Integrated process for deasphalting heavy oils using a gaseous antisolvent
AssigneeExxon Research & Engineering Co.
InventorThomas A. Davis
Life of this patent
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Abstract
The present invention relates to a process for the recovery of hydrocarbon oils from other heavier oils such as vacuum residua and, more particularly, to an improved process for deasphalting petroleum oils containing those asphalts. In one aspect of the invention, the process treats a solvent which has contacted the heavy oil with a gaseous antisolvent to separate effectively and usually without distillation, the solvent from the extracted oil. The deasphalted oil product typically will have low metals contaminants and enhanced MCR. Utilities or energy requirements for the process may be improved over prior art processes.
Claims20
A process for separating a liquid feedstream comprising a solvent selected from the group consisting of propane, butane, isobutane, pentane, isopentane, neopentane, hexane, 2-methyl pentane, 3-methyl pentane, 2-ethyl butane, heptane, 2-, 3-methyl hexane, or 3-ethyl pentane and a deasphalted oil containing aromatics and saturates comprising the steps of:
- introducing a sufficient amount of a gaseous expansion gas into said liquid feedstream to cause it to form an upper liquid phase and a lower phase comprising aromatics,
- separating the upper liquid phase from the lower liquid phase, and
- flashing said separated upper liquid phase to produce an expansion gas phase, a second upper liquid phase comprising solvent, and a second lower liquid phase comprising saturates.
The process of solvent deasphalting a heavy oil feedstock and recycling the solvent comprising the steps of:
- contacting the heavy oil feedstock with at least one solvent-containing stream to produce an extract stream containing solvent and deasphalted oil and a heavy stream containing heavy polar material,
- introducing a sufficient amount of a gaseous expansion gas into said extract stream to cause it to form a first upper liquid phase and a first lower liquid phase comprising solvents and aromatics,
- separating the first upper liquid phase from the first lower liquid phase and flashing it to produce an expansion gas phase, a second upper liquid phase comprising solvent, and a second lower liquid phase comprising saturates,
- separating the first lower liquid phase into a stream comprising aromatics and a stream comprising solvent for recycle to the extraction step,
- separating the second lower liquid phase into a stream comprising saturates and a stream comprising solvent for recycle to the extraction step,
- compressing the expansion gas phase for recycle to said extract stream.
Dependencies are inferred from the claim text.