Sequential slurry hydroconversion of heavy oils
AssigneeExxonMobil Research and Engineering Company
InventorsRamanathan Sundararaman, Thomas Francis Degnan, JR., Rustom Merwan Billimoria, Randolph J. Smiley
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Abstract
Systems and methods are provided for sequential slurry hydroconversion of heavy oil feedstocks. One or more low pressure slurry hydroconversion stages can be used to perform a majority of the conversion of a heavy oil feedstock. The bottoms from the low pressure stages can then be slurry hydroconverted in one or more high pressure stages to further convert the feedstock.
Claims20
A method for processing a heavy oil feedstock, comprising:
- providing a heavy oil feedstock having a 10% distillation point of at least about 650° F. (343° C.);
- exposing the heavy oil feedstock to a catalyst under first effective slurry hydroconversion conditions to form an effluent comprising at least a plurality of liquid products and a bottoms product, the first effective slurry hydroconversion conditions comprising a hydrogen partial pressure of about 1500 psig (10.3 MPag) or less, optionally about 1000 psig (6.9 MPag) or less, optionally about 500 psig (3.4 MPag) or less;
- exposing at least a portion of the bottoms product to the catalyst under second effective slurry hydroconversion conditions to form at least a second plurality of liquid products and a second bottoms product;
- and
- recycling at least a portion of the second bottoms product, the recycled portion of the second bottoms product being combined with the heavy oil feedstock prior to exposing the heavy oil feedstock under the first slurry hydroconversion conditions.
A method for processing a heavy oil feedstock, comprising:
- providing a heavy oil feedstock having a 10% distillation point of at least about 650° F. (343° C.);
- exposing the heavy oil feedstock to a catalyst under first effective slurry hydroconversion conditions to form an effluent comprising at least a plurality of liquid products and a bottoms product, the first effective slurry hydroconversion conditions comprising a hydrogen partial pressure of about 1500 psig (10.3 MPag) or less;
- exposing at least a portion of the bottoms product to a second catalyst under second effective slurry hydroconversion conditions to form at least a second plurality of liquid products and a second bottoms product;
- and
- recycling at least a portion of the second bottoms product, the recycled portion of the second bottoms product being combined with the heavy oil feedstock prior to exposing the heavy oil feedstock under the first slurry hydroconversion conditions.
The method of any of the above claims, wherein the 10% distillation point of the heavy oil feedstock is at least about 900° F.
The method of any of the above claims, wherein the heavy oil feedstock has a Conradson carbon residue of greater than about 5 wt %.
The method of any of the above claims, wherein the heavy oil feedstock has a Conradson carbon residue of less than about 30 wt %.
The method of any of the above claims, further comprising:
- combining at least a portion of one or more of the first plurality of liquid products with at least a portion of one or more of the plurality of second liquid products;
- hydroprocessing the combined liquid products;
- and
- fractionating the combined liquid products.
The method of any of the above claims, wherein the first effective slurry hydroconversion conditions are effective for conversion of about 25 wt % to about 60 wt % of the heavy oil feedstock relative to a conversion temperature of at least about 975° F. (524° C.).
The method of any of the above claims, wherein the first effective slurry hydroconversion conditions and the second slurry hydroconversion conditions are effective for a combined conversion of at least about 90 wt % of the heavy oil feedstock relative to a conversion temperature of at least about 975° F. (524° C.).
The method of any of the above claims, wherein the second effective slurry hydroconversion conditions comprise a catalyst concentration that is at least twice a catalyst concentration of the first effective slurry hydroconversion conditions.
The method of any of the above claims, wherein the hydrogen partial pressure of the first effective slurry hydroconversion conditions is about 1000 psig (6.9 MPag) or less, optionally about 500 psig 3.4 MPag) or less.
The method of any of the above claims, wherein the hydrogen partial pressure of the second effective slurry hydroconversion conditions is at least about 2000 psig (13.8 MPag).
The method of any of the above claims, wherein a temperature of the second effective slurry hydroconversion conditions is greater than a temperature of the first effective slurry hydroconversion conditions by about 10° C. to about 80° C.
The method of any of the above claims, further comprising fractionating the first slurry hydroconversion effluent to form at least one of a naphtha fraction or a distillate fuel fraction, and the bottoms fraction.
Dependencies are inferred from the claim text.