Recap of the NEFI Technology Talk: Drying Processes in Industry

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by Oxana Schmidt

On October 12, 2023, the NEFI Technology Talk on Drying Processes in Industry captivated a diverse and engaged audience in a dynamic online event. With over 60 enthusiastic participants, the Technology Talk, moderated by our NEFI expert Veronika Wilk (AIT Austrian Institute of Technology, Center for Energy), delved into the crucial role of drying processes in industrial settings, a sector that significantly contributes to industrial energy consumption.

Keynote: Energy Efficiency in Industrial Drying Processes

The keynote by Michael Lauermann (AIT Austrian Institute of Technology, Center for Energy) underscored the enduring significance of drying as a preservation technology spanning over 20 different sectors. He outlined the challenges inherent in drying processes, emphasising the pivotal role of energy efficiency. Michael Lauermann highlighted that while the theoretical minimum energy required for convective drying is the evaporation energy of water (2258 kJ/kg), real-world dryers require additional energy to account for various factors like heat transfer, system loss, drying agent loss and product-specific binding energy, collectively referred to as 'drying energy'. Lauermann introduced various types of dryers and discussed the disparity between expected and actual energy efficiency, often stemming from improper operation and design.

To enhance efficiency, Lauermann identified an array of methods, from heat exchangers to advanced control, superheated steam, multi-stage drying, and the promising integration of heat pumps. These technologies offer different levels of potential to boost energy efficiency, contingent on the availability of sensors and robust process control models.

Diverse Perspectives on Industrial Drying

The event featured a diverse range of perspectives from industrial experts:

Food Drying with a Focus on Renewable Energy: Juma Haydary from STU Bratislava addressed the energy-intensive nature of food drying and stressed the importance of reducing water activity to curb microorganism activity. He emphasized factors like temperature and air velocity in the drying process and the use of mathematical models for predicting drying kinetics. Haydary also explored indirect solar drying as a sustainable approach.

Drying of Herbs: Wolfgang Weiss from AEE-Intec introduced the SolSorpDry project and discussed the unique challenges of drying herbs. He highlighted the sensitivity of herbs to drying temperatures and shared ongoing efforts to enhance energy efficiency without compromising product quality.

Near-Infrared Product Moisture Sensors: Sebastian Friedl from RECENDT unveiled the NEFI EDDY - Enhanced Drying project, focusing on inline product moisture measurements using near-infrared spectroscopy. This technology offers real-time automated measurements and provides additional insights into product composition, such as protein and fat content.

Industrial Innovations

Two industry experts, Raphael Priesner from Agrana and Stefan Puskas from Wienerberger, presented innovative approaches to industrial drying:

Food Ingredients Drying: Raphael Priesner detailed the importance of industrial-scale drying for preservation and cost reduction, along with the ambitious decarbonisation goals of the Agrana Group, aiming for net-zero emissions by 2040.

Brick Drying: Stefan Puskas introduced the concept of using heat pumps to reduce the specific air consumption in brick drying processes. He highlighted the challenges of controlling hot air flow and optimising the overall manufacturing process.

A Shift in Paradigm

In conclusion, the NEFI Technology Talk showcased the evolving landscape of drying processes with a strong emphasis on improving energy efficiency and adopting innovative technologies. Discussions ranged from enhancing existing processes to exploring entirely new paradigms, such as seasonal drying and electrification, echoing the industry's commitment to sustainability.

A Mentimeter survey, conducted at the end of the event, reflected the attendees' key takeaways, including insights, the necessity for optimisation and the importance of inline monitoring.

The event left attendees inspired and enlightened, providing valuable insights into the future of drying processes in the industry.

To the presentations (PDF-files in English)