What percentage of char production would be expected if the wood was cooked in an oxygen free reactor? Some of the liberated gasses could possibly be used to provide the heat externally, is it possible to "COKE" wood? GFWHELL In a message dated 2/10/2014 11:47:18 A.M. Eastern Standard Time, [email protected] writes:
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:[email protected]] On Behalf Of Evan Marks Sent: Monday, February 10, 2014 5:09 AM To: [email protected] 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 [email protected] 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/ _______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] 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/
_______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
