Liquefied hydrogen

Liquid hydrogen requires extreme precautions in handling because of the low temperature. Fueling is usually done mechanically with a robot arm. Even in large, centralized liquefaction units, the electric power requirement is high with 12 to 15 kilowatt-hours (kWh) needed per kilogram of hydrogen liquefied. 

Demirbas, A. 2002. Enel properties of hydrogen, liquefied petroleum gas (LPG), and compressed natural gas (CNG) for transportation. Energy Sources 24 601-610. 

Sulfur compounds/natural gas, hydrogen, liquefied petroleum gas (LPG) Zeolite... 

Compound Name Hydrogen, Liquefied Camphor Oil Nitrogen, Liquefied Nitrogen Tetroxide Oxygen, Liquefied Oil Mineral Carbolic Oil Litharge... 

HYDROGEN, LIQUEFIED Liquid Hydrogen, para Hydrogen Flammable Compressed Gas 0 4 0... 

Hydrogen, Liquefied — Fire Hazards Flash Point (deg. F) Not pertinent Flammable Limits in Air (%) 4.0 - 75.0 Fire Extinguishing Agents Let fire burn shut off gas supply Fire Extinguishing Agents Not To Be Used Carbon dioxide Special Hazards of Combustion Products Not pertinent Behavior in Fire Burns with an almost invisible flame Ignition Temperature (deg. F) 1,065 ... 

Butane can be used for the manufacture of maleic acid (thence to maleic anhydride), from which tetrahydrofuran is made by hydrogenation. Liquefied petroleum gas is also a feedstock for aromatics production (Fig. 1). 

A hydrogen liquefier consists of piston compressors that usually can operate at three pressure levels and a liquefier cold box. The cold box includes a... 

The facilities used to harvest the ocean thermal energy are called OTEC plants (Ocean Thermal Energy Conversion). To achieve their maximum potential they must be located in the open ocean near the equator, far from any market. Several schemes to transmit their output to the market have been examined. The most practical appears to be use the electric power to electrolyze water to produce hydrogen and oxygen. The oxygen can be vented and the hydrogen liquefied for shipment to market. This scheme allows the OTEC plant to produce a storable fuel that can be used for most energy needs. 

Jointly with Harteck we demonstrated the existence of the ortho-para modifications of deuterium using active charcoal as the catalyst at 20 K. Because of a breakdown in the hydrogen liquefier at Cambridge, we had to fetch the liquid hydrogen necessary for our experiments from Oxford. The ride back was a hair-raising experience. My brother had to hold a five-liter Dewar vessel in his lap in the rumble seat while the liquid hydrogen sloshed around wildly. 

Hydrogen liquefied at 20° K., a temperature but twenty degrees above absolute zero. This is not a record low liquefaction point, by any means. In the 1890s, the inert gases had been discovered (see page 147), and one of these, helium, liquefied at a still lower temperature. 

Valenti G, Macchi F (2008) Proposal of an innovative, high efficiency, large-scale hydrogen liquefier. Int J Hydrogen Energy 33 3116-3121... 

Natural gas is primarily methane, CH4. Petroleum is a mixture of hydrocarbons (compounds of carbon and hydrogen). Liquefied petroleum gas (LPG) is a mixture of propane (CsHs) and butane (C4H10). 

Refrigeration systems based on the Joule-Thomson effect have lower thermodynamic efficiencies than those based on refrigeration systems with expansion engines. Most small laboratory and commercial hydrogen liquefiers, however, (not including those depending upon helium expansion cycles) utilize Joule-Thomson refrigeration because of simplicity and compactness [5],... 

The Bakersfield plant is considerably more than a hydrogen liquefier. First, it provides a continuous supply of liquid hydrogen thus, the plant must operate night and day. For operations of this kind there are two liquefiers and three purifiers (see Fig. 6), although for plant capacity only one purifier and one liquefier are needed at a time. The two extra purifiers and extra liquefier are available so that repairs may be made while the plant is in operation. 

W.A. Wilson and D. H. Weitzel, "Vapor phase ortho-para conversion in the large CEL-NBS hydrogen liquefier," Advances in Crvosenic Engineering, Vol. 3, K. D. Timmerhaus (ed.). Plenum Press, Inc , New York (1960). 

The presentation of the N2 data is intended to characterize the silica gel used in these tests. The fact that this gel is a high capacity grade identical to that used in the purifier units of the National Bureau of Standards hydrogen liquefier also allows a comparison of experimental and predicted capacities for N2 and CH4 with observed purifier capacities for N2. 

If one assumes that the "adsorption enhancement factor" is a function of temperature and total pressure only at these low concentrations it is possible to calculate the change in capacity with impurity level for any selected operating pressure. The "impurity" isotherms calculated for CH4 in H2 and N2 in H2 at 60 atm and 76°K are compared in Fig. 6. The experimental points shown are the results of purifier saturation tests in the National Bureau of Standards hydrogen liquefier for N2 in H2 at the same adsorption pressure and temperature [1]. The agreement between predicted and experimental capacities for N2 at these conditions is quite satisfactory. There appears to be no reason why the predicted capacities for CH4 would not be just as good. 

Answer by author The comment is well taken. The authors would like to re-emphasize that the capacities predicted from these experimental data are in close agreement with observed purifier capacities for nitrogen in the National Bureau of Standards hydrogen liquefier. 

Mobile Liquid Hydrogen Plant (1) 324 Performance of NBS Hydrogen Liquefier Plant (1) 329... 

Hydrogen-Helium Liquefier (2) 8 A New Arrangement for Ortho-Para Conversion of Liquid Hydrogen in the Large CEL-NBS Liquefier (2) 19 Vapor Phase Ortho-Para Conversion in the Large CEL-NBS Hydrogen Liquefier (3) 85... 

Vapor Phase Ortho-Para Conversion in the Large CEL-NBS Hydrogen Liquefier (3) 85... 

Hydrogen can be liquefied provided the liq-uefier feed is very high purity hydrogen. Liquefied hydrogen has a minimum purity of 99.995 percent. Para hydrogen liquefies at -423.2°F (-252. 9°C), and at that temperature any contaminant (other than helium), if present in the liquefication feedstock, can solidify and plug the liquefier. 

Fuel Gases—gases intended for burning in air or oxygen. Examples are acetylene, butane, hydrogen, liquefied petroleum gas (LPG), methyl acetylene-allene mixture (MAPP gas), propane, and other hydrocarbons. 

Copper Naphthenate Oils Edible. Palp Oils Edible. Palp Oils Edible, Tucup Phthalic Anhydride Polymethylene Polyphenyl Isocyanate P-Dichlorobenzene P-Dichlorobenzene P-Dichlorobenzene Paraformaldehyde Hydrogen, Liquefied Cipentene P-Dichlorobenzene Anthracene Parathion, Liquid Methyl Parathion P-Xylene... 

Hydrogen, Liquefied — Fire Hazards Flash Point (deg. F) Not pertinent Flammable Limits in Air (%) 4.0... 

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