US3870623A

US3870623A - Hydroconversion process of residuum oils

Info

Publication number: US3870623A
Application number: US397071A
Authority: US
Inventors: Axel R Johnson; Ronald H Wolk; Seymour B Alpert
Original assignee: Hydrocarbon Research Inc
Current assignee: HRI Inc
Priority date: 1971-12-21
Filing date: 1973-09-13
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

Abstract

In processing high metals Venezuelan residuum, higher conversion of the 975*F plus fraction and improved operability can be obtained by maintaining a high catalyst addition rate to obtain reduced metals loading on the catalyst; it being determined that for a macroporous catalyst there is a limiting factor of metals deposition.

Description

United States Patent Johnson et al.

HYDROCONVERSION PROCESS OF RESIDUUM OILS Assignee:

Filed:

Inventors: Axel R. Johnson, North Babylon;

Ronald H. Wolk, Trenton, both of N.J.; Seymour B. Alpert, Calif.

York, NY.

Sept. 13, 1973 Appl. No.: 397,071

abandoned.

U.S. Cl 208/108, 208/48 R, 208/112,

Int. Cl Cl0g 13/02, ClOg 9/16, BOlj 11/74 Los Altos,

Hydrocarbon Research, Inc., New

Field of Search 208/108, 112, 164, 251 H Cotolyst in 54 22 i, Solids Level 3 Reactor IBJIQF 1 Distributor? Plate 2o 1. 56

Cotolyst Feed gogolyst no -16 Hydrogen Mar. 11, 1975 [56] References Cited UNITED STATES PATENTS 3,183,179 5/1965 Schuman l208/97 3,321,393 5/1967 Schuman et a1. 208/10 3,547,809 12/1970 Ehrlich et al. 208/143 3,553,106 l/197l Hamilton et a1. 208/251 H 3,622,500 1l/1971 Alpert et a1 208/111 3,819,509 6/1974 Wolk et a1. 208/216 Primary E.mminerDelbert E. Gantz Assistant Examiner-G. E. Schmitkons 2 Claims, 1 Drawing Figure Vopor Catalyst in Liquid Level46 K/Trop Troy40 LlqUld Product (To Fractionation) Solids Level 1.

Distributor Plate 20 Cotoiyst Out Hydrogen PiiTENTED l l 75 Catalyst in FIG.

Vapor Catalyst in Liquid Level46 Trap Troy40 (To Fractionation) 42 r- Reactor 34 Distributor Plate 20 Catalyst Out Hydrogen 1 HYDROCONVERSION PROCESS OF RESIDUUM OILS RELATED APPLICATION This is a continuation of application Ser. No. 210,436, filed Dec. 21, 1971, and now abandoned.

BACKGROUND OF THE INVENTION The ebullated bed system described by Johanson in US. Reissue Pat. No. 25,770 has proved successful in hydrogenation, including hydrocracking and hydrodesulfurization, of a wide variety of petroleum stocks. The advantages of high throughput, uniform temperature, low pressure drop and non-plugging characteristics have been of great benefit to residuum processors. Liquid phase conditions assure good catalyst contact with no substantial attrition.

ln processing vacuum residuum, such as Lagunillas, which contain in excess of 500 ppm of vanadium, conversion was limited to about 50 percent of the feed boiling above 975 F to lower boiling products in a nonreplacement catalyst system. The high metals levels and high asphaltene content of Venezuelan residuum makes them difficult to convert due to the rapid poisoning of catalyst. This results in a short onstream time and, therefore, low conversion rates are obtained. As the amount of metals deposition on the catalyst increases the residuum begins to coke in the reactor. The coking then causes the rapid defluidization of the catalyst bed and this requires that the reactor be then shut down. However, a catalyst replacement reactor system utilizing a catalyst replacement rate such that not more than about 23 percent of vanadium was deposited on the catalyst showed long term successful operations even in the 70-80 percent conversion range.

SUMMARY OF THE INVENTION A system for obtaining in excess of a 70 percent conversion of the 975 F plus fraction in high metals residuums is disclosed using an ebullated bed reactor system. This system operates by replacing the demetalization catalyst at a rate sufficient to limit vanadium deposition, thereby assuring continuous operability. The pro-- cess for this invention is carried out at temperatures from 750 to 850 F, pressures of 1,000 to 3,000 psig, space velocity of 0.2 to 2.0 V /hr/V (volume of feed per hour per volume of reactor) and a hydrogen circulation of 4,000 to l0,000 SCF of hydrogen per barrel of liquid product.

DESCRIPTION OF THE DRAWING The drawing is a schematic drawing of the preferred embodiment of the process for the hydroconversion of high metals content residua using a continuous demetalization catalyst replacement.

PREFERRED FORM OF EMBODIMENT may have a liquid distributor and catalystsupport 20 so that the liquid and gas passing upwardly through the reactor 18 will tend to place the catalyst in random motion in the liquid.

The catalyst particle size range isusually ofa narrow size range for uniform expansion and random motion of the catalyst bed under controlled liquid and gas flow conditions. While the overall range of sizes that can be used is usually between 3 and 325 mesh (USS), a once through operation uses catalyst in the 60 to 325 mesh range with a liquid velocity in the order of l to l0 gallons per minute per square foot of horizontal reaction space. Alternatively. larger catalyst, usually in the 3 to 60 mesh size, can be used by adequate recycle of oil to provide from about 10 to 60 gallons total liquid velocity per minutes per square foot of horizontal reactor space. The lifting effect of the hydrogen and oil are factors in the buoyancy of the catalyst.

High metals containing residua are considered heavy hydrocarbon oils. Such oils are most preferably hydrogenated with the use of catalytic macroporous microspheres. These macroporous microspheres are composed of platinum, palladium, molybdenum, nickel or cobalt and the oxides or sulfides thereof or mixtures thereof supported on an alumina or silica carrier or mixtures thereof as a carrier.

A macroporous microsphere catalyst according to this invention should be ofa type and fall within a given size range as hereinbefore described. At the same time the macroporous microspheres have a pore volume of from about 0.10 cc/g to 0.60 cc/g comprising pores larger than 250A and a pore volume of from about 0.30 cc/g to 0.50 cc/g comprising pores with a diameter of less than 250A. The total pore volume of the macroporous microspheres is between about 0.40 cc/g and about 1.10 cc/g. A preferred macroporous microsphere catalyst would have a pore volume of from about 0.2 to about 0.4 cc/g in pores with a diameter larger than 250A and a pore volume from about 0.35 to about 0.45 cc/g in pores with a diameter ofless than 250A and the total pore volume is between about 0.55 and about 0.85 cc/g.

The macroporous microspheres have an average size such that weight percent fall within a narrow size range and are ebullated by the upward flow of oil and hydrogen through the reactor during hydroconversion. The pore volume of the microspheres is critical as there must be a penetration of the hydrocarbon oil into the catalyst for at least a 3 percent gain in weight. These microspheres are more specifically disclosed in US. Pat. No. 3,622,500.

By the control of the microspherical catalyst particle size and density and the liquid and gas velocities and taking into account the viscosity of the liquid under the operating conditions, the catalyst bed may be expanded to have a definite solids level or interface indicated at 22 in the liquid. The settled or static level of the catalyst is considerably lower than level 22. Normally, bed expansion should be at least 10 percent and seldom over 300 percent of the static level.

The entire effluent is removed overhead at 24 and passed with such hydrogen as may be required from line 32 into the second stage reactor 34. This reactor is similar to the first stage reactor except that a vapor separating space 36 is provided at the top. The vapors. substantially solids-free and liquid-free are removed at 38 and a liquid is removed over trap tray 40 through line 42. The upper solids level is indicated at 44 and the upper liquid level is indicated at 46.

While we have shown microspherical catalyst addi-:

up on catalyst. Therefore, 80 percent of vanadium ends up on catalyst. 4

1 While we have shown and described the preferred form of embodiment of our invention, it will be appar-- 'ent that modifications may be made thereto without departing from the scope and spirit of the description herein and of the claims appended hereinafter.

TABLE I I ll III IV FEED A* A A B* 0* API 4.0 4.0 v 4.0 l8 8 71 S 2.75 2.75 2.75 2.2 2.7 ppm V 535 535 535 200 570 Vol. 71 975F+ 75 75 75 50 89 OPERATING CONDITIONS Temperature "F 830 840 830 825 820 Pressure psig Circulation 2250 2250 2250 2000 2000 H SCF/Bbl 5000 9000 5000 6000 6000 Space Velocity V,/hr/V 0.6 0.5 0.6 0.5 0.4 CONVERSION** 72% 81% 7371 75% 707:

Cat. Rate No./bbl. 0.36 0.36 0.l8 0.18 0.18 Vanadium on Spent Catalyst 2O 21 8 23 Reactor Operability Satisfac- Satisfac- Coked Satisfac- Coked tory tory tory C is Tia Juana V uum Bottoms.

"Conversion is dlsappearance of 975F plus material.

al., U.S. Pat. No. 3,547,809. The catalyst is added and removed at a high rate in the range of 0.2 to 0.5 lbs. of catalyst per barrel of feed oil so as to maintain the percent vanadium on the spent microspherical catalyst at less than 23 percent. Under these conditions the reactor operates without defluidization or coking.

In a reactor system of this type, the vapor overhead 38 is largerly hydrogen which may be purified by conventional means and after being appropriately reheated and recompressed, can be recyled to the hydrogen feed l n @2219 .32 .t21 2s1sa9 9r Although it is preferable to hydrogenate the feeds in a two stage system, a single stage is also suitable.

Table I shows the results of five operations for the hydrogenation of heavy metals containing residuum using macroporous microspheres as the catalyst. From the results it can be seen that the microspherical catalyst must be added and removed at a rate such that the spent catalyst has less than 23 percent vanadium deposited on it. In this manner at least 70 percent conversion of the feed is maintained without the defluidization and coking of the microspherical catalyst bed taking place.

Above 70 percent conversion. 85 percent of vanadium in the feed is removed. 94 percent of which ends We claim:

1. In a process for the continuous hydrogenation of a Lagunillas vacuum bottoms having in excess of 500 ppm of metals from the group of vanadium and nickel wherein the residuum and hydrogen are passed upwardly through a reaction zone containing a macropt rous microspherical particulate catalyst being closely sized within the range of 60 to 325 U.S. Standard mesh at a rate to place the microspherical catalyst in random motion in the liquid without substantial carryover from I the reaction zone and wherein the operating conditions are within a pressure range of 1,000 to 3,000 P316, and a temperature range of 750 to 850F and a liquid space velocity of 0.2 to 2.0 V,/hr/V, such as to maintain conversion of at least 80 percent of the portion of the residuum boiling above 975F to material boiling below 975F wherein the improvement comprises:

adding said catalyst to and removing said catalyst from the reaction zone at a rate between 0.2 and 0.5 pounds of catalyst per barrel of feed oil such that the percent of vanadium on the spent catalyst is less than 23 percent. 2. The process of claim 1 wherein the catalyst addition and withdrawal rate is between 0.4 and 0.5 pounds of catalyst per barrel of feed oil.

Claims

1. IN A PROCESS FOR THE CONTINUOUS HYDROGENATION OF A LAGUNILLAS VACUUM BOTTOMS HAVING IN EXCESS OF 500 PPM OF METALS FROM THE GROUP OF VANADIUM AND NICKEL WHEREIN THE RESIDUUM AND HYDROGEN ARE PASSED WARDLY THROUGH A REACTION ZONE CONTAINING A MACROPOROUS MICROSPHERICAL PARTICULATE CATALYST BEING CLOSELY SIZED WITHIN THE RANGE OF 60 TO 325 U.S. STANDARD MESH AT A RATE TO PLACE THE MICROSPHERICAL CATALYST IN RANDOM MOTION IN THE LIQUID WITHOUT SUBSTANTIAL CARRYOVER FROM THE REACTION ZONE AND WHEREIN THE OPERATING CONDITIONS ARE WITHIN A PRESSURE RANGE OF 1,000 TO 3,000 PSIG, AND TEMPERATURE RANGE OF 750* TO 850*F AND A LIQUID SPACE VELOCITY OF OF 0.2 TO 2.0 VF/HR/VR SUCH AS A TO MAINTAIN CONVERSION OF AT LEAST 80 PERCENT OF THE PORTION OF THE RESIDUUM BOILING ABOVE 975*F TO MATERIAL BOILING BELOW 975*F WHEREIN THE IMPROVEMENT COMPRISES: ADDING SAID CATALYST TO AND REMOVING SAID CATALYST FROM THE REACTION ZONE AT A RATE WHEREIN 0.2 AND 0.5 POUNDS OF CATALYST PER BARREL OF FEED OIL SUCH THAT THE PRECENT OF VANADIUM ON THE SPENT CATALYST IS LESS THAN 23 PERCENT.

1. In a process for the continuous hydrogenation of a Lagunillas vacuum bottoms having in excess of 500 ppm of metals from the group of vanadium and nickel wherein the residuum and hydrogen are passed upwardly through a reaction zone containing a macroporous microspherical particulate catalyst being closely sized within the range of 60 to 325 U.S. Standard mesh at a rate to place the microspherical catalyst in random motion in the liquid without substantial carryover from the reaction zone and wherein the operating conditions are within a pressure range of 1,000 to 3,000 PSIG, and a temperature range of 750* to 850*F and a liquid space velocity of 0.2 to 2.0 Vf/hr/Vr such as to maintain conversion of at least 80 percent of the portion of the resIduum boiling above 975*F to material boiling below 975*F wherein the improvement comprises: adding said catalyst to and removing said catalyst from the reaction zone at a rate between 0.2 and 0.5 pounds of catalyst per barrel of feed oil such that the percent of vanadium on the spent catalyst is less than 23 percent.