CoMo and NiMo catalyst stacking for renewable diesel

摘要

Methods are provided herein for co-processing of biocomponent feeds as well processing of mineral feeds in a reaction system at hydrogen partial pressures of about 500 psig (3.4 MPag) or less. The methods include using stacked beds of both CoMo and NiMo catalysts. The stacked catalyst beds provided unexpectedly high catalyst activity as the input feed to a reaction system was switched between a mineral feed and a feed containing both mineral and biocomponent portions. Additionally, use of stacked catalyst beds can allow for maintenance of the activity for the catalyst system in a reaction system while still achieving a desired activity for both types of feeds.

主权项

1. A method for hydroprocessing sulfur-containing feeds, comprising:
exposing a first feedstock comprising a first mineral fraction and a bio-derived fraction to a first supported catalyst comprising a first Group VI metal and a Group VIII metal selected from Co or Ni under first effective hydrodesulfurization conditions, the first effective hydrodesulfurization conditions including a hydrogen partial pressure of about 500 psig (3.4 MPag) or less, to form a first effluent, the first feedstock comprising at least about 0.5 wt % of oxygen, at least about 800 wppm of sulfur, and from 1 wt % to 35 wt % of the bio-derived fraction; exposing the first effluent to a second supported catalyst comprising a second Group VI metal and a Group VIII metal selected from Co or Ni, in the presence of hydrogen under the first effective hydrodesulfurization conditions to form a first desulfurized product having a sulfur content of about 200 wppm or less, the selected Group VIII metal in the second catalyst being different from the selected Group VIII metal in the first catalyst; exposing a second feedstock comprising a second mineral fraction to at least a portion of the first supported catalyst in the presence of hydrogen under second effective hydrodesulfurization conditions to form a second effluent, the second effective hydrodesulfurization conditions including a hydrogen partial pressure of about 500 psig (3.4 MPag) or less, the second feedstock containing less than about 0.5 wt % of a bio-derived fraction and having a sulfur content of at least about 800 wppm, the at least a portion of the first supported catalyst comprising at least about 80 vol % of the first supported catalyst that was exposed to the first feedstock; and exposing the second effluent to at least a portion of the second supported catalyst in the presence of hydrogen under the second effective hydrodesulfurization conditions for forming a second desulfurized product having a sulfur content of about 200 wppm or less, the at least a portion of the second supported catalyst comprising at least about 80 vol % of the second supported catalyst that was exposed to the first feedstock, wherein the first supported catalyst and the second supported catalyst form a stacked bed of catalysts.