pyrolysis in a common microwave oven?

[the guy]

would it be possible to induce pyrolysis of plant material in my microwave oven?

[Essay]

would it be possible to induce pyrolysis of plant material in my microwave oven?

 

No.... Well, I'd be very surprised if it could be made to work; and even if you could, that is a very energy intensive way to run pyrolysis. Microwaving might be useful in an industrial scale pyrolysis process, as one part of a larger scheme to maximize oil production... but I don't think it'll work in a kitchen setting.

 

First, the name pyrolysis (breaking by fire) suggests that fire is involved, and that wouldn't work well in a microwave; plus the "lysis" part suggests breaking chemical bonds, and conventional microwaves work by making water molecules vibrate (boil) and so aren't strong enough to break (biomass) bonds requiring temperatures (like fire) above boiling water.

 

Mainly though, it is the exclusion (or reduction) of oxygen during pyrolysis that would be hard to maintain in a microwave on your kitchen counter. Venting the steam would be problematic also, but on an industrial scale both of those difficulties might prove to be useful in some way. But using strictly microwaves would probably only yield some tarry resin, if any transformation of the biomass could be achieved.

 

For pyrolysis around the house (outside, or in a well-vented indoor area), I use the woodgascampstove, which may be made by a different company now but can still be searched as a word (woodgascampstove). If you are interested in pyrolysis of biomass, it's very handy and simple. All of the structure within the biomass is retained; it is like petrified life.

 

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[J.C.MacSwell]

would it be possible to induce pyrolysis of plant material in my microwave oven?

 

I've never done it intentionally, but I'm pretty sure I've done it accidentally, overcooking the core of something I've reheated by leaving it go too long.

Edited June 22, 2011 by J.C.MacSwell

[Green Mark]

Hello,

 

Pyrolysis of biomass is perfectly feasible in a microwave system and (me and my colleagues believe) more energy efficient. Similarly, the use of a domestic oven is completely possible, in fact one of the machines I use is based, albeit with improved temperature and power control, from a domestic 1000 W domestic system.

 

Microwaves are energy intensive per unit time but as they can enable extremely high heating rates and therefore pyrolysis can be carried out at lower temperatures, with more control and using less energy.

 

I apologies for the blatant promotion of my work but... please see http://www.york.ac.u.../microwave.html for a basic discussion and information about work in this area.

 

There are other research groups in the USA and Spain amongst others utilising microwaves to induce pyrolysis.

 

Happy to discuss further with anyone interested!

 

University of York Pyne Guide.pdf