Ultimate Analysis of Biomass Fuel
Ultimate Analysis of Biomass Fuel
(OP)
I would like to get some clarification here. I am working on a project where I received two separate ultimate analysis of a biomass fuel.
The first result has ash, sulfur, carbon, hydrogen, nitrogen and oxygen add up to 100%.
The second result has moisture, ash, sulfur, carbon, hydrogen, nitrogen and oxygen add up to 100%.
The difference being whether moisture is part of it or not. I believe the first one is right. I did a google search and I saw some pages that include moisture and some that don't...
I do not have access to ASTM standards.
The first result has ash, sulfur, carbon, hydrogen, nitrogen and oxygen add up to 100%.
The second result has moisture, ash, sulfur, carbon, hydrogen, nitrogen and oxygen add up to 100%.
The difference being whether moisture is part of it or not. I believe the first one is right. I did a google search and I saw some pages that include moisture and some that don't...
I do not have access to ASTM standards.





RE: Ultimate Analysis of Biomass Fuel
I would recommend you use the ultimate analysis that includes the moisture (assuming it is from a valid source).
The ultimate analysis of coal usually (if not always) includes moisture and I see no reason to ignore the moisture in biomass.
If you are going to use the analysis in some stoichiometric combustion calculations, you should definitely include the moisture content.
Milton Beychok
(Visit me at www.air-dispersion.com)
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RE: Ultimate Analysis of Biomass Fuel
Once I size everything up and put an engineering factor on it, it probably won't make much of a difference, but on wetter fuels it will so I'd like to know in the future.
RE: Ultimate Analysis of Biomass Fuel
Now, if you ask me why, I am going to have to start clearing out some cob webs. If I remember, I think you need both for your combustion calculations.
Maybe someone who has done combustion calculations more recently than I have can answer that. (it has been almost 30 years for me and I don't think I want to remember why.
rmw
RE: Ultimate Analysis of Biomass Fuel
This being said, the fuel moisture must be evaporated and this will rob heat from the combustion. This lowers flame temperatures and, in practice, the amount of heat that can be recovered; the water vapor is lost up the stack.
The short answer: use the "as fired" analysis; the dry version doesn't tell the whole story.
RE: Ultimate Analysis of Biomass Fuel
I have two results from two different labs. Both tests show "as received" results. This should be the equivalent to the "as-fired" condition.
The calculations themselves are not a problem for me but I'm curious as to which one is right, because I think the oxygen level in the one might be wrong.
I don't have the results in front of me, but to provide an example. In test result #1 I have (ball park numbers only) - 35% C, 30% H, 5% ash, 0% N, 0% S, and therefore 30% oxygen. The results submitted for this test list about 10% moisture separately.
In the second I have 35% C, 30% H, 5% ash, 10% moisture, 0% N, 0% S, and therefore 20% oxygen.
RE: Ultimate Analysis of Biomass Fuel
- If what you want is to know how much fuel you have, an elemental analysis like this will include water. Substract it and you'll get the exact amount of fuel. This would be a quantitative analysis of the fuel.
-If you're evaluating heating capacity, or quality of the fuel, you have to include the water, as it will effect the ehating capacity of the fuel.
I think you should define what is your purpose for the analysis, what are you trying to achieve, and then decide if the water will play a factor or not.
as I said, 'ultimate analysis' might imply the purpose and I'm just putting my foot on my mouth with this post
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RE: Ultimate Analysis of Biomass Fuel
Usually, a fuel analysis is clear enough that you don't have to deduct one species from the sum of the others.
I know your numbers are from memory but 20% O2 seems low for biomass. Pls provide more info.
RE: Ultimate Analysis of Biomass Fuel
On the other hand , it is easier to estimate the efficiency of a biomass-fired boiler if the fuel is evaluated on a moisture free basis.
See the following link <http://www.woodgas.com/proximat.htm> for an example of the way that other countries treat biomass fuels vis a vis ultimate analysis.
RE: Ultimate Analysis of Biomass Fuel
Other biomass fuels have the same considerations that have to be taken into account. As davefitz notes, sorting all of that on an "as fired" basis would be a nightmare, so the basis for comparison is best done on a "bone dry" basis.
rmw
RE: Ultimate Analysis of Biomass Fuel
RE: Ultimate Analysis of Biomass Fuel
Although, who knows, maybe that is where the discrepancy was.
RE: Ultimate Analysis of Biomass Fuel
It contains an ultimate analysis of MSW.
The first time you run it you may have to tell it to open the file with TBook, it will be in your Factbook folder.
It also shows the HHV of most types of MSW like paper, plastic, wood,and food etc.
RE: Ultimate Analysis of Biomass Fuel