Interval-based targeting for pollution prevention via mass integration

Mass integration is a holistic approach to the optimal allocation, generation, and separation of streams and species. It addresses pollution using a combination of strategies including manipulation of process equipment, structural changes in the flowsheet, rerouting of streams and addition of new units. In the past, systematic mass integration techniques were developed to determine optimal strategies for the recycle and separation of process streams. The purpose of this paper is to introduce two novel contributions that can greatly expand the scope of mass integration for pollution prevention. First, maximum achievable pollution targets will be determined ahead of design and with little input data. In this context, we will illustrate the use of interval arithmetic to determine these targets. Second, pollution prevention through unit manipulation will be addressed. The devised interval-based targets posess the attractive feature that they are global regardless of the nonlinearity nature of the process model. These new concepts are illustrated with a case study. © 1999 Elsevier Science Ltd. All rights reserved.