Graphitisation effect of coke with changing annealing time and temperature on pore structure and apparent gasification rate with H₂O

Abstract

The effect of graphitisation by the variation of annealing time and temperature on the pore structure and apparent gasification rate at 1200 and 1500°C was investigated. The graphitisation degree of three kinds of coke used in this study was increased with annealing time and temperature. The increase in porosity of annealed coke sample is ascribed to the formation of silicon carbide. Annealing at 1200°C had less significant effect on the change of porosity in comparison with annealing at 1500°C. The mean area of pores was decreased, and pore density was increased with increasing annealing time while annealing had marginal influence on the pore shape. The apparent gasification rates of Coke 1 and Coke 2 with H 2 O were decreased by annealing, but 3 h of annealing increased the apparent gasification rate of Coke 3. The correlation between apparent gasification rate with H 2 O and macroporosity or graphitisation degree was investigated.

Pore Structure and Integrity of a Bio-Coke under Simulated Blast Furnace Conditions

“…After annealing at high temperatures, SiC was the major phase in the coke mineral formed through carbothermal reduction of quartz according to the reaction The standard Gibbs energy change of reaction is negative at temperatures above 1525 °C. However, the formation of SiC was also determined at lower temperature . The equilibrium partial pressures of CO in eq at 1400 and 2000 °C were calculated as 0.25 and 64.61 atm, respectively.…”

Effect of the Moisture Content of Coal Blends on Coke Structure and its Apparent Gasification Kinetics with CO₂

“…Ziming WANG, 1) Kejiang LI, 1) * Jianliang ZHANG, 1,2) Xuehong ZHANG, 3) Gaifeng XUE, 3) Xitao CHEN, 3) Minmin SUN 1) and Chunhe JIANG 1) 1) School of Metallurgical 16,2020) In this work, the influences of moisture content of coal on the structure and reactivity of cokes were investigated by blending different proportion of dry coal (with < 2 wt.% moisture) and wet coal (with ~10 wt.% moisture) and analyzing the gasification of the produced coke. The results indicated the coke formed from dry coal has the highest specific surface area and thinner pore walls.…”

“…1,2) Coke gasification reaction is the most important factor in coke quality degradation, and these factors depend on the carbon structure, minerals, the morphology and connectivity of the pores. [2][3][4][5][6] In addition, the coking process of coal directly affects the performance of coke.…”

Positive Catalytic Effect and Mechanism of Iron on the Gasification Reactivity of Coke using Thermogravimetry and Density Functional Theory

“…Even though the mineral content is typically ˂15 wt%, it can significantly influence the reactive behaviour of coke in BF, especially during gasification with CO 2 . [2][3][4][5] Alkali and alkaline earth metals have a positive effect on the coke gasification process. [5][6][7][8] Catalytic gasification can reduce the initial gasification temperature and enhance coke reactivity, but the coke strength after reaction (CSR) is often reduced.…”