Distribution and selectivity of Thiophene in ternary mixtures of {n-octane/n-hexadecane + Thiophene + acetonitrile / DMF} at 308.15K and atmospheric pressure

Abstract

• LLE measurements for removal of thiophenic sulphur are presented. • Solvent include DMF and acetonitrile. • Type i LLE behaviour was observe. • DMF found to be slightly more selective to thiophene. The removal of thiophenic sulphur constitutes ongoing research into the desulphurisation of fuels to comply with emission requirements and cleaner production. For the determination of effective solvents, this work considered and compared acetonitrile and N,N-Dimethylformamide (DMF) in the separation of thiophene from model fuels, which in this case was characterised by using n-octane and n-hexadecane. Ternary liquid-liquid equilibria (LLE) data were measured for four ternary systems, namely, {n-octane/n-hexadecane + thiophene + acetonitrile/DMF} at 308.15 K and atmospheric pressure. The NRTL equation was applied in the thermodynamic modelling, and consistency checks were executed using the maximum likelihood method on Aspen Plus® Version 12. The measured data was consistent with the calculated binary interactions with an average root mean square deviation (RMSD) of 0.001 and showed that all systems portrayed type I LLE behaviour. It was observed that DMF presents improved distribution ratios and selectivities to thiophene from the model fuels n-octane and n-hexadecane compared to acetonitrile.