| 摘要 |
A flexible once-through process for hydroprocessing heavy oil feedstock is disclosed. The process employs a plurality of contacting zones and at least a separation zone to convert at least a portion of the heavy oil feedstock to lower boiling hydrocarbons, forming upgraded products. The contacting zones operate under hydrocracking conditions, employing a slurry catalyst which comprises an active metal catalyst having an average particle size of at least 1 micron in a hydrocarbon oil diluent, at a concentration of greater than 500 wppm of active metal catalyst to heavy oil feedstock. The plurality of contacting zones and separation zones are configured in a permutable fashion allowing the once-through process to be flexible operating in various modes: a sequential mode; a parallel mode; a combination of parallel and sequential mode; all online; some online and some on stand-by; some online and some off-line; a parallel mode with the effluent stream from the contacting zone being sent to at least a separation zone in series with the contacting zone; a parallel mode with the effluent stream from the contacting zone being combined with an effluent stream from at least another contacting zone and sent to the separation zone; and combinations thereof. In one embodiment, the effluent from a contacting zone is sent to the next contacting zone in series for further upgrade, with the next contacting zone having a pressure drop of at most 100 psi, with the pressure drop is not due to a pressure reducing device as in the prior art. In one embodiment, at least an additive material selected from inhibitor additives, anti-foam agents, stabilizers, metal scavengers, metal contaminant removers, metal passivators, and sacrificial materials, in an amount of less than 1 wt. % of the heavy oil feedstock, is added to at least one of the contacting zones. |
