Electrohydrodynamics for non-thermal, low-energy dehydration of soft, heat-sensitive materials

Type. Bilateral project with Migros Genossenschafts-Bund

Funding. This project is funded by the ETH Foundation (sponsored by Migros-Genossenschafts-Bund via World Food System Center)

Duration. 3 years (2019-2022)

Collaborations. M-Industry

Contact. Thijs Defraeye (principal investigator)

Staff.  (Ph.D. student at ETH Zurich)

Project background:

The principle behind electrohydrodynamic (EHD) drying is that airflow (so-called ionic wind) is generated by means of corona discharge. This ionic wind enhances heat and mass transfer from any wet material that is placed in this airflow field. As electrohydrodynamic drying is a non-thermal technology, it is particularly attractive to dehydrate heat-sensitive products, such as plant-based foods (e.g. fruits and vegetables). Compared to conventional convective drying, it has been reported to reduce drying time, reduce product shrinkage, increase rehydration capacity, improve (soften) texture, and preserve color and flavor better. It is also found to preserve better nutritional content (e.g. vitamin C). The main aim of this project is to design a sustainable drying process that can deliver affordable, appealing, and nutritious dried food. We will approach this aim by using all the three scientific tools namely, multiphysics modeling and simulation, experimental testing on an EHD dryer setup, and theoretical analysis. 

Project-related publications:

  • Iranshahi K., Martynenko A., Defraeye T. (2020), Cutting-down the energy consumption of electrohydrodynamic drying by optimization mesh collector electrode, Energy, 118168. DOI  
  • Iranshahi K., Onwude D.I., Martynenko A., Defraeye T. (2021), Dehydration mechanisms in electrohydrodynamic drying of plant-based foods, Food and Bioproducts Processing. DOI
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EHD drying of apple slices
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EHD drying; How does it work?
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IR thermography of EHD drying of apple slices
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a) Schematic of EHDD setup with a wire-to-mesh configuration; b) water transport together with the different cellular environment in which the water resides (figure not to scale).
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a)Schematic illustration of the experimental setup, b) Experimental setup together with the electrodes configuration and plate vs. mesh collectors

Funding agency:





PhD student

Kamran Iranshahi