MODELING OF SOLID-LIQUID ADSORPTION - EFFECTS OF ADSORBENT HETEROGENEITY

• Type: Article in International Scientific Journal
• Date: 1993

Authors

LEITAO, A (Author) Other; Alírio Rodrigues (Author) FEUP

Journal

Title: Chemical Engineering Journal and the Biochemical Engineering Journal

Vol. 51

Pages: 159-166

ISSN: 0923-0467

Publisher: Elsevier B.V.

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 1 Citation

Other information

Authenticus ID: P-001-MZQ

DOI: 10.1016/0300-9467(93)80026-k

Abstract (EN): Effects of adsorbent heterogeneity on the adsorption of cobalt phthalocyanine dye on activated carbon have been studied. Adsorption experiments were carried Out by varying the temperature and adsorbent mass in batch adsorbers and, in addition, the adsorbent particle size and fluid flow rate in a continuous stirred tank reactor (CSTR)-type adsorber in order to investigate the equilibrium and the kinetics of adsorption. The Brunauer-Emmett-Teller (BET), Langmuir with uniform distribution (LUD) and Langmuir-Freundlich equations are able to represent the equilibrium data with similar accuracy within the range of measurements. Reasonably large values of the heterogeneity parameter (2.69-2.86) show that the carbon surface is energetically heterogeneous. A mathematical model that describes the adsorption dynamics, including film-, pore- and concentration-dependent surface diffusion on an energetically and structurally heterogeneous adsorbent, is presented here and fitted to the experimental concentration vs. time curves obtained in the continuously stirred tank adsorber. Structural heterogeneity of the carbon, if not accounted for in the kinetic model, can be responsible for the very strong concentration dependence of the surface diffusion coefficient and for the variation in the parameter D(o) with particle size and adsorber porosity as shown in this work.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8