SURFOLY aims to demonstrate and promote an innovative circular business development model for the production of animal feed for small ruminants (sheep and goats) while supporting mixed crop-livestock systems and the olive industry in the Mediterranean area.
The new feed formula contains olive oil by-products (pomace, stone and polyphenols from wastewaters) utilised in an innovative way to improve product quality and reduce the life cycle environmental impact of the system (olive mill – feed manufacturer – farm). Pomace from olive mills is either centrifuged (three-phase process) or dryed (two-phase process). Olive stones and dried pomace are then pyrolyzed in a regenerative rotary kiln to obtain bio-char which is used to reduce the COD (Chemical Oxygen Demand) of olive mill wastewaters by absorbing polyphenols, hence reducing significantly the polluting impact of their use as a fertilizer or disposal. The polyphenols enriched char has antioxidant potential and can reduce methane emissions from ruminants – it is added to dried pomace to produce a nutrient mix which is subsequently pelletised and used as ingredient in the new formula for sheep and goats. Where small ruminants fed with the developed formula are allowed to graze in olive orchards, digested biochar is released back into the fields, improving carbon sequestration.
The project will produce experimental data, currently not available in the literature, on various aspects such as biochar quality, efficiency in the removal of polyphenols from wastewaters, the energy and economic sustainability of the pyrolysis process of solid mill residues. There is also potential for positive economic impacts from the uptake of the developed processes by farmers given the competitiveness of biochar production.
