POSSIBILITY OF HYDROGEN REDUCTION IN IRON-MAKING PROCESS (Course 50 Programs in Japan)

摘要

Course 50 project is proposed by IISI with 6 major steel industries and related company. Course 50 stands for "CO_2 Ultimate Reduction in Steelmaking Process by Innovative Technology for Cool Earth 50". Basic idea of Course 50 is as follows. The low carbon environment harmony type iron making process development consists of it by development of the hydrogen practical use technology to iron ore reduction and development of cheap production technology of hydrogen (making to dry and amplification technology development of COG). Moreover, the CO_2 separation collection technology development consists of it by CO_2 separation collection technology in blast furnace gas and ironworks rejection heat technology used for CO_2 separation collection. The outline of progress of technological development to use the hydrogen gas for the iron ore reduction is as follows. We attempt the decrease of CO_2 exhausted from the blastfurnace by blowing in reforming COG (The composition example; CO 30% and H2 60%) that contains hydrogen voluminously to the tuyere or the shaft of the blast furnace. It is important to clarify the diffusion behavior and the reduction behavior in the furnace of the hydrogen gas to use hydrogen in reforming COG effectively. The reduction behavior in the furnace was examined with BIS furnace. The result of the reduction efficiency's in the blast furnace improving even when blowing in from either the tuyere or the shaft was obtained. The diffusion behavior in the furnace was examined with a two dimensional experimental apparatus of 1/10 scales of a real furnace. As a result, it was confirmed that diffusion advanced from the furnace wall within the range from about 10 percent to 20 percent. Those results indicated that technology of injection of reformed-COG from shaft had a large possibility of reducing carbon consumption of blast furnaces, resulting in decrease CO_2 emissions in ironmaking process with thanks of higher reaction efficiency of hydrogen reduction compared with that of CO reduction.