Oral
Abstract
Research summary supplied by the authors
During the production of leather, the structural protein of the hair - keratin - is produced as a significant by-product stream, which has hardly been utilised to date, but is disposed of in sewage treatment plants with energy expenditure or composted for a fee leading to an additional CO2-release. It has not yet been utilised as a material. Preliminary work has shown that tanning agents and fillers, which are necessary to achieve specific properties of leather (e.g., tensile strength, elasticity, softness) in the retanning process, can also be produced from proteins. In our recent work we processed hair by partial hydrolysis, modification and further chemical processing on a pilot scale to make it usable as retanning agent and filler for leather. A production plant in a container that had already been designed, constructed and built for other applications is used for this purpose. First results on calculation the product carbon footprint for the new re-tanning and filling material showed a potential reduction by two to four times compared to fossil-based agents. The new retanning and filling agent is expected to be able to partly replace the currently non-biogenic components in leather production with locally sourced biogenic raw materials. It contributes to better utilisation of the by-products of animal breeding. Utilising the hair is a further step towards making leather even more sustainable, with the potential to achieve this worldwide.