Process integration in energy and carbon intensive industries: An example of exploitation of optimization techniques and decision support

Abstract Process industries show an ever-increasing interest in reducing their environmental impact and energy consumption as well as in maintaining an acceptable profit. This is particularly true for industries such as the steel one, which is among the highest energy consumers worldwide. Process modelling and optimization are techniques by which this problem can be effectively addressed, particularly if the overall system is optimised as a whole. This article describes the exploitation of a tool for optimization of the process gas network in an integrated steel plant. The main sub-plants are modelled in order to calculate mass and energy balances in different scenarios of operation. The scenarios are then exploited within a multi-objective optimization problem, where cost and CO2 emissions are simultaneously minimised. The optimization is carried out by exploiting evolutionary algorithms that enable a flexible problem formulation and the effective generation of a set of different trade-off solutions. Application of the model to industrial case studies results in interesting potentials for reduction of CO2 emissions and costs. The described software is a helpful tool for plant managers in their daily decision-making process.