Combination process for upgrading residual oils

• US 4,894,141 A
• Filed: 01/03/1984
• Issued: 01/16/1990
• Est. Priority Date: 09/01/1981
• Status: Expired due to Fees

• Current Assignee: Ashland Oil, Inc. (Ashland Global Holdings, Inc.)
• Original Assignee: Ashland Oil, Inc. (Ashland Global Holdings, Inc.)
• Inventors: Busch, Lloyd E., Zandona, Oliver, Walters, Paul W.
• Primary Examiner(s): Myers, Helane
• Application Number:
  US06/567,487
• Time in Patent Office: 2,205 Days
• Field of Search: 208/73, 208/88, 208/251 R, 208/91, 208/251 H
• US Class Current: 208/73
• CPC Class Codes: B01D 53/508 by treating the gases with solids
• CPC Class Codes: C10G 11/18 according to the "fluidised-bed" technique

Abstract

A process for upgrading topped crude oils and residual portions comprising material boiling above 552° C. (1025° F.) by the combination of partial demetallizing and decarbonizing of the residual oil before effecting zeolite catalytic cracking thereof is described in conjunction with a product separation process, a combined hydrocarbon gas product concentration section and the use of parallel arranged CO boilers to produce sulfur free flue gas and steam. Steam generated by the combination operation effectively reduces the energy requirement of the combustion process.

Claims

1. A method for upgrading high boiling residual portions of crude oils comprising metal contaminants, porphyrins, asphaltenes and high molecular weight multi-ring hydrocarbon material, which method comprises:

A. charging a high boiling residual portion of crude oil admixed with diluent in contact with suspended upflowing substantially inert fluidizable solids particulate material at an elevated thermal visbreaking temperature in a riser contact zone for a time sufficient to recover therefrom a vaporous hydrocarbon product higher boiling than gasoline partially decarbonized and demetallized to a lower contaminating metals level,

B. quenching said vaporous product of thermal visbreaking below its dew point after separation from solids,

C. charging quenched thermally modified high boiling hydrocarbon product comprising metal contaminants in admixture with thermally produced naphtha in contact with a crystalline zeolite cracking catalyst maintained under cracking conditions for a hydrocarbon residence time in a riser cracking zone in the range of 0.5 to 3 second providing a riser outlet product temperature within the range of 510°

C. (950°

F.) to 593°

C. (1100°

F.),

D. recovering a hydrocarbon conversion product of said zeolite cracking operation comprising gasoline, lower and higher boiling product components separated from catalyst particles,

E. separating a combined C₄ minus wet gas product stream of said visbreaking and zeolite catalyst cracking operating to recover a C₃ -C₄ rich fraction separately from a C₂ minus dry gas product fraction, and

F. regenerating said crystalline zeolite containing catalyst comprising carbonaceous deposits of said cracking operating in a sequence of separate regeneration zones provided with catalyst cooling transferred between zones under conditions to produce a CO rich flue as and high temperature catalyst particles suitable for recycle to said zeolite cracking operation;

wherein vaporous hydrocarbon products of each said inert solids and catalyst contacting steps comprise naphtha and lower boiling materials which are processed together under conditions to effect the recovery of a C₃ minus dry gas stream from a C₃ -C₄ rich gaseous product stream and a naphtha boiling range product separated from a light cycle oil product is used to effect separation of C₂ minus products from a C₂ -C₄ rich product stream.

2. The method of claim 1 wherein zeolite catalytic cracking of the thermally modified hydrocarbon product of visbreaking in the presence of diluent gaseous materials is accomplished in a riser contact zone at a velocity providing a hydrocarbon residence time in the riser reactor less than 2 seconds.

4. The method of claim 1 wherein regeneration of inert solid particulates is initially accomplished in an upflowing fluid mass of solid particulate superimposed by an upflowing confined more dilute suspension of regenerated solid particles in flue gas products of combustion, the upwardly flowing confined suspension is separated by momentum differential upon discharge therefrom to recover flue gas from regenerated solid particles, a portion of the regenerated solid particles separated from the flue gas is passed to a lower portion of said upflowing fluid mass of particles by a standpipe provided with an indirect heat exchange zone therein for generating steam and effect partial cooling of the regenerated solid particles, and another portion of said collected regenerated solid particles collected at an elevated temperature is passed directly to said thermal visbreaking zone.

5. The method of claim 1 wherein the thermal visbreaking zone is a riser contacting zone provided with a plurality of vertically spaced apart oil feed inlets arranged to contact an upflowing suspension for a hydrocarbon residence contact time in the riser for one of about 0.5 seconds, about 1.2 seconds or about 1.5 seconds, depending upon the oil feed inlet is utilized.

6. The method of claim 1 wherein a vaporous product of thermal visbreaking separated from inert solids in a separation zone is quenched substantially immediately following withdrawal from said separation zone to restrict further thermal conversion thereof and before introduction thereof to a downstream main column fractionation zone of the product recovery section of the thermal visbreaking operation.

7. The method of claim 1 wherein regeneration of the zeolite cracking catalyst is accomplished in a two stage regeneration operation comprising dense fluid catalyst bed containing with oxygen containing regeneration gas in each stage thereof wherein hot product flue gas of the second stage catalyst regeneration operation pass upwardly into and through an upper dense fluid catalyst bed of a first stage of catalyst regeneration, said second stage of catalyst regeneration being accomplished at a temperature equal to, below, or higher than, said first stage of catalyst regeneration, retaining some residual coke on the catalyst recovered from the second stage of regeneration and recovering a CO rich flue gas from the first stage of catalyst regeneration.

8. The method of claim 4 wherein the standpipe with a heat exchange zone provides for the major flow of catalyst from the first regeneration zone to the bed of catalyst in the second regeneration zone and a second stream of hot catalyst from the first regeneration zone to the second regeneration zone when needed for temperature adjustment of the catalyst bed in the second regeneration zone.

9. The method of claim 4 wherein about 75 percent of the combustion air required to regenerate the catalyst is charged to a lower portion of the catalyst bed in the first regeneration zone and the remaining 25 percent of that required to satisfactory regenerate the catalyst is charged to the lower portion of the bed of catalyst in the second lower regeneration zone.

10. The method of claim 1 wherein catalytic cracking of the hydrocarbon product of thermal visbreaking is accomplished with a zeolite catalyst in a riser contact zone by introducing the hydrocarbon product of thermal visbreaking into an upflowing high velocity suspension of zeolite catalyst suspended in a diluent material and the suspension thus formed is velocity reduced by increasing the diameter of the riser contact zone in a downstream portion thereof.

3. A method for upgrading high boiling residual portions of crude oils comprising metal contaminants, porphyrins, asphaltenes and high molecular weight multi-ring hydrocarbon material, which method comprises:

A. charging a high boiling residual portion of crude oil admixed with diluent in contact with suspended upflowing substantially inert fluidizable solids particulate material at an elevated thermal visbreaking temperature in a riser contact zone for a time sufficient to recover therefrom a vaporous hydrocarbon product higher boiling than gasoline partially decarbonized and demetallized to a lower contaminating metals level,

B. quenching said vaporous product of thermal visbreaking below its dew point after separation from solids,

C. charging quenched thermally modified high boiling hydrocarbon product comprising metal contaminants in admixture with thermally produced naphtha in contact with a crystalline zeolite cracking catalyst maintained under cracking conditions for a hydrocarbon residence time in a riser cracking zone in the range of 0.5 to 3 second providing a riser outlet product temperature within the range of 510°

C. (950°

F.) to 593°

C. (1100°

F.),

D. recovering a hydrocarbon conversion product of said zeolite cracking operation comprising gasoline, lower and higher boiling product components separated from catalyst particles,

E. separating a combined C₄ minus wet gas product stream of said visbreaking and zeolite catalyst cracking operation to recover a C₃ -C₄ rich fraction separately from a C₂ minus dry gas product fraction, and

F. regenerating said crystalline zeolite containing catalyst comprising carbonaceous deposits of said cracking operating in a sequence of separate regeneration zones provided with catalyst cooling transferred between zones under conditions to produce a CO rich flue gas and high temperature catalyst particles suitable for recycle to said zeolite cracking operation;

wherein a CO combustion zone is provided for indirectly generating high pressure steam from regeneration flue gases in the presence of a fluid bed of limestone particles about steam generating indirect heat exchange zone for removing sulfur from the CO combustion product gases before venting to the atmosphere.

11. The method of claim 3 wherein vaporous products of said thermal visbreaking are quenched below the product dew point immediately upon recovering from the visbreaking zone to restrict further thermal conversion thereof.

12. The method of claim 3 wherein a naphtha product of said thermal visbreaking is upgraded with said zeolite catalyst in a suspension prior to contact with said partially decarbonized and demetallized oil feed.

13. A method for upgrading a distress hydrocarbon stock selected from the group consisting of topped crudes, residual oils, resids, reduced crudes, other heavy hydrocarbon materials obtained from coal, oil, shale, tar sands, and combinations thereof, which method comprises:

A. forming a confined first upflowing suspension of relatively inert particular solids in a lift gas comprising a gaseous product of said method in a first riser contact zone at an elevated temperature,

B. charging said distress hydrocarbon stock initially admixed with a water product obtained from said method into said first upflowing suspension under conditions providing a thermal visbreaking temperature and residence time sufficient to effect partial demetallizing and decarbonizing of said distress hydrocarbon stock and to produce a thermally-cracked hydrocarbon product stream comprising a first vaporous hydrocarbon product and coked particulate solids, said first riser contact zone being provided with a plurality of vertically spaced apart hydrocarbon feed inlet means to furnish the capability of varying said residence time of said distress hydrocarbon stock in said first riser contact zone,

C. discharging said thermally-cracked hydrocarbon product from said first riser contact zone under ballistic momentum separation conditions to separate said first vaporous hydrocarbon product comprising partially demetallized and decarbonized hydrocarbon components from said coked particulate solids and to recover said first vaporous hydrocarbon product in an annular zone in open communication with a plurality of downstream cyclone separation zones for recovery of hydrocarbon vapors from entrained solid particulate fines,

D. quenching said first vaporous hydrocarbon product to a temperature below its dew point immediately upon being separated from said coked particulate solids to restrict further thermal conversion thereof and to provide a quenched hydrocarbon product,

E. recovering from said quenched hydrocarbon product separately a 221°

C.-plus product, a first C₄ -minus wet gas product, and any naphtha product of thermal visbreaking,

F. forming in a second riser contact zone a second upflowing suspension of a zeolite cracking catalyst in a lift gas comprising a gas product of thermal cracking, a gas product of catalytic cracking, or a gas product of thermal and catalytic cracking,

G. charging said 221°

C.-plug product admixed with water and thermal naphtha obtained from said first riser contact zone into a downstream portion of said second upflowing suspension at a point restricting the hydrocarbon feed riser residence time to within the range of about 0.5 to about 2 seconds to obtain a catalytically-cracked hydrocarbon product stream comprising a second vaporous hydrocarbon product and spent catalyst particles containing carbonaceous deposits, said second riser contact zone being provided with a plurality of vertically spaced apart hydrocarbon feed inlet means to furnish the capability of varying the residence time of said 221°

C.-plus product in said second riser contact zone,

H. discharging said catalytically-cracked hydrocarbon product stream from said second riser contact zone under ballistic momentum separation conditions to separate said second vaporous hydrocarbon product comprising gasoline and light cycle oils from said spent catalyst particles and to recover said second vaporous hydrocarbon product in an annular zone in open communication with plurality of downstream cyclone separation zones for recovery of hydrocarbon vapors from entrained catalyst particulate fines, and recovering from said second vaporous hydrocarbon product separately a second C₄ -minus wet gas product, said gasoline, and said light cycle oils,

I. regenerating said coked particulate solids from said first riser contact zone in an upflowing fluid mass of particulate solids superimposed by an upflowing confined more dilute suspension of regenerated solid particles in a flue gas products of combustion, separating the upflowing confined more dilute suspension by ballistic momentum separation conditions into regenerated solid particles and flue gas products of combustion, passing a portion of said regenerated solid particles to a lower portion of said upflowing fluid mass of particulate solids via a standpipe provides with an indirect heat exchange zone therein for generating steam and effecting partial cooling of the regenerated solid particles passing therethrough and passing a second portion of regenerated solid particles directly to said first upflowing suspension,

J. regenerating said spent catalyst particles from said second riser contact zone in a two-stage regeneration operation comprising a first stage located above a second stage, a dense fluid catalyst bed with oxygen-containing regeneration gas being present in each stage, passing hot product flue gas produced in said second stage upwardly into and through a dense fluid catalyst bed in said first stage, passing said spent catalyst particles into said first stage to contact said hot product flue gas produced in said second stage to provide partially regenerated catalyst particles and a CO-rich flue gas, passing said partially regenerated catalyst particles into said second stage where additional removal of carbonaceous deposits occurs to provide said hot product flue gas and catalyst particles retaining some residual coke, recovering said CO-rich flue gas from said first stage and said catalyst particles retaining some residual coke from said second stage,

K. passing said catalyst particles retaining some residual coke to said second riser contact zone to form said upflowing suspension of a zeolite cracking catalyst in a lift gas, the temperature of said catalyst particles retaining some residual coke being sufficiently elevated to convert said 221°

C.-plus product being passed to said second riser contact zone into said catalytically-cracked hydrocarbon product stream comprising gasoline and light cycle oils,

L. generating indirectly steam from regeneration flue gases by passing said regeneration flue gases into a CO-combustion zone in the presence of one or more fluid beds of limestone particles about a steam generating indirect heat exchange zone, sulfur being removed from CO-combustion product gases prior to said CO-combustion product gases being vented to the atmosphere,

M. combining said first C₄ -minus wet gas product obtained from said first riser contact zone with second second C₄ -minus wet gas product obtained from said second riser contact zone to form a combined C₄ -minus wet gas product, and

N. processing said combined C₄ -minus wet gas product under conditions to effect the recovery of a C₂ -minus dry gas stream from a C₃ -C₄ -rich gaseous product stream, a naphtha-boiling range product separated from said light cycle oil product being used to effect separation said C₂ -minus dry gas stream from said C₃ -C₄ -rich gaseous product stream.

14. The method of claim 13 wherein inert solid particulate material separated from vaporous product of thermal visbreaking is regenerated as an upflowing suspension of higher particle concentration in a lower portion than an upper portion of a regeneration zone, the upflowing suspension is discharged from the upper end of the regeneration zone under ballistic momentum separation conditions whereby separated product flue gases are recovered in an annular zone in open communication with a plurality of downstream parallel arranged flow through cyclone separation zones for recovery of flue gases separated from entrained solid particulate fines, passing solid particle material thus separated and recovered to said visbreaking zone at an elevated temperature sufficient to effect thermal visbreaking of said residual portion of crude oil, and passing a portion of the regenerated solid particulate material thus recovered through a cooling zone and then to a bottom portion of the upflowing suspension in said regeneration zone.

15. The method of claim 13 wherein the zeolite cracking catalyst separated from vaporous product is stripped and then passed sequentially through two stages of dense fluid catalyst bed regeneration flowing generally countercurrent to combustion supporting oxygen containing regeneration gas, a portion of the catalyst partially regenerated in the first regeneration zone is partially cooled before passage to said dense fluid catalyst bed second regeneration zone for contact with combustion supporting oxygen containing gas, combustion product gases of said second regeneration zone are passed into the lower portion of the dense fluid bed of catalyst in said first regeneration zone, and regenerated catalyst particles are passed from said second regeneration zone to said catalytic cracking zone at a temperature sufficiently elevated to convert quenched hydrocarbon vapors passed thereto to form a vaporous product boiling above 482°

C. (900°

F.) and comprising gasoline and light cycle oil product.