Sustainability and energy transition are currently very much in the spotlight. An important aspect of this is the protein transition. The Netherlands currently imports large quantities of proteins, especially soy. One of the goals is to become more self-sufficient in the field of proteins. We now largely depend on soy imports for concentrates, the protein-rich part of animal feed. We can replace this by extracting proteins from duckweed, for both human and animal nutrition. The green duckweed, which we often find in ponds and standing water, is very high in protein and offers opportunities for large-scale commercial exploitation. An additional advantage is that it makes it possible to restore the nutrient cycle. The often mentioned manure surplus mainly arises from imports of animal feed containing nutrients (currently mainly soy).
Previous projects
Previous duckweed projects have been unsuccessful. The ponds were too too expensive and too small to be commercially successful. The current business case for animal feed is also difficult because the value of animal food quite low is which results that soy meal is often used, the by-product released during the production of soybean oil.
That is why we are now looking at the production of high-quality ingredients for human foods at CCS. Duckweed is still at the beginning of crop breeding. There is still much to be gained, as has happened with the other agricultural crops in the past. It is expected that in crop breeding, the yields per hectare will increase and the cultivation costs will decrease. The use of duckweed as animal feed therefore seems imminent.
With a duckweed pond, the yield per hectare in the Netherlands can be five to ten times higher than with soy cultivation at comparable protein levels. In short, duckweed is an ideal crop for the protein transition. When duckweed is used for food, the yield can even rise to tens of thousands of euros per hectare.
Photo of the first duckweed pond constructed by CCS
Challenges
What is holding us back? There are two main inhibitory factors. First, recognition is needed from the European Union for the use of duckweed as food. This has been requested by our partner ABC Kroos from Raalte and is expected to be completed in the course of next year.
The second inhibitory factor consists of the large investments that are required. The investments for the construction of ponds and other facilities can amount to hundreds of thousands of euros per hectare. A covering of the ponds is desirable for a high yield per hectare. As a result, CO2 fertilization can take place and a lot of energy can be saved. Moreover, a challenge is to optimally fit this into the landscape. The CO2 can be obtained from the manure fermentation, which also closes this cycle better. By combining innovative things in this way, the large investments can be recouped within a few years.
In short: there are still plenty of challenges. CCS is happy to meet these challenges and has already built a first test pond and the construction of a second pond will follow soon. In this way, we are working on the protein transition to make the Dutch agriculture even more sustainable.
About this article
6 November 2019 / Author: Dr. Ir. René Cornelissen
