A new mathematical model to simulate sorption, desorption and hysteresis of stored canola during aeration

Abstract

A new mathematical model, based on energy and mass conservation, to simulate grain aeration was developed. The developed model considered the sorption, desorption, and hysteresis of canola and the heat transfer in the normal direction to the airflow at the bin walls. The developed model was compared with a published model, which was verified by different research groups. The main difference between the new model and the published models was that the new model determined the isotherm status including hysteresis of the aerated canola by evaluating the vapor pressure. Canola temperature, RH, and moisture content measured during aeration inside grain columns were used to verify the developed model. The grain columns (0.2 m inner diameter, 1.5 m high) were filled with 11.8% moisture content (wet basis) canola and aerated at 0.00275 m/s superficial velocity with the air temperature of 10, 15, and 20 °C and relative humidity of 75 ± 10%. The developed new model did not over- or under-predict the moisture contents in most parts of the columns, and had a better prediction of canola moisture content than that of the published model. Including the hysteresis evaluation in the developed model notably increased the model prediction accuracy.

Keywords:

• Aeration
• mathematical model
• hysteresis
• canola
• drying and rewetting

Additional information

Funding

The authors thank the Natural Sciences and Engineering Research Council of Canada for partial funding of this study as well as the Canada Foundation for Innovation, the Manitoba Research Innovation Fund, and several other partners for creating the research infrastructure. We gratefully acknowledge Mr. Dale Bourns and Mr. Matt McDonald for their help in fabricating the grain columns.