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Doug, (and a thank-you to Art for his comments also)<br>
<br>
Your archive update
<a class="moz-txt-link-freetext" href="http://www.fluidynenz.250x.com/Feb2015/Shasta2update.html">http://www.fluidynenz.250x.com/Feb2015/Shasta2update.html</a> 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.
<blockquote type="cite"><a class="moz-txt-link-freetext" href="http://www.drtlud.com/wp-content/uploads/2012/08/BP53-Anderson-14.pdf">http://www.drtlud.com/wp-content/uploads/2012/08/BP53-Anderson-14.pdf</a></blockquote>
<br>
I agree that what Rolf is seeking is not a TLUD. <br>
<br>
You wrote:
<blockquote type="cite">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.</blockquote>
I have not experienced carbon dust or ash from carbon dust or ash
dust with the AVUD design.<br>
<br>
Again, thank you for your strong support for gasification of
biomass.<br>
<br>
Paul<br>
<pre class="moz-signature" cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a class="moz-txt-link-abbreviated" href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a class="moz-txt-link-abbreviated" href="http://www.drtlud.com">www.drtlud.com</a></pre>
<div class="moz-cite-prefix">On 1/5/2017 12:27 AM, Doug wrote:<br>
</div>
<blockquote
cite="mid:eefb4417-eb2f-5127-4718-a2c37017805f@gmail.com"
type="cite">
<meta content="text/html; charset=windows-1252"
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<p><font face="Liberation Sans">Hi Paul,Rolf and Colleagues,</font></p>
<p>This is to clarify Paul's questions. I hope the separations do
not confuse too much.<br>
</p>
<br>
<div class="moz-cite-prefix"> >Pyrolytic gas can be quite wet
so precise temperatures are risky to quote. </div>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite"> 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). <br>
<br>
If the MC of the raw fuel was lower (such as 5% MC), would that
help raise the temperature?<br>
</blockquote>
<br>
The short answer is yes, we don't need steam to displace gas
volume.<br>
<br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite"> <br>
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?<br>
</blockquote>
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.<br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite"> <br>
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?<br>
</blockquote>
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. <br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite">
<blockquote
cite="mid:90a737c8-10b1-1d29-bbde-9ec4fde79cfe@gmail.com"
type="cite">
<p>What I can tell you from experience, is that it always
burns hotter than clean producer gas, upwards of 1,050C, </p>
</blockquote>
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?<br>
</blockquote>
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, <br>
<br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite"> <br>
But your next words I do not understand.<br>
<blockquote
cite="mid:90a737c8-10b1-1d29-bbde-9ec4fde79cfe@gmail.com"
type="cite">
<p>13-1500C is a rough rule of thumb for gas exiting the
combustion chamber. </p>
</blockquote>
</blockquote>
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.<br>
<br>
<br>
>I am not understanding what that means. The combustion
chamber is the "burner" of the pyrolytic gases?<br>
<br>
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.<br>
<br>
>>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. <br>
<br>
>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.<br>
<br>
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.<br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite"> <br>
Are your comments somehow referring to the FULL gasification
processes in downdraft gasifiers (pyrolysis AND
char-gasification are both occuring)?<br>
</blockquote>
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.<br>
<blockquote
cite="mid:ade70a21-d7a9-1513-3185-c427be457329@ilstu.edu"
type="cite">
<blockquote
cite="mid:90a737c8-10b1-1d29-bbde-9ec4fde79cfe@gmail.com"
type="cite">
<p> </p>
<p>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.</p>
</blockquote>
The above sentences seem to indicate that your explanation is
about FULL gasification and not about only the pyrolysis process
with resultant charcoal creation.<br>
</blockquote>
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. <br>
<br>
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.<br>
<br>
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)
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.fluidynenz.250x.com/">http://www.fluidynenz.250x.com/
</a><br>
<br>
Doug Williams.<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
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