Global optimization of an industrial natural gas production network∗

A new stochastic programming model is proposed for integrated design and operation of natural gas production networks under uncertainty. The model not only addresses the uncertainties explicitly, but also considers the gas compositions and pressure-flow relationships for the whole production network. Due to the many nonconvex constraints, the new model leads to a very difficult large-scale nonconvex mixed-integer nonlinear programming (MINLP) problem. A modified nonconvex generalized Benders decomposition (NGBD) method is developed to efficiently solve this problem. This method integrates in NGBD several bound contraction strategies, which render tighter convex relaxations for constructing tighter lower bounding problems and accelerating the solution of nonconvex subproblems. Case study of an industrial natural gas production system shows the benefits of the proposed stochastic model and the bound contraction integrated NGBD method.