[Stoves] Testing biomass using a TGA

[Frank Shields]

Greeting Stovers,


All in the TGA:
Take a sample of biomass in air and dry at 200c. (moisture)
Flush out the air and replace with nitrogen and heat to 700C (pyrolysis gases)
Flush out the nitrogen and replace with butane at 25c and measure the butane uptake (butane activity)
*Flush out the butane with air or oxygen and ash at 550c to determine (char and ash content). 

* this step I am not sure because there may be a chance if the butane is not all flushed out or the butane absorbed coming out can make an explosive mixture in the TGA. But if air is flowing while being heated this is a low possibility I am thinking.


This will give:
% moisture
% Pyrolyzes gases
% char
% ash
% butane activity

If we know the total energy on a dry sample (using a calorimeter) and we can get a good value on the pure char fraction (available) and the ash fraction (available) we can determine the energy in the volatile organics. 

This will give a good energy distribution analysis in the biomass and the potential of the biomass to make a char with good activity values. Butane can be replaced with any number of gases. For example I used methane and found dried Canadian peat to take up some methane thinking it could be used to absorb methane using peat natural in the tundra and leaving nothing more than peat char naturally found after a wild fire. I have used gasoline vapors to determine the weight the char can remove these vapors. Ammonia I have used. I did not have a TGA available when I was working ( using pipes) but think there are good possibilities.   



Regards

Frank