1. School of Chemical and Metallurgical Engineering, Oil and Gas Production and Processing Research Unit, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein, Johannesburg 2001, South Africa
2. Department of Chemical Engineering, Thermodynamics, Materials and Separations Research Group (TMSRG), Mangosuthu University of Technology, Umlazi, Durban 4031, South Africa