NHA NEWS

Highlights from HYPOTHESIS II


by Paul Scott, Touchstone Technology

The NHA meeting in Texas? Not quite, but Norway, the second largest oil-exporting nation in the world, was the site of the second biannual meeting of HYPOTHESIS (HYdrogen POwer THeoretical and Engineering Solutions) during the week of 18-22 August 1997.

Hydrogen production, safety, systems, transportation, liquid hydrogen, and hydrides were the key topical headings of the sessions. Fuel cell technology was highlighted on the final day. The 177 attendees represented 29 countries, with particularly good representation from Japan, Russia, India, and the Ukraine. The eight attendees from the U.S. repeatedly found discussions rarely held in the states, such as detailed plans for reducing CO2 emissions and the effects of climate change. Climate change as a present reality was suggested by the exceptional Scandinavian summer, with cited record water temperatures of 25°C in both the Baltic and North Seas, rainless months of the warmest Norwegian weather since 1921, and the disastrous rains and floods in Poland and Germany.

Representatives from 50 firms in 11 countries were welcomed by the attendees, and discussions of product characteristics were quite as common as academic topics. The worldwide hydrogen equipment market was prominent.

Renault/Volvo Fuel Cell Car

Renault, Volvo, Air Liquide, Ansaldo, and De Nora chose this meeting to describe their FEVER fuel cell-powered automobile design. Jean-Claude Griesemann, Director of Research for Renault, detailed the subsystems of the PEM fuel cell-powered car being tested now, which is expected to achieve a 500-km range using 8 kg of liquid hydrogen fuel. Griesemann addressed concerns about LH2 boil off, citing 12 days storage at which point a controlled release through a catalytic burner (developed by the Technical Institute of Stockholm, Sweden), converting the hydrogen to water, would begin.

The drive train is a series of hybrid configurations, with 3.2-kWh nickel metal hydride battery storage to provide up to 45-kW in peak power for acceleration and to absorb braking energy. The fuel cell is sized for 30 kW, with three stacks of 45 cells each operating with 2.5 atm hydrogen and 3 atm of pressurized air. Fuel cell stack efficiency is cited at 56% at a nominal 0.7 volts per cell, with an overall efficiency of 38%. The electric drive is claimed 92% efficient. A DC-DC converter is used to provide 12 and 24 volt auxiliary power. Ballard was acknowledged to have the lead in power density, but a viewgraph detailed how the Italian group (Ansaldo/De Nora) was gaining. Fuel cell costs were briefly described, with present membrane cost of US$270/kW and an objective of $30-$50/kW.

Griesemann noted that, before the introduction of automotive catalytic convertors in 1993 in France, cars contributed 60% of CO, 45% of NOx, and 30% of HC emissions. This technology could be economically mature between 2005 and 2010.

Fossil Fuel Sources–CO2 Sequestration at Wellhead

The three million barrels a day oil production of Norway is barely exceeded by the four million population. The conference was organized so as to allow leaders of the local energy industry to give some of the key HYPOTHESIS addresses.

A dynamic model of reformer operation was given by Prof. John Amphlett of the Royal Military College of Canada. He uses a finite difference analysis to investigate the time response of a small reformer.

Cryoplane Progress

Dr. Heinz Klug, of Daimler-Benz Aerospace, summarized the German-Russian cryoplane joint venture, noting that a budget of 62 million DM (15 million of which is Russian) is being directed towards a Dornier DO328 conversion using a modified PW306B engine. Demonstration flights in year 2002 are planned. The goal of this program is to prove safe, reliable, and economically compatible operation.

Klug noted that the growth rate of the aviation industry, at 6% per year, less an average 2%/yr efficiency increase, results in A/C CO2 emissions increasing at 4% per year. He detailed the difficulty of offsetting this increase, even by the most aggressive scenario of introducing hydrogen-powered aircraft.

Klug also discussed the lack of knowledge of the environmental effect of water contrails, noting that, at above 12 km altitude, emission lifetimes could exceed 100 years, but that the concern would not be with water vapor but with ice crystals. Carbon and sulphur nuclei, present in the exhaust of conventional jets, are generally thought necessary as nucleation sites for ice crystals. One concludes that high-altitude flights of a hydrogen-fueled vehicle are required as an experiment in pure water contrails.

NOx emissions remain as an environmental concern, and micromix combustor nozzle designs were described as a means of reducing the NOx in the exhaust below 30 ppm.

Hydrogen Safety

Dr. Fredrick Edescuty presented the keynote on safety, discussing several “case-study” examples of accidents in way of illuminating his four conditions for safe use of a combustible gas:

He also noted that, “Anyone who thinks they can build a foolproof system has overlooked the ingenuity of fools.”

Catherine Gregoire-Padro (U.S. Department of Energy Hydrogen Program Manager) presented the recent improvements in the [U.S.] National Renewable Energy Laboratory-developed fiber-optic hydrogen sensor, including a two-wavelength system that includes a reference beam in addition to the one which is used to sense the presence of hydrogen. She emphasized the advantages of having no electrical wires in the hydrogen environment.

After briefly describing the Palm Desert and X-33 programs, Dave Haberman (DCH Technology) listed the challenges which must be overcome to do such projects:

The National Hydrogen Association safety-related activities on an international scale were presented by Karen Miller as a part of her presentation on the “Role of the NHA in Strategic Planning for the Hydrogen Economy: An International Initiative.” The NHA has served to relate the interests of hydrogen industry to the initiatives of the International Energy Association (IEA), including the essential step of formulation of standards which promote our commercial interests.

Hydrogen Storage

Liquid hydrogen storage was reviewed by Dr. W. Peshka of the German Aerospace Establishment (DLR), including descriptions of cryo-refrigerators and engine fuel injectors. He also discussed the advantages of hydrogen-fueled engines, noting that the BMW hydrogen engines have 1/10 the emissions of their gasoline-powered equivalents.

Other papers discussed large-scale liquid hydrogen transport by air and by sea, and the pumping and cooling of liquid hydrogen.

Hydride papers concentrated on the characteristics of different alloys, and several papers examined the mechanisms of metal hydride batteries.

Fuel Cell Studies

The question of whether hydrogen fuel can be fed in “dead-end mode” to a PEM fuel cell, or whether recirculation was necessary, was treated by Rudolf Metkemeyer, of Centre d’Energetique, École des Mines des Paris. He observed air passing through the membrane accumulated on the hydrogen side with a time constant slightly in excess of one hour, which made recirculation and some purge necessary.

The use of small fuel cells for household and business cogeneration was analyzed by Jurgen Garche of the German Center for Solar Energy and Hydrogen Research, who found that a comparatively large portion of the energy requirement was for thermal energy and, hence, that perhaps fuel cells were too efficient for this application.

Further presentations included one on CO tolerance of PEM fuel cells by Gaetano Squadrito, of Instituto CNR-TAE (Italy). He presented the experimental results of a study on CO-tolerant anodes for PEFC.

Unique Hydrogen Applications

The use of hydrogen energy in tourism development was explored by Zeljko Josipovic, who described the 641 Croatian Isles (located off the Adriatic coast and within 200 miles of Italy) as a proposed site for ecotourism. Use of adequate wind and sun resources would be used to avoid damaging the sensitive ecology by oil use.

The economics of introduction of hydrogen to city centers were discussed by David Hart who, as a first example, has studied London. He introduced “externality costing,” which expresses the monetary value of environmental and health damage, which is factored back to the cost of the polluting emissions. He finds the value of targeted hythane for motive power to be as high as US$200/GJ, in excess of US$5/100 SCF hydrogen! He suggests fuel replacement in gas turbines in city centers would be one of the best uses of hydrogen.

©1997. All Rights Reserved. A Publication of the National Hydrogen Association.
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