Improving fuel utilization in steel mill operations using linear programming
Abstract This paper describes the use of linear programming to improve the fuel utilisation at a major Midwestern steel mill. In particular, linear programming is used to determine an efficient fuel allocation plan for this steel mill, which reduces the total fuel costs for the steel mill operations. The efficient fuel allocation plan that is developed utilises two externally purchased fuels: natural gas and fuel oil, and two gases: blast furnace gas and coke plant gas, which are internally generated as natural by-products of the production process. Test results from the application of the linear programming model are presented and discussed, and indicate that considerable cost savings can be achieved by utilizing a fuel allocation plan which more effectively utilizes the by-product gases which are produced within the steel making process.
CONTROL OF GASHOLDER LEVEL BY TREND PREDICTION BASED ON TIME-SERIES ANALYSIS AND PROCESS HEURISTICS
A novel method to control gasholder levels in an iron and steel company with accurate prediction of future trend is presented. Although various gasholders are used to recycle by-product gases generated during iron-making, coke-burning and steel-making process, the capacity of the gasholders are insufficient to handle large amount of the gases. To overcome this problem, tight control of the gasholder level should be conducted by predicting their anticipated changes. However, the current prediction logic cannot show satisfactory results due to the lack of characterization of relevant processes. In the proposed method, time-series modeling and heuristics of industrial operators are used to correctly reflect the process characteristics and deal with unexpected process delays. By applying the proposed method to an off-line data set, a significant reduction of discrepancy between predicted values and actual values has been observed. The method is expected to be adopted in the prediction system of POSCO. Copyright © 2002 IFAC
Study on the gaseous emissions from a landfill
Abstract Emissions from landfills contain a variety of compounds, organic and inorganic, which can create problems with human health. Here we examine the pollutants methane, hydrogen sulphite, mercaptans, sulphur dioxide, nitrogen dioxide and certain volatile organic compounds (VOCs) that are expected to be found in landfill emissions, in order to assess the environmental impact on the surrounding area. Results indicate that the concentrations in the landfill itself are quite high and in most cases above the ambient air quality limits, while for the surrounding area they are low. The problem is created by H 2 S and the mercaptans which, although in low content, have a distinct odour and cause problems to the neighbouring dwellings.