Degradation Behavior of Coke Reacting with H&lt;sub&gt;2&lt;/sub&gt;O and CO&lt;sub&gt;2&lt;/sub&gt; at High Temperature

Wang, Ping; Zhang, Yue-qiang; Long, Hongming; Wei, Rufei; Li, Jiaxin; Meng, Qingbang; Yu, Shu-cai

doi:10.2355/isijinternational.isijint-2016-488

Cited by 35 publications

(18 citation statements)

References 10 publications

(12 reference statements)

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“…For example, the CSR of coke A decreases from 60.6% to 39.6%, and the CSR of coke B decreases from 71.3% to 50.3%. The above changes of CRI and CSR of reacted cokes are consistent with the findings of Wang et al, 24 indicating that the damage of H 2 O on cokes is larger than that of CO 2 , which is mainly due to the faster reaction rate of cokes with H 2 O. The faster gasification rate will lead to more consumption of the carbon matrix at a certain time and then cause greater serious damage to the coke structure.…”

Section: Resultssupporting

confidence: 89%

“…Furthermore, the coke strength after reaction (CSR) with H 2 O was lower than that with CO 2 at 950−1100 °C, but higher at 1200 °C. 23,24 temperature. The gasification reaction control mechanism of coke varied with the gas type and the reaction temperature.…”

Section: Introductionmentioning

confidence: 99%

“…According to the study of Wang et al, the reaction of coke with H 2 O occurred more strongly at the exterior compared to the reaction with CO 2 . Furthermore, the coke strength after reaction (CSR) with H 2 O was lower than that with CO 2 at 950–1100 °C, but higher at 1200 °C. , In order to clarify the difference of the coke gasification reaction with CO 2 and H 2 O, Guo et al conducted the kinetic analysis of gasification of coke under CO 2 or H 2 O. On the basis of the results, the reaction rate of coke with H 2 O is about 2–4 times faster than that with CO 2 at the same temperature.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Xu¹,

Dai²,

Wang³

et al. 2018

Energy Fuels

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The metallurgical properties and the microstructure of coke after gasification reaction with pure H2O and pure CO2 were investigated in this study. Moreover, the first-principles calculation was conducted to study the reaction process of the carbon with pure H2O and pure CO2. The results show that the CRI (coke reaction index) increases sharply and the CSR (coke strength after reaction) decreases sharply, when the cokes are gasified with H2O as compared to CO2. The scanning electronic microscopy images and the coke panoramagrams show that H2O more easily leads to the generation of large pores (>500 μm) and destroys the coke structure than CO2. The X-ray diffraction results indicate that the arrangement of carbon atoms of coke becomes regular and the ordered degree of coke increases after reaction with CO2 and H2O; however, after being gasified with H2O, the cokes have a higher ordered degree than with CO2. The results of the first-principles calculation show that the H2O molecule is more likely to react with carbon as compared to the CO2 molecule due to the lower energy barriers of H2O adsorption and H2 formation. The M2 → FS reaction process is the controlled step of the C-H2O reaction process, as well as in the C-CO2 reaction system.

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Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Xu¹,

Dai²,

Wang³

et al. 2018

Energy Fuels

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“…13) Wang et al performed the gasification experiment of coke with CO 2 or H 2 O at the reaction temperatures of 1 223-1 523 K and investigated the change of pore structure by reaction through the measurement of bulk density of coke. 14) This result showed that at high temperature, the gasification reaction proceeded more around the external surface than at internal area regardless of the reactant gas. On the other hand, at low temperature, the difference of the structural change between at internal area and around external surface was small.…”

Section: Introductionmentioning

confidence: 91%

“…This concentration distribution caused the selective vanishment of carbon voxels around the external surface. Therefore, the difference of the structure after reaction by reaction temperature as shown in the previous experimental studies 14,30) was numerically expressed.…”

Section: Change Of Coke Structure and Gas Concentrationmentioning

confidence: 99%

Numerical Investigation for the Temperature Dependency of Coke Degradation by CO<sub>2</sub> Gasification Reaction in a Blast Furnace

et al. 2020

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To quantitatively evaluate the temperature dependency of coke degradation by CO 2 gasification reaction in a blast furnace, kinetic analyses of gasification reaction with mass transfer for the coke model with approx. 200 million voxels developed from X-ray CT images at the reaction temperatures of 1 373, 1 573, 1 773 and 1 973 K were performed. At high reaction temperature, the gas concentration of CO 2 was high in the external area of the coke model, and the coke matrix voxels vanished mainly around the external surface. Distinguishing surface area of interface between a carbon matrix voxel and a pore voxel with the gas concentration of CO2 at a neighbor pore voxel, although the surface area with the high gas concentration of CO 2 accounted for the majority of the total surface area at 1 373 K, the ratio was lower at over 1 573 K than at 1 373 K. In addition to this, from the effectiveness factor of catalyst, the initial rate-controlling step was chemical reaction at 1 373 K but pore diffusion at over 1 573 K. Also, although the frequency distribution of local porosity showed unimodal regardless of the progress of reaction, the standard deviation calculated from the distribution was changed by reaction. The change rate of the standard deviation by reaction seemed to be larger at high reaction temperature than at low reaction temperature. The logarithm of the change rate hardly depended on reaction temperature under 1 573 K but was proportional to the inverse of the temperature over 1 573 K. This study quantitatively showed that the rate-controlling step affects the coke structure after reaction largely.

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Effects of Adding Different Proportions of H₂ to the Simulated Hydrogen‐Rich Blast Furnace

Fan

Wang³

et al. 2022

Chem Eng & Technol

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The volume‐fraction changes of CO2 and H2O after adding different proportions of H2 to the hydrogen‐rich blast furnace were simulated by thermodynamic calculations to evaluate the effects of H2 on coke gasification in a blast furnace. Thermodynamic calculations indicated that the H2O content in the mixed gas gradually increased with higher H2 content. The coke gasification kinetics effective diffusion coefficient De and interfacial reaction rate constant k+ of the coke gasification reaction improved with higher H2 content. In addition, the reactivity of cokes enhanced and the coke strength after reaction decreased with higher H2 content. Mercury porosimeter experiments demonstrated that the coke gasification reaction mainly occurred on the surface.

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Degradation Behavior of Coke Reacting with H<sub>2</sub>O and CO<sub>2</sub> at High Temperature

Cited by 35 publications

References 10 publications

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Numerical Investigation for the Temperature Dependency of Coke Degradation by CO<sub>2</sub> Gasification Reaction in a Blast Furnace

Effects of Adding Different Proportions of H₂ to the Simulated Hydrogen‐Rich Blast Furnace

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Degradation Behavior of Coke Reacting with H<sub>2</sub>O and CO<sub>2</sub> at High Temperature

Cited by 35 publications

References 10 publications

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H2O/CO2 Atmosphere

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H2O/CO2 Atmosphere

Numerical Investigation for the Temperature Dependency of Coke Degradation by CO<sub>2</sub> Gasification Reaction in a Blast Furnace

Effects of Adding Different Proportions of H2 to the Simulated Hydrogen‐Rich Blast Furnace

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Product

Resources

About

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Gasification Reactivity and Structure Evolution of Metallurgical Coke under H₂O/CO₂ Atmosphere

Effects of Adding Different Proportions of H₂ to the Simulated Hydrogen‐Rich Blast Furnace