Pyrolysis of Centimeter-Scale Woody Biomass Particles: Kinetic Modeling and Experimental Validation

Abstract

Pyrolysis of centimeter-scale wood particles is of practical interest and provides a sensitive test of pyrolysis models, especially their thermochemistry. In this paper we present an updated comprehensive pyrolysis model including chemical reactions and transport of heat and species, implemented independently in two different software environments. Results of the model are compared to experimental results of three independent sets of centimeter-scale experiments. Temperatures, mass losses, and rate of production of several gaseous and light tar species are included in the comparisons. Predictions and experiments agree qualitatively and in most cases have reasonable quantitative agreement. We also report comparisons of model predictions to literature data obtained in other regimes (thermogravimetric analysis and omogeneous tar cracking) in order to demonstrate that predictive capabilities of the model have not been compromised by the modifications presented here

Measuring biomass fast pyrolysis kinetics: State of the art

“…When Bi <1, external heat transfer is the pyrolysis controlling parameter. In the case of Py <1 and Bi >1, thermal gradients exist in biomass particles, and therefore, reactions occur only in the thin region near the particle surface (Corbetta et al, ; Mettler, Paulsen, Vlachos, & Dauenhauer, ; Paulsen et al, ). When Pe >1 the rate of diffusion of bio‐oil and gases through the reacting biomass particle is slower than the convective mass transfer.…”

Application of a detailed biomass pyrolysis kinetic scheme to hardwood and softwood torrefaction

“…It is based on the scheme developed by Ranzi et al [12] for pyrolysis of small ash free biomass particles (i.e., primary pyrolysis) called from now on original scheme. A recent update of this scheme, which has not been employed in this work, was presented by Corbetta et al [14]. Biomass consists of cellulose, hemicellulose and 3 types of lignin which independently decompose and the volatiles are represented by 20 species, including main permanent gases and condensable species.…”

“…We can conclude that mass loss of lignocellulosic biomass torrefaction can be also predicted with this detailed kinetic scheme, although certain deviations are present at very low temperatures. Corbetta et al [14] have already shown that the Ranzi scheme is able to predict mass loss evolution of cellulose, hemicellulose and lignin under torrefaction conditions.…”

Segregation of wood particles in a bubbling fluidized bed

“…The segregation of thick wood samples such as chips or pellets in sand beds has been less studied compared to pyrolysis/gasification/ combustion kinetics [4][5][6][7][8][9][10][11][12][13][14][15] or fluidized bed hydrodynamics [1,3,[16][17][18][19][20][21]. Some studies conducted on solid mixing in fluidized beds have focused on particles with the same density but different shapes or diameters [22][23][24] or particles with the same shape but different densities [22].…”