Na2CO3 catalyzed CO2 gasification of coal char and its intermediate complexes

Liu, Yun; Guan, Yao; Zhang, Kai

doi:10.1007/s11164-018-3586-7

Cited by 19 publications

(4 citation statements)

References 53 publications

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“…greater Na 2 CO 3 mass loss is observed in a reducing atmosphere (presence of CO) vs an inert atmosphere (argon purge). Liu et al [26] . studied the mass loss of graphite in the presence of Na 2 CO 3 , where C−Na 2 O, Na, CO and CO 2 products can form between 710–950 °C.…”

Section: Resultsmentioning

confidence: 99%

“…According to Su et al [25] greater Na 2 CO 3 mass loss is observed in a reducing atmosphere (presence of CO) vs an inert atmosphere (argon purge). Liu et al [26] studied the mass loss of graphite in the presence of Na 2 CO 3 , where CÀ Na 2 O, Na, CO and CO 2 products can form between 710-950 °C. As FactSage equilibrium predictions showed a very small amount of Na in the gas phase above 0.5 X TiO 2 (< 2.5 mol% for the reducing atmosphere), the TiO 2 in the melt likely stabilizes the Na 2 O resulting in less additional mass loss at higher X TiO 2 .…”

Section: Bulk Electrolysismentioning

confidence: 99%

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Evaluating Phase Relations in Molten Oxides for Electrochemical Operating Windows for Selective Metal Reduction

Ford,

Newport,

Marshall

et al. 2024

ChemElectroChem

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Molten oxide electrolysis is a promising pathway to decarbonize primary metal production. The oxide electrolyte is less hazardous and eco‐toxic than halides (molten salt electrolysis) and, with the use of renewably generated electricity and an inert anode, oxygen is produced as a by‐product instead of CO2. Building fundamental understanding of electrolytic operating windows requires starting with simple chemistries. Here we investigate a simplified binary oxide system as an electrolyte for titanium oxide reduction to metal. The TiO2−Na2O binary system forms a eutectic, reducing the liquidus temperature over a wide composition range. FactSage 8.1 predictions suggested Ti reduction would become favorable over Na reduction for compositions greater than 0.49 mole fraction TiO2. The prediction was validated by the detection of metallic Ti after electrolysis experiments. However, the reduction efficiency was too low (0.24±0.08 % at −0.1 V vs Ti reference electrode) for the TiO2−Na2O system to be a viable industrial electrolyte for Ti production. Scoping for other binary oxide systems was performed for electrolytic production of two critical metals, tantalum and neodymium. Based on TiO2−Na2O system's predicted behavior, candidate binary oxide systems were identified that contained congruently melting line compounds flanked by eutectic reactions from the ACerS‐NIST Phase Equilibria diagrams database.

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Section: Resultsmentioning

confidence: 99%

Section: Bulk Electrolysismentioning

confidence: 99%

Evaluating Phase Relations in Molten Oxides for Electrochemical Operating Windows for Selective Metal Reduction

Ford,

Newport,

Marshall

et al. 2024

ChemElectroChem

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“…Liu et al [12] found that during CO 2 gasi cation, the decrease of Ca dispersion would decrease the catalytic activity of Ca. Liu et al [13] reported that during CO 2 gasi cation, the addition of NaCO 3 would promote the formation of sodium-oxygen complexes, which can improve the gasi cation reactivity of char. At present, catalysts for char reactivity studies are mostly in the form of additives, such as the AAEM species of carbonates, halides, and other compounds.…”

Section: Introductionmentioning

confidence: 99%

Variation of char reactivity during catalytic gasification with CO2 : comparison among catalytic gasification by ion-exchangeable Na, Ca, and Na/Ca mixture

Chen

Zhang

Xing

et al. 2022

Preprint

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Reactivity is an important indicator to evaluate the gasification performance, and it is also the key to design and optimize the gasification process. The type and activity of the catalyst have great impacts on the gasification reactivity of the char. In this study, the catalytic behavior of ion-exchangeable Na and Ca during CO2 gasification process and the influence mechanism of ion-exchangeable Na and Ca on the gasification reactivity of coal char were researched. The results indicated that the reactivity of Ca-Char was greater than that of Na-Char. The inactivation of Ca was mainly due to the loss and the dispersion deterioration of Ca. The increase of CO2 concentration can not only significantly increase the catalytic activity of Na and Ca, but also enhance the sustainability of Na catalytic activity. The interaction between Na and Ca had inhibition effects on the reactivity of char during CO2 gasification. The higher the ratio of Ca-Char, the more significant the inhibition effects.

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“…Catalysts with lithium and potassium alkali metals are the most effective among the simple catalysts because they efficiently promote coal gasification. , However, potassium and sodium evaporate during high-temperature gasification, making it difficult to maintain catalytic performance. Alkaline earth metals such as calcium or group VIII metals are commonly utilized, − and their performance can be maintained in gasified char. However, their catalytic activity is considerably lower than the activity of catalysts with alkali metals. , Obviously, single catalysts cannot meet the catalytic demands of the gasification process (i.e., high reactivity, stability toward deactivation, and selectivity) due to the complexity of the process.…”

Section: Introductionmentioning

confidence: 99%

Study of Electrochemical Catalytic Coal Gasification: Gasification Characteristics and Char Structure Evolution

Yang

Duan

et al. 2021

ACS Omega

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Electrochemical catalytic coal gasification experiments with Fuxin (FX) coal under a CO 2 atmosphere were conducted to evaluate the effects of power and temperature on coal gasification and char structure evolution during electrochemical catalytic gasification (ECG). When the power was 400 W, with temperature increasing from 800 to 1000 °C, the CO content in the gas products increased by 8.16%, the H 2 content increased by 8.39%, and the CH 4 concentration in the gas products initially increased and then decreased. When the temperature is 900 °C, with power increasing from 0 to 400 W, the CO content in the gas products increased by 58.27%, the H 2 content increased by 81.33%, and the CH 4 concentration in the gas products increased from 1.31 to 2.37%. The gasification reactivity and the concentration of combustible gas generated during ECG were higher than those during common coal gasification. Thermal electrons play important roles in ECG. These electrons could promote ring opening reactions and aromatic compound cracking and inhibit aromatization reactions while increasing the number of oxygen-containing functional groups in char, consequently enhancing the char gasification reactivity.

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Na2CO3 catalyzed CO2 gasification of coal char and its intermediate complexes

Cited by 19 publications

References 53 publications

Evaluating Phase Relations in Molten Oxides for Electrochemical Operating Windows for Selective Metal Reduction

Evaluating Phase Relations in Molten Oxides for Electrochemical Operating Windows for Selective Metal Reduction

Variation of char reactivity during catalytic gasification with CO2 : comparison among catalytic gasification by ion-exchangeable Na, Ca, and Na/Ca mixture

Study of Electrochemical Catalytic Coal Gasification: Gasification Characteristics and Char Structure Evolution

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