i

TUGAS AKHIR

PRARANCANGAN PABRIK ASAM NITRAT

DARI ASAM SULFAT DAN NATRIUM NITRAT

KAPASITAS 65.000 TON PER TAHUN

HALAMAN JUDUL

Diajukan Guna Melengkapi Persyaratan dalam Menyelesaikan Pendidikan

Tingkat Strata Satu di Jurusan Teknik Kimia Fakultas Teknik

Universitas Muhammadiyah Surakarta

Oleh:

Luluk Pratiwi

D 500 120 070

Dosen Pembimbing:

M. Mujiburohman, Ph.D.

Hamid Abdillah, S.T., M.T.

PROGRAM STUDI TEKNIK KIMIA FAKULTAS TEKNIK

UNIVERSITAS MUHAMMADIYAH SURAKARTA

SURAKARTA

2016

v

KATA PENGANTAR

Puji syukurkepada Allah SWT, karena atas rahmat dan karunia-Nya

penulis akhirnya dapat menyelesaikantugas prarancangan pabrik asam nitrat dari

asam sulfat dan natrium nitrat kapasitas 65.000 ton/tahun.

Laporan ini dibuat untuk memenuhi mata kuliah tugas prarancangan

pabrik. Tugas prarancangan pabrik merupakan syarat kelulusan bagi mahasiswa

tahap sarjana di Jurusan Teknik Kimia, Fakultas Teknik, Universitas

Muhammadiyah Surakarta. Dalam penyusunan laporan ini penulis banyak

mendapat bimbingan, dorongan dan motivasi dari berbagai pihak. Untuk itu, kami

ingin mengucapkan terima kasih kepada:

1. Orang tua dan keluarga yang selalu memberikan dukungan dan doa sehingga

tugas prarancangan pabrik ini selesai.

2. Bapak Rois Fatoni, S.T., M.Sc., Ph.D., selaku Ketua Jurusan Teknik Kimia

FT-UMS.

3. Bapak M. Mujiburohman Ph.D., selaku pembimbing I atas bimbingan,

bantuan dan perhatiannya.

4. Bapak Hamid Abdillah, S.T., M.T., selaku dosen pembimbing II atas

bimbingan, bantuan dan perhatiannya.

5. Rizki Dyah Arimurti partner tugas prarancangan pabrik yang telah membantu

dan mendukung dalam segala hal.

6. Fernanto, Andayani, Hendra, Ifur, Edo sebagai partnerdan sahabat-sahabat

yang luar biasa.

7. Semua pihak yang membantu dalam penyusunan tugas prarancangan pabrik

ini.

Penulis menyadari bahwa tugas prarancangan pabrik ini masih ada

kekurangan, karena itu kami mengharapkan segala kritik dan saran yang

membangun. Semoga tugas prarancangan pabrik yang kami laksanakan ini dapat

bermanfaat khususnya di bidang teknik kimia dan aplikasi di industri kimia.

Surakarta, Oktober 2016

Penulis

vi

DAFTAR ISI

HALAMAN JUDUL ................................................................................................ i

HALAMAN PENGESAHAN ................................................................................ iii

PERNYATAAN KEASLIAN SKRIPSI ................................................................ iv

KATA PENGANTAR ............................................................................................. v

DAFTAR ISI .......................................................................................................... vi

DAFTAR TABEL .................................................................................................. xi

DAFTAR GAMBAR ........................................................................................... xiii

INTISARI ............................................................................................................. xiv

BAB I PENDAHULUAN ..................................................................................... 1

1.1 Latar Belakang Pendirian Pabrik....................................................... 1

1.2 Kapasitas Pabrik ................................................................................ 1

1.3 Pemilihan Lokasi Pabrik ................................................................... 2

1.4 Tinjauan Pustaka ............................................................................... 5

1.4.1 Pemilihan Proses .................................................................... 5

1.4.2 Kegunaan Produk ................................................................... 6

1.4.3 Sifat Fisik dan Kimia Bahan Baku dan Produk ........................ 7

1.4.4 Tinjauan Proses Secara Umum ............................................... 9

BAB II DESKRIPSI PROSES ............................................................................. 10

2.1 Spesifikasi Bahan Baku dan Produk ............................................... 10

2.1.1 Spesifikasi Bahan Baku ........................................................ 10

2.1.2 Spesifikasi Produk ................................................................ 10

2.2 Konsep Reaksi ................................................................................. 11

2.2.1 Dasar Reaksi ......................................................................... 11

2.2.2 Kondisi Operasi .................................................................... 11

2.2.3 Tinjauan Termodinamika ...................................................... 11

2.2.4 Tinjauan Kinetika .................................................................. 13

2.3 Deskripsi Proses .............................................................................. 13

2.4 Neraca Massa .................................................................................. 15

2.5 Neraca Panas ................................................................................... 17

vii

b. Diagram Alir Proses dan Material ................................................... 22

2.7 Tata Letak Peralatan ........................................................................ 24

2.7.1 Tata Letak Pabrik .................................................................. 24

2.7.2 Tata Letak Proses .................................................................. 28

BAB III SPESIFIKASI ALAT PROSES .............................................................. 31

3.1 Reaktor ............................................................................................ 31

3.2 Separator.......................................................................................... 31

3.3 Absorber .......................................................................................... 32

3.4 Menara Distilasi .............................................................................. 33

3.5 Tangki.............................................................................................. 34

3.5.1 Tangki-110 ............................................................................ 34

3.5.2 Tangki-111 ............................................................................ 35

3.5.3 Tangki-112 ............................................................................ 36

3.5.4 Tangki-113 ............................................................................ 37

3.6 Belt Conveyor .................................................................................. 38

3.7 Bucket Elevator ............................................................................... 38

3.8 Hopper ............................................................................................. 39

3.9 Blower ............................................................................................. 39

3.10 Heater .............................................................................................. 40

3.10.1 Heater-110 .......................................................................... 40

3.10.2 Heater-111 .......................................................................... 40

3.11 Condensor ....................................................................................... 41

3.11.1 Condensor-120 .................................................................... 41

3.11.2 Condensor-121 .................................................................... 42

3.12 Cooler .............................................................................................. 42

3.12.1 Cooler-130 .......................................................................... 42

3.12.2 Cooler-131 .......................................................................... 43

3.12.3 Cooler-132 .......................................................................... 44

3.13 Reboiler ........................................................................................... 44

3.14 Accumulator .................................................................................... 45

3.15 Mixer ............................................................................................... 46

viii

3.16 Pompa .............................................................................................. 46

3.16.1 Pompa-110 .......................................................................... 46

3.16.2 Pompa-111 .......................................................................... 47

3.16.3 Pompa-112 .......................................................................... 48

3.16.4 Pompa-113 .......................................................................... 48

3.16.5 Pompa-114 .......................................................................... 49

3.16.6 Pompa-115 .......................................................................... 50

3.16.7 Pompa-116 .......................................................................... 50

3.16.8 Pompa-117 .......................................................................... 51

3.16.9 Pompa-118 .......................................................................... 52

BAB IV UNIT PENDUKUNG PROSES (UTILITAS) DAN

LABORATORIUM ................................................................................. 53

4.1 Unit Pendukung Proses (Utilitas) .................................................... 53

4.1.1 Unit Pendukung Proses (Utilitas) .......................................... 54

4.1.2 Unit Penyediaan Steam ......................................................... 65

4.1.3 Unit Penyediaan Listrik ........................................................ 65

4.1.4 Unit Penyediaan Bahan Bakar .............................................. 68

4.1.5 Spesifikasi Alat Utilitas ........................................................ 69

4.1.6 Unit Pengolahan Limbah ...................................................... 77

4.1.7 Unit Penyediaan Udara Tekan .............................................. 78

4.2 Laboratorium ................................................................................... 79

4.2.1 Laboratorium Fisik ................................................................ 80

4.2.2 Laboratorium Analitik .......................................................... 80

4.2.3 Laboratorium Penelitian dan Pengembangan ....................... 80

4.2.4 Analisis Air ........................................................................... 80

4.2.5 Analisis Sampel .................................................................... 81

BAB V MANAJEMEN PERUSAHAAN ............................................................ 82

5.1 Bentuk Perusahaan .......................................................................... 82

5.2 Struktur Organisasi .......................................................................... 83

5.3 Tugas dan Wewenang ..................................................................... 86

5.3.1 Pemegang Saham .................................................................. 86

ix

5.3.2 Direktur Utama ..................................................................... 86

5.3.3 Staff Ahli ............................................................................... 87

5.3.4 Kepala Bagian ....................................................................... 87

5.3.5 Kepala Seksi .......................................................................... 90

5.4 Pembagian Jam Kerja Karyawan .................................................... 90

5.4.1 Karyawan Non Shift .............................................................. 90

5.4.2 Karyawan Shift ...................................................................... 91

5.5 Kepegawaian dan Sistem Upah ....................................................... 92

5.6 Penggolongan Jabatan, Jumlah Karyawan, dan Gaji ...................... 93

5.6.1 Penggolongan Jabatan ........................................................... 93

5.6.2 Jumlah Karyawan dan Gaji ................................................... 93

5.7 Kesejahteraan Sosial Karyawan ...................................................... 94

5.8 Kesehatan dan Keselamatan Kerja .................................................. 95

5.9 Manajemen Produksi ....................................................................... 95

5.9.1 Perencanaan Produksi ........................................................... 96

5.9.2 Pengendalian produksi .......................................................... 97

BAB VI ANALISIS EKONOMI ........................................................................... 98

6.1 Dasar Perhitungan ........................................................................... 98

6.2 Perhitungan Biaya ......................................................................... 101

6.2.1 Investasi Modal (Capital Invesment) .................................. 101

6.2.2 Biaya Produksi (Manufacturing Cost) ................................ 101

6.2.3 Pengeluaran Umum (General Expenses) ............................ 101

6.3 Analisis Kelayakan ........................................................................ 102

6.3.1 Percent Return On Investment (ROI) .................................. 102

6.3.2 Pay Out Time (POT) ........................................................... 102

6.3.3 Break Event Point (BEP) .................................................... 103

6.3.4 Shut Down Point (SDP) ...................................................... 103

6.3.5 Internal Rate Of Return (IRR) ............................................. 103

6.4 Hasil Perhitungan .......................................................................... 104

6.4.1 Total Fixed Capital Investment ........................................... 104

6.4.2 Working Capital .................................................................. 104

x

6.4.3 Total Capital Investment ..................................................... 104

6.4.4 Direct Manufacturing Cost ................................................. 105

6.4.5 Indirect Manufacturing Cost ............................................... 105

6.4.6 Fixed Manufacturing Cost .................................................. 105

6.4.7 Total Manufacturing Cost ................................................... 106

6.4.8 General Expense ................................................................. 106

6.4.9 Total Production Cost ......................................................... 106

6.4.10 Perhitungan Keuntungan Produksi .................................... 106

6.5 Analisis Kelayakan ........................................................................ 107

6.6 Kesimpulan.................................................................................... 112

DAFTAR PUSTAKA .......................................................................................... 113

LAMPIRAN ......................................................................................................... 115

xi

DAFTAR TABEL

Tabel 1.1 Data impor perdagangan asam nitrat ...................................................... 2

Tabel 1.2 Kapasitas produksi pabrik asam nitrat di dunia ...................................... 2

Tabel 2.1 Harga ∆Ho

F298dan∆Go

F298 ..................................................................... 12

Tabel 2.2 Neraca massa di reaktor ........................................................................ 15

Tabel 2.3 Neraca massa di kondensor ................................................................... 16

Tabel 2.4 Neraca massa di separator ..................................................................... 16

Tabel 2.5 Neraca massa di absorber ...................................................................... 16

Tabel 2.6 Neraca massa di mixer .......................................................................... 16

Tabel 2.7 Neraca massa di menara distilasi .......................................................... 17

Tabel 2.8 Neraca massa overall pabrik asam nitrat asam sulfat dan natrium

nitrat ...................................................................................................... 17

Tabel 2.9 Data heat capacity of gas masing-masing komponen ........................... 17

Tabel 2.10 Data heat capacity of liquid masing-masing komponen ..................... 18

Tabel 2.11 Neraca panas di heater ........................................................................ 18

Tabel 2.12 Neraca panas di reaktor ....................................................................... 19

Tabel 2.13 Neraca panas di kondensor ................................................................. 19

Tabel 2.14 Neraca panas di separator ................................................................... 19

Tabel 2.15 Neraca panas di cooler ........................................................................ 20

Tabel 2.16 Neraca panas di cooler ........................................................................ 20

Tabel 2.17 Neraca panas di absorber .................................................................... 20

Tabel 2.18 Neraca panas di menara distilasi ......................................................... 21

Tabel 2.19 Luas bangunan pabrik ......................................................................... 26

Tabel 4.1 Daftar kebutuhan air pendingin............................................................. 64

Tabel 4.2 Daftar kebutuhan air steam ................................................................... 64

Tabel 4.5 Kebutuhan listrik proses........................................................................ 66

Tabel 4.6 Kebutuhan listrik utilitas ....................................................................... 67

Tabel 4.7 Kebutuhan listrik total ............................................................................ 68

Tabel 5.1 Jadwal kerja kelompok shift ................................................................... 94

Tabel 5.2 Penggolongan jabatan, jumlah karyawan dan gaji ................................ 93

xii

Tabel 6.1 Cost index chemical plant ..................................................................... 99

Tabel 6.2 Total fixed capital investment ............................................................. 104

Tabel 6.3 Total working capital .......................................................................... 104

Tabel 6.4 Total capital investment ...................................................................... 104

Tabel 6.5 Total direct manufacturing cost .......................................................... 105

Tabel 6.6 Total indirect manufacturing cost ....................................................... 105

Tabel 6.7 Total fixed manufacturing cost ........................................................... 105

Tabel 6.8 Total manufacturing cost .................................................................... 106

Tabel 6.9 Total general expense ......................................................................... 106

Tabel 6.10 Total production cost ........................................................................ 106

Tabel 6.11 Fixed cost .......................................................................................... 108

Tabel 6.12 Variable cost ..................................................................................... 109

Tabel 6.13 Regulated cost ................................................................................... 109

Tabel 6.14 Analisis kelayakan ............................................................................ 111

xiii

DAFTAR GAMBAR

Gambar 2.1. Diagram alir kualitatif pabrik asam nitrat dari asam sulfat dan

natrium nitrat kapasitas 65.000 ton/tahun ....................................... 22

Gambar 2.2. Diagram alir kuantitatif pabrik asam nitrat dari asam sulfat dan

natrium nitrat kapasitas 65.000 ton/tahun ........................................ 23

Gambar 2.3 Tata letak pabrik asam nitrat ............................................................. 27

Gambar 2.4. Tata letak peralatan proses pabrik asam nitrat dari asam sulfat

dan natrium nitrat .............................................................................. 30

Gambar 4.1 Denah utilitas prarancangan pabrik asam nitrat ................................ 58

Gambar 5.1 Struktur organisasi perusahaan ......................................................... 85

Gambar 6.1 Hubungan tahun dengan cost index ............................................... 100

xiv

INTISARI

Pabrik asam nitrat dari asam sulfat dan natrium nitrat dengan kapasitas

65.000 ton/tahun direncanakan berdiri pada tahun 2020 di Karawang, Jawa Barat.

Bahan baku natrium nitrat diimpor dari Chili, dan asam sulfat dari PT Indonesian

Acid Industry. Proses pembuatan asam nitrat menggunakan Reaktor Alir Tangki

Berpengaduk (RATB). Reaksi pembentukan asam nitrat berlangsung pada kondisi

eksotermis, non adiabatic dengan pendingin berupa jaket, reaksi berjalan secara

irreversible, beroperasi pada suhu 150°C dan tekanan 1 atm. Pabrik ini tergolong

pabrik berisiko rendah karena kondisi operasi atmosferis.

Reaksi pembentukan asam nitrat diawali dengan mereaksikan asam sulfat

dan natrium nitrat dalam reactor (R-110). Produk keluar dari reactor berupa gas

diembunkan dalam kondensor kemudian dimurnikan di dalam menara distilasi

untuk menghasilkan produk dengan kemurnian 98%, sedangkan hasil bawah

reactor berupa campuran asam nitrat, natrium nitrat, dan natrium bisulfate (niter

cake). Produk asam nitrat yang dihasilkan sebesar 8.207,0707 kg/jam. Unit

pendukung proses terdiri dari unit penyedia air pendingin sebesar 264.779,2772

kg/jam, kebutuhan steam sebesar 19.772,5449 kg/jam, dan kebutuhan air sanitasi

sebesar 1.288,3656 kg/jam. Kebutuhan air diperoleh dari air sungai Kalimalang,

sedangkan kebutuhan listrik dipenuhi dari PLN dan generator set sebagai

cadangan apabila PLN mengalami gangguan.

Hasil analisis ekonomi pabrik asam nitrat diperoleh keuntungan sebelum

pajak sebesar Rp113.168.435.407 per tahun, keuntungan setelah pajak sebesar

Rp84.876.326.556. Percent return on investment (ROI) sebelum pajak 34,52%

dan setelah pajak 25,89%. Pay out time (POT) sebelum pajak 2,25 tahun dan

setelah pajak 2,79 tahun. Break event point (BEP) sebesar 47,80%, Shut Down

Point (SDP) sebesar 25,11%, dan Internal Rate of Return (IRR) sebesar 40,27%.

Dari data analisis kelayakan di atas disimpulkan bahwa pabrik ini layak untuk

didirikan.

Kata kunci: Asam nitrat, asam sulfat, niter cake, RATB

xv

ABSTRACT

Nitric acid plant with raw materials of sulphuric acid and sodium nitrate

with a capacity 65.000 tons/year is planned to be established in 2020 in

Karawang, West Java. The sodium nitrate is imported from Chile and the

sulphuric acid is from PT Indonesian Acid Industry. The nitric acid production

uses continuous stirred tank reactor (CSTR). The reaction is exothermic, non

adiabatic, and irreversible, carried out at temperature of 150°C and pressure of 1

atm. The plant is categorized as low risk process due to the friendly operating

conditions.

The process of nitric acid production is initiated with reacting sulphuric

acid and sodium nitrate in the reactor. The vapor product of reactor is condensed

by a partial condenser and is purified in distillation tower to produce nitric acid

with purity of 98%, while the liquid product, called niter cake, is stored as side

product. Based on the capacity, the production of nitric acid is 8,207.0707

kgs/hour. To support the process, utilities are required including 264,779.5449

kgs/hour of cooling water, 19,772.5449 kgs/hour of steam. Which is obtained from

boiler consuming fuel oil as much as 1,473.8109 L/hour, and electricity supplied

from PLN and generator set. The water source is taken from Kalimalang river,.

The economic analysis gives the profit before tax is

Rp113,168,435,407/year, and Rp84,876,326,556/year after tax. The percent

Return on Investment (ROI) before tax is 34.52% and 25.89% after tax. The Pay

Out Time (POT) before tax is 2.25 years and 2.79 years after tax. The Break

Event Point (BEP), the Shut Down Point (SDP), and the Internal Rate of Return

(IRR) are 47.80, 25.11%, and 40.27%, respectively. The above economic analysis

concludes that the plant is feasible to set.

Keyword: CSTR, niter cake, nitric acid, sulphuric acid