A new technology to freeze-dry products faster

Start-up Lyophitech has developed a dynamic freeze dryer that can freeze-dry products between 4 and 5 times faster than conventional static freeze dryers. This new process also makes it possible to reduce the energy consumption of freeze-drying. Met with Jean Delaveau, the founder of this company.

Jean Delaveau, founder of Lyophitech. Source: Lyophitech

An engineer by training, a graduate of AgroParisTech, Jean Delaveau has worked throughout his professional career in large groups such as Danone, Rhône-Poulenc and Sanofi. At Air Liquide, he used a static freeze-drying process to preserve lactic acid bacteria, but found the technology limited. He then waited until he retired to develop a new device and contacted LAGEPP (Laboratory of Automation and Process Engineering) to help him design it. A year later, at the end of 2017, and thanks to the financial support of Pulsalys, a SATT (Technology Transfer Acceleration Company), he was able to demonstrate the concept of a dynamic freeze dryer. Now, he is about to freeze-dry his first products for several manufacturers. Interview with Jean Delaveau, founder of Lyophitech.

Engineering Techniques: Describe the operation of conventional freeze dryers currently in service.

John Delaveau: They operate in static mode and consist of a large stainless steel cabinet where the products are placed in trays or in bottles. These are placed on hollow shelves inside which circulates a heat transfer fluid that initially allows the products to be frozen. Then, the second phase takes place, called sublimation, where the cabinet is placed under a vacuum, which causes the hot liquid to heat up. The water contained in the products in the form of ice then turns into steam and the product thus dehydrates at a very low temperature, between -20 and -30 degrees, while retaining its properties.

The disadvantage of this technology is that it is very slow to implement, between 2 and 4 days, and a lot of energy loss is observed. It also requires the presence of an operator who loads and unloads products on the shelves.

How did the idea for your new process come about?

It is based on a simple principle: if you stir a product (soups, rice, pasta) in a pot with a wooden spoon, you can heat it faster than if you leave it without. ‘y movement of heat. Agitation improves heat transfer and provides a more consistent temperature. The time saved is huge and the energy consumption is lower, because it is directed to the product, instead of to the walls to be heated.

How does your dynamic freeze dryer work?

The first stage of freezing the product is done separately using different equipment. Then, we designed a dynamic freeze-dryer consisting of a cylinder with the particularity of making a very slow pendulum movement. We fill it with frozen products, then close it to create a vacuum inside. A very small rotation of the cylinder improves the heat transfer and the vapor is more easily removed from the product then crosses one tube before being trapped in the second cylinder. Finally, this sublimation stage occurs between 4 and 5 times faster than that observed in static freeze dryers. Thus we are able to reduce energy consumption and lower the cost of freeze-drying between 20 and 40%.

The dynamic freeze dryer developed at the start. Source: Lyophitech

To reduce the working time required to feed this equipment, we are working on the design of a continuous loading system, thanks to the installation of baffles inside the cylinder. Eventually, we will be able to work in large quantities with products such as coffee, spices or red fruits, and thus we will be able to freeze-dry large volumes at an unbeatable price.

What stage of development is your project?

We protect our technology by filing patents in the main pharmaceutical manufacturing countries (Europe, United States, Japan, China, India, Canada…), because 80% of freeze dryers are sold in the pharmaceutical industry in these countries. On the other hand, it is a very complex industry in terms of its regulations and quality requirements. So we developed a strategy to gradually reach this market, starting first with the agri-food industry, then the cosmetics industry, then the probiotics industry and finally moved to the pharmaceutical sector.

We conducted feasibility tests in a pilot unit based on products entrusted to us by future customers and freeze-drying proved conclusive.

We won a competition organized by France Relance, and thanks to the financial resources we received, we are now building a shaping workshop in Vénissieux. From September 2022, we will receive a first dynamic freeze dryer, which we manufacture, with a capacity of 1,000 liters. It is able to freeze-dry 250 kg of products in 24 hours, and from autumn, we can deliver our first batches to the freeze-dry industry. We are currently signing contracts to process freeze-dried products such as bacteria as well as plant extracts for the nutraceutical, food and cosmetics sectors.

A number of dynamic freeze dryers with a capacity of 1,000 liters are gradually being delivered to us at our production unit and we aim to become a major player in processing.

Our factory will also serve as a showroom for future customers and from 2023, we will sell our first machines to manufacturers who will thus be able to freeze-dry their own products. We will also provide them with services to pass on our knowledge to them. Our ambition is to move quickly towards the international market.

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