The effect of mineral matter and pyrolysis conditions on the gasification of Greek lignite by carbon dioxide

Samaras, P.; Diamadopoulos, Evan; Sakellaropoulos, G.P.

doi:10.1016/0016-2361(96)00058-0

Cited by 72 publications

(42 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A better understanding of associated atomistic reaction mechanism may facilitate improvements in the evaluation of coal char gasification kinetics, including rates and efficiencies. Rates of gasification of porous carbons are affected by parameters such as active site concentration, accessibility of the reactant gas into the internal area of the char, and presence of active catalysts that mediate in reactions with gasification agents [24,[29][30][31][32][33][34][35][36][37].…”

Section: Tpd Transient Kinetics As Well As Other Characterisation Tmentioning

confidence: 99%

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Roberts

Everson

Domazetis

et al. 2015

Carbon

View full text Add to dashboard Cite

Experimental measurements and DFT atomistic modelling were conducted to elucidate the mechanisms for gasification chemistry of char with CO2 gas. The molecular models used were based on experimental representations of coal chars derived from the vitrinite-and inertinite-rich South African coals at 1000 . The HRTEM and XRD techniques were used to construct parallelogram-shaped PAH stacks of highest frequency in the vitrinite-rich (7x7) and intertinite-rich (11x11) char structures. Computations were executed to get the nucleophillic Fukui functions, at DFT-DNP level, to elucidate the nature and proportions of carbon active sites and quantify their reactivity. The DFT-DNP-computed reaction pathways and transition states, to obtain the energy of reaction and activation energies for the gasification reactions of CO2 with active carbon sites were examined. These results were compared with TGA experimental results at 900-980 . The mean nucleophillic Fukui function of the H-terminated char models and active sites located at similar edge positions

show abstract

Section: Tpd Transient Kinetics As Well As Other Characterisation Tmentioning

confidence: 99%

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Roberts

Everson

Domazetis

et al. 2015

Carbon

View full text Add to dashboard Cite

show abstract

“…The selection of the pretreatment processes is based on reported literatures, wherein, leaching of biomass [14,15] and coal/carbon deashing [16,17] processes have been elaborated. The pretreatment processes are aimed at maximum extraction of ash.…”

Section: Deashing Treatmentsmentioning

confidence: 99%

Influence of pretreatment for deashing of sugarcane bagasse on pyrolysis products

Das

Ganesh²,

Wangikar³

2004

Biomass and Bioenergy

223

111

View full text Add to dashboard Cite

“…For char-CO 2 gasification in a TGA, at 700-900 o C, it was found that gasification rates of chars with high ash content were higher than those of similarly prepared char with low ash content, due to the presence of catalytically active inorganic constituents, and the gasification rate increased with CO 2 concentration in the reaction gases. The effects of heating rate and CO 2 concentration on char gasification rate were more pronounced for samples from untreated lignite than for those from acid-washed lignite [3]. While in a single-particle reactor at 714-892 o C, it was found that gasification rate was independent of particle size, suggesting that the gasification rate follows the homogeneous model.…”

Section: Introductionmentioning

confidence: 86%

“…Low-rank coals generally have higher but widely spread reactivities than high-rank coals, due to the high concentration of active oxygen-containing functional groups, high proportion of transitional and macropores, and high dispersion of catalytic inorganic constituents [1]. In addition to coal properties, pyrolysis temperature [3][4][5][6] and structural properties of char and their variation during pyrolysis also have significant effects on coal gasification reactivity [4,[7][8][9]. Following pyrolysis, coal char undergoes either combustion or gasification.…”

Section: Introductionmentioning

confidence: 99%

CO2 gasification of Thai coal chars: Kinetics and reactivity studies

Sawettaporn

Bunyakiat

Kitiyanan

2009

Korean J. Chem. Eng.

View full text Add to dashboard Cite

Two sized fractions (<75 µm and 150-250 µm) of Ban Pu lignite A and Lampang subbituminous B coals were pyrolyzed in a drop tube fixed bed reactor under nitrogen atmosphere at 500-900 o C. Gasification of coal chars with excess carbon dioxide was then performed at 900-1,100 o C. The result was analyzed in terms of reactivity index, reaction rate and activation energy. It was found that chars at lower pyrolysis temperature had highest carbon conversion, and for chars of the same sized fraction and at the same pyrolysis temperature, reactivity indices increased with gasification temperature. The lower rank Ban Pu lignite A had higher R s values than higher rank Lampang subbituminous B coals. Smaller chars from both coals had higher R s values, due to the higher ash content. At present, it can be concluded that, within the gasification temperature range studied, gasification rates of chars obtained at various pyrolysis temperatures showed a linear correlation with temperature. However, additional experiment is needed to verify the correlation.

show abstract

The effect of mineral matter and pyrolysis conditions on the gasification of Greek lignite by carbon dioxide

Cited by 72 publications

References 26 publications

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Density functional theory molecular modelling and experimental particle kinetics for CO2–char gasification

Influence of pretreatment for deashing of sugarcane bagasse on pyrolysis products

CO2 gasification of Thai coal chars: Kinetics and reactivity studies

Contact Info

Product

Resources

About