[1] Covenant Univ, Coll Engn, Dept Chem Engn, Ota, Nigeria
[2] Tshwane Univ Technol, Dept Chem Met & Mat Engn, Private Bag X680, ZA-0001 Pretoria, South Africa
[3] Univ Pretoria, Fac Engn Built Environm & Informat Technol, Dept Chem Engn, Private bag X20, ZA-0028 Pretoria, South Africa