| 摘要 |
<p>Dewaxing aids used to facilitate the separation of waxes from waxy hydrocarbon oils in solvent dewaxing processes are recovered from the solvent free separated wax (1) by means of an ultrafiltration process employing a selective membrane (in 2A, 2B, 2C, 2D and 5A, 5B, 5C) selected from polysulfone, nylon and cellulose acetate, preferably polysulfone, under specific conditions of temperature, pressure and flow velocity. The selective membrane is preferably used in the form of a spiral wound element which employs a feed/retentate spacer made of a specific polyester material to enhance mixing and reduce pressure drop in the element.</p> |
