A Study of Biomass Torrefaction Process using CFD Simulation

Asma Sadiq, Naveed Ramzan

Abstract


The use of raw biomass as fuel is restricted due to its high moisture content, low bulk density, low calorific value, storage and transportation issue. Torrefaction has been proposed as a possible thermal pre-treatment of raw biomass to enhance its features. In this paper, a small-lab scale unit of the entrained flow torrefier was simulated using the Computational fluid dynamics simulation to analyze the behavior of various operational and design parameters on the biomass torrefaction process. The contours were developed and examined for discrete operational and design parameters such as velocity, turbulent viscosity, temperature distribution, particle ID profile and residence time of particles. These contours explicitly explain the variance of the parameters and particles in the 3-D geometry. The simulation finding shows that the torrefaction temperature obtained is 473-523 k as the experimentally quoted temperature for torrefaction is 503-523 k. Similarly, the residence time achieved lies between 1-15 minutes as the experimentally quoted residence time for torrefaction is 15-30 minutes depending upon the size of the unit.


Keywords


Biomass, Torrefaction, CFD, temperature contours, residence time contours

Full Text: JPIChE 45 (1) 2017 13 - 23

Published by Pakistan Institute of Chemical Engineers (PIChE)

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