Kinetic study on the thermal dehydration of CaCO3 · H2O by the master plots method

✍ Scribed by Tang Wanjun; Chen Donghua; Wang Cunxin

• Publisher: American Institute of Chemical Engineers
• Year: 2006
• Tongue: English
• Weight: 316 KB
• Volume: 52
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.10801

✦ Synopsis

Abstract

Thermal dehydration process of calcium oxalate monohydrate, CaC~2~O~4~ · H~2~O, was reinvestigated from a viewpoint of reaction kinetics. On the basis of data of thermogravimetry, kinetic analysis was performed under nonisothermal conditions using an integral composite procedure, which includes a integral isoconversional method and an integral master plots method. The results of the integral isoconversional method of TGA data at various heating rates suggested that dehydration of CaC~2~O~4~ · H~2~O followed a single step with an activation energy of 99.02 ± 2.61 kJ/mol, and from the master plots method, the reaction was described by an R~n~ model. Finally, it was estimated that the pre‐exponential factor A = (2.82 ± 1.81) ×10^9^ s^−1^, and the kinetic exponent n = 2.3 ± 0.2. The results of nonisothermal kinetic analysis of the thermal dehydration reactions of CaC~2~O~4~ · H~2~O suggested that the integral composite procedure be very successful in evaluating kinetic parameters and describing kinetic model of solid‐state reactions. © 2006 American Institute of Chemical Engineers AIChE J, 2006