Automated optimization model to perform sensitivity analysis on cost of investment required to upgrade treatment plants in water networks.

摘要

A new methodology based on the mathematical programming model by Ahmetovic and Grossmann (2011) is proposed. It involves optimization in two levels: minimize the total flow of fresh water and treatments, and minimize total annualized cost including the installation of the new treatment plant cost, the wastewatcr treatment costs and the fresh water cost. The results obtained with this methodology provide the minimum investment in terms of different technologies for water regeneration and bottlenecks presented by the nature of the contaminants. A versatile software program has been developed implementing these optimization models. A Graphical User Interface (GUI) based on Windows™ is designed for data entry while the models are automatically generated and interfaced with the mathematical modeling system GAMS™. Selected scenarios and technologies can be studied for real size water distribution networks from different chemical process industries: Gas Processing, Petroleum Refineries and Petrochemical Complexes. An illustrative example is presented. From the results we can conclude that the total annualized cost is highly sensitive to two main treatment units, the demineralization plant and the cooling water blow down treatment for regeneration. We also performed a sensitivity analysis of the overall effect that different technologies have for treatment plants and the limits for environmental standards regulations in Mexico by the year 2020.