[Gasification] Lignin, Tar, and Mesquite

[Ray Menke]

On July 9th, Dr. Reed wrote: "Pyrolytic  gasification
Wood + Heat ==> Charcoal + vinegar gas ( acetic acid etc.)
is a piece of cake compared to total gasification in which lignin
contributes phenolics to make  tars."
Also, on April 24th on the Stoves List, he commented: "I read that the
lignin content of most wood is 15-25%, but that Mesquite is 64%."

This morning as I was nearing the end of a cooking session using a
pair of TLUD stoves, I added some 1" cubes of mesquite hardwood so I
could extend the burn time of both of the stoves.  I noticed a short
burst of tarry smoke when I dropped three or four of these little
chunks into each stove (near the end of the run).  (Usually, I remove
the pot or pan and toss several chunks of junk softwood into the
stove..This time I wanted a little more heat, so I threw in the
Mesquite chunks.)
>From this observation, should I conclude that dry Mesquite would not
be a good fuel to use in a Micro Gasifier where engine grade gas was
desired?  Would it be a more difficult task to break down the Tar in
the hearth?  If one could somehow find the magic in the proper hearth
design and the exact air flow rate, could the tar be totally consumed.
 I guess if it wasn't totally consumed (cracked), one would end up
with a nasty mess in the cyclones, coolers, and filters.  If one used
mesquite charcoal in the micro gasifier, would the problem go away?
By "micro gasification", I'm thinking of hearth restrictions in the
range of 2.5 to 3.5 inches in diameter.
Is the extra lignin a good thing to have, or should I start collecting
cedar and scrap construction lumber for future use?


-- 
Ray  Menke