Agglomerate formation is a common phenomenon that can cause operating problems in the fluid coking reactor. When agglomerates form they provide longer diffusion paths of the reaction products through the liquid layers and liquid bridges within the agglomerate, which leads to higher mass transfer resistance, trapping of the reaction products and increasing the undesired coke formation reactions. Surviving agglomerates in the reactor can also cause fouling of the reactor interior and defluidization of the bed. The ultimate coke yield was determined for agglomerates of Athabasca vacuum residue and solid particles by heating on Curie-point alloy strips in an induction furnace at 503 oC and 530 oC and in a fluidized bed reactor at 500 oC until all toluene-soluble material was converted. Coke yields from agglomerates were compared to the results from reacting thin films of vacuum residue. The average coke yield from the agglomerates was 23%, while the coke yield from thin films of 20 m thickness was 11%, which supports the role of mass transfer in coke formation reactions. The ultimate coke yield was insensitive to vacuum residue concentration, agglomerate size, reaction temperature and agglomerate disintegration.
The temperature profile within agglomerates was measured by implanting a thermocouple at the agglomerate center, and a heat transfer model was used to describe the temperature variation with time. The effective thermal diffusivity of the agglomerates was 0.20 x 10-6 m2/s. Control experiments on reactions in thin liquid films confirmed that heating rates in the range of 14.8 to 148 K/s had no effect on the ultimate yield of coke
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1461 |
| Date | 11 1900 |
| Creators | Ali, Mohamed Ali Hassan |
| Contributors | Gray, Murray (Chemical and Materials Engineering), Gray, Murray (Chemical and Materials Engineering), McCaffrey, William (Chemical and Materials Engineering), Ben-Zvi, Amos (Chemical and Materials Engineering), Fleck, Brian (Mechanical Engineering), Mahinpey, Nader (Department of Chemical and Petroleum Engineering, University of Calgary), McMillan, Jennifer (Syncrude Canada Ltd.) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 2801354 bytes, application/pdf |
| Relation | Ali, M; Courtney, M.; Boddez, L.; Gray, M., Can J Chem Eng, 2010, v 88, issue 1, 48-54 |
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