH
= 140
Nilai ho Cp
= 176,447 Btu/lb.oF
k
= 0,259 Btu/hr ft.oF
(Fig.28, Kern)
Cp. k
1
3
= 5,770
Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3\
0,259 x14,262 0,06
= 140 x
= 398,871 Btu / hr ft2 oF
8.
Clean Overall Coefficient, UC UC
=
hio ho hio ho
=
126,937 x398,871 126,937 398,871
= 96,293 Btu/hr.ft2.oF
9.
Dirt Factor, Rd Rd
=
U C U D U C U D
=
146,319 96,293 149,319 x96,293
= 0,004 hr.ft2.oF/Btu 10.
Pressure drop Bagian tube
Untuk NRe
= 322,801.472
Faktor friksi
= 0,00012
s
= 0,108
ΔPt
=
f Gt 2 L n 5, 22 x 10 10 x De s f t
(Fig 26, Kern)
=
0,00012 x109,450.484 2 x19 x(2) 5,22 1010 x0,075x0,108x1
= 0,129 psi V2 / 2g
= 0,004
ΔPr
= ( 4n/s ) ( V2/2g )
(Fig 27, Kern)
= 0,149 Psi ΔPT
= ΔPt + ΔPr = 0,129 psi + 0,149Psi = 0,278 psi
Shell Side Re
= 132,158.142
f
= 0,0005
N+1
= 12 L / B
(Fig.29, Kern)
= 12 x (228/19,5) = 140,308 Ds
= 3,250 ft
s
=1
ΔPs
=
fGs2 Ds ( N 1) 5,22 1010 Desf s
0,0005x620,432.484 2 x3,250 x(140,308) 5,22 1010 x0,060 x1 = 0,028 psi
IDENTIFIKASI Nama Alat
Condenser – 01
Kode
CD – 01
Jumlah
1
Fungsi
Untuk mengkondensasikan top KD – 01
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
96,293
Btu/hr ft2 oF
Ud
149,319
Btu/hr ft2 oF
Rd Calculated
0,004
hr ft2 oF/Btu
TUBE SIDE Length
19
Ft
OD
1
In
Passes
2
BWG
18
Pitch
1,250
Nt ΔPT
601 0,278
in Triangular Pitch tubes Psi SHELL SIDE
ID
39
in
B
19,5
in
Passes ΔPs
2 0,028
psi
Dengan Perhitungan yang sama untuk Accumulator selanjutnya analog dengan perhitungan Condenser-01 (CD-01). 5.
CONDENSER - 02 (CD-02) IDENTIFIKASI
Nama Alat
Condensor – 02
Kode
CD – 02
Jumlah
1
Fungsi
Untuk mengkondensasikan top KD – 02
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
241,610
Btu/hr ft2 oF
Ud
126,710
Btu/hr ft2 oF
Rd Calculated
0,004
hr ft2 oF/Btu
TUBE SIDE Length
12,550
Ft
OD
1
In
Passes
2
BWG
18
Pitch
1,250
Nt ΔPT
605 10,440
in Triangular Pitch tubes Psi SHELL SIDE
ID
37
in
B
18,5
in
Passes ΔPs
2 2,407
psi
6.
COOLER - 01 (C-01) Fungsi
: Menurunkan suhu keluaran R-01 menuju PC-01
Tipe
: Double Pipe Heat Exchanger
Gambar
:
Fluida Panas
Fluida Dingin
: Keluaran R-01 W
= 66804,593 kg/jam = 39441,925 lb/jam
T1
= 274,726 oC
= 526,507 oF
T2
= 234,818 oC
= 454,672 oF
: Air W
= 102249,854 kg/jam = 225422,0726 lb/jam
t1
= 28 oC
= 82,4 oF
t2
= 50 oC
= 122 oF
Perhitungan: 1. Beban Panas C-01 Q = 9416393,534 kJ/jam = 8925149,699 Btu/jam 2. LMTD Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
526,507
Suhu tinggi
122
404,507
454,672
Suhu rendah
82,4
372,272
Selisih
32,234
LMTD
t 2 t1 = 388,166 oF ln (t 2 / t1 )
=
(Coulson & Richardson, 2005), Hal. 752 Ft = 1,000
(Coulson & Richardson, 2005), Grafik 12.19
Ft x LMTD
= 388,166 oF
Tc = T avg
= 490,590 oF
tc = t avg
= 102 oF
Asumsi UD = 135 Btu/hr,ft2,oF Q A = U D . t
(Kern, 1957), Tabel 8, Hal 840
A = 170,319 ft2 Karena A > 200 ft2, maka dipilih HE jenis Double Pipe Heat Exchanger, Rencana Klasifikasi Data Pipa
Outer Pipe
Inner Pipe
IPS (in)
10
8
SN
40
40
OD (in)
10,75
8,625
ID (in)
10,02
7,981
a” (ft2/ft)
2,814
2,258
Cold Fluid (Air) : Annulus a.
Flow Area, aa D1 = 10,02 in = 0,835 ft D2 = 8,625 in = 0,719 ft aa = =
4
4
(D22 – D12) (0,172 2 – 0,138 2) = 0,008 ft2
Equivalent Diameter, De De =
D
2 2
D1 D1
2
= 0,2513 ft
(Kern, 1957), Eq. 6.3
b. Kecepatan Massa, Ga Ga = W/aa = 1589837,288 lb/hr,ft2 c.
Reynold number, Re Pada tavg = 102,2 oF μ
= 0,664 lb/hr ft
Rea
= De,Ga/μ =
0,2513 𝑥 1589837,288 0,664
= 248636,841
JH
= 600
k
= 0,3642 Btu/hr.ft2(oF/ft)
cp
= 0,0037 Btu/lb.oF
c Pr = k
1
(Kern, 1957), Fig. 24
3
= 0,2533 d. Koefisien perpindahan panas k c = JH De k
ho
1
3
w
0 ,14
= 220,258 Btu/hr,ft2,oF Hot Fluid (Keluaran RB-02) : Inner Pipe a. Flow Area, ap D = 7,981 in = 0,6651 ft ap =
4
D2
=
4
(0,6651)2 = 0,3472 ft2
b. Kecepatan Massa, Gp Gp = w/ap
= 424148,836 lb/hr ft2
c. Reynold number, Re Pada Tavg = 490,6 oF μ
= 0,0181 cP
= 0,0438 lb/hr
Rep = D x Gp/μ =
424148,836 x 7,981 0,0181
= 6436659,383
JH = 1000
(Kern, 1957), Fig. 24
= 0,0778 Btu/hr,ft2(oF/ft)
d. k
cp = 0,0026 Btu/lb,oF c Pr = k
1
3
= 0,1133 k e. hi = JH De
c k
1
3
w
0 ,14
= 13,2618 Btu/hr,ft2,oF f. Koreksi hi pada permukaan OD hio = hi x ID/OD = 12,2716 Btu/hr,ft2,oF g. Clean Overall Coefficient, UC UC
=
hioxho = 11,624 Btu/hr,ft2,oF hio ho
h. Design Overall Coefficient, UD 1 1 Rd U D UC
(Kern, 1957), Eq. 6.10
Rd ditentukan 0,002 untuk masa servis 1 tahun 1 𝑈𝐷
=
1 𝑈𝐶
+ 0,002
UD = 11,359 Btu/hr,ft2,oF i. Required Length Q A = U . t D = 2024,057 ft2 Dari tabel 11 Kern, untuk 10-in IPS standard pipe, external surface/foot length = 2,258 ft Required length =
2024,057 ft2 2,258 ft
= 896,394 ft
Diambil panjang 1 harpin = 20 ft Jumlah harpin yang dibutuhkan =
896,394 40
= 22,41
Maka, dipakai 22 harpin 20 ft Actual Length
= 22 x 20 ft x 2 = 896 ft
Actual Surface = L x a” = 2024,0571 ft2 j. Actual Design Coefficient, UD UD =
Q A. t
= 11,36 Btu/hr,ft2,oF k. Dirt Factor, Rd Rd =
U C U D U C U D
= 0,002 hr,ft2,oF/Btu PRESSURE DROP Cold Fluid : Annulus a. De’ = (D2 – D1) = 0,1163 ft NRe = 248636,8407 0,264 ƒ = 0,0035 (Re a) 0, 42 = 0,0049 ρ b. Fa
= 61,94 lb/ft3 =
4 fGa2 L 2 g 2 De
= 8,7453 ft c. V
=
G = 7,1298 ft/s 3600
Fl
V 2 = 3 x = 1,5787 ft 2g
Pa
=
( Fa Fl ) 144
(Eq, 3,47b, (Kern, 1957))
= 4,4408 psi
Hot Fluid: Inner Pipe a. Rep = 6436659 ƒ ρ
0 , 264 (Re p ) 0 , 42 = 3,615 lb/ft3 0 ,0035 = 0,0039
(Eq, 3,47b, (Kern, 1957))
4 fGp 2 L 2 b. ΔFp = 2 g D = 343,0956 ft
Pp
Fp . = 144
= 8,6131 psi Identifikasi Nama Alat
Cooler-01
Kode Alat
C-01
Uc
11,624 Btu/hr ft2 oF
Ud
11,360 Btu/hr,ft2,oF
Rd
0,002 hr ft2 oF/Btu
Tipe
Double Pipe Heat Exchanger
Fungsi
Menurunkan temperatur keluaran R-01
Jumlah
1 Unit Inner Tube
Length
896 ft
OD
7,981 in
ΔPI
8,6131 psi Outer Tube
ID ΔPO
2,067 in 4,4408 psi
7.
COOLER – 02 (C-02) Fungsi
: Menurunkan suhu keluaran R-01 menuju PC-01
Tipe
: Double Pipe Exchangers
Gambar
:
Fluida Panas
Fluida Dingin
: Keluaran R-01 W
= 66804,593 kg/jam = 147278,7418 lb/jam
T1
= 234,818 oC
= 454,672 oF
T2
= 194,910 oC
= 382,838 oF
: Air W
= 99775,417 kg/jam = 219966,880 lb/jam
t1
= 28 oC
= 82,4 oF
t2
= 50 oC
= 122 oF
Perhitungan: 1. Beban Panas C-02 Q = 9188517,718 kJ/jam = 8709161,937 Btu/jam 2. LMTD Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
454,672
Suhu tinggi
122
322,672
382,838
Suhu rendah
82,4
300,438
Selisih
32,234
LMTD
t 2 t1 = 316,281 oF ln (t 2 / t1 )
=
(Coulson & Richardson, 2005), Hal. 752 Tc = T avg
= 418,755 oF
tc = t avg
= 102 oF
Asumsi UD = 145 Btu/hr.ft2.oF Q A = U D . t
(Kern, 1957), Tabel 8, Hal. 840
= 189,9042 ft2 Karena A < 200 ft2, maka dipilih HE jenis Double Pipe Exchangers Rencana Klasifikasi
Data Pipa
Outer Pipe
Inner Pipe
IPS (in)
12
10
SN
30
40
OD (in)
12,75
10,75
ID (in)
12,09
10,02
a” (ft2/ft)
3,338
2,814
Cold Fluid (Air) : Annulus a. Flow Area, aa D1 = 10,75 in = 0,8958 ft D2 = 12,09 in = 1,0075 ft aa = =
4
4
(D22 – D12) (1,0075 2 – 0,8958 2) = 0,1668 ft2
Equivalent Diameter, De
D De =
2 2
D1 D1
2
= 0,2373 ft
b. Kecepatan Massa, Ga
(Kern, 1957), Eq. 6.3
Ga = W/aa = 1318406,1877 lb/hr,ft2 c.
Reynold number, Re Pada tavg = 102,2 oF μ
= 0,664 lb/hr ft = De,Ga/μ
Rea
=
0,2373 x 1318406,1877 0,664
= 194660,115
JH
= 500
k
= 0,3642 Btu/hr.ft2(oF/ft)
cp
= 0,0037 Btu/lb.oF
c Pr = k
1
(Kern, 1957), Fig. 24
3
= 0,2533 d. Koefisien perpindahan panas k c = JH De k
ho
1
3
w
0 ,14
= 194,4172 Btu/hr,ft2,oF Hot Fluid (Keluaran R-01) : Inner Pipe a. Flow Area, ap D = 10,02 in = 0,835 ft ap =
4
D2
=
4
(0,835)2 = 0,5473 ft2
b. Kecepatan Massa, Gp Gp = w/ap
= 269089,9374 lb/hr ft2
c. Reynold number, Re Pada Tavg = 418,8 oF μ
= 0,0167 cP
= 0,0403 lb/hr
Rep = D x Gp/μ =
0,835 x 269089,9374 0,0167
= 5573058,093
JH = 1000
(Kern, 1957), Fig. 24
= 0,071 Btu/hr,ft2(oF/ft)
d. k
cp = 0,0031 Btu/lb,oF
c Pr = k
1
3
= 0,1201 k e. hi = JH De
c k
1
3
w
0 ,14
= 10,2154 Btu/hr,ft2,oF f. Koreksi hi pada permukaan OD hio = hi x ID/OD = 9,5217 Btu/hr,ft2,oF g. Clean Overall Coefficient, UC UC
=
hioxho = 9,0771 Btu/hr,ft2,oF hio ho
h. Design Overall Coefficient, UD 1 1 Rd U D UC
(Kern, 1957), Eq. 6.10
Rd ditentukan 0,002 untuk masa servis 1 tahun 1 𝑈𝐷
=
1 9,0771
+ 0,002
UD = 8,9153 Btu/hr,ft2,oF i. Required Length Q A= U D . t = 3088,643 ft2 Dari tabel 11 Kern, untuk 10-in IPS standard pipe, external surface/foot length = 2,814 ft Required length =
3088,643 ft2 2,814 ft
= 1097,5989 ft
Diambil panjang 1 harpin = 20 ft
Jumlah harpin yang dibutuhkan =
1097,5989
40
= 27,44
Maka, dipakai 27 harpin 20 ft Actual Length
= 27 x 20 ft x 2 = 1098 ft
Actual Surface = L x a” = 3088,6433 ft2 j. Actual Design Coefficient, UD UD =
Q A. t
= 8,9153 Btu/hr,ft2,oF k. Dirt Factor, Rd Rd =
U C U D U C U D
= 0,002 hr,ft2,oF/Btu PRESSURE DROP Cold Fluid : Annulus a. De’ = (D2 – D1) = 0,1117 ft NRe = 194660,1147 0,264 ƒ = 0,0035 (Re a) 0, 42 = 0,0051 ρ b. Fa
= 61,94 lb/ft3 =
4 fGa2 L 2 g 2 De
= 7,90703025 ft c. V
Fl
=
G = 5,9126 ft/s 3600
V 2 = 3 x = 1,0857 ft 2g
(Eq, 3,47b, (Kern, 1957))
Pa
=
( Fa Fl ) 144
= 3,8681 psi Hot Fluid: Inner Pipe a. Rep = 5573058 ƒ ρ
0 , 264 (Re p ) 0 , 42 = 2,392 lb/ft3 = 0,0039 0 ,0035
b. ΔFp =
(Eq, 3,47b, (Kern, 1957))
4 fGp 2 L 2 g 2 D
= 309,422 ft
Pp
Fp . = 144
= 5,1398 psi
Identifikasi Nama Alat
Cooler-02
Kode Alat
C-02
Uc
9,0771 Btu/hr,ft2,oF
Ud
8,9153 Btu/hr,ft2,oF
Rd
0,002 hr,ft2,oF/Btu
Tipe
Double Pipe Heat Exchanger
Fungsi
Menurunkan temperatur keluaran R-01
Jumlah
1 Unit Inner Tube
Length
1098 ft
OD
10,75 in
ΔPI
5,1398 psi Outer Tube
ID ΔPO
12,09 in 3,8681 psi
8.
COOLER - 03 (C-03) Fungsi
: Menurunkan suhu keluaran R-01 menuju PC-01
Tipe
: Shell and Tube Exchangers
Gambar
:
Fluida Panas
Fluida Dingin
: Keluaran R-01 W
= 66804,593 kg/jam = 147278,7418 lb/jam
T1
= 194,910 oC
= 382,838 oF
T2
= 155,000 oC
= 311,000 oF
: Air W
= 97264,051 kg/jam = 214430,274 lb/jam
t1
= 28 oC
= 82,4 oF
t2
= 50 oC
= 122 oF
Perhitungan: 1. Beban Panas C-03 Q = 9188517,718 kJ/jam = 8709161,937 Btu/jam 2. LMTD Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
382,838
Suhu tinggi
122
260,838
311,000
Suhu rendah
82,4
228,600
Selisih LMTD
=
32,238
t 2 t1 = 244,365 oF ln (t 2 / t1 )
(Coulson & Richardson, 2005), Hal. 752 Ft = 1,00
(Coulson & Richardson, 2005), Grafik 12.19
Ft x LMTD = 244,365 oF Tc = T avg = 346,919 oF tc = t avg = 102 oF Asumsi UD A =
= 80 Btu/hr,ft2,oF Q U D . t
(Kern, 1957), Tabel 8, Hal. 840
A = 445,5002 ft2 Karena A > 200 ft2, maka dipilih HE jenis Sheel and Tube, Rencana Klasifikasi Tube Side : Panjang Tube (L)
= 16 ft
Outside Diameter (OD)
= 1,5 inch
BWG
= 18
Pass
=2
a"
= 0,3925 A = L x a"
Jumlah Tube (Nt) Nt
= 70,9395
Tube sheet
= 1,875 triangular pitch
(Kern, 1957), Tabel 10, Hal 843
dari tabel 9 Kern, didapat Jumlah Tube (Nt) yang mendekati adalah Nt
= 72
Koreksi UD A
= Nt x L x a'' = 452,160 ft2
UD =
Q A .Δt
UD = 78,8217 Btu/hr ft2 oF
(koreksi memenuhi)
Karena nilai Ud perhitungan sama dengan nilai Ud asumsi, maka data untuk Shell yaitu : Shell side : ID
= 21,25 inci
Baffle Space (B )
= ID/2= 10,625 inci
Pass (n)
=2
Pt
= 1,875
Hot Fluid (keluaran FT-01) : Tube Side 1. Flow area per Tube (at') = 1,54 in2 Total flow area (at)
= Nt x a't / 144 x n = 0,385 ft2
2.
Laju alir, Gt
= W / at = 382542,1865 lb/(hr) (ft2)
3.
Bilangan Reynold, Ret Pada Tavg
= 346,919 oF
Viskositas ( μ )
= 0,0152 cp
= 0,0368 lb/ft hr
ID
= 1,40 in
= 0,1167 ft
Re
= D x Gt / μ = 2932320,7466
4.
L/D
= 16 ft / 1,40 ft = 137,143
jH 5.
6.
= 1000
Prandl Number ( Pr )
(Kern, 1957), Fig, 24, Hal. 834
cp x k
=
k
= 0,0640 Btu/hr ftoF
Cp
= 0,0028 Btu/lboF
Pr
= 0,0016
Dengan (μ/μw) = 1 untuk bahan kimia kecuali untuk hidrokarbon, Koreksi viskositas diabaikan karena tidak signifikan, maka didapat : hi j H
k Cp D k
1
3
w
0 ,14
hi
= 64,5256 Btu/hr ft2oF
hio
= hi (ID / OD) = 60,224 Btu/hr ft2oF
Cold Fluid (Air): Shell Side Suhu rata-rata
= 102,2oF
Baffle spacing (B)
= 10,625 in
Clerance (C')
= pitch – OD = 1,875 – 1,5 = 0,375
1. Luas area laluan (as)
= (ID x C' x B) / (144 Pt) = 0,3136 ft2
2.
Laju alir, (Gs)
= W / as = 683802,5616 lb/hr ft2
3.
Reynold Number (Res) = D x Gs / μ Pada tavg
= 102,2oF
Viskositas (u)
= 0,664 cp = 1,607 lb/ft hr
Diameter ekivalen (De) = 1,08 in = 0,09 ft = D x Gt / μ
Jadi, Re
= 38299,2075 4.
JH
= 140
(Kern, 1957), Fig, 28, Hal. 838
5.
k
= 0,3642 Btu/hr ft0F
Cp
= 0,0037 Btu/lb 0F
Prandl Number ( Pr )
Cp x = k = 0,0163
6.
Koreksi viskositas diabaikan karena tidak significant, maka didapat : ho jH
k De
Cp k
1
3
w
0 ,14
= 143,5032 Btu/hr ft2 °F
ho 7.
Clean overall coefficient Uc = (hio x ho) / (hio + ho) = 42,421 Btu/hr ft2 0F
8.
Dirt factor, Rd Rd = (UD - Uc ) / (Uc x UD) = 0,0109
PRESSURE DROP Tube side 1. Untuk NRe
= 2932320,7466
Faktor friksi ( f ) = 0,0001
2.
s
= 0,2766
Pt
=
(Kern, 1957), Fig, 26
f Gt 2 L n 5, 22 x 10 10 x De s f t
= 0,139 psi 3.
Gt
= 382542,1865 lb/(hr) (ft2)
V2/ 2g
= 0,054 psi
Pr
= (4n / s) (V2/ 2g)
(Kern, 1957), Fig, 27
= 1,5621 psi 4.
PT
= Pt + Pr = 1,7011 psi
Shell Side 1.
Untuk NRe
= 38299,2075
Faktor friksi ( f )
= 0,0002
(Kern, 1957), Fig, 29
Number of cross, (N+1) N+1
(Kern, 1957), Eq 7.43
= 12 L / B = 216,8471
2.
s
= 1,000
Ps
=
f G s Di ( N 1) 5,22 x 1010 x De S f s 2
= 5,733 psi
Identifikasi Nama Alat
Cooler-03
Kode Alat
C-03
Uc
42,4211 Btu/hr ft2 oF
Ud
78,8217 Btu/hr ft2 oF
Rd
0,0109 hr ft2 oF/Btu
Tipe
Shell and Tube Heat Exchanger
Fungsi
Menurunkan temperatur keluaran R-01
Jumlah
1 Unit Tube Side
Length
16 ft
OD
1,5 in
Passes
2
BWG
18
Pitch
1,875 in (Triangular Pitch)
Nt
72
ΔPT
1,7011 psi Shell Side
ID
21,25 in
B
10,625 in
Passes ΔPs
2 5,733 psi
9.
EKSPANDER - 01 (EP-01) Fungsi
:
Menurunkan tekanan gas Hidrogen keluaran FD-01
Bentuk
:
Turbin
Gambar
: out E-01 10. in
a.
Data
Laju alir massa, W
= 5709,431 = 95,157
Densitas, ρ
BM campuran = 2,000 R
= 8,3145
k
=
jam
kg min
kg
= 0,9997
Cp campuran = 28,780
kg
m3 kJ kmol K kg
kmol
kJ kmol K
Cp campuran Cp campuran - R
= 1,406 b.
Kondisi Operasi
Tekanan masuk, Pin
= 18 atm
Tekanan keluar, Pout = 5 atm Temperatur, T
= 155 °C = 428,150 K
Faktor keamanan
= 10%
.... (Mc. Cabe, Hal. 820)
c.
Laju Alir Volumetrik, Q
Q
=
laju alir massa densitas
= 95,186
m3 min
= 312,289 d.
ft3 min
Kapasitas Ekspander
Faktor keamanan
= 10%
Kapasitas ekspander, Q1
= (100% + 10%) × Q = 343,518
e. Pw
min
Daya Ekspander, Pw =
0,0643 k T Q1 520 (k - 1) η
P1
k-1 k
[(P ) 2
- 1] (Mc. Cabe, Pers. 8.30, 2005)
dimana, k
= 1,406
T
= 107,058 °C
Q1
= 343,518
η
= 0,85
P1
= 18 atm
P2
= 5 atm
ft3 min
sehingga, Pw
ft3
=
0,0643 k T Q1 520 (k - 1) η
P1
k-1 k
[(P ) 2
= 33,166 hp = 33 hp
- 1]
IDENTIFIKASI Nama Alat
Ekspander 01
Kode Alat
EP-01
Jumlah
1 buah
Fungsi
Untuk menurunkan tekanan gas Hidrogen yang keluar dari top Flash Drum-01 DATA DESIGN
Tipe
Turbin
Temperature design
155,000
Tekanan design
o
C
18 Atm 343,518 ft3/min
Kapasitas
DATA MEKANIK Temperatur keluar
155,000
o
C
Tekanan masuk
18 Atm
Tekanan keluar
5 Atm
Power Bahan konstruksi
35,000 Hp Carbon Steel
11.
FLASH DRUM - 01 (FD-01) Fungsi
: Untuk memisahkan antara aliran Crude Etanol dengan Hidrogen
Tipe
: Silinder Vertikal dengan Tutup Elipsoidal
Bahan Konstruksi : Carbon steel SA-285, Cr. C Gambar
:
1. Data Desain : Tekanan
: 18 atm
Temperatur
: 155 oC
Laju Alir Uap, WV
: 5709,431 kg/jam
Laju Alir Liquid, WL
: 61095,141 kg/jam
Densitas Uap
: 709,2 kg/m3
Densitas Liquid
: 987,8 kg/m3
2. Vapor volumetric flowrate, QV QV
laju alir massa densitas =
=
5709,431 kg/jam 709,2 kg/m3
= 8,0505228 m3/jam = 0,1341754 m3/min
3. Kecepatan uap maksimum, UV UV
=
L g 0,035 g
𝑘𝑔 𝑚3
987,8
= 0,035 [(
0,5
–709,2
709,2
𝑘𝑔 𝑚3
𝑘𝑔 𝑚3
0,5
)
]
= 0,02194 m/s 4. Vessel area minimum, A
A
Qv = Uv
1,7974 m3 / s = 0,2810 m / s = 6,3970 m2 5. Diameter vessel minimum, D
D
4A =
=(
0,5
4 𝑥 6,3970 𝑚2 3,14
0,5
)
= 2,8547 m 6. Liquid volumetric flowrate, QL QL
laju alir massa densitas =
=
61.095,142 𝑘𝑔/𝑗𝑎𝑚 987,8 𝑘𝑔/𝑗𝑎𝑚
= 61,850 m3/jam = 0,0172 m3/s 7. Tinggi Liquid, HL Holding time, t
= 10 menit
(Walas, Hal. 612)
= 0,1667 jam HL
=
t A
QLx
= 0,0172
𝑚3 𝑗𝑎𝑚
0,1667 𝑗𝑎𝑚
𝑥
6,7281 𝑚2
= 1,6853 m
8. Tinggi vessel, HV Jarak top ke nozzle inlet, Hv
= 4 ft + D
Hal. 461, Coulson
= 1,2192 + 2,9276 m = 4,1470 m 𝐷
Jarak nozzle inlet ke level liquid maksimum, HZ = =
Hal. 461, Coulson
2
2,9276 m 2
= 0,4572 m Ht
= HL + HV + HZ = 1,6853 m + 4,1470 m + 0,4572 m = 6,2893 m
9. Volume vessel, Vt Digunakan vertikal Flash Drum dengan head tipe ellipsoidal head 𝜋
D2 Hs
Volume shell vessel, Vs
=
Tinggi shell, Hs
= 12,304 m
4
Maka : Volume shell vessel , Vs
=
𝜋 4
D2 Hs
= 20,696 m3 Volume head, Vh
=
𝜋 12
D3
= 6,5657 m3 Volume vessel, Vt = 20,696 m3 + (2 x 6,5657 m3) = 33,827 m3 10. Tebal dinding vessel, t
= Vs + 2Vh
Untuk Silinder
:t=
P r C S E - 0,6 P
Untuk Ellipsoidal Head
:t=
P D C 2S E - 0,2 P ( (Peter & Timmerhaus, 1991), Tabel 4)
Dimana : P
= Tekanan design
= 1 atm
D
= Diameter vessel
= 56,1939 in
R
= Jari-Jari vessel
= 28,0969 in
S
= Working stress allowable
=
= Joint effisiensi
= 0,85
= Korosi maksimum
= 0,010 in
= 14,9690 psi
13.700 psi
(Table 4, Peter,
hal538) E
(Table 4, Peter,
hal538) C
(Table 6, Peter, hal542)
Maka : Tebal dinding silinder : t
=
Pr CC S E - 0,6 P
=
(114,6960 psi 28,0969 in) 0,010 in (13.700 psi 0,85) - (0,6 14,6960 psi)
= 0,00785 m Tebal dinding ellipsoidal head : t
=
PD CC 2S E - 0,2 P
=
(14,6960 psi 56,1939 in) 0,010 in (2 13.700 psi 0,85) - (0,2 14,6960 psi)
= 0,0809 in = 0,0021 m 11. Outside diameter, OD
OD
= D + 2t = 2,9276 m + (2 x 0,03408 m) = 2,9957 m
IDENTIFIKASI Nama Alat
Flash Drum-01
Kode Alat
FD-01
Jumlah
1 Unit
Fungsi
Untuk memisahkan gas Hidrogen dari Crude Etanol DATA DESAIN
Tipe
Silinder Vertikal dengan Tutup Elipsoidal
Temperatur
155 oC
Tekanan
18 atm DATA MEKANIK
Laju Alir Uap
8,0505228 kg/jam
Laju Alir Liquid
61,849708 kg/jam
Diameter Vessel
2,9276 m
Tinggi Vessel
6,2893 m
Tebal Dinding
34,0782 mm
Bahan Konstruksi Carbon steel SA-285, Cr. C
12.
HEATER - 01 (H-01) Fungsi
: Memanaskan bahan baku asam asetat dari T-01
Tipe
: Shell and Tube Heat Exchanger
Gambar
:
Aliran inlet Tube
Shell
Rear End
Head
Aliran outlet
Fluida Panas
Water in
: Steam
W
= 33.641,509 kg/hr
= 74.166,745 lb/hr
T1
= 350 oC
= 662oF
T2
= 350 oC
= 662oF
Fluida Dingin
: Output Vaporizer-01 (As. Asetat, Etil Asetat, dan Air)
w
= 85.202,804 kg/hr
= 187.839,805 lb/hr
t1
= 188oC
= 244,580 oF
t2
= 155oC
= 311,000 oF
Perhitungan design sesuai dengan literatur pada buku Donald Q. Kern (1965). 2. Beban Panas H-01A Q
= 30.139.428,492 kJ/hr = 28.567.084,647 Btu/hr
3. LMTD Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
662
Suhu tinggi
311,000
351,000
662
Suhu rendah
244,580
417,420
Selisih
LMTD =
-66,420
t 2 t1 ln (t 2 / t1 )
= 383,251 oF Ft
=1
t
= 383,251 oF
(Fig.18, Kern)
4. Temperatur Rata-rata Tavg =
T1 T 2 2
= 662oF tavg
=
t1 t 2 2
= 277,790 oF 5. Menentukan luas daerah perpindahan panas Asumsi UD = 150 Btu/hr.ft2.oF A
= =
(Tabel 8, Kern)
Q U D . t 30.139.428,492 150 𝑥 383,251
= 496,925 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger 6. Spesifikasi tube dan shell
Tube Side
= Aliran bahan baku asam asetat dari T-01
Panjang tube (L)
= 14 ft
Outside Diameter (OD) = 1,25 in BWG
= 18
Pass
=4
a”
= 0,327 ft2/lin ft A = L x a"
Jumlah tube, Nt
=
496,925 14 𝑥 0,327
= 108,513 Dari tabel.9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt
= 105
Corrected Coefficient, UD A
= Nt x L x a'' = 105 x 14 ft x 0,327 ft2 = 480,837 ft2
UD
=
Q U D . t
= 163,551 karena nilai Ud perhitungan mendekati nilai Ud asumsi, maka data untuk shell : Shell
= steam
ID
= 21,25 inch
(Tabel 9, Kern)
Baffle Space (B = ID/2) = 10,625 inch Pass
=4
Pt
= 1,5625
in triangular pitch
7. Perhitungan desain bagian tube
Flow Area/tube, a’t a’t
= 1,040 in2
(Tabel 10, Kern)
at
=
Nt a ' t 144 n
(Pers. 7.48, Kern)
105 𝑥 1,040
=
144 𝑥 4
= 0,1896 ft2
Laju Alir, Gt Gt
= W/at =
187.839,805 0,1896
= 990.803,369 lb/hr.ft2
Bilangan Reynold, Ret μ
= 0,0083 cp
ID
= 1,150 inch = 0,0958 ft
Ret
= ID.Gt/ μ
= 0,0201 lb/ft hr (Tabel 10, Kern)
= 11.404.274,503
Dengan L/D = 159,652 diperoleh Jh = 1000
(Fig.24, Kern)
Nilai hi CP
= 0,0013 Btu/lb.oF
k
= 0,0109 Btu/hr ft.oF
c. k
= 0,00236
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
= 15,125 Btu/hr ft2 oF
hio
= hi x ID/OD
8. Perhitungan desain bagian shell ID = Diameter dalam shell
= 21,25 in
B = Baffle spacing
= 10,625 in
Pt = tube pitch
= 1,5625 in = Pt – OD = 1,5625 – 1 = 0,3125 in
Flow Area, as as
=1
(Pers. 6.5, Kern)
= 13,915 Btu/hr.ft2.oF
C’ = Clearance
0 ,14
= ID x C’B/144 PT
= =
23,25 0,250 11,625 144 1,25 21,25 x 0,3125 x 10,625 144 𝑥 1,5625
= 0,3136 ft2
Laju Alir, Gs Gs
= w/as =
74.166,745 𝑙𝑏/ℎ𝑟 0,3136 ft2
= 236.512,360 lb/hr.ft2
Bilangan Reynold, Res de
= 0,720 in
(Fiq.28 Kern)
De (Equivalent diameter) = 0,06 ft μ
= 0,022 cp
Res
=
= 0,054 lb/ft hr
GS De
= 577.209,671 Maka: jH
= 500
(Fig.28, Kern)
Nilai ho Cp
= 0,0004 Btu/lb.oF
k
= 0,015 Btu/hr ft.oF
Cp. k
1
3
= 0,0008
Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3 = 9,470 Btu / hr ft2 oF
9. Clean Overall Coefficient, UC UC
=
hio ho hio ho
= 5,635 Btu/hr.ft2.oF 10. Dirt Factor, Rd Rd
=
U C U D U C U D
= 0,1713 hr.ft2.oF/Btu 11. Pressure drop
Bagian tube Untuk NRe
= 11.404.274,503
Faktor friksi
= 0,0001
s
= 5,873
ΔPt
f Gt 2 L n = 5, 22 x 10 10 x De s f t
(Fig 26, Kern)
= 0,047 psi V2 / 2g
= 1,000
ΔPr
= ( 4n/s ) ( V2/2g )
(Fig 27, Kern)
= 2,7244 Psi ΔPT
= ΔPt + ΔPr = 0,047 psi + 2,7244 Psi = 2,7711 psi
Shell Side Re
= 577.209,671
f
= 0,001
N+1
= 12 L / B = 189,741
Ds
= 1,771 ft
s
=1
ΔPs
=
fGs2 Ds ( N 1) 5,22 1010 Desf s
= 4,7481 psi
(Fig.29, Kern)
IDENTIFIKASI Nama Alat
Heater– 01
Kode
H-01
Jumlah
1
Fungsi
Menaikkan suhu bahan baku keluaran Vaporizer
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
5,635
Btu/hr ft2 oF
Ud
163,551
Btu/hr ft2 oF
Rd Calculated
0,171
hr ft2 oF/Btu
TUBE SIDE Length OD
14
Ft
1,250
In
Passes
4
BWG
18
Pitch
1,5625
Nt ΔPT
105 2,771
in Triangular Pitch Tubes Psi
SHELL SIDE ID
21,25
in
B
10,625
in
Passes ΔPs
4 4,748
psi
13.
HEATER - 02 (H-02)
Fungsi
: Menaikkan suhu Feed sebelum masuk R - 01
Tipe
: Double Pipe Heat Exchanger
Gambar
:
Return bend
t1 Gland
Gland
Gland
T2
T1 Tee Return Head
t2
Fluida Panas
:
Saturated steam
Flowrate,
W1 = 12.120,647 Kg/jam
= 26.721,421 lb/hr
T1
= 350 oC
= 662 oF
T2
= 350 oC
= 662 oF
Fluida Dingin
:
Bahan baku untuk masuk reaktor
Flowrate,
W2
= 67.556,947 Kg/jam
= 14214,2607 lb/hr
t1
= 123,757 oC
= 254,763 oF
t2
= 174,171 oC
= 345,508 oF
Perhitungan design sesuai dengan literatur pada Donald Q. Kern (1965). a.
Beban Panas H - 02 Q = 10.858.887,717 kJ/jam = 10.292.390,404 Btu/hr
b.
LMTD Fluida Panas
Fluida Dingin
(oF)
(oF)
Selisih
662 (T1)
Suhu Tinggi (th)
345,508 (t2)
316,492
662 (T2)
Suhu Rendah (tc)
254,763 (t1)
407,237
Selisih
-90,745
t 2 t1 ln T1 / T2
LMTD
∆t = 359,960 oF c.
Temperatur rata-rata Tc
= T avg
= 662,000 oF
tc
= t avg
= 300,135 o F
Penentuan tipe Heater : Asumsi UD = 170 Btu/hr.ft2.F A
Q U D t
A = 168,1948 ft2 Karena A < 200 ft2 , maka dipilih jenis Double Pipe Heat Exchanger Dari Tabel.10 Kern didapat spesifikasi data : Rencana Klasifikasi : Data Pipa
Annulus
Inner Pipe
IPS (in)
12
10
SN
30
40
OD (in)
12,75
10,75
ID (in)
12,09
10,02
a” (ft2/ft)
3,338
2,814
FLUIDA PANAS : Annulus a. Flow Area, aa D2 =
12,09 inch
= 1,0075 ft
D1 =
10,75 inch
= 0,8958 ft
aa =
(D22 – D12) 4
=
0,1668 ft2
Equivalent Diameter De
=
D
2
2
D1 D1
2
= 0,2373 ft b. Kecepatan Massa, Ga Ga
= W/aa = 16.159,0510 lb/hr.ft2
Pada T = 662 oF μ =
0,0432 lb/ft.hr
Rea
= De.Ga/μ = 363.718,389
JH = 700 k
(Fig. 28, Shell-side heat transfer curve)
= 0,0283 Btu/hr.ft2(oF/ft)
CP = 0,0021 Btu/lb.oF c k
c.
1
3
= 0,1991 Koefisien perpindahan panas
ho =
JH
k c De k
1
3
w
0 ,14
= 16,6098 Btu/hr.ft2.oF
FLUIDA DINGIN: Inner Pipe a. Flow Area, ap D =
10,02 inch
ap =
2 D 4
=
(0,835 ft)2 4
= 0,5437 ft2 b. Kecepatan Massa, Gp
= 0,835 ft
Gp
= w/ap = 272120,433 lb/hr.ft2
Pada 300,135 oF µ
= 0,0142 lb/hr ft
Rep
= D.Gp/μ = 6.630.847,0291
JH
= 1000
(Fig. 24, Tube-side heat transfer
curve) k
= 0,0156 Btu/hr.ft2(oF/ft)
c
= 82,6785 Btu/lb.oF
c k
c.
1
3
= 0,1042
Koefisien Perpindahan Panas hi
= JH
k c De k
1
3
w
0 ,14
= 10,645 Btu/hr.ft2.oF Koreksi hi pada permukaan OD hio = hi x ID/OD = 9,922 Btu/jam ft2 oF d. Clean Overall Coefficient, UC UC = =
hio ho hio ho
6,2116 Btu/hr.ft2.oF
e. Design Overall Coefficient, UD 1 1 Rd U D UC
Rd diasumsikan 0,001 UD
= 6,1354 Btu/hr.ft2.oF
f.
Required Surface
A =
Q U D t
= 4.660,3701 ft2 Dari tabel 11 Kern, untuk 10-in IPS standard pipe, external surface/foot length a”= 2,814 ft2. Required length
= 1656,137 ft
Diambil panjang 1 hairpin = 20 ft, maka jumlah hairpin yang dibutuhkan = 42 buah Actually Length
= Jumlah hairpin x panjang hairpin x 2 = 4660,3701 ft
Actually surface
= L x a” = 4660,3701
g. Dirt Factor, Rd UD = = Rd =
Q A t
6,1354 Btu/hr.ft2.oF
U C U D U C U D
= 0,002 hr.ft2.oF/Btu PRESSURE DROP FLUIDA PANAS : Annulus a. De’ = (D2 – D1) = 0,1117 ft Rea ƒ
= 363718,389
= 0,0035
0,264 (Re a' ) 0, 42
= 0,0047 ρ
=
7,083 lb/ft3
b. ΔFa =
4 fGa2 L 2 g 2 De
= 171,2243 Va
=
Ga 3600
= 6,281 ft/s
V 2 = 1 x 2g
d. Fl
= 1,2252 e. ΔPa =
(Fa F1) 144
= 8,4824 Psi
FLUIDA DINGIN : Inner Pipe a. Rep = ƒ
6630847,0291
= 0 , 0035
0 , 264 (Re p ) 0 , 42
= 0,0039 ρ
= 0,3154 lb/ft3
b. ΔFp =
4 fGp 2 L 2 g 2 D
= 2726,9200 ft Fp . c. ΔPp = 144 = 5,9727 Psi
IDENTIFIKASI Nama Alat
Heater – 02
Kode
H-02
Jumlah
1
Fungsi
Untuk memanaskan bahan baku reaktor
Tipe
Double pipe heat exchanger DATA DESAIN Uc
6,2116
Btu/hr ft2 oF
Ud
6,1354
Btu/hr ft2 oF
Rd Calculated
0,002
hr ft2 oF/Btu
ANNULUS IPS
12
Sch. No
30
In
OD
12,75
in
ID
12,09
in
a”
3,338
Ft2
Pa
8,482
Psi
INNER IPS
10
Sch. No
40
In
OD
10,75
in
ID
10,02
in
a”
2,814
Ft2
Pp
5,973
Psi
14.
HEATER - 03 (H-03)
Fungsi
: Menaikkan suhu Feed sebelum masuk R - 01
Tipe
: Double Pipe Heat Exchanger
Gambar
:
Return bend
t1 Gland
Gland
Gland
T2
T1 Tee Return Head
t2
Fluida Panas
:
Saturated steam
Flowrate,
W1 = 12.521,484 Kg/jam
= 27.605,115 lb/hr
T1
= 350 oC
= 662 oF
T2
= 350 oC
= 662 oF
Fluida Dingin
:
Bahan baku untuk masuk reaktor
Flowrate,
W2
= 67.556,947 Kg/jam
= 14214,2607 lb/hr
t1
= 174,171 oC
= 345,508 oF
t2
= 224,586 oC
= 436,253 oF
Perhitungan design sesuai dengan literatur pada Donald Q. Kern (1965). a.
Beban Panas H - 03 Q = 11.217.997 kJ/jam = 10.632.766,243 Btu/hr
b.
LMTD Fluida Panas
Fluida Dingin
(oF)
(oF)
Selisih
662 (T1)
Suhu Tinggi (th)
436,2530 (t2)
225,7470
662 (T2)
Suhu Rendah (tc)
345,5078 (t1)
316,4922
Selisih
-90,7452
t 2 t1 ln T1 / T2
LMTD
∆t = 268,5693 oF c.
Temperatur rata-rata Tc
= T avg
= 662,000 oF
tc
= t avg
= 390,880 o F
Penentuan tipe Heater : Asumsi UD = 199 Btu/hr.ft2.F A
Q U D t
A = 198,947 ft2 Karena A < 200 ft2 , maka dipilih jenis Double Pipe Heat Exchanger Dari Tabel.10 Kern didapat spesifikasi data : Rencana Klasifikasi : Data Pipa
Annulus
Inner Pipe
IPS (in)
14
10
SN
30
40
OD (in)
14
10,75
ID (in)
13,25
10,02
a” (ft2/ft)
3,665
2,814
FLUIDA PANAS : Annulus c. Flow Area, aa D2 =
13,25 inch
= 1,0075 ft
D1 =
10,75 inch
= 0,8958 ft
aa =
(D22 – D12) 4
=
0,3271ft2
Equivalent Diameter
De
=
D
2
2
D1 D1
2
= 0,4651 ft
d. Kecepatan Massa, Ga Ga
= W/aa = 84.397,8044 lb/hr.ft2
Pada T = 662 oF μ =
0,0432 lb/ft.hr
Rea
= De.Ga/μ = 375.746,786
JH = 700 k
(Fig. 28, Shell-side heat transfer curve)
= 0,0283 Btu/hr.ft2(oF/ft)
CP = 0,0021 Btu/lb.oF c k
c.
1
3
= 0,1991 Koefisien perpindahan panas
ho =
JH
k c De k
1
3
w
0 ,14
= 8,4725 Btu/hr.ft2.oF FLUIDA DINGIN: Inner Pipe b. Flow Area, ap D =
10,02 inch
ap =
2 D 4
=
(0,835 ft)2 4
= 0,5437 ft2 b. Kecepatan Massa, Gp Gp
= w/ap
= 0,835 ft
= 272120,433 lb/hr.ft2
Pada 300,135 oF µ
= 0,0142 lb/hr ft
Rep
= D.Gp/μ = 6.034.241,255
JH
= 1000
(Fig. 24, Tube-side heat transfer
curve) k
= 0,0938Btu/hr.ft2(oF/ft)
c
= 0,0029 Btu/lb.oF
c k
c.
1
3
= 0,1055
Koefisien Perpindahan Panas hi
= JH
k c De k
1
3
w
0 ,14
= 11,8593 Btu/hr.ft2.oF Koreksi hi pada permukaan OD hio = hi x ID/OD = 11,0540 Btu/jam ft2 oF d. Clean Overall Coefficient, UC UC = =
hio ho hio ho
4,7963 Btu/hr.ft2.oF
e. Design Overall Coefficient, UD 1 1 Rd U D UC
Rd diasumsikan 0,002 UD
= 4,7507 Btu/hr.ft2.oF
f.
Required Surface
A =
Q U D t
= 8333,5353 ft2 Dari tabel 11 Kern, untuk 10-in IPS standard pipe, external surface/foot length a”= 2,814 ft2. Required length
= 1656,137 ft
Diambil panjang 1 hairpin = 20 ft, maka jumlah hairpin yang dibutuhkan = 42 buah Actually Length
= Jumlah hairpin x panjang hairpin x 2 = 2961,4553 ft
Actually surface
= L x a” = 2961,4553
g. Dirt Factor, Rd UD = = Rd =
Q A t
4,7505 Btu/hr.ft2.oF
U C U D U C U D
= 0,002 hr.ft2.oF/Btu
PRESSURE DROP FLUIDA PANAS : Annulus a. De’ = (D2 – D1) = 0,2083 ft Rea ƒ
= 375.746,7858
= 0,0035
0,264 (Re a' ) 0, 42
= 0,0047 ρ
=
7,083 lb/ft3
d. ΔFa =
4 fGa2 L 2 g 2 De
= 45,4122 ft
Va
=
Ga 3600
= 3,3099 ft/s
V 2 = 1 x 2g
d. Fl
= 0,3402 e. ΔPa =
(Fa F1) 144
= 2,2504 Psi
FLUIDA DINGIN : Inner Pipe a. Rep = ƒ
663421,2553
= 0 , 0035
0 , 264 (Re p ) 0 , 42
= 0,0039 ρ
= 0,8803 lb/ft3
b. ΔFp =
4 fGp 2 L 2 g 2 D
= 628,3145 ft Fp . c. ΔPp = 144 = 3,841 Psi
IDENTIFIKASI Nama Alat
Heater – 03
Kode
H-03
Jumlah
1
Fungsi
Untuk memanaskan bahan baku reaktor
Tipe
Double pipe heat exchanger DATA DESAIN Uc
4,796
Btu/hr ft2 oF
Ud
4,750
Btu/hr ft2 oF
Rd Calculated
0,002
hr ft2 oF/Btu
ANNULUS IPS
14
Sch. No
30
In
OD
14,00
in
ID
13,25
in
a”
3,665
Ft2
Pa
2,250
Psi
INNER IPS
10
Sch. No
40
In
OD
10,75
in
ID
10,02
in
a”
2,814
Ft2
Pp
3,841
Psi
15.
HEATER- 04 (H-04) Fungsi
: Memanaskan bahan baku sebelum masuk R-01
Tipe
: Shell and Tube Heat Exchanger
Gambar
:
Aliran inlet Tube
Shell
Rear End
Head
Aliran outlet
Fluida Panas
Water in
: Steam
W
= 33.641,509 kg/hr
= 74.166,745 lb/hr
T1
= 350 oC
= 662oF
T2
= 350 oC
= 662oF
Fluida Dingin
: Output Vaporizer-01 (As. Asetat, Etil Asetat, dan Air)
w
= 85.202,804 kg/hr
= 187.839,805 lb/hr
t1
= 188oC
= 244,580 oF
t2
= 155oC
= 311,000 oF
Perhitungan design sesuai dengan literatur pada buku Donald Q. Kern (1965). 12. Beban Panas H-01A Q
= 30.139.428,492 kJ/hr = 28.567.084,647 Btu/hr
13. LMTD Fluida Panas (oF) 662
Suhu tinggi
Fluida Dingin (oF)
Selisih
311,000
351,000
662
Suhu rendah
244,580
Selisih
LMTD =
417,420 -66,420
t 2 t1 ln (t 2 / t1 )
= 383,251 oF Ft
=1
t
= 383,251 oF
(Fig.18, Kern)
14. Temperatur Rata-rata Tavg =
T1 T 2 2
= 662oF tavg
=
t1 t 2 2
= 277,790 oF 15. Menentukan luas daerah perpindahan panas Asumsi UD = 150 Btu/hr.ft2.oF A
= =
(Tabel 8, Kern)
Q U D . t 30.139.428,492 150 𝑥 383,251
= 496,925 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger 16. Spesifikasi tube dan shell
Tube Side
= Aliran bahan baku asam asetat dari T-01
Panjang tube (L)
= 14 ft
Outside Diameter (OD) = 1,25 in BWG
= 18
Pass
=4
a”
= 0,327 ft2/lin ft A L x a"
Jumlah tube, Nt
= =
496,925 14 𝑥 0,327
= 108,513 Dari tabel.9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt
= 105
Corrected Coefficient, UD A
= Nt x L x a'' = 105 x 14 ft x 0,327 ft2 = 480,837 ft2
UD
=
Q U D . t
= 163,551 karena nilai Ud perhitungan mendekati nilai Ud asumsi, maka data untuk shell : Shell
= steam
ID
= 21,25 inch
(Tabel 9, Kern)
Baffle Space (B = ID/2) = 10,625 inch Pass
=4
Pt
= 1,5625
in triangular pitch
17. Perhitungan desain bagian tube
Flow Area/tube, a’t a’t
= 1,040 in2
(Tabel 10, Kern)
at
=
Nt a ' t 144 n
(Pers. 7.48, Kern)
105 𝑥 1,040
=
144 𝑥 4
= 0,1896 ft2
Laju Alir, Gt Gt
= W/at
=
187.839,805 0,1896
= 990.803,369 lb/hr.ft2
Bilangan Reynold, Ret μ
= 0,0083 cp
ID
= 1,150 inch = 0,0958 ft
Ret
= ID.Gt/ μ
= 0,0201 lb/ft hr (Tabel 10, Kern)
= 11.404.274,503
Dengan L/D = 159,652 diperoleh Jh = 1000
(Fig.24, Kern)
Nilai hi CP
= 0,0013 Btu/lb.oF
k
= 0,0109 Btu/hr ft.oF
c. k
= 0,00236
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
= 15,125 Btu/hr ft2 oF
hio
= hi x ID/OD
=1
(Pers. 6.5, Kern)
= 13,915 Btu/hr.ft2.oF 18. Perhitungan desain bagian shell ID = Diameter dalam shell
= 21,25 in
B = Baffle spacing
= 10,625 in
Pt = tube pitch
= 1,5625 in
C’ = Clearance
0 ,14
= Pt – OD = 1,5625 – 1 = 0,3125 in
Flow Area, as = ID x C’B/144 PT
as
= =
23,25 0,250 11,625 144 1,25 21,25 x 0,3125 x 10,625 144 𝑥 1,5625
= 0,3136 ft2
Laju Alir, Gs Gs
= w/as =
74.166,745 𝑙𝑏/ℎ𝑟 0,3136 ft2
= 236.512,360 lb/hr.ft2
Bilangan Reynold, Res de
= 0,720 in
(Fiq.28 Kern)
De (Equivalent diameter) = 0,06 ft μ
= 0,022 cp
Res
=
= 0,054 lb/ft hr
GS De
= 577.209,671 Maka: jH
= 500
(Fig.28, Kern)
Nilai ho Cp
= 0,0004 Btu/lb.oF
k
= 0,015 Btu/hr ft.oF
Cp. k
1
3
= 0,0008
Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3\
= 9,470 Btu / hr ft2 oF
19. Clean Overall Coefficient, UC UC
=
hio ho hio ho
= 5,635 Btu/hr.ft2.oF 20. Dirt Factor, Rd Rd
=
U C U D U C U D
= 0,1713 hr.ft2.oF/Btu 21. Pressure drop
Bagian tube Untuk NRe
= 11.404.274,503
Faktor friksi
= 0,0001
s
= 5,873
ΔPt
=
(Fig 26, Kern)
f Gt 2 L n 5, 22 x 10 10 x De s f t
= 0,047 psi V2 / 2g
= 1,000
ΔPr
= ( 4n/s ) ( V2/2g )
(Fig 27, Kern)
= 2,7244 Psi ΔPT
= ΔPt + ΔPr = 0,047 psi + 2,7244 Psi = 2,7711 psi
Shell Side Re
= 577.209,671
f
= 0,001
N+1
= 12 L / B
(Fig.29, Kern)
= 189,741 Ds
= 1,771 ft
s
=1
ΔPs
fGs2 Ds ( N 1) = 5,22 1010 Desf s = 4,7481 psi
IDENTIFIKASI Nama Alat
Heater– 04
Kode
H-04
Jumlah
1
Fungsi
Menaikkan suhu bahan baku keluaran Vaporizer
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
9,761
Btu/hr ft2 oF
Ud
155,760
Btu/hr ft2 oF
Rd Calculated
0,096
hr ft2 oF/Btu
TUBE SIDE Length OD
14
Ft
1,500
In
Passes
1
BWG
18
Pitch
1,875
Nt ΔPT
76 3,138
in Triangular Pitch Tubes Psi
SHELL SIDE ID
21,25
in
B
10,625
in
Passes
1
ΔPs
16.
A.
1,037
psi
KOLOM DESTILASI - 01 (KD-01)
Fungsi
: Memisahkan Etanol dan Air
Tipe
: Sieve Tray Tower
Material
: Carbon Steel
Gambar
:
Menentukan kondisi operasi.
Feed P = 1 atm
= 760,000 mmHg
T = 82,767 oC
= 355,917 K
Komponen
Pi
Xi=Yi/Ki
Ki = Pi / P
Yi=Xi . Ki
asam asetat
230.462
0.052
0.303
0.016
air
397.047
0.257
0.522
0.134
etanol
903.672
0.519
1.189
0.617
etil acetate
908.285
0.060
1.195
0.072
Total
2,439.466
0.887
3.210
1.000
Top P = 0,6 atm
= 456,000 mmHg
T = 67,096 oC
= 340,246 K
Komponen
Kmol
Yi
Ki = Pi / P
Xi = Yi / Ki
asam asetat
0.009
0.000
0.270
0.000
air
35.954
0.038
0.452
0.084
etanol
913.022
0.959
1.050
0.913
etil acetate
3.233
0.003
1.188
0.003
Total
952.217
1.000
2.959
1.000
Bottom P = 1 atm
= 760,000 mmHg
T = 98,787 oC
= 371,971 K
Komponen
Kmol
Yi
Ki = Pi / P
Xi = Xi*Ki
asam asetat
14.505
0.016
0.540
0.009
air
862.884
0.942
0.957
0.902
etanol
38.043
0.042
2.139
0.089
etil acetate
0.129
0.000
1.922
0.000
Total
915.562
1.000
5.559
1.000
B. Desain Kolom Destilasi a. Menentukan Relatif Volatilitas, α Komponen kunci : Light Key
: Etanol
Heavy Key
: Air
αD
K LK K HK
= KLK / KHK = 1,050 / 0,452 = 2,324
αB
= KLK / KHK = 2,139 / 0,957 = 2.234
Avg
Top
x Bot
2,324 x 2,234
=
= 2,279 b. Menentukan Stage Minimum Dengan menggunakan metode Fenske ( R. Van Winkle;eg : 5.118 ; p 236)
SM
Log X LK / X HK D x X HK / X LK B Log ( Avg )
SM
Log 25,395D x 22,682B Log (3.118)
NM = 7.717 c. Menentukan rasio refluks minimum, Rmin n
1 – q = 1
xF ( ) / n
(L/D)min + 1 =
q=1
xD
( ) / 1
Komponen
Xf
Α
(α-θ)/α
Xf/(α-θ)/α
XD/(α-θ)/α
asam asetat
0.014
0.580
-1.031
-0.014
0.000
air
0.265
1.000
-0.179
-1.482
-0.211
etanol
0.716
2.276
0.482
1.485
1.989
etil acetate
0.005
2.288
0.485
0.010
0.007
Total
1.000
0.000
0.000
1.784
(L/D)m = 1,784 – 1 = 0,784
(L/D) = 1,5 x (L/D)m = 1,5 x 0,784 = 1.177 d. Teoritical Tray Pada Actual reflux – Methode Gilliland Diketahui
: Rm
= 0,784
Nm
= 7.717
L / D ( L / D) m 1,177 0,784 L/ D 1 1,177 1 = 0,466 Dari grafik 5.18 hal hal.243 Van Winkle (Gilland Corelation) diperoleh :
N Nm = 0,466 N 1 N
= 17,823 stage ~ 18 stage
R akt
= 1,177
N teori
= 17,823
e. Menentukan Feed Location. Feed location ditentukan dengan menggunakan metode Kirkbride: m
B X X 2 0,206 Log HK LK B dengan: D X LK F X HK D B = molar flow pada bagian bawah produk
Log
D
p
=
= molar flow pada bagian atas produk
(XHK)f = konsentrasi heavy key pada feed (XLK)f = konsentrasi light key pada feed (XHK)d = konsentrasi heavy key pada bagian atas produk (XlK)b = konsentrasi light key pada bagian bawah produk
18,163.581 0,495 1.211 0,206 Log 42,931.198
Log
m
=
p
Log
m p
m
= -0,596 = 0,754 p
Ntheoritical
= m + p
17,823
= 0,754 p + p
17,823
= 0,754 p
p
= 10,163
m
= 7,660
sehingga: m (rectifying section)
= 7,660 tray = 8 tray
p (stripping section)
= 10,163 tray = 10 tray
berdasarkan dari nilai m dan p, dapat ditentukan bahwa feed yang masuk pada tray ke 19 dari bagian atas kolom destilasi. C. Desain kolom bagian atas (Rectifying section) a. Data fisik untuk rectifying section D
= 42,931.198 kg/jam
L
=R.D = 1,177 x (42,931.198 kg/jam) = 50,517.531kg/jam = 14,033 kg/det
V
=L+D = 50,517.531 kg/jam + 42,931.198 kg/jam = 93,448.729 kg/jam = 25.958 kg/det Data Fisik
Vapour
Liquid
Mass Flow rate (kg/det)
25.998
14.033
Density (kg/m3)
4.010
733.744
Volumetric Flow rate (m3/det)
6.474
0.019
Surface tension (N/m)
16.751
b. Diameter kolom Liquid – Vapour Flow Factor (FLV)
LW VW
V L
FLV
=
FLV
= 0,541 x 0,074 = 0,040
Ditentukan tray spacing = 0,5 m Dari figure 11.27 buku Chemical Engineering, vol. 6, . JM. Couldson didapat nilai konstanta K1 = 0,094 Kecepatan Flooding (uf) = K1 *
uf
= 0,094
L V V 733,744 4,010 4,010
= 4,873 m/s
Desain untuk 85 % flooding pada maksimum flowrate ( u )
u
= 0,85 . uf = 0,85 . 4,873 m/s = 4,142 m/s
Maksimum volumetric flow rate (Uv maks)
Uv maks
=
V
V
=
93,448.729kg / s 4,010kg / m 3
= 16,385 m3/s Net area yang dibutuhkan (An) An
=
U V maks
u =
16,385 m 3 / s 7,298 m / s
= 6,474 m2
Cross section area dengan 12 % downcormer area (Ac) Ac
=
An 1 0,12
=
6,474m 2 1 0,12
= 1,776 m2 Diameter kolom (Dc) Dc
=
4 Ac 3,14
=
4 . (1,776m 2 ) 3,14
= 1,504 m c. Desain plate Diameter kolom (Dc) Luas area kolom (Ac) Ac
=
Dc 2 . 3,14 4
= 1,504 m
=
(1,504) 2 . 3,14 4
= 1.776 m2 Downcomer area (Ad) Ad
= Persen downcomer x Ac = 0,12 x 1.776 m2
= 0.213 m2 Net area (An) An
= Ac – Ad = 1,776 m2 – 0.213 m2 = 1,563 m2
Active area (Aa) Aa
= Ac – 2 Ad = 1,776 m2 – (2 x 0.213 m2) = 1,350 m2
Hole area (Ah) ditetapkan 10% dari Aa sebagai trial pertama Ah
= 10% . Aa = 0,135 m2
Nilai weir length (lw) ditentukan dari figure 11.31, JM. Couldson ed 6
0,213 x 100 1,776
Ordinat
=
Ad x 100 Ac
=
Absisca
=
Iw Dc
= 0,760
= 12
Sehingga : lw
= Dc . 0,760 = 1,504 m . 0,760 = 1,143 m
Penentuan nilai weir height (hw) , hole diameter (dh), dan plate thickness, (nilai ini sama untuk kolom bagian atas dan bawah) Weir height (hw)
= 50 mm
Hole diameter (dh)
= 5 mm
Plate thickness
= 5 mm
d. Pengecekan Check weeping Maximum liquid rate (Lm,max) Lm,max
= =
L 3600
50,517.531 kg / jam 3600
= 14,033 kg/det Minimum liqiud rate (Lm,min) Minimum liquid rate pada 70 % liquid turn down ratio Lm,min
= 0,7 Lm, max = 0,7 (14,033 kg/det) = 9,823 kg/det
Weir liquid crest (how) 2
how
Lm = 750 l Iw
how,maks
Lm, maks = 750 l Iw
3
(J.M.Couldson. Eq.11.85) 2
3
14,033 kg / det = 750 3 733,744kg / m x 1,143m = 37,614 mm liquid how,min
Lm, min = 750 l Iw
2
3
9,823kg / det = 750 3 733,744kg / m x 1,143m = 28.231 mm liquid Pada rate minimum hw + how
= 50 mm + 28.231 mm
2
3
= 78.231 mm Dari figure 11.30 JM. Coulson ed 6 K2
= 30,9
Minimum design vapour velocity (ŭh) ŭh
=
=
K 2 0,90 25,4 d h 1 V 2 30,9 0,90 25,4 5 1,9941 / 2
= 0,285 m/s Actual minimum vapour velocity (Uv,min actual) Uv,min actual
=
minimum vapour rate Ah
=
70% x 6,474 m 3 /s 0,135 m 2
= 3,357 m/s Nilai ini dapat diterima, karena minimum operating rate harus berada diatas nilai weep point. Plate pressure drop Jumlah maksimum vapour yang melewati holes (Ǚh) Ǚh
=
Uv, maks Ah
6,474 m 3 / s = 0,135 m 2 = 3,357 m/s Dari figure 11.34 JM. Couldson ed 6, untuk : Plate thickness hole diameter
= 1
Ah Ah = Aa Ap
= 0,1
Ah x 100 Ap
= 10,0
Didapat nilai Orifice coeficient (Co) = 0,750 Dry plate drop (hd) 2
hd
Uh = 51 V Co L = 5120,034x0,005 = 15,583 mm liquid
Residual head (hr) hr
=
=
12,5 .10 3
L 12,5 .10 3 733,744kg / m 3
= 17,036 mm liqiud Total pressure drop (ht) ht
= hd + (hw + how) + hr = 15,583 + (78,231) + 17,036 = 110,850 mm liquid
Nilai ht yang didapat tidak jauh berbeda dari 100 mm air yang merupakan basis asumsi pressure drop. Downcomer liquid backup Downcomer pressure loss (hap) hap
= hw – (10 mm) = 50 – 10 = 40 mm
Area under apron (Aap) Aap
= hap . lw = 40 x 10-3 . 1,143 m = 0,046 m2
Karena nilai Aap lebih kecil dari nilai Ad (0,213 m2), maka nilai Aap yang digunakan pada perhitungan head loss di downcomer (hdc) Head loss in the downcomer (hdc) hdc
Lm, max = 166 L Aap
2
13,680 kg/s = 166 3 733,744kg / m 0,046
2
= 0,00012 mm Back up di downcomer (hb) hb
= (hw+ how) + ht + hdc = (78,231) + 110,850 + 0,00012 = 189,081 mm = 0,189 m
(plate spacing + weir height)/2 = 0,275 m hb harus lebih kecil dari (plate spacing + weir height)/2, Ketentuan bahwa nilai hb harus lebih kecil dari (plate spacing + weir height)/2, telah terpenuhi. (J.M.Coulson..p.474) Check resident time (tr) tr
=
=
Ad hbc L Lm, maks
0,213 m 2 . 0,189m .733,744kg / m 3 14,033kg / s
= 2.107 s Check Entrainment Persen flooding actual. uv
=
Uv maks An
6,474m 3 / s = 1,563 m 2
= 4,162 m/s % flooding =
=
uv x100 uf
4,142m / s x100% 4,873 m/s
= 85 % Untuk nilai FLV = 0,040 dari figure 11.29 JM. Couldson ed 6 Didapat nilai ψ = 0,060 Ketentuan bahwa nilai ψ harus lebih kecil dari 1, telah terpenuhi. e. Trial plate layout Digunakan plate type cartridge, dengan 50 mm unperforted strip mengelilingi pinggir plate dan 50 mm wide calming zones.
Dari figure 11.32 JM. Couldson ed 6 pada
1,143m lw = = 0,760 Dc 1,504m
Di dapat nilai θC = 100O Sudut subtended antara pinggir plate dengan unperforated strip (θ) θ
= 180 - θC = 180 – 100 = 80O
Mean length, unperforated edge strips (Lm) Lm
= Dc hw x 3,14 180
80 = 1,504m 0,050m x 3,14 180
= 2,029 m Area of unperforated edge strip (Aup) Aup
= hw . Lm = 0,050 m . 2,029 m = 0,101 m2
Mean length of calming zone (Lcz) Lcz
= ( Dc hw) sin C 2 96 = (1,504 m 0,050 m) sin 2
= 1,081 m Area of calming zone (Acz) Acz
= 2 ( Lcz . hw) = 2 (1,081 m . 0,050m) = 0,108 m2
Total area perforated (Ap) Ap
= Aa – (Aup + Acz) = 1,350 m2 – (0,101 + 0,108) m2 = 1,140 m2
Dari figure 11.33 JM. Couldson ed 6 di dapat nilai Ip/dh = 2,75 untuk nilai Ah/Ap = 0,115 . Nilai Ip/dh = 2,750, harus berada dalam range 2,5 – 4.0 . Jumlah holes Area untuk 1 hole (Aoh) Aoh
dh 2 = 3,14 4 (5 x10 3 m) 2 = 3,14 4 = 0,00001963 m2
Jumlah holes =
Ah Aoh
0,135m 2 = 0,00001963m 2 = 6.878,814 holes = 6.879 holes
f. Ketebalan kolom bagian atas. Ketebalan dinding bagian head, thead t=
P.Da Cc 2.S.E j 0,2.P
( Peter Tabel.4 Hal 537)
Ketebalan dinding bagian silinder, tsilinder t=
P.ri Cc S .E j 0,6.P
( Peter Tabel.4 Hal 537)
Keterangan : P = Tekanan Desain
= 0,6 atm
Da = Diameter Kolom
= 1,504 m
ri = Jari-jari Kolom
= 0,752 m
S = Tekanan kerja yang diperbolehkan = 932,226 atm Cc = Korosi maksimum
= 0,003 m
Ej = Efisien pengelasan
= 0,85
thead
=
0,6atm x 1,504 m 0,003 m 2.(932,226 atm x 0,85) 0,2 x 0,6 atm
= 0,004 m tsilinder =
= 0,358 cm
0,6atm x 0,752m 0,003 m (932,226 atm x 0,85) 0,6 x 0,6 atm
= 0,004 m = 0,358 cm Sehingga : OD = ID + 2tsilinder
= 1,504 m + 2 (0,004 m) = 1,511 m
D. Desain kolom bagian bawah (Striping section) a. Data fisik untuk stripping section F
= 41.119,744 kg/jam
L
= 18.163,581 kg/jam
V
= 41.119,789 kg/jam
q
= 1
q
=
V’
= V ( q 1) F
L’
= F + L
L ' L F
(RE.Treyball, Eq.9.126) (RE.Treyball, Eq.9.127)
= 41.119,744 kg/jam + 18.163,581 kg/jam = 59.283,325 kg/jam = 16,468 kg/det V’
= V = 41.119,789 kg/jam = 11,422 kg/det
Data Fisik
Vapour
Liquid
Mass Flow rate (kg/det)
11,422
16,468
Density (kg/m3)
2,201
926,494
Volumetric Flow rate (m3/det)
5,190
0,018
b. Diameter kolom Liquid –Vapour Flow Factor (FLV)
V L
FLV
=
LW VW
FLV
=
59.283,325 kg / jam 2,201kg / m 3 41.119,789 kg / jam 926,494 kg/ m 3
= 0,048 Ditentukan tray spacing = 0,5 m Dari figure 11.27 buku Chemical Engineering, vol. 6, . JM. Couldson didapat nilai konstanta K1 = 0,082 Kecepatan Flooding (uf)
L V V
= K1
uf
= 0,360
926,494 kg / m 3 2,201kg / m 3 2,201kg / m 3
= 7,370 m/s
Desain untuk 85% flooding pada maksimum flow rate ( u )
u
= 0,85 . uf = 0,85 . 7.370 m/s = 6,264 m/s
Maksimum volumetric flow rate (Uv maks) Uv maks
=
V V . 3600
=
41.119,789 kg / jam 2,201kg / m 3 . 3600
= 5,190 m3/s Net area yang dibutuhkan (An) An
=
U V maks
u 5,190 m 3 / s = 6,264 m / s
= 0,828 m2 Cross section area dengan 12 % downcomer area (Ac) Ac
=
An 1 0,2
0,828 m 2 = 1 0,12 = 0,941 m2 Diameter kolom (Dc) Dc
=
4 Ac 3,14
=
4 (0,941 m 2 ) 3,14
= 1,095 m c. Desain plate Diameter kolom (Dc)
= 1,095 m
Luas area kolom (Ac) Ac
=
Dc 2 . 3,14 4
=
(1,095 m) 2 . 3,14 4
= 0,941 m2 Downcomer area (Ad) Ad
= persen downcomer x Ac = 0,12 (0,941 m2) = 0,113 m2
Net area (An) An
= Ac – Ad = 0.941 m2– 0,113 m2 = 0,828 m2
Active area (Aa) Aa
= Ac – 2 Ad = 0,941 m2 – 2 (0,113 m2) = 0,715 m2
Hole area (Ah) ditetapkan 10% dari Aa sebagai trial pertama Ah
= 10 % . Aa = 10% . 0,715 m2 = 0,072
Nilai weir length (lw) ditentukan dari figure 11.31, JM. Couldson ed 6
0,113 x 100 0,941
Ordinat
=
Ad x 100 Ac
=
Absisca
=
Iw Dc
= 0,760
= 12.000
Sehingga : lw
= Dc . 0,76 = 1,095 m . 0,76 = 1,795 m
Penentuan nilai weir height (hw) , hole diameter (dh), dan plate thickness, (nilai ini sama untuk kolom atas dan kolom bawah) Weir height (hw)
= 50 mm
((J M.Couldson. p.571)
Hole diameter (dh)
= 5 mm
((J M.Couldson. p.573)
Plate thickness
= 5 mm
((J M.Couldson. p.573)
d. Pengecekan Check weeping Maximum liquid rate (Lm,max) Lm,max
=
L 3600
=
59.283,325 kg/jam = 16,468 kg/s 3600
Minimum liqiud rate (Lm,min) Minimum liquid rate pada 70 % liquid turn down ratio
Lm,min
= 0,7 Lm, max = 0,7 (16,468 kg/s) = 11,527 kg/s
Weir liquid crest (how) 2
how
Lm = 750 l Iw
how,maks
Lm, maks = 750 l Iw
3
2
3
16,468 kg / s = 750 3 926,494kg / m . 0,832m
2
3
= 5,773 mm liquid how,min
Lm, min = 750 l Iw
2
3
11,527 kg / s = 750 3 926,494 kg / m . 0,832m
2
3
= 4,551 mm liquid
Pada rate minimum hw + how
= 50 mm + 4,551 mm = 54,551 mm
Dari figure 11.30 JM. Couldson ed 6, diperoleh K2 = 31,00 Minimum design vapour velocity (ŭh) Ŭh
=
=
K 2 0,90 25,4 dh 1 V 2 31 0,90 25,4 5 1,629
1
2
= 0,349 m/s Actual minimum vapour velocity (Uv,min actual)
Uv,min actual
=
minimum vapour rate Ah
70% x 5,190 m 3 /s = 0,072m 2 = 5,078 m/s Jadi minimum operating rate berada diatas nilai weep point.
Plate pressure drop Jumlah maksimum vapour yang melewati holes (Ǚh) Ǚh
=
Uv, maks Ah
=
16,834 m 3 /s 0,333m 2
= 50,575 m/s Dari figure 11.34 JM. Couldson ed 6, untuk : Plate thicness hole diameter
= 1
Ah Ah = Aa Ap
= 0,1
Ah x 100 Ap
= 10
Sehingga didapat nilai Orifice coeficient (Co) = 0,845 Dry plate drop (hd) 2
hd
Uh = 51 V Co L 2
5,078 m/s 2,201kg / m 3 = 51 3 0,845 926,494 kg / m = 3,964 mm liquid
Residual head (hr) hr
=
hr
=
12,5 .10 3
L 12,5 .10 3 1.233,024kg / m 3
= 10,138 mm liqiud Total pressure drop (ht) ht
= hd + (hw + how) + hr = 3,964 mm+ 54,551mm + 10,138 mm = 68,653 mm liquid
Selisih nilai total pressure drop harus lebih besar dari 100 mm liquid, maka desain dapat diterima. (Coulson p.474)
Downcomer liquid backup Downcomer pressure loss (hap) hap
= hw – 10 mm = 50 – 10 = 40 mm
Area under apron (Aap) Aap
= hap . lw = 40 x 10-3m . 0,832 m = 0,05 m2
Karena nilai Aap lebih kecil dari nilai Ad, maka nilai Aap yang digunakan pada perhitungan head loss di downcomer (hdc) Head loss in the downcomer (hdc) hdc
Lm, max = 166 L Aap
2
16,468 kg/s = 166 3 2 926,494kg / m . 0,832m
2
= 0,00013 mm Back up di downcomer (hb) hb
= (hw + how) + ht + hdc = 54,551 mm+ 68,653 mm+ 0,00013 mm = 123,204 mm = 0,123 m
(plate spacing + weir height)/2 = 0,275 m. hb harus lebih kecil dari (plate spacing + weir height)/2 Ketentuan bahwa nilai hb harus lebih kecil dari (plate spacing + weir height)/2, telah terpenuhi.
Check resident time (tr) tr
=
=
Ad hbc L Lm, maks
0,113 m 2 . 0,123m .926,494kg / m 3 16,468 kg / s
= 0,783 s Ketentuan bahwa nilai tr harus lebih besar dari 3 s, telah terpenuhi Check Entrainment Persen flooding actual. uv
=
Uv maks An
5,190 m 3 / s = 0,828 m 2 = 6,264 m/s % flooding =
=
uv x 100 uf
6,264m/s x 100 7,370 m/s
= 85
Untuk nilai FLV = 0,048 dari figure 11.29 Didapat nilai ψ = 0,8 00 Ketentuan bahwa nilai ψ harus lebih kecil dari 1 telah terpenuhi.
e. Trial plate layout Digunakan plate type cartridge, dengan 50 mm unperforted strip mengelilingi pinggir plate dan 50 mm wide calming zones.
Dari figure 11.32 JM. Couldson ed 6 pada
Iw = 0,760 Dc
Di dapat nilai θC = 100OC Sudut subtended antara pinggir plate dengan unperforated strip (θ) θ
= 180 - θC = 180 – 100 = 80OC
Mean length, unperforated edge strips (Lm) Lm
= Dc hw x 3,14 180
80 = 1,095 m 50 x 10 3 m x 3,14 180
= 1,458 m Area of unperforated edge strip (Aup) Aup
= hw . Lm = 50 x 10-3 m . 1,458 m = 0,073 m2
Mean length of calming zone (Lcz) Lcz
= ( Dc hw) sin C 2 96 = (1,095m 50 x 10 3 m) sin 2
= 0,776 m Area of calming zone (Acz) Acz
= 2 ( Lcz . hw) = 2 ( 0,776 m . 50 .10-3m) = 0,078 m2
Total area perforated (Ap) Ap
= Aa – (Aup + Acz) 0,715 m2– (0,073 + 0,078) m2 = 0,565 m2
Dari figure 11.33 JM. Couldson ed 6 di dapat nilai Ip/dh = 2,75 untuk nilai Ah/Ap = 0,127 Nilai Ip/dh = 2,750, harus berada dalam range 2,5 – 4.0 . Jumlah holes Area untuk 1 hole (Aoh) Aoh
= 3,14
dh 2 4
= 3,14
(5 x10 3 m 2 4
= 0,00001963 m2
Jumlah holes =
Ah Aoh
0,072m 2 = 0,00001963m 2 = 3.645,577 holes = 3.645,000 holes f. Ketebalan minimum kolom bagian bawah. Ketebalan dinding bagian head, thead t=
P.Da Cc 2.S.E j 0,2.P
( Peter Tabel.4 Hal 537)
Ketebalan dinding bagian silinder, tsilinder t=
P.ri Cc S .E j 0,6.P
( Peter Tabel.4 Hal 537)
Dimana : P = Tekanan Design
= 1 atm
Da = Diameter Kolom
= 1,095 m
ri = Jari-jari Kolom
= 0,548 m
S = Tekanan kerja maksimum
= 932,226 atm
Cc = Korosi maksimum
= 0,003 m
Ej = Efisien pengelasan
= 0,850
thead
=
1atm x 1,095 m 0,003 m 2.(932,226 atm x 0,850) 0,2 x 1 atm
= 0,004m = 0,4 cm tsilinder =
1atm x 0,548m 0,003 m (932,226 atm x 0,85) 0,6 x 1atm
= 0,004 m = 0,4 cm Sehingga : OD = ID + 2tsilinder = 1,095 m + 2 (0,004m)
= 1,102 m
E. Total Pressure Drop Pressure drop per plate
Rectifying Section
= 110,850 mm liquid = 110,850 mm x10-3 m x 9,8 m/s2x 994,9345 kg/m3 = 1.080,830 Pa
Stripping Section
= 68,653 mm liquid = 68,653 mm x 10-3 m x 9,8 m/s2 x 994,9345 kg/m3 = 669,338 Pa
Total Pressure Drop
= (N1 x P1) + (N2 x P2) = (1.080,830 Pa x 8000) + (669,338 Pa x 10.000) = 15.340,521 Pa = 0,151 atm
F. Tinggi Kolom Destilasi H
= [(N1+1)Tray spacing1 + (N2+1)Tray spacing2] = [(18,741 . 0,5) + (4,024 . 0,5)] = 11,500 m
Heatas = tinggi tutup ellipsoidal atas = ¼ x ID = ¼ x 1,803m = 0,451 m
Hebawah= tinggi tutup ellipsoidal bawah = ¼ x ID = ¼ x 2,362 m = 0,591 m
Ht
= H + Heatas + Hebawah
= 11,500 m + 0,451 m + 0,591 m = 12,541 m
Nama Alat Alat Kode Jenis Jumlah Operasi Fungsi
Tekanan Temperatur
IDENTIFIKASI Kolom Destilasi KD-01 Sieve Tray Tower 1 buah Kontinyu Memisahkan etanol dan air DATA DESAIN Top 0,600 Atm 67,096 oC
Bottom 1,00 Atm 98,787 oC
KOLOM Tinggi kolom Material Diameter Tray spacing Jumlah tray Tebal silinder Tebal head
Downcomer area Active area Hole Diameter Hole area Tinggi weir Panjang weir Tebal pelat Pressure drop per tray
12,541 m Carbon Steel Top 1,435 M 0,500 M 8,000 Buah 0,004 M 0,004 M PELAT Top 2 0,213 m 2 1,350 m 5,000 Mm 2 0,135 m 50,000 Mm 1,143 M 5,000 Mm 110,850 mm liquid
Bottom 1,095 m 0,500 m 10,000 buah 0,004 m 0,004 m Bottom 2 0,113 m 2 0,715 m 5,000 mm 2 0,072 m 50,000 mm 0,832 m 5,000 mm 68,653 mm liquid
Tipe aliran cairan Desain % flooding Jumlah hole
17.
Single pass 85,000 % 6.879,000 Buah
Single pass 85,000 % 3.646,000 Buah
KOLOM DESTILASI - 02 (KD-02)
Dengan Perhitungan yang sama untuk Kolom Distilasi selanjutnya analog dengan perhitungan Kolom Distilasi KD-01. Nama Alat Alat Kode Jenis Jumlah Operasi Fungsi
Tekanan Temperatur
IDENTIFIKASI Kolom Destilasi KD-02 Sieve Tray Tower 1 buah Kontinyu Memisahkan etanol dan etil asetat DATA DESAIN Top Bottom 0,370 atm 1,00 Atm 55,071 oC 78,335 oC KOLOM
Tinggi kolom Material Diameter Tray spacing Jumlah tray Tebal silinder Tebal head
Downcomer area Active area Hole Diameter Hole area Tinggi weir
20,040 m Carbon Steel Top 1,245 m 0,500 m 6,000 Buah 0,284 m 0,232 m PELAT Top 2 0,146 m 2 0,924 m 5,000 Mm 2 0,092 m 50,000 mm
Bottom 2,916 m 0,500 m 32,000 buah 0,005 m 0,005 m Bottom 2 0,801 m 2 5,073 m 5,000 mm 2 0,507 m 50,000 mm
Panjang weir Tebal pelat Pressure drop per tray Tipe aliran cairan Desain % flooding Jumlah hole 18.
0,946 m 5,000 mm 323,196 mm liquid Single pass 85,000 % 44.415,000 Buah
2,216 m 5,000 mm 481,872 mm liquid Single pass 85,000 % 51.609,000 Buah
KOMPRESOR- 01 (K-01)
Fungsi
: Untuk menaikkan tekanan keluaran MP-01
Tipe
: Centrifugal Compressor
Gambar
:
1. Data : Laju alir massa (w)
=
57407,4074
Densitas ()
=
9,3578 kg/m3
=
1,0004
k =
Cp campuran Cp cam R
2. Kondisi Operasi : Tekanan, Pin Pout Temperatur, Tin 3. Volumetric Flowrate, Q Q
=
W
= 1 atm = 5 atm = 118,100 0C
kg/jam
= 3611,3592 ft3/min 4. Power Kompresor (Pw) Pw
0,0643 k T Q1 = 520 (k 1)
P 2 P1
( k 1) / k
1
(McCabe, 2009)
Dimana : K
= 1,0004
= 0,8000
P2
= 5 atm
P1
= 1 atm
Q
= 3611,3592 ft3/min
Pw
0,0643 .(1,2071) .(91). (15102,3040 = 520 (1,2071 1) 0,80
) 2 1
1, 2071 1 / 1, 2071
1
= 93,3970 Hp 5.
Rasio Kompresi, Rc Rc
= (Pout / Pin)
(E. E. Ludwig, 1999)
= (5 atm / 1 atm) = 5,000 Jumlah stage, n
=1
Rc perstage
= (Rc)1/n = (5)1/1 = 5
6.
Pada Stage 1 Pi
= 1 atm
RC1
= (Po* / Pi)
Maka : Po*
= Rc1 x Pi = 5 x 1 atm = 5,000 atm
(E. E. Ludwig, 1999)
Temperatur yang keluar dari Kompressor stage 1 : T2
= T1 P2 p
1
( K 1) / Kn
(E. E. Ludwig, 1999)
= TinRc(K-1)/Kn = 118,1749 oC 7.
Kapasitas Kompressor Laju alir volumetrik
= 3611,3592 ft3/min
faktor keamanan
= 10%
maka : kapasitas kompressor
= (100% + 10%) x 3611,3592 ft3/min = 3972,4951 ft3/min IDENTIFIKASI
Nama Alat
Kompresor 01
Kode Alat
K-01
Jumlah
1 buah
Fungsi
Untuk mengalirkan & menaikkan tekanan gas dari Vaporizer-01 menuju Mixing Point-02 DATA DESIGN
Tipe Temperature design Tekanan design Kapasitas
Centrifugal Compressor 118,175
o
C
5 Atm 3972,495 ft3/min DATA MEKANIK
Temperatur keluar
118,175
o
C
Tekanan masuk
1 Atm
Tekanan keluar
5 Atm
Power Bahan konstruksi
93,397 Hp Carbon and Steel Alloy
19.
KOMPRESOR - 02 (K-02)
Dari perhitungan yang sama maka untuk kompressor selanjutnya dihitung dengan cara analog dengan perhitungan kompressor K-01. IDENTIFIKASI Nama Alat
Kompresor 02
Kode Alat
K-02
Jumlah
1 buah
Fungsi
untuk mengalirkan dan menaikkan tekanan gas dari mixing point-02 menuju reaktor-01 DATA DESIGN
Tipe Temperature design Tekanan design Kapasitas
Centrifugal Compressor 299,257
o
C
18 Atm 3972,495 ft3/min DATA MEKANIK
Temperatur keluar
118,175
o
C
Tekanan masuk
5 Atm
Tekanan keluar
18 Atm
Power Bahan konstruksi
299,257 Hp Carbon and Steel Alloy
20.
PARTIAL CONDENSOR - 01 (PC-01) Fungsi
: Mengubah sebagian fase crude etanol sebelum masuk FD-01
Tipe
: Shell and Tube Heat Exchanger
Gambar
: Aliran inlet Tube
Head
Fluida Panas
Shell
Rear End Aliran outlet
Water in
: Produk reaktor-01
W
= 66.804,593 kg/hr
= 147.278,740 lb/hr
T1
= 155 oC
= 311,000 oF
T2
= 155 oC
= 311,000 oF
Fluida Dingin
: Air Pendingin
w
= 85.202,804 kg/hr
= 187.839,805 lb/hr
t1
= 28 oC
= 82,400 oF
t2
= 50 oC
= 122,000 oF
Perhitungan design sesuai dengan literatur pada buku Donald Q. Kern (1965). 1. Beban Panas PC-01 Q
= 17.853.473,026 kJ/hr = 16.922.075,190 Btu/hr
2. LMTD
Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
311,000
Suhu tinggi
122,000
189,000
311,000
Suhu rendah
82,400
228,600
Selisih
LMTD =
-39,600
t 2 t1 ln (t 2 / t1 )
= 288,600 oF Ft
=1
t
= 228,600 oF
(Fig.18, Kern)
3. Temperatur Rata-rata Tavg =
T1 T 2 2
= 311,000 oF tavg
=
t1 t 2 2
= 102,200 oF 4. Menentukan luas daerah perpindahan panas Asumsi UD = 80 Btu/hr.ft2.oF A
= =
(Tabel 8, Kern)
Q U D . t 16.922.075,190 80 𝑥 228,600
= 925,310 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger 5. Spesifikasi tube dan shell
Tube Side
= Aliran bahan baku asam asetat dari T-01
Panjang tube (L)
= 16 ft
Outside Diameter (OD) = 1,25 in BWG
= 18
Pass
=4
a”
= 0,2618 ft2/lin ft A L x a"
Jumlah tube, Nt
= =
925,310 16 𝑥 0,2618
= 220,900
Dari tabel. 9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt
= 217
Corrected Coefficient, UD A
= Nt x L x a'' = 217 x 16 ft x 0,2618 ft2 = 908,969 ft2
UD
=
Q U D . t
= 81,44 karena nilai Ud perhitungan mendekati nilai Ud asumsi, maka data untuk shell : Shell
= Air pendingin
ID
= 29 inch
(Tabel 9, Kern)
Baffle Space (B = ID/2) = 14,50 inch Pass
=4
Pt
= 1,5625
in triangular pitch
6. Perhitungan desain bagian tube
Flow Area/tube, a’t a’t
= 1,040 in2
(Tabel 10, Kern)
at
=
Nt a ' t 144 n
(Pers. 7.48, Kern)
217 𝑥 1,040
=
144 𝑥 4
= 0,3918 ft2
Laju Alir, Gt Gt
= W/at
=
147.278,740 0,3918
= 375.897,530 lb/hr.ft2
Bilangan Reynold, Ret μ
= 0,0147 cp
ID
= 1,150 inch = 0,0958 ft
Ret
= ID.Gt/ μ
= 0,0355 lb/ft hr (Tabel 10, Kern)
= 1.014.706,845
Dengan L/D = 166,956 diperoleh Jh = 1000
(Fig.24, Kern)
Nilai hi CP
= 0,0027 Btu/lb.oF
k
= 0,0610 Btu/hr ft.oF
c. k
= 0,0016
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
= 74,334 Btu/hr ft2 oF
hio
= hi x ID/OD
7. Perhitungan desain bagian shell ID = Diameter dalam shell
= 29 in
B = Baffle spacing
= 14,50 in
Pt = tube pitch
= 1,5625 in = Pt – OD = 1,5625 – 1 = 0,3125 in
Flow Area, as
=1
(Pers. 6.5, Kern)
= 68,387 Btu/hr.ft2.oF
C’ = Clearance
0 ,14
= ID x C’B/144 PT
as
=
29 x 0,3125 x 14,50 144 𝑥 1,5625
= 0,584 ft2
Laju Alir, Gs Gs
= w/as =
427.400,031 𝑙𝑏/ℎ𝑟 0,584 ft2
= 731.814,560 lb/hr.ft2
Bilangan Reynold, Res de
= 0,910 in
(Fiq.28 Kern)
De (Equivalent diameter) = 0,076 ft μ
= 0,664 cp
Res
=
= 1,607 lb/ft hr
GS De
= 34.536,454 Maka: jH
= 120
(Fig.28, Kern)
Nilai ho Cp
= 0,0037 Btu/lb.oF
k
= 0,3642 Btu/hr ft.oF
Cp. k
1
3
= 0,2536
Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3 = 146,181 Btu / hr ft2 oF
8. Clean Overall Coefficient, UC UC
=
hio ho hio ho
= 46,591 Btu/hr.ft2.oF 9. Dirt Factor, Rd
Rd
=
U C U D U C U D
= 0,009 hr.ft2.oF/Btu
10. Pressure drop
Bagian tube Untuk NRe
= 1.014.706,845
Faktor friksi
= 0,0001
s
= 0,1821
ΔPt
f Gt 2 L n = 5, 22 x 10 10 x De s f t
(Fig 26, Kern)
= 0,2482 psi V2 / 2g
= 0,02
ΔPr
= ( 4n/s ) ( V2/2g )
(Fig 27, Kern)
= 1,7572 Psi ΔPT
= ΔPt + ΔPr = 0,2482 psi + 1,7572 Psi = 2,0053 psi
Shell Side Re
= 34.536,455
f
= 0,0015
N+1
= 12 L / B = 158,900
Ds
= 2,4167 ft
s
=1
ΔPs
=
fGs2 Ds ( N 1) 5,22 1010 Desf s
= 7,793 psi
(Fig.29, Kern)
IDENTIFIKASI Nama Alat
Parsial Condensor-01
Kode
PC-01
Jumlah
1
Fungsi
Mengubah fase keluaran R-01
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
46,591
Btu/hr ft2 oF
Ud
81,438
Btu/hr ft2 oF
Rd Calculated
0,009
hr ft2 oF/Btu
TUBE SIDE Length OD
16
Ft
1,25
In
Passes
4
BWG
18
Pitch
1,5625
Nt ΔPT
217 2,005
in Triangular Pitch tubes Psi SHELL SIDE
ID
29
in
B
14,5
in
Passes ΔPs
4 7,793
psi
21.
POMPA- 01 (P-01)
Fungsi
: Mengalirkan larutan asam asetat menuju Vaporizer (VP-01)
Tipe
: Centrifugal pump
Bahan Konstruksi
: Carbon Steel
Gambar
:
Data Desain Temperatur, T
: 30 C
Flowrate, ms
: 2870,3704 kg/jam
Densitas fluida,
: 884,600 kg/m3
Viskositas,
: 0,3993 cp
Tekanan uap, Puap
: 122,0567 mmHg
Faktor keamanan, f
: 10 %
1. Kapasitas Pompa, Qf mf
= (1+ f ) x ms = (1 + 0,01) x 2870,3704 lb/jam = 120,7106 lb/min
Qf
= =
mf
120,7106 lb/min 58,553 𝑙𝑏/𝑓𝑡 3
= 2,0616 ft3/min = 0,0344 ft3/sec = 15,4216 gal/min
2. Menentukan Ukuran Pipa Diameter Pipa Untuk aliran turbulent yang mempunyai range viskositas 0,02 – 20 cp maka digunakan rumus diameter dalam optimum pipa Dopt = 3,9 Qf 0,45 x 0,13
(Peter, 1991)
= 3,9 x (0,0344 ft3/sec)0,45 x 58,553 lb/ft3) 0,13 = 1,4523 in Dari tabel 10-18 Properties of steel pipe, Perry's chemical Engineers' Handbook, hal 10-72 – 10-74, dimensi pipa yang digunakan adalah : a) Untuk Suction Pipe IPS
= 2,5 in
SN
= 40
ID
= 2,469 in
OD
= 2,875 in
Ls
=3m
a”
= 1,704 in2
b) Untuk Discharge Pipe IPS
= 2 in
SN
= 40
ID
= 2,067 in
OD
= 2,375 in
Ld
=7m
a”
= 0,023 in2
3. Perhitungan Pada Suction a. Suction friction loss Suction velocity Vs
=
Qf a"
= 1,474 ft/sec = 5308,748 ft/jam
V2 2 gc
= 0,0338 ft. lbf/lb
Reynold Number NRe
=
D .V .
= 90.086,3962 Material yang digunakan untuk konstruksi pipa adalah “Commercial Steel Pipe” Dari figure 14-1. Fanning friction factors for long straight pipes. Peter, hal 482, diperoleh : Equivalent roughness, = 0,0002 ft
D
=
0,0002 𝑓𝑡 0,256 𝑓𝑡
= 0,0009 Pada NRe = 90.086,3962 dan ε/D = 0,0009, dari figure 14-1. Fanning friction factors for long straight pipes. Peter, hal 482, diperoleh : fanning factor, f = 0,0045
b. Skin friction loss, Hfs
H
fs
2 f L V2 x D gc
(Peter, 1991)
Equivalentlength dari fitting dan valve diperoleh dari Tabel II.1 Alat Industri Kimia, Prof. Dr. Ir. Syarifuddin Ismail, hal 35 : Elbow 90o std
: 32
Gate valve
:7
jadi equivalent length dari fitting dan valve = 1 elbow 90o std + 1 gate valve = 2 (32)+ 1 (7) = 71
L
= Ls + (Lfitting . ID) = 0,0009 ft
Maka :
2 f L V2 H x fs D gc = 0,069 ft. lbf/lb c. Sudden Contraction Friction Loss, Hfc
H
fc
Kc V 2 2α gc
(Peter, 1991)
Dimana : Kc
= 0,4 (1 – Sb / Sa)
Sa
= Luas penampang 1
= A>>>
Sb
= Luas penampang 2,
= A <<<
= 1 untuk aliran turbulent
Sb/ Sa diabaikan karena luas Sa sangat besar dibandingkan dengan luas Sb Maka : Kc
= 0,4 (1– A2/A1 ) = 0,4 (1-1) = 0,4
H
fc
Kc x
1 V2 x 2 gc
= 0,0068 ft. lbf/lb
d. Fitting dan Valve Friction Loss, Hff
H
ff
Kf x
V2 2 gc
(Pers. II.7, Syarifuddin)
Nilai Kf diperoleh dari Tabel II.2 Alat Industri Kimia, Prof. Dr. Ir. Syarifuddin Ismail, hal 35 : Elbow 90o std
: 0,9
Gate valve, wide open : 0,2 Kf = 2 elbow 90o std + 1 gate valve
= 1 (0,9) + 1 (0,2) =2
V2 H Kf x ff 2 gc = 0,0676 ft.lbf/lb
e. Total Suction Friction Loss, Hf suc Hf suc
= Hfs + Hfc + Hff = 0,1177 ft. lbf/lb D
A
VZ-01
T-01
C B
P-01
f. Suction Head, Hsuc
Pa Pb
2 2 g Za Zb Va Vb Hf gc 2 g
Za
=3m
Zb
=0m
Static suction, Zs
= Za – Zb
g/gc
= 1 lbf/lb
static suction head, Hs
=
= 9,8425 ft
g Za Zb gc
= 1 lbf/lb x 9,8425 ft = 9,8425 ft. lbf/lb
Pressure head, Hp : Pa
= 1 atm
= 14,6960 psi = 2.116,2240 lbf/ft2
Pa
= 72,2841 ft. lbf/lb
Velocity head, Hv Va – Vb = 0 Hv
= 0 ft. lbf/lb
Maka :
Pa Pb
g Va 2 Vb2 Za Zb Hf gc 2 g
g Va 2 Vb2 ( Za Zb) + = + - Hf gc 2 g
Pb Pb
Pa
= 82,0090 ft. lbf/lb
Pb = 4801,8676 lbf/ft2 = 33,3463 psi g. Net Positive Suction Head (NPSH) Vapor Pressure Corection, Hp uap Hp uap
=
Puap
= 67,3031 ft/lbf/lb Total NPSH
= Hsuc - Hp uap = 14,7059 ft/lbf/lb
4. Perhitungan Pada Discharge a. Discharge friction loss Discharge velocity Vd
=
Qf a"
= 2,4299 ft/sec = 8747,7953 ft/jam
V2 2g c
= 0,0918 ft. lbf/lb
Reynold Number, NRe =
D .V .
= 115624,8347 Material yang digunakan untuk konstruksi pipa adalah “Commercial Steel Pipe” Dari figure 14-1. Fanning friction factors for long straight pipes. Peter, hal 482, diperoleh : Equivalent roughness, = 0,0002 ft
D
= 0,0011
Pada NRe = 115.501,3240 dan ε/D = 0,001, dari figure 14-1. Fanning friction factors for long straight pipes. Peter, hal 482, diperoleh : fanning factor, f = 0,0045
b. Skin friction loss, Hfs
2 f L V2 H x fs D gc
(Peter, 1991)
Equivalent length dari fitting dan valve diperoleh dari Tabel II.1 Alat Industri Kimia, Prof. Dr. Ir. Syarifuddin Ismail, hal 35 : Elbow 90o std
: 32
Gate valve
:7
jadi equivalent length dari fitting dan valve
= 2 elbow 90o std + 1 gate
valve = 71 L
= Ls + (Lfitting . ID)
= 0,200 ft Maka :
2 f L V2 H x fs D gc = 0,200 ft. lbf/lb c. Sudden Contraction Friction Loss, Hfc
H
fc
Kc V 2 2α gc
(Peter, 1991)
Dimana : Kc = 0,4 (1 – Sb / Sa) Sa
= Luas penampang 1
= A>>>
Sb = Luas penampang 2,
= A <<<
= 1 untuk aliran turbulent
Sb/ Sa diabaikan karena luas Sa sangat besar dibandingkan dengan luas Sb Maka : Kc
= 0,4 (1 – A2/A1 ) = 0,500
1 V2 H Kc x x fc 2 gc = 0,0229 ft. lbf/lb d. Fitting dan Valve Friction Loss, Hff
H
ff
Kf x
V2 2 gc
(Pers. II.7, Syarifuddin)
nilai Kf diperoleh dari Tabel II.2 Alat Industri Kimia, Prof. Dr. Ir. Syarifuddin Ismail, hal 35 : Elbow 90o std
: 0,9
Gate valve
: 1,8
jadi nilai Kf
= 2 elbow 90o std + 1 gate valve =2
H
ff
Kf x
V2 2 gc
= 0,0918 ft . lbf/lb
e. Total Discharge Friction Loss, Hf dis Hf dis = Hfs + Hfc + Hff = 0,3147 ft. lbf/ lb D
A
V-01
T-01
C B
P-01
g. Suction Head, Hsu
Pc Pd
2 2 g Zc Zd Vc Vd Hf gc 2 g
Zc
=0m
Zd
=4 m
Static suction, Zs
= Zd – Zc = 13,1234 ft
g/gc
= 1 lbf/lb
static suction, head, Hs
=
g Zd Zc gc
= 1 lbf/lb x 13,1234 ft = 13,1234 ft. lbf/lb Pressure head, Hp :
Pd
= 1,1 atm
Pd
=
2327,838 lbf/ft2 64,835 lb/ft 3
= 79,5125 ft. lbf/lb
Velocity head, Hv Vc – Vd = 0 Hv
= 0 ft. lbf/lb
Maka :
Pc Pd
Pc
Pc
Pc
=
Pd
2 2 g Zc Zd Vc Vd Hf gc 2 g
+
g Vd 2 Vc 2 ( Zd Zc) + - Hf gc 2 g
= 92,3212 ft. lbf/lb = 92,3212 = 5405,6775 = 37,5394
ft. lbf/lb x lbf/ft2 Psi
64,835 lb/ft3
h. Net Positive Suction Head (NPSH) Vapor Pressure Corection, Hp uap Hp uap
=
=
Puap
53,619 lbf/ft 2 64,835 lb/ft 3
= 0,827 ft Total NPSH
= Hsuc - Hp uap = (13,1234 ft – 0,827 ft) = 12,2964 ft
5. Differential Pressure (Total Pump), ΔP
Differential pressure = Discharge pressure – Suction pressure = 4,1931 psi 6. Total Head = Discharge head – Suction head
Total head
= 10,3122 ft. lbf/lb 7. Effisiensi Pompa, Kapasitas pompa, Qf = 15,4216 gal/min Efisiensi pompa diperoleh dari figure 14-37 efficiencies of centrifugal pump, Peters 4th edition hal 520 diperoleh: Effisiensi pompa, = 61 % 8. Break Horse Power (BHP) Persamaan Bernoulli : Ws
=
P
Z
V 2 H f 2 gc
= 10,3122 ft.lbf/lb
m f Ws p
BHP
=
BHP
= 2894,8665 ft. lbf/min = 0,0877 Hp
9. Requirement Driver (Besarnya Tenaga Pompa) MHP =
BHP Effisiensi motor
Dari gambar 14-38, efficiencies of three-phase motor, Peter (hal 521) diperoleh : Effisiensi motor
= 80%
Jadi : MHP
= 0,1097 Hp
Dipilih pompa
= 1 Hp
IDENTIFIKASI Fungsi
Mengalirkan larutan etil asetat menuju Mixing Point (MP-01)
Tipe
Centrifugal Pump
Temperatur. oC
30,000
Densitas. kg/m3
937,928
Laju alir massa. kg/jam
2986,549
Viskositas. Cp
0,245
Tekanan uap. Psi
1415,262
Safety factor. %
10%
Kapasitas pompa. gal/min
15,421
Volumetric Flowrate. ft3/det
0,034 SUCTION
DISCHARGE
NPS. In
2
1,5
SN
40
40
ID. In
2,067
1,610
OD. In
2,375
1,900
3
7
Velocity.ft/s
1,475
6,835
Total friction loss. ft, lbf/lb
0,118
0,315
Tekanan operasi. Psi
33,346
37,539
L. m
NPSH. ft, lbf/lb
14,706
Required motor driver. Hp
1,000
Jumlah
1 buah
Bahan
Carbon steel
Dengan perhitungan yang sama maka untuk pompa selanjutnya dilakukan perhitungan cara analog dengan perhitungan pompa P-01. 22.
POMPA- 02 (P-02) IDENTIFIKASI
Fungsi
Mengalirkan larutan asam asetat menuju Mixing Point (MP-01)
Tipe
Centrifugal Pump
Temperatur. oC
30,000
Densitas. kg/m3
1.054,000
Laju alir massa. kg/jam
54.537,037
Viskositas. Cp
0,909
Tekanan uap. Psi
19,256
Safety factor. %
10%
Kapasitas pompa. gal/min
250,599
Volumetric Flowrate. ft3/det
0,558 SUCTION
DISCHARGE
NPS. In
3
1,5
SN
40
40
ID. In
3,068
1,610
OD. In
3,500
1,900
4
7
Velocity.ft/s
10,884
6,835
Total friction loss. ft, lbf/lb
3,890
0,315
Tekanan operasi. Psi
17,416
21,049
L. m
NPSH. ft, lbf/lb
37,299
Required motor driver. Hp
1,000
Jumlah
1 buah
Bahan
Carbon steel
23.
POMPA- 03 (P-03) IDENTIFIKASI
Fungsi
Mengalirkan larutan dari Kd-01 yang masuk ke Reboiler menuju Utilitas
Tipe
Centrifugal Pump
Temperatur. oC
98,787
Densitas. kg/m3
166,458
Laju alir massa. kg/jam
18.163,581
Viskositas. Cp
0,987
Tekanan uap. Psi
1.480,708
Safety factor. %
10%
Kapasitas pompa. gal/min
528,476
Volumetric Flowrate. ft3/det
1,177 SUCTION
DISCHARGE
NPS. In
3,5
1,5
SN
40
40
ID. In
3,55
1,610
OD. In
4
1,900
L. m
5
7
Velocity.ft/s
17,14
6,835
Total friction loss. ft, lbf/lb
14,084
0,315
Tekanan operasi. Psi
29,086
31,738
NPSH. ft, lbf/lb
6,288
Required motor driver. Hp
2,000
Jumlah
1 buah
Bahan
Carbon steel
24.
POMPA- 04 (P-04) IDENTIFIKASI
Fungsi
Mengalirkan Produk Etanol menuju tangki penyimanan produk
Tipe
Centrifugal Pump
Temperatur. oC
72,982
Densitas. kg/m3
169,987
Laju alir massa. kg/jam
34.490,947
Viskositas. Cp
0,9988
Tekanan uap. Psi
654,206
Safety factor. %
10%
Kapasitas pompa. gal/min
982,693
Volumetric Flowrate. ft3/det
2,189 SUCTION
DISCHARGE
NPS. In
3,5
3
SN
40
40
ID. In
3,55
3,07
OD. In
4
3,5
L. m
5
5
Velocity.ft/s
31,869
42,679
Total friction loss. ft, lbf/lb
35,432
49,512
Tekanan operasi. Psi
12,810
15,195
NPSH. ft, lbf/lb
2,170
Required motor driver. Hp
2,500
Jumlah
1 buah
Bahan
Carbon steel
25.
POMPA- 05 (P-05) IDENTIFIKASI
Fungsi
Mengalirkan Produk Etanol menuju refluks Kolom destilasi
Tipe
Centrifugal Pump
Temperatur. oC
55,071
Densitas. kg/m3
150,786
Laju alir massa. kg/jam
4.197,151
Viskositas. Cp
0,9988
Tekanan uap. Psi
654,206
Safety factor. %
10%
Kapasitas pompa. gal/min
134,810
Volumetric Flowrate. ft3/det
0,300 SUCTION
DISCHARGE
NPS. In
3,5
3
SN
40
40
ID. In
3,55
3,07
OD. In
4
3,5
L. m
5
5
Velocity.ft/s
4,372
5,855
Total friction loss. ft, lbf/lb
0,667
0,932
Tekanan operasi. Psi
15,296
18,646
NPSH. ft, lbf/lb
40,471
Required motor driver. Hp
1,000
Jumlah
1 buah
Bahan
Carbon steel
26.
POMPA- 06 (P-06) IDENTIFIKASI
Fungsi
Mengalirkan Produk Etanol menuju Tanki
Tipe
Centrifugal Pump
Temperatur. oC
55,071
Densitas. kg/m3
150,786
Laju alir massa. kg/jam
4.197,151
Viskositas. Cp
0,9988
Tekanan uap. Psi
654,206
Safety factor. %
10%
Kapasitas pompa. gal/min
250,310
Volumetric Flowrate. ft3/det
0,557 SUCTION
DISCHARGE
NPS. In
3,5
3
SN
40
40
ID. In
3,55
3,07
OD. In
4
3,5
L. m
5
5
Velocity.ft/s
8,118
10,871
Total friction loss. ft, lbf/lb
2,299
3,212
Tekanan operasi. Psi
15,189
18,497
NPSH. ft, lbf/lb
38,840
Required motor driver. Hp
1,000
Jumlah
1 buah
Bahan
Carbon steel
27.
REAKTOR - 01 (R-01)
Fungsi
: Sebagai tempat terjadinya reaksi antara Asam Asetat, Etil Asetat dan Hidrogen menjadi Etanol dan Air.
Tipe
: Fixed Bed Multi Bed Reactor
Operasi
: Kontinyu
Gambar
:
Kondisi Operasi : Temperatur, T
= 274,726 oC
Tekanan, P
= 18 atm
Konversi Asam Asetat bed 1 = 80 % Konversi Asam Asetat bed 2 = 90 % Konversi Etil Asetat bed 1 = 5 % Konversi Etil Asetat bed 2 = 95 % Laju alir massa, W
= 66804,593 kg/jam
BM rata-rata, BMav
= 38,477 kg/mol
Densitas Campuran,
= 5,52 kg/m3
Viskositas Campuran,
= 0,0073 kg/m.s
Data Katalis :
Bed 1 Nama katalis
= Platinum (Pt) –Timah (Sn)
Porositas (Φ)
= 0,42
Diameter katalis (dp)
= 0,003 mm = 3,000 m = 2845,8923 kg/m3
Densitas katalis Bed 2 Nama katalis
= CuZn-Al2O3
Porositas (Φ)
= 0,42
Diameter katalis (dp)
= 0,003 mm = 3,000 m = 2845,8923 kg/m3
Densitas katalis Reaksi yang terjadi
:
Bed 1 CH3COOH + 2H2
CH2H5OH + H2O
CH3COOH
C2H8O2 + H2O
+ C2H8O2
C2H8O2 + 2H2
2CH2H5OH
CH3COOH + 2H2
CH2H5OH + H2O
C2H8O2 + 2H2
2CH2H5OH
Bed 2
Perhitungan Pada Desain Reaktor Reaksi 1 1.
Volumetric Flowrate Umpan, Qf Qf Laju alir Volumetrik (Qf)
=
M
= 12.102,281 m3/jam = 3,3617 m3/s
2.
Konsentrasi mula-mula, C a) Konsentrasi umpan CH3COOH, [CAo]
Umpan masuk, (Fao)
= 907,133 kmol/jam
Konsentrasi [CAo]
=
Fao Qf
= 0,075 kmol/m3
b) Konsentrasi umpan H2, [CBo] Umpan masuk (Fbo)
= 4698,580 kmol/jam
Konsentrasi O2 [CBo]
=
Fbo Qf
= 0,389 kmol/m3 Reaksi 2 1.
Volumetric Flowrate Umpan, Qf Qf Laju alir Volumetrik (Qf)
=
M
= 12.102,281 m3/jam = 3,3617 m3/s
2.
Konsentrasi mula-mula, C a) Konsentrasi umpan CH3COOH, [CAo] Umpan masuk, (Fao)
= 181,426 kmol/jam
Konsentrasi [CAo]
=
Fao Qf
= 0,015 kmol/m3 b) Konsentrasi umpan C2H5OH, [CBo] Umpan masuk (Fbo)
= 725,706 kmol/jam
Konsentrasi O2 [CBo]
=
Fbo Qf
= 0,060 kmol/m3 Reaksi 3
1.
Volumetric Flowrate Umpan, Qf Qf Laju alir Volumetrik (Qf)
=
M
= 12.102,281 m3/jam = 3,3617 m3/s
2.
Konsentrasi mula-mula, C a) Konsentrasi umpan CH4H8O2, [CAo] Umpan masuk, (Fao)
= 68,870 kmol/jam
Konsentrasi [CAo]
=
Fao Qf
= 0,0057 kmol/m3 b) Konsentrasi umpan H2, [CBo] Umpan masuk (Fbo)
= 3247,168 kmol/jam
Konsentrasi O2 [CBo]
=
Fbo Qf
= 0,2683 kmol/m3 Reaksi 4 1.
Volumetric Flowrate Umpan, Qf Qf Laju alir Volumetrik (Qf)
=
M
= 12.102,281 m3/jam = 3,3617 m3/s
2.
Konsentrasi mula-mula, C a) Konsentrasi umpan CH3COOH, [CAo] Umpan masuk, (Fao)
= 145,141 kmol/jam
Konsentrasi [CAo]
=
Fao Qf
= 0,012 kmol/m3 b) Konsentrasi umpan H2, [CBo]
Umpan masuk (Fbo)
= 3240,281 kmol/jam
Konsentrasi O2 [CBo]
=
Fbo Qf
= 0,267 kmol/m3 Reaksi 5 1.
Volumetric Flowrate Umpan, Qf Qf Laju alir Volumetrik (Qf)
=
M
= 12.102,281 m3/jam = 3,3617 m3/s
2.
Konsentrasi mula-mula, C a) Konsentrasi umpan CH4H8O2, [CAo] Umpan masuk, (Fao)
= 65,427 kmol/jam
Konsentrasi [CAo]
=
Fao Qf
= 0,0054 kmol/m3 b) Konsentrasi umpan H2, [CBo] Umpan masuk (Fbo)
= 2979,0267 kmol/jam
Konsentrasi O2 [CBo]
=
Fbo Qf
= 0,2462 kmol/m3 3.
Residence Time
4.
Residence Time, = 0,4 _ 30 detik
(Sumber: US Patent 9,670119 B2)
Maka diambil, = 15 detik 5.
Menentukan Kinetika Reaksi Reaksi 1 : CH3COOH + 2H2
k1
Reaksi merupakan bentuk reaksi orde dua :
C2H5OH + H2O
-r1
= k1 . C A . C B
(Levenspiel, 1999)
Nilai k dapat dihitung menggunakan persamaan Arrhennius : k1
= A . e –E/RT
A
=
(Levenspiel, 1999)
1 1 A B N . 8 .R.T . 3 2 10 M A MB 2
Dimana diameter partikel : σA
= 4,3992 A
σB
= 6,0168 A = 6,0168 x 10-8 cm
= 4,3992 x 10-8 cm
(Welty, 2008 )
Berat Molekul MA
= 60,052 kg/kmol
MB
= 2,0160 kg/kmol
N (Bil. Avogadro)
= 6,02 x 1023 A
R
= 8,314
kJ/kmol.K
Menentukan Energi Aktivasi ∆Hf 298 CH3COOH
= -438.150,000 kJ/kmol
∆Hf 298 CH3OH
= 0,000 kJ/kmol
ECH3COOH
= H f 298 R T = -442.705,041 kJ/kmol = H f 298 R T
EH2
= -4.555,041 E
kJ/kmol
= (ECH3COOH + ECH3OH) /2 = -223.630,041
- E/RT
kJ/kmol
= -223.630,041 / (8,314 kJ/kmol.K) (423,15 K) = 49,095
Maka: 1 1 E / RT A B N = 2 103 8 .R.T . M M .e B A 2
k1
k1 = 3,79 x 1012 cm3/kmol.s k1 = 3,79 x 106 m3/kmol.s
(Smith, J.M, 2001)
Diketahui dari perhitungan: CAo1
= 0,075
kmol/m3
CBo1
= 0,388
kmol/m3
X
= 0,800
k1
= 3,79 x 106 m3/kmol.s
Menghitung laju reaksi: -r1
= k1[CA][CB]2
-r1
= k1 . CAO2 (1 – X) (M – X)
-r1
= 9,592 x 108 kmol/m3.s
Reaksi 2 : k2
CH3COOH + C2H5OH
C4H8O2
Reaksi merupakan bentuk reaksi orde dua : -r2
= k2 . C A . C B
(Levenspiel, 1999)
Nilai k dapat dihitung menggunakan persamaan Arrhennius : k2
= A . e –E/RT
A
= A B N
(Levenspiel, 1999)
1 1 . 8 .R.T . 3 10 M A MB 2
2
Dimana diameter partikel : σA
= 2,573 A
σB
= 30,247 A = 3,0248 x 10-7 cm
= 2,5728 x 10-8 cm
(Welty, 2008 )
Berat Molekul MA
= 60,052 kg/kmol
MB
= 46,069 kg/kmol
N (Bil. Avogadro)
= 6,02 x 1023 A
R
= 8,314
kJ/kmol.K
Menentukan Energi Aktivasi ∆Hf 298 CH3COOH
= -438.150,000 kJ/kmol
∆Hf 298 C2H5OH
= -235,310 kJ/kmol
= H f 298 R T
ECH3COOH
= -442.705,041 kJ/kmol = H f 298 R T
EC2H5OH
= -4.790,351 kJ/kmol E
= (ECH3COOH + EC2H5OH) /2 = -223.747,696
- E/RT
kJ/kmol
= -223.747,696 / (8,314 kJ/kmol.K) (423,15 K) = 49,120
Maka: 1 1 E / RT A B N = 2 103 8 .R.T . M M .e B A 2
k2
(Smith, J.M, 2001)
k2 = 2,313 x 1013 cm3/kmol.s k2 = 2,313 x 107 m3/kmol.s Diketahui dari perhitungan: CAo2
= 0,015
kmol/m3
CBo2
= 0,388
kmol/m3
X
= 0,050
k2
= 2,313 x 107 m3/kmol.s
Menghitung laju reaksi: -r2
= k2[CA][CB]2
-r2
= k2 . CAO2 (1 – X) (M – X)
-r2
= 2,6984 kmol/m3.s
Reaksi 3 : C4H8O2
k3
+ H2
C2H5OH
Reaksi merupakan bentuk reaksi orde dua : -r3
= k3 . C A . C B
(Levenspiel, 1999)
Nilai k dapat dihitung menggunakan persamaan Arrhennius : k3
= A . e –E/RT 2 A B N
2
1 1 . 8 .R.T . 3 10 M A MB
(Levenspiel, 1999)
A
=
Dimana diameter partikel : σA
= 2,2306 A
= 2,2306 x 10-8 cm
σB
= 5,3196 A
= 5,3196 x 10-8 cm
(Welty, 2008 )
Berat Molekul MA
= 88,206 kg/kmol
MB
= 2,0159 kg/kmol
N (Bil. Avogadro)
= 6,02 x 1023 A
R
= 8,314 kJ/kmol.K
Menentukan Energi Aktivasi ∆Hf 298 C4H8O2
= -426,800 kJ/kmol
∆Hf 298 H2
= 0,000 kJ/kmol
EC4H8O2
= H f 298 R T = -4.981,841 kJ/kmol = H f 298 R T
EH2
= -4.555,041 kJ/kmol E
= (ECH3COOH + EC2H5OH) /2 = -4.768,441
- E/RT
kJ/kmol
= -4.768,441 / (8,314 kJ/kmol.K) (423,15 K) = 1,0468
Maka: K3
1 1 E / RT A B N .e 8 .R.T . = 3 2 10 MA MB 2
2001) K3 = 4,467 x 1012 cm3/kmol.s K3 = 4,467 x 106 m3/kmol.s Diketahui dari perhitungan: kmol/m3
CAo1
= 0,0057
CBo1
= 0,2683 kmol/m3
X
= 0,050
(Smith, J.M,
= 4,467 x 106 m3/kmol.s
k3
Menghitung laju reaksi: -r3
= k1[CA][CB]2
-r3
= k1 . CAO2 (1 – X) (M – X)
-r3
= 2,6984 kmol/m3.s
Reaksi 4 : k4
CH3COOH + 2H2
C2H5OH + H2O
Reaksi merupakan bentuk reaksi orde dua : -r4
= k4 . C A . C B
(Levenspiel, 1999)
Nilai k dapat dihitung menggunakan persamaan Arrhennius : k4 A
= A . e –E/RT 2 = A B N
(Levenspiel, 1999)
1 1 . 8 .R.T . 3 10 M A MB
2
Dimana diameter partikel : σA
= 2,2306 A
= 2,2306 x 10-8 cm
σB
= 5,3196 A
= 5,3196 x 10-8 cm
Berat Molekul MA
= 60,052 kg/kmol
MB
= 2,0159 kg/kmol
N (Bil. Avogadro)
= 6,02 x 1023 A
R
= 8,314 kJ/kmol.K
Menentukan Energi Aktivasi ∆Hf 298 CH3COOH
= -438,150 kJ/kmol
∆Hf 298 H2
= 0,000 kJ/kmol
ECH3COOH
= H f 298 R T = -4.993,191 kJ/kmol
EH2
= H f 298 R T = -4.555,041 kJ/kmol
(Welty, 2008 )
E
= (ECH3COOH + EC2H5OH) /2 = -4.774,116
- E/RT
kJ/kmol
= -(-4.774,116 / (8,314 kJ/kmol.K) (423,15 K) = 1,0481
Maka:
1 1 E / RT A B N .e 8 .R.T . 3 2 10 MA MB 2
k4 =
(Smith, J.M, 2001)
k4 = 2,753 x 10-9 cm3/kmol.s k4 = 2,753 x 10-15 m3/kmol.s Diketahui dari perhitungan: kmol/m3
CAo4
= 0,0120
CBo4
= 0,2677 kmol/m3
X
= 0,900
k4
= 2,753 x 10-15 m3/kmol.s
Menghitung laju reaksi: -r4
= k4[CA][CB]2
-r4
= k4 . CAO2 (1 – X) (M – X)
-r4
= 6,006-13 kmol/m3.s
Reaksi 5 : k5
C4H8O2 + 2H2
C2H5OH + H2O
Reaksi merupakan bentuk reaksi orde dua : -r5
= k5 . C A . C B
(Levenspiel, 1999)
Nilai k dapat dihitung menggunakan persamaan Arrhennius : k5 A
= A . e –E/RT 2 = A B N
2
3 10
(Levenspiel, 1999) 1 1 . 8 .R.T . M A MB
Dimana diameter partikel : σA
= 6,4187 A
= 6,4187 x 10-8 cm
σB
= 5,3196 A
= 9,1663 x 10-7 cm
Berat Molekul
(Welty, 2008 )
MA
= 88,206 kg/kmol
MB
= 2,0159 kg/kmol
N (Bil. Avogadro)
= 6,02 x 1023 A
R
= 8,314 kJ/kmol.K
Menentukan Energi Aktivasi ∆Hf 298 C4H8O2
= -426,800 kJ/kmol
∆Hf 298 H2
= 0,000 kJ/kmol
EC4H8O2
= H f 298 R T = -4.981,841 kJ/kmol = H f 298 R T
EH2
= -4.555,041 kJ/kmol E
= (ECH3COOH + EC2H5OH) /2 = -4.768,441
- E/RT
kJ/kmol
= -4.768,441 / (8,314 kJ/kmol.K) (423,15 K) = 1,0468
Maka: k5
1 1 E / RT A B N = 2 103 8 .R.T . M M .e B A 2
k5 = 9,976 x 10-7 cm3/kmol.s k5 = 9,976 x 10-13 m3/kmol.s Diketahui dari perhitungan: kmol/m3
CAo5
= 0,0054
CBo5
= 0,2462 kmol/m3
X
= 0,05
K5
= 9,976 x 10-13 m3/kmol.s
Menghitung laju reaksi: -r5
= k5[CA][CB]2
-r5
= k5 . CAO2 (1 – X) (M – X)
-r5
= 6,1034-15 kmol/m3.s
5. Menentukan Volume Reaktor
(Smith, J.M, 2001)
Mass flow rate (W)
= 66804,593 kg/jam
Densitas (ρ)
= 5,520
kg/m3
Volumetric flow rate (Q) = 12.102,281 m3/jam
1) Volume reaktor =.Q
Vf
= 0,00417 jam × 12.102,281 m3/jam = 50,4262 m3 Vr
= (1+f) Vf = 60,5114 m3
2) Menentukan Volume Katalis (Vk) dan Berat Katalis (Wk) Menghitung Volume Katalis Bed 1 f
= 0,420
VTR
= 60,5114 m3
Vk
= (1– Φ). Vr = (1– 0, 420) . 60,5114 m3
Vk
= 35,0966 m3
Menghitung Berat Katalis ρk
= 770 kg/m3
Wk
= ρk. Vk
Wk
= 2845,892 kg/m3 x 35,0966 m3 = 99.881,189 kg
Bed 2 f
= 0,450
VTR
= 60,5114 m3
Vk
= (1– Φ). Vr = (1– 0,450) . 60,5114 m3
Vk
= 33,2813 m3
Menghitung Berat Katalis
ρk
= 1,7462 kg/m3
Wk
= ρk. Vk
Wk
= 1,7462 kg/m3 x 33,2813 m3 = 58.127,6082 kg
3) Volume Total Reaktor (VRt) VRt
= Vr +Vk
VRt
= 60,5114 m3 + (35,0966 + 33,2813 m3) = 128,8893 m3
4) Menentukan Ukuran Kolom Reaktor a)
Diameter Accumulator, D Volume Silinder, Vs Vs
= (π/4) D2 HS
Dimana : HS = ¾ D
= 3/8 (π D3) Volume Ellipsoidal, Ve Ve
= (π/6) D2 He
Ve
= (1/24) π D3
Volume Total, VR VR
= VS + 2Ve
VR
= 3/8. π D3 + 2 (1/24) π .D3
VR
= 3/8 .π D3 + 2/24 .π D3
VR
= 1,4392 D3
Diameter Tangki, DR VR
DR
=(
DR
= 4,4741 m
1,4392
)1/3
b) Tinggi Silinder, Hs Hs
= 3/2 DR
Hs
= 6,7111 m
c) Tinggi Ellipsoidal, He He
= ¼ DR = 1,1185 m
Dimana : He = ¼ D
d) Tinggi Reaktor, HR HR
= Hs + 2He
HR
= 6,7111 m + 1,1185 m = 8,9481 m
10) Menentukan Tebal Dinding Reaktor, t t
(Peters, 1991)
P . Da C .2SE 0,2 . P
Dimana : Tekanan design, P
= 18 atm
Jari-jari kolom, ri
= 2,237 m
Working stress allowable, S
= 932,227 atm
(Peters, 1991)
Welding joint efficiency, E
= 0,85
(Peters, 1991)
Tebal korosi yang diizinkan, C = 0,003 m Maka : t
P . Da C .2SE 0,2 . P
t = 0,0547 m 11) Outside Diameter Reaktor, OD OD = ID + 2.t = 4,4741 m + 2 . (0,0547 m) OD = 4,5823 m 12) Menentukan Ketebalan Jaket Pendingin id
OD
H
Keterangan : Outside Diameter, OD
= 4,582 m
Tinggi Silinder, H
= 8,948 m
Diameter Reaktor beserta Jaket Bagian Dalam, id Flowrate Cooling Water (m)
= 802.808,878 kg/jam
Densitas Cooling Water ()
= 1000 kg/m3
Residence Time
= 0,0042 jam
Volumetric Flowrate
=
m
= 3,345 m3/jam Volume Jaket Cooling System
= Volumetric Flowrate x Residence Time = 3,345 m3/jam x 0,0042 jam = 0,0140 m3
VJaket
= (Volume Reaktor + Jaket) – (Volume Reaktor)
VReaktor + Jaket
=
1 1 (id ) 2 H (id ) 3 4 24
VReaktor
=
1 1 (OD ) 2 H (OD ) 3 4 24
Maka : VJaket
1 1 1 1 = (id ) 2 H (id ) 3 (OD ) 2 H (OD ) 3 24 24 4 4
0,0140 m3
=
Id
= 4,6181 m
Maka, Tebal Jaket
1 1 H id 2 OD 2 id 3 OD 3 4 24
= id – OD = 4,6181 m – 4,582 m = 0,0358 m = 3,5784 cm
IDENTIFIKASI Nama Alat
Reaktor
Alat Kode
R-01
Jenis
Multi Bed Fixed Bed Reactor
Jumlah
1 buah
Operasi
Continue Tempat bereaksi asam asetat, etil asetat dan hidrogen
Fungsi
dengan bantuan katalis Pt-Sn dan CuZn-Al2O3 membentuk crude ethanol KONDISI OPERASI
Tekanan
18 atm
Temperatur
274,726 OC Bed 1
Katalis
Pt-Sn
Volume
35,0996 m2
Material
Carbon Steel Bed 2
Katalis
CuZn- Al2O3
Material
33,2813 m2
Material
Carbon Steel DATA DESAIN
Tekanan
18 atm
Temperatur
274,726 OC
Diameter
4,474 m
OD
4,582 m
Tinggi
8,948 m
Tebal Dinding Reaktor
0,054 m
Tebal Jaket Pendingin
0,036 m
Bahan Konstruksi
Carbon Steel
28.
REBOILER- 01 (RB-01) Fungsi
: Untuk memanaskan kembali residu KD - 01
Tipe
: Shell and Tube Heat Exchanger
Gambar
:
Aliran inlet Shell
Tube
Rear End
Head
Aliran outlet
Fluida Panas
:
Water in
Steam
W
= 28,436.666kg/hr
= 62,692.044 lb/hr
T1
= 350 oC
= 662oF
T2
= 350 oC
= 662oF
Fluida Dingin
:
Residu KD - 01
w
= 59,283.325 kg/hr
= 130,697.205 lb/hr
t1
= 98,787oC
= 209,817oF
t2
= 98,787oC
=209,817oF
Perhitungan design sesuai dengan literatur pada buku Donald Q. Kern (1965). 22. Beban Panas RB-01 Q
= 25,476,409.467 kJ/hr = 24,146,872.086 Btu/hr
23. LMTD
Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
662
Suhu tinggi
209,817
452,183
662
Suhu rendah
209,817
452,183
Selisih
-
LMTD = 452,183 oF Ft
=1
t
= 452,183 oF
(Fig.18, Kern)
24. Temperatur Rata-rata Tavg =
T1 T 2 2
= 662oF tavg
=
t1 t 2 2
= 209,817oF
25. Menentukan luas daerah perpindahan panas Asumsi UD = 156 Btu/hr.ft2.oF A
=
Q U D . t
=
24,146,872.086 60 452,183
(Tabel 8, Kern)
= 890,011 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger
26. Spesifikasi tube dan shell
Tube Side
= Residu KD - 01
Panjang tube (L)
= 18,1 ft
Outside Diameter (OD) = 1 in BWG
= 18
Pass
=2
a”
= 0,302 ft2/lin ft A = L x a" 890,011 = 18,1 0,302
Jumlah tube, Nt
= 162,821 Dari tabel.9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt
= 162,821
Corrected Coefficient, UD A
= Nt x L x a'' = 162,821 x 18,1 ft x 0,302 ft2 = 890,011
UD
=
Q U D . t
= 60.000
karena nilai Ud perhitungan mendekati nilai Ud asumsi, maka data untuk shell : Shell
= steam
ID
= 31 inch
(Tabel 9, Kern)
Baffle Space (B = ID/2) = 15,5 inch Pass
=2
Pt
= 1,25 in triangular pitch
27. Perhitungan desain bagian tube
Flow Area/tube, a’t a’t
= 0,302 in2
(Tabel 10, Kern)
at
=
Nt a ' t 144 n
(Pers. 7.48, Kern)
=
162,821 0,302 144 2
= 0,170 ft2
Laju Alir, Gt Gt
= W/at =
130,697.205 0,170
= 220.955,906 lb/hr.ft2
Bilangan Reynold, Ret μ
= 0,379 cp
ID
= 0,902 inch = 0,075 ft
Ret
= ID.Gt/ μ =
= 0,917 lb/ft hr (Tabel 10, Kern)
0,075 766,764.180 0,917
= 62,890.438
Dengan L/D = 240,808 diperoleh Jh = 200
(Fig.24, Kern)
Nilai hi CP
= 41,743 Btu/lb.oF
k
= 0,347 Btu/hr ft.oF
c. k
= 4,796
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
0 ,14
0,419 1/ 3 = 200 6,501 0,075
=1
= 7.256,248 Btu/hr ft2 oF hio
= hi x ID/OD
(Pers. 6.5, Kern)
= 6.545,136 Btu/hr.ft2.oF 28. Perhitungan desain bagian shell ID = Diameter dalam shell
= 31 in
B = Baffle spacing
= 15,5 in
Pt = tube pitch
= 1,25 in
C’ = Clearance
= Pt – OD = 1,25 – 1 = 0,250 in
Flow Area, as as
= ID x C’B/144 PT =
31 0,250 15,5 144 1,25
= 0,667 ft2
Laju Alir, Gs Gs
= w/as =
147.457,379 0,667
= 220.955,906 lb/hr.ft2
Bilangan Reynold, Res de
= 0,720 in
= 0,06 ft
μ
= 0,022 cp
= 0,054 lb/ft hr
Res
= =
GS De
93,940.211x0,06 0,054
= 103,873.817
(Fiq.28 Kern)
Maka: jH
= 350
(Fig.28, Kern)
Nilai ho Cp
= 282,970 Btu/lb.oF
k
= 0,028 Btu/hr ft.oF
Cp. k
1
3
= 8,148
Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3\ = 350 x
0,028 x8,148 0,06
= 1.349,169 Btu / hr ft2 oF
29. Clean Overall Coefficient, UC UC
=
hio ho hio ho
=
3,990.751x1,349.169 3,990.751 1.349,169
= 1.008,292 Btu/hr.ft2.oF
30. Dirt Factor, Rd Rd
=
U C U D U C U D
=
1.008,292 60,000 1.008,292 x60,000
= 0,016 hr.ft2.oF/Btu
31. Pressure drop
Bagian tube Untuk NRe
= 62,890.438
Faktor friksi
= 0,00023
(Fig 26, Kern)
s
= 0,424
ΔPt
=
V2 / 2g
= 0,015
ΔPr
= ( 4n/s ) ( V2/2g )
f Gt 2 L n 5, 22 x 10 10 x De s f t
= 2,943 psi
(Fig 27, Kern)
= 0,283 Psi ΔPT
= ΔPt + ΔPr = 2,943 psi + 0,283 Psi = 3,226 psi
Shell Side Re
= 103,873.817
f
= 0,0003
N+1
= 12 L / B
(Fig.29, Kern) = 12 x (217/15,5)
= 168,155 Ds
= 2,583 ft
s
=1
ΔPs
=
fGs2 Ds ( N 1) 5,22 1010 Desf s
= 0,367 psi
IDENTIFIKASI Nama Alat
Reboiler - 01
Kode
Rb – 01
Jumlah
1
Fungsi
Untuk memanaskan kembali residu KD – 01
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
1.008,292
Btu/hr ft2 oF
Ud
24,803
Btu/hr ft2 oF
Rd Calculated
0,039
hr ft2 oF/Btu
TUBE SIDE Length
18,10
Ft
OD
1
In
Passes
2
BWG
18
Pitch
1,250
Nt ΔPT
454 0,785
in Triangular Pitch Tubes Psi SHELL SIDE
ID
31
In
B
15,5
In
Passes ΔPs
2 2,031
psi
29.
REBOILER- 02 (RB-02) IDENTIFIKASI
Nama Alat
Reboiler - 01
Kode
Rb – 01
Jumlah
1
Fungsi
Untuk memanaskan kembali residu KD – 01
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
1.008,292
Btu/hr ft2 oF
Ud
24,803
Btu/hr ft2 oF
Rd Calculated
0,039
hr ft2 oF/Btu
TUBE SIDE Length
18,10
Ft
OD
1
In
Passes
2
BWG
18
Pitch
1,250
Nt ΔPT
454 0,785
in Triangular Pitch Tubes Psi SHELL SIDE
ID
31
In
B
15,5
In
Passes ΔPs
2 2,031
psi
30.
TANGKI- 01 (T-01) Fungsi
: Menampung bahan baku hidrogen
Tipe
: Spherical tank
BahanKonstruksi
: Carbon steel
Gambar
:
a. Data Temperatur, T
: 30 oC
Tekanan, P
: 5 atm
Lajualir massa, Ws
: 3.687,754 kg
Densitas,
: 8,586 kg/m3
Faktor keamanan,f
: 10 %
Lama penyimpanan
: 3 hari
Jumlah
: 5 buah
b. KapasitasTanki,
W.t
Vt
Vt
= 30.924,564 m3
Kapasitas dalam satu tanki :
Vt(1 tanki)
=
Vt ' n tanki '
= 1.236,983 m3 Safety factor Vt’
= 10%
= (1+0,1) x Vt = 1,1 x 1.236,983 m3 = 1.484,379 m
C. Diameter Tangki Volume total, Vt = Volume bola = ( 4/3 x π R3 ) R3
= (V x 3)/(4 x 3,14) = (1.484,379 x 3)/(4 x 3,14) = 354,549 m3
R
= 7,078 m
D
= 2 x 14,155 m = 557,299 m
D. Tebal dinding tanki, t t
PxR C 2 S x E 0,2 x P
=
Dimana : P
= Tekanan design
= 220,440 psi
R
= Jari – jari kolom
= 151,496 in
S
= Working stress allowable
= 13.700 atm
Ej
= Welding joint efficiency
= 0,85
C
= Tebalkorosi yang diijinkan
= 0,013
t
= 0,892 in = 0,023 m
Outside diameter (OD)
= ID + t = 14,155 m+ 0,023 m = 14,178 m
IDENTIFIKASI Nama Alat
Tangki-01
Kode Alat
T-01
Jumlah
5 Unit
Fungsi
Tempat menyimpan bahan baku Hidrogen DATA DESAIN
Tipe
Spherical Tank
Kapasitas
1.484,379
m3
Tekanan
5
atm
Temperatur
30,000
0
Diameter
14,155
m
OD
14,178
m
Tebal Dinding
0,023
m
Bahan Konstruksi
Carbon steel
C
392.131,542
gal
31.
TANGKI - 02 (T-02) Fungsi
: Untuk menampung bahan baku Asam Asetat
Tipe
: Silinder vertical dengan head type ellipsoidal
Bahan Konstruksi
: Stainless Steel
Gambar
: He
Hs
Dt
A.
Data-data
:
Temperatur, T
: 30 OC
Tekanan, P
: 1 atm
Laju alir, Ws
: 54.537,037 kg/jam
Densitas,
: 481,113 kg/m3
Faktor keamanan,f
: 10 %
Lama penyimpanan
: 3 hari
Jumlah
:5
B.
Kapasitas Tangki, Vt Laju alir massa
Vt
=
Vt
= 8.161,634 m3
x lama persediaan
Kapasitas dalam satu tanki :
Vt(1 tanki)
Vt ' ' = n tanki = 1.632,327 m3
Volume tangki,Vt
= (1 + f) x Vt = (100% + 10%) x 1.413,390 m3 = 1.795,559 m3
C.
Diameter Tangki Volume bagian silinder, Vs 2 =r H
Vs
H = 3/2 D 2
D 3 D = 2 2
3 D3 = 8 = 1,178 D3 Volume bagian head, Vh Vh
𝜋
= 24 x D3
h=¼D
(Tabel 4, Peter, hal 538)
=0,131 D3 Jadi, Vt
= Vs + Vh = 1,178 D3 + 0,131 D3 = 1,308 D3
Dt
𝑉𝑡 1/3
= 1,308
= (1.795,559 m3/ 1,308)1/3 = 11,113 m = 218,758 in D.
Tinggi Tangki, Ht Tinggi Silinder
=H
= 3/2 D
Tinggi Head = h
= ¼ D = 2,778 m
= 16,669 m
Ht
=H+h = 16,669 m + 2,778 m = 19,448 m
E. Tebal dinding tangki,t
P. r C t S . E 0.6 P
(Table 4, hal 537,Peters and Timmerhaus)
Keterangan: P = Tekanan design
= 1 atm= 14,696 psi
R = Jari-jari vessel
= 208,504 in
S = Working stress allowable = 11.500 psi
(table 4, Peter, hal 538)
E = Joint effisiensi
= 0,85
(table 4, Peter, hal538)
C = Korosi maksimum
= 0,013 in
(table 6, Peter, hal 538)
Maka : t = 0,342 in = 0,009 m F.
Outside diameter, OD
OD
= D + 2t =11,113 m+ 2 (0,017) m = 11,130 m
IDENTIFIKASI Nama Alat
Tangki-02
Kode Alat
T-02
Jumlah
5 Unit
Fungsi
Tempat menyimpan Asam Asetat DATA DESAIN
Tipe
Silinder Vertikal dengan ellipsoidal head
Kapasitas
1.795,559
m3
Tekanan
1
Atm
Temperatur
30,00
0
Diameter
11,113
m
OD
11,130
m
Tinggi
19,448
m
Tebal Dinding
0,009
m
Bahan Konstruksi
Stainless steel
474.336,703
gal
212,078
in
63,804
ft
C
Dengan perhitungan yang sama maka untuk pompa selanjutnya dilakukan perhitungan cara analog dengan perhitungan pompa T-02. 32.
TANGKI - 03 (T-03) IDENTIFIKASI
Nama Alat
Tangki-03
Kode Alat
T-03
Jumlah
1 Unit
Fungsi
Tempat menyimpan Etil Asetat DATA DESAIN
Tipe
Silinder Vertikal dengan ellipsoidal head
Kapasitas
582,975
m3
Tekanan
1
Atm
Temperatur
30,00
0
Diameter
7,638
m
OD
7,643
M
Tinggi
13,366
M
Tebal Dinding
0,003
M
Bahan Konstruksi
Stainless steel
154,006
gal
300,706
in
43,853
ft
C
33.
TANGKI - 04 (T-04) IDENTIFIKASI
Nama Alat
Tangki-04
Kode Alat
T-04
Jumlah
5 Unit
Fungsi
Tempat menyimpan Produk Etanol DATA DESAIN
Tipe
Silinder Vertikal dengan ellipsoidal head
Kapasitas
2.022,180
m3
Tekanan
1
Atm
Temperatur
30,00
0
Diameter
11,562
m
OD
11,577
m
Tinggi
20,234
m
Tebal Dinding
0,008
m
Bahan Konstruksi
Carbon steel
534.203,422
gal
455,196
in
66,383
ft
C
34.
TANGKI - 05 (T-05) IDENTIFIKASI
Nama Alat
Tangki-05
Kode Alat
T-05
Jumlah
5 Unit
Fungsi
Tempat menyimpan Produk Etanol DATA DESAIN
Tipe
Silinder Vertikal dengan ellipsoidal head
Kapasitas
855,555
m3
Tekanan
1
Atm
Temperatur
30,00
0
Diameter
8,680
m
OD
8,691
m
Tinggi
15,190
m
Tebal Dinding
0,006
m
Bahan Konstruksi
Carbon steel
226.013,892
gal
341,724
in
49,835
ft
C
35.
VAPORIZER - 01 (VP-01) Fungsi
:Menguapkan bahan baku asam asetat.
Tipe
: Shell and Tube Heat Exchanger
Gambar
:
Aliran inlet Tube
Head
Shell
Rear End Aliran outlet
Fluida Panas
Fluida Dingin
Water in
: W
= 55.685,454 kg
= 122.765,266 lb
T1
= 350oC
= 662oF
T2
= 350oC
= 662oF
w
= 85.202,804 kg
= 187.839,806 lb
t1
= 118,100 oC
= 244,580 oF
t2
= 118,100 oC
= 244,580 oF
:
Perhitungan design sesuaidenganliteraturpada Donald Q. Kern (1965). a. Beban Panas VP-01 Q = 35.295.784,129 kJ
= 33.454.438,367 Btu
b. LMTD Fluida Panas (oF)
Fluida Dingin (oF)
Selisih
662
Suhu tinggi
244,580
417,420
662
Suhu rendah
244,580
417,420 0,000
Selisih LMTD = t= 417,420 oF Ft t
= 1,000
(Fig.18, Kern)
= 417,420 oF c. Temperatur Rata-rata Tc = 662 oF
; tc = 244,580 oF
Asumsi UD = 150 Btu/hr.ft2.oF
A =
(Tabel 8, Kern)
𝑄 𝑈𝐷 𝑋
t
A = 534,305 ft2 Karena A > 200 ft2, maka digunakan Shell & Tube Heat Exchanger
Rencana Klasifikasi -
Tube Side (Cold Fluid)
Panjang tube (L)
= 12 ft
Outside Diameter (OD) = 1 in BWG
= 18
Pass
=4
a”
= 0,2618 ft2/lin ft A L x a"
Jumlah tube, Nt
=
= 170,074 dari tabel.9 Kern, didapat nilai yang mendekati Nt perhitungan adalah Nt = 170 A
Corrected Coefficient, UD =Nt x L x a''
=534,072 ft2 UD =
Q A .Δt
UD = 150,065
(Nilai UD sudah mendekati UD asumsi)
karena nilai Ud perhitungan mendekati dengan nilai Ud asumsi, maka data untuk shell : - Shell side (Hot Fluid) ID
= 21,25 inch
(Tabel 9, Kern)
Baffle Space (B = ID/2)
= 10,625 inch
Pass
=4
Pt
= 1,25 in triangular pitch
Fluida Dingin: a. Flow Area/tube, a’t a’t = 0,639 in2
(Tabel 10, Kern)
at = Nt.a’t/144 x n = 0,189 ft2 b. Laju Alir, Gt Gt = W/at = 996.002,284 lb/hr.ft2 c.
Bilangan Reynold, Ret Pada Tavg = 244,580 oF μ = 0,876 cp
= 2,119 lb/ft hr
ID= 0,902 inch
= 0,075 ft
D = 0,0752 ft Ret = D.Gt/μ = 35.331,698 d. Dengan L/D = 159,645 diperoleh Jh = 110 e. Nilai hi
(Fig.24, Kern)
(Tabel 10, Kern)
`
Pada Tavg
= 244,580 oF
Cp
= 0,002 Btu/lb.oF
k
= 0,099 Btu/hr ft.oF
c. k
= 0,043
k Cp hi J H D k
1/ 3
w
0 ,14
Koreksi viskositas diabaikan, karena w hi
= 282,008 Btu/hr ft2 oF
hio
= hi x ID/OD
0 ,14
= 51,143 Btu/hr.ft2.oF Fluida Panas: a.
Flow Area, as as = ID x C’B/144 PT
(Pers.7.1, Kern)
ID = Diameter dalam shell
= 15,25 in
B = Baffle spacing
= 10,625 in
Pt = tube pitch
= 1,25 in
C’ = Clearance
= Pt – OD
= 1,25 – 1 = ¼ in as =
b.
15,25 0,25 7,6 = 0,161 ft2 144 1,25
Laju Alir, Gs Gs = w/as =
124.929,069 = 773.546,30 lb/hr.ft2 0,161
c. Bilangan Reynold, Res
=1
tavg
= 244oF
Cp
= 0,756Btu/lb.oF
k
= 0,115Btu/hr ft.oF
μ
= 0,325 Cp
Cp. k
1
3
= 1,753
De = 0,990 inch Res=
= 0,787lb/ft hr
= 0,083 ft
(Fig.28, Kern)
GS D
= 81.041,476 jH = 180
(Fig.28, Kern)
d. Nilai ho Koreksi viskositas diabaikan karena tidak significant, maka diperoleh : ho
= jH . (k/De). (Cpμ/k)1/3 = 422,540Btu/ hr ft2oF
e. Clean Overall Coefficient, UC UC =
hio ho = 158,783 Btu/hr.ft2.oF hio ho
f. Dirt Factor, Rd Rd =
U C U D = 0,003 hr.ft2.oF/Btu U C U D
PRESSURE DROP Tube Side 1) Untuk NRe Faktor friksi s
= 686.580,738 = 0,00011 = 0,0200
(Fig 26, Kern)
f Gt 2 L n 5, 22 x 10 10 x De s f t
2) ΔPt = = 3,906 psi 3) V2 / 2g
= 0,005
ΔPr
(Fig 27, Kern)
= ( 4n/s ) ( V2/2g ) = 3,999 psi
ΔPT
= 7,906 psi
Shell Side 1) Faktor Friksi Re
= 81.041,476
f
= 0,00017
2) Number of cross, (N + 1) N+1
= 12 L / B = 339,93
Ds
= ID / 12 = 1,270 ft s
= 1,051
ΔPs
=
fGs2 Ds ( N 1) 5,22 1010 Desf s = 9,708 psi
IDENTIFIKASI
(Fig.29, Kern)
Nama Alat
Vaporizer
Kode
VP-01
Jumlah
1
Fungsi
Untuk mengubah fase asam asetat dan etil asetat
Tipe
Shell and Tube Heat Exchanger DATA DESAIN Uc
121,158
Btu/hr ft2 oF
Ud
150,065
Btu/hr ft2 oF
Rd Calculated
0,003
hr ft2 oF/Btu
TUBE SIDE Length
12
Ft
OD
1
In
Passes
4
BWG
18
Pitch
1,250
Nt ΔPT
170 0,001
in Triangular Pitch Tubes Psi SHELL SIDE
ID
21,25
In
B
10,625
In
Passes ΔPs
4 1,762
psi