How to determine the coefficients in the equation of biomass pyrolysis

MFiX How to
#1

Hi everyone,

I would like to run a case for biomass gasification with MFIX-DEM. The case I focus on is the one published in this reference (Particle behaviours of biomass gasification in a bubbling fluidized bed - ScienceDirect, https://doi.org/10.1016/j.cej.2021.131847). My question is about the reaction expression for biomass pyrolysis below.

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I am not sure how to determine these coefficients, from α1 to α7. In this paper, it mentions that the coefficient of each product comes from the proximate analysis and ultimate analysis from Redirecting which are attached below. The Mol. Weight for biomass can assume to be 100 according to a tutorial for a TFM case in MFIX 21.4.

Note: There is also a reaction expression for pyrolysis in this tutorial case mentioned above and I have learnt this case. However, the reaction expression for pyrolysis is not the same and may not meet ∑α_i = 1.

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Thanks for your help.

#2

So I would use the the proximate analysis to determine the a6 (char), a7 (ash), and a5(Moisture) coefficients. The volatile composition is much harder to approximate. You have the total amount in the proximate analysis but not the break down of the individual gas species.

There are models that try to predict what the composition should be like:

C3M: Is a tool that could be used to take the ultimate and proximate analysis and convert them to the molar coefficients: C3M - NETL Multiphase Flow Science

#3

Much thanks Justin, and I will apply to download C3M.