A game-theory based optimization strategy to configure inter-plant heat integration schemes

The conventional heat exchanger network synthesis method is useful only for achieving maximum energy recovery (or minimum total annual cost) within a single chemical plant. If the same approach is applied to the hot and cold process streams in more than one plant on an industrial park, the resulting cost savings may be distributed unfairly among all involved parties. A systematic design procedure is developed to circumvent this drawback in the present study on the basis of game theory. Specifically, the inter-plant heat integration scheme is generated in four consecutive steps to determine (1) the lowest acceptable overall utility cost, (2) the proper heat flows between every pair of plants and also their fair trade prices (under the constraints of a lowest acceptable total utility cost and Nash equilibrium), (3) the minimum number of matches and the corresponding heat duties, and (4) the optimal network configuration. This sequential strategy allows every plant to maximize its own financial benefit at every step while simultaneously striving for the largest cost saving for the entire site. The case studies concerning a vinyl chloride process are also presented to demonstrate the feasibility of the proposed approach.