Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel Full Length Article Adsorptive removal of dibenzothiophene from diesel fuel using microwave synthesized carbon nanomaterials Divyam Jha a , N.M. Mubarak b, ⁎ , Mohd. Belal Haider a , Rakesh Kumar a , M.S. Balathanigaimani a, ⁎ , J.N. Sahu c,d, ⁎ a Department of Chemical Engineering, Rajiv Gandhi Institute of Petroleum Technology, Jais 229304, Uttar Pradesh, India b Department of Chemical Engineering, Faculty of Engineering and Science, Curtin University, 98009 Sarawak, Malaysia c University of Stuttgart, Institute of Chemical Technology, Faculty of Chemistry, D-70550 Stuttgart, Germany d South Ural State University, Chelyabinsk, Russia GRAPHICAL ABSTRACT M-CNT M-CNF DBT Preparation of Adsorbents Adsorptive Desulfurization ARTICLE INFO Keywords: Dibenzothiophene Microwave synthesized carbon nanotube Microwave synthesized carbon nanofiber Desulfurization Adsorption ABSTRACT Microwave synthesized carbon nanotube (M-CNT), and carbon nanofiber (M-CNF) were tested for removal of dibenzothiophene (DBT) from a model diesel fuel (MDF) by adsorption process. M-CNT showed relatively higher DBT removal capacity over M-CNF. The maximum DBT adsorption by M-CNT and M-CNF were 43% and 35%, respectively, for an adsorption condition of 0.25 g of adsorbent, 250 mg/l of DBT in MDF, 30 °C, 60 min and 250 rpm. The Sips and Freundlich adsorption isotherm models were used to correlate the adsorption equilibrium experimental results of DBT on M-CNT and M-CNF. The negative values of ΔG°, ΔH°, and ΔS° from the ther- modynamic studies confirm the spontaneity and feasibility of the system, exothermic nature and non-random behavior of DBT molecule on M-CNT respectively. The adsorption kinetic results show that the adsorption systems of DBT-M-CNT and DBT-M-CNF obey the pseudo-second order and pseudo-first order kinetic model, respectively. Further it was also found that the surface diffusion is the rate controlling step for DBT adsorption on both M-CNT and M-CNF. 1. Introduction The sulfur compounds separation from liquid fuel is getting more and more attention of petroleum refineries and researchers as the combustion of these compounds affects the environment as well as human health by emitting SOx [1,2]. Various stringent norms have https://doi.org/10.1016/j.fuel.2019.01.006 Received 31 August 2018; Received in revised form 6 December 2018; Accepted 1 January 2019 ⁎ Corresponding authors. E-mail addresses: mubarak.mujawar@curtin.edu.my, mubarak.yaseen@gmail.com (N.M. Mubarak), msbala@rgipt.ac.in (M.S. Balathanigaimani), jay_sahu@yahoo.co.in (J.N. Sahu). Fuel 244 (2019) 132–139 0016-2361/ © 2019 Elsevier Ltd. All rights reserved. T