The important European research project LIFE GOAST – Green Organic Agents for Sustainable Tanneries (LIFE16 ENV/IT/000416), led by GSC Group, is about to begin. Researchers, who started in July 2017, set themselves the goal of demonstrating the effectiveness and benefits, on an industrial scale, of a new tanning technology for the production of items in the automotive, furniture and footwear sectors, acting as a more sustainable alternative to the traditional chrome tanning process.
“The ultimate goal is to demonstrate the reduction of the environmental impact of the new process, with the ultimate goal of obtaining a leather product of comparable or better quality, while at the same time reducing problems related to waste disposal”, explains GSC Group.
Alongside the Venetian company that specialises in the development and production of chemical tanning auxiliaries, the partners involved in the European project are: Conceria Pasubio, as an expert in leather processing; Medio Chiampo Spa as the management company of the Integrated Water Service including the treatment of industrial wastewater, and finally, the Cà Foscari University of Venice as scientific support.
New tanning agents
As also reported in the article published in the magazine “Chemistry and Industry” (n° 3/2020), the GOAST technology, developed as part of the project, is based on the combination of special functionalised acrylic polymers and synthetic tannins. The functionalisation of these polymers is fundamental to allow to increase the interaction with collagen through covalent bonds, thus obtaining a skin with remarkable physical-chemical properties. Experts of GSC explain that, for the production of these polymers, an appropriate synthetic protocol has been developed at laboratory level which has made it possible to obtain consistent results in the tests carried out. “The scale-up of this protocol, which is still being implemented, has made it possible to obtain quite satisfactory results”. The technology is currently under patent examination (patent pending).
Perfect leathers for the automotive sector
The hides treated with the LIFE GOAST system are white-yellowish in colour with a shrinkage temperature between 70° C and 75° C. It is important to highlight that they were easily shaved to a thickness of 1.0 to 1.2 mm, ideal for the subsequent retanning phase.
The results obtained from the characterisations have made it possible to highlight that these leathers have appropriate features for their use in the automotive sector.
The technical feasibility of the LIFE GOAST implementation and its social and economic impact will be analysed through the Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methodology with a “gate to gate” approach that aims to demonstrate the sustainability of the chain production, from the arrival of raw leather in the tannery to its processing up to the semi-finished leather phase (crust).
Redevelopment of waste
In compliance with EU directives, for which the treatment of waste is fundamental to guarantee a low risk level and a high level of environmental protection, the LIFE GOAST project proposes, as an additional objective, the characterisation and requalification of a solid waste (shaving powder) coming from one of the processing stages.
In particular, the attention is focused on the production of biochar through the pyrolysis approach and its application as an absorbent material, reinforcing agent and potential soil improver.
According to the researchers, LIFE GOAST technology has potentially proved to be a valid alternative to the traditional chrome-based tanning process, whose optimisation can certainly lead to a tanning process with less environmental impact. Despite the different chemical nature of the tanning agent, LIFE GOAST technology can be applied following the standard procedure of chromium tanning as a starting point, by replacing chromium salts, and adapting it to the new molecule. The greasing and retanning agents used are also the same as those in the traditional chromium process.
The leather produced with LIFE GOAST technology has shown characteristics suitable for the application in the automotive sector which, notoriously, requires very high performance standards when compared to other sectors such as clothing or furniture.
Since LIFE GOAST technology does not include the use of chromium and other metals in the tanning process, it has a potentially less environmental impact, especially with reference to the treatment of waste and the related disposal of sewage sludge, but also for the treatment of solid waste. In this context, the pyrolysis heat treatment of LIFE GOAST shaving powder produced particularly advantageous results as it does not require pre and/or post biomass treatment for the elimination of chromium. Pyrolysis has brought to obtain of a biochar free of dangerous metals and with promising characteristics for its application as an absorbent material and potential soil conditioner.