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. (C) 2013 Elsevier Ltd. All rights reserved.