faster fermentation through pyrolysis?

[Oak]

I read in some article that lignin in hardwood starts to degrade when the temperature reaches 240-260 degrees celcius. So if I were to heat sawdust to that temperature and ferment it using wheat bran and yeast,  wouldn't the sawdust, in theory, ferment faster due to the fact that bacteria don't have to spend their time breaking down lignin? Or is this not how it works? 

 

[PowerHobo]

I absolutely will not pretend to have solid answers here, but I did want to clarify that you're asking about heating the sawdust to that point for a while to break down lignin, then letting it cool back to "regular" temperatures and fermenting as normal, correct? Asking because I can say quite confidently that temps that high would murder the yeast before they can do their job. Yeast dies somewhere around 65C if I remember correctly. Furthermore, I would have severe concerns about the safety of heating even wet sawdust to 240F using any commonly available method for any considerable length of time.

 

[Goliathus]

...I would have severe concerns about the safety of heating even wet sawdust to 240F using any commonly available method for any considerable length of time.

Seconded!

My advice - stick to time-tested fermentation methods that are known to work well and safely.  Incidentally, wood can start to char at as little as 180 C.  I'm sure that wetness vs. dryness is a factor, but even if the material is wet when the heating process starts, it might not uniformly remain wet enough to prevent the possibility of ignition.  And, it's not just the potential for fire that's a threat - carbon monoxide can be produced too, if combustion starts.

 

[The Mantis Menagerie]

If you want to try this idea (Note: I don't know much about the nature and importance of lignin in beetle substrate as I am more familiar with the carnivorous insects such as Alaus oculatus), then you could try heating the wood in an autoclave or pressure cooker (maybe the added pressure might help denature the lignin?). Otherwise, I agree with the other users who have posted, heating fine wood chips to above 200-degrees Celsius is probably a bad idea.