Development and assessment of an offshore-based integrated hydrogen production and liquefaction system

The conventional hydrogen production methods depending on fossil fuels raise sustainability concerns. Therefore, there is a crucial need to develop sustainable and energetically self-sufficient hydrogen production processes. In this paper, an integrated hydrogen production and liquefaction system is developed to meet the hydrogen energy needs of communities. For this purpose, the present integrated system is considered and applied to the Hornsea Wind Farm, being developed off the east coast of the East Coast in the North Sea. The system aims to produce gaseous hydrogen by an electrolyzer and liquefy it by utilizing the energy input coming from a wind farm. The thermodynamic analysis is performed for the overall system and its components using energy and exergy methods through balance equations. Furthermore, the parametric evaluations are implemented to investigate the effects of varying operational conditions and design parameters on some key energy and exergy performance indicators. Under the specified conditions, the current study obtains the following results: an overall energy efficiency of 70.45 %, an overall exergy efficiency of 57.32 %, and a specific energy consumption of liquefaction plant (SEC) of 62.24 kWh/kg-LH2. Moreover, the levelized cost of H2 for the plant is found to be $7.28/kg. This research also reveals the primary sources of exergy losses by providing valuable insights to enhance the system's exergetic performance with some potential optimization opportunities. Furthermore, this study is expected to help achieve a more sustainable and decarbonized energy future with green hydrogen production and liquefaction for use.