Electrolysis technologies

Doenitz, W. et al., Recent advances in the development of high-temperature electrolysis technology in Germany, in Proc. 7th World Hydrogen Energy Conf., Moscow, 65,1988. 

In Europe, Spain is the third country - after Germany (18) and France (10) -as regards the number of chlor-alkali plants, with a total of nine. Nevertheless, Spain is ahead along with Germany, in respect to the number of plants (8) which are still using Hg-electrolysis technology. The membrane technology represents... 

The Hg-electrolysis technology is one of the major point sources of Hg contamination, and its impact on the environment has been studied worldwide [23-26]. Although mercury cell chlor-alkali industry is obsolete in most of the European Union countries [27], in Spain it will be allowed until the end of 2010. 

Minz, F.R. (1993) HCl-electrolysis - technology for recycling chlorine. Paper presented by Bayer AG at the Conference on Electrochemical Processing, Innovation Progress, Glasgow, UK. 

Krupp Uhde (1999) Brochure Alkaline Chloride Electrolysis Technology - Superior Krupp Uhde Membrane Process . 

The development of high current density electrolysis technology is a continuing effort. Asahi Chemical s focus is currently on the confirmation of stable long-term performance and reliability, in preparation for the supply of this process equipment and technology to chlor-alkali producers. 

Pressurised alkaline water electrolysis technology has been state-of-the-art for many years. The system efficiency of real electrolysers ranges from 62% to 70%, including all auxiliaries (AC/DC converter, pumps, blowers, controls, etc.) based on the lower heating value of hydrogen. 

As an example of a sectoral technology split, see the central electrolysis technology in Fig. 18.4. 

The second project area involves the optimization of water electrolysis technology. 

Han SD, Park KB, Rana R, Singh KC (2002) Developments of water electrolysis technology by solid polymer electrolyte. IndJChem 41 A 245-253... 

There are two well-established methods for electrolysing brine, the diaphragm cell and the mercury cell. However, recent developments in electrolysis technology, by chemical engineers, have produced the membrane cell (Figure 5.13). This method is now preferred to the other two because it produces a purer product, it causes less pollution and it is cheaper to run. 

Doenitz, W., et al. (1988), Recent Advances in the Development of High-temperature Electrolysis Technology in Germany , Proceedings of the 7th World Hydrogen Energy Conference, Moscow, pp. 65-73. 

Reducing the environmental impact of fossil fuel and synthetic fuel production requires a massive production of clean hydrogen which water electrolysis technology can offer in water electrolysis, electricity enables breaking water molecules into its elementary components hydrogen and oxygen. In the case where the electricity is produced free of C02 emissions hydrogen is also produced C02 free. 

As a result, the nuclear option can, in the short term, enable large C02 emission reductions based on available light water reactors and alkaline electrolysis technologies. The economic attractiveness of this solution depends on the electricity cost but also on the C02 and natural gas prices. 

Figure 5 Development roadmap of different electrolysis technologies...

In 2002 several manufacturers can provide advanced water electrolysis systems that are standardized, compact in size, need minimal operator intervention and require little maintenance. The basic electrolysis reaction has not changed. However new cell designs, materials of construction, standardized designs and manufacturing techniques have enabled manufacturers to decrease dramatically the fixed costs per unit of capacity for electrolysis technology. In addition, these new systems operate automatically and require very little maintenance, which reduces personnel costs48. 

Canada, a portion of the capacity installed at HydrogenATs merchant hydrogen plant in Quebec is based on electrolytic cells.40 Some of the companies that offer electrolysis technology are listed in Reference 40. 

FIGURE 5-5 Unit cost estimates for four current and four possible future electrolysis technologies for the generation of hydrogen. See Table 5-2 and discussion in text. NOTE O M = operation and maintenance. 

Finding 6-10. With the possible future technology advances, all but biomass and grid-electric or photovoltaic-based electrolysis technologies could be operated at costs less than those that Americans have been willing to pay in fuel costs for driving gasoline-fueled conventional vehicles. 

Current electrolysis technologies fall into two basic categories (1) solid polymer (which provides for a solid electrolyte) and (2) liquid electrolyte, most commonly potassium hydroxide (KOH). In both technologies, water is introduced into the reaction environment and subjected to an electrical current that causes dissociation the resulting hydrogen and oxygen atoms are then put through an ionic transfer mecha-... 

The total cost of a system at this scale would be about 2.5 million. It is anticipated that electrolysis technology scales with an 85 percent factor, so smaller-scale systems, with somewhat higher unit costs, are entirely feasible. For example, a facility with half the fueling capability (60 cars per day) would cost about 1.25 million, plus a 15 percent scaling factor. The scalability of electrolysis is one of the important factors relating to its likely use in early-stage fuel cell vehicle adoption. The electrochemical efficiency of electrolysis is essentially independent of scale. 

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