Analisa Risiko Kebakaran Proses Gas Liquefaction

Muradi, Munir (2015) Analisa Risiko Kebakaran Proses Gas Liquefaction. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Potensi gas bumi yang dimiliki Indonesia berdasarkan status tahun 2008 mencapai 170
Triliun Spesific Cubic Feet (TSCF) dan lokasi jauh dari daratan, sehingga untuk
mengamankan aset tersebut pemerintah Indonesia merencanakan sebuah bangunan
lepas pantai yang mampu melakukan exploitasi dengan aman dan ekonomis, maka
Floating Liquefied Natural Gas (FLNG) merupakan sebuah pilihan tepat. Namun
instalasi tersebut merupakan sebuah teknologi instalasi lepas pantai yang sangat
kompleks, sehingga dibutuhkan sebuah analisa yang tepat dalam memelihara
keberlangsungan proses pengelolaan gas tersebut dengan aman. Terlebih pada proses
liquefaction unit yang kondisi gasnya masih sangat rentan untuk terjadinya kebakaran
yang ditimbulkan oleh gas release dan jenis pendingin yang digunakan adalah
termasuk jenis chemical yang mudah terbakar. Untuk itu perlu dilakukan analisa risiko
terhadap sistem tersebut. Metode penilaian risiko dilakukan berdasarkan peraturan Risk
Assessment Applications for The Marine and Offshore OIL and Gas Industries. Dimana
hazard identifikasi dilakukan dengan menggunakan HAZard Operability (HAZOP),
analisa frekuensi gas release dengan menggunakan Fault Tree Analysis (FTA). Dari
nilai tersebut ditentukan frekuensi terjadinya kemungkinan akibat dari gas release
seperti Jet Fire, Flash Fire, Gas Explosion dan Gas Dispersion dengan menggunakan
Event Tree Analisys (ETA). Selanjutnya dilakukan analisa Konsekuensi dengan
menggunakan software ALOHA. Berdasarkan hasil analisis frequency dan
consequences, maka tingkat risiko direpresentasikan dengan menggunakan f-N curve
yang mengacu pada standard UK Offshore 1991 diperoleh hasil bahwa potensi yang
ditimbulkan oleh jenis risiko jet fire untuk hole 50 mm berada pada kondisi (As Low As
Reasonably Practicable) ALARP, Dimana kondisi ini masih berada pada kondisi risiko
yang aman, namun bisa juga dilakukan mitigasi, salah satu langkah mitigasi yang
dilakukan yaitu menambah komponen pengaman untuk mencegah terjadinya
overpressure pada pipa serta menambah alat keselamatan para pekerja. Sedangkan
untuk diameter kebocoran 100 mm dan 200 mm berada pada kondisi Acceptable
artinya risiko berada pada kondisi dapat diterima. Untuk konsekuensi gas explosion
kemungkinan terjadinya sangat kecil dengan nilai frekuensinya <10-6. Dan konsekuensi
gas dispersion tidak dapat mengakibatkan efek beracun pada manusia karena gas yang
terilis berada dibawah 50,000 ppm.
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The potential amount of natural gas owned by Indonesia, based on the data in 2008,
reached 170 Trillion Specific Cubic Feet (TSCF) and it is located far away from the
mainland. To secure this asset, the Government of Indonesia planned to build an offshore
facility to be able to exploit it safely and economically, which is why the Floating
Liquefied Natural Gas (FLNG) became an ideal option. However, FLNG is an offshore
installation with a complex technology, so a proper analysis to maintain the continuity of
the process gas safety management is a necessity. This becomes very important especially
in the liquefaction unit process that is very vulnerable to fire due to gas release and
inflammable type of chemical refrigerant. Therefore, risk assessment on the system must
be conducted. The method of risk assessment conducted complied with the Risk
Assessment Applications for The Marine and Offshore Oil and Gas Industries, in which
hazard identification was carried out using Hazard Operability (HAZOP) and the
analysis of gas release frequency was performed using Fault Tree Analysis (FTA). The
results of these analyses were used to run Event Tree Analysis (ETA) to find out the
possible frequency of gas release related cases, such as Jet Fire, Flash Fire, Gas
Explosion, and Gas Dispersion. After that, consequences analysis was conducted using
ALOHA software. Frequency and consequences analyses showed a level of risk indicated
with f-N curve, referring to UK Offshore 1991. The results revealed that the chance for a
jet fire to take place with a 50 mm hole is considered ALARP (As Low As Reasonably
Practicable), which means that this is a safe condition but mitigations can still be carried
out. Some of the possible mitigations that can be done are to add safety components to
prevent overpressure in the pipe and provide additional safety equipment for workers.
Furthermore, a leak with a diameter of 100 mm and 200 mm is considered acceptable,
which means that the risk is on an acceptable level. The possibility of gas explosion to
take place is also very low with a frequency value <10-6 and gas dispersion will not have
a hazardous effect on human since the released gas is under 50,000 ppm.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Risk Assessment, FLNG, Fire Modeling, Representasi Risiko
Subjects: V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering
Divisions: Faculty of Marine Technology (MARTECH) > Marine Engineering > 36101-(S2) Master Theses
Depositing User: Mr. Fandika aqsa
Date Deposited: 22 Jun 2017 02:14
Last Modified: 22 Jun 2017 02:14
URI: http://repository.its.ac.id/id/eprint/41808

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