[Gasification] Coal V Wood V Charcoal gasification.

[doug.williams]

Peter,

Thank you for slowing down a bit, it helps slow readers like me(:-)


> Ergo -- our discussion a while back in regards to going to charcoal only
> gasifiers -- thus more easily achieving a clean product gas -- for one
> thing -- more uniform production - -for another.


When I post responses to questions posted on this Forum, the answer is 
addressed to the uniformed questioner, usually some one who has just 
discovered gasification for the first time. To anyone else who has plenty of 
technical capability, it surely is old hat stuff, but a casual comment can 
trigger a whole lot of very interesting discussion around what we do.


> The original coal gasification process:
>
> 1sr stage: Pyrolysis -- product -- very rich coal gas
>
> 2nd stage -- producer gas --
>
> 3rd stage -- steam reforming -- syngas
>
> Stage two and stage 3 were "flipped" continuously till completion.
>
> There is no reasons that same "complete" process can't be achieved with 
> any
> woody biomass.


Well, I have no experience of what you suggest as possible, but it would be 
quite technically challenging to set up a system, particularly on a scale 
that most of us could afford to develop, and then, who for? Before you 
bombard us with how to do it with impossibly complicated mathematical 
argument, it still has to be built using considerable knowledge outside of 
which you can provide.


> If we were capable of "new-ideas" -- that is!!


New ideas  are not your soul prerogative, and it is only ideas where you use 
materials immediately to hand that can materialize something to test. My 
time has no value thinking of "new ideas" in the sense of the word, but 
solving problems created by others, allowing my narrow field of knowledge to 
be utilized.( certainly by people smarter than I)


> Actually -- there are dual cycle gasifiers in operation --
> pyrolysis/gasification of pyrolized materials after -- two separate
> processes being done in one "streaming" reaction.
 > In Europe -- of course.


Of course it is aways done some where else, because thinkers are not limited 
to the English speaking countries, and why duplicate some thing that has 
been done. This is not thinking, it's copying.


> I could replicate such by using two of the four Chinese gasifiers I have
> and working in batch mode -- or three -- or four. As charcoal gasification
> is probably a lot slower than pyrolysis -- 


This is the result of so much time lost to OT subjects. Who told you that 
charcoal gasification was slower than pyrolysis? In what context are you 
making this assumption?


> The end result is a cleaner gas -- 


Probably might, but to what end, just to prove  point it can be done?

>
> The off-gas from the pyrolysis -- very "dirty" is cleaned by passing
> through the second stage -- the gasification of char.
> Arnt used to describe doing something along these lines- - years back --
> all in one gasifier.


If you had a better understanding of how all these phenomena develop in a 
gasifier from your own experience, then I'm sure you will be far better 
equipped to develop your "original ideas".


> If one wanted to further develop new ideas -- there are so many "options"


Yes, that is the addictive attraction, "options", their continuous 
consideration means you never get past the reviewing process.


> Maybe building a WWII model of gasifier then tweaking it is not the right
> start up point??


Not unless you know nothing about gasification to understand what you are 
trying to achieve. The phenomena is valid right across the gasification 
spectrum.


> The one single point I do believe is very valid -- 
> The best way for small systems to convert any of these product gases to
> power is by using an IC engine!!


I can only agree, so get off the key board and get your gasifiers going(;-)

Doug Williams.