| 摘要 |
<p>This invention relates to a method for ultrafiltering heavy hydrocarbons containing detrimental qualities of metals and CCR, said method comprising feeding the heavy hydrocarbons to a first ultrafiltration stage wherein the feed is contacted with an ultrafiltration membrane thereby producing a first permeate and a first retentate and feeding the first permeate to a second ultrafiltration stage wherein the first permeate is contacted with an ultrafiltration membrane which is the same as the ultrafiltration membrane in the first ultrafiltration stage to recover a second permeate of significantly reduced metals and CCR content and a second retentate. The second permeate can be sent to subsequent ultrafiltration stages utilizing the same membrane with permeate from each such stage being used as feed to the next subsequent downstream stage. Retentate from the different stages can be recycled to the feed of the previous upstage ultrafiltration stage or can be combined with the retentate streams from the various ultrafiltration stages.</p> |
