Searious and CirTec crawl into the skin of a fish!

11 March 2022

New technology turns byproduct from fish processing into high-value product

When you think of fish you do not automatically make a link with leather. Yet the skin of salmon, cod or haddock, for example, is an excellent raw material for sustainably producing exotic leather with the structure of a water snake. Searious BV from Beetgumermolen (municipality of Waadhoeke) has developed a technology to produce leather without chromium, brine and fungicides. CirTec from Purmerend supplies a core component in water treatment so that the unique production process becomes a closed system. Both parties will sign an agreement at the Aqua Netherlands trade show to ratify the cooperation.

Leather made from fish skin is not new, or indeed, it has been around as long as man has been eating fish. Even in our present day, fish leather is increasingly being produced, as the main raw material is an upcycled material from a by-product of fish processing. However, if harmful substances such as chromium, brine and fungicides, among others, are used in the tanning of leather, then a significant part of its supposed sustainability is lost. That sustainability aspect moved Folkert Fennema of Searious to develop a sustainable tanning process, without waste. Ever since 2016, Fennema has been the driving force behind the development, a period during which he has collaborated with several parties.

The final challenge in sustainable fish leather tanning is the treatment of a liquid stream that still contains too much water to be put back into useful use. That’s where CirTec comes in. Using low-grade energy to evaporate water creates a reusable concentrated resource-rich stream with positive value. The sum of technology results in a sustainable tanning process, converting a residual stream into a high-value product without creating a waste stream. A development fully in line with Europe’s circularity goals.

Developing a beautiful product that is sustainable and innovative is one thing, but if the cost proves too high it is doomed to failure. The tanning of fish hides using the Searious method is both technically and financially feasible and thus combined with circularity and environmental benefit a major step forward.

At its Leeuwarden location, Searious will build a prototype plant this year with all process steps integrated at a representative scale. The project started in late 2021 and will be completed in mid-2023. Following this, the final installation will be realized.

The relationship of Searious and CirTec is purely related to the water section and so the AquaNederland trade fair and more specifically in the Aqua Business Lounge was chosen for the official ratification of the cooperation. CirTec is a participant in the fair and can be found at booth number L.108.

For more information, please contact:
CirTec B.V. – Coos Wessels
T: +31 (0)299 – 79 20 80


Searious BV – Folkert Fennema
T: +31 (0)6 – 2552288
W :