Abstract
Ammonia and hydrogen are increasingly considered promising low-carbon maritime fuels, yet their environmentalperformance within integrated offshore infrastructure remains insufficiently quantified. The novelty ofthis research lies in the subsystem-integrated life-cycle assessment of a renewable-powered Floating Storage andRegasification Unit (FSRU) that integrates offshore ammonia and hydrogen storage, regasification, onboardpower generation, seawater desalination, and hydrogen production within a unified framework. Unlike previousstudies that assess these subsystems separately, the present study evaluates their combined operation on a singleoffshore platform, capturing subsystem interactions and cross-system energy dependencies. An ISO-compliantcradle-to-gate life cycle assessment was conducted using the ReCiPe 2016 v1.1 Midpoint method to evaluateclimate change, freshwater consumption, marine ecotoxicity, marine eutrophication, and stratospheric ozonedepletion across three configurations, namely, conventional regasification, renewable-assisted power generation,and an integrated auxiliary subsystem. The results show that ammonia regasification is dominated by operationalenergy demand, with a climate change impact of 1.27 g CO_2-eq/kg NH3. In contrast, hydrogen regasification isdriven mainly by material production, with an impact of 5.68 g CO_2-eq/kg H2. For renewable power generation,high seawater pumping requirements increase the climate change impact to 101.9 g CO_2-eq/kWh for the oceanbasedsubsystem, while thermal energy storage contributes 16.6 g CO_2-eq/kWh in the solar-based subsystem.Hydrogen production via electrolysis remains highly electricity-intensive, resulting in climate change impacts of17.5–26.9 kg CO_2-eq/kg H_2 under grid-supported operation. Sensitivity analysis further indicates that onboardrenewable operation reduces climate change impacts by 20.7% for the solar-based subsystem and 76.3% for theocean-based subsystem. The main contribution of this work is the establishment of an integrated environmentalbenchmark for renewable-powered FSRUs, highlighting subsystem-level trade-offs and design pathways toreduce life-cycle impacts in offshore ammonia and hydrogen supply chains.
NETL
NSTL
Elsevier