Processing facilities are characterized by the use of tremendous amounts of material resources. If not managed properly, such enormous usage can lead to the depletion of natural resources poses many economic, social, and ecological challenges. Therefore, the process industries have embarked on major material conservation initiatives to enhance market competitiveness and sustainability. Several strategies can lead to material conservation including segregation, mixing, recycle/reuse, material substitution, reaction alteration, and process modification. In this chapter, we focus on stream rerouting including segregation, mixing, and recycle/reuse. Segregation refers to avoiding the mixing of streams. Segregation of streams with different compositions avoids unnecessary loss of driving force of streams. Such management of driving forces enhances the performance of process units (e.g., separators) and can also provide composition levels that allow the streams to be recycled directly to process units. Recycle refers to the utilization of a process stream (e.g., a waste or a low-value stream) in a process unit (a sink). While reuse is distinguished from recycle by emphasis that reuse corresponds to the reapplication of the stream for the original intent, we will use the term recycle in a general sense that includes reuse. In particular, we will start with direct recycle where the streams are rerouted without the installation of new devices. Direct-recycle is typically classified as low cost strategies, since it basically involves pumping and piping and in some cases may even be achieved without the need for additional pumping or piping.

First, a targeting technique will...