| 摘要 |
<p>To reduce the benzene content of a hydrocarbon mixture that contains benzene and other hydrocarbons, the mixture is fed to a distillation column so as to separate an overhead distillate, a bottom residue, and a sidestream having a benzene content richer than in the distillate and in the residue; the resultant sidestream is sent to at least one permeation zone to permeate the benzene selectively and retain a retentate having a reduced content of benzene; and at least part of the retentate is recycled to at least one level in the distillation column, preferably two levels, one at above and one below the feedpoint to the column. The permeate benzene stream is optionally subjected to extractive distillation in order to increase the purity of the resultant benzene.</p> |
