JPH04239094A - Method for desulfurizing and demetallizing residual oil - Google Patents

Abstract

PURPOSE: To improve the effects of residual oil desulfurization and demetalation by blending the residual oil with a diluent of a low boiling point and hydrogenating the blend in specified conditions.

CONSTITUTION: A blend mainly containing residual oil is prepared by mixing residual oil with a diluent having a boiling point between 24°C and the boiling point of the residual oil. Next, the blend is brought into contact with a hydrogenation catalyst in conditions including temperature of 316-468°C, hydrogen pressure of 4,240-27,700 kPa, and space velocity (WHSV) of about 0.05-10. Cracked distillate such as gas oil, vacuum distillate, light and heavy cycle stock is used as the diluent.

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to an improved process for desulfurizing and demetallizing resid oils, such as vacuum resid oils. In the present invention, desulfurization and/or demetallization substantially removes or reduces impurities from the residual oil.

0002

BACKGROUND OF THE INVENTION Impurities affect catalysts, for example as catalyst poisons, in the subsequent contact treatment of residual oils, such as in the production of gasoline.

0003

SUMMARY OF THE INVENTION The present invention provides for preparing a blend in which residual oil is the main component by blending residual oil with a diluent having a boiling point in the range of 204° C. to the boiling point of the residual oil; 4240~27700kPa (600~40
00 psig) hydrogen pressure, 316-468°C (600-
875° F.) and a space velocity between 0.05 and 10, comprising contacting the blend with a hydroprocessing catalyst.

In one aspect of the invention, the residual oil is converted into gas oil, distillate oil or FC under the above conditions in the presence of a catalyst selected from the group consisting of silica, alumina or silica-alumina.
C. Contact with circulating raw material diluent. One result is that the metal impurity content of the treated resid is lower than that of a resid treated under the same conditions in the absence of gas oil, distillate or FCC recycle feedstock. Another result is that the low-boiling fraction (
The sulfur content of the residual oil treated under these conditions in the presence of gas oil, distillate oil or FCC recycled feedstock) is higher than that of the residual oil treated under the same conditions in the absence of gas oil, distillate oil or FCC recycled oil. It's a small thing.

The objectives of hydrotreating resid oils are removal of metals such as nickel and vanadium, reduction of sulfur products and reduction of CCR products. Kinetic limitations and catalyst contamination by carbonaceous and metal deposits are two common problems encountered in such processes. Atmospheric residues boil at 316-427°C (600-800°F) and vacuum residues boil at 482-593°C (900-1100°F).
F). Preferably, the resid to be demetalized and/or desulfurized according to the invention is a vacuum resid. Residual oil, by definition, is an unvaporized liquid or solid residual oil from a crude oil distillation or cracking process. Vacuum retentates are obtained from vacuum distillation in which the distillation temperature and the boiling temperature of the distillate material are lowered at reduced pressure in order to avoid decomposition and cracking of the material being distilled. Thus, in a preferred embodiment, the first step is to provide a vacuum resid, and the first step comprising the above purpose is the vacuum distillation of crude oil to provide the vacuum resid by standard methods.

Low-boiling diluents for residual oils are atmospheric and vacuum gas oils, or LCO (light circulating oil) and HCO (
including cracked distillate oils such as heavy circulating oils). Gas oil is a petroleum distillate oil that has a viscosity intermediate between that of kerosene and lubricating oil and boils at temperatures between about 400 and about 800 degrees Fahrenheit. Distillate oils include gasoline, kerosene and light lubricating oils. In a preferred embodiment, the diluent is an aromatic stream such as cracked FCC distillate. The cracked distillate as an aromatic stream contains LCO and HCO. Combining the aromatic stream provided by the cracked distillate with the resid in the process of the invention has a beneficial effect on catalyst deactivation.

[0007] The residual oil is blended with a low boiling diluent. The resulting blend may contain up to 50% by volume diluent. In particular, the blend contains about 10-30% diluent by volume. Preferred levels of diluent are determined for each combination of vacuum resid and diluent, including a diluent with a lower boiling point than the resid in an amount effective to promote demetalization and desulfurization under the hydroprocessing conditions described below. exists. According to the invention, the rate increase of demetalization and/or desulphurization is 1
It can be up to 00%. When the speed increase is 100% for a particular diluent, the speed increase tends to increase with the viscosity of the residual oil being treated. The viscosity of residual oil varies depending on where it is produced.

The blend of resid and diluent was subjected to the following hydroprocessing conditions in fixed bed, ebullated bed or moving bed reactors well known to those skilled in the art for demetallization and desulfurization of petroleum resid. can be attached. Hydrotreating conditions include a catalyst.

By definition, hydroprocessing requires a flow of hydrogen. The hydrogen pressure in the method of the present invention is 4240~2
7700 kPa (600 to about 4000 psig). The high temperature in the method of the present invention is about 316-468°C (6
00 to about 875°F). The space velocity (WHSV) is 0.05-10.

The catalyst for the demetalization and/or desulphurization of the residual oil may be conventional. These compositions useful as catalysts include silica, alumina or silica-alumina.

Under the conditions described above, the rate constant for demetalization and/or desulfurization of the hydrotreated resid in the presence of the low-boiling diluent described above increases. Because of this increase, certain proportions of diluent can be hydrotreated in the same reactor without undesirable consequences, even having a positive influence on the treatment of the vacuum resid fraction.

The product of this process can be fractionated and transferred to other conventional equipment, if desired, or used directly as the final product.

[0013]

EXAMPLES Example 1 Arablite (AL) vacuum resid was hydrotreated at various space velocities in the presence of 30% LCO. Figure 1 shows the effect of LCO on the rate constant of nickel removal,
Figure 2 shows the effect on vanadium removal. 30%LC
The presence of O promotes demetalization more than the ratio of the two expressed by the increase in rate constant. For example, 371°C (700°F
), a pressure of 13900 kPa (2000 psig) and a hydrogen circulation rate of 890 v/v (5000 SCF/BBL), the calculated apparent rate constant for nickel removal is 0.022 when treating only the resid. Co-treatment with 30% LCO increases the rate constant to 0.045. Similarly, co-treatment with 30% LCO increases the rate constant for vanadium removal from 0.021 to 0.05. This increased demetalization rate is indicative of a lower metal content in the product.

Example 2 AL vacuum resid was hydrotreated in the presence of 30% LCO. The sulfur content in the residue fraction was calculated by subtracting the residual sulfur in the LCO fraction after treatment. Figure 3 compares the observed desulfurization of the vacuum resid in the co-processing with the desulfurization expected in the treatment of the vacuum resid itself. Under the same operating conditions as in Example 1, the rate constant of desulfurization was again increased from 0.2 to 0.36 by co-treatment. This represents a very low sulfur content in the product stream.

Example 3 To independently demonstrate the influence of LCO on catalyst deactivation, the LCO itself was treated for 4 days with an equilibrated catalyst under the same conditions as in Example 1. Catalyst performance for resid hydrotreating was compared before and after the LCO run. As shown below, the metal removal rate from the AL residual oil increased from 43 to 46%, and the sulfur removal rate increased from 38 to 41%.

Comparison of residual oil hydrotreatment
Raw material before run
Post-run operating conditions Pressure, kPa
13400 13400
(psig)
(2000) (20
00) Temperature, °C
321
321 (°F)
(610)
(610) WHSV

0.8 0.8 Product characteristics Ni, ppm
9.0 6.9
6.5V, ppm
31.0 16.0
15.0 S, weight%
2.9 0
．． 9 0.75 Demetallization, %

43 46 Desulfurization, %

38 41

00
[17] The above results show that the presence of LCO actually restores the catalyst activity. That is, LCO co-treatment is expected to slow catalyst deactivation.

Example 4 AL vacuum residual oil was heated at 321°C and 399°C (610°C
°F and 750 °F), 13,900 kPa (2
000 psig) pressure and 890 v/v (5000 psig)
It was co-processed with 20% vacuum gas oil and 10% light distillate at a hydrogen circulation rate of SCF/BBL). To track sulfur removal from the vacuum resid, the product was separated to give an 850+ (°F) portion for determination of sulfur content. In Figure 4, the effect of diluent addition on nickel removal from vacuum retentate is compared at various reactor temperatures. Similar improvements with co-treatment in vanadium and sulfur removal from residual oil are shown in Figures 5 and 6, respectively. As shown therein, co-treatment substantially improves metal and sulfur removal capabilities.

[Brief explanation of the drawing]

FIG. 1 is a graph plotting the ratio of Ni in the product to Ni in the feed versus WHSV, showing the effect of light circulating oil (LCO) on nickel removal.

FIG. 2 is a graph plotting the ratio of V in the product to V in the feed versus WHSV, showing the effect of LCO on vanadium removal.

FIG. 3 is a graph plotting the change in sulfur content in residual oil against WHSV, showing the influence of LCO on residual oil desulfurization.

FIG. 4 is a graph plotting nickel content versus WHSV showing the effect of diluent on demetalization of 850+ (°F) residual oil.

FIG. 5 is a graph plotting vanadium content versus WHSV showing the effect of diluent on demetalization of 850+ (°F) residual oil.

FIG. 6 is a graph plotting sulfur content versus WHSV showing the effect of diluent on desulfurization of 850+ (°F) residual oil.

Claims (6)

[Claims] 1. A blend in which the residual oil is the main component is prepared by blending the residual oil with a diluent having a boiling point in the range of 204° C. to the boiling point of the residual oil;
Hydrogen pressure of 0kPa, high temperature of 316-468℃ and approx.
．． A process for desulfurizing and demetallizing resid oils comprising contacting a blend with a hydrotreating catalyst under conditions comprising a space velocity of 0.05 to 10. 2. The method of claim 1, wherein the diluent for the residual oil is selected from the group consisting of atmospheric gas oil, vacuum gas oil, and cracked distillate light and heavy circulating oils. 3. The method according to claim 1, wherein the residual oil is a vacuum residual oil. 4. A process according to claim 1, wherein the residual oil contains an effective amount of nickel or vanadium to act as a catalyst poison in downstream processing. 5. A process according to claim 1, wherein the amount of nickel or vanadium in the recovery blend is less than the amount effective to act as a catalyst poison. 6. A process according to claim 1, wherein the hydrotreating catalyst is selected from the group consisting of silica, alumina and silica-alumina.