Fuel enhancement by conversion of hotter waste CO2 in flue gas with coke. (9th August 2019)

• Record Type: Journal Article
• Authors: Xie, Jian-bo; Fu, Jian-xun; Zhou, Lan-hua
• Is Part Of: Ironmaking & steelmaking. Volume 46:Number 7(2019)
• Page Start: 632
• Page End: 641
• Publication Date: 2019-08-09
• Subjects: Fuel gas -- waste heat -- coke injection -- calorific value -- CO2 emissions; Iron industry and trade -- Periodicals; Steel industry and trade -- Periodicals; 669.1
• DOI: 10.1080/03019233.2018.1435605
• Languages: English
• ISSNs: 0301-9233

Abstract

ABSTRACT: Considering the huge losses of high-temperature metallurgical waste heat and gases in steel works and the energy crisis on a worldwide scale, particularly the waste hotter gases in the flue of a converter that are emitted into air. A novel concept where coke is injected into the hotter gases for enhancement of fuel gas and reduction of CO2 emissions into air is proposed. Numerical, experimental and industrial investigations are carried out in this work. The effects of injecting mass rate and inserted depth on the mixed state of coke in the flue were numerically evaluated and the effect of the surface structure of coke on the reactions of gas–solid phases was analysed using the t -plot method, and the transient gas products were described during coke injection. The energy change of the flue gas under various injecting schemes was discussed during the tests. The results show that an injecting scheme comprising an injecting pressure of 1.0 MPa, an inserted depth of 500 mm and an injecting mass rate of 18 kg min −1 seems to be better. The value of the specific surface area of coke was 8.36 m 2 g −1, while the coal was 20.59 m 2 g −1 . With the inserted depth at 400 and 500 mm, the recovery time of the flue gas was 545 and 565 s and the total calorific value accounted for 48.47 and 51.53%, respectively. Without injection, the average contents of CO, O2 and CO2 were 48.1, 1.01 and 23.3, whereas after injection the average contents of CO, O2 and CO2 were 56, 0.5 and 10.1%, respectively. As a result, this process reduces CO2 emissions and increases energy of the flue gas.