The project
AgroVal - Sustainable valorisation of agro-industrial residues through integration of food, bioproducts and bio-energy production
Project coordinator: Prof. Irini Angelidaki (Technical University of Denmark)
Background & context
In the equatorial East African region (EA) including Tanzania, Kenya and Ethiopia, agriculture accounts for 80%, with coffee and sisal as the most important crops with 600 kiloton coffee and 100 kiloton sisal ropes produced annually. The related crop processing generates huge quantities of organic residues that form the bulk of waste products from Agro-processing in the region.
Coffee beans are harvested from fruits on coffee trees (Coffea arabica), which results in 99% of the organic load ending as wastes, including cherry skin (coffee husk) and leaves and 15 m3 of wastewater per ton coffee produced.
Sisal (Agave sisalana) is a species of flowering plants native to southern Mexico but widely cultivated in many other countries including the EA region. The fibres are produced from the leaves which accommodate 1000 fibres each and are currently used in rope and yarn production. The fibres are extracted by decortication where leaves are crushed, beaten and brushed away by a rotating wheel with blunt knives so that only fibre remain. Fibres are subsequently dried, brushed and machine combed. Unfortunately, production of fibres from sisal results in only 2% utilisation of the biomass as fibres. This process generates 100 m3 wastewater, 25 tons solid wastes and 60 tons stems per ton fibres produced.
The huge amounts of high organic load, containing wastewaters which are just disposed of in ponds, contaminating the underground. Moreover, the value of the product is relatively low and it could, with appropriate research, be upcycled to more valuable composite materials which could find more advanced applications and have a much higher price.
Objectives
Development of new platform technologies to strengthen circular bioeconomy and contribute to capacity building in East Africa. PhD and MSc students perform their research on agricultural residues valorization within a circular bioeconomy approach to convert them into high-value products and energy. Their sub-objectives are:
To establish mushroom production using coffee waste as medium.
To discover new enzymes excreted during mushroom cultivation on coffee waste.
To establish co-digestion schemes of the agroindustrial residues for enhanced biogas production
To produce high-performance biocomposites with Sisal yarn for use in the construction industry to substitute wood due to the higher stiffness and reduced moisture uptake.
To strengthen research capacity in utilization of waste and achievement of bioconversion technology for production of high value products towards a circular bioeconomy.
Project milestones
M1: Coffee and sisal waste processing mapped in East Africa
M2: The amounts and composition of wastewater / solid residue from coffee and sisal production determined
M3: Hydrophobization of sisal yarn established to increase the fibre hydrophobicity
M4: High performance composites produced, reinforced with sisal yarn and biopolymer superior to construction wood achieved
M5: Mushroom production achieved using solid residue from coffee
M6: Extraction of lignocellulose degrading enzymes achieved after mushroom cultivation
M7: Co-digestion of mushroom production residue and wastewater established
M8: Effective control of biodigestion in small scale biodigesters
M9: Sustainability model used on biogas processes of sisal and coffee waste
M10: Strategy for sustainable implementation of the concept achieved considering economic, social and environmental aspects
M11: Postgraduate Students’ midterm evaluation approved
M12: Strategy for research capacity strengthening established considering green transition beyond the project established