SK140394A3 - Manufacturing process of crude material for high grade lubricating oils - Google Patents

Abstract

Lube oil feedstock is produced from atmospheric residue by: (1) vacuum distillation to give vacuum gas oil (VGO); (2) hydrotreating VGO to purify it; (3) hydrocracking purified VGO to produce light hydrocarbons; (4) fractionation to separate light hydrocarbons from unconverted oil (UCO); (5) vacuum distillation of UCO to produce feedstock; and (6) recycling UCO to hydrocracker. Also claimed is a related process in which only part of UCO is vacuum distilled and remainder is recycled to the hydrocracker.

Description

METHOD OF MANUFACTURE OF HIGH-QUALITY LUBRICATION OILS FROM UNCONVERTED OIL

Technical field

The invention relates to a process for producing a raw material for high-quality lubricating oils from unconverted oil and in particular to increase efficiency together with a method of continuously producing a raw material for high-quality lubricating oils from unconverted oil as a product of recycling in fuel hydrocracker.

BACKGROUND OF THE INVENTION

Fuel hydrocracking generally means a vacuum gas oil (VPO) conversion process. produced by a vacuum distillation unit (VI) for fuel hydrocarbons such as diesel (see Fig. 1). The feedstock for VPO contains a large amount of impurities such as sulfur, nitrogen, oxygen, metals and other materials that are not only unsuitable for the catalyst system. but also undesirable in the final product. These impurities are removed in the hydroprocessing reaction unit (R1) and the resulting treated VPO undergoes hydrocracking in the main reactor (R2), where most of it is converted to light hydrocarbons. The effluent from the reactor is first separated into a hydrogen rich gas.

and a hydrocarbon liquid. The gas is returned to the two reactors (R1 is fractionated by the ionizer fraction within the aforementioned feedstock, and the lighter products, the fitter and the ionizer.

hydrogen rich, recycled and R2) and a hydrocarbon fluid to oil products of various stages in series (Fs). Since it is virtually impossible to achieve a 100% conversion reaction, the portion that is not converted to diesel ends up as the bottom stream of the last

In fact, conventional fuel hydrocrackers are built so. that the pass-through efficiency (conversion achieved by a single pass through a hydrocracked reactor) is approximately 60

9581/177

The unconverted oil (NKO) is then either sent for storage as a semi-final product (this type of operation is called the single pass method) or recycled back to the main reactor (R2) for further cracking. to increase overall conversion (this type of operation is called the recycling method).

Since NKO is a mixture of highly saturated hydrocarbons, it has many desirable characteristics such as high viscosity index, which is one of the most important characteristics of lubricating oil - Table 1 shows the typical properties of VPO and NKO at a total conversion of 85% and a single pass conversion of 60%.

9581/177

Table 1

VPO and NKO properties

features VPO NKO API gravity 22 38 distillationx ° C / · - ΙΒΡχχ / 5% 260/340 350/370 10% / 20% 372/396 385/389 30% / 40% 415/434 410/422 50% / 60% 445/460 435/446 70% / 80% 475/492 458/474 90% / 95% 516/538 496/515 -FBPxxx / ^ yield 547 / 98.5 536 / 99.0 Hydrogen. % wt. 12.0 15.0 Nitrogen. ppm 800 4.0 Sulfur,% by weight 3.0 0.0009 Aniline temperature ° C 78 118 Freezing point ° C 33 38 Viscosity, centistock (cst) 40 ° C 49.9 19.3 @ 60 ° C 19.4 10.7 e 100 ° C 6:35 4.4 Viscosity index 64 143 Degree of satiety 31 98 % hydrocarbon,% by weight.

x ASTM D-1160. @ 760 mmHg xx Boiling point xxx Boiling point

From an economic point of view, it is preferable to use NKO for high-quality lubricating oil after further processing, such as dewaxing and stabilization, than to use it as an additive to fuel oil or to recycle it back to the hydrocracked reactor. Some refineries are known to produce lubricants

9581/177 oil of high viscosity index using NKO from fuel hydrocracker. Acted by the refinery, for example, it produces lubricating oil with VHVI (very high viscosity index) in its lubricating oil production plant by using NKO from its own single-pass fuel hydrocracker. The hydrocrack is located far from the lubricating oil factory. _from

However, the above-mentioned conventional method of producing lubricating oil from an NKO in a given plant presents several problems. NKO. produced by the hydrocracker unit, passes to the lubricating oil plant. Several existing units use this process. including vacuum distillation unit. units for dewaxing units, etc. and has a fairly low operational efficiency.

This is even more true for the above-mentioned refinery because the existing vacuum distillation unit designed for atmospheric treatment

It is even necessary to mix NKOs with heavier materials than the vacuum residue (VR) before. as it enters an existing vacuum distillation unit. For a better understanding of the prior art, we provide a description of a typical fuel hydrocracker with a recycling method. See also FIG. First

The atmospheric residue (AR) is supplied to the first vacuum distillation unit (VI). to form a vacuum gas oil (VPO). The VPO is then treated in the first reactor (R1). to extract the solution.

. is rather cumbersome was originally a residue (AR).

impurities were removed The resulting treated VPO reactor (R2) into a range of hydrocarbons are separated in as sulfur, nitrogen, oxygen and metals. is then hydrocracked in a second hydrocarbon product. These series of fractionators (Fs) for various light oil products and diesel.

However, not all of the cracked hydrocarbons are converted to diesel and lighter products. Much of the hydrocarbons remain unconverted. Most such unconverted oil is sent back to the second reactor (R2) for further conversion.

9581/177 the system must be deleted. to

However, in the case of a high end-point vacuum gas oil, heavy hydrocracking can gradually be stored in the internal recycle stream of the fuel hydrocracker. refractory hydrocarbons and condensed polynuclear aromatic compounds. Excess concentration of these compounds can then cause a sharp decrease in catalyst efficiency and poor product selectivity. To avoid such operational instability, a certain amount of unconverted oil is removed from it and to maintain an acceptable level of reaction activity. For this reason, the fuel hydrocracker recycles only a small amount of the product, which is recycled from the fractionators back to the first vacuum distillation unit CV1).

The reason for such a recirculation scheme is. to remove a portion of the refractory hydrocarbons and polynuclear aromatic compounds in the vacuum residue. Such a scheme also minimizes the amount of unconverted oil. which must be taken from the product that is returned from the fractionator. A typical level of recycling to the first vacuum unit is 15 to 25% of the total amount of unconverted oil.

In addition, unconverted high conversion fuel hydrocracker oil has an average viscosity in the range of 4.0 to too low a level to produce Neutral Lubricating Oil 150 high demand products and has a viscosity of 5.5 at 100 ° C. Therefore, a considerable amount

4.5 cst at 100 ° C.

Neutral lubricating oil 150 is one of up to 6.0 cst of unconverted oil in most existing refineries not used to produce lubricating oil, but is usually wasted on fuel oils.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to solve the above problems of the prior art and to provide a method for producing a raw material for high quality lubricating oil. this

9581/177 the invention will allow the efficient use of the desired portion of the unconverted oil for recycling in a fuel hydrocracker and thus utilize all means to the maximum extent possible.

The present invention is the first such approach to continuously produce a raw material for a high quality lubricating oil with a very high index, viscosity and low volatility from a fuel hydrocracker by a recycling method.

In accordance with a first aspect of the invention (as shown in Fig. 1), the above object can be achieved by providing a method for producing a high quality lubricating oil feedstock comprising vacuum distillation of atmospheric residue (AR) in a first vacuum distillation unit (VI), to form a vacuum gas oil (VPO), treating the vacuum gas oil in the first reaction unit (R1) to remove impurities, hydrocracking the treated vacuum gas oil in the second reaction unit (R2) to light hydrocarbons, using a series of fractionators (Fs) for separating the light oil products from the unconverted oil, not letting the above unconverted oil into the second vacuum distillation unit (V2) to produce a raw material for high-quality lubricating oil of the desired viscosity, and recycling the rest of the unconverted oil from the second vacuum distillation unit (V2) poison notices CR2).

In accordance with a second aspect of the present invention (shown in Fig. 2B), the above object can also be achieved by providing a method for producing a raw material for high quality lubricating oil, comprising: distilling the atmospheric residue (AR) under vacuum in a first vacuum distillation unit (VI). to form a vacuum gas oil (VPO), treating the vacuum gas oil in the first reaction unit (R1) into a plurality of light hydrocarbons, utilizing a series of fractional distillation (Fs) to separate the light oil products and uncorrected oil, impregnating a portion of this unconverted oil to the second vacuum

9581/177 to produce a feedstock for the desired viscosity, the remainder of the unconverted oil of fractional distillation (CFs) into the above distillation unit CV2), high quality lubricating oil and recycling from the above second reaction unit (R2).

Brief description of the drawings _of

Other objects and aspects of the present invention are illustrated by the following descriptions of its aspects with reference to the accompanying drawings, in which:

Fig. 1 is a block diagram. depicting conventional fuel hydrocracker. using the recycling method:

Fig. 2A is a block diagram illustrating a fuel hydrocracker and a method of producing a feedstock for a high quality lubricating oil according to a first aspect of the present invention: and

Fig. 2B is a block diagram illustrating a fuel hydrocracker and a method of producing a high quality lubricating oil feedstock according to a second aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In this section, a detailed description of aspects of the invention is given with reference to the above drawings.

Fig. 2A illustrates a fuel hydrocracker and a method of producing a feedstock for a high quality lubricating oil according to a second aspect of the present invention.

As shown in FIG. 2A, an atmospheric residue (ÄR) is charged to the first vacuum distillation unit (CV1) to produce a vacuum gas oil. which is subsequently subjected to a hydrogenation treatment in the first reaction unit (R1).

This is followed by a hydrogenation reaction that removes impurities such as sulfur, nitrogen, oxygen and metals from the VPO. The resulting treated vacuum gas oil enters the second reaction unit (CR2) where it is hydrocracked to a plurality of light hydrocarbons. These hydrocarbons are separated in a series of fractions

9581/177 distillation (Fs) to various light oil products including diesel.

However, a substantial part of the input hydrocarbons remains unconverted. All this unconverted oil is returned to the second vacuum distillation unit (V2) where the NKO is distilled. to provide a raw material for the high quality lubricating oil of the first aspect of the invention. While the oils of the desired viscosity are fractionated from the NKO in the second vacuum distillation unit (V2), they are subsequently dewaxed and stabilized. to form a lubricating oil, the remainder of the NKO is returned to the second reaction unit (R2).

Fig. 2B illustrates a fuel hydrocracker and a method of producing a feedstock for a quality lubricating oil according to a second aspect of the present invention. As shown therein, a portion of the MSW reaches the second vacuum distillation unit (V2). whereas the second portion of the NKO is returned to the second reaction unit (R2).

According to the present invention, further processing in the vacuum distillation unit (V2) is utilized. where a raw material for high quality lubricating oil having the desired viscosity grade can be produced. For example, 150 Neutral, a highly desirable viscosity grade, and 100 Neutral with a viscosity of from about 3.8 to about 4.2 cst at 100 ° C can be produced herein.

according to this temperature from

The second vacuum distillation tower (V2) is most preferably operated at about 300 to about 380 ° C and a pressure of about 20 to about 300 mmHg at the bottom of the tower.

about 60 to 70% of the second (R2) is recycled

Approximately 75 to 85% NKO (about 50 to return to the second reaction unit (R2))

Referring to FIG. of the input VPO reaction unit 56.7% of the VPO) via line 2 and (approximately 10 to 16.7% of this amount returns to the first vacuum to VPO) of the distillation unit (VI) via line 1.

According to the present invention, all or part of the NKO is provided

9581/177 duty of the second vacuum distillation unit (72), where the flux is tinned to the raw material for high quality lubricating oil of the desired viscosity. The lubricating oil feedstock constitutes approximately 15 to 25% of the total NKO content, which is equal to the amount returned to the first vacuum distillation unit (VI) in the conventional processing process (Fig. 1). The residue, which is approximately 75 to 85% of the total NKO content, is recycled to the second reaction unit (R2).

According to the invention, the ratio of total NKO from the fractional distillation process (Fs) to NKO recycled to the second reaction unit is preferably in the range of 1.05 to 2.0 L.

According to the present invention, the ratio of the NKO passing to the second vacuum distillation unit (V2) to the NKO recycled to the second reaction unit (R2) from the second vacuum distillation unit (V2) is preferably 1.05 to 4.0 L.

It follows from the foregoing description. according to the invention it is not necessary to return the NKO back to the first distillation unit (VI). The present invention is a first approach, i

which uses NKO from fuel hydrocracker to continuously produce a high quality lubricating oil with a very high viscosity index and low volatility, while recycling the unused portion of the NKO back to the hydrocracker reaction unit.

A preferred aspect of the present invention is described below with reference to specific examples.

Example 1

The vacuum gas oil with the properties described in Table 1 was treated in a hydroprocessing reaction unit (R1) at an hourly volumetric rate of 2.10 h ^-1 and treated with a catalyst, commercially available from the Nippon Ketjen Company in Japan, model HC-K, at an average a lower reactor temperature of 386.1 ° C and a reactor inlet pressure of 2.523 psig and using a hydrogen level of 5.720 SCF / BBL at the reactor inlet.

9581/177

The resultant unconverted oil vacuum gas, which in an hydrocracker reaction unit (R2) at an hourly volumetric rate of 1.26 h ^-1 and treated with a catalyst, commercially from UOP Incorporated in the USA, model HC-22, at a reactor bottom temperature of 393.8 ° C and the inlet psig using a hydrogen level of 7.520 oil was. then we describe together later, processed by the available average reactor pressure of 2500

SCF / BBL at reactor inlet.

All of the treated oil was then passed through a series of separations and fractional distillation (Fs). as shown in FIG. 2A to obtain diesel and lighter products and to provide 380 Table 1.

All unconverted oil properties according to vacuum unconverted oil were passed to a distillation unit (V2) in which the top temperature of the tower was 80 ° C, the bottom temperature of the tower 325 ° C. tower top pressure 75 mmHg and distilled, 100N distillate to give (ii) 8.3 LV%, and tower bottom pressure 150 mmHg, light distillate (i) 33.0 LV%, middle distillate (iii) 11.7 LV%, and bottom tower product (iv), 150N distillate 47.0 LV%.

From the above distillates, distillates of 100N to 150N are obtained in a volume of 25% of the unconverted oil entering the vacuum distillation unit (V2), i. 100N 5% and 150N 20%, and the residue is mixed and recycled to the hydrocracker reaction unit (R2).

The properties of the distillates are described in Table 2A.

Example 2

The vacuum gas oil having the properties of Table 1 was treated in a hydroprocessing reaction unit (R1) with an hourly volumetric rate of 2.10 h ^-1 and treated with a catalyst. commercially available from the Nippon Ketjen Company in Japan, model HC-K, at an average reactor bottom temperature of 385.9 ° C and a reactor inlet pressure of 2523 psig, using a hydrogen level of 5710 CSF / BBL at the reactor inlet.

9581/177

The resulting vacuum gas oil was then, together with the unconverted oil described later, treated in a hydrocracker reaction unit (CR2) at an hourly volumetric rate of 1.25 h ^-1 and treated with a catalyst commercially available from UOP Incorporated in USA, model HC-22 , at an average reactor bottom temperature of 394.1 ° C and a 2500 psig reactor inlet pressure using 7,500 SCF / EIBL hydrogen at the reactor inlet.

Subsequently, the treated oil went through a series of separations and fractional distillation (Fs) as shown in FIG. 2B to obtain diesel and lighter products therefrom and to provide 380 ° C + unconverted oil with the properties of Table 1.

Half of the C50 of the unconverted oil was transferred to the hydrocracker reaction unit (R2) and the other half (50 to the vacuum distillation unit CV2) in which the top tower temperature was 80 ° C, the bottom tower temperature 325 ° C, the top tower pressure 75 mmHg and the bottom pressure tower 150 mmHg, and distilled. to produce a light distillate (i) 32.9 LV%, 100N distillate C i i) 8.4 LV%, a middle distillate C i i) 11.8 LV% and a bottom product of the tower (iv), 150N distillate 46.9 LV%.

From the above distillates, distillates 100N and 150N are obtained in a volume of 50% of the unconverted oil entering the vacuum distillation unit (V2), i. 100N - 10% and 150N: 40%. and the residue is mixed and recycled to the hydrocracker unit (R2).

The properties of the distillates are described in Table 2B.

9581/177

Table 2A

Product features of the NKO vacuum distillation unit (V2) (for Example 1)

features easy desti lát 100N desti lát middle dest i lát 150N desti lát API Gravity 38.8 38.6 / · 38.4 37.8 Distillation * ° C - ΙΒΡχχ / 5LV% 278/289 377/405 341/408 424/437 10% / 30% 305/402 406/412 410/424 442/458 50% / 70% 405/414 421/431 434/447 471/493 90% / 95% 430/437 446/453 469/483 514/519 ΡΒΡχχχ 462 482 520 523 Viscosity, cst @ 60 ° C 7.63 8.50 9.26 13.89 @ 100 ° C 3:45 3.80 4.19 5.70 Viscosity index 143 154 179 172 Flash point (COC) ° C 143 220 192 248

Volatility. % 14.9 4.8

Average molecular

mass 347 387 403 456 Value Vat.son K 12.73 12.88 12.93 13.04 Freezing temperature 30.7 35.0

XX

XXX

ASTM D-1160, @ 760 mm / g. ° C, Initial boiling point Initial boiling point

9581/177

Table 2B

Product features of the NKO vacuum distillation unit (V2) (for Example 2)

features easy dest i lát 100N desti lát middle desti lát 150N desti lát API Gravity 38.9 38.6 / · 38.3 37.8 Distillationx ° C - ΙΒΡχχ / 5LV% 275/288 378/404 339/407 425/438 - 10% · 30% 306/402 406/413 411/424. 442/457 50% / 70% 404/413 420/431 433/446 476/495 90% / 95% 431/437 444/453 467/483 516/521 FBPxxx 463 484 518 525 Viscosity, cst @ 60 ° C 7.62 8:50 9.27 13.89 @ 100 ° C 3.43 3.80 4.14 5.70 Viscosity index 139 154 169 172 Flash point (CCOC) ° C 142 221 195 249

Volatility. % 15.0 5.0

Average molecular

mass 346 388 402 457 Value Vat.son K 12.72 12.88 12.92 13.04 Freezing temperature 30.9 36.1

x ASTM D-1160. @ 760 mmHg, ° C.

xx Boiling point xxx Boiling point

9581/177

As can be seen from the above examples and tables, according to the present invention, high quality 100N lubricating oil can be used to produce raw material for a 150N with a very high viscosity index and low volatility.

In addition, the removal of the heavy, polynuclear vacuum reaction diversion of a portion of the NKO prevents the accumulation of fusible hydrocarbons and condensed aromatic compounds, releases the capacity of the distillation unit (VI) and the hydrotreatment unit (R1), and allows the vacuum gas oil to be processed in oil. This proves that the present invention can utilize the device very efficiently.

Although we have disclosed a preferred aspect of the invention for illustrative purposes, those skilled in the art will recognize that various modifications, additions and substitutions may be employed without departing from the scope and spirit of the invention.

disclosed in the following claims.

Claims (8)

PATENT 1, A method of producing an oil feedstock by utilizing a high-quality lubricant of unconverted fuel hydrocracker oil, characterized in that it comprises the following steps: distilling the atmospheric residue in a vacuum gas oil distillation unit; hydroprocessing the vacuum gas oil in the first reaction unit (R1) to remove impurities therefrom; hydrocracking the treated vacuum gas oil in the second reaction unit (R2) to hydrocarbons; using a series of fractional distillations in the first (VI) to produce a vacuum to obtain light (Fs) to separate light oil products and unconverted oil; impregnating all the oil into a second vacuum to produce a feedstock for the desired viscosity; and recycling the remaining from the second vacuum distillation reaction unit (R2). of the above unconverted distillation unit (V2) to bring the high quality lubricating oil of the part of the unconverted oil unit (V2) to the other 2. The method of claim 1, wherein the UCA, the raw material for lubricating oil having the desired viscosity in the process of dewaxing and stabilization, while _(the remaining portion of unconverted oil from the second vacuum distillation unit (V2) is recycled to the second reaction unit (R2) . Method according to claim 1, characterized in that the second vacuum distillation unit (V2) is operated at a tower bottom temperature in the range of 300 to about 380 ° C at a tower bottom pressure in the range of about 20 to about 300 mmHcr. 4. The method of claim 1 wherein the ratio of total unconverted oil from distillation distillation (Fs) to the unconverted oil. recycled to another reaction j unit (R2) is in the range from 1.05 to 2.0: 1. / · 5. Method according to claim 1; c a with that ratio unconverted oil, passing to the second vacuum distillation unit (V2), to the unconverted oil recycled to the second reaction unit (R2), is in the range of 1.05 to 4.0: 1. 6. A process for producing a raw material for a high-quality lubricating oil, comprising the steps of: distilling the atmospheric residue (AR) under vacuum in the first vacuum distillation unit (VI) to form a vacuum gas oil (VPO); hydroprocessing the vacuum gas oil in the first reaction unit (R1) to remove impurities therefrom; hydrocracking the treated vacuum gas oil in the second reaction unit (R2) to obtain light hydrocarbons; utilizing a series of extractive distillations (Fs) to separate light oil products and unconverted oil; impregnating a portion of this unconverted oil into a second vacuum distillation unit (V2) to produce a feedstock of high quality lubricating oil of the desired viscosity; and recycling the remainder of the unconverted oil from the second vacuum distillation unit (V2) to the second reaction unit (R2), while the remainder of the unconverted oil from the above mentioned distillation distillation (Fs) is recycled to the above second reaction unit (R2). Method according to claim 6, characterized in - 17, in that the feedstock for the lubricating oil having the desired viscosity undergoes a dewaxing and stabilization process, while the remainder of the unconverted oil from the second vacuum distillation unit (V2) is recycled to the second reaction unit (R2). / · Method according to claim 6, characterized in that the second vacuum distillation unit (V2) is operated at a tower bottom temperature in the range of 300 to about 380 ° C at a tower bottom pressure in the range of about 20 to about 300 mmHg. Method according to claim G, characterized in that the ratio of unconverted oil from the distillation distillation (Fs) to unconverted oil recycled to second j : 1. reaction j units (R2) is a in the range from 1.05 to 4.0 10 method by claim 6. confesses č u j úCa sa t ý m, that ratio unconverted oil, passing to the second vacuum distillation unit (V2), to the unconverted oil recycled to the second reaction unit (R2), is in the range of 1.05 to 4.0 L.