Fluidized bed hydrodynamic modeling of <scp>CO<sub>2</sub></scp> in syngas: Distorted <scp>RTD</scp> curves due to adsorption on <scp>FCC</scp>
Bibliographic record
Abstract
Abstract 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 H 2 , CH 4 , CO, and CO 2 (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 CH 4 , CO, and CO 2 trailing RTD traces were elongated versus H 2 demonstrating a chromatographic effect. An axial dispersion model accounted for 92% of the variance but including diffusional resistance between the bulk gas and catalyst pores and adsorption explained 98.6% of the variability. At 300°C, the CO 2 tailing disappeared consistent with expectations in chromatography (no adsorption). H 2 and He are poor gas‐phase tracers at ambient temperature. We recommend measuring RTD at operating conditions.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".