[Gasification] Fe + H2O = FeO + H2 -- reply 2

[Peter Singfield]

At 05:14 PM 12/1/2006 -0500, you wrote:
>Dear List,
>
>Interesting information at below link:
>http://gasifiers.bioenergylists.org/?q=node/218
>
>
>Snip:
>"The above equation tells us that with steam and hot or molten iron we can
>make H2 with rust being the byproduct. This rust can be converted back to
>iron. Check out the below links for more information."
>
>
>Jeff

OK -- found the more exact reference:

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=/netahtm
l/search-adv.htm&r=3&f=G&l=50&d=PALL&p=1&S1=4,496,369&OS=4,496,369&RS=4,496,
369

United States Patent  5,537,940  
Nagel ,   et al.  July 23, 1996  

----------------------------------------------------------------------------
----
Method for treating organic waste 


Abstract
Organic waste is treated in a molten metal bath to sequentially form
enriched hydrogen gas and carbon oxide gas streams. The method includes
introducing organic waste to a molten metal bath in the absence of a
separate oxidizing agent and under conditions that will decompose the
organic waste. As a consequence of this decomposition, an enriched hydrogen
gas stream is generated and the molten metal bath becomes carbonized.
Thereafter, an oxidizing agent is added to the carbonized molten metal bath
to oxidize the carbon contained in the carbonized molten metal bath.
Reaction of the oxidizing agent with the carbon causes formation of a
carbon oxide that escapes from the bath as an enriched carbon oxide gas
stream, thereby decarbonizing the molten metal bath. 

BACKGROUND OF THE INVENTION 

Disposal of organic wastes in landfills and by incineration has become an
increasingly difficult problem because of diminishing availability of
disposal space, strengthened governmental regulations, and the growing
public awareness of the impact of hazardous substance contamination upon
the environment. Release of hazardous organic wastes to the environment can
contaminate air and water supplies thereby diminishing the quality of life
in the affected populations. 

To minimize the environmental effects of the disposal of organic wastes,
methods must be developed to convert these wastes into benign, and
preferably, useful substances. In response to this need, there has been a
substantial investment in the development of alternate methods for suitably
treating hazardous organic wastes. One of the most promising new methods is
described in U.S. Pat. Nos. 4,574,714 and 4,602,574, issued to Bach and
Nagel. The Bach/Nagel method for destroying organic material, including
toxic wastes, involves decomposition of the organic material to its atomic
constituents in a molten metal and reformation of these atomic constituents
into environmentally acceptable products, including hydrogen, carbon
monoxide and/or carbon dioxide gases. 

SUMMARY OF THE INVENTION 

The present invention relates to a method for treating organic waste in
molten metal contained in a vessel to sequentially form enriched hydrogen
gas and carbon oxide gas streams. 

In one embodiment, an organic waste containing hydrogen and carbon is
introduced into molten metal, without the addition of a separate oxidizing
agent and under conditions sufficient to decompose the organic waste and to
generate an enriched hydrogen gas stream and to carbonize the molten metal.
The enriched hydrogen gas stream is substantially removed from the vessel.
Thereafter, a separate oxidizing agent is added into the carbonized molten
metal to oxidize carbon contained in the carbonized molten metal to form an
enriched carbon oxide gas stream. The enriched carbon oxide gas stream is
substantially removed from the vessel. 

In another embodiment of the invention employed to increase the amount of
carbon dioxide to carbon monoxide in the enriched carbon oxide gas stream,
the organic waste is introduced into molten metal contained in a vessel
which comprises two immiscible metals wherein the first immiscible metal
has a free energy of oxidation, at the operating conditions, greater than
that for oxidation of carbon to carbon monoxide and the second immiscible
metal has a free energy of oxidation, at the operating conditions, greater
than that for oxidation of carbon monoxide to carbon dioxide, without the
addition of a separate oxidizing agent and under conditions sufficient to
decompose the organic waste and to generate an enriched hydrogen gas stream
and to carbonize at least one of the two immiscible metals. The enriched
hydrogen gas stream is substantially removed from the vessel. Thereafter, a
separate oxidizing agent is added into the carbonized molten metal to
oxidize carbon contained in the carbonized molten metal to generate an
enriched carbon monoxide and carbon dioxide gas stream having a
significantly increased ratio of carbon dioxide/carbon monoxide compared to
that produced in molten iron under the same conditions and decarbonizing
the molten metal. The enriched carbon oxide gas stream is substantially
removed from the vessel. 

This invention has the advantage of treating organic waste to form an
enriched stream of hydrogen gas and a separate enriched stream of carbon
oxide gas, such as carbon monoxide or carbon dioxide or both. Enriched
hydrogen and/or carbon oxide gas streams are often desired. For example, an
enriched stream of hydrogen gas is particularly useful in the synthesis of
ammonia or oxoalcohol and in hydrogenation or desulfurization processes.
Hydrogen is also an excellent "clean" or "greenhouse gas free" fuel.