Many thanks to Doug, Paul and others. Sorry, I had a busy day away from home and could not check my mails.
The Shasta 2 carbonizer is a very interesting design. How could it be optimized to make high temperature "flare" gas? Recover heat from the char cooling to preheat the combustion air? Rolf On Thu, 5 Jan 2017 16:26:09 -0600 Paul Anderson <[email protected]> wrote: > Doug, (and a thank-you to Art for his comments also) > > Your archive update > http://www.fluidynenz.250x.com/Feb2015/Shasta2update.html was very > informative. Although larger and with operational differences, there > are strong similarities with the Chip Energy Biomass Furnace that Paul > Wever and I designed and made some years ago. Info is at > chipenergy.com That is not a TLUD, but is a true up-draft gasifier with > a few innovations that I have written about in 2007 as AVUD (Another > Variation Up-Draft) gasifier. > > http://www.drtlud.com/wp-content/uploads/2012/08/BP53-Anderson-14.pdf > > I agree that what Rolf is seeking is not a TLUD. > > You wrote: > > May be the ash from the carbon dust will settle in the tunnel > > depending on combustion gas velocity. Usually, a correctly sized flue > > stack is required to assist with removing the exhaust gas, and this is > > where ash dust can become an emission. > I have not experienced carbon dust or ash from carbon dust or ash dust > with the AVUD design. > > Again, thank you for your strong support for gasification of biomass. > > Paul > > Doc / Dr TLUD / Prof. Paul S. Anderson, PhD > Email: [email protected] > Skype: paultlud Phone: +1-309-452-7072 > Website: www.drtlud.com > > On 1/5/2017 12:27 AM, Doug wrote: > > > > Hi Paul,Rolf and Colleagues, > > > > This is to clarify Paul's questions. I hope the separations do not > > confuse too much. > > > > > > >Pyrolytic gas can be quite wet so precise temperatures are risky to > > quote. > >> Yes. There is no scrubbing or drying or other preparation of the > >> pyrolytic gas. In the TLUD world, the gases are usually created in > >> the 500 C to 650 C range. And the raw biomass fuel might enter with > >> as much as 15% to 20 % Moisture Content (MC). > >> > >> If the MC of the raw fuel was lower (such as 5% MC), would that help > >> raise the temperature? > > > > The short answer is yes, we don't need steam to displace gas volume. > > > >> > >> Hypothetical question: Part A. if the pyrolytic gases were cooled > >> to below 100 C, water could be removed by condensation, and we would > >> have lots of wood vinegar. However, there would also be massive > >> amounts of tars and "gunk" being deposited also. However, the > >> final, non-condensed gases just might have the desired temperature > >> when combusted. Those gases would be H2, CO, > >> methane-and-related-gases, and what else? > > Cooling the gas is a waste of the heat that it contains. Any condensed > > tars, hydrocarbons, or vinegars may have applications, but also add to > > the technical difficulties for their collection. Their removal, other > > than moisture best removed by drying the wood, reduces the calorific > > energy of the pyrolysis gas. Difficult to calculate, but also adding > > to the gas heating value will be carbon particles. Normally we would > > seek to minimize these by using a cyclone, but ceramics need reducing > > atmospheres, or read that as carbon rich heated atmospheres, so carbon > > dust is great. > >> > >> Part B. Alternatively, after the removal of the wood vinegar, > >> perhaps the remaining gases plus the reheated tars, etc. could be > >> reheated to become a dry, quality gas for higher burning > >> temperatures. All of this would be with losses of thermal energy > >> during condensation and then the need to add thermal energy. Could > >> this have benefits that could justify the expense? > > I think the previous answer covered this, but I see no benefit at all > > to this suggestion. At a later date after there is a system working, > > you will then have opportunity to extract condensates. Our experience > > tells us that as toxic black liquor, the less you have the healthier > > the working site. No exaggerating, it's a health and safety hazard. > >>> > >>> What I can tell you from experience, is that it always burns hotter > >>> than clean producer gas, upwards of 1,050C, > >>> > >> If that is the maximum, will this be sufficient for Rolf and his > >> friend to use? There is no way to turn 1000 C into 1300 C, correct? > > Not well explained, sorry. Clean tar free gas will not burn over > > 1,050C, but if the system design produces pyrolysis gas which has all > > it's hydrocarbons, then the temperatures will be upwards and over > > 1,050C, a basic tar test for cleaner specification gas, > > > >> > >> But your next words I do not understand. > >>> > >>> 13-1500C is a rough rule of thumb for gas exiting the combustion > >>> chamber. > >>> > > If you combust pyolysis gas full of hydrocarbons, then the flame > > temperature will be 1,300-1,500C. One of the most difficult areas of > > combustion is that thermo-couples start going crazy over 1,300C. > > Expensive ceramic ones damage too easily, so once the TC melts, you > > know the higher temperatures are present, possible over 1,500C. > > > > > > >I am not understanding what that means. The combustion chamber is > > the "burner" of the pyrolytic gases? > > > > The short answer is yes if we were just creating heat. Ceramics like > > Rolf is seeking to fire, are done in a tunnel kiln, and the tunnel > > becomes the combustion chamber. The geometry is important to create > > the combustion phenomena, but to design this we first need a tunnel > > kiln to use. > > > > >>It has a very high radiation factor useful for refractory > > application, but the price for this is that you will get a high ash > > content in the kiln and flue dust emissions. > > > > >Something in the above sentence is not clear to me. The "kiln" is > > part of the gasifier or is it where the materials are being heated? > > And the pyrolytic gases of TLUDs do not >have ash in them. And I am > > not understanding the source of any flue dust emissions. > > > > The gasifier is close coupled to the kiln, and the burner is mounted > > in this case, on the end of the tunnel kiln which forms it's own > > combustion chamber containing the ceramics. The spent gas has to exit > > the tunnel at some point, above the condensation temperature. May be > > the ash from the carbon dust will settle in the tunnel depending on > > combustion gas velocity. Usually, a correctly sized flue stack is > > required to assist with removing the exhaust gas, and this is where > > ash dust can become an emission. It would be good to put aside TLUD > > understanding, as they work on a totally different principle not > > relevant to this project need. > >> > >> Are your comments somehow referring to the FULL gasification > >> processes in downdraft gasifiers (pyrolysis AND char-gasification are > >> both occuring)? > > No, Downdraft gasifiers more often than not make pyrolysis gas and > > need char extraction to work. Full gasification as you say, need > > minimum bed disturbance and between 1-4% of the fuel drops out as > > char. Rolf only has a downdraft engine gasifier for his first trials, > > and we should get plenty of pyrolysis gas out of that, at least for > > the first tests to fire the ceramics. Maybe we will have to extract > > char as well, but all that is still a long way off at this point. > >>> > >>> The actual combustion is complex, but achievable in a non regulated > >>> situation, emissions being the issue, both dust and toxic gas > >>> CO,CH4, and Dioxins. Combustion of these gases have been our focus > >>> for some 6-7 years, and current work at CalForest in California, is > >>> to use this gas to dry the incoming fuel to the charmaker. > >>> > >> The above sentences seem to indicate that your explanation is about > >> FULL gasification and not about only the pyrolysis process with > >> resultant charcoal creation. > > We take raw producer gas from the Shasta gasifier, meaning hot > > cycloned hydrocarbon free downdraft gas for the boiler green house > > application. This has high carbon dust content which burns to ash. > > This is a problem for the boiler, but just needs more cleaning cycles > > than anticipated. > > > > The Charmaker is an updraft system and burns to waste the very dirty > > pyrolysis gas. The gas flare vertically from high stacks making them > > safer, as we have no space to work with them on the ground. The > > radiant heat cooks you from about 3-4ft, so the chances are, unless > > you have stood by an oil rig flare, many researchers just haven't > > acquired this type of experience from pyrolysis gas flares. > > > > You might like to look again at the Fluidyne Archive last update > > showing the charmaker and gas flares in action. The bigger flares at > > higher output are not shown mainly due to us too busy keeping up with > > the input fuel flow. Earlier updates show the Cyclomix burners and > > combustion chamber hooked to a heat exchanger, so there is plenty of > > info to brush up on as we developed these larger gas making system > > components. When operational, we collect data from those points > > important to both the gasifier and process, including continuous gas > > analysis, which cannot be used for pyrolysis gas. (to dirty) > > http://www.fluidynenz.250x.com/ > > > > Doug Williams. > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > 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/ > -- Energies Naturals C.B. <[email protected]> _______________________________________________ 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/
