Simultaneous optimization of energy management, biocide dosing and maintenance scheduling of thermally integrated facilities

This work presents a systematic approach for the simultaneous optimization of energy supply management, biocide dosing and maintenance scheduling in heat integrated plants considering economic, technical and environmental aspects. The resulting model is a multi-objective mixed integer non-linear programming problem. The considered plants use seawater as cooling fluid above room temperature and a refrigerant below room temperature. One of the main advantages of this work is that it considers not only the economic aspect of the process, but also the technical challenges associated to the use of seawater, the seasonal availability of energy resources and the global environmental impact of the process. The environmental impact is measured through the life cycle analysis of the energy resources (fossil fuels, biofuels and solar energy), expressed in terms of the overall greenhouse gas emissions. A case study for an acrylonitrile plant is solved to show the applicability of the proposed methodology.

► We presented a mathematical programming model for the optimization of thermally integrated processes.
► Sustainable energies can be integrated in processes using seawater and refrigeration as cooling media.
► The optimal plant maintenance scheduling becomes important in these types of plants.
► The Pareto curves obtained help devise attractive solutions in economic, technical and environmental aspects.