Slush hydrogen

Tank (containing LOX/LH, propellant) by 13 percent, and NASA is willing to make it 26 percent lighter. Another solution is the hydrogen slush, which is liquid hydrogen hyper cooled almost to the point of solidification (—259° Celsius compared to —252° Celsius for normal LH,). Due to 15 percent greater density, hydrogen slush occupies lesser volume and has lower evaporation losses. 

H. M. Roder, The Thermodynamic Properties of Slush Hydrogen and Oyygen, PB Rep. No. PB-274186, National Technical Information Service,... 

R. O. Voth, J. D. Siegworth, J. F. Welch and M. J. Hi2a, Process Design Criteria, Data and Metrology Related to Slush Hydrogen Technology, NASA Tech. Memo 1006, NASA Langley Res. Cntr.,Mar., 1987. 

After leaving the reactant zone, the product stream enters a 0.5 in diameter FEP tube cooled by either a salt-ice bath or acetone-carbon dioxide slush bath [16]. The gas mixture was scrubbed in a soda-Hme tower. Hydrogen fluoride was trapped by adding sodium fluoride to the reaction mixture or simply adding water. Then, the product solution was extracted with dichloromethane, washed with aqueous... 

This procedure differs from those outlined for the bromo and chloro derivatives in that an appreciable excess of (dimethyl-amino) diflu orophosphine cannot be used because it is difficult to separate from iododifluorophosphine by fractional condensation. Typically, (dimethylamino)difluorophosphine (6.38 mmol) and hydrogen iodide (12.76 mmol) are condensed into a 500-ml. reaction bulb and allowed to warm slowly to 25°. As reaction ensues, f the white solids are discolored by formation of red phosphorus triiodide which probably results from a disproportionation 3PF2I —> 2PF3 + PI3. Thus, when the products are separated by fractional condensation through —126° (methylcyclohexane slush) to —196°, an appreciable amount of... 

Carney (Ref 11) reviews the props of slush hydrogen and points out its desirability as a space vehicle proplnt fuel because of wt savings on long-term storage. Slush hydrogen is a fluid mixt contg solid H2 (by wt) 50% in liq H2... 

Hydrogen Handling Hazards. The principal hazards associated with handling hydrogen as a gas or a liquid or a slush (mixture of solid and liquid hydrogen) are related to... 

Low temperatures of liquid or slush hydrogen adversely affecting the containment materials subjected to the low temperatures... 

Hybrid storage of hydrogen, where a combination of technologies is applied, such as the storage of hydrogen as slush or as a supercritical fluid, is briefly mentioned. 

Haberbusch, M. and McNelis, N. (1996) Comparison of the Continuous Freeze Slush Hydrogen Production Technique to the Freeze/Thaw Technique. NASA Technical Memorandum 107324. 

Ohira, K. (2004) Development of density and mass flow rate measurement technologies for slush hydrogen. Cryogenics, 44, 59-68. 

Hydrogen chloride is a common impurity which can be almost entirely removed by using a —160° trap (isopentane slush ... 

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