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Topic: Liquid hydrogen

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In the News (Wed 24 Apr 19)

  Universal Industrial Gases, Inc...Hydrogen H2 Properties, Uses, Applications
Hydrogen is mixed with inert gases to obtain a reducing atmosphere, which is required for many applications in the metallurgical industry, such as heat treating steel and welding.
Hydrogen is used in large quantities as a raw material in the chemical synthesis of ammonia, methanol, hydrogen peroxide, polymers, and solvents.
Hydrogen is used as a carrier gas for such active trace elements as arsine and phospine, in the manufacture of semi-conducting layers in integrated circuits.
www.uigi.com /hydrogen.html   (1117 words)

 Liquid Hydrogen
Stable hydrogen is in the form of a diatomic molecule.
Liquid hydrogen is used extensively as a fuel in rocketry and more recently in commercial transportation.
Hydrogen is extremely flammable as with a small ignition energy it will combine with the oxygen is air with a strong exothermic reaction.
www.eng.fsu.edu /cryolab/liquidhydrogen.htm   (248 words)

 Liquid hydrogen - Wikipedia, the free encyclopedia
Liquid hydrogen is the element hydrogen in the liquid state.
It is a common liquid rocket fuel for rocket applications.
Liquid hydrogen is typically used as a practical form of storing hydrogen.
en.wikipedia.org /wiki/Liquid_hydrogen   (375 words)

 Hydrogen As an Alternative Fuel
Liquid hydrogen is the best alternative fuel for AAN platforms; however, further research is needed to move the hydrogen fuel technologies from prototypes to usable military hardware and to optimize power outputs from internal combustion engines (ICE's), gas turbine engines, and fuel cells.
Hydrogen burns in air at concentrations in the range of 4 to 75 percent by volume (methane burns at 5.3 to 15 percent concentrations by volume).
Liquid hydrogen storage is preferred to compressed gas storage since more hydrogen can be stored in the liquid state than in the gaseous state.
www.almc.army.mil /alog/issues/MayJun00/MS492.htm   (2224 words)

 Liquid Hydrogen
Hydrogen is normally vaporized and used as a gas.
Withdrawal of liquid from a tanker, tank, or liquid cylinder requires the use of a closed system, with proper safety relief devices, which can be evacuated and/or purged to eliminate the possibility of creating a flammable atmosphere or explosive mixture of liquid air and liquid hydrogen.
Gaseous and liquid hydrogen systems must be purged of air, oxygen, or other oxidizers prior to admitting hydrogen to the systems, and purged of hydrogen before opening the system to the atmosphere.
www-safety.deas.harvard.edu /services/hydrogen.html   (1236 words)

 Hydrogen Economy
Hydrogen does not occur in the free state in nature, therefore, it must be extracted from other chemical compounds.
Hydrogen is a product from reactions between the active metals of groups I and II and water.
The use of hydrogen as an industrial fuel such as in generating electricity is also a viable option for use of hydrogen fuel.
members.tripod.com /lyng/hydrogen.htm   (1149 words)

 Hydrogen (29-Oct-2006)   (Site not responding. Last check: 2007-10-12)
Liquid hydrogen has a density of 0.07 grams per cubic centimeter, whereas water has a density of 1.0 g/cc and gasoline about 0.75 g/cc.
Since hydrogen is not available in significant quantities in nature in pure form, the main present way of getting hydrogen is steam methane reforming, and this will probably remain the most economical way as long as methane (natural gas) is available cheaply and in large quantities, and hydrogen is required only in small quantities.
The problem is that while hydrogen supplies three times the energy per pound of gasoline it has only one tenth the density when the hydrogen is in a liquid form and very much less when it is stored as a compressed gas.
www-formal.stanford.edu /jmc/progress/hydrogen.html   (3415 words)

 Hydrogen.com   (Site not responding. Last check: 2007-10-12)
The potential contribution of a particular property of hydrogen to a particular hazard depends strongly on the specific conditions under which hydrogen is released and/or confined.
The hydrogen extracted from a gallon of water using a hydrogen generator could drive a hydrogen fuel cell vehicle as far as gasoline vehicles travel today on a gallon of gasoline.
Hydrogen may be stored in four main ways, including as a gas, as a liquid, as slush and as metal hydrides.
www.hydrogen.com /faq.asp   (2218 words)

 Hydrogen: What Form Fits?
Cooling the hydrogen increases its density, but a tremendous amount of energy is required both to keep the tanks cold and, when needed, to turn the liquid back into a gas that can be delivered to an engine or fuel cell.
Hydrogen gas is catalyzed by the metal to stick in the nanotubes' honeycomb structures.
Some of the hydrogen is absorbed by the metals to form metal hydrides, but most of it leaks onto the surface of the nanotubes and sticks in the nanotubes' honeycomb structures.
www.rps.psu.edu /hydrogen/form.html   (1448 words)

 FuelCellStore.com's Hydrogen Storage Page-cryogenic hydrogen storage, compressed hydrogen, carbon nanotubes
The result is the hydrogen released from the tank is extremely pure, but the tank's lifetime and ability to store hydrogen is reduced as the impurities are left behind and fill the spaces in the metal that the hydrogen once occupied.
Hydrogen can be compressed into high-pressure tanks where each additional cubic foot compressed into the same space requires another atmosphere of pressure of 14.7 psi.
The margin of safety concerning liquid hydrogen storage is a function of maintaining tank integrity and preserving the Kelvin temperatures that liquid hydrogen requires.
www.fuelcellstore.com /information/hydrogen_storage.html   (963 words)

 BMW's Hydrogen Power for Cars
Although liquid hydrogen is clean burning, it is not the easiest fuel to handle.
In order to remain in a liquid state, hydrogen must be kept at -423 degrees F. Essentially, a stationary vehicle, merely sitting in the sun, could burn fuel and even exposure during the fueling process causes the gas to evaporate.
Severe crashes were done where the hydrogen tank was severely damaged or punctured, results showed that the liquid hydrogen simply dissipated in the air.
www.theautochannel.com /news/date/19990317/news020599.html   (1570 words)

 Praxair, a supplier of hydrogen, liquid or gas.
Hydrogen is a component of water, minerals and acids, as well as an essential part of all hydrocarbons and essentially all other organic substances.
Colorless, odorless, tasteless and nontoxic, hydrogen exists as a gas at atmospheric temperatures and pressures.
Hydrogen is flammable and burns in air with a pale blue, almost invisible flame.
www.praxair.com /hydrogen   (206 words)

 Safe Hydrogen LLC -- About Us
Efficient and safe storage and delivery of hydrogen is the major technical challenge of utilizing hydrogen as an alternative energy carrier.
Liquid hydrogen is a proven method of storing hydrogen, but it takes substantial energy to liquefy the hydrogen and there is continual "boil off" of hydrogen during storage.
Because hydrogen is also contributed by the water in the reaction, the Safe Hydrogen fuel carries an impressive hydrogen generation potential.
www.safehydrogen.com /technology.html   (777 words)

 Aluminum battery Data Hydrogen Data Hydrogen Facts Data Hydrogen Data Hydrogen Facts Data Hydrogen Data   (Site not responding. Last check: 2007-10-12)
Hydrogen is a colorless, odorless, tasteless, flammable and nontoxic gas at atmospheric temperatures and pressures.
Liquid hydrogen has a relatively high thermal coefficient of expansion compared with other cryogenic liquids.The hydrogen molecule exists in two forms: ortho and para, named according to their types of nuclear spin.
Hydrogen, though, is an exception, becoming heated to a slight extent under these conditions (increasing about 10 F in temperature, for example, when throttled from 2000 psig to atmospheric pressure).
www.hydrogenappliances.com /Hydrogendata.html   (2317 words)

 Metallic Hydrogen Fact Sheet   (Site not responding. Last check: 2007-10-12)
Additionally, solid metallic hydrogen is predicted to contain a large amount of energy that might be released quickly as an explosive or relatively slowly as a lightweight rocket fuel.
Because hydrogen is the lightest and simplest off all elements and composes about 90% of the atoms in the visible universe, scientists have a broad spectrum of interest in its properties and phases.
Entering the liquid hydrogen, the shock pressure first drops, then reverberates many times between parallel sapphire anvils until the final pressure, density and temperature are reached.
www-phys.llnl.gov /H_Div/GG/metalhydrofact.html   (1001 words)

The Space Shuttle uses hydrogen as a fuel, because its mass is low, and the fuel is carried in an external fuel tank that is jettisoned during lift-off.
Hydrogen can also be burned directly in engines much like those that run on gasoline, but the US Energy Department's goal is fuel cells because they get twice as much work out of a pound of hydrogen.
The difference is that a fuel cell combines oxygen from the air with hydrogen to produce an electric current, and water as a byproduct; an electrolyzer runs an electric current through water, to split the water molecule into its constituent hydrogen and oxygen atoms.
www.dalefield.com /earth/hydrogen.html   (1429 words)

 United Nuclear - Hydrogen Fuel Systems
Powering a vehicle by Hydrogen is by no means a new idea, and in fact, almost all automobile manufacturers are currently developing a new generation of vehicles that run on Hydrogen as opposed to Gasoline.
The Hydrogen generator is either powered by Solar electric panels or a wind turbine set-up, either of which makes Hydrogen fuel at virtually no cost.
Choosing liquid does solve the density problem since liquids are far more dense than gasses, so you can reduce the amount of tanks and their sizes required to power the car.
www.switch2hydrogen.com /h2.htm   (1462 words)

Hydrogen derived from large-scale reformers can also be “injected” into solid hydrogen storage containers such as metal hydrides and nanotubes.
Hydrogen production processes are most commonly used for industrial applications (primarily as a chemical for petrochemical, electronics, and food industries).
Some estimates place the necessary target for economic on-board hydrogen storage for vehicles at five percent by weight with reversible hydrogen storage at 120°C. In addition to hydrides and nanotubes, other chemical means for storing hydrogen are being explored, such as immersing the hydrogen in a solution of sodium borohydride or sodium tetrahydridoborate.
www.crest.org /hydrogen/hydrogen_fuelcell_reformstorage.html   (1353 words)

 DOE Hydrogen Program: DOE H2A Delivery Analysis
Hydrogen must be transported from the point of production to the point of use, and handled within refueling stations or stationary power facilities.
The pipeline transports the hydrogen to a compressed gas terminal where the hydrogen is loaded into compressed gas tube trailers.
For example, if the user selects liquid hydrogen truck delivery for a given market and penetration rate, the model calculates not only the number and cost of the trucks required to deliver the fuel to refueling stations (or forecourts), but also the cost of appropriately-sized liquefiers, terminal storage, truck loading facilities, and forecourts.
www.hydrogen.energy.gov /h2a_delivery.html   (1255 words)

 Liquid Hydrogen Study Group   (Site not responding. Last check: 2007-10-12)
If the economics are competitive with other storage systems then the hydrogen could be in liquid form and so create a large new market for cryogenic hydrogen and all the associated cryogenic technology for storage and handling.
In due course there could be 1,000s of hydrogen buses operating in all our cities and so the demand for liquid hydrogen becomes tens of thousands of tons (100s of millions of litres).
More detailed information about hydrogen as a fuel for buses and cars can be found in the hydrogen section of the site.
www.hydrogen.co.uk /what's_new/liquidh2_studygroup.htm   (422 words)

 USATODAY.com - GM, BMW to develop liquid hydrogen refueling technology   (Site not responding. Last check: 2007-10-12)
Liquid hydrogen is extremely cold, so the equipment must be able to adequately protect people involved in the refueling and the vehicles.
In March, GM and Shell Hydrogen said they were bringing a fleet of fuel-cell minivans to Washington for lawmakers and policymakers to use — also touted by the companies as a partnership to speed the development of hydrogen technology.
Right now, hydrogen vehicles aren't viable because of their cost and the lack of means to refuel and maintain them.
www.usatoday.com /tech/news/techinnovations/2003-04-09-gm-bmw_x.htm   (447 words)

 Jumpin' Jupiter!
It was unexpected for several reasons: (1) we used liquid hydrogen, rather than solid hydrogen that conventional wisdom indicated was required; (2) we applied a methodology--shock compression--that had never before been tried in order to metallize hydrogen; and (3) we were working at higher temperatures (3,000 K) than metallization theory specified.
The liquid hydrogen (or deuterium) was a half millimeter thick, and the target was cryogenically cooled.
Our conductivity data for hydrogen are essentially the same as those for the liquid metals cesium and rubidium at 2,000 K undergoing the same transition from a semiconducting to metallic fluid.
www.llnl.gov /str/Nellis.html   (2729 words)

 Liquid hydrogen turns superfluid (November 2000) - Physics World - PhysicsWeb
Hydrogen is therefore already a solid at the temperature at which Bose condensation is expected to take place.
In the stable state, the OCS molecule is at the centre of the droplet and is surrounded by a thin layer of hydrogen, which is itself surrounded by a relatively thick shell of liquid helium-4.
When the experiment was repeated with deuterium in place of the hydrogen, the sharp peaks still persisted at 0.15 K, indicating an absence of superfluidity in deuterium at this temperature.
physicsweb.org /articles/world/13/11/3   (1141 words)

 Safe Hydrogen LLC -- About Us
Safe Hydrogen LLC is developing a new, patent-pending hydrogen storage and generation technology utilizing magnesium hydride slurry as a pumpable hydrogen fuel.
The hydrogen density of the slurry is twice that of liquid hydrogen, very safe to transport and stores at normal temperature and pressure.
Safe Hydrogen is currently operating under a grant from the US Department of Energy to demonstrate the technology against the requirements of the Automobile industry for on-board hydrogen storage that meets cost and safety targets as well as driving ranges for hydrogen powered automobiles equivalent to current gasoline powered cars.
www.safehydrogen.com /about.html   (758 words)

 Liquid helium, superfluidity
Using liquid air to produce liquid hydrogen and then the hydrogen to jacket the liquification apparatus, he produced about 60 cubic centimeters of liquid helium on July 10, 1908.
When helium is cooled to a critical temperature of 2.17 K (called its lambda point), a remarkable discontinuity in heat capacity occurs, the liquid density drops, and a fraction of the liquid becomes a zero viscosity "superfluid".
When helium is cooled to a critical temperature of 2.17 K, a remarkable discontinuity in heat capacity occurs, the liquid density drops, and a fraction of the liquid becomes a zero viscosity "superfluid".
hyperphysics.phy-astr.gsu.edu /hbase/lhel.html   (386 words)

 Fuel Cells 2000 : Hydrogen : Basics
Hydrogen is the lightest element, with a density of 0.08988 grams per liter at standard pressure, yet it has the highest energy content per unit weight of all the fuels — 52,000 Btu/lb, or three times the energy of a pound of gasoline.
Hydrogen is never found alone on earth — it is always combined with other elements such as oxygen and carbon.
Liquid hydrogen trucks have carried on the nation's roadways an average 70 million gallons of liquid hydrogen per year without major incident.
www.fuelcells.org /hydrogen/basics.html   (861 words)

 NASA - Liquid Oxygen and Liquid Hydrogen Storage
Overview: Liquid oxygen used as an oxidizer by the orbiter main engines is stored in a 900,000-gallon tank on the pad's northwest corner, while the liquid hydrogen used as a fuel is kept in an 850,000-gallon tank on the northeast corner.
The lighter liquid hydrogen is stored in a vacuum bottle located in the northeast corner of each pad.
It must be kept at an even lower temperature than the liquid oxygen: minus 423 degrees F. To move the liquid hydrogen to the pad, a small amount is allowed to vaporize, and the gas pressure exerted from the top of the tank pushes the fuel into the transfer lines.
www.nasa.gov /mission_pages/shuttle/launch/LOX-LH2-storage.html   (265 words)

 Hydrogen storage - Wikipedia, the free encyclopedia
Hydrogen storage is the main technological problem of a viable hydrogen economy.
However liquid hydrogen is cryogenic and boils around 20.268 K (–252.882 °C or -423.188 °F).
Even liquid hydrogen has worse energy density per volume than hydrocarbon fuels such as gasoline by approximately a factor of four.
en.wikipedia.org /wiki/Hydrogen_storage   (1288 words)

 Green Car Congress: BMW to Display Liquid Hydrogen Storage System and Bi-fuel Engine at NHA 2006   (Site not responding. Last check: 2007-10-12)
Of the major automakers working with hydrogen as a fuel, BMW holds a unique position—not only has it settled on hydrogen-fueled combustion engines as the interim step to a longer-term fuel-cell future (a stance Ford also takes), the German automaker focuses on liquid hydrogen fuel, rather than gaseous.
Liquid hydrogen offers a higher volumetric density (0.070 kg/liter) than gaseous (0.030 kg/liter @ 10,000 psi)—an important consideration when faced with a limited storage volume in a vehicle.
Liquid hydrogen requires 60% of its energy content to produce and liquefy it in the first place.
www.greencarcongress.com /2006/03/bmw_to_display_.html   (2152 words)

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