Dear Frank
----- Original Message -----
From: "Frank Shields" <[email protected]>
To: "'Discussion of biomass cooking stoves'"
<[email protected]>; "'SARBAGYA TULADHAR'"
<[email protected]>
Sent: Monday, March 19, 2012 1:48 PM
Subject: Re: [Stoves] Cleaning Dung
Paul, and stovers,
<snip>
6. Also, is what is washed from dung better, same, or worse for energy
content than what is left in the washed dung? This has probably been
studied, but I do not know that answer. Anybody?
# The Dung from Ruminants is the end result of well ground vegetative matter
being very fully digested. Basically, the animal's digestive system is able
to remove about 90% of the cellulose and hemi-cellulose content in the feed,
leaving behind the "undigestables", which are very high in Lignin. Lignin
has a significantly higher content calorific value than cellulose and
hemi-cellulose, so that "washed dung" will inherently have a higher
calorific value than "dirty dung".
# What is removed from dung in the washing process are:
--> Proteins
--> Micro nutrients
--> Hormonal metabolites
--> Nitrates
--> Chlorides
--> Sodium
--> Potassium
and probably a whole lot more!!
# All the above "wash water constitutents, except when possibly used in
excess, are excellent Fertilizer additions to marginal soils. Not only does
the washing prevent destruction of a valuable fertilizer resource, but the
washed dung makes a superior fuel, for the following reasons:
1: It has a higher calorific value
2: Chlorides interfere with combustion, and removal of chloride content can
result in improved combustion.
3: Removal of the Chloride from the fuel removes the dioxin hazard
associated with burning fuels containing chlorides.
(I suspect that a large percentage of IAQ related illnesses in dung burning
situations are due to the contained chlorides.)
# I have been advocating "Dung Washing" and utilization of the washings for
"Fertigation" for about 6 years now. I am very pleased to see people
actually doing it now. I would also encourage greater use of the "Copper
Wire Test for Halogens", which I suggested at about that time, to detect
likely dioxin conditions. Hopefully, the Subject is now becoming fashionable
enough such that sokeone will do a PhD on "The Merits and Consequences of
Dung Washing."
# Chicken Dung, or manure, or bedding material, should also be washed , for
the same reasons, if it is to be used for fuel purposes, or biochar
manufacture (ie, 'Chicken Char.") I suspect that most of the chlorides will
report to the pyrolysis gas and liquids fraction, where they will form
dioxins. There could be a great danger to the whole Biochar Industry, if the
pyrolysis products from a Chicken Char" operation are tested for dioxins,
and if there is an "Environmental Over-Reaction".
Best wishes,
Kevin
[*] From my dung washing experience (along with compost, AD digestate
etc.)
what is real important is how the material is handled. If it is allowed to
pick up dirt and sand (does so very easily) and if that remains on the
screen could greatly lower the energy value. Compost typically has 50% ash
and most of that is dirt and stones. Dung can have much more.
Also the amount loss during washing depends on what the animal eats and
its
digestion system. Cow will mostly get washed out where horse will have a
lot
left for use.
I think handling is most important as to final quality.
Frank
Frank Shields
42 Hangar Way
Watsonville, CA 95076
(831) 724-5244 tel
(831) 724-3188 fax
[email protected]
.
_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
[email protected]
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
for more Biomass Cooking Stoves, News and Information see our web site:
http://www.bioenergylists.org/
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1913 / Virus Database: 2114/4880 - Release Date: 03/19/12
_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
[email protected]
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
for more Biomass Cooking Stoves, News and Information see our web site:
http://www.bioenergylists.org/
