1D NMR Analysis of a Quaternary MEA–DEAB–CO<sub>2</sub>–H<sub>2</sub>O Amine System: Liquid Phase Speciation and Vapor–Liquid Equilibria at CO<sub>2</sub> Absorption and Solvent Regeneration Conditions
Bibliographic record
Abstract
New procedures were developed for our recently developed 1D NMR calibration method for quantitative liquid phase speciation analysis of a complex quaternary CO 2 loaded blended amine solution such as MEA–DEAB–CO 2 –H 2 O at high and low temperatures respectively representing CO 2 stripping and absorption conditions. The ion speciation analyses were performed in conjunction with the corresponding vapor–liquid equilibrium (VLE) of the system to enable the estimation of possible CO 2 capture performance. Accurate speciations were performed for a quaternary amine system using four concentrations consisting of 5.0 M MEA blended with 0.5, 1.0, 1.5, and 1.25 M DEAB solutions with different CO 2 loadings at 24 °C, and for the first time, at higher temperatures using only the NMR calibration method. By comparison, the NMR calibration method with the new procedures was shown to be valid and perhaps the only approach for determining ion speciation for quaternary amine solutions at higher temperatures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".