Risk and Economical Assessment LNG Fuel System Design in Dual-Fuel Engine Conversion on Crude Oil Tanker

The shipping industry, both international and domestic, is one of the largest emitters in the world. IMO has made various efforts to reduce the number of emissions the shipping industry generates. MARPOL Annex VI IMO issued a new regulation to reduce the number of emissions from ships. Replacing ship fuel oil with natural gas is one alternative that can substantially reduce the emission produced by ships. Natural gas can reduce CO₂ limits by 25-30%, reduce SOx and solid particulate matter (PM) by 100%, and NOx can be reduced by up to 90%. Some have questioned the safety and economic prospects of using natural gas as fuel on ships. Therefore, risk and economic analyses were carried out in this study on converting 63000 GT crude oil tankers into dual-fuel LNG. Converting ship fuel from HFO to LNG means a new design for the fuel system, the P&ID of the LNG fuel system will be designed and analyzed for the fire explosion risks and the economics of the conversion project. The ship's LNG fuel system P&ID design will be carried out using software engineering drawings. The risks will be analyzed using Hazard Operability (HAZOP) from the design. After determining the potential hazard, a quantitative risk analysis using frequency and consequence analysis was conducted. Fault Tree Analysis and Event Tree Analysis methods analyze the frequency of hazards that may arise. The potential hazard will be mapped using modeling software (ALOHA) to determine the impact and consequences that arise from the hazard. The results of this risk analysis will be mapped on the F-N Curve to see each system's risk level. Economic analysis was carried out to determine the length of time the initial investment cost for converting the ship. In the analysis stage, the risk of the fuel system is divided into six nodes. After a frequency analysis, it found that the largest fires in the system are LNG regasification pump with a failure frequency of 4.08.E-03 per year with a Jet Fire, Explosion, and Flash Fire frequency of 8.15.E-04 each, 1.30.E-04; 9.78.E-05. All risks are mapped on the F-N curve, showing that all risk levels are acceptable. For economic analysis calculations on LNG conversion projects, the Capital Recovery Factor (CRF) method determines the return on investment from crude oil tanker conversion projects with ROI obtained for four years with an inflation assumption of 10%.