| 主权项 |
1. A process for upgrading of heavy oils comprising the steps of:
feeding a heavy oil feed stream to a hydrodemetalization reaction vessel, the hydrodemetalization reaction vessel containing a hydrodemetalization catalyst, the hydrodemetalization catalyst being operable to remove a substantial quantity of metal compounds from the heavy oil feed stream; feeding a hydrogen source to the hydrodemetalization reaction vessel, the hydrogen source having a hydrogen pressure in the range of 50 to 150 bar; and feeding a light hydrocarbon diluent to the hydrodemetalization reaction vessel, the light hydrocarbon diluent being substantially in liquid phase, wherein the feeding of the heavy oil feed stream and the hydrogen source and the light hydrocarbon diluent to the hydrodemetalization reaction vessel defines a feed rate, the feed rate further defining a total liquid hourly space velocity within a predetermined liquid hourly space velocity range of 0.1 hr−1 to 5 hr−1 such that a combined effluent stream is produced and removed from the hydrodemetalization reaction vessel; the process further comprising; feeding the combined effluent stream to a hydrodesulfurization reaction vessel, the hydrodesulfurization reaction vessel containing a hydrodesulfurization catalyst operable to remove a substantial amount of sulfur from the combined effluent such that a hydrodesulfurization catalyst effluent is produced; feeding the hydrodesulfurization catalyst effluent to a hydroconversion reaction vessel, the hydroconversion reaction vessel containing a hydroconversion catalyst, the hydroconversion catalyst being operable to convert the hydrodesulfurization catalyst effluent to a hydroconverted product, the hydroconverted product having, an increased API gravity as compared to the heavy oil feed stream; feeding the hydroconverted product to a separation unit, the separation unit operable to separate the hydroconverted product into a process gas component stream and a liquid product; feeding the liquid product to a flash vessel to separate a light hydrocarbon fraction and a final liquid product, the final liquid product having a reduced sulfur content, reduced metal content and increased API gravity in comparison to the heavy oil feed stream; recycling at least a portion of the light hydrocarbon fraction to the hydrodemetalization reaction vessel; and combining the recycled light hydrocarbon fraction with a fresh light hydrocarbon diluent to form the light hydrocarbon diluent and to thereby recycle the light hydrocarbon diluent to the hydrodemetalization reaction vessel to reduce coke formation. |
