Project
Title
Demonstrationsprojekt Arzneipflanzen (KAMEL); Erstellung eines Leitfadens für die Trocknung von Arznei- und Gewürzpflanzen
Acronym
Leitfaden Trocknung
Start
01.03.2016
End
30.04.2017
Contact
Partner
Agrarprodukte Ludwigshof e.G.
Summary
The objective of the guide is to provide essential information about efficient drying of medicinal and spice plants. Achieving maximum energy efficiency is crucial for ensuring an acceptable economic efficiency. Maximum exploitation of the dryer capacity during the harvesting season is a top priority. Different modes of dryer operation and changing weather conditions have much greater impacts on the specific thermal energy consumption than the drying behavior of individual plant species. Therefore, the respective part of the drying processes pertaining to the air side should first be optimized by implementing an effective strategy of control. Employing an efficient energy supply is then the second step.
One of the primary measures to improve energy use efficiency is partial recirculation of dryer outlet air. If optimized control of the recycled air ratio is realized, the elongation of the total drying duration can be limited to a negligible minimum. Other effective measures in batch-type drying include utilizing outlet air in subsequent dryers or rearranging partially dried produce on a smaller grate area for further drying. Any of these measures can lead to energy savings of more than 25 %.
Based on simulation results obtained from fixed-bed drying of chamomile flowers, different energy supply alternatives were analyzed. In case of continuous drying over several days, relatively small amount of energy can be saved by utilizing solar heat. In contrast, energy supply through the combination of a heat pump with a combined heat and power plant (CHPP) in addition to partial air recirculation led to primary energy savings of 73 %. Economic assessment found that the investment required for a controlled recirculation of dryer outlet air would be paid back in less than two years. Considering subsidies, utilization of CHPP waste heat, combination of heat pump and CHPP, and utilization of solar heat exhibited amortization periods approximately between six and ten years.
Funding
Bundesministerium für Ernährung und Landwirtschaft (BMEL)
Funding agency
Fachagentur Nachwachsende Rohstoffe e.V. (FNR)
Grant agreement number
22015612