A Mixed Integer Linear Programming Model for the Optimization of Steel Waste Gases in Cogeneration: A Combined Coke Oven and Converter Gas Case Study

• Published in: Energies (Basel) Vol. 13; no. 15; p. 3781
• Main Authors: García García, Sergio, Rodríguez Montequín, Vicente, Morán Palacios, Henar, Mones Bayo, Adriano
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.08.2020
• Subjects: allocation; Boilers; Carbon; Case studies; Coal; Cogeneration; Coke; Coke oven gas; Coke ovens; Computer simulation; Decision making; Design; Efficiency; Electric power; Electricity; Electricity distribution; Emissions; Energy; Engines; Exhaust gases; Factories; Gas holders; Gases; Heat; Integer programming; iron and steel industry; Linear programming; Load; Metal industry wastes; MILP modeling; Natural gas; off-gas; Optimization; Ovens & stoves; Potential energy; scheduling; Sensitivity analysis; Steam electric power generation; Steel converters; Steel production; Thermal energy; Thermal power; Spain
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en13153781

Off-gas is one of the by-products of the steelmaking process. Its potential energy can be transformed into heat and electricity by means of cogeneration. A case study using a coke oven and Linz–Donawitz converter gas is presented. This work addresses the gas allocation problem for a cogeneration system producing steam and electricity. In the studied facility, located in northern Spain, the annual production of the plant requires 95,000 MWh of electrical energy and 525,000 MWh of thermal energy. The installed electrical and thermal power is 20.4 MW and 81 MW, respectively. A mixed integer linear programming model is built to optimize gas allocation, thus maximizing its benefits. This model is applied to a 24-h scenario with real data from the plant, where gas allocation decision-making was performed by the plant operators. Application of the model generated profit in a scenario where there were losses, increasing benefits by 16.9%. A sensitivity analysis is also performed. The proposed model is useful not only from the perspective of daily plant operation but also as a tool to simulate different design scenarios, such as the capacity of gasholders.