COMPARISON OF KINETIC MODELS FOR THE AQUEOUS SOLID-LIQUID EXTRACTION OF TILIA SAPWOOD IN A CONTINUOUS STIRRED TANK REACTOR

Abstract

The kinetic study of the aqueous extraction of Tilia sapwood was based on temperature, while all the other factors were kept constant. Several models were used and compared to explain the kinetics of the aqueous solid-liquid extraction of Tilia sapwood. For each model, the rate constant, the equilibrium extraction capacity, and the initial extraction rate were evaluated to analyze the suitability of these kinetic models to describe the leaching process for temperatures ranging from 313 to 363 K. The pseudo first-order model could not be applied during the whole of the process. The Elovich model provided a good degree of correlation (from 0.929 to 0.988) and could be applied all along the extraction process. The pseudo second-order model was satisfactorily applied, with coefficients of correlation over 0.998, showing that it perfectly described the process. A physical explanation of these models was finally proposed.

Keywords:

• Elovich model
• First-order model
• Kinetics
• Leaching
• Second-order model
• Tilia sapwood

Acknowledgments

We would like to thank Dr. Renaud Caplan of the Laboratoire des Matériaux & Mineraux of Conservatoire National des Arts et Métiers (Paris) for the determination of specific area and Jean Alexandre of the Laboratoire de Chimie & Génie des Procédés of Ecole Centrale de Paris for the determination of ash content.

Notes

*These values were obtained from Microsoft Excel®.

*These values were obtained from Microsoft Excel®.

*These values were obtained from Microsoft Excel®.

*These values were obtained from Microsoft Excel®.

*These values were obtained from Microsoft Excel®.