Valorization of Leather Industry Solid Waste for Sustainability Through a Biorefinery Approach

The leather industry generates $150 billion USD annually. The industry that processes animal hides or skins for finished leather goods generates a lot more solid waste than its main output, leather. The current ineffective disposal of these solid wastes (via open dumping, incineration, and landfilling) results in pollution, which obstructs the industry’s path to sustainable expansion. Interestingly, recycling waste into usable form seems like a potential option. Leather biomass contains collagen, keratin, and fat and can be used to produce sustainable bioproducts and replace petroleum-based materials. This chapter provides an extensive perspective on the effective reutilization of diverse forms of leather waste (keratin waste, untanned/fleshing waste, chrome-tanned waste, and tannery waste sludge) that are generated at various stages of processing the leather. However, there is still a sizable difference between the stated targets for sustainable leather technology and the levels that have been reached, despite ongoing research efforts. The chapter concludes that solid waste, which is generated from the tannery industry, is a gold mine that can be immediately used to make money while closing the loop.