PROJECT DESCRIPTION
BACKGROUND
The EU tanning industry has a turnover of €48 billion, employing around 435 000 people. Italy has a 65% share of the European market, accounting for the annual processing of 6.5 million tonnes of hides and the finishing of 125 million m2 of leather. Currently, over 85% of the leather produced worldwide is tanned with Cr(III) salts owing to its low cost, versatility of use and high quality of finished products. However, Cr(III) can oxidise to Cr(VI), which is highly toxic and carcinogenic, both in finished leather and in wastewater. But leather tanned using chrome-free alternatives, such as synthetic tanning process (STP) and aldehyde tanning, has physical and mechanical characteristics that are significantly inferior. Furthermore, they do not solve health and environmental issues of chrome tanning, since formaldehyde (carcinogen) and phenol (cytotoxic) can be released during the process. A similar problem emerges with the natural tannin processes (NTP), which generate high chemical load in wastewater in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD), due to the presence of non-tanning low molecular weight substances (LMWS).
OBJECTIVES
The LIFE I’M-TAN project aims to validate on a semi-industrial scale (TRL8) the use of highly sustainable innovative chemically modified natural tannins (CMNT) for environmentally sustainable high-quality leather for footwear, handbags and leather goods. The process will have low chemical hazard, sustainable costs, reduced waste and improved circularity (recycle/re-use of waste) compared to the conventional process, STP and NTP. An innovative purification process will allow to separate Concentrated Purified Natural Tannins (CPNT) from non-tanning Substances (LMWS), starting from the most commonly used chestnut and quebracho extracts. The CPNT will then be chemically modified according to green chemistry principles (bio-based chemicals, zero-waste) to produce the final tanning agent.
Specifically, the project aims to:
- Reduce hazardous chemicals, such as chrome salts, aldehydes and phenols, in tanning agents;
- Reduce the COD/BOD in tannery effluents (compared to STP/NTP);
- Reduce water consumption in leather tanning by recovery/recycling wastewater;
- Recover/recycle CMNT leather scraps to produce fertilisers and LMWS to produce additives for animal feed;
- Replicate the LIFE I’M-TAN process in other tanneries in Italy and the EU, drawing up a business plan for the market introduction of new products/processes;
- Analyse the impact of the innovative process through LCA/LCC, social LCA (sLCA), with EPD, PEF and Ecolabel certification (possibly achieved soon after project end) to demonstrate the sustainability of the production chain from CPNT extraction to leather production and wastewater treatment; and
- Draw up proposals for BAT/BREF updates based on results of the LCA/EPD/PEF.
The project will contribute to the implementation of a wide range of EU policy:
- The Industrial Emission Directive IED by reducing potential release of hazardous substances in tanning processes;
- The REACH regulation, by fostering the reduction of usage of hazardous chemicals and for the possible upcoming registration of polymers under REACH (Commission proposal for 2022);
- The Water Framework Directive, by reducing water consumption in tanning processes and pollutant charges in related wastewaters, and by developing solutions for improved recycling and re-use of waste streams from tanning processes;
- Regulation on animal by-products, by developing solutions for recycling of tanning shavings; and
- The EU BAT/BREF for the tanning of hides and skins, by providing data for possible future updates.
RESULTS
Expected results:
- Elimination of chrome salts (90 kg/t), mineral acids (20 kg/t) and sodium chloride (80kg/t) in comparison with conventional processes;
- Elimination of leather scraps containing chrome (70 kg/t) in comparison with conventional processes;
- Elimination of aldehydes (50 kg/t) and phenols (70 kg/t) with respect to STP;
- 25% reduction of natural tannins required (250 kg/t);
- 30% recycling of tanning water bath (0.6 m3/t), reducing water consumption by 60%;
- 25% reduction of COD/BOD in wastewater compared to STP/NTP;
- 80% recovery/recycle of LMWS for animal feed (200kg/t of CPNT produced); and
- 20% recovery/recycle of CMNT leather scraps for fertilisers (15 kg/t).
