[Stoves] Metals in biofuels

[frank]

Tom,

A few questions:

I noticed boron was not included but boron is a big factor in glass 
making. Just wondering if it was looked into?
Also; titanium is included but that seems to be a rare constituent in 
biomass. Where would that come from? Is that really important?
Wondering if carbonates are only in the ash where a carbonate is added 
(lime) or if it can form at the right temperature? I find a lot of 
carbonates in ash samples.
If dirt is included in the biomass is the oxides that are already formed 
at the start a problem with slagging? or is it neutral and the problems 
come during elements in the biomass structure converting to oxides at 
the high heat?
Is Si in soil (quartz) a problem or only the Si that has been taken up 
by plants (phytoliths)?
How is oxygen directly measured?

I think we should also add lead, arsenic and cadmium, perhaps zinc and 
selenium as toxins that come from treated wood, plant accumulation and 
additives that make toxic emissions.

I am thinking (hoping) that only the elements that dissolve in a hot 
acid digest along with sulfate, chloride and phosphate is important for 
us and not the 'rock' material left behind in the acid treatment when 
predicting problems.

Thanks - great report!  My head a centimeter bigger.

Frank



 
 






Tom Miles wrote:

>Frank,
>
>For evaluating potential problems for slagging and fouling in gasifiers and
>combustors (e.g. stoves) we use ten elements in the ash reported as oxides:
>
>Silica (SiO2)
>Aluminum    (Al)
>Iron    (Fe)
>Titanium (TiO2)
>Phosphorous (P2O5)
>Calcium (CaO)
>Magnesium (MgO)
>Sulfur (SO3)
>Sodium (Na2O)
>Potassium (K2O)
>
>Plus
>Chloride (Cl)
>Carbon Dioxide (CO2) is measured to estimate losses on fusion. 
>
>We measure total chloride in the fuel and of source sulfur. These elements
>volatilize during combustion and can cause fusion and deposits. 
>
>You can see how we use these analyses in the report, "Alkali Deposits in
>Biomass Boiler", TRM Miles 1995 lined from my website www.trmiles.com or
>directly at http://www.trmiles.com/alkali/alkali.htm
>
>Many thanks for your help with the Gasifier Experimenters Kit (GEK) at ETHOS
>this weekend. It was a big distraction for Charlie to set it up but I think
>it was worthwhile. 
>
>Kind regards,
>
>Tom
>  
>  
> 
>
>-----Original Message-----
>From: stoves-bounces at listserv.repp.org
>[mailto:stoves-bounces at listserv.repp.org] On Behalf Of frank
>Sent: Tuesday, January 27, 2009 4:35 PM
>To: Discussion of biomass cooking stoves
>Subject: [Stoves] Metals in biofuels
>
>
>Dear Stovers, charcoal makers and brick makers,
>
>Of the list of elements below I am wanting to know the ones that would 
>be of interest in regards to causing problems, volatile toxins and of 
>nutrient interest.
>I have already added As, Cd, Pb, Zn, to my list for possible toxins.
>I have added Ca, Mg, K, P for possible nutrients in left over char and ash
>I have added Na, and K that may be problems in making an ash that  forms 
>blocks (?).
>
>Any comments of problems or concern or interest of the following will 
>help me to put together a test program for testing biofuels.
>
>Thanks (again)
>
>Frank
>
>Aluminum    (Al)
>Boron    (B)
>Cobalt    (Co)
>Chromium    (Cr)
>Copper    (Cu)
>Iron    (Fe)
>Manganese    (Mn)
>Molybdenum    (Mo)
>Nickel    (Ni)
>Selenium    (Se)
>Chloride (Cl)
>Nitrate (NO3)
>Phosphate (PO4)
>Sulfate (SO4)
>
>
>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
>
>
>
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>
>
>
>
>  
>

-- 
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