Hydrogen pumping

LIQUID HYDROGEN PUMPING PROCEDURES SHUT DOWN... 

Hydrogen pumps — are electrochemical devices with proton-conducting - solid electrolytes, where hydrogen is transported through a dense electrolyte membrane by an applied electrical field. The device... 

The small forecourt size, which could be a single hydrogen pump at an existing station, will serve 150 500 cars with a hydrogen production rate of 30,000-100,000-kg hydrogen year"1. 

Hydrogen pump prices for second generation, Year 31-Year 60, electrolytic H2 production are reduced to 3.90- 3.40/kg for 10% to 14% efficient PV modules respectively in the case of a thirty-year PV module operating life and to 3.06- 2.73/kg for 10% to 14% efficient PV modules respectively in the case of a sixty-year PV module operating life. A summary of H2 pump prices is presented in Fig. 10. 

While this method is capable of making thick and ductile metal membranes, some technical problems may be encountered such as hydrogen pumping which requires annealing the deposited membranes under vacuum to ensure their ductility and difficulty in controlling the thickness over a wide range of alloy composition. 

The unusual interaction of hydrogen with palladium-based membrane materials opens up the possibility of oxidative hydrogen pump for tritium recovery from breeder blankets. The feasibility for this potential commercial application hinges on the hot-fusion and cold-fusion technology under development [Saracco and Specchia, 1994]. At first, Yoshida et al. [1983] suggested membrane separation of this radioactive isotope of hydrogen followed by its oxidation to form water. Subsequently, Hsu and Bauxbaum [1986] and Drioli et al. [1990] successfully tested the concept of combining the separation and reaction steps into a membrane reactor operation. 

Finally the possibility to utilize electrolysers to elevate hydrogen pressure and recirculate it inside anode flow fields in H2FCS power sources has been recently considered [10]. This electro-chemical approach for hydrogen pumping could be effected with an external additional smaller PEMFC component, connected to the stack devoted to electric power generation, or alternatively using in electrolysis mode a group of cells of the main PEMFC stack. 

Barbir F, Gorgun H (2007) Electrochemical hydrogen pump for recirculation of hydrogen in a fuel cell stack. J Appl Electrochem 37 359-365... 

Oxygen and Hydrogen Pumping, Water Vapor Electrolysis... 

Figure 12.12 Hydrogen pumping using proton-conducting ceramics. 

Although cryogenic fuels are difficult to handle, a self-service liquid hydrogen pumping station was built decades ago at Los Alamos National Laboratory. It was shown to be feasible for refueling vehicles over an extended period of time without any major difficulties. 

Fig. 1. Change of resistance of a transparent nickel film with the adsorption of hydrogen at room temperature. P = hydrogen pumped off.

INLET DESIGN CONSIDERATIONS FOR A LIQUID-HYDROGEN PUMP... 

Inlet Design Considerations for a Liquid-Hydrogen Pump... 

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