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US 12,351,762 B2Granted
Hydrocarbon pyrolysis of feeds containing mercury
AssigneeExxonMobil Engineering & Technology Company
InventorsKeng-Fai Kuan, Boon Hwa Sow, Rodney S. Smith
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Abstract
The invention generally relate to processes, systems, and methods for the pyrolysis of hydrocarbon feeds containing one or more forms of mercury, e.g., the steam cracking of heavy oil, such as crude oil. Effluent from the pyrolysis is processed to remove various forms of mercury produced during the pyrolysis and/or carried over from the hydrocarbon feed.
Claims30
A method for performing steam cracking, comprising:
- desalting a hydrocarbon feed comprising hydrocarbon and 25 wppb or more of a first mercury material to form a desalted feed, wherein the feed comprises one or more crude oils, crude fractions, or a combination thereof;
- heating at least a portion of the desalted feed to form a preheated feed;
- separating a pyrolysis feed and a higher boiling stream from at least a portion of the preheated feed, the pyrolysis feed having a final boiling point of 760° C. or less;
- exposing at least a portion of the pyrolysis feed to steam cracking conditions to form a steam cracker effluent;
- separating at least a naphtha and a process fluid comprising C2-C6 olefins from the steam cracker effluent, wherein (i) the process fluid comprises a second mercury material, (ii) the naphtha comprises a third mercury material, and (iii) the second and third materials include forms of mercury produced from the first mercury material during the steam cracking;
- separating from the process fluid (i) a process gas comprising C2-C3 olefin and a process liquid comprising C4-C6 olefin-;
- and
- removing at least a portion of the second mercury material from at least a portion of one or more of (i) the process fluid, (ii) the process gas, and (iii) the process liquid,
- wherein at least a portion of the second mercury material is removed in at least one regenerable mercury removal stage, the method further comprising:
- conducting at least a portion of the process fluid, at least a portion of the process gas, or at least a portion of the process liquid as abed feed flow to the regenerable mercury removal stage;
- stopping the bed feed flow to the mercury removal stage;
- passing a regeneration gas through the mercury removal stage to form a flue gas having a mercury content of 0.1 wppm or more;
- passing the flue gas through a fixed bed mercury trap to form a reduced-mercury flue gas having a mercury content of 100 wppb or less;
- and
- restoring the bed feed flow to the mercury removal stage and continuing passing of at least a portion of the flue gas through the mercury trap.
12 more elements
A steam cracking reaction system, comprising:
- a desalter;
- a steam cracking furnace comprising a convection zone inlet, a convection zone outlet, a radiant zone inlet, and a radiant zone outlet, the desalter being in fluid communication with the convection zone inlet;
- a vapor-liquid separator in fluid communication with the convection zone outlet and the radiant zone inlet;
- a cooling and fractionation stage in fluid communication with the radiant zone outlet, the cooling and fractionation stage comprising a naphtha outlet and a process fluid outlet;
- a compressor and acid gas removal stage in fluid communication with the process fluid outlet;
- one or more drying stages in fluid communication with the compressor and acid gas removal stage;
- and
- at least one fixed bed mercury trap in fluid communication with the one or more drying stages.
5 more elements
A steam cracking process, comprising:
- providing a hydrocarbon feed comprising hydrocarbon and mercury material, wherein the mercury is present in an amount A1 based on the weight of the hydrocarbon feed;
- determining A1;
- establishing a flow of the hydrocarbon feed into a steam cracking furnace facility to produce a steam cracker effluent;
- separating from the steam cracker effluent a naphtha comprising C5+ hydrocarbon and mercury;
- upgrading the naphtha, wherein
- (i) the upgrading includes both mercury removal and hydroprocessing of the naphtha,
- (ii) the mercury removal and hydroprocessing are carried out in at least one hydroprocessing reactor containing a predetermined first amount (A2) of a first active material and a predetermined amount (A3) of a second active material,
- (iii) A2 is effective for the mercury removal,
- (iv) A3 is effective for the hydroprocessing, and
- (v) A2 and A3 are determined from A1.
7 more elements
A method for performing steam cracking, comprising:
- desalting a hydrocarbon feed comprising hydrocarbon and 25 wppb or more of a first mercury material to form a desalted feed, wherein the feed comprises one or more crude oils, crude fractions, or a combination thereof;
- heating at least a portion of the desalted feed to form a preheated feed;
- separating a pyrolysis feed and a higher boiling stream from at least a portion of the preheated feed, the pyrolysis feed having a final boiling point of 760° C. or less;
- exposing at least a portion of the pyrolysis feed to steam cracking conditions to form a steam cracker effluent;
- separating at least a naphtha and a process fluid comprising C2-C6 olefins from the steam cracker effluent, wherein (i) the process fluid comprises a second mercury material, (ii) the naphtha comprises a third mercury material, and (iii) the second and third materials include forms of mercury produced from the first mercury material during the steam cracking;
- separating from the process fluid (i) a process gas comprising C2-C3 olefin and a process liquid comprising C4-C6 olefin;
- and
- removing at least a portion of the second mercury material from at least a portion of one or more of (i) the process fluid, (ii) the process gas, and (iii) the process liquid,
- wherein
- a) the method further comprises passing the at least a portion of the process fluid into an acid gas removal stage before the removal of at least a portion of the second mercury material from the process fluid,
- b) the removing at least a portion of the second mercury material includes exposing the process gas to a mercury removal stage that includes at least one process gas drier,
- c) the removing at least a portion of the second mercury material includes exposing the process liquid to a mercury removal stage comprising a process liquid drier, or
- d) a combination of two or more of a), b), and c).
10 more elements
Dependencies are inferred from the claim text.