[Stoves] Pyrolytic gasifiers

[Paul S. Anderson]

Quoting John Davies <jmdavies at telkomsa.net>:

> Paul,
>
> All oxygen present will react with carbon above about  400c to form  CO2.-
> exothermic reaction.- heat evolved  ~2X
>
> When CO2 without oxygen comes in contact with carbon at
> about 800c it will react and form CO -
> endothermic reaction.- Heat absorbed ~X
>
> If any oxygen comes into contact with the CO at high temperature
> it will react to form CO2 - exothermic reaction -Heat evolved ~X

Thank you, John, excellent comment that makes sense to me with my limited
knowledge of the subject.

It means:  In the limited-air environment of the updraft in the closed fuel
container, the O2 will drive the heat process but can be controlled 
because the
endothermic reaction will help prevent the process from getting out of 
hand. So, while some CARBON-gasification does take place, the 
appropriate heat higher
in the fuel container is driving the PYROLYTIC-gasification in the manner of a
retort where high temperatures (but without flame in that actual area of the
biomass) will drive off the volitiles, which is exactly what I desire in a
pyrolytic gasifier.

I think we have a winner with the bottom-lit updraft pyrolytic gasifier 
(with no
intention of being a traditional updraft gasifier).

When the inside temperature (as a retort) is above 400 C (such as about 
600 C),
that is plenty hot to have the retort-style of pyrolysis.

RELATED question:  Is it true that charcoal via retort is the same as charcoal
via the pyrolytic front having passed through the
biomass-that-becomes-charcoal?  I would think so.  AD Karve's making of
charcoal from cane trash is like the retort method and nobody ever said that
that form of charcoal was better or worse than charcoal where the flame is
present.

Today at the China workshop Dr. Makunde from India gave a full day of great
lectures about gasification issues.  Very clearly stated and helps me
understand what John wrote.  All on Power Point and to be provided on 
CD to the
participants.  I will suggest that it be available via link at    
bioenergylists.org

Paul
-- 
Paul S. Anderson, Ph.D., Geography professor - Emeritus
Telephone:  USA-309-452-7072 (residence and office)
Internet site:  www.ilstu.edu/~psanders
For my gasifier stoves info, go to:
http://bioenergylists.org/contributors#Paul_Anderson



>
> _______________________________________________
> Stoves mailing list
> Stoves at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
>



----------------------------------------------------------------
This message was sent using Illinois State University Webmail.