[Stoves] Metals in biofuels

[frank]

Tom and stovers,

I am trying to work up a test procedure to predict toxic emissions and 
potential of fouling.


1) I do an acid digest (HNO3+HCl) then ICP 
(Al,As,B,Ca,Cd,Co,Cr,Cu,Fe,K,Mg,Mn,Mo,Na,Ni,Pb,Se,Zn,P) on a ground 
sample of biomass. Also run IC (Cl, NO3, SO4, PO4) on a water extract.

2) Char a sample in a pipe (no oxygen) at 400 deg C for two hours

3) Grind and acid digest a sub-sample of char followed with ICP and IC

4) Ash the char at 550 deg C until white

5) Acid digest a sub-sample of ash. Measure CO2 produced and run ICP and IC

7) Take the ash to 950 deg C and determine if fused together.

The difference between test values (1) and (3) are elements that have 
easily gone off with emissions and may be potential health problems.
The difference in elements between (3) and (5) are constituents that go 
off at a higher temperature.
The ash analysis (5) produced below 600 deg C  below fusion(?)  will 
tell what is in the ash and one can predict if at a high temperature 
there will be fouling.
Carbonates (as CO2) determined at (5) will tell us how much carbon is 
now inorganic and is trapped in the ash.
Taking the ash to 950 deg C (7) and checking the ash for melt will tell 
us how well the prediction worked.

Looks like a lot of work but with the equipment we have these days it is 
not all that much  I am going through your paper to try to come up with 
predictions based on the element.   data. Don't think all this is all 
that important on the small stoves we now use but I am thinking along 
the lines of using 'fuel socks' that continuous feed the stove for hours 
on end and fouling may then be a problem. It could be a simple and cheap 
procedure to help formulate biofuels.

Suggestions appreciated

Frank


-- 
Frank Shields
Soil Control Lab
42 Hangar way
Watsonville, CA  95076
(831) 724-5422 tel
(831) 724-3188 fax
frank at compostlab.com
www.compostlab.com