Transformation and Reactivity of a Potassium Catalyst during Coal–Steam Catalytic Pyrolysis and Gasification

Wang, Xingjun; Zhu, Hui; Xi-min, Wang; Liu, Haifeng; Wang, Fuchen; Yu, Guangsuo

doi:10.1002/ente.201402003

Cited by 14 publications

(12 citation statements)

References 15 publications

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“…Many scientists have studied the mechanism of alkali catalytic gasification of coal by steam, and the main research results include the electron‐transfer theory and oxygen‐migration theory . According to the relevant literature, the decomposition temperature of the ternary alkali carbonate salt is less than 900 °C, and the ternary eutectic salt in this experiment may undergo a series of reactions [Reactions (R8)–(R10)] . All of the intermediates (metallic E, E 2 O, E 2 CO 3 , and EOH) are catalytically active .…”

Section: Resultsmentioning

confidence: 99%

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Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Zhang

Ding

et al. 2016

Energy Tech

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The effect of a ternary eutectic salt (43.5 % Li2CO3–31.5 % Na2CO3–25 % K2CO3) on the CaSO4 oxygen carrier for chemical looping combustion (CLC) of coal char is experimentally investigated in a bench‐scale fluidized‐bed reactor with steam as the gasification agent at atmospheric pressure and 925 °C. The ternary eutectic catalyst is added to the CaSO4 oxygen carrier by physical mixing and impregnation, respectively. The enhanced carbon conversion and shortened reaction time in the fluidized bed reactor, coupled with the high weight loss rate of CaSO4 reduction with CO in the thermogravimetric analyzer (TGA), suggest that the reactions of coal char gasification and CaSO4 reduction are synergistically catalyzed in the presence of the ternary eutectic salt. The modified oxygen carriers prepared by physical mixing and impregnation show no significant difference in carbon conversion and gasification rates according to the experimental results. The sample with catalyst impregnated into the mixture of anhydrite and coal char gives higher activity compared to the samples with catalyst impregnated into the coal char or anhydrite solely, due to the more uniform distribution of the catalyst.

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Section: Resultsmentioning

confidence: 99%

“…Coal gasification catalyzed by alkali metal salts has been investigated by many scientists due to the fact that a small amount of alkali metal could significantly improve the coal gasification rate . As mentioned above, to accelerate the coal gasification, Gu et al .…”

Section: Introductionmentioning

confidence: 99%

Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Zhang

Ding

et al. 2016

Energy Tech

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“…Thus, a temperature located in the range of 700−850 °C was universally set as the catalytic gasification temperature. 8,15 The carbon conversion (X) and gasification rate (r) were calculated using the following equations:…”

Section: Methodsmentioning

confidence: 99%

Catalytic Gasification Activity of Na₂CO₃ and Comparison with K₂CO₃ for a High-Aluminum Coal Char

Wang

Huang

et al. 2015

Energy Fuels

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The catalytic performance of Na2CO3 for high-aluminum coal gasification was specially investigated, and the effect of the ash constituents in Sunjiahao (SJH) high-aluminum coal char on the catalytic activity of Na2CO3 and a comparison with that of K2CO3 were also studied through steam gasification experiments of SJH char catalyzed by Na2CO3 or K2CO3 carried out using a thermogravimetric analyzer and a fixed-bed reactor at 800 °C, respectively. The results indicate that the steam gasification rates of SJH char and acid-treated SJH char catalyzed by Na2CO3 are higher than those by K2CO3 with equal masses of catalyst. Na2CO3 can be used as the catalyst for high-aluminum coal gasification at 800 °C. The effect of the ash components on the catalytic activity of Na2CO3 is larger than that of K2CO3 in the catalytic steam gasification of SJH high-aluminum coal char at 800 °C. The X-ray diffraction (XRD) patterns of the steam gasification ashes of SJH char impregnated with Na2CO3 or K2CO3 reveal that the main composition is aluminosilicate, which is proved to have no catalytic activity. For catalytic steam gasification of acid-treated SJH char, the catalytic action of Na2CO3 is better because of the superior mobility and poor volatility of Na2CO3.

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“…The role of potassium‐based catalyst in coal‐steam gasification and the transformation characteristics of reduced‐state potassium during gasification have been studied. [ 140,141 ] Similar to coal gasification, the gasification performance of biochar is related to these factors. The impact of torrefaction on the structure of biochar has been discussed in the previous chapter.…”

Section: Gasification Of Torrefied Biomassmentioning

confidence: 99%

Integration of Biomass Torrefaction and Gasification based on Biomass Classification: A Review

Gong

Areeprasert

et al. 2021

Energy Tech

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Trace element migration and structure evolution are related to biomass gasification performance, which varies to a certain extent during torrefaction. This substantial summary of the integrated process based on biomass classification has practical significance for the consumption and commercialization of a bio‐refinery. Herein, biomass is divided into two categories and an understanding of the relevant variations is presented during the integrated two processes according to the classification. The effects of torrefaction on the organic (hemicellulose, cellulose, and lignin) and inorganic components (trace elements), and the physicochemical structural evolution (morphology, pore structure, functional groups) of biomass are reviewed. The differences (syngas generation and tar formation) between raw and torrefied biomass gasification are compared. Meanwhile, the effects of torrefaction on gasification performance and the possible gasification mechanisms are reviewed regarding pore structure, carbon structure, surface area, and alkali and alkaline earth metals (AAEMs). The gasification of the torrefied biomass materials on a pilot‐scale is outlined. Finally, future directions and technological challenges associated with the integrated technologies are proposed. More scaling‐up experiments should be conducted to investigate the mass and heat transfer in reactors during amplification and to improve the reactor's adaptability to biomass species in the contexts of economy and society.

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Transformation and Reactivity of a Potassium Catalyst during Coal–Steam Catalytic Pyrolysis and Gasification

Cited by 14 publications

References 15 publications

Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Catalytic Gasification Activity of Na₂CO₃ and Comparison with K₂CO₃ for a High-Aluminum Coal Char

Integration of Biomass Torrefaction and Gasification based on Biomass Classification: A Review

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Transformation and Reactivity of a Potassium Catalyst during Coal–Steam Catalytic Pyrolysis and Gasification

Cited by 14 publications

References 15 publications

Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Effect of Ternary Eutectic Salt on the Calcium Sulfate Oxygen Carrier for Chemical Looping Combustion of Coal Char

Catalytic Gasification Activity of Na2CO3 and Comparison with K2CO3 for a High-Aluminum Coal Char

Integration of Biomass Torrefaction and Gasification based on Biomass Classification: A Review

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Catalytic Gasification Activity of Na₂CO₃ and Comparison with K₂CO₃ for a High-Aluminum Coal Char