Dear GF ----- Original Message ----- From: [email protected] To: [email protected] Sent: Thursday, November 28, 2013 8:32 PM Subject: Re: [Gasification] Fluidised Bed Reactor
Phil, Why not make the exhaust manifold, the structural part of the pyrolysis section of our gasifier. A heavily loaded gasoline engine driving an alternator will produce enough waste heat to carbonize the biomass. # That would certainly work, as a pyrolyzer. The effect would be like a "heated retort." It would indeed produce char, and pyrolysis gas. # However, teh pyrolysis gas would be very tarry, and would not be suitable for "Engine Grade Gas" without adequate cleaning. However, it would be very good as a "Heating Grade Gas." Note that even with the higher exhaust temperatures for heavily loaded diesels indicated by Phil, the temperature is marginally low for the CO2 + C --> 2CO reaction to happen completely. Best wishes, Kevin GF In a message dated 11/28/2013 6:32:44 P.M. Eastern Standard Time, [email protected] writes: Hi Kevin: A loaded diesel can easily run egt of 550-650C. Pyrometers are common on big diesels but it does depend on where the measurement is taken. Phil Marsh Marshbros. 250 569-7858 From: Gasification [mailto:[email protected]] On Behalf Of Kevin Sent: November-28-13 12:27 PM To: Discussion of biomass pyrolysis and gasification Subject: Re: [Gasification] Fluidised Bed Reactor Dear GF ----- Original Message ----- From: [email protected] To: [email protected] Sent: Thursday, November 28, 2013 11:51 AM Subject: Re: [Gasification] Fluidised Bed Reactor Kevin . What sort of reaction could be expected if we applied the high temperature exhaust from an IC engine into a "reactor" containing biomass and at the same time reheated the "reactor" using some of the volatile vapors so produced? # My understanding of exhaust twemperatures is that they run something as follows: (Anyone who knows better, please correct me:): Unloaded Loaded Diesel ~300F=150C ~ 752 F =400C Max Spark. Ig: ~500F=260C ~752 F =400C Max I conclude that even "hot engine exhaust would not be sufficient to operate the C + CO2 --> 2Co reaction that requires temperatures in excess of 700C to run. perhaps we could also ionize the vapors produced within the reactor to above 5000 deg. which should yield a relatively low tar stream of gas .some of which could fuel the IC engine. # 5000 F would certainly run the above reaction. However, "Tars" areof the general formula CxHyOn. Such temperatures would certainly "partially crack" the tars, but probably would not "crack" them fully, to give a tar free gas. I am guessing you would end up with some CO, and some other tars of a different composition. However, they would likely be "heavier tars" that might be removed more easily. # The other issue is the energy required to "ionize" stuff at 5,000 degrees. This does not compromise the laws of Thermodynamics. # Exactly! Although many have tried, I don't know of any who have succeeded. Best wishes, Kevin GF In a message dated 11/28/2013 9:55:19 A.M. Eastern Standard Time, [email protected] writes: Dear Dan Quoting [email protected]: > Doug and all, > Would some sort of a high temp molecular cracker be a good companion > to create a quality gas from a fluidised bed? Possibly some steam and / or > preheated air .involved? Seems if you wrapped the exhaust back through the > hottest part of the flame in a reactor tube this can be accomplished. > Sorry but I have been kinda outta the loop for a while. # Start by appreciating the two Fundamental Rules of Thermodynamics and Thermo Chemistry: Fundamental Rule #1: You can't get something for nothing Fundamental Rule #2: As a matter of fact, you can't even break even. For example, the reaction C + O2 --> CO2 (`1) is strongly exothermic, and gives off about 14,000 BTU per pound of carbon that is oxidized. If there was insufficient O2, and the C was only burned to CO, as follows: C + 1/2O2 --> CO (2) then only abut 4,000 BTU would be released per pound of carbon. If we wanted to reverse reaction #1, we would have to put back 14,000 BTU/Lb C OR, in the case of a gasifier, where the reaction CO2 + C --> 2 CO (3) is desired, we would have to "put back" energy as follows: 14,000 + 0 --> 2x4,000 + "X" 14,000 --> 8,000 + "X" and it is obvious that "X" is 6,000 BTU, in order to respect Fundamental Rule #1 "Molecular Crackers" and "Catalysts" do indeed work, but only when the fundamental need to add or remove energy from a reaction is respected. As long as the "fundamental need for an energy balance" is respected, then many things are possible. Best wishes, Kevin > > Dan Dimiduk _______________________________________________ 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/ _______________________________________________ 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/
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