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Fluidized bed hydrodynamic modeling of CO2 in syngas: Distorted RTD curves
  • Ariane Berard,
  • Bruno Blais,
  • Gregory Patience
Ariane Berard
Polytechnique Montreal

Corresponding Author:[email protected]

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Bruno Blais
Ecole Polytechnique de Montreal
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Gregory Patience
École Polytechnique de Montreal
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Bubbles rising through fluidized beds at velocities several times superficial velocities contribute to solids backmixing. In micro-fluidized beds, the walls constrain bubble sizes and velocities. To evaluate gas-phase hydrodynamics and identify diffusional contributions to longitudinal dispersion, we injected a mixture of H2, CH4, CO, and CO2 (syngas) as a bolus into a fluidized bed of porous fluid catalytic cracking catalyst while a mass-spectrometer monitored the effluent gas concentrations at 2 Hz. The CH4, CO, and CO2 trailing RTD traces were elongated versus H2 demonstrating a chromatographic effect. An axial dispersion model accounted for 92% of the variance in the data but including diffusional resistance between the bulk gas and catalyst pores and adsorption explained 98.6% of the variability. At 300 °C, the CO2 tailing disappeared consistent with expectations in chromatography (no adsorption). H2 and He are poor gas-phase tracers at ambient temperature. We recommend measuring the RTD at operating conditions.
13 Feb 2021Submitted to AIChE Journal
16 Feb 2021Submission Checks Completed
16 Feb 2021Assigned to Editor
17 Feb 2021Reviewer(s) Assigned
04 May 2021Editorial Decision: Revise Major
09 May 20211st Revision Received
12 May 2021Submission Checks Completed
12 May 2021Assigned to Editor
16 May 2021Reviewer(s) Assigned
14 Jun 2021Editorial Decision: Revise Minor
20 Jun 20212nd Revision Received
26 Jun 2021Submission Checks Completed
26 Jun 2021Assigned to Editor
11 Jul 2021Editorial Decision: Accept