Re: GAS-L: maximum pressure and the wooden "battery"

[Peter Singfield <snkm@btl.net>]

Arnt --

Metals oxide reduction/oxidation cycles are very well established!

Thermite is a classy example -- iron oxide & aluminum

So -- steam/iron = iron oxide + H2

Aluminum and iron oxide = aluminum oxide -- pure iron -- and a lot of heat.

The problem is always reducing the oxide back to the pure metal -- in this
example -- reducing back to aluminum.

But in the tin molten metal case -- it is "good"

Try getting rid of the oxide in aluminum with any kind of efficiency!

Further -- the "chemical" required -- CO -- is exactly what we have in our
pocket!

This reaction is very controllable. And runs to completion -- extremely
high purity H2 requiring no further purification -- and at extremely high
efficiencies.

Your carbon cycle is a nightmare -- comparatively. Sure -- it is there in
huge gasifiers -- doing a "little" -- as in "maybe".

The tin metal bath is very positively reversible -- over and over -- under
very compact conditions -- and very energy neutral.

>...which can be rewritten:
>
>H2O + Sn + 2 CO + SnO2 <-> SnO2 + H2 + Sn + 2 CO2

Sure -- if one puts CO there during the "steam" cycle -- but why in the
world do that!!

It is a dual cycle deal Arnt -- you mean you really missed that??

Cycle one:

Pure tin -- pass through pure steam -- result -- pure H2

There is no problem producing pure steam.

You turn off the steam well before H2O no longer reacts with Zn -- so no
H2O crosses over.

Ergo -- no H2O contaminating the "pure" H2 product.

Cycle Two:

Once a set amount of ZnO2 is reached in the bath -- you turn off the steam
-- and pass through the gas product that has been stripped of H2 in the
membrane separator.

The feed gas that is used to "reduce" the metal oxide back to a pure metal
is the exhaust from the membrane separator.

(The feed gas to the membrane separator can be product from a biomass steam
reformation device -- or from even a biomass partial combustion gasifier)

This "gas" exhaust from the membrane separator can be a combination of
atmospheric (mostly N2) gas, residual H2, CO2, CO. 

The ones we do not want there is O2 or H2O -- but small levels will not
effect this reduction to a great extent anyway! There is no need to make
the entire metal bath pure -- just to recover sufficient ZN from ZnO2 to
repeat a cycle.

The CO reacts with the ZnO2 as above -- reducing the oxide to pure tin
again -- the rest of the gasses pass through. Some residual side action due
to contaminants of O2 and H2O may create new ZnO2 -- but the net result
will be a lot of the ZnO2 back as Zn. And a little extra H2 at the exhaust.

The Gas exhaust products -- still containing some hydrogen (and some CO) as
well as the rest -- can either be used as a very low value fuel for the
catalytic converter -- or passed through the membrane separator again -- 

What is the purpose of all this??

Maximizing production of H2 at extremely high product efficiencies to run
an H2 fuel cell!!

OK -- I've showed you mine -- using a tin bath --

Now -- you show me yours -- using a hot charcoal bed?? Show me how you can
maximize pure H2 using a hot charcoal bed??? And at high over all
efficiencies!!

In the system I outline -- no need for a flywheel device -- you can put
that where the sun don't shine! Cause all of the above would fit under the
hood -- the big advantage of a pressurized gasification system -- and you
could feed any biomass fuel you want into the "tank" -- along the lines of
the MaClaren in Back to the Future -- or what ever.

You got Urls for yours???

By the way folks -- Bright Star found 40% humidity the idea rate for self
steam reforming biomass.

That Url is long gone -- but I did save a copy!! Very specific -- very
enlightening. They to used catalytic heating -- and membrane separators.

What they lacked -- and what would have made the big difference -- is the
tin metal bath deally!

I hope this is not lost on this list?? Re: The vital importance of
converting CO to H2 at extremely high efficiency. It makes or breaks the
economics of gasifying any hydrocarbon for purposes of supplying H2 to a
fuel cell.


Peter

At 05:24 PM 2/4/2002 +0100, you wrote:
>On Monday 04 February 2002 02:00, Peter Singfield wrote:
>> Arnt ---
>>
>> You mean:
>>
>> 2(H2O) + C = CO2 + 2(H2)
>>
>> CO2 + 2(CO) = C + 2(CO2)
>
>..nope, I meant the unbalanced:
>> >>  H2O  +  Sn     ------> SnO2 + H2
>> >>  SnO2 + 2CO  ----->  Sn + CO2
>
>...which can be rewritten:
>
>H2O + Sn + 2 CO + SnO2 <-> SnO2 + H2 + Sn + 2 CO2
>
>> I doubt this reaction is as "stable" as the tin example.
>
>.."gas only" does not work, and the coal bed is "stable" and 
>self-regulating, run my way.  But this?
>
>..numbers for the tin bath?
>
>> As in easily reproducible with near total completion -- time after
>> time -- etc.
>>
>> Further -- your looking at an all gas reaction in that example.
>>
>> The tin metal bath is liquid with an amount a SnO2 in it -- great
>> heat sink -- and easy to manipulate.
>>
>> For the curious -- the tin metal bath "converter" is at:
>>
>> http://www.alchemix.net/products.htm
>
>..sexy.
>
>> Bruno -- here is you chance to check it out!
>
>..my mistake, we're off-list.  ;-)
>
>> Peter
>>
>> At 01:14 AM 2/4/2002 +0100, you wrote:
>> >On Sunday 03 February 2002 20:06, Peter Singfield wrote:
>> >> Fine tuned balancing can be achieved by using a tin metal bath and
>> >> this reaction -- which is energy "neutral":
>> >>
>> >>  H2O  +  Sn     ------> SnO2 + H2
>> >>  SnO2 + 2CO  ----->  Sn + CO2
>> >
>> >..this _tin = Sn_ metal bath replaces our trusty good old
>> >carbon bed in our thermochemical gasification magic?????
>
>-- 
>..med vennlig hilsen = with kind regards from Arnt...  ;-)
>
>  Scenarios always come in sets of three:
>  best case, worst case, and just in case.
>
>

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