With oxygen enrichment in hot stoves the high calorific coke oven gas can be saved due to the possibility of using lower calorific gases which enables replacement of other imported fuels such as oil or LPG. The application of increased oxygen use in hot stoves or increased O2 in blast, will also potentially lead to lower coke rate. Central to the performance in system optimisation is the ability to analyse and properly describe the system variations. The demand for coke oven gas is depending on both internal operation logistics but it also has outdoor temperature dependence through a heat and power plant producing district heat to the community. An analysis of the influence of increased oxygen enrichment on the entire energy system has been carried out by use of an optimization model. A method of achieving a high time resolution in MILP optimisation is applied in the analysis. Different strategies have been suggested for minimum energy consumption at the studied steel plant and the nearby CHP plant. Copyright © 2011, AIDIC Servizi S.r.l.