A Raman spectroscopic study of the pyrolysis of lactose and tannins

Lactose and tannin are eco-friendly alternatives to commonly used binders for carbon-bonded alumina filters that are applied in steel melt filtration. The investigation of binder pyrolysis is a contribution to understand the production process of these filters. In this work, lactose and the tannins gallic acid, ellagic acid, and tannic acid were investigated by Raman spectroscopy. The tannins were measured in situ in an argon-filled heating chamber. The transformation of the tannin molecules to a system of amorphous disordered carbon could be observed in the Raman spectra. In addition, the condensed pyrolysis products of the tannins were measured and identified. The Raman spectra were supported by peak positions calculated with density functional theory.