Influence of Large Amount of Hydrogen Containing Gaseous Reductant Injection on Carbon Consumption and Operation Conditions of Blast Furnace - Development of Low Carbon Blast Furnace Operation Technology by using Experimental Blast Furnace: part II -

Abstract

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.