Application of Carbon Recycling Iron-making System in a Shaft Furnace

• Kato Yukitaka

  Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology

• Ujisawa Yutaka

  Ironmaking Technology Div., Nippon Steel and Sumitomo Metal Corporation

• Sakai Hiroshi

  Research & Development, Nippon Steel and Sumitomo Metal Corporation

• Inada Takanobu

  Department of Mechanical Engineering, Ishikawa National College of Technology

Abstract

An active carbon-recycling energy system (ACRES) has been proposed to reduce emission carbon dioxide (CO₂) emission from industrial energy processes. Application of a smart iron-making system based on ACRES (iACRES) in a shaft furnace is modeled numerically as a new low-carbon process. It was assumed that a proportion of the CO₂ in the furnace gas was extracted via gas separation, and reduced into carbon monoxide (CO) by electrolysis, after which regenerated CO was mixed with a reduction gas and recycled continuously in the furnace. The use of a solid oxide electrolysis cell (SOEC) was assumed for the electrolysis process. A one-dimensional model for the shaft furnace was employed for feasibility evaluation of the carbon recycling process.<br>The mixing ratio of electrolysis gas, m [–], was defined as the flow amount of CO₂ separated from the furnace gas for recycling (which was electrolyzed into CO/CO₂ mixture) relative to total inlet reduction gas for the furnace. Electrolysis degree, ed [–], was defined as CO production yield by electrolysis of the separated CO₂. The effects of m and ed on the reduction process in the furnace were evaluated. At ed > 70%, metallization degree of > 90% was maintained at m > 10%. The furnace system was envisaged as a pre-reduction process for iron-ore material. When 70% metallization was acceptable for the pre-reduction process, m of 14% was achievable even at ed of 40%. The value of m is equal to primary fuel saving. It is expected that the shaft furnace with iACRES would have potential as a low-carbon iron-making process.

Journal

• ISIJ International

  ISIJ International 55 (2), 359-364, 2015

  The Iron and Steel Institute of Japan

Keywords

• carbon recycling
• iACRES
• shaft furnace
• carbon dioxide
• carbon monoxide

Details

• CRID: 1390282681465465216
• NII Article ID: 130004734550
• DOI: 10.2355/isijinternational.55.359
• ISSN: 13475460
• ISSN: 09151559
• Web Site: https://www.jstage.jst.go.jp/article/isijinternational/55/2/55_359/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed