Hydrogen generation system

Chemical apparatus and process disinfecting – deodorizing – preser – Chemical reactor – Including solid – extended surface – fluid contact reaction...

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C422S236000, C048S118500, C423S657000, C423S658200

Reexamination Certificate

active

06790416

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to hydrogen generation, and more particularly, to a system for the catalytic hydrolysis of sodium borohydride.
As is well known, fuel cells combine hydrogen and oxygen to generate electricity. In some applications, it is necessary to precisely and accurately meter hydrogen, on demand, to a fuel cell to control the electrical output. An example is a miniaturized PEM fuel cell.
It is also known that hydrogen can be evolved from reactive solutions such as by the catalytic hydrolysis of sodium borohydride, NaBH
4
. A prior art approach for generating hydrogen on demand for use in fuel cells utilized pumps to deliver an aqueous solution of sodium borohydride to a catalyst bed. There are, however, problems with this approach. A stoichiometric sodium borohydride aqueous solution has high viscosity that makes it difficult to pump in a precise manner. Sometimes nonreactive chemicals were added to lower the viscosity or a nonstoichiometric ratio was used to aid pumping. Alternatively, a strong base, such as sodium hydroxide, was added to the sodium borohydride solution in an effort to stabilize it. The resulting solution was then caustic making handling more difficult.
Another problem with the prior art approach is that the hydrolysis reaction generates a by-product, sodium metaborate, NaBO
4
, that must be removed. Sodium metaborate tends to pick up water and to gel when allowed to cool. Its presence hinders access to the catalyst and makes the water needed for the reaction less available. If this reaction product is allowed to cool and gel, it cannot be readily pumped away.
Another approach to evolving hydrogen from sodium borohydride is to heat the material to generate hydrogen as needed. A problem with this approach is high parasitic loss and another problem may be material compatibility issues.
SUMMARY OF THE INVENTION
The hydrogen generation system of the invention includes a source of sodium borohydride along with a source of water and a catalyst such as ruthenium. Structure is provided for contacting sodium borohydride, water and catalyst to release hydrogen and to move the reactants into and away from a reaction zone.


REFERENCES:
patent: 4155712 (1979-05-01), Taschek
patent: 4261955 (1981-04-01), Bailey, Jr. et al.
patent: 5514353 (1996-05-01), Adlhart
patent: 5976725 (1999-11-01), Gamo et al.
patent: 6592741 (2003-07-01), Nakanishi et al.
patent: 2001/0045364 (2001-11-01), Hockaday et al.
patent: 2003/0118504 (2003-06-01), Mazza et al.
patent: 10045669 (2001-04-01), None
patent: 1170249 (2002-01-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Hydrogen generation system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hydrogen generation system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrogen generation system will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3233559

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.