[Gasification] mycoremediation of tarry water

[doug.williams]

Hi Arnt,

You ask:

> ..quick question: H2 needs how much longer dwell time than CO?

For many years I was locked into H2  formation as only a temperature dependant disassociation, but this has been shown to be incorrect by the continuous gas analysis we have been able to use for the development programme in California. As we increased the output over a range of bed depths, H2 dropped, while CO tended to increase. You could always find a sweet spot for a chosen depth, but H2 formation lagged if you pulled harder.

If you increase the bed depths to increase the contact/dwell time, even by say 25mm, the H2 will increase, but then so does bed resistances. Time taken has to be nano seconds, but as you have discovered, a good sneeze can help maintain the bed porosity(:-)

There are many ways to skin this cat, but the basics remain the same based on the experience so far. It would be great if gas was only made at a fixed output, then variations of every type could be controlled.

Doug Williams,
Fluidyne------





> 
>> Question. Have you done continuous gas analysis from start-up to shut
>> down?
>> 
>> Your question mark in the equation suggests a combustible gas
>> (~CH20), which would have to survive the combustion /oxidation phase,
>> or does this vaporization take place as a portion of the char is
>> consumed first in oxidation,then reduction? Looking at these
>> gasifying stove rings burning as a blue gas, one might conclude that
>> there is little if any condensable tars present. If CH20 survives to
>> be measured as a gas, it's formation may be reflected in the H2
>> variation if present, depending on exactly where the H2 forms. Having
>> said that, I have no experience to draw from, to know if there is
>> enough thermal inertia after reduction to allow "other" reactions to
>> take place.
>> 
>> As soon as we get some warm weather, I'll try to measure the tar
>> content from each, using my 2 kW generator and a 5 gal tar filter
>> made from the charcoal. Comments, suggestions?
>> 
>> As you expect to capture tars in charcoal, then I would want to have
>> good control over the gas cooling/filter temperatures, as the dew
>> points of the fuel moisture content are linked to carrying lighter
>> pyrolysis gas/oils through filter media. I'd want to know, especially
>> the downdraft gasifier, if it had a proven ability to make gas
>> without or known condensing hydrocarbons, using the fuels of the test.
>> 
>> You also have the engine to feed you lots of info as to gas
>> condition, and I would use that as a pre-test before you add the
>> charcoal filter. A quick look under the throttle butterfly could save
>> you a lot of useless testing if you see the sticky stuff in there! 
>> 
>> I'm sure you know all these answers already Tom, but will watch for
>> your postings of the results.
>> 
>> Regards,
>> Doug Williams,
>> Fluidyne----
>> 
>> 
> 
> 
> -- 
> ..med vennlig hilsen = with Kind Regards from Arnt Karlsen
> ...with a number of polar bear hunters in his ancestry...
>  Scenarios always come in sets of three: 
>  best case, worst case, and just in case.
>
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