Hydrogen release

Heat is produced during hydrogen absorption, and must be suppHed during its release. The weight of hydrogen that can be released from the hydride, about 1.5 wt %, requires approximately the same volume as Hquid hydrogen, but the hydride is much heavier. The hydrogen released from a hydride has a... 

Nascent atomic hydrogen released at metal surfaces by chemical reactions between the process environment and the metal (corrosion or cathodic protection reactions)... 

Nascent atomic hydrogen released by a process reaction such as catalytic desulfurization... 

Linney (1990) summarized the liquid hydrogen release tests performed by A. D. Little Inc. in 1958, by Lockheed in 1956-1957, and by NASA in 1980. Both high- and low-pressure releases were studied. None of the tests resulted in a blast-producing explosion. 

Corrosion processes in the boiler section generate hydrogen—this hydrogen release is regularly measured in very high pressure boilers as it can be indicative of the rate of corrosion taking place... 

Fig. 3.5 Potential vs. pH diagram for the CdTe-H20 system at 25 °C. Solid CdTe is thermodynamically stable over the entire pH range. Consequently, CdTe does not hydrolyze at any H and OH activities of practical interest. In acidic solutions, the only process accompanying cathodic CdTe polarization is hydrogen release. Therefore, in the region of cathode potentials, CdTe is a sufficiently stable electrode material from the electrochemical point of view. The -1.35 V potential is the lowest limit of stabihty. Below this limit, CdTe corrodes in the whole pH range e.g., for pH < 2.8, H2Te vapor is produced at -1.25 V. For pH > 2.8, diteUuride or telluride ions are formed with disintegration of the compound. (With kind permission from Springer Science+Business Media [82])...

DHN. Apparently DHN both thermally dehyrogenates to naphthalene and disproportionates to Tetralin and naphthalene. In all of the runs, there was a sizable amount of hydrogen released when the reactors were opened. When DHN was heated at 450°C for either 15 or 180 minutes, the ratio of naphthalene to etralin was 1.8. Increased methyl indan formation occurred with time. With the introduction of dibenzyl, the anticipated [2] increased isomerization of T etralin to methyl indan occurred. These results suggest that the rearrangement of hydroaromatics does not proceed through the dihydro-... 

Acceleration/handling Similar to or better than current ICE vehicles Minimal weight (high gravimetric energy density) Rapid hydrogen release kinetic properties... 

Low heat of formation to minimize the energy necessary for hydrogen release and low heat dissipation during the exothermic hydride formation... 

LH2 spills. Liquefied hydrogen releases yield dramatically larger volumes of combustible clouds (1 L of liquid produces 851 L of gas on evaporation). Therefore, the consequences of a fire or explosion are more extensive than that of a pressurized hydrogen release. 

Event tree analysis adapted to accidental hydrogen releases. (From Rigas, F. and Sklavounos, S., lnt. ]. Hydrogen Energ., 30,1501,2005. With permission from International Association of Hydrogen Energy.)... 

Since a catastrophic rupture is rather unlikely, failure modes resulting in large or slow hydrogen release have been identified experimentally. Countermeasures to avoid the preceding failure modes could be for instance... 

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