[Stoves] Distillation and oxidation Re: Understanding TLUDs, MPF and more. (was Re: Bangladesh TLUD )

Andrew Heggie aj.heggie at gmail.com
Sat Jan 6 17:37:40 CST 2018


On 6 January 2018 at 21:39, Crispin Pemberton-Pigott
<crispinpigott at outlook.com> wrote:

>
> The evidence from the distillation of biomass to produce liquids and ‎gases shows that there is a conversion of biomass to CO2. Paul asks if the C is completely separated from the OH. It probably does now and then but it is not material. If it happens the heat is lost then regained, lost again and regained as the chemistry rapidly changes. What we do know is that in the end, there is only a net heat released from the biomass at 360C, and that the rest of the time the chemical changes leading to the gaseous products are energy-neutral. This of course is in the absence of air.

Crispin as you are the only one to use the term "distillation" in this
way I wonder if your gasifier expert is a native English speaker?

Too my mind distillation applies to the creation of a vapour and its
subsequent condensation, either in a simple condenser or a
fractionating column, to a purified liquid. In TLUDs we produce a
pyrolysis offgas that is a mixture of gases and vapours with maybe a n
aerosol of solid particles. This is then subsequently burned in a
secondary flame so no condensate is recovered.

We have known of the exothermic part of pyrolysis for years, Tom Reed
mentioned it 20 years ago, but does the heat at 360C amount to less or
more than that necessary to raise the dry wood from ambient to 360C?

Andrew




More information about the Stoves mailing list