An MILP-based Operability Approach for Process Intensification and Design of Modular Energy Systems

Abstract A mixed-integer linear programming (MILP) operability approach is developed for the design of high-dimensional and nonlinear systems. For the approach formulation, classical operability concepts are extended to attain process intensification towards system modularity. Motivated by natural gas utilization processes, a catalytic membrane reactor for the direct methane aromatization (DMA-MR) conversion to hydrogen and benzene is chosen as case study. The DMA-MR is described by a system whose design is challenged by complexity, including nonlinearities and a highly-constrained environment. A DMA-MR subsystem is addressed, for which 80% reduction in membrane area and 78% reduction in reactor volume is obtained when compared to a base case with equivalent performance. The proposed approach presents a computational time reduction greater than 3 orders of magnitude compared with previously introduced nonlinear programming-based operability approaches. These results indicate that the proposed approach is computationally efficient and thus can be extended to address higher dimensional cases.