The Role of Supercritical Water on On-site Bitumen Upgrading System
Bibliographic record
Abstract
Abstract The role of supercritical water in upgrading bitumen is investigated by varying experimental parameters such as reaction pressure, which influences the density of water, and hydroxyl ions. Experiments were carried out using a batch reactor system operating with varying reaction pressure at a temperature of 703 K, and reaction time of 15 min. From the results such as the viscosity and the boiling point distribution of oil product etc., it can be seen that higher density supercritical water inhibits the cracking of bitumen to lower molecular weight substance. It has suggested that it is possible to obtain the product that has the desired quality in supercritical water on upgrading bitumen by adjusting reaction pressure. In the case of solvent with alkali it is found that alkali also helps to inhibit the cracking to lower molecular weight substances. Furthermore, the amount of the hydrogen became higher. It was inferred that some mechanism of hydrogen generation takes place with the addition of alkali. In experiments using a continuous flow reactor system at a temperature of 703 K, it was confirmed that higher density supercritical water also inhibits the pyrolysis. Introduction When oilsand in Canada is developed by SAGD (steam assisted gravity drainage) methods, it is necessary to combine these methods with on-site technologies for both visbreaking and upgrading. It is expected that supercritical water treatment of bitumen combined with SAGD is suitable for on-site upgrading technology because hot water can be used circularly. Supercritical water can prevent bitumen from coking unlike pyrolysis. It has been suggested that the supercritical water treatment of organic polymers such as polyethylene can generate lower molecular weight substances due to too much inhibition of pyroysis. Our previous studies have shown that bitumen could be cracked to lower molecular weight substances to remove sulfur in supercritical water with an alkali. However, the role of supercritical water as a solvent is not fully understood. The role of supercritical water in upgrading bitumen was therefore investigated by varying the experimental parameters, such as reaction pressure, that influence the density of water and hydroxyl ions in this study. Experimental Procedure Materials The bitumen used as test oil was produced by the SAGD method at Hangingstone, Alberta, Canada. Batch Reactor System The batch reactor (with an internal volume of 45 mL and composed of an internal wall of Hastelloy C) used in this study is shown schematically in Figure 1. This reactor has a highpressure valve for measuring pressure and collecting the produced gas. A typical experimental procedure was as follows: 5 g of bitumen, solvent, and a stirring ball were put into the reactor, which was then sealed. Water or KOH aqueous solution was used as the solvent. The experimental pressures were controlled by the volume of solvent. The reactor was placed in an induction furnace (Figure 2). The reactor temperature increased from room temperature at 40 K/min before becoming constant at the desired temperature. The reactor was shaken and agitated during the reaction.
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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".