Carbonisation of chrome waste: sustainable energy, cost-effectiveness and recycling

The leather industry is currently under severe threat from efforts to eliminate environmental pollution issues caused by the generation of leather waste. Landfills must be used to dispose of leather waste, which harms the environment. Use of different chemicals during leather processing produces wastes in solid, liquid and gaseous forms, contributing to environmental pollution. The development of leather/paper-waste-based materials is a solution promoted by the recycled leather industry. A study was conducted in this work to prepare a polymerised electrolytic solution (PES) from chrome-containing leather waste using carbonised particles, microfibrillated cellulose and poly(ethylene glycol) to investigate their potential use in sustainable energy production. In this method, the consumed power (rechargeable) is based on the redox process. Field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were used to investigate the physical and chemical features of the PES. On the PES, energy generation was demonstrated using a multimeter and rheological properties. The results show that energy was produced with a voltage of 1101.12 ± 1.00 mV per cell, a current of 639.12 ± 0.42 mA per cell and a resistance of 88.77 ± 0.17  Ω per cell. Rheological tests were conducted at 25°C with 8% (w/v) PES and gradually increased shear-strain rates of 0.01–100 s⁻¹. This work presents the environmental results of a comparative examination of solutions for material and energy recovery from waste, along with those derived from mass and energy balances.