Dear Rex and All; Merry Xmas and happy synthesizing.
Rex must be a chemical engineer because he has outlined the problem nicely below. A partial solution is reaction of only the 80% cellulose in the wood to make a synthesis gas: C6H10O5 + 1/2 O2 ===> 6 CO + 5 H2 And leaving the 20% lignin behind as charcoal (Biochar) for soil enrichment and atmospheric CO2 reduction. Reaction of part of the CO with water reduces the unbalance to an excellent synthesis gas: 6 CO + 5 H2 + 3 H2O ===> 3 CO + 8 H2. || ==> 3CH2 (oil) + 3 H2 Leaving enough excess H2 to drive the reaction forward. Toplit Updraft gasification consumes the cellulose , leaving the lignin as Biochar. <><><> I am an expert in molecular sieves, and have made a quantity of a Fischer Tropsch catalyst with one isolated Fe atom per unit cell. Should make a low MW diesel. <><><> If anyone has the means, and would like to pursue this, contact me privately with an offer. Tom Reed Dr. Thomas B Reed 280 Hardwick Rd Barre, Ma 01005 508-353-7841 > On Dec 16, 2013, at 2:56 AM, "Rex Zietsman" <[email protected]> wrote: > > Hi All, > > We are looking at a system that will hydrotreat bio oils from pyrolysis, > catalytic cracking and vegetable oil. For this we need in the region of 30kg > hydrogen/ton oil. At small scale ie 1 ton oil/hour, this works out at, you > guessed it, 30kg of hydrogen/hour. As this is a small amount in the overall > scheme of things, we are looking at gasifying wood chips and to recover the > hydrogen using pressure swing absorption. What I would like to know is > whether we can increase the H2 concentration in syngas by tweaking the > gasifier. Clearly we can look at the water gas shift reaction but, as the > syngas has to be cooled, washed, pressurised and reheated, it is quite an > additional investment for the scale we are looking at. If we could simply up > the H2 content, we would go straight from washing to PSA. Residual gas would > be piped to a diesel generator where CO and the like will be combusted prior > to exhaust to atmosphere. > > For easy mental arithmetic, let us assume a 33% H2 concentration in dry > syngas. 30kg/hour of H2 is 15kmol/hour or 15/0.33 = 45kmol/hour of syngas. A > kmol of gas has a volume of 22.4 Nm3. So, to get 30kg/hour requires 22.4 x > 45 = 1000 Nm3 syngas/hour (mental arithmetic here, go with the flow). > Assuming an 80% PSA recovery this means that we need 1250Nm3/hour of syngas. > Not a bad sized downdraft gasifier! Assuming 6MJ/Nm3, this is around a 2MW > thermal unit. If we can get the H2 concentration up to say 40%, then the > syngas requirement would be 37.5kmol/hour or 37.5/45 x 1250 = roughly 80% of > 1250 or roughly 1000 Nm3 syngas/hour. This reduces the size of gasifier to > 1.6MW thermal and more sensible in size. > > > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. > http://www.avast.com > > > _______________________________________________ > 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/ _______________________________________________ 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/
