Hydrogen Articles
Possible Hydrogen Storage Breakthrough. November 19, 2006
Hydrogen Working Group Formed. June 11, 2006
Hydrogen Refueling Demonstration. December 5, 2004
Hydrogen ICE Cars. September 26, 2004
Possible Hydrogen Storage Breakthrough.
The German Institute of Coastal Research (GKSS) recently announced a breakthrough in storing hydrogen on vehicles.
Hydrogen storage has been one of the leading problems in developing hydrogen powered cars.
Storing Hydrogen under high pressure in high-strength fiber-glass cylinders requires too much space and interferes with cost-effective design. Storing Hydrogen as a liquid, cryogenically, also takes up too much space and is more difficult to handle in an everyday fueling station.
Until now, hydrogen storage in metal hydrides has required too large or heavy a storage container or required several hours for refueling.
The breakthrough was accomplished by using light metal hydrides as nanocrystalline materials, prepared using high energy milling.
The nanocrystalline material allows complete refilling of the storage tank in minutes rather than hours as was previously the case. In addition new catalysts developed at GKSS enable absorption at room temperature and desorption at 200°C.
Hydrides store about 60% more hydrogen by volume as compared to liquid storage and hydride tanks are flexible with respect to geometry making it easier to design cars. They are safer in the event of an accident where the tank might be ruptured.
GKSS believes it will now be possible to develop hydrogen powered automobiles using reversible, light weight metal hydrides.
Source: www.gkss.de/Themen/W/WTP/wasserstoff/index.html
November 19, 2006
Hydrogen Working Group Formed.
The American Nuclear Society formed the Nuclear Production Hydrogen Working Group at its annual meeting in Reno, June 4-8. “The Working Group is organized to advance the utilization of nuclear energy in the critical need to supplement and replace fossil fuels for the generation of electricity.”
The Group's initial areas of potential advancement are with respect to reduction in the cost of hydrogen production;
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Through co-production of electricity and hydrogen;
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By higher temperature electrolysis; and
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Development of hydrogen production through thermo-chemical processes in next generation high-temperature reactors
Several sessions at the ANS meeting focused on the need to increase nuclear generation of electricity so as to reduce the generation of green house gasses and to provide the electricity needed to achieve independence from foreign oil.
Establishment of the working group provides an official identity for the American Nuclear Society’s efforts with respect to hydrogen and a vehicle for official collaboration with other organizations such as the National Hydrogen Association.
June 11, 2006
Hydrogen Refueling Demonstration.
A visit to the Shell hydrogen refueling station to watch refueling of GM Fuel Cell cars showed the potential…and the problems… of hydrogen as a fuel to replace gasoline.
The fueling took place at a hydrogen pump that, from outward appearances, looked much like the several gasoline pumps at the Shell station on Benning Road. The fueling hose and nozzle were similar to the usual gasoline hoses except the nozzle had to be clamped on to the car’s fuel intake with a small lever mounted on the nozzle.
A second cable with a multiple pronged plug was attached to the car: this cable removed the static electricity from the car and also measured the pressure in the fuel tank so as to make fueling quicker and safer. (The second cable was the single feature most visibly different from the usual gasoline fuel pump.)
The hydrogen was pumped at 5,000 psi (350BAR) into the car’s fuel tank. The station could be modified to handle hydrogen at 10,000 psi (700BAR) with a different clamp on nozzle.
The Hydrogen was delivered to the Shell station in liquid form by cryogenic trucks from Air Products Corporation. The liquid hydrogen is stored underground in a 1400 gallon steel tank, essentially a large thermos bottle, with some of the hydrogen boiling off as a gas at the top of the tank. As needed, the extremely cold hydrogen gas is fed through a series of evaporator coils exposed to the outside air to raise the temperature of the gas to near ambient temperature. The gas is then compressed and stored in a series of high pressure containers before it is piped to the fueling station when fueling begins. The multiple high pressure tanks ensure a steady stream of hydrogen gas if fueling requires more hydrogen than is stored in a single high pressure container.
All the piping at the station is rated 30,000 psi and is ASME certified.
The storage for the underground tank, evaporators, compressor and high pressure containers covers an area of approximately 2500 square feet which is enclosed with an eight foot high steel fence, with spikes for security.
When queried about using electrolysis for generating hydrogen locally at the station, the Air Products representative said that liquid hydrogen was the least costly approach even when it had to be transported several hundred miles by cryogenic truck; and even where electricity for electrolysis was very inexpensive.
(Liquefying hydrogen uses energy equivalent to roughly one third of the energy of hydrogen; this casts some doubt over whether liquid hydrogen will ultimately prove the least costly method for generating hydrogen for use at fueling stations.)
Since the primary purpose of the Shell station is to demonstrate hydrogen refueling and to refuel the fleet of fuel cell vehicles in the Washington D.C. area, safety was given inordinate attention…So much so, that the casual observer would have been scared by the process, something that could detract from securing acceptance by the public of hydrogen as a fuel.
Observers were asked to stand ten feet away from the car and the attendant fueling the car was required to wear a flame resistant smock. Also, considerable emphasis was made about preventing a spark from static electricity.
Other safety features were to be expected: a breakaway connection in case the hose is ripped from the pump with a solenoid shutoff valve to prevent the flow of hydrogen to the atmosphere; a similar solenoid shutoff in the event the entire pump is ripped from its foundation; and other shut off valves back at the high pressure containers in the storage area. Hydrogen detectors were installed to alert the attendant should hydrogen escape to the air.
Overall, the refueling of the GM fuel cell vehicle went smoothly and demonstrated the ease of refueling with hydrogen.
The station will also be able to dispense liquid hydrogen to cars that are outfitted with cryogenic tanks rather than tanks holding hydrogen in gaseous state at 5 or 10 thousand psi.
This
repot summarizes a demonstration by Shell, GM and Air Products to
representatives of the Department of Energy (DOE) on
December 5, 2004
Hydrogen ICE Cars.
Recent activity to develop Internal Combustion Engines (ICE) to run on hydrogen (H2) is making headlines.
Ford and Mazda have both announced experimental cars that use hydrogen.
BMW
unveiled its H2 ICE car in
BMW’s management board member Burkhard Goeschel said "Our drive toward the future is called hydrogen."
Ford said they view the H2 ICE car as an important step towards a hydrogen fueled future, with fuel cells the ultimate objective.
Ford
also indicated that the H2 ICE car would provide the market demand for
construction of the necessary fueling station infrastructure.
The
Argonne National Laboratory’s Center for Transportation Research (CTR)
is conducting research to support the “FreedomCAR goal, adopted by the
U.S. Department of Energy (DOE) and industry, to develop internal
combustion engine (ICE) powertrain systems operating on hydrogen with a
cost target of $45/kW by 2010 and $30/kW in 2015”,
The
Ford C-MAX H2 ICE uses a supercharger to enable the Ford Focus to have
performance similar to the corresponding car using a gasoline
engine.
The
hydrogen/air-ratio of an H2 ICE can be adjusted over a wide range because
of the combustibility characteristics of hydrogen. This means that both
very lean and very rich hydrogen/air mixtures are possible, enabling
optimal control of fuel consumption and NOx emissions.
The
major problem with using hydrogen is caused by its wide range of
combustibility: hot spots in the cylinder can cause pre-ignition. This is
one reason why Diesel’s will have greater difficulty using hydrogen than
gasoline engines.
Getting
the fuel air mixture right, which is aided by the supercharger, and
cooling the fuel mixture properly are keys to getting the H2 ICE to
operate efficiently with low emissions. Adding safety features to the
engine, such as to prevent crankcase build up of hydrogen, are also
essential. As a result, it is unlikely that existing IC engines can be
easily modified in the field to use hydrogen. The H2 IC engine will need
to be factory built and installed in a car that is designed to house the
hydrogen fuel tank.
For
reports on the status of hydrogen and on the challenges of a hydrogen
economy, click on the H2 symbol on the home page.
H2: Sooner rather than Later?
There are only two known technologies that have the potential to eliminate America’s dependence on foreign oil: They are hydrogen powered vehicles and electric powered vehicles.
While fuel cells are the ultimate technology for using hydrogen, internal combustion engines (ICE) can be
modified
to burn hydrogen—now. Also
many believe that introducing ICE vehicles using hydrogen, sooner
rather than later, will stimulate the development of the hydrogen (H2)
distribution infrastructure needed to support fuel cell cars.
Countering
this view a study sponsored by GM and some Oil companies will apparently
say that burning hydrogen in modified internal combustion engines will
produce as many pollutants as burning gasoline, thus making the H2 ICE
vehicle an unattractive alternative.
Other car manufacturers, such as BMW and Ford, say that the study is too negative and that H2 burning ICE vehicles can be developed to meet stringent California emission standards.
The
only other technology that can eliminate dependence on oil is the electric
powered vehicle (ev), but it is stymied by battery technology. To date, no
battery powered car has been developed that has the necessary range,
acceleration and speed to meet the needs of the average driver. Costs and
recharging times have also proven to be negative factors…And disposal of
batteries has created environmental issues.
The hydrogen powered car using fuel cells is seen as the most likely alternative for eventually replacing oil in the transportation sector. Fuel cells are currently much too expensive to be commercially viable, though research has the potential to lower their costs substantially.
The lack of a distribution system for hydrogen creates a chicken and egg situation: Why develop fuel cell cars when there is no distribution system? Or why develop a distribution system when there are no cars for it to serve?
The
H2 IC engine is seen as a way to stimulate the development of a hydrogen
distribution system. Meanwhile, the infrastructure to manufacture and
service IC engines is already in place, permitting a smooth transition to
the H2 economy.
The
recent National Academy of Sciences report calling the Bush
administration's $1.7 billion hydrogen program too expensive, misses the
mark.
Recognizing
that the H2 car is one of only two known technologies capable of weaning
America from its dependence on foreign oil would seem to support the need
for more research, not less. It would also seem to increase the
desirability of accelerating the introduction and mass production of the
H2 ICE car.
Producing and distributing hydrogen requires the resolution of many technical issues. These issues are described in the TSAugust reports Hydrogen Today and Hydrogen: Reality and Policy--Challenges and Alternatives.
None
of the issues appear insurmountable though there are basic trade offs
between using natural gas, coal or water to produce hydrogen. The
production of hydrogen will, under some alternatives, require large
amounts of electricity that can only be supplied using fossil or nuclear
fuels: Renewable energy alternatives, such as wind, are not capable of
generating enough power to produce sufficient hydrogen to meet the needs
of a hydrogen economy. All of these issues are summarized in the two
TSAugust reports on hydrogen.
ICE May Be Bridge to H2
The
internal combustion engine could be the bridge to the hydrogen future.
Automobile companies have built H2 cars with internal combustion engines,
at least one with superchargers to increase efficiency: This
manufacturer claims that its hydrogen powered ICE is 25% more fuel
efficient than a comparable gasoline engine. By one estimate an ICE
suitable for the use of hydrogen will only cost $1,000 more than the
standard ICE.
ICE’s
have the advantage of using existing manufacturing capabilities as well as
the service industry’s trained mechanics for servicing ICE’s.
Local
fueling stations will need to be put in place to supply hydrogen to these
cars but, as described in Hydrogen
Today, such systems are available.
For
a complete analysis of hydrogen see Hydrogen
Today and our subsequent report Hydrogen:
Reality and Policy—Challenges and Alternatives.
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