1. Department of Chemical and Metallurgical Engineering, Tshwane University of Technology, Pretoria 0001, South Africa, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, South Africa, Department of Chemical Engineering, Nagoya University, Nagoya 464-8603, Japan, and Faculty of Engineering and the Built Environment, Tshwane University of Technology, Pretoria 0001-South Africa