Generation, of the energy carrier HYDROGEN In context ... - needs

NyOrka Page 13 12/18/2008Table 3 Description of LCA phasesLCA phase DescriptionFuel supply The station uses grid electricity and tap water to produce compressedgaseous hydrogen ready for use in fuel cells or internal combustion engines.ProductionOperationDisposalManufacturing of electrolyzer, compressor and storage modules, dispenser,buffer tank, nitrogen bottles and walls and foundations. On-site assembly.Replacement of electrolyzer cell package, diaphragms and hydraulic oil forthe compressor. Maintenance and overhaul materials for e.g. pipes andfittings, the nitrogen bottles are neglected as supplies due to low dataavailability. Lye (KOH) to facilitate the splitting of H 2 O, Nitrogen to flushthe cell stack when the process is stopped or in time for maintenance orreparation, this function becomes less needed if the whole module is keptunder pressure during iAll metals are recycled and are not included as the cut-off approach is used.It is assumed that all other materials are transported to landfill or recyclingplant.The hydrogen production facility is made from several modules which are manufacturedseparately and then assembled on-site. The most important of those can be seen in Figure 5which shows the main division of the station into its main components.Figure 5 Main components of an electrolytic hydrogen filling station.The most important figures and statistics related to the hydrogen station modelled can beseen in Table 4.Table 4 Parameters for the studied hydrogen production facilities in current situation.Parameter Unit Current(as of 2003)ElectrolysisElectricity required kWh / kg GH 2 62- for electrolyser kWh / kg GH 2 53- for compressor kWh / kg GH 2 8Water required litres / kg GH 2 10