Re: GAS-L: Gasification terminology

[Peter Singfield <snkm@btl.net>]

Dear Harry, Tom and All:

Regarding your statement:

>The above endothermic reaction results in real processes 
>being rather inefficient, usually about 50%.

How so?? The energy required to fuel this endothermic reaction is
"invested" in a higher btu value product.

If you check out the values carefully -- there is no theoretical loss.

Now -- please stop and think about this -- how could there be??

(Unless you have a micro-black hole laying around)

The converse of a perpetual motion machine??

The loss in efficiencies is do to poor process design.

As example -- if you used electric resistance heating to fuel the
conversion -- well over 95% (probably over 99%) of the energy in -- will be
accounted for in the increased btu value of the gas product out.

(A simple experiment to perform -- why don't you try it??)

Actually -- this subject has been covered to great depth on this same list
in the recent past. 

Hint -- notice how the car makers are using catalytic converters to fuel
their reforming reaction. That is as close as one can get to resistance
electrical heating in thermodynamic investment technology -- no flue gases!
(or extremely little comparatively)

You can't simply make energy disappear -- or get lost.

In the "old" reforming gasifiers -- it was flying to the skies up the stack
-- with maybe a little percentage recovered from that "waste" heat to power
a steam turbine and extract power.

I can't help but notice the fixation of this list on WWII gasifiers and the
complete ignorance of the new wave gasifiers (yes "GASIFIERS") being
researched and introduced for automotive purposes. 

That is the fuel cells cars ----

It is ok to have historical interest -- or historical perspective -- but
this list is about gasification technology.

How can it continually ignore progress in this field of endeavor??

Fuel cell technology is well married to reformation gasification. Why
ignore this facet of technology??

There is no scientific reason that present car fuel system technology can
not be adapted to run on coal or biomass. In a more efficient manner --
more compact -- and producing much more power -- than WW II partial
combustion gasifiers.

We simply have to be able to relate to what we observe -- not ignore what
our ears and eyes are telling us -- because of a mental confusion -- that
is limited to not seeing beyond WWII technology.

One last hint -- the CO in the mentioned H2 reaction products is utilized
to operate the catalytic converter -- to fuel to reaction.

Also -- you can straight convert excess CO from the above to H2 using the
tin liquid metal bath -- with extremely high efficiencies.

If they can do all this in a car -- certainly they can do it in a coal
fueled power plant??



Peter Singfield / Belize

At 11:02 PM 1/29/2002 EST, you wrote: 
>>>>
Dear Harry and All:  

Harry's example below of the water gas reaction with carbon (coal) is
certainly one example of gasification.  Since coal is 70-90% fixed carbon,
many people think that is the only "gasification" reaction.   

However, biomass is only 20-30% fixed carbon, so the million gasifiers of
WWII were primarily pyrolytic and only secondarily carbon reactions..... 

So our gasification umbrella is quite large... 

Yours truly,      TOM REED          BEF GASWORKS 

In a message dated 1/28/02 4:24:13 AM Mountain Standard Time,
Harry.Parker@ttu.edu writes: 



Hello all, 
  
We have to get our terms clarified.  To me gasification is the reaction of
carbon with steam, but some of you may call it the water gas shift reaction
too. 
  
C + H2O  <---> CO + H2   
  
This reaction is highly endothermic since you are "unburning" water.    The
combustible hydrocarbons you get from organic matter pyrolysis are a bonus.   
  
<><><>
  
On another topic, we need to keep asking the proponents of fuel cells where
their H2 comes from.  The above endothermic reaction results in real
processes being rather inefficient, usually about 50%.  Methane reforming
is endothermic too. 
  
CH4 + H2O  ---> 3H2 + CO  
  
Harry 
  







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