A Capex Opex Simultaneous Robust Optimizer: Process Simulation-based Generalized Framework for Reliable Economic Estimations

During the design of a process, the most economically impactful choices are often taken with limited data and details available on the specifics of unit operations. Despite this fact, the effect some of these choices have on the final economic performance of the plant can be dramatic and far more influential than later decisions. The availability of fast and reliable preliminary cost estimations based on few key design parameters for the most common units can go a long way in improving flowsheet design. Due to the early design stage, these estimates don't need to be very accurate since errors in the range of 50% are admissible as long as the estimation requires few input data. Automating the costs computation process and making the interface with the most common simulation packages standardized and easily accessible for users not accustomed to programming languages is very important in speeding up the cost evaluation of the plant and reducing the human resources tied to this task. These concepts stand at the core design of the CAPEX OPEX Robust Optimizer (CORO) developed in this work. Aspen HYSYS serves as the commercial simulation package to estimate the input variable of the economic libraries. Excel is used both as a GUI and as a data extraction tool from Aspen HYSYS due to its widespread diffusion in industry and versatility provided by Visual Basic for Applications. The CORO code is detached both from Excel and HYSYS and interacts only with a standardized xml data sheet to allow for in-house expansions to other simulation packages. The long-term development goal is a generalized CAPE-OPEN interface working with every commercial software that supports the interface. In the current CORO release, the interface can interact only with Aspen HYSYS. This paper will showcase the economic libraries implemented in CORO, the mathematical C ++ optimization libraries, the overall structure of the tool, planned future expansions, and customization options.