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Chitosan stuffs atmospheric freeze‐drying kinetics
Author(s) -
Stawczyk Jan,
Li Sheng,
Modrzejewska Zofia
Publication year - 2007
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.54
Subject(s) - freeze drying , sublimation (psychology) , chitosan , mass transfer , chemical engineering , chemistry , kinetics , convection , heat transfer , materials science , thermodynamics , chromatography , physics , engineering , psychology , quantum mechanics , psychotherapist
Atmospheric freeze drying (AFD) is a solution that combines the advantages of both freeze drying (high product quality) and convective heat pump drying (lower process costs). A computer controlled atmospheric freeze dryer was designed, built and tested in the Department of Heat and Mass Transfer, Technical University of Łódź. The effect of AFD kinetics of chitosan membrane and white and brown chitosan granules have been investigated, and the classical constant and falling drying rate periods were determined at different process temperatures. Drying process was controlled by surface ice sublimation during the overall process. The surface structure was studied via atomic force microscopy and the structural characteristics of chitosan membrane; volume and surface area of micropores and mesopores were compared with the results of vacuum freeze drying and convective drying. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.