This award supports a cooperative research project between Lorenz Biegler, Department of Chemical Engineering, Carnegie Mellon University, and David Glasser, School of Process and Materials Engineering, University of the Witwatersrand, Johannesburg, South Africa. The project is entitled "Attainable Regions and Mathematical programming for Waste Minimization in Chemical Processes." Process modification to minimize the production of hazardaous and toxic byproducts has captured considerable industrial attention over the past decade. A promising strategy to waste minimization in chemical processes is to develop improved reactor designs and reactor networks that avoid the production of these byproducts in the first place. In this way, the downstream separation and cleanup costs are reduced or even eliminated. To deal with this important problem, the collaborative research effort between Carnegie Mellon University (CMU) and the University of Witwatersrand (WITS) will develop process synthesis strategies that are centered on the reactor network itself. During the past decade, the research group in South Africa has worked on geometric approaches to solving this problem while the US group has developed computational algorithms based on process optimization. This joint venture combines the best of both approaches and plans to develop superior strategies for reactor network design for waste minimizing chemical processes.