Modelling of the pyrolysis of biomass particles. Studies on kinetics, thermal and heat transfer effects

Abstract

The present work provides a rationally‐based model to describe the pyrolysis of a single solid particle of biomass. As the phenomena governing the pyrolysis of a biomass particle are both chemical (primary and secondary reactions) and physical (mainly heat transfer phenomena), the presented model couples heat transport with chemical kinetics. The thermal properties included in the model are considered to be linear functions of temperature and conversion, and have been estimated from literature data or by fitting the model with experimental data. The heat of reaction has been found to be represented by two values: one endothermic, which prevails at low conversions and the other exothermic, which prevails at high conversions. Pyrolysis phenomena have been simulated by a scheme consisting of two parallel reactions and a third reaction for the secondary interactions between charcoal and volatiles. The model predictions are in agreement with experimental data regarding temperature and mass‐loss histories of biomass particles over a wide range of pyrolysis conditions.

Determination of acoustic fields in acidic suspensions of peanut shell during pretreatment with high-intensity ultrasound

“…Specific heat as a function of multiple variables may be incorporated into the energy balance equation in order to predict the temperature profiles with great accuracy (Koufopanos et al, 1991). Similar equations were obtained for lignocellulosic waste materials, such as banana flowerstalk (Villa-Vélez et al, 2015a) and woods (Koufopanos et al, 1991). In general terms, the three models showed good and simple descriptions of the experimental data as functions of all parameters studied (R 2 adj > 0.967).…”

“…Higher values of c p were encountered for less concentrated suspensions since dry biomass has a lower specific heat than water (Collazo et al, 2012). Specific heat as a function of multiple variables may be incorporated into the energy balance equation in order to predict the temperature profiles with great accuracy (Koufopanos et al, 1991). Similar equations were obtained for lignocellulosic waste materials, such as banana flowerstalk (Villa-Vélez et al, 2015a) and woods (Koufopanos et al, 1991).…”

Analytical Investigations of Kinetic and Heat Transfer in Slow Pyrolysis of a Biomass Particle

“…Temperature-dependent property variation was also studied by Matsumoto et al (1969), Kung (1972), Maa and Bailie (1973), Kansa et al (1977), Chan et al 1985). Multi-step reaction schemes have been presented by Tinney (1965), Kung (1972), Chan et al (1985) and Koufopanos et al (1991). The heat of reaction of pyrolysis have been modelled by Lee et al (1976), while the effect of anisotropy of the pyrolysing medium has been considered by Kansa et al (1977).…”

“…Villermaux et al (1986) presented a Volatilization Thermal Penetration model (VTP) for any kind of solid reaction where volatilization is controlled by heat conduction from the outer surface. On the modeling of pyrolysis of biomass particle, particularly on the studies of the kinetic, thermal and heat transfer effects, Koufopanos et al (1991) assumed the pyrolysis process to be primary and secondary kinetic reactions. Di Blasi (1993) analysed the effects of convection and secondary reactions within porous solid fuels undergoing pyrolysis.…”

Isothermal Carbonization of Wood Particle: Application of the Lattice Boltzmann Method

“…This model gave satisfaction only for wood particles whose diameters are lower than 20mm. Koufopanos et al [4] defined a model in which they coupled conduction heat transfer with chemical kinetics. They concluded that the reactions heat can be represented by endothermic or exothermic values according to the conversion rate.…”