The bioeconomy is a hot topic these days, right up at the top of policy agendas. It involves using renewable natural resources as a raw material. The circular bioeconomy introduces circularity into this concept: using what would otherwise be thrown away, using spent biological resources to regenerate ecosystems and minimising waste.

The ECESP website has a good selection of circular bioeconomy-themed content. This series will shine a spotlight on it.

Circular bioeconomy concept: slaughterhouse waste (bellygrass) and paper/pulp sludge as feedstocks for bio-based fertilisers and bioplastics

ELLIPSE: Efficient and novel reuse of organic waste streams

The ELLIPSE project seeks to optimise the use of two heterogeneous waste streams of which plentiful amounts are generated across Europe: slaughterhouse waste (bellygrass) and paper and pulp sludge. The project will produce cost-efficient polyhydroxyalkanoates (PHAs) for the agricultural and packaging sectors by co-processing these waste streams with other organic ones such as glycerol from the biodiesel industry and sludge from the dairy industry.

Integrating these waste streams as biorefinery feedstocks will reduce the volume of waste destined for landfill or anaerobic digestion. It will also open up new avenues for platform chemicals and bioplastics production, while creating additional revenue for the related industries generating the waste. The process has the added advantages of recycling water and decreasing soil degradation, groundwater pollution and methane emissions.

The selected ELLIPSE feedstocks are locally available and renewable, leading to nearly 100% renewably sourced personal care packaging and agricultural products. The ELLIPSE project will be able to cope with at least 100 tonnes of slaughterhouse waste and 20 tonnes of wastewater sludge derived from the pulp and paper industry. The ELLIPSE technology will have an impact on the European bio-economy by reusing 20 000 tonnes of rumen content waste and 50 000 tonnes of paper sludge each year.

The project's main goal:

• to convert two heterogeneous organic waste streams from the paper and slaughterhouse industries into high added value products in line with the waste hierarchy, specifically into PHAs suitable for personal care and agricultural applications.

Some of its specific objectives:

• Apply effective pre-treatments for heterogeneous paper and slaughterhouse waste
• Improve the yield of VFA production in acidogenic fermentation
• Obtain PHBV copolymers through efficient and sustainable processes
• Recover nutrients (nitrogen and phosphorous) to be used as bio-based fertilisers
• Demonstrate the environmental and socio-economic sustainability of new biobased compounds/products and guarantee the safety of the new circular bioprocesses.