| 摘要 |
Asphaltenes and ash-forming constituents are removed from a residual petroleum oil fraction by precipitating these constituents with a hydrocarbon with 4 to 9 carbon atoms in the molecule, with or without substituted polar groups, and having a surface tension with respect to air of less than 24 dynes/an (at 25 DEG C.), and completely or partially separating the precipitated constituents from the oil by passing the mixture through one or more hydrocyclones and/or multicyclones. Suitable precipitants include paraffins such as pentane, hexane, heptane, and iso-octane, methyl cyclohexane, dimethyl cyclopentane, diethyl ether, ethyl acetate, and mixtures thereof. Technical mixtures, especially those which contain pentane, such as are obtained in the straight run distillation of crude oil, may be used. The oil phase and/or the asphaltene suspension phase may be passed through further cyclones, further precipitant being added to the asphaltene suspension if desired. Specification 634,135 is referred to. |
