[1] North West Univ, Fac Engn, HySA Infrastruct Ctr Competence, ZA-2520 Potchefstroom, South Africa
[2] North West Univ, Fac Engn, Sch Chem & Minerals Engn, ZA-2531 Mmabatho, South Africa
[3] Univ Stellenbosch, Dept Proc Engn, ZA-7602 Matieland, South Africa