Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel Full Length Article Synthesis of nano-Hap prepared through green route and its application in oxidative desulfurisation Biswajit Saha, Sandeep Kumar Yadav, Sonali Sengupta ⁎ Department of Chemical Engineering, Indian Institute of Technology Kharagpur 721302, India GRAPHICAL ABSTRACT Flower like structure of Ti-Mo impregnated nano Hap. ARTICLE INFO Keywords: Nano Hap Green synthesis Oxidation Thiophene LH model ABSTRACT Nano hydroxyapatite (Hap) was synthesized by green route using carrot peal extract and used as catalyst in thiophene oxidation reaction. The catalyst was characterized with TEM, XRD, XRF, SEM, BET and DLS size analysis. The particle size was found to be in the nano range. The highest conversion for thiophene oxidation was observed as 65%. Titanium and molybdenum were impregnated in nano Hap to investigate any further im- provement of its efficiency towards the oxidation and a substantial increase in conversion of thiophene, 82%, was observed after impregnation. The influence of different process parameters on oxidation of thiophene using Ti-Mo impregnated nano Hap as catalyst was investigated. The metal-impregnated catalyst was characterized with FTIR, SEM, XRD, EDS analysis before and after the reaction. Langmuir-Hinshelwood (LH) model was proposed to explain the kinetics of the reaction. 1. Introduction The present world needs the use of environmentally benign fuels with a specified low level of organo sulfur compounds [1,2]. Although hydrodesulfurization (HDS) [3–5] is the popular refining operation to remove sulfur compounds from fuel yet it requires high severity of operation under the flow of hydrogen [6–8]. Hence, to reformulate the process technology, catalytic oxidative desulfurization [9] can be chosen as one of the better choices among several other non conven- tional processes [10–13] which can operate at near ambient https://doi.org/10.1016/j.fuel.2018.02.139 Received 31 October 2017; Received in revised form 19 February 2018; Accepted 21 February 2018 ⁎ Corresponding author. E-mail address: sonalis.iitkgp@gmail.com (S. Sengupta). Fuel 222 (2018) 743–752 0016-2361/ © 2018 Elsevier Ltd. All rights reserved. T