A novel disjunctive model for the simultaneous optimization and heat integration

- An alternative disjunctive model for simultaneous optimization and heat integration.
- It allows the possibility of selecting and using different utilities.
- The novel disjunctive reformulation has a good relaxation gap.
- Examples with different complexity illustrate the performance of the novel approach.

This paper introduces a new disjunctive formulation for the simultaneous optimization and heat integration of systems with variable inlet and outlet temperatures in process streams as well as the possibility of selecting and using different utilities. The starting point is the original compact formulation of the Pinch Location Method, however, instead of approximating the “maximum” operator with smooth, but non-convex functions, these operators are modeled by means of a disjunction. The new formulation has shown to have equal or lower relaxation gap than the best alternative reformulation, thus reducing computational time and numerical problems related to non-convex approximations.