Economic assessment of options for biomass pretreatment and use in the blast furnace

Abstract The steel industry still strongly relies on fossil sources of reductants and energy and a considerable part of the global carbon dioxide emissions therefore derives from this industrial sector. Plausible remedies to reduce the emissions are to minimize raw material use and to shift to using renewable energy sources. This paper investigates computationally the options of using biomass as an auxiliary reductant in the blast furnace, and the required pre-processing steps, focusing on energy use and process economics. In order to evaluate the economic feasibility, the problem is tackled as a process optimization task, minimizing the operation costs under different biomass preheating strategies. The paper provides a comparison between two preheating concepts, namely utilization of heat from hot stove flue gases or from combustion of blast furnace top gas. The use of hot stove flue gases reduces the annual operating costs of the preheating by about 0.5 M€ for a plant with a yearly steel production of 1.4 Mt.

[1]  Frank Pettersson,et al.  Optimization of a Steel Plant with Multiple Blast Furnaces Under Biomass Injection , 2013, Metallurgical and Materials Transactions B.

[2]  Hannu Helle,et al.  Nonlinear optimization of steel production using traditional and novel blast furnace operation strategies , 2011 .

[3]  Frank Schultmann,et al.  Assessing the integration of torrefaction into wood pellet production , 2014 .

[4]  R. Kneer,et al.  Torrefaction of beechwood: A parametric study including heat of reaction and grindability , 2013 .

[5]  Abigaïl Fallot,et al.  Assessing land availability to produce biomass for energy: The case of Brazilian charcoal for steel making , 2009 .

[6]  I. Barin,et al.  Thermochemical properties of inorganic substances , 1973 .

[7]  Roberto Schaeffer,et al.  Potential for reduction of CO2 emissions and a low-carbon scenario for the Brazilian industrial sector , 2010 .

[8]  M. Takekawa,et al.  Investigation of waste wood as a blast furnace injectant , 2003 .

[9]  Hannu Helle,et al.  Optimisation study of ironmaking using biomass , 2010 .

[10]  Kj Krzysztof Ptasinski,et al.  Biomass upgrading by torrefaction for the production of biofuels: A review , 2011 .

[11]  Hannu Suopajärvi,et al.  Effects of Biomass Use in Integrated Steel Plant-Gate-to-gate Life Cycle Inventory Method , 2012 .

[12]  Khanh-Quang Tran,et al.  Stump torrefaction for bioenergy application , 2013 .

[13]  Ernst Worrell,et al.  International comparison of CO2 emission trends in the iron and steel industry , 2002 .

[14]  Dieter Senk,et al.  Charcoal Behaviour by Its Injection into the Modern Blast Furnace , 2010 .

[15]  Hannu Helle,et al.  Towards sustainable Iron- and steelmaking with economic optimization , 2014 .

[16]  Chien-Hsiung Tsai,et al.  Torrefied biomasses in a drop tube furnace to evaluate their utility in blast furnaces. , 2012, Bioresource technology.

[17]  S. Mani,et al.  Impact of torrefaction on the grindability and fuel characteristics of forest biomass. , 2011, Bioresource technology.

[18]  Cristobal Feliciano-Bruzual,et al.  Charcoal injection in blast furnaces (Bio-PCI): CO2 reduction potential and economic prospects , 2014 .

[19]  F. G. Emmerich,et al.  Babassu charcoal: A sulfurless renewable thermo-reducing feedstock for steelmaking , 1996 .

[20]  Hannu Suopajärvi,et al.  Towards More Sustainable Ironmaking—An Analysis of Energy Wood Availability in Finland and the Economics of Charcoal Production , 2013 .

[21]  Frank Pettersson,et al.  Optimal Resource Allocation in Integrated Steelmaking with Biomass as Auxiliary Reductant in the Blast Furnace , 2012 .

[22]  Hannu Helle,et al.  Mathematical Optimization of Ironmaking with Biomass as Auxiliary Reductant in the Blast Furnace , 2009 .