[Stoves] Design for a stove/heater for making biochar

[ajheggie at gmail.com]

On Tue, 21 Feb 2023 at 13:32, Ashok Mathur <ashokchand2000 at yahoo.com> wrote:
>
> Dear All,
> This note is a slight deviation from the discussion on bio-char.

Hi Ashok

We normally discuss biomass burning cook stoves here, some of which
produce char too, the busines of making and application of biochar is
best discussed on the biochar list

https://biochar.groups.io/g/main


> Usually bio-char is made in drums that exclude air and are heated by electricity.

Drums that exclude air and are heated are retorts, outside of research
and laboratories I doubt any heating is done by electricity as that
would be too expensive, It is usual to preheat them with a wood
burning fire and then as  pyrolysis takes place the offgas is burned
to heat the retort more. Cookstoves that produce char by the top lit
updraught configuration are technically kilns as the combustion and
char making take place in the same chamber.

There are several designs of rice husk gasifiers that burn very
cleanly, often discussed here in the past, I do not remember any
mention of coating them with sand or iron ore.

I confess I bake flat breads in an electric oven though.


Andrew