Techno-economic assessment of liquefied hydrogen tanker ships utilizing various propulsion systems

Abstract

Efficient and sustainable hydrogen transportation is essential for realizing the hydrogen economy. This study investigates the economic and environmental impacts of various fuel and propulsion systems: internal combustion engine (ICE) using heavy fuel oil (HFO), liquefied natural gas (LNG), hydrogen (H₂), ammonia (NH₃), and solid oxide fuel cell (SOFC), across two shipping routes for transporting hydrogen from Australia to South Korea and Singapore. The main analysis includes the levelized cost of hydrogen transportation (LCOHT), carbon dioxide (CO₂) emissions, and net present value (NPV). ICE-HFO achieves the lowest LCOHT on the Singapore route at 0.502 ¢/ton·km and 0.392 ¢/ton·km for 40 K and 80 K ships, respectively, while the SOFC system exhibits the highest LCOHT on the South Korea route at 1.189 ¢/ton·km and 0.852 ¢/ton·km for 40 K and 80 K ships. ICE-HFO emits the highest CO₂ emissions at 41,333 tons/year for the 80 K ship transporting to South Korea, whereas ICE LNG–SOFC and ICE HFO–SOFC hybrids reduce emissions by 62 % and 50 %, respectively, with LCOHT increases of 23 % and 22 %, demonstrating a trade-off between cost and environmental impact. Sensitivity analysis identifies ship speed as the dominant factor influencing LCOHT, with a 20 % speed reduction to 12 knots increasing LCOHT by 0.318–0.460 ¢/ton·km. NPV analysis indicates that the ICE-HFO system for the 80 K ship achieves the highest profitability, with PBPs as short as 2.76 years depending on time charter rates and hydrogen sale prices. In contrast, the SOFC system shows significantly longer PBPs, exceeding 10 years under typical market conditions. Transportation to Singapore is more profitable than to South Korea due to higher annual hydrogen delivery, and 80 K ships consistently outperform 40 K vessels in economic performance. These findings provide guidance for selecting optimal propulsion systems in future hydrogen transportation strategies.