The freeze‐drying process is studied under various operational policies through the use of a sorption‐sublimation model. The operational policy that provides the shortest drying times keeps the pressure at its lowest value. The upper and lower heating plates are independently controlled so that the material constraints are encountered and held throughout the free water removal phase. Under certain conditions, and for the case of samples of small thickness, the sorbed water profiles may have segments whose bound water concentrations are higher than those at the start of the free water removal phase. It is shown that the criterion used in terminating the freeze‐drying process is of extreme importance, since it may lead to an undesirable sorbed water profile which may deteriorate the quality of the dried product. Copyright © 1985 American Institute of Chemical Engineers


Chemical and Biochemical Engineering

Publication Status

Full Access

International Standard Serial Number (ISSN)

1547-5905; 0001-1541

Document Type

Article - Journal

Document Version


File Type





© 2023 Wiley; American Institute of Chemical Engineers (AIChE), All rights reserved.

Publication Date

01 Jan 1985