2022 Volume 62 Issue 12 Pages 2433-2441
COURSE50, CO2 Ultimate Reduction System by Innovative technology for cool Earth 50, is the national project for reduction of CO2 emission from steelworks in Japan. Three steel companies and one engineering company join this project supported by NEDO (New Energy and industrial technology Development Organization). The target of COURSE50 is reduction of CO2 emission from steel works over 30%, 20% by CCS (Carbon Capture and Storage) and 10% over by operation of blast furnace. In order to realize the reduction of CO2 emission form blast furnace over 10%, H2 utilization technology has been developing using 12 m3 experimental blast furnace. The experiments have been taking place form 2016. From 2016 to 2017, 10% reduction of CO2 emission achieved by using three methods, gaseous reductant injection from tuyeres, gaseous reductant injection from shaft tuyeres, and high reducibility sinter charging. In order to improve the reduction CO2 emission technology, hydrogen-based gaseous reductants were used form 2018. Five campaigns were taken placed from 2018 to 2020. An unprecedented amount of H2 gas in the world was injected in the experimental blast furnace. As a result, it is clarified that direct reduction rate was fell and H2 reduction rate was raised straightly as amount of H2 input was increased. Also, the reduction rate of CO2 emission was affected by the amount of hydrogen injection. About 16% of CO2 emission was reduced with 359 Nm3/t-HM of H2 injection.