F-Cubed & Life-CompOlive: Towards a Circular Olive Industry
Traditionally, olive groves consist of no more than 200 trees per hectare, however, modern high-density or super high-density plantations with irrigation systems and mechanised pruning, harvesting and biomass collection can have up to 2000 trees per hectare. The conversion of traditional groves into modern plantations is proceeding at a rate of 1.5% per year and the majority of new olive groves are adopting the high-density model.
The modern, mechanised systems are obviously more productive and profitable but necessarily also produce large amounts of biomass. Traditionally, pruning residues have been burnt to reduce the risk of the transmission of pests and disease or mitigate the risk of accidental fires. A more recent and increasingly common practice is to chop-up the residues and use them as mulch to improve soil function.
Although studies did show improvements in the levels of soil organic carbon and water conservation, the results varied considerably depending on the moisture content of the residues and when, how much and where they were distributed. This has raised doubts over the efficiency and effectiveness of the practice over the long term.
Similar difficulties and concerns have been expressed over the use of olive pomace for composting. The humidity and high concentrations of polyphenols, lipids and organic acids in the pomace means that it can cause soil and water pollution if not properly dried and mixed with other organic matter.
European projects like Go Oliva, SustainOlive and ARTOLIO and trying to tackle some of these issues by implementing sustainable management solutions to address soil erosion, biodiversity loss, water usage and the use of olive grove biomass for fertilisation and composting.
Whilst these projects are addressing sustainability and circularity issues primarily within the olive manufacturing sector, F-CUBED and the Life-CompOlive project aim to valorise the residues for the benefit of the European circular economy as a whole as well as creating an extra revenue source for the olive farmers. Through hydrothermal treatment, F-CUBED extracts oil and nutrients and converts the effluent into biogas and intermediate bioenergy carriers, all of which can be utilised across a range of industrial sectors. Life-CompOlive valorises the pruning residues by creating wood-based fibres and bio-composites which can be used for furniture manufacturing and automobile interiors and reduces the use of fossil fuel based virgin plastics.
Furthermore, projects such as OLEAF4VALUE aim to valorise the olive leaves via the extraction of bioproducts for use in the food, feed, performance chemicals, cosmetics, nutraceuticals, and pharmaceutical industries. PHENOLIVA intends to extract anti-oxidants from the olive pomace for use in the food industry and Go Oliva, in addition to implementing composting processes for the pomace, are aiming to valorise the olive stone by combining it with bioplastics to create a new material called Oliplast which can be utilised in the production of products, components and packaging across a range of industries.
The combination of all these projects, along with improvements in olive oil extraction processes, have the potential to greatly enhance the sustainability, circularity and profitability of the olive sector. This is why F-CUBED and Life-CompOlive have setup the The Olive Circular Economy Network with the objective of engaging a range of projects in joint communication and dissemination activities, knowledge sharing and exploring the potential of process integration to improve efficiency and increase the possibility of commercialisation.
It is understood that the needs of the olive industry will vary across individual farms and associations, regions and timeframes and that is why the establishment of networks and collaboration between projects with a diverse range of technologies, processes and objectives, but with a similar overall goal, is so important.
The establishment of olive residue processing plants with a diverse but complimentary range of technologies, processes and products could adapt to the specific needs of individual farms and olive grower associations, whether this be the production of compost or mulch for internal use or bio-composites and pellets to be sold for use in industry. The flexibility and diversification of the olive industry´s use of biomass and the potential additional revenues through the creation of new products and services can only be a benefit to the sector and the EU circular economy as a whole.
Concurrently, this will provide olive mill workers with additional skills and new opportunities of employment for people in the region. It will focus on the needs of the olive growers and direct the use of the technologies towards the benefit of the farmers rather than the farmers having to adapt to the new technologies. It will create a more sustainable, circular industry which is resilient and adaptable to economic, social and environmental changes. These aspects align themselves perfectly with the European Commission´s Industry 5.0 policy, placing sustainable, human-centric and resilient industrial practices at the heart of the EU´s transition to a green, circular economy.
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