Isothermal Gasification of in Situ/ex Situ Coal Char with CO2 in a Micro Fluidized Bed Reaction Analyzer

Wang, Fang; Zeng, Xi; Shao, Ruyi; Wang, Yonggang; Yu, Jian; Xu, Guangwen

doi:10.1021/acs.energyfuels.5b00676

Cited by 35 publications

(14 citation statements)

References 33 publications

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“…As can be seen from the figure, the final equilibrium mass and time are found to be dependent on temperature. The reaction rate is shown to be faster at higher temperatures for both biomass samples [61]. Note that above 550 °C the equilibrium condition mass of ARTOK was always lower than the AROK, since the oxidation of carbon in the char takes place parallel to thermal decomposition and release of volatile matter [62].…”

Section: Kinetic Parametersmentioning

confidence: 88%

Kinetics and Performance of Raw and Torrefied Biomass in a Continuous Bubbling Fluidized Bed Gasifier

Al-Farraji

Marsh

Steer

et al. 2017

Waste Biomass Valor

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This paper is an experimental study of the kinetics of gasification of olive kernel by using a thermogravimetric fluidized bed reactor technique. Gasification of 'as received' and torrefied olive kernels were investigated in a lab-scale bubbling fluidized bed gasifier, operating at up to 3.2 kg/h. The effect of bed temperature between 550 and 750 °C in 50 °C increments on the gasification product gas at mass-based equivalence ratios of 0.15 and 0.2 was studied. To explore the potential of torrefied biomass, the gasification results were compared to that of the 'as received' biomass. The product gas from torrefied biomass produced higher H 2 , CO and CH 4 concentrations at identical oxidant flow rates in addition to higher cold gas efficiency and higher product gas heating value. The influence of equivalence ratio in gasification was also investigated at reactor temperatures of 750 °C and five equivalence ratios (0.15, 0.2, 0.25, 0.3, and 0.35). The results revealed that the torrefied biomass has the highest HHV at an equivalence ratio of 0.2 with a value of 6.09 MJ/Nm 3 , while 'as received' biomass 4.72 MJ/Nm 3 . Kinetic experiments under isothermal conditions were performed for the gasification of the materials in continuous mode. A mass balance model was successfully used to provide the capability of separately determining the rate constant of the reactions taking place. The kinetic parameters were calculated by a first order reaction model giving activation energies for 'as received' olive kernels of 84 kJ/mol and for torrefied olive kernels of 106 kJ/mol.

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Section: Kinetic Parametersmentioning

confidence: 88%

Kinetics and Performance of Raw and Torrefied Biomass in a Continuous Bubbling Fluidized Bed Gasifier

Al-Farraji

Marsh

Steer

et al. 2017

Waste Biomass Valor

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“…In recent years, micro-fluidized bed (MFB) has attracted more attention due to its fast screening and process-intensifying properties [4,5]. Therefore, MFB has been applied to different areas such as solid processing [6,7], chemical conversions [8][9][10], CO 2 capture [11], wastewater treatment [12,13], bioproduction [14,15], etc.…”

Section: Introductionmentioning

confidence: 99%

Design and Investigation of a 3D-Printed Micro-Fluidized Bed

Zhang

Goh

et al. 2021

ChemEngineering

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Micro-fluidized bed has aroused much attention due to its low-cost, intensified-process and fast-screening properties. In this paper, a micro-fluidized bed (15 × 15 mm in cross-section) was designed and fabricated with the use of the stereolithography printing technique, for the investigation of bubbles’ hydrodynamics and comparison of the solids (3D-printed particles VS fungal pellets) fluidization characteristics. In a liquid–gas system, bubble flow regime started from mono-dispersed homogeneous regime, followed by poly-dispersed homogeneous regime, transition bubble regime and heterogeneous bubble regime with increasing gas flowrates from 3.7 mL/min to 32.7 mL/min. The impacts from operating parameters such as gas flowrate, superficial liquid velocity and gas sparger size on bubble size, velocity and volume fraction have been summarized. In liquid–solid fluidization, different solid fluidization regimes for both particles bed and pellets bed were identified. From the bed expansion results, much higher Umf of 7.8 mm/s from pellets fluidization was observed compared that of 2.3 mm/s in particles fluidization, because the hyphal structures of fungal pellets increased surface friction but also tended to agglomerate. The similar R–Z exponent n (5.7 and 5.5 for pellets and particles, respectively) between pellets and particles was explained by the same solid diameter, but much higher Ut of 436 µm/s in particles bed than that of 196 µm/s in pellets bed is a consequence of the higher density of solid particles. This paper gives insights on the development of MFB and its potential in solid processing.

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“…In comparison to TGA, the MFBRA features: (1) high rates of heat and mass transfer, (2) capability of online instantaneously pulse feeding and super‐fast heating of powder reactant to bed temperature, (3) negligible external diffusion inhibition, and (4) fast on‐line measurement 19,20 . Until now, it has been successfully applied to study the mechanisms and kinetics of a variety of gas–solid reactions, including pyrolysis, 22–24 gasification, 14,25,26 combustion 27,28 of coal, biomass, oil shale and chars, calcination, 11,20 and reduction 29–32 of various materials as well as catalytic gas–solid reactions, 33,34 etc. These applications have demonstrated that MFBRA is effective, reliable, and adaptable to various gas–solids reactions.…”

Section: Introductionmentioning

confidence: 99%

Acquiring real kinetics of reactions in the inhibitory atmosphere containing product gases using micro fluidized bed

et al. 2021

Self Cite

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This study proposed an isotope‐tagging method to investigate reactions under the atmosphere of product gas. To illustrate this method, the calcination kinetics of calcium carbonate Ca13CO3 in CO2 atmospheres were investigated by monitoring 13CO2 produced using a micro fluidized bed reaction analyzer (MFBRA). The results demonstrated that the presence of CO2 in reaction atmosphere increases the apparent activation energy. The increase in the apparent activation energy is, however, significantly overestimated by the thermogravimetric analyzer (TGA) because of the excessive suppression by stagnated product gas inside the sample crucible. Comparatively, the apparent activation energy increases with CO2 from the MFBRA due primarily to the thermal equilibrium limitation, because the gas diffusion in the MFBRA is essentially eliminated. It is thus concluded that the MFBRA is quite capable of acquiring the real kinetics of reactions in such inhibitory atmospheres.

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Isothermal Gasification of in Situ/ex Situ Coal Char with CO₂ in a Micro Fluidized Bed Reaction Analyzer

Cited by 35 publications

References 33 publications

Kinetics and Performance of Raw and Torrefied Biomass in a Continuous Bubbling Fluidized Bed Gasifier

Kinetics and Performance of Raw and Torrefied Biomass in a Continuous Bubbling Fluidized Bed Gasifier

Design and Investigation of a 3D-Printed Micro-Fluidized Bed

Acquiring real kinetics of reactions in the inhibitory atmosphere containing product gases using micro fluidized bed

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