[Gasification] r.e. What is the difference between a gasifier and a charcoal kiln?

[Mark & Elena Gallmeier]

>>What is the difference between a gasifier and a charcoal kiln?<<

>From the view point of the end result, a gasifier produces a fuel gas (or synthesis gas if oxyidized with oxygen) while a charcoal retort produces a solid fuel in an anaerobic atmosphere.  From the standpoint of operation, a gasifier's pyrolytic processes are conducted entirely inside the gasifier, to include generation of heat.  The charcoal retort uses external process heat.  This heat initially comes from fuel entirely separate from the char feedstock, and is usually supplemented by reburning the off-gasses from the char feedstock generated by internal pyrolysis to drive the internal pyrolytic reaction.

Contrary to the EPA's write-up, charcoal retorts come in all sizes.  

An interesting question that may refuel the Great Gasification Definition Discussion.  I think about it time to time while working on my salvaged electric water heater ==> small charcoal retort conversion, which is 60% complete.

Mark

p.s.  Salvaged electric water heaters are a superb free source (in North America) of 13 gauge steel tanks in 20-60 gallon sizes.  Basically 12" to 22" diameters and varying heights.  And invariably unrusted.  Ignore the condition of the exterior sheet steel casings, which often are rusted.  The actual tanks all have heavy 3/4" sacrificial anodes inside to prevent rust.  You can find these 'junkers' outside service & repair oriented plumbing contractors' shops next to the dumpster.  Unlike steel oil drums the heavier tank metal tolerates welding processes very well.   Initially factory pressure tested to 300 psi and they come with an abundance of female 3/4" NPT fittings already installed in the top and down the side right to the bottom.   Usually seven of them.

FYI for our homeowner members, I have yet to encounter a salvaged electric water heater whose actual interior tank was leaking.  I've worked with 5 so far pulled from next to dumpsters and leak tested them as the first step after recovery to the workshop.  'Failure' was invariably the result of failed copper fittings (frequently the solder joints) or of the thermocouples, which also could have been replaced, or the plastic bottom drain valve.   All of these parts are cheaply availabe at the local hardware.  A point to keep in mind before spending several hundred dollars having a water heater replaced.   It might be 'cheaper' to pay a contractor with an $80/hour rate to simply replace the unit, but I doubt it.  


Message: 1
Date: Sun, 28 May 2006 16:20:01 EDT
From: CAVM at aol.com
Subject: [Gasification] What is the difference between a gasifier and
a charcoal kiln?
To: GASIFICATION at LISTSERV.REPP.ORG
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www.epa.gov/ttn/chief/ap42/ch10/final/c10s07.pdf