Operation Trial of Hydrogenous Gas Injection of COURSE50 Project at an Experimental Blast Furnace

Abstract

COURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) carried out COG and reformed COG (RCOG) injection operation trials at LKAB's experimental blast furnace in Luleå in cooperation with LKAB and Swerea MEFOS. Operation trials were successfully carried out. Input of C in both COG and RCOG injection periods decreased comparing the base period, because of increase in H2 reduction instead of C direct reduction that is a huge endothermic reaction. However poor penetration depth of injected gas from shaft tuyere made furnace efficiency worse. Hot top gas injection increased temperature of top gas and upper part of the furnace. Efficiency of hot top gas injection was not clear as sinter degradation did not occur in the base period.KEY WORDS: COURSE50; experimental blast furnace; blast furnace; CO2 emission; H2; COG; reformed COG; injection; hot top gas; sinter degradation. PrefaceCOURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) is a national project for development of technologies for environmentally harmonized steelmaking process to achieve drastic CO2 emissions reduction in steel industry. Main targets of COURSE50 project are development of technologies to reduce CO2 emissions from blast furnace and development of technologies to capture, separate and recover CO2 from blast furnace gas. CO2 reduction technology from blast furnace consists of research of control reactions for reducing iron ore with hydrogenous reducing agents such as coke oven gas (COG) or reformed COG (RCOG). RCOG is amplified its hydrogen content in COG by utilizing newly developed catalyst and unused waste heat. Also a technology to produce high strength and high reactivity coke for reduction with hydrogen is under development.RCOG will be injected to the blast furnace through tuyeres located at lower part of the shaft of blast furnace, and COG will be injected through blast tuyeres to utilize CH4 combustion.Amount of O2 enrichment to the hot blast air has to be increased when COG is injected to the blast tuyere to maintain the flame temperature constant to compensate for heat of decomposition of hydrocarbon. It results in decrease in upper part temperature and decreased upper part temperature prolongs the residence time for sinter where disintegration is promoted. In addition, H2 may promote sinter deterioration. To prohibit prolonged residence time for sinter at low temperature range, top gas is partly combusted is injected in the upper shaft for temperature control. We call it hot top gas injection in this article.Basic and remarkable results are conducted through various laboratory tests and mathematical model calculation in COURSE50 project.3,4) H2 in COG or RCOG is expected to react with ferrous material very fast and to replace C as reducing agent of blast furnace.However, reaction in the blast furnace is much complicated because it is dominated by burden and gas distribution

Fate of Nitrogen and Sulfur during Reduction Process of Carbon-containing Pellet Prepared by Vapor Deposition of Gaseous-Tar and the Influences of the Hetero Elements on the Reduction Behavior and Crushing Strength

“…8) If a composite with large amounts of C, a high crushing strength, high reduction reactivity, and low RDI can be prepared gaseous-tar, it may be applicable for blast furnaces in conventional or advanced iron-making processes (COURSE50). [9][10][11] For the above-mentioned composite preparation, it is considered that the utilization of the conventional process is effective. In other words, if COG containing gaseous-tar produced from the cokemaking process and its sensible heat can be utilized for composite preparation, the production can be completed in integrated iron steel plants.…”

Evolution of Blast Furnace Process toward Reductant Flexibility and Carbon Dioxide Mitigation in Steel Works

“…In addition to conventional carbon reduction and energy saving techniques, many studies on novel technologies for reducing CO 2 emissions from the steel works are being carried out from the mid-and longterm viewpoints. [1][2][3][4][5] Although the evolution of the blast furnace with the aim of realizing low carbon in the steel works has attracted considerable attention from the viewpoint of reducing CO 2 emissions, a more proactive fundamental review of the ironmaking process is needed. From these various viewpoints, technology development to reduce carbon consumption in the blast furnace is considered to be a priority issue for the steel works.…”

Sustainable Aspects of CO2 Ultimate Reduction in the Steelmaking Process (COURSE50 Project), Part 1: Hydrogen Reduction in the Blast Furnace

“…The diameter of the shaft tuyere was 32 mm, and the gas velocity was approximately 45 m/s at an injection rate of 225 Nm 3 /h. The penetration depth of RCOG into the furnace was detected using the lower shaft probe located 1.16 m above the shaft tuyere level [5].…”

“…Since FY2008, we have promoted technology development through the innovative COURSE50 (CO 2 Ultimate Reduction in Steelmaking process by innovative technology for cool Earth 50) R&D program [1][2][3][4][5][6], which aims at mitigating CO 2 emissions in the ironmaking process. Figure 1 shows an outline of the COURSE50 project and its two major research activities.…”