Abstract—The extractive desulfurization of simulated fuel containing dibenzothiophene (DBT) and thiophene as sulfur compounds was carried out using SnCl 2 .2H 2 O – based Deep Eutectic Solvent (DES). High performance liquid chromatography (HPLC) was employed for the quantitative monitoring of the sulfur compounds in the fuel. The results showed that the DES exhibits higher desulfurization efficiency for DBT than thiophene. Optimum extraction conditions have it that, extraction efficiencies as high as 69.57% and 47.28% can be achieved with the solvent in a single stage for DBT and thiophene respectively. The work has not only shown that SnCl 2 .2H 2 O – based DESs can be used in desulfurization of liquid fuels but also proved their promising desulfurization ability in the presence of multi-component fuel. Index Terms—Desulfurization, extraction, deep eutectic solvnts, stannous chloride dehydrate. I. INTRODUCTION Crude oil, which is the major source of liquid fuels, naturally contains various kinds of sulfur containing compounds. Removal of these sulfur containing compounds in refining processes to below environmental set limits has drawn an increasing interest from both scientific and industrial communities. Generally, hydrodesulfurization (HDS) is the commercial technology used by most refiners for the removal of sulfur from fuels [1]. This technology is known to require high temperature, high pressure and catalytic operation, and inherent hydrogen consumption, thus making it more costly for deep desulfurization applications. However, HDS alone is not considered effective in removing refractive sulfur-containing compounds like dibenzothiophene (DBT) and its derivatives, especially 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) which is regarded as the least reactive sulfur-containing compound. Therefore, researchers ventured into the development of safer and yet economical techniques for desulfurizing liquid fuels to meet the environmental regulations [2], [3]. Among the proposed techniques, extractive desulfurization (EDS) has shown promising results toward the removal of refractive sulfur-containing compounds from liquid fuels. This technique can be carried out under mild operating conditions thereby leading to low energy Manuscript received August 12, 2014; revised January 5, 2015. This work was financially supported by The Research Council in Sultan Qaboos University, Muscat Oman under the project RC/ENG/PCED/12/02. The authors are with the Petroleum and Chemical Engineering Department, Sultan Qaboos University, 123, Sultanate of Oman (e-mail: zaharaddeenn@yahoo.com). consumption and without hydrogen consumption. Some research groups are of the opinion that if HDS is coupled with EDS, sulfur concentrations below the set environmental limit could be achieved [4], [5]. However, the success of EDS is basically governed by the choice of efficient and yet environmentally benign solvents. Most commonly used solvents in the petroleum industries like alcohols, amines, ethers and other volatile organic compounds are faced with challenges of either inefficiency in terms of extraction ability or negative impact on the environment. A class of solvent called ionic liquids (ILs) has been successfully employed in different extraction [6]-[8] and desulfurization processes including EDS [9]. Even though ILs have been found to be efficient in desulfurization of aromatic sulfur compounds at room temperature [4], [5], [10], their poor biodegradability, relative complex synthesis, toxicity and most importantly high cost limit their industrial application [11]. Another class of solvent called IL analogues, often referred to as deep eutectic solvents (DESs), has been developed and their applications in different research fields have recently drawn intensive interest in the research world. DESs are composed of a mixture of a salt and a hydrogen bond donor (HBD) or a complexing agent which results in a homogenous liquid medium with a freezing point lower than the freezing points of the constituent compounds [12]. The easier and simpler procedure involved in synthesizing DESs [13], the flexibility of selecting DES components such that they are biodegradable and nontoxic [14] and ultimately the cheaper components involved in making DESs all sum up together and make DESs more favorable than ILs in terms of their applications in different fields. Although DESs have been successfully applied in various fields [12], they have up till this moment very little application in the field of desulfurization of liquid fuels. Only recently Li et al studied the extraction desulfurization of model fuel with ammonium-based deep eutectic solvents [15]. Some more recent studies on the screening of DESs towards their application in desulfurization process were also carried out by our research group [13], [16]. Findings by both research groups showed that DESs can be promising in the field of desulfurization of liquid fuels. In continuation with our previous works [13], [16], this work investigates the novel application of SnCl 2 .2H 2 O-based DES for the extractive desulfurization of simulated fuel that contains thiophene and DBT as model refractory sulfur compounds. Zaharaddeen S. Gano, Farouq S. Mjalli, Talal Al-Wahaibi, and Yahya Al-Wahaibi International Journal of Chemical Engineering and Applications, Vol. 6, No. 5, October 2015 367 DOI: 10.7763/IJCEA.2015.V6.511 The Novel Application of Hydrated Metal Halide (SnCl 2 .2H 2 O) – Based Deep Eutectic Solvent for the Extractive Desulfurization of Liquid Fuels