Using organic residual streams as an alternative feedstock is a concept which draws more and more attention these days. But the effective shift towards a workable value chain is still quite a challenge. VITO together with 8 Flemish entrepreneurs studied this challenge more closely, as part of co-creation programme. In one project the team looked into converting harvest waste into animal feeds. An other project dealt with locally mobilizing residual streams in a short value chain. Both projects combine the use of VITO’s expertise and infrastructure with the knowhow of the participating SME’s.
Turning harvest waste streams into animal nutritional supplements?
The participating entrepreneurs wanted to look into the valorisation of harvesting waste into animal feed, more specifically based on microbial fermentation. The challenge was to find out in what way a fermentation process would alter the composition of the stream, and if this would produce a more nutricious alternative. The coordinator of the project, Linsey Garcia-Gonzalez, who works as a researcher for VITO, studied the changes in composition of 3 fermented harvest waste streams, namely red onions, pears and sprouts. VITO’s research showed only a limited microbial conversion after fermentation. However, it turned out that specific bioactieve compounds were formed which have known nutricious effects. A possible next step can be to focus on the compositional change of complex fermented harvest waste streams and the optimization of the fermentation process itself.
More value from green waste
The second case focuses on the local mobilisation of residual waste in a short value chain. It is part of VITO’s expertise in developing new bio based value chains. Wet waste from mowing green banks is mostly composted. But, it is thinkable this kind of waste would be part of a more elevated value chain, which looks into extracting proteins and fibres. Bio refining is an option, but not techno-economic feasible for small amounts of this kind of waste, which is relatively highly contaminated. In a future project the group of entrepreneurs will study if local fermentation with micro-organisms will lead to a product that can be used as a soil improvement product, and as such can provide an alternative for composting.