Bananas represent 33% of the total agricultural production of the Canary Islands, with an annual turnover of 280 million. The Canary Islands account for 52% of total European banana production (the other main producers for Europe being the French overseas territories in the Americas). Each year 400m kg of bananas are produced, with 9 000 ha under cultivation, creating employment for over 27 000 people, both directly and indirectly. The downside of banana production is that it generates organic waste (pseudostem) that is usually left on the plantation once the fruit has been harvested. Since this has no nutritional value for the soil its accumulation poses a problem for future harvests and may have negative impacts on the environment. It generates various microorganisms that can affect other crops since clogged streams can accumulate water and result in fungi growth. While various studies demonstrate the significant benefits of banana plant waste due to its high content of fibres and compounds such as antioxidants, its full potential has not been realised.
The project LIFE BAQUA aimed to optimise the use of an organic waste product that is usually landfilled: the waste from banana crops (pseudostem). The project planned to create green business opportunities by valorising this waste into products with market value, contributing to the goals of the EUs 7th Environment Action Programme of the creation of a resource-efficient, green and competitive low-carbon economy.
Specifically, the project planned to extract the wastes natural fibres and use them as natural additives to reinforce 100% bio-based and 92-98% biodegradable plastics. In particular, the project would produce prototypes for biodegradable fish feed bags, biodegradable covers to protect banana trees against UV radiation and plastic components for different devices and household appliances. The project also planned to use a by-product of the fibre extraction process, pulp. Banana crops have a high antioxidant content and the pulp would be used in the manufacture of fish feed. Currently, synthetic substances are added as antioxidants to fish feed to improve the life of the final product. These actions would reduce waste during harvesting and final consumption, thereby eliminating the need for waste transportation and its related cost.
The LIFE BAQUA project demonstrated the viability of a new circular economy process of obtaining fibre and pulp from the waste (pseudostems) from banana plantations. It developed and optimised a fibre extraction pilot plant that produces clean, high-quality fibre at a high production rate. The obtained fibre was included in a bio-based matrix for the production of biodegradable bags to contain fish feed and also banana sleeves for banana production in a full circular chain. This fibre was also used to reinforce a conventional plastic matrix for a range of plastic products. The pulp obtained from the extraction process was also utilised. It was included in nutrient-rich feed for the fish species tilapia and seabass, containing up to 6% pulp. Pulp from banana pseudostem can therefore be considered a new alternative raw material, increasing the aquaculture sector's sustainability. However, the low level of antioxidants in banana pulp led the project to focus on another waste from banana production: the flower that is left over from a banana bunch. This waste has demonstrated a good antioxidant potential, increasing the resistance of fish to several health threats.
A Life Cycle Assessment and the Life Cycle Cost analysis showed that BAQUA plastic products have higher impacts than conventional ones due to the additional processes needed. However, these impacts are more than compensated for by the reduction of agricultural waste and the substitution of corn by banana waste products in animal feed. Overall, the project extracted 44 tonnes of agro-waste in the form of banana pseudostems and flowers from the farms, avoiding 150 kg of N2O emissions during the project lifetime. The substitution of polymers by bioplastics and banana fibre has avoided 306 kg/year of CO2. The project also prepared an industrialisation plan to upscale the extractive process on the Canary Islands, where banana production is one of the most important economic sectors. A clear strategy for its implementation was presented to the regional authorities, which have shown great interest in upscaling the project. The project team calculated that on an industrial scale a business would avoid 341 tonnes/year of N2O emissions and up to 8 220 tonnes/year of CO2. Furthermore, LIFE BAQUA became a reference point for circular economy in the Canary Islands and contributed to Spanish national strategy on circular economy.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).