Good practice:

COCONAT: Innovative production processes of tanning agents and dyes from agri-food waste materials

The project offers an integrated solution for the valorisation of agri-food waste and the reduction of the environmental impact of the tanning industry providing thus an example of industrial symbiosis.
The polyphenols extracted from the processing residues of food products can be used as natural dyes and tanning agents in the leather processing industry, thus making agri-food waste a resource from which to obtain raw materials, rather than a waste destined for disposal. Furthermore, the proposed solution promotes synergies between key industrial sectors (i.e. agriculture, food processing, tanning industry), maximizing the value of agricultural and food sector waste and increasing the competitiveness of companies in the tanning sector by strengthening and differentiating the leather market through the offer of hypoallergenic and eco-sustainable products.
The products developed will replace materials such as chromium, zirconium, aluminium, aldehydes and other tanning agents traditionally used, as well as azo and metal-complex dyes, and allow the production of biodegradable and hypoallergenic (metal-free) articles with product characteristics and performance in line with the production standards of the companies.
COCONAT grant several benefit in terms of fostering circular economy, such as agri-food recycling, reduction of use of hazardous substances in the leather and tanning sector and development of environmental friendly product, suiting cohesion funds environmental prio

Total cost: 2.44 million euro
Public funding: 1.15 million euro of Tuscany ERDF OP 2014 - 2020
Five SME, one R&D private centre and one university are involved as funding beneficiaries and thus project developers.

Tanning agents and dyes extracted from 100 Kg of walnut husk and chestnut peels waste were tested, resulting in over 10 square feet of leather ready for the market. Such agents provide a concrete example of industrial symbiosis, fostering innovation in agri-food waste recycling and reducing environmental impacts of leather and tanning industry by substituting traditional hazardous substances containing tanning and dyeing agents.

The collection in the Tuscany region of waste materials suitable for the innovative extraction processes in significant quantities to be used on an industrial level has been and is rather difficult.

The technical objectives achieved with the project are:
- the identification of waste matrices from which polyphenols can be extracted to be used as dyes and tanning agents;
- the development of extraction processes of new natural products for the tanning industry and their validation on a pilot scale;
- the pre-commercial validation of the products developed in the leather processing cycle;
- the evaluation of the actual environmental sustainability of the proposed waste recovery processes.