Microalgae have been accepted as a potential feedstock for biofuel production due to their high oil content and rapid biomass production. In this study, deoiled Scenedesmus obliquus (SO) was used for evaluating whether deoiled algal biomass residue is potential as an alternative energy resource for bio-ethanol production with different heterogeneous catalysts. The SO biomass was examined for its physiochemical properties and also evaluated using FTIR, XRD, and TGA techniques. The successful hydrolysis of SO was performed employing different eco-friendly bio-based heterogeneous catalysts and hydrolysate thus obtained was then subjected to fermentation using Saccharomyces cerevisiaeand was analyzed through HPLC and GC which resulted in the production of bio-ethanol with the highest yield of 68.32 % at 8.24 g/L concentration. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.