[Gasification] Design Parameters based on Superficial Velocity

[Mark Ludlow]

The environment that it takes place in will be a combination of gases being
admitted to the chamber from external sources (on-purpose or unavoidably) as
well as from gases that are generated by pyrolysis or distillation of the
wood. In no cases will there by a vacuum during operation, although if a
condensing apparatus is part of the system it is possible to operate at a
reduced pressure.

Mark

> -----Original Message-----
> From: gasification-bounces at listserv.repp.org [mailto:gasification-
> bounces at listserv.repp.org] On Behalf Of Steve Carroll
> Sent: Tuesday, August 22, 2006 7:49 AM
> To: gasification at listserv.repp.org
> Subject: Re: [Gasification] Design Parameters based on Superficial
> Velocity
> 
> 
> 
>  Thanks for those replies.  So I guess that at least
> with a fuel like wood that it would pyrolysize in any
> number of environments, each giving off a different
> mixture of products.  So I could pyrolysize wood in a
> vacuum, in air, in CO2, or whatever else I wanted to.
> Interesting information, probably even more
> interesting to someone with a chemistry background.
> There is a company in my town that holds a patent for
> a gasifier whose end product is acetylene.  I don't
> remember if they added the additional material in the
> pyrolysis stage or in the gasification stage.
> 
> > There are indications that once started, pyrolysis
> > is autothermic for
> > *bone dry wood*.  I have set up very well insulated
> > systems to test
> > this, but haven't accomplished it yet.  However, the
> > energy required for
> > pyrolytic gasification of Denver dry (8% moisture)
> > wood is probably < 5%
> > of the heat of combustion (21 MJ/kg; 8500 Btu/lb).
> >
> > But of course BDW doesn't occur in nature.  We are
> > planning to measure
> > the minimum air required for flaming pyrolysis as a
> > function of moisture
> > content, but don't hole your breath....
> 
> Autothermic pyrolysis?  I haven't found a good
> definition for that term yet but it sounds impossible.
>  Maybe someone would enlighten me.
> 
> My original question in context:
> 
> --snip--
>   Volume of primary air:  Kind of a side question here
> but; does the volume of air control how much fuel can
> be pyrolysized or can pyrolysis take place in a
> complete vacuum?  Same question for gasification.
> /--snip
> 
> The gist of the question was about how much control
> can I excersize over the entire process just by
> modulating the flow of primary air.  I would imagine
> that the range would be limited by your throat size
> due to the change in SV.  Has anyone designed anything
> with a modulating throat?
> 
> BTW Tom, how did you change the velocity in that TLUD
> sv test?
> 
> Holding My Breath,
> Steve
> 
> 
> 
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