Characterization of Acid-Soluble Oxidized Asphaltenes by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry: Insights on Oxycracking Processes and Asphaltene Structural Features
Bibliographic record
Abstract
The dissolution of organic matter into water via oxidative processes, named oxycracking, has been practiced for a long time for the removal of organic pollutants, in which oxygen induces breakage and functionalization of organic molecules. Recently, oxycracking has been explored as an alternative approach to handling the increased amount of solid residues produced in oil sands upgrading activities that involve carbon rejection in solvent deasphalting units. This study uses an asphaltene-rich feedstock, operationally known as petroleum pitch, isolated from an Athabasca bitumen vacuum residue, which was submitted to oxycracking reactions at 200 and 220 °C. The feed and water-soluble fractions isolated at pH 1, termed acid-soluble oxidized asphaltenes (ASOA), were analyzed by ultrahigh-resolution mass spectrometry [Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS)] using electrospray and atmospheric pressure photoionization ion sources. FTICR-MS analysis revealed extensive oxidation of all compound classes originally present in the asphaltene-rich feed. Double bond equivalent (DBE) distribution plots show that sequential carboxylation (formation of a carboxyl group) occurs progressively with an increasing reaction temperature, leading to the incorporation of up to 15 oxygen atoms per molecule, whereas simultaneous decarboxylation reactions produce a CO 2 -rich gas phase. ASOA samples also show lower overall carbon number distributions than the asphaltene feed, which is direct evidence of C–C bond cleavage during the oxycracking process. In addition, molecular fragments detected in ASOA after carbon–carbon bond cleavages showed not only lower carbon numbers but also lower DBEs per molecule, consistent with a more dominant archipelago architecture for the parent asphaltene molecules.
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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".