Research on procedural optimization and development of agricultural drying processes

Abstract

Drying is the most important post-harvest process for fast and safe preservation of agricultural products, but it is also energy-intensive at the same time. Agricultural drying is particularly energy-demanding for several reasons – high differences between harvest and storage moisture content, low drying temperatures, and low levels of pre-treatment due to sensitivity to thermal and mechanical stress. Well-established methods for increasing heat and mass transfer, such as surface enlargement and agitation of the bed material, are not applicable for many products. Therefore, farmers depend on optimum harvest windows and weather conditions as well as powerful drying systems in order to attain high product quality, to avoid deterioration, and to process large amounts of produce at the same time. Consequently agricultural process engineers have to compromise between gentle drying, energy efficiency and high drying capacity in order to approach optimum process quality for a specific crop. The current research activities of the Drying Group at ATB Potsdam addressing agricultural drying of grain are presented in this paper.