Kindly anyone know how to calculate empirical formula for a biochar or activated carbon with the help of C, H, N and O content. I did CHNS analysis of my samples and got the C, H, N, and O contents (in %). What should i need to do for derive the empirical formula of biochar?
Example (d.a.f.):
C=72 wt% => 72 g / 12 g/mol= 6 mol
H=10 wt.% => 10 g / 1 g/mol = 10 mol
N=1.4 wt% => 1.4 g / 14 g/mol = 0.1 mol
O=16.6 wt% => 16.6 g / 16 g/mol = 1 mol
Empirical formula: C60H100NO10
The empirical formula is the proportion on an atomic mass basis in compounds; consequently, it is informative for compounds but much less so for solids of variable composition such as biochar
Example (d.a.f.):
C=72 wt% => 72 g / 12 g/mol= 6 mol
H=10 wt.% => 10 g / 1 g/mol = 10 mol
N=1.4 wt% => 1.4 g / 14 g/mol = 0.1 mol
O=16.6 wt% => 16.6 g / 16 g/mol = 1 mol
Empirical formula: C60H100NO10
Most researcher present biochar with its elemental analysis, C O H S N. It is not necessary to come up with chemical formula like other organic compound.
Hi Yulin Patrick Zheng , in my opinion the empirical formula can be useful for developing the stoichiometric equation to help describe the overall reaction. It is then possible to predict/estimate the enthalpy of the reaction and compare it with actual measurements.
The stoichiometric equation can also be used for mass balance purposes. If the amount of carbon going into the process is similar to the amount coming out (as syngas, bio-oil and biochar) then our measurements (e.g. CHNS for biochar, GC for bio-oil and syngas) can be considered correct.
Researchers trying to elucidate the molecular structure of biochar also need to ensure that their proposed molecular structure is in reasonable agreement with the empirical formula.
Finally one can predict the theoretical equivalence ratio (Article Improved Gasification of Rice Husks for Optimized Biochar Pr...
) and compare it with experimental values.- Badges
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