2011 Annual Meeting

(763b) Optimization of Blast Furnace Steelmaking Process From a Process Integration Perspective

Authors

Mikko Helle - Presenter, Åbo Akademi University
Henrik Saxén - Presenter, Åbo Akademi University
Hamid Ghanbari - Presenter, Åbo Akademi University
Frank Pettersson - Presenter, Åbo Akademi University


The primary iron and steelmaking systems are one of the major carbon dioxide producers due to coal based procedure. In the last decades, social awareness on carbon dioxide emission has been increased regarding to global warming. There has been lots of effort to increase energy efficiency and suppress the emissions from each unit of the steelmaking system such as ULCOS program which aims to reduce at least 50 percent of carbon dioxide emissions of today’s best routes from steelmaking companies in Europe.

One approach to these propose is by new technologies such as full pellet charging, top gas recycling, cold oxygen injection, fuel injection and enriched-oxygen blast injection in blast furnace which has been studied and some implemented in experimental and industrial scale. Another approach would be focus on renewable energy such as biomass which could reduce dramatically fossil-based emissions. Considering all of these approaches still process integration shows great potential to increase efficiency on the steelmaking systems. Large amount of off gases available from different units such as coke oven gas, blast furnace and based-oxygen furnace top gases could be utilize in a polygeneration system rather than used as a fuel in the combined heat and power unit to produce heat and electricity.

Production of methanol is an option which could be consider as fuel or raw material for other chemical processes and also help to be more flexible due to changes of demand for district heat and electricity in different seasons.

In this study, mathematical modeling and optimization method has been used to utilize the effect of integration on carbon dioxide reduction and methanol production by minimizing the steel production cost. Combination of new technologies such as blast furnace top gas recycling, natural gas injection, cold oxygen injection and oxygen enrichment blast has been applied for different scenarios of emission price and carbon capturing cost.