Chemical and thermal characterization of potato peel waste and its fermentation residue as potential resources for biofuel and bioproducts production

Abstract

The growing demand for renewable fuels has driven the interest in the utilization of alternative waste materials such as potato peel waste (PPW) which contains fermentable carbohydrate. Fermentation of PPW using a mixed microbial consortium yielded about 60% unreacted PPW fermentation residue (PPW-FR). The PPW and PPW-FR were characterized by a combination of Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies, gas chromatography-mass spectrometry (GC-MS), and thermogravimetric analysis (TGA) to quantify changes after fermentation. Fermentation of PPW resulted in fermentation of starch and concentrating lignin plus suberin and lipids in PPW-FR. TGA analysis showed that decomposition peaks differed for PPW (423 °C) and PPW-FR (457 °C). Pyrolysis-GC/MS showed an increase in phenolic and long chain fatty acid compounds with a concomitant decrease in carbohydrate derived compounds in the PPW after fermentation. Both the PPW and PPW-FR have shown potential based on properties to be converted into crude biofuel via thermochemical processes.

Keywords: chemical analysis; fermentation residue; potato peel waste; thermo gravimetric analysis.