Title: Bioethanol production by the utilisation of Moringa oleifera stem with sono-assisted acid/alkali hydrolysis approach

Authors: S. Sivarathnakumar; G. Baskar; R. Praveen Kumar; B. Bharathiraja

Addresses: Department of Biotechnology, Faculty of Bioengineering, Sathyabama University, Chennai, India; Department of Biotechnology, Arunai Engineering College, Tiruvannamalai, India ' Department of Biotechnology, St. Joseph's College of Engineering, Chennai, India ' Department of Biotechnology, Arunai Engineering College, Tiruvannamalai, India ' Department of Chemical Engineering, Vel Tech High Tech, Dr. Rangarajan and Dr. Sakunthala Rangarajan Engineering College, Chennai, India

Abstract: In this study, production of bioethanol was carried out by sono-assisted acid/alkali hydrolysis using the stem of Moringa oleifera. The woody stem was segregated and subjected to steam at reduce temperature for one hour residence time initially. Further acid and alkali treatment was carried out individually followed by combinations of acid and sonication, alkali and sonication. Sodium hydroxide, potassium hydroxide, hydrochloric acid, sulphuric acid and nitric acid were used with used with 3% (w/v) and 3% (v/v) concentration under temperature range of 60°C to 90°C for 60 min incubation time. Sonication under 60°C for 5 min and 40 kHz frequency was carried out. The increase in cellulose content and the decrease in lignin concentration were measured. The hydrolysate was further characterised using scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) to understand the changes in surface morphology and functional characteristics. The soft wood which when treated with sono assisted acid hydrolysis, the combination with nitric acid particularly at 70°C exhibited high amount of cellulose and low amount of lignin and no charring was found which was further taken for bioethanol production studies.

Keywords: Moringa oleifera; sonication; bioethanol production; biofuels; lignocellulosic material; LCM; woody stems; acid treatment; alkali treatment; cellulose content; lignin concentration.

DOI: 10.1504/IJESD.2016.079481

International Journal of Environment and Sustainable Development, 2016 Vol.15 No.4, pp.392 - 403

Received: 05 Jul 2015
Accepted: 17 Aug 2015

Published online: 28 Aug 2016 *

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