PRESENT STATUS OF ADVANCED WATER ELECTROLYSIS

ABSTRACT In present commercial electrolyser technolgy, the advantages of electrolysis, i.e. simplicity, reliability and high product purity, are fully realized. A hydrogen market share of about 1 % reflects the fact that the special advantages of electrolytic hydrogen production are not saleable on the rather large scale represented by the major current uses of hydrogen. Although the cost of making hydrogen today is lowest for the reforming process based on natural gas or naphta, this does not mean that sequence of economic priorities will never change, e.g. Canada, Federal Republic of Germany, France and likely Belgium, will turn over in the near future to the use of non-fossil-derived hydrogen, not only as a chemical feedstock but also as an attractive fuel because of its highest energy density per unit weight of any chemical fuel. Over the past 5 to 10 years, several advanced electrolysis concepts and technologies have emerged, which appear to offer prospects for substantially increasing electrolyser efficiency and at the same time reducing capital costs. Looking to the achievements it appears therefore reasonable to expect that these appropriately directed research and development efforts will result in commercial advanced electrolysers that can achieve 90 to 95 % efficiency at capital costs of $ 140 to $ 180 per kilowatt.