Rapid and continuous synthesis of methacrolein with high selectivity by condensation of propanal with formaldehyde in laboratory
Bibliographic record
Abstract
Abstract An experimental device with a micro‐tubular reactor for continuous reaction process was designed and constructed based on the reaction mechanisms and characteristics of condensation of propanal with formaldehyde, a short mean residence time (a few seconds) for the reactive mixture was acquired to increase selectivity to methacrolein (MAL) by reducing the side reactions. Diethylamine and acetic acid aqueous solution was used as catalysts for the reaction. The reactor temperature ranged between 100 and 210 °C. The reactor pressure was set at 4.5–6.0 MPa to make sure that the reaction can be carried out in liquid phase. The results indicated that the reaction rate was heavily influenced by the concentration of the catalysts and the feed preheating temperature. When the feed preheating temperature was about 132 °C, the mass concentration of diethylamine was about 6 %, the reaction pressure was 4.5–5.0 MPa, and the mean residence time varied from 4.5 to 5.5 s, high conversion of propanal (99.9 %) and high selectivity to MAL (98.7 %) were acquired. High catalytic activity and high selectivity were maintained after the catalysts had been recycled six times.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".