[Stoves] Energy loss in making high grade fuels

[Anand Karve]

Dear Stovers,
Ron Larson raised the point of energy lost while charring agricultural
waste in our portable charring kilns. I have since then been thinking about
loss of energy in making other types of fuels too. Take for instance
ethanol. I was told that the raw product of fermentation has less than 10%
ethanol, which is then repeatedly distilled to bring it to 95 (rectified
spirit). This is further treated to give 100% ethanol. There is also a lot
of talk about biomass pellets. Compressing light biomass into pellets or
briquettes also requires a lot of energy. In the case of charring, the
energy required for the process of charring is provided by the biomass
itself that is being charred. By subtracting the energy of the charcoal
from the energy in the original biomass, one can easily calculate the loss.
But in the case of the other two examples, the energy comes from external
sources and it is always treated by the processor as his best guarded
secret. Can anybody throw some light on the energy loss in making alcohol
and biomass briquettes? How much is the net gain in Energy in these two
products?
Yours
A.D.Karve

-- 
***
Dr. A.D. Karve
Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20120314/20caa658/attachment.html>