Methodology for optimization of operation to reduce site-scale energy use in production plants

Abstract

A methodology was developed to improve energy usage in the process industries by optimizing plant operation. The first step was to build fine tuned site-scale models of energy intensive production plants and of combined heat and power utility distribution networks (heat, power, cooling), and later to optimize them using various numerical techniques. The methodology not only comprises these models, but also the selected optimization methods, their implementation in algorithms suited for the problems to be solved and the evaluation of the results in terms of their applicability in real industrial problems. The detailed models were tuned on the basis of actual plant data. They were used to calculate accurate energy balances, and thus to identify sources of energy waste. Finally they allowed optimization of energy usage by adjusting operating conditions at a medium time scale (a few hours to a couple of days). Energy savings in the range 5%–10% could be obtained for energy intensive processes, where even a low percentage represents a considerable amount.