CONDITIONING OF A FEED STREAM FOR A FROTH SEPARATION VESSEL

摘要

A bitumen-containing froth is treated with a paraffinic solvent by adding the froth to the solvent in two or more additions prior to separation in a froth settling unit. The first addition of froth results in an S:B ratio which causes precipitation of asphaltenes in the bitumen. Maltenes are dissolved in the solvent. The dissolved maltenes shift the solubility parameter of the solvent. The second or more additions of the balance of the froth to the shifted solvent result in an overall S:B ratio resulting in precipitation of the asphaltenes and dissolving of the maltenes. The volumes of the two or more additions of froth can be adjusted to meet different objectives. Solvent requirements can be reduced, a target asphaltene content in the final product can be altered or both. Further, the target asphaltene content in the product can be designed so as not to foul downstream heating processes.