Optimal Operation of Electric Arc Furnaces (EAF) to Minimize the Generation of Air Pollutants at the SourceEPA Grant Number: R826736
Title: Optimal Operation of Electric Arc Furnaces (EAF) to Minimize the Generation of Air Pollutants at the Source
Investigators: Ramirez, W. Fred
Institution: University of Colorado at Boulder
EPA Project Officer: Richards, April
Project Period: October 1, 1998 through October 1, 2001
Project Amount: $109,305
RFA: Technology for a Sustainable Environment (1998) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
Description:The manufacture of steel by electric arc furnaces (EAF) is continuing to increase in usage in the United States with current production estimated to be over 63 million tons per year. The reduction of emissions from steel producers has been slow for two main reasons: the need to maintain or increase current production levels and the lack of understanding and control of the steel-making process.
The EAF holds a three-phase system of liquid (molten steel), slag (metal oxides), and gas with both mass and heat transfer taking place amongst the three. The furnace operations, or controls, include carbon injection, oxygen lancing, burner operation, and air infiltration. The controls are used to produce the appropriate grade of liquid steel at a requested temperature.
Approach:We propose to develop a dynamic model of the electric arc furnace consisting of melting, equilibrium chemistry, and material balance sub-models. The EAF model will include all of the furnace operations involved in an industrial furnace. Preliminary investigations into the control of the furnace to minimize carbon monoxide emissions have shown that the system is extremely sensitive to carbon injection and burner oxygen controls. These results show great promise for the improvement of furnace performance, which includes environmental impact and energy consumption.
Expected Results:With the collaboration of industrial companies, we propose a three-year research program which includes model development, model verification and calibration, and dynamic optimization of the process. This work addresses the EPA's Common Sense Initiative toward finding better environmental production methods for the steel industry. The final result of the research will be a closed-loop optimal control system that can minimize environmental impact and energy consumption while maintaining profitability. This project will lead to operational policies for electric arc furnaces that allow for pollution prevention by minimizing the generation of air pollutants at the source. This pollution prevention approach is general and can be applied to numerous chemical processes in addition to a wide variety of electric arc furnaces used in the steel industry and the processing of elemental phosphorous for the manufacturing of pesticides and food products.
Improvements in Risk Management: By minimizing energy consumption, profitability is enhanced and the production of greenhouse gases is minimized. A new multivariate feedback control methodology is proposed that will allow for the on-line operation of electric arc furnaces to reduce the generation of air pollutants. Our approach of process modeling and dynamic optimization is a general systems approach to pollution prevention for batch processes.