Prof. Thokozani Majozi
School of Chemical and Metallurgical Engineering,
University of the Witwatersrand, Johannesburg, South Africa
Title: On Mathematical Optimization Methods for Consideration of Water-Energy Nexus in Synthesis of Chemical Plants
Abstract
The lecture presents recent developments in the exploration of water-energy nexus as it pertains to both batch and continuous processes. In particular, the application of advanced mathematical modelling as an optimization tool is demonstrated through real-life case studies and practical results. The systematic mathematical framework is based on a comprehensive superstructure for an integrated membrane network with a background network of water using operations. The water-energy nexus character of such a system emanates from the fact that the integrated membrane network is an energy sink, whilst the background water using process is a water sink. Increasing partial treatment of process water through the membrane network increases reusability water within the process, thereby reducing freshwater intake. However, increased partial treatment of water requires more energy for the membrane network, hence the trade-off between energy and water. The adopted approach deviates from the established black-box techniques and considers detailed design of the selected types of membranes. Electrodialysis and reverse osmosis membrane systems are considered in this lecture. Also presented, is a recent continuous-time scheduling framework that captures time in its exact form in multipurpose batch chemical plants. The latter is capable of addressing all the known idiosyncratic features of batch plants, stemming from various combinations of operational philosophies, including Process Intermediate Storage (PIS) and Finite Intermediate Storage (FIS) operational philosophies. Case studies drawn from different chemical industrial sectors are presented to illustrate applicability of the developed mathematical framework.
Biography
Thokozani Majozi is a full professor in the School of Chemical and Metallurgical Engineering at Wits University where he also holds the NRF/DST Chair in Sustainable Process Engineering. His main research interest is batch chemical process integration, where he has made significant scientific contributions that have earned him international recognition. Some of these contributions have been adopted by industry. Prior to joining Wits, he spent almost 10 years at the University of Pretoria, initially as an associate professor and later as a full professor of chemical engineering. He was also an associate professor in computer science at the University of Pannonia in Hungary from 2005 to 2009. He spent his early years of his professional career as a chemical engineer working for Unilever, Dow AgroSciences and Sasol Technology. Majozi completed his PhD in Process Integration at the University of Manchester Institute of Science and Technology in the United Kingdom. He is a member of Academy of Sciences of South Africa and a Fellow for the African Academy of Sciences. He has received numerous awards for his research including the Burianec Memorial Award (Italy), S2A3 British Association Medal (Silver) and the South African Institution of Chemical Engineers Bill Neal-May Gold Medal. He is also thrice a recipient of the National Science and Technology Forum Award and twice the recipient of the National Research Foundation President’s Award. Majozi is author and co-author of more than 190 scientific publications, including 3 books in Batch Chemical Process Integration published by Springer and CRC Press.