The main objective within the ReJuice project is to develop at least 3 feasible, sustainable and economically interesting value chains for the processing and reuse of the liquid fraction from green waste streams. Here, ReJuice refers not only to the reuse (Re) of juice streams from green waste streams (Juice), but also to the more efficient use of raw materials (Rejuice = Reduce). Within the project, the focus will be on finding high-quality innovative applications of green residue streams from the environmental service and agro-food sector that are common in both Flanders and the southern Netherlands (e.g. roadside grass, tomato stalks, leek waste, flower waste and duckweed). Therefore, this proposal is in line with the priority "Develop and strengthen research and innovation capacity and import of synthetic technologies" of the Interreg Vl-Nd programme.



So far, little attention has been paid to the liquid fraction from green waste streams, both in terms of its composition and potential applications. This project proposal therefore aims to close this knowledge gap by: 



- Determining the influence of various factors on the composition and stability of the liquid fraction, such as the type of green waste, collection moment, storage technique and duration, and pressing techniques used (WP3);

- To evaluate the potential of these streams as a source of molecules for obtaining high-quality bio-based products that contribute to more innovative green waste processing, including: as alternative local proteins, for growing microalgae, for producing bio-based and biodegradable polyhydroxyalkanoate (PHA) plastics, for fertilisers and biogas production (WP4).



As sub-objectives, ReJuice aims to:





Developing a green residue calendar to map in detail the availability, characteristics and application possibilities of at least 5 different green residue streams in the Netherlands and Flanders (WP5);
Optimising the refining process for green residue streams to test the separation of the liquid and fibre fractions from the streams (WP3);
Improving the logistics of the supply chain, including mapping suitable sites in Flanders and the Netherlands for green residue stream processing facilities and scaling up processes and equipment (up to TRL 7) to ensure they meet the identified needs, to yield a high-quality intermediate product for the proposed 5 types of end products (alternative proteins, microalgae, PHA plastics, fertilisers and biogas) (WP5); 
Characterisation of liquid and fibre fractions obtained from green waste streams, to ensure their technical and regulatory suitability for further processing into products and to search for bioactive molecules with high commercial value (WP3); 
Testing different fermentation techniques for creating value from liquid streams (microbial extraction, microbial conversion, anaerobic digestion). This should result in at least 3 robust value chains that will be further scaled up to TRL 5-6 (WP4);
Applying for an end-of-waste status for the most promising combination of green waste streams and products (WP6);
Mapping the potential of the different value chains through a hotspot analysis, TEA, and a market survey (WP6);   
Building a bridge between knowledge institutes, industry, government and citizens within and outside the consortium through 4 cocreation clusters in Flanders and the Netherlands, in which regional business cases with suppliers, processors and end-users will be elaborated and an advisory board to make the circular application of green waste streams in Flanders and the Netherlands catch on and roll out into scalable business cases (WP5 & WPCommunication).


This project application builds on the outcomes of innovative European research projects, including GrasGoed (VLA-NED), Grassification, (2Seas) and GoGRASS (Horizon2020). However, ReJuice goes a step further by looking at the valorisation of the total residual stream (fibre and juice fraction), and in this not only limiting itself to verge grass, but also analysing other common green residual streams from Flanders and the southern Netherlands. Important advantages of this are that an economically feasible process can be created that is less seasonal, and that this will identify the application and valorisation possibilities for different green residual streams to increase the impact of the project.