PRARANCANGAN PABRIK ALUMUNIUM SULFAT DARI ASAM SULFAT DAN KAOLIN Prarancangan Pabrik Alumunium Sulfat dari Asam Sulfat dan Kaolin Kapasitas 25.000 Ton/Tahun.

PRARANCANGAN PABRIK ALUMUNIUM SULFAT
DARI ASAM SULFAT DAN KAOLIN
KAPASITAS 25.000 TON PER TAHUN
A. HALAMAN JUDUL

Oleh :
Ahmad Masrokan
500 110 010

Dosen Pembimbing :
Ir. Haryanto AR.,MS
Rois Fatoni, S.T., M.Sc., Ph.D

PROGRAM STUDI TEKNIK KIMIA FAKULTAS TEKNIK
UNIVERSITAS MUHAMMADIYAH SURAKARTA
SURAKARTA
2016

INTISARI

Prarancangan pabrik Alumunium sulfat bertujuan untuk memasok

kebutuhan Alumunium Sulfat secara domestik. Aluminium sulfat Al2(SO4)3 yang
lebih dikenal dengan tawas merupakan salah satu bahan kimia yang diperlukan
untuk pengolahan air di PDAM dan berbagai macam kegiatan industri. makanan
dan minuman.
Proses yang digunakan untuk pembentukan Alumunium Sulfat
menggunakan reaksi heterogen fase cair dan padat yang menghasilkan produk
samping Na2SO4, FeSO4 dan Fe. Proses reaksi berlangsung di dalam reaktor
CSTR/RATB. Reaksi terjadi pada suhu 90 0C dengan tekanan 1 atm selama 180
menit dengan konversi raksi didalam reaktor sebesar 85 %, reaksi ini bersifat
eksotermis dan berjalan searah. Produk alumunium sulfat yang dihasilkan
sebanyak 3.156.5656 kg/jam, untuk menghasilkan produk sesuai perhitungan,
maka dibutuhkan bahan baku asam sulfat sebanyak 4.747.003 kg/jam dan kaolin
sebanyak 1.646,9195 kg/jam. Unit pendukung proses (utilitas) meliputi
penyediaan air pendingin 18.539,8128 kg/jam, air untuk kebutuhan steam sebesar
540,8879 kg/jam yang di produksi dari boiler dengan bahan bakar solar sebesar
79,014 L/jam, air untuk sanitasi sebesar 2.099,0872 kg/jam. Pabrik alumunium
sulfat ini membutuhkan listrik sebesar 406,610 disediakan dari PLN dan
disediakan sebuah generator set sebagai cadangan. Kebutuhan udara tekan
sebesar 30 m3/jam. Pabrik ini direncanakan berdiri di Karawang, Jawa Barat pada
tahun 2020 dengan luas 23.780 m2 dengan jumlah karyawan sebanyak 158 orang.

Dari analisis ekonomi terhadap pabrik Alumunium Sulfat menunjukkan
keuntungan sebelum pajak Rp 90.900.115.811 per tahun setelah dipotong
pajakkeuntungan mencapai Rp 68.175.086.858. Percent Return On Investment
(ROI) sebelum pajak 38,77% dan setelah pajak 29,08%. Pay Out Time (POT)
sebelum pajak 2,05 tahun dan setelah pajak 2,56 tahun. Break Even Point (BEP)
sebesar 47,78% dan Shut Down Point (SDP) sebesar 27,97% dan Discounted
Cash Flow(DCF) terhitung sebesar 43,17%. Dari data analisis kelayakan di atas
disimpulkan, bahwa pabrik ini menguntungkan dan layak untuk didirikan.

Kata Kunci : Alumunium sulfat, Asam sulfat, CSTR/RATB

iv

ABSTRACT

Alumunium sulphate factory aims to supply alumunium Suphate needs
domestically. Alumunium sulphate Al2(SO4)3 known alum is one of the necessary
chemicals for water treatment in waterworks and a variety of industry events, food
an drinks.
The process used for the formation of alumunium sulphate using

heterogeneous phase reaction liquid and solid which produces a by product of
Na2SO4, FeSO4 and Fe. Reaction process taking place in the reactor CSTR/RATB.
The reaction occurs at a temperature of 90 OC whith pressure 1 atm for 180
minutes with conversion in reaction of 85%, it is an exothermic reaction an direct
running. Alumunium sulphate products are produced as much as 3.156,5656
kg/hour, to produce appropriate calculation then it takes as much sulfuric acid raw
materials 4.747,003 kg/hour and kaolin as much as 1.646,9195 kg/hour. The
supporting unit processes (utilities) include provision of water cooling
18.539,8128 kg/hour, water steam for the needs of 540,8879 kg/hour which in the
production of diesel fuel with boilers of 79,014 Liter/hour, water for sanitation of
2.099,0872 kg/hour. Aluminium sulphate factory needs electricity of 406,610 kW
provided from PLN and provided a generator set as a backup. Compressed air
requirement of 30 m3/hour. This factory is planned to stand at karawang, West
Java, by 2020 with the number of employess with 23.780 m2 as much as 158
people.
Economic analysis of alumunium sulphate factory demonstrated against a
profit before tax of Rp 90.900.115.811 per year after the cut profit reacher Rp
68.175.086.858. Return on Investment (ROI) before tax 38,77%, after tax 29,08%.
Pay Out Time (POT) before tax 2,05 years dan after tax 2,56 years. Break even
Point (BEP) of 47,78%, Shut Down Point (SDP) of 27,97% and Discounted Cash

Flow (DCF) accounting of 43,25%. Feasibility analysisi of the data above, it was
concluded that the factory is profitable and viable to set up.

Key word : Alumunium sulphate, Sulfuric acid, CSTR/RATB

v

MOTTO
“Sesungguhnya sesudah kesulitan itu ada kemudahan. Maka apabila kamu telah
selesai (dari suatu urusan) kerjakan dengan sungguh-sungguh (urusan) yang lain,
dan hanya kepada Tuhan mullah kamu berharap.”
(Q.S Asy-Syarh: 6-8)
“Allah akan meninggikian orang-orang beriman diantara mu dan orang-orang
yang diberi ilmu pengetahuan beberapa derajat”
(Q.S Al-Mujadalah: 11)
“If There is a will, there is away: Jika ada kemauan pasti ada jalan “

vi

PERSEMBAHAN

Segala puji syukur selalu tercurah kepada-Mu Yaa Allah atas segala nikmat dan
karunia-Mu penulis dapat menyelesaikan tugas akhir ini.
Tugas akhir ini saya persembahkan untuk:
1. Ibu,Bapak dan adik tercinta yang telah memberikan dukungan dan semangat
sehingga saya bisa menyelesaikan tugas akhir ini.
2. Partner saya Warih Nurtyasti, terima kasih telah menjadi partner TPP ku.
Terima kasih untuk kesabaran, persahabatan dan kerjasamanya untuk
menyelesaikan tugas akhir ini.
3. Keluarga besar Badan Eksekutif Mahasiswa Fakultas Teknik UMS dan
Dewan Perwakilan Mahasiswa Fakultas Teknik UMS yang sudah
memberikan banyak pengalaman, pelajaran, dan kenangan yang mendalam
untuk saya.
Temen-teman Teknik Kimia 2011 yang telah bersama-sama dalam perkuliahan
yang menyenangkan. Terimakasih atas doa dan semangat dari kalian semua.

vii

KATA PENGANTAR

Puji syukur penulis panjatkan kepada Allah SWT atas limpahan rahmat,
taufik dan hidayah-Nya sehingga penulis dapat menyelesaikan Tugas Akhir
dengan judul “Prarancangan Pabrik Alumunium Sulfat dari Asam Sulfat dan
Kaolin Kapasitas 25.000 Ton/Tahun”. Sholawat serta salam selalu penulis
haturkan kepada Nabi Besar Muhammad SAW yang kita nantikan syafa’atnya di
Yaumul Qiyamah nanti.
Tugas Prarancangan Pabrik merupakan salah satu syarat yang wajib
ditempuh untuk menyelesaikan program strata 1 di Program Studi Teknik Kimia,
Fakultas Teknik, Universitas Muhammadiyah Surakarta.
Pada kesempatan ini, penulis ucapkan terima kasih kepada pihak-pihak
yang

telah

memberikan

dukungan,

bimbingan,

dan

bantuan

hingga

terselesaikannya laporan tugas akhir ini. Adapun pihak-pihak tersebut, antara lain:
1. Ir. Haryanto AR,.MS sebagai dosen pembimbing I
2. Rois Fatoni, S.T., M.Sc., Ph.D sebagai dosen pembimbing II
3. Seluruh dosen dan staf Teknik Kimia Universitas Muhammadiyah Surakarta
4. Segenap civitas akademika dan teman-teman mahasiswa Teknik Kimia FT
UMS khususnya angkatan 2011.
Penulis berharap semoga laporan ini bermanfaat bagi semua pihak yang membaca.

Surakarta,

Agustus 2016

Penulis

viii

DAFTAR ISI
HALAMAN JUDUL ........................................................................................ i
HALAMAN PENGESAHAN ......................................................................... ii
HALAMAN KEASLIAN SKRIPSI ............................................................... iii
INTISARI ......................................................................................................... iv
MOTTO ............................................................................................................ vi
PERSEMBAHAN ............................................................................................ vii
KATA PENGANTAR ...................................................................................... viii
DAFTAR ISI .................................................................................................... ix
DAFTAR TABEL ............................................................................................ xiv
DAFTAR GAMBAR ....................................................................................... xvi
BAB I ................................................................................................................. 1
PENDAHULUAN ............................................................................................. 1
1.1 Latar Belakang Pendirian Pabrik ...................................................... 1
1.2 Kapasitas Pabrik ............................................................................... 2
1.3 Pemilihan Lokasi Pabrik .................................................................. 5
1.4 Tinjauan Pustaka .............................................................................. 7
1.4.1 Macam-macam Proses ............................................................. 7

1.4.2 Pemilihan Proses ...................................................................... 9
1.4.3 Kegunaan Produk ..................................................................... 10
1.4.4 Sifat Fisis dan Kimia ................................................................ 11
BAB II ............................................................................................................... 14
DESKRIPSI PROSES ...................................................................................... 14
2.1 Spesifikasi Bahan Baku dan Produk ................................................ 14
2.1.1 Spesifikasi Bahan Baku ............................................................. 14
2.1.2 Spesifikasi Bahan Tambahan .................................................... 14
2.1.3 Spesifikasi Produk ..................................................................... 15
2.2 Konsep Proses .................................................................................. 15
2.2.1 Dasar Proses ............................................................................. 15
2.2.2 Kondisi Operasi ........................................................................ 15
2.2.3 Tinjauan Termodinamika ......................................................... 15
2.2.4 Tinjauan Kinetika ..................................................................... 17

ix

2.3 Deskripsi Proses ............................................................................... 18
2.3.1 Langkah Proses ........................................................................ 19
2.3.2 Diagram Alir Proses ................................................................. 19

2.4 Neraca Massa dan Neraca Panas ...................................................... 22
2.4.1 Neraca Massa ........................................................................... 22
2.4.2 Neraca Panas ............................................................................ 26
2.5 Tata Letak Pabrik dan Peralatan ...................................................... 30
2.5.1 Tata Letak Pabrik ..................................................................... 30
2.5.2 Tata Letak Peralatan ................................................................. 34
BAB III ............................................................................................................. 36
SPESIFIKASI ALAT PROSES ....................................................................... 36
3.1 Belt Conveyor.................................................................................... 36
3.1.2 Belt Conveyor-01 ............................................................... 36
3.1.2 Belt Conveyor-02 .................................................................. 36
3.1.3 Belt Conveyor-03 ................................................................ 37
3.2 Blower ............................................................................................... 37
3.3 Bucket Elevator ................................................................................. 37
3.3.1 Bucket Elevator -01 .................................................................. 37
3.3.2 Bucket Elevator -02 .................................................................. 38
3.4 Centrifuge ......................................................................................... 38
3.4.1 Centrifuge-01 ............................................................................ 38
3.4.2 Centrifuge-02 ............................................................................ 39
3.5 Cooler ............................................................................................... 40

3.6 Filter ................................................................................................. 40
3.7 Gudang .............................................................................................. 41
3.7.1 Gudang Al2O3............................................................................ 41
3.7.2 Gudang Al2(SO4)3.18H2O ......................................................... 41
3.8 Heater ............................................................................................... 42
3.8.1 Heater-01 .................................................................................. 42
3.8.2 Heater-02 .................................................................................. 42
3.9 Hopper .............................................................................................. 43
3.10 Kristalizer ........................................................................................ 43
3.11 Pompa ............................................................................................. 44
3.11.1 Pompa-01 ................................................................................ 44
x

3.11.2 Pompa-02 ................................................................................ 44
3.11.3 Pompa-03 ................................................................................ 45
3.11.4 Pompa-04 ................................................................................ 46
3.11.5 Pompa-05 ................................................................................ 46
3.11.6 Pompa-06 ................................................................................ 47
3.11.7 Pompa-07 ................................................................................ 48
3.12 Reaktor ............................................................................................ 48
3.12.1 Reaktor-01 ............................................................................... 48
3.12.2 Reaktor-02 ............................................................................... 49
3.13 Rotary Dryer ................................................................................... 50
3.14 Silo .................................................................................................. 51
3.15 Tangki Penyimpanan ...................................................................... 51
BAB IV ............................................................................................................... 53
UNIT PENDUKUNG PROSES DAN LABORATORIUM .......................... 53
4.1 Unit Pendukung Proses ..................................................................... 53
4.1.1 Unit Penyediaan air dan Pengoahan air ................................... 54
4.1.2 Unit Penyediaan Steam ............................................................ 66
4.1.3 Unit Penyediaan Listrik............................................................. 68
4.1.4 Unit Penyediaan Bahan Bakar .................................................. 74
4.1.5 Unit Penyediaan Limbah ........................................................... 84
4.1.6 Unit Penyediaan Tekanan Udara ............................................... 85
4.2 Laboratorium..................................................................................... 86
4.2.1 Laboratorium Fisik ................................................................... 87
4.2.2 Laboratorium Analitik .............................................................. 87
4.2.3 laboratorium Penelitian dan Pengembangan ............................ 87
4.2.4 Analisis Air .............................................................................. 87
4.2.5 Analisa Sampel ......................................................................... 88
BAB V ............................................................................................................... 89
MANAJEMEN PERUSAHAAN ..................................................................... 89
5.1 Bentuk Perusahaan .......................................................................... 89
5.2 Struktur Organisasi ......................................................................... 90
5.3 Tugas dan Wewenang ..................................................................... 93
5.3.1 Pemegang Saham ...................................................................... 93
5..3.2 Direktur Utama......................................................................... 93
xi

5.3.3 Staf Ahli .................................................................................... 94
5.3.4 Kepala Bagian ........................................................................... 94
5.3.5 Kepala Seksi .............................................................................. 97
5.4 Pembagian Jam Kerja Karyawan ...................................................... 97
5.4.1 Karyawan Non Shift .................................................................. 97
5.4.2 Karyawan Shift.......................................................................... 98
5.5 Sistem Kepegawaian dan Upah ........................................................ 99
5.6 Penggolongan Jabatan, Jumlah Karyawan dan Gaji ......................... 100
5.6.1 Pengelolaan Jabatan .................................................................. 100
5.6.2 Jumlah Karyawan dan Gaji ....................................................... 100
5.7 Kesejahteraan Sosial Karyawan ........................................................ 101
5.8 Kesehatan dan Keselamatan Kerja.................................................... 102
5.9 Manajemen Produksi ........................................................................ 103
5.9.1 Perencanaan Produksi ............................................................... 103
5.9.2 Pengendalian Produksi .............................................................. 104
BAB VI .............................................................................................................. 106
ANALISIS EKONOMI .................................................................................... 106
6.1 Dasar Perhitungan ............................................................................. 106
6.2 Perhitungan Biaya ............................................................................. 109
6.2.1 Investasi Modal (Capital Investment) ....................................... 109
6.2.2 Biaya Produksi (Manufacturing Cost) ...................................... 109
6.2.3 Pegeluaran Umum (General Expenses) .................................... 109
6.3 Analisis Kelayakan ........................................................................... 110
6.3.1 Percent Return On Investment (ROI) ........................................ 110
6.3.2 Pay Out Time (POT) ................................................................. 110
6.3.3 Break Even Point (BEP)............................................................ 110
6.3.4 Shut Down Point (SDP) ............................................................ 111
6.3.5 Discounted Cash Flow .............................................................. 111
6.4 Hasil Perhitungan .............................................................................. 111
6.4.1 Total Fixed Capital Investment ................................................. 111
6..4.2 Working Capital ....................................................................... 112
6.4.3 Total Capital Investment (TCI) ................................................. 112
6.4.4 Direct Manufacturing Cost ........................................................ 112
6.4.5 Indirect Manufacturing Cost ..................................................... 113
xii

6.4.6 Fixed Manufacturing Cost......................................................... 113
6.4.7 Total Manufacturing Cost (TMC) ............................................. 113
6.4.8 General Expenses ...................................................................... 114
6.4.9 Total Production Cost (TPC) .................................................... 114
6.4.10 Perhitungan Keuntungan Produksi .......................................... 114
6.4.11 Analisis Kelayakan.................................................................. 115
6.5 Kesimpulan ....................................................................................... 120
DAFTAR PUSTAKA........................................................................................ 122
LAMPIRAN ...................................................................................................... 124

xiii

DAFTAR TABEL
Tabel 1.1 Data ekspor dan impor aluminium sulfat ........................................... 2
Tabel 1.2 Data kapasitas produksi pabrik alumunium sulfat di Indonesia ......... 4
Tabel 1.3 Data kapasitas produksi pabrik aluminium sulfat di dunia................. 4
Tabel 1.4 Perbandingan proses pembuatan aluminium sulfat ............................ 10
Tabel 2.1 Harga ΔHf° dan ΔGf° ......................................................................... 16
Tabel 2.2 Neraca massa pada reaktor-01 ............................................................ 22
Tabel 2.3 Neraca massa pada reaktor-02 ............................................................ 23
Tabel 2.4 Neraca massa pada centrifuge-01 ....................................................... 23
Tabel 2.5 Neraca massa pada kristaliser ............................................................ 24
Tabel 2.6 Neraca massa pada centrifuge-02 ...................................................... 24
Tabel 2.7 Neraca massa pada rotary dryer ......................................................... 25
Tabel 2.8 Neraca massa total setelah recycle ..................................................... 25
Tabel 2.9 Neraca panas heater-01 ...................................................................... 26
Tabel 2.10 Neraca panas pada reaktor-01 .......................................................... 26
Tabel 2.11 Neraca panas pada reaktor-02 .......................................................... 27
Tabel 2.12 Neraca panas pada centrifuge-01 ...................................................... 27
Tabel 2.13 Neraca panas pada cooler ................................................................. 28
Tabel 2.14 Neraca panas pada kristalizer ........................................................... 28
Tabel 2.15 Neraca panas pada centrifuge-02 ...................................................... 29
Tabel 2.16 Neraca panas pada rotary dryer........................................................ 29
Tabel 2.17 Neraca panas pada heater-02 ............................................................ 30
Tabel 2.18 Perincian luas tanah bangunan pabrik .............................................. 32
Tabel 4.1 Data kebutuhan air pendingin ........................................................... 64
Tabel 4.2 Data kebutuhan steam ........................................................................ 64
Tabel 4.3 Data kebutuhan air sanitasi ................................................................ 65
Tabel 4.4 Kebutuhan air total ............................................................................ 66
Tabel 4.5 Data kebutuhan listrik untuk proses .................................................. 69
Tabel 4.6 Data kebutuhan listrik untuk utilitas .................................................. 70
Tabel 4.7 Data kebutuhan listrik untuk penerangan ........................................... 72
Tabel 4.8 Data kebutuhan listrik total ................................................................ 73
Tabel 5.1 Jadwal kerja kelompok shift .............................................................. 99

xiv

Tabel 5.2 Penggolongan jabatan, jumlah karyawan dan gaji ............................ 100
Tabel 6.1 Cost index chemical plant................................................................... 107
Tabel 6.2 Total fixed capital investment ............................................................. 111
Tabel 6.3Working capital investment ................................................................. 112
Tabel 6.4 Total capital investment...................................................................... 112
Tabel 6.5 Direct manufacturing cost .................................................................. 112
Tabel 6.6 Indirect manufacturing cost................................................................ 113
Tabel 6.7 Fixed manufacturing cost ................................................................... 113
Tabel 6.8 Total anufacturing cost ....................................................................... 113
Tabel 6.9 General expenses ................................................................................ 114
Tabel 6.10 Total production ............................................................................... 114
Tabel 6.11 Fixed cost .......................................................................................... 116
Tabel 6.12 Variable cost ..................................................................................... 117
Tabel 6.13 Regulated cost................................................................................... 117
Tabel 6.14 Analisa kelayakan ............................................................................ 119

xv

DAFTAR GAMBAR
Gambar 1.1Hubungan aluminium sulfat dengan tahun ekspor .......................... 3
Gambar 1.2 Hubungan aluminium sulfat dengan tahun impor .......................... 3
Gambar 2.1 Diagram alir kualititatif prarancangan pabrik aluminium sulfat ... 20
Gambar 2.2 Diagram alir kuantitatif prarancangan pabrik aluminium sulfat .... 21
Gambar 2.3 Tata letak prarancangan pabrik aluminium sulfat .......................... 33
Gambar 2.4 Tata letak peralatan proses pabrik aluminium sulfat ..................... 35
Gambar 4.1 Denah utilitas prarancangan pabrik aluminium sulfat ................... 58
Gambar 5.1 Susunan struktur organisasi perusahaan ........................................ 92
Gambar 6.1 Hubungan tahun dengan cost index ............................................... 108
Gambar 6.2 Analisis kelayakan ekonomi pabrik aluminium sulfat ................... 119
Gambar 6.3 Cash Flow pabrik aluminium sulfat ............................................... 120

xvi