[Gasification] Cellulose Gas and Biochar option

[Tom Miles]

Evan,

Studies that we have seen show that about 50% of the char is derived from
lignin and about 25% each from cellulose and hemicellulose. I'd have to dig
into the studies to qualify the conditions of gasification and the species
involved but it is clear that each of the fractions is carbonized with the
dominant char fraction being from the lignin. 

Tom 

-----Original Message-----
From: Gasification [mailto:gasification-bounces at lists.bioenergylists.org] On
Behalf Of Evan Marks
Sent: Monday, February 10, 2014 5:09 AM
To: gasification at lists.bioenergylists.org
Subject: Re: [Gasification] Cellulose Gas and Biochar option

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  

_______________________________________________
Gasification mailing list

to Send a Message to the list, use the email address
Gasification at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenerg
ylists.org

for more Gasifiers,  News and Information see our web site:
http://gasifiers.bioenergylists.org/