Re: GAS-L: The "Hydrogen Economy": Bleak or Bright?

[Peter Singfield <snkm@btl.net>]

At 05:15 PM 11/22/2002 +0800, Marc de Piolenc wrote:
>
>
>Peter Singfield wrote:
>
>> There is -- however -- a really cute method of converting synthesis gas to
>> almost pure H2 product -- at great efficiencies -- using a liquid tin metal
>> bath.
>
>I know you've mentioned this process before on the list, Peter, but I
>can't find where the deuce I saved it. This may be one of the files that
>was a casualty of my recent "simple" hard drive upgrade.
>
>Can you dig into your archives and repost? I know the crest archives are
>nominally available, but access is so slow from here that for practical
>purposes the messages might as well be on the Moon.
>
>Best,
>Marc
>
>

Dear Marc;

That specific topic went off list at that time. And it is buried in my
archives of personal communications.

Basically -- 

You pass steam through a liquid metal bath of zinc. Zinc oxide and pure H2
are the results.

The zinc is regenerated back from zinc oxide to pure metal by sparging with
CO. That resulting in CO2 as the off-gas -- and pure zinc in the bath. Of
course -- there is no need to run to "completion" -- just establish rich
enough pure zinc levels for the next steam pass.

Both the H2 and CO2 are relatively pure.

The steam to H2 is endothermic.

The CO to Zinc and CO2 -- exothermic.

So the energy use is balanced well.

We were kicking around the idea of using this process to enrich producer
gas with more hydrogen with the idea of running a fuel cell.

Apparently N2 is not a problem for fuel cells -- but CO2 and CO are??

The other obvious use of such a device is to balance the Fischer Tropsch
reaction. An easy way to maintain proper mix of CO and H2 -- for efficient
synthesis.

It is all highly theoretical --

This is the Url:

http://www.alchemix.net/products.htm

(If no longer valid -- tell me -- I have this site archived and can post
the text)

They make an interesting statement there -- that should be a guide line for
further inovation in the biomass to energy field of endeavor:

"When hydrocarbons are placed into a pure hydrogen environment at high
temperature they will very quickly transform into methane gas. This is true
because methane is the most stable hydrocarbon and when less complete
hydrocarbons are exposed to unlimited hydrogen atoms they will add as many
to their structure as are required to get to methane."

A new-wave biomass gassification process??

I realize methane is not the kind and gentle gas fuel -- but it will run IC
engines much better than producer gas -- and also fire boilers well. Can be
stored (compressed) to an extent to allow a better control function of
power supply.

Also -- of interest -- along the lines of molten metal baths and separate
-- controlled -- flows of H2 and CO:

Search for patent:

6,110,239 

At:   http://patft.uspto.gov/

Have appended the Abstract --

Also -- this patent is of interest:

5,537,940 -- have appended abstract as well.

In the last two example -- the "working-fluid" is:

"Molten metal 56 is disposed within reactor 12. In one embodiment, molten
metal 56 comprises a metal having a free energy of oxidation, at operating
conditions of system 10, which is greater than the free energy for
conversion of atomic carbon to carbon monoxide. Examples of suitable metals
include iron, chromium and manganese. Molten metal 56 can include more than
one metal. For example, molten metal 56 can include a solution of miscible
metals, such as iron and chromium."

and:

"Suitable metals are those with melting points within the operating
conditions of the system. It is preferred, for example, to run system 10 in
a temperature range of from about 1300.degree. C. to about 1700.degree. C."

The liquid tin bath is especially interesting -- lower temperatures --
making it more easily scalable -- down!

Many might find this all over challenging -- but I personally worked with
liquid metal baths many years ago -- and find it less of a "threat" than most.

I imagine scrap cast iron would work for the second two??

This is SciFi -- maybe -- but definitly not Fantasy.

Hey -- I'm just trying to get people to wake up and think!! If that can
only be accomplished by moving off-shore from the Induatrialized nations --
so be it!

Belize is ideally situated for a serious Shangrila style "retreat". The
abondoned Libertad Sugar Factory with it's 3500 acres of estate lands --
situated on a great inland river -- barge harbor giving access to the
oceans -- sheltered from hurricanes -- no earthquakes -- no volcanoes -- 

Existing furnace capacity for 10 megs of power using combustion biomass --
now!!

OK -- that was "Fantasy" ---

But don't we all "wish"??

Peter



******appended 6,110,293 - Abstract***************

----------------------------------------------------------------------------
----
United States Patent  6,110,239  
Malone ,   et al.  August 29, 2000  

----------------------------------------------------------------------------
----
Molten metal hydrocarbon gasification process 


Abstract
A process in which a high-purity, high-pressure hydrogen-rich gas stream
and a high-purity, high-pressure carbon monoxide-rich gas stream are
simultaneously produced separately and continuously using a molten metal
gasifier that contains at least two zones, thereby avoiding the need to
separate or compress the gases in down-stream equipment. In one version of
the process, the steps comprise (a) introducing a hydrocarbon feed into a
molten metal bath beneath the molten metal surface in a feed zone operating
at a pressure above 5 atmospheres absolute, and decomposing the hydrocarbon
feed into hydrogen, which leaves the feed zone as a hydrogen-rich gas, and
into carbon, which dissolves in the molten metal and increases the carbon
concentration, but controlling the carbon concentration to at or below the
limit of solubility of carbon in the molten metal, (b) transferring a
portion of the molten metal from the feed zone to another molten metal
oxidation zone operating at a pressure above 5 atmospheres absolute into
which an oxygen-containing material is introduced beneath the molten metal
surface to react with a portion of the carbon to form a carbon
monoxide-rich gas which leaves the oxidation zone, wherein the carbon
concentration in the molten metal is controlled so that it does not reach
the concentration at which the equilibrium oxygen concentration would
exceed its solubility limit in the molten metal and a separate iron oxide
phase would accumulate, (c) transferring at least a portion of the molten
metal which has a lower carbon concentration from the oxidation zone back
to the feed zone, and (d) passing said separate high-pressure, high-purity
hydrogen-rich and carbon monoxide-rich gas streams out of their respective
zones, removing entrained dust and cooling the gas streams to temperatures
suitable for use in industrial processes. 


----------------------------------------------------------------------------
----
Inventors:  Malone; Donald P (Grayson, KY); Holcombe; Thomas C (Somerville,
NJ); Miller; Charles B (Ashland, KY)  
Assignee:  Marathon Ashland Petroleum LLC ()  
Appl. No.:  867703 
Filed:  May 30, 1997 

Current U.S. Class: 48/198.2; 48/92  
Intern'l Class:  C01B 003/24 
Field of Search:  48/92,198.2  



********appended #2****************

       ( 3 of 5 ) 

----------------------------------------------------------------------------
----
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. 


----------------------------------------------------------------------------
----
Inventors:  Nagel; Christopher J. (Wayland, MA); Sparks; Kevin A.
(Scituate, MA); McGeever; Casey E. (Allison Park, PA)  
Assignee:  Molten Metal Technology, Inc. (Waltham, MA)  
Appl. No.:  351382 
Filed:  January 6, 1995 
PCT Filed:  June 8, 1993  
PCT NO:  PCT/US93/05398  
371 Date:  January 6, 1995  
102(e) Date:  January 6, 1995  
PCT PUB.NO.:  WO93/25277 
PCT PUB. Date:  December 23, 1993 



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