An evaluation of different kinetic models for determining the kinetic coefficients in sugar cane straw–clay ash/lime system

Abstract

The paper presents a comparative study in which different kinetic models were applied to describe the reaction kinetics of a mixture of sugar cane straw with 20 and 30% of clay, burned at 800 and 1000°C (SCSCA), and hydrated lime [calcium hydroxide (CH)]. Classical models, such as the Jander, Jander Modified and Zuravlev models were applied. These models were compared with a kinetic-diffusive model previously published by some of the present authors. The models were fitted to the experimental data by computerised methods, which allowed the computation of the kinetic parameters that rigorously characterise the pozzolanic activity of the materials. The results showed that Jander, Jander Modified and Zuravlev models did not describe the pozzolanic reaction kinetics in this system correctly, whereas the model proposed by the authors gave the best results with respect to fitting to the experimental data. This demonstrated that the model proposed by the authors was the most adequate for describing the reaction kinetics in the SCSCA system.