[Gasification] Cellulose Gas and Biochar option

[Evan Marks]

Tom M.

Rather, it would seem that perhaps a study is needed! -EM





Tom,



While it is easy to visualize the concept of lignin converting to char It
would be more correct to say that a portion of the lignin decomposes during
gasification and partial oxidation. Since lignin degrades starting at
200-300 C the gaseous and vaporous products of this degradation are surely
carried off in the gas that burns when exposed to the secondary air. You can
get less char from grasses that have a higher lignin content (22%, bagasse)
than wood (15% eucalyptus). The net char yield of charring either of these
in a TLUD can be (24%)  greater than the intrinsic lignin content. Also in a
TLUD air/gas flows are rarely uniform. Surely some of the char itself is
oxidized by the primary air, generating heat to help drive the gasification.
I suspect that while lignin may be the principal precursor of char, the char
is probably a blend of products of decomposition of lignin, hemicellulose
and cellulose. I would think that someone has done a study of the
decomposition of cellulose, hemicellulose and lignin in a TLUD. 



Tom Miles