Kinetics of reactions involved in pvrolvsis of cellulose II. The modified kilzer‐bioid model

Abstract

At temperatures below 300°C, it has been shown that the pyrolysis of cellulose can be modeled in terms of a modified Kilzer‐Broido ((K‐B) Model. According to this model, cellulose decomposes via two competitive reactions, a dehydration reaction to form anhydrocellulose and a depolymerization reaction to form levoglucosan. Anhydrocellulose later decomposes to chars and gaseous products via two competitive reactions. Arrhenius parameters and a technique of estimating empirical constants from experimental data for the K‐B type reactions are presented. Comparison of the ability of the modified K‐B model and the three reaction model to predict weight loss, product yields and heat pretreated results are also made.

Feedback processes in cellulose thermal decomposition: implications for fire-retarding strategies and treatments

“…In the big picture that has taken shape from these results and from associated modelling studies (for example, see [8,9,10,11,12,13] and the reviews in [14] and [15]) formation of volatiles and char are seen to be reciprocally linked to some extent.…”

The Overview of Thermal Decomposition of Cellulose in Lignocellulosic Biomass

“…Broido and Weinstein (1971) [27] This Broido' s kinetic scheme is re-examined by Argawal [13], revealing that the rates of anhydrocellulose formation are comparable to those of the depolymerization process only in one case for temperatures of ~ 270 o C in the isothermal, fixed-bed conditions. Then, the mechanism is approved through the isothermal, fluid-bed experiments in the temperature range 250-300 o C, providing a complete set of kinetic data for the Broido model [13]. It is worthily noting that the formation of the anhydrocellulose as an intermediate product is undetectable in the experiments, and no kinetic data for the char forming reaction are reported in the above publications.…”

Kinetics of reactions involved in pyrolysis of cellulose I. The three reaction model

“…The three reaction model is not "mechanistic" as it does not explain the formation of anhydrocellulose at temperatures below 300°C. Some low temperature "mechanistic" aspects of cellulose pyrolysis reactions are discussed in Part I1 of this series (Agrawal, 1988).…”