Comparative life cycle assessment of offshore hydrogen pathways from Black Sea H2S: pipeline integration, sulphur recovery, and ammonia conversion

Official URL: https://dx.doi.org/10.1016/j.seta.2026.105309

This study presents a climate-integrated Life Cycle Assessment of offshore hydrogen production from hydrogen sulphide (H2S) in the Black Sea, powered by offshore wind energy. Three system configurations are evaluated: (i) direct hydrogen integration via pipeline injection, (ii) environmentally controlled production with sulphur recovery, and (iii) hydrogen conversion to ammonia for transport and storage. A key methodological contribution is the use of daily wind power generation derived from location-specific climate projections, enabling dynamic estimation of electrolyser output instead of static capacity factors. The proposed framework estimates a lifetime hydrogen production of approximately 11,667 t H2 over a 30-year assessment period, representing a 6.6% increase compared with a conventional constant-capacity-factor approach. Environmental impacts are quantified using ReCiPe 2016 midpoint indicators, focusing on Global Warming Potential (GWP) and Fine Particulate Matter Formation (FPMF). Hydrogen-based scenarios exhibit nearly identical climate performance, with GWP-100 values of 0.693 and 0.694 kgCO2-eq./kgH2-eq. for the baseline and sulphur recovery scenarios, respectively. In contrast, uncontrolled sulphur release increases the FPMF-100 indicator from 0.553 to 9,280.6 gPM2.5-eq./kgH2-eq., highlighting the critical importance of sulphur management. These findings demonstrate that infrastructure design, sulphur management, and energy carrier selection are the primary determinants of the environmental performance of offshore H2S-based hydrogen systems.