Simultaneous synthesis of multi-plant heat exchanger networks using process streams across plants

Interplant heat integration using process streams is an alternative way to synthesize multi-plant heat exchanger networks (HENs). Compared with conventional way using steam, directly using process stream can recover more heat but with more pipelines. Due to the geographically separated locations of individual plants, distance related factors should be fully considered. In addition, the interaction between interplant heat integration and intra-plant heat integration is not fully addressed in traditional design methods. To counter these limitations, we present a new methodology for multi-plant HENs synthesis directly using process streams. The methodology makes use of a generalized disjunctive programming (GDP) formulation which gives rise to a mixed-integer nonlinear programming (MINLP) problem. For illustration purpose, two literature problems are conducted to verify the applicability of the proposed methodology. Our results can automatically offer the optimal design for multi-plant HENs, which are both more cost-optimal than the ones reported in the cited literatures.