| 摘要 |
In a process for preparing a synthetic bitumen fron a residual oil, a precipitant is added to the residual oil to precipitate asphaltenes from the oil, the separated asphaltenes are added to a further quantity of residual oil and the mixture is partially distilled, the synthetic bitumen being the bottom product. The residual oil may have an initial boiling point of at least 300 DEG C. and the preferred precipitant is pentane used in a proportion of between 4.5 and 8.5 parts by volume of precipitant to one part by volume of oil. The precipitation may be effected at a temperature between 30 DEG and 80 DEG C. and the asphaltenes are separated, after from 0.3 to 10 minutes in a mixer, in one or more hydrocyclones. The precipitation may be carried out in two stages, each stage being followed by a separation in a hydrocyclone. The asphaltene concentrate from the second hydrocyclone may be further concentrated by being mixed with a portion of the heated mixture of asphaltenes and residual oil about to be distilled to yield the synthetic bitumen. A deasphaltenized oil and the precipitant are recovered by distillation of the mixture obtained during separation of the asphaltenes and the top product of the distillation of the asphaltenes and residual oil mixture is an asphaltene free oil. |
