Simple Procedure to Estimate Mass Transfer Coefficients from Uptake Curves on Activated Carbons

• Published in: Chemical engineering & technology Vol. 41; no. 8; pp. 1622 - 1630
• Main Authors: Magalhães Siqueira, Rafael, Vilarrasa-García, Enrique, Belo Torres, Antônio Eurico, Silva de Azevedo, Diana Cristina, Bastos-Neto, Moisés
• Format: Journal Article
• Language: English
• Published: Frankfurt Wiley Subscription Services, Inc 01.08.2018
• Subjects: Activated carbon; Adsorption; Coefficients; Column dynamics; Linear driving force; Mass transfer; Mass transfer coefficient; Molecular chains
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.201800091

A method based on the linear driving force (LDF) approximation is described to estimate the mass transfer coefficient of molecules adsorbing onto microporous carbons, by using independently measured uptake data. This parameter was determined from uptake curves derived from pressure increments during the measurement of isotherm data. To validate the method, simulations for batch uptake were performed and compared to the experimental data in order to obtain the values for the LDF constants. Such values were applied to predict breakthrough curves and compared to experimental data. The proposed method to estimate the LDF coefficient can be adequate to obtain a more physically meaningful value of the mass transfer coefficient. A simple procedure to estimate the mass transfer coefficients for CO2 and N2 in microporous activated carbon was developed based on uptake experiments typically used to obtain equilibrium isotherms. The estimated parameters helped to simulate breakthrough curves, which were compared to experimental data. An excellent match was observed, indicating the good reliablity of the presented method.