uwe <uweb@MEGALINK.NET.MX> wrote:

>....I'm a technician in solar and alternative energies...
>Regarding the digestor, etc., in the moment we don't even have
>begun the construction of the orphanage; we are still in the planning
>stage.

Though it is often useful to have an overview of the final dream for the
orphanage, the practice of IBS comes only after you start the orphanage and
start to generate the a substantial amount of wastes and/or water needed
the implementation of a sub-system. Of course wastes can be handled in
different ways and IBS is just one of them. What is unique in IBS is that
it converts wastes which may even be a burden into useful products.

There is also a great potential in the use of solar energy which you have
in abundance in Mexico. An interesting technology to harvest solar energy
for cooking is to transport the energy in oil to the kitchen for recipes
that needs slow cooking, just as what solar cookers offer.

>Cowdung for the digestor will be imported from the corrals, which don't
>know what to do with it. And our cooking fuel will be the biogas we
>produce.

Transporting cowdung daily to feed a digester has been done before. The
project in Salatiga, Indonesia will also depend on this approach and can be
successful if you have cooperation of the community.

If you have a 50-100 m3 operating volume digester (that will also takes
care of the sewage), you will need to 2-3 m3 of slurry as influent. A mix
of 1:1 (manure:water) is often used. This means that you need to bring in
1-1.5 m3 of dung everyday.

>Basically the idea is, to make it right from the beginning, as any
>posterior correction would cost extra money. And as donations will also be
>scarce all the time, an integrated biosystem would combine nicely all the
>needs and byproducts in one economically sustainable production cycle.

if you are referring to operating an integrated bio-system, please note
that an IBS is not something that one can just "switch on" with guaranteed
operation !! It is a chain of actions and any disorder at any point can
eventually cause the disruption of the whole system. Since I understand
that the orphanage is still to be built, I would (a personal opinion only)
focus efforts on the funding for the construction and daily requirements of
the children first. The integrated bio-system can be designed after you
have a functional orphanage.

Good luck
Jacky Foo