j cornelissen

taking the fan out of the equation means you don't hve to worry about cold air being pumped in on a cloudless day!

G'day

seeing hot air rises, and provided you had the space, would it be possible to position one of these units underneath a window and run it without an electric fan?

cheers, Jan

here in Australia salination of the soil is a massive problem.

it is caused by deforestation of the land and subsequent reduced water usage. Fewer trees, less water uptake and hence rising ground water. The rising ground water levels bring up minerals (salt) to the surface making the pastures infertile.

the solution is lowering the ground water levels, this is done by pumping up water (not ideal) or planting salt-tolerant deep-rooted plants / trees like saltbush (excellent stockfeed for nice tasting lamb) and alfa alfa

ironically, we're dealing here with drought as well as rising water levels (i don't think we could have screwed things up more if we tried)

Jan

Hi Erica,

yeah you're right the way things are done at the moment is completely insane. Bit by bit people realise the soil has been depleted further and further with the conventional way of fertilizing.

There are people now that use animal manure on a large scale to fertilize their land (duh!). They find they can increase the P levels, much higher and for longer than with the conventional way of fertilizing. On top of that they'll accomplish improved water retention.

Once you get the process going (you need an initial amount of E input) the energy release of pyrolysis is enough for further pyrolysis as well as produce electricity so that's all great. I agree with you that the danger lies in people starting to produce charcoal without using the woodgas released in the process thus increasing the amount of greenhouse gas.

My lessons will concentrate on a 3rd wrld setting for the stoves and all the advantages for the people using them (health, time gained, safety for those collecting wood, less deforestation etc etc)

Will let you know how things go.

Cheers, Jan

Hi all, thanks for the useful replies, I think I've got my head around the science side of things.

Coming back to the biochar side of things, a couple of things;

Biochar is a proven improvement to soil structure as was observed in the Amazon basin. It works by absorbing both water and nutrients, giving much higher crop yields. It offers a structure for microbes to prosper.

Production of biochar through pyrolysis yields both gases that can be burned as well as biochar that can be used to improve soil structure.

Here in Oz there's a plant that uses the energy released by burning wood gas to produce :
-electricity
-as well as cause more pyrolysis hence more gas, more energy
-the very useful by product is biochar.

It is by far the most simple, feasible to improve our current predicament. Granted, growing more 1000 year old forests is preferable, the drawback is it takes a 1000 yrs............

Here's a plan for the anila stove
http://www.bioenergylists.org/files/images/Biochar_Anila_s_Page_13.preview.jpg

that produces biochar, which is part of a secondary process in the double wall of the burner, quite ingenious.

Got some interesting sites on biochar if anyone is interested

http://terrapreta.bioenergylists.org/taxonomy/term/253
http://www.theoildrum.com/node/4522 this one is particularly good, watch the you tube clips

cheers, Jan

Hi I hope I'm putting my post on the right spot, if not pls let me know I'll start a new thread.

Like so many people on here, reading about the various types of stoves I am getting very exited and want to build one!

My reasons for building one are slightly different tho'. I am a science teacher here in Melbourne and a colleague and myself are developing a sustainability unit for the highschool we're working.

Building them won't be an issues seeing all the wonderful info around, I'd like to know a bit more about the science behind it.

I understand the "butt warmer" concept with the combustion chamber, that serves for a more complete combustion of the fuel, I'm not quite clear on the rocket-stove science though and have a number of questions.

Why does the elbow shape help in the more efficient use of the fuel?
Is it simply because you direct the heat towards the cooking area (if so why doesn't every gas cooker come with rings around the heating points!)

Or- does the length of the chimney-like vertical part of the stove accommodate a 2nd stage combustion?

It would be great if I could get some answers that could explain the positive sides of these stoves.


Btw we're looking at including the biochar story into the unit and the idea is to combine the rocket stoves with pyrolysis of wood and hence biochar production (in short the Anila stove, probably got that name wrong), and with a bit of luck demonstrate the positives of biochar as well (to give you the full picture).

Cheers, Jan

fascinating stuff

makes you wonder why any standard fire place isn't fitted with an extra combustion area

anyone used this for cold smoking ham and fish or is the exhaust too clean?

cheers, Jan