One for Two: Conversion of Waste Chicken Feathers to Carbon Microspheres and (NH₄)HCO₃

Abstract

Pyrolysis of 1 g of waste chicken feathers (quills and barbs) in supercritical carbon dioxide (sc-CO₂) system at 600 °C for 3 h leads to the formation of 0.25 g well-shaped carbon microspheres with diameters of 1–5 μm and 0.26 g ammonium bicarbonate ((NH₄)­HCO₃). The products were characterized by powder X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Raman spectroscopic, FT-IR spectrum, X-ray electron spectroscopy (XPS), and N₂ adsorption/desorption measurements. The obtained carbon microspheres displayed great superhydrophobicity as fabric coatings materials, with the water contact angle of up to 165.2 ± 2.5°. The strategy is simple, efficient, does not require any toxic chemicals or catalysts, and generates two valuable materials at the same time. Moreover, other nitrogen-containing materials (such as nylon and amino acids) can also be converted to carbon microspheres and (NH₄)­HCO₃ in the sc-CO₂ system. This provides a simple strategy to extract the nitrogen content from natural and man-made waste materials and generate (NH₄)­HCO₃ as fertilizer