Kinetic Study on Continuous Sampling of Coal Char from a Micro Fluidized Bed

Li, Zehua; Zou, Renjie; Xu, Yang; Cao, Liang; Luo, Guangqian; Yao, Hong

doi:10.1021/acsomega.1c00131

Cited by 5 publications

(14 citation statements)

References 42 publications

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“…The reaction rate constant k is the slope of the fitting straight line. The shrinking core model fits the results well from our previous studies 8,15,23 and other researcher's studies. 38,39 Therefore, the shrinking core model (eq 4) was selected as the mechanism function model in this study.…”

Section: Reaction Rate Constant Determinationsupporting

confidence: 86%

“…The details of the system could be found in our previous study. 23 The reactant gas was injected into the reactor from the bottom. Steam was produced by a steam generator, which could adjust the flow of the steam.…”

Section: Methodsmentioning

confidence: 99%

“…However, the semi-char reactivity follows a trend of decrease−increase−decrease. 23 4.2. Semi-Char Burnout Rate.…”

Section: Reaction Rate Constant Determinationmentioning

confidence: 99%

“…20−22 Focusing on this point, we recently reported a microfluidized bed (MFB) reactor combining the continuous solid particle vacuum sampling technique. 23 The reactivity of the semi-char was reported to follow the trend of decrease− increase−decrease and the activation energy increased with the proceeding of combustion. 23 In the present study, we will further investigate the effect of CO 2 /H 2 O in recycled flue gas on semi-char properties in oxysteam combustion using a continuous semi-char particle sampling system.…”

Section: Introductionmentioning

confidence: 99%

“…23 The reactivity of the semi-char was reported to follow the trend of decrease− increase−decrease and the activation energy increased with the proceeding of combustion. 23 In the present study, we will further investigate the effect of CO 2 /H 2 O in recycled flue gas on semi-char properties in oxysteam combustion using a continuous semi-char particle sampling system. Basically, compared to the fixed bed reactor and drop tube furnace, the MFB reactor shows sufficient mass and heat transfer and is usually applied to the isothermal reactions for kinetic studies.…”

Section: Introductionmentioning

confidence: 99%

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Effect of CO₂ and H₂O on Char Properties. Part 3: Semi-Char from Continuous Sampling in a Microfluidized Bed

Zou

et al. 2021

Energy Fuels

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Oxy-steam coal combustion is performed in an atmosphere with a mixture of O 2 , CO 2 , and H 2 O. In this case, both CO 2 and H 2 O in the cyclic flue gas may have an influence on coal char properties in either pyrolysis or combustion. In a traditional combustion reactor, coal char reactivity is usually measured from a whole reaction view, where we could not identify the behavior of the semi-char during the combustion itself. This study reported a microfluidized bed reactor, which combines a solid char particle online sampling system. Semi-char was continuously sampled out from the reactor. The effect of CO 2 /H 2 O on semi-char properties and reactivity was investigated. The results show that the activation energy of the semi-char increases during oxy-steam combustion. In the early combustion stage, the reactivity of the semi-char is higher than that of the original coal char and increases with the sampling time, which is due to the increase of the disordered carbon. While the CO 2 partial pressure has little influence on the reaction index R s of the semi-char, the H 2 O partial pressure has a positive effect on R s . Compared to CO 2 , H 2 O has a greater influence on semi-char reactivity.

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