A Moisture Transmembrane Transfer Model for Pore Network Simulation of Plant Materials Drying

Abstract

The drying of plant materials with cellular tissue is often viewed as drying of porous media that is assumed to consist of cell cytoskeleton and intercellular space. Various approaches have been reported in the literature to describe heat and mass transfer during drying of such porous materials. However, the fact remains that the water in a cellular tissue is mostly intracellular and it should be driven out of the cells across cell membranes before transporting in cell gaps, as in a general porous media. In the present study, the transport process of moisture in a cellular tissue was analyzed. A mathematical model for moisture transport across the cell membrane was established, which was correlated to a self-developed, dual-scale pore network model (cell and pore network) for drying of plant materials. The relationship between mass volumetric flux and average intracellular moisture content was developed based on the microscopic images and the drying experiments.

Keywords:

• Isothermal drying
• Mass transfer model
• Moisture transmembrane transport
• Onion
• Porous media

ACKNOWLEDGMENT

The work was financially supported by the National Natural Science Foundation of China (No. 51076163).