Novel sustainable metal complex based deep eutectic solvents for extractive desulphurisation of fuel

In this study, a series of metal complex DESs based choline chloride (MCDESs) with different metal chlorides including FeCl3, FeCl2, CuCl2, SnCl2 and ZnCl2 using 1,3-Diphenylg-uanidine and 1,5-Diphenylcarbazide as complexing agents were synthesized and their efficiencies for extractive desulphurisation were considered. FTIR technique was used for characterization of the synthetized MCDESs. The influential parameters including temperature, time, type of MCDESs, and the mass ratio of MCDESs to model fuel were investigated. Sn-diphenylcarbazide based choline chloride DES had the best potential for the extraction of dibenzothiophene, thiophene, and 3-methylthiophene from n-octane as model fuel. At optimum conditions of time 10 min, temperature 35 degrees C, and MCDESs to model fuel mass ratio 1:25 the highest desulphurisation (%) of 95.2 +/- 0.3, 94.5 +/- 0.5, 92.1 +/- 0.6 were achieved for dibenzothiophene, 3-methylthiophene, and thiophene respectively after one cycle of extraction which indicated high capability of the synthesized MCDESs for extractive desulphurisation through n-complexation. and pi-pi interaction with the target thiophenic compounds. Moreover, the used MCDES was successfully regenerated and efficiently reused in desulphurisation process which confirmed the industrial potential of the synthetized MCDESs. (C) 2020 Elsevier B.V. All rights reserved.