Hydrogen generator
A hydrogen generator is formed of a strip of corrugated material that has been folded back and forth upon itself to define a monolith having multiple fluid flow regions. At least one of these regions is used for combustion, and at least one of these regions is used for steam reforming. Water is introduced into another fluid flow region, so as to receive heat from products of combustion, and to be converted into steam. The steam is directed into one or more regions used for steam reforming, so as to produce hydrogen for use in a fuel cell. In its more general form, the invention includes a compact heat exchanger, formed of a strip of corrugated material that has been folded back and forth upon itself, the heat exchanger being capable of transferring heat among three or more fluid streams.
1. A method of making hydrogen, comprising:
a) directing a hydrocarbon fuel into a combustion region of a monolith formed by folding a corrugated strip back and forth upon itself to define a plurality of fluid flow regions, said plurality of fluid flow regions comprising a first fluid flow regions, second fluid flow region and a third fluid flow region, said first, second and third fluid flow regions being different fluid flow regions, said first fluid flow region defining the combustion region, the combustion region having a combustion catalyst,
b) directing a hydrocarbon fuel into said second fluid flow region which defines a steam reforming region, the steam reforming region having a steam reforming catalyst,
c) directing a stream of water into said third fluid flow region, while directing products of the combustion region so as to be in heat exchange relationship with said stream of water, so as to produce steam, and
d) withdrawing hydrogen from said steam reforming region.
2. The method of claim 1 , further comprising the step of passing an electrical current through the strip so as to heat the strip.
3. The method of claim 1 , further comprising directing air into said combustion region.
4. The method of claim 3 , further comprising directing the air through a fluid flow region which is in heat exchange relationship with products of said combustion region.
5. The method of claim 1 , further comprising directing steam and hydrocarbon fuel into a fluid flow region that is in heat exchange relationship with products of said steam reforming region.