JP2015512464A - Method for preparing residual base oil - Google Patents

Abstract

The present invention provides a method for preparing a residual base oil, which comprises the following steps: (a) providing a waxy raffinate that is a mineral bright stock; (b) in step (a). In step (b), combining a waxy raffinate, a bright mineral mineral stock, with a Fischer-Tropsch derived base oil, a residual oil that has been catalytically dewaxed, thereby obtaining a mixture; Solvent dewaxing the resulting mixture, thereby obtaining a residual base oil, wherein a waxy raffinate that is a mineral bright stock and a catalyst dewaxed residual oil in step (b). The weight ratio with the Tropsch derived base oil ranges from 75:25 to 35:65. In another aspect, the present invention provides a residual base oil obtainable by this method. [Selection figure] None

Description

  The present invention relates to a process for preparing a residual base oil and to the residual base oil obtained by this process.

It is known to use Fischer-Tropsch derived base oils of high viscosity (typically 20-25 mm ² / s) to improve the lubricating properties (eg pour point and cloud point) of base oils. Yes. High viscosity base oils, also known as bright stock base oils, derived from Fischer-Tropsch synthesis, typically have haze due to the presence of small amounts of microcrystalline wax particles. Often exhibits a hazy appearance.

WO (International Publication) 2007/003623 is based on a base oil component of a paraffinic base oil having a viscosity of 8 to 25 mm ² / s at 100 ° C., and 40% to 99% based on the total weight of the base oil blend. Disclosed is a method for preparing a bright stock base oil formulation comprising a quantity of mineral-derived residue and deasphalted oil components. In WO 2007/003623, a precursor component of a Fischer-Tropsch derived paraffinic base oil produces a hazey Fischer-Tropsch derived paraffinic base oil component. The amount of wax present in the Fischer-Tropsch derived paraffinic base oil component is not sufficient to dewax the Fischer-Tropsch derived paraffinic base oil component in an efficient manner. Thus, the haze-Fischer-Tropsch derived paraffinic base oil component is mixed with mineral-derived residual oil at temperatures above 50 ° C. to obtain a clear oil blend.

WO (International Publication) 2007/003623

  It is an object of the present invention to provide a more efficient method for preparing a clear and bright residual base oil.

  A further object of the present invention is to provide an alternative method for preparing a clear and transparent residual base oil.

  Another object of the present invention is to prepare a clear and clear residual base oil using a large proportion of high viscosity Fischer-Tropsch derived base oil.

The above objects or other objects are achieved by providing a method for preparing a residual base oil according to the present invention, which method comprises at least the following steps:
(A) preparing a mineral bright stock waxy raffinate, which is a mineral bright stock;
(B) a catalytically dewaxed residual Fischer-Tropsch derived base oil which is a residual oil obtained by catalytic dewaxing of the waxy raffinate which is a mineral bright stock prepared in step (a); Together, thereby obtaining a mixture; and (c) solvent dewaxing the mixture obtained in step (b), thereby obtaining a residual base oil.

  Surprisingly, in accordance with the present invention, solvent dewaxing is performed on a mixture comprising a waxy raffinate that is a mineral bright stock and a Fischer-Tropsch derived base oil that is a catalyst dewaxed residue. It has been found that the existing haze can be easily removed.

  In order to operate the solvent dewaxing process in an optimal manner, at least 5 in a mixture of mineral bright stock waxy raffinate and catalytic dewaxed residue Fischer-Tropsch derived base oil. It has been found that weight percent wax is required. The amount of wax present only in the Fischer-Tropsch derived base oil, which is the catalyst dewaxed residue, is not sufficient to individually dewax the base oil in an efficient manner. The amount of wax present in the catalyst dewaxed residue, Fischer-Tropsch derived base oil, is 0.1 based on the total amount of catalyst dewaxed residue, Fischer-Tropsch derived base oil. Less than% by weight.

  A sufficient amount (at least 5% by weight) of this mixture is obtained by solvent dewaxing a mixture containing the mineral bright stock waxy raffinate and the catalyst dewaxed residue Fischer-Tropsch derived base oil. %) Wax avoids the difficulty of removing haze resulting from only the Fischer-Tropsch derived base oil, which is the catalyst dewaxed residue, thereby increasing efficiency.

  A further advantage of the present invention is that high viscosity Fischer-Tropsch derived base oils can be used in large quantities in the mixture, yet a clear, clear, high viscosity base oil is obtained.

  Another advantage of the present invention is that it provides a clear and transparent residual base oil with high viscosity, low pour point and low cloud point.

FIG. 1 schematically shows the processing system of the method according to the present invention.

  In step (a) of the method according to the present invention, a waxy raffinate which is a mineral bright stock is prepared. Various methods are known in the art for preparing waxy raffinates that are mineral bright stocks.

Suitably, a waxy raffinate that is a mineral bright stock is prepared using the following process:
(Aa) preparing a mineral derived vacuum residue;
(Bb) performing a deasphalting step on the mineral-derived vacuum distillation residue, thereby obtaining a deasphalted oil; and (cc) solvent extracting the deasphalted oil, thereby Obtaining a residual aromatic extract and a waxy raffinate which is a mineral bright stock.

  In the step (aa), a mineral-derived vacuum distillation residue is prepared. The mineral-derived vacuum distillation residue prepared in step (aa) may be a residual bottom fraction of a crude oil feed vacuum distillation. A preferred characteristic of the mineral-derived vacuum distillation residue is that 90% by weight boils above 500 ° C, more preferably 90% by weight boils above 520 ° C.

  In the step (bb), the deasphalting step for the mineral-derived vacuum distillation residue is performed to obtain a deasphalted oil. Deasphalted oil is the product of the deasphalting process, in which asphalt is removed from the mineral-derived vacuum distillation residue. The process of deasphalting is well known and is described, for example, in “Processing of Lubricating Base Oils and Waxes” (Avilino Sequeira, Jr., Marcel Dekker, Inc, New York, 1994, ISBN 0-8247-9256-4). ~ Page 80. Typically, the deasphalting process uses a light hydrocarbon liquid solvent (eg, propane) for the asphalt compound. A preferred characteristic of the deasphalted oil is that 90% by weight boils above 470 ° C, more preferably 90% by weight boils above 490 ° C.

  In step (cc), the deasphalted oil is subjected to solvent extraction, thereby obtaining a waxy raffinate that is a residual aroma extract and a mineral bright stock.

  The deasphalted oil is subjected to a solvent extraction process to remove some of the aromatic compounds. The process of solvent extraction is known in the art and will therefore not be described in detail here. A typical solvent extraction process is described, for example, in "Processing of Lubricating Base Oils and Waxes" (Avilino Sequeira, Jr., Marcel Dekker, Inc, New York, 1994, ISBN 0-8247-9256-4). It is described in the chapter.

  Normally, following solvent extraction of the deasphalted oil, the solvent is removed from the mineral bright stock waxy raffinate and the wax is the bright stock of most aromatics and some dissolved minerals. Residual aroma extract containing raffinate in the form of some wax and some wax is sent to the recovery unit. This process is described, for example, in US Pat. No. 4,592,932.

  The waxy raffinate, the mineral bright stock prepared in step (a), is the resulting extracted deasphalted oil phase, obtained in step (cc), but mainly unsaturated carbonized. Contains hydrogen molecules. Suitably, the amount of unsaturated hydrocarbon molecules is between 50 and 60% by weight, based on the total amount of waxy raffinate that is the mineral bright stock.

Suitably, the waxy raffinate that is the mineral bright stock provided in step (a) has a kinematic viscosity of 200-700 mm ² / s at 40 ° C. according to ASTM D-445, preferably 300-600 mm. ² / s, more preferably 400 to 600 mm ² / s, and most preferably has a kinematic viscosity of 500 to 600 mm ² / s.

Also, the kinematic viscosity at 100 ° C. of the waxy raffinate, a mineral bright stock, is suitably 20-50 mm ² / s, preferably 30-50 mm ² / s, and more preferably 30 according to ASTM D-445. ˜40 mm ² / s. Typically, the viscosity index of a waxy raffinate, a mineral bright stock, is between 50 and 150, preferably between 70 and 120, more preferably between 80 and 100.

  In step (b), the waxy raffinate that is the mineral bright stock prepared in step (a) is combined with a Fischer-Tropsch derived base oil that is the catalyst dewaxed residue, thereby obtain.

  In an alternative embodiment of the process according to the invention, part of the deasphalted oil obtained in step (b) is not subjected to the solvent extraction step (cc) and is a catalyst dewaxed residual oil. Combined with a Tropsch derived base oil, thereby obtaining a mixture.

  Suitably, the Fisher wherein at least 20% by weight of the deasphalted oil, preferably at least 30% by weight of the deasphalted oil, and more preferably at least 50% by weight of the deasphalted oil is catalyst dewaxed residual oil. Combined with a Tropsch derived base oil, thereby obtaining a mixture.

  The Fischer-Tropsch derived base oil, which is the catalyst dewaxed residue used in step (b), is derived from the Fischer-Tropsch process. Fischer-Tropsch derived base oils are known in the art. The term “Fischer-Tropsch derived” means that the base oil is a synthetic product of, or derived from, a Fischer-Tropsch process. A Fischer-Tropsch derived base oil may be referred to as a GTL (gas to liquid) base oil.

  Solvent dewaxing of the catalyst dewaxed residual base oil would be extremely difficult due to the very small amount of wax. More importantly, however, the wax will have a “chewing gum” consistency, which makes it very difficult to filter with a filter cloth. This "chewing gum" consistency is caused by a catalyst dewaxing process, which is necessary to obtain a Fischer-Tropsch derived high viscosity base oil having the desired pour point. The Fischer-Tropsch product to obtain catalyst dewaxed residual base oil has an unfavorable pour point and is heavy and could not be easily exported from the Fischer-Tropsch manufacturing facility.

  The preparation of Fischer-Tropsch derived base oil, the catalyst dewaxed residue used in step (b), is described, for example, in WO 2007/003623 and WO 2007/003617.

  The catalyst dewaxed Fischer-Tropsch derived base oil of the present invention typically has a carbon of up to about C65, typically in the range of at least C20 and below C65, and at least 0.001% by weight. A heavy base oil component containing no more than 5% by weight wax component, typically no more than 1% by weight, suitably no more than 0.1% by weight wax component. Typically, the amount of wax component present in the Fischer-Tropsch derived base oil, a catalyst dewaxed residue, depends on the pour point stringency.

  It can be seen that the Hazy catalyst dewaxed residue of the present invention, Fischer-Tropsch derived base oil, is at least partially or completely opaque at ambient temperature. Thus, the Fischer-Tropsch derived base oil, the catalyst dewaxed residue used in the present invention, has additional heavy components (e.g., waxes) sufficient to give a visible haze to the base oil appearance. ) Will be apparent to those skilled in the art. Typically, the amount of wax that provides visible haze is between 0.01% and 0.1% by weight based on the total amount of Fischer-Tropsch derived base oil, the catalyst dewaxed residue. It is. Accordingly, the base oils of the present invention will generally not be described as “clear” or “bright”.

Suitably, the Fischer-Tropsch derived base oil, the catalyst dewaxed residue used in step (b), typically has a kinematic viscosity greater than 80 mm ² / s at 40 ° C. according to ASTM D-445. Suitably with a kinematic viscosity greater than 100 m ² / s. Typically, the kinematic viscosity at 40 ° C. of a catalyst dewaxed Fischer-Tropsch derived base oil according to the present invention is less than about 300 mm ² / s.

Also, the kinematic viscosity at 100 ° C. of the Fischer-Tropsch derived base oil according to ASTM D-445 is 12-50 mm ² / s, preferably 15-35 mm ² / s, more preferably 18-30 mm ² / s, and most Preferably it is 18-25 mm < ² > / s.

  Fischer-Tropsch derived base oil which is a catalyst dewaxed residue preferably has a pour point of less than 0 ° C., more preferably less than −5 ° C., and most preferably less than −10 ° C. according to ASTM D-5950. Has a point.

  Typically, a haze paraffinic base oil has a cloud point of 15 ° C. or higher. Preferably, the catalyst dewaxed residue, Fischer-Tropsch derived base oil, has a cloud point higher than 15 ° C. according to ASTM D-5950, more preferably higher than 20 ° C., more preferably 25 It has a cloud point higher than 0C and most preferably higher than 30C.

  Suitably, the mixture obtained in step (b) comprises from 10 to 80% by weight of Fischer-Tropsch base oil, which is a catalyst dewaxed residual oil, preferably 20 to 70% by weight, more preferably 25 to 65% by weight. % Is included.

  Preferably, the weight ratio of the mineral bright stock waxy raffinate to the catalyst dewaxed residual Fischer-Tropsch base oil in step (b) of this process is from 75:25 to 35:65. A range of 65:35 to 35:65, most preferably 55:45 to 35:65.

  The mixture obtained in step (b) will typically contain a fraction boiling 50% above 450 ° C, preferably a fraction boiling 50% above 550 ° C. It is such a high boiling fraction, which will be a viscous base oil.

  Typically, the mixture obtained in step (b) will contain a fraction that boils 90% below 820 ° C.

  The wax content in this mixture is preferably less than 20% by weight, more preferably less than 10% by weight. The lower limit is preferably more than 4% by weight.

  In step (c), a solvent dewaxing step is performed on the mixture obtained in step (b), thereby obtaining a residual base oil.

  Solvent dewaxing processes are known in the art and are therefore not described in detail here. A typical solvent dewaxing process is described, for example, in Chapter 7 of "Lubricating Base Oil and Wax Processing" (Avilino Sequeira, Jr., Marcel Dekker, Inc, New York, 1994).

  In a preferred embodiment, the process according to the invention comprises the further step of separating heteroatoms from the residual base oil obtained in step (c).

  Preferably, the residual base oil obtained in step (c) contains sulfur and nitrogen compounds, which are included in an amount of less than 50 ppmw, more preferably less than 20 ppmw, more preferably less than 10 ppmw. Most preferably, it contains sulfur and nitrogen at levels generally below the detection limit, which limits are currently at 5 ppm for sulfur and nitrogen using, for example, an X-ray test for measurement or an Antek nitrogen test. It will be 1 ppm. However, sulfur may be introduced through the use of a sulfurized hydrocracking (or hydrodewaxing) catalyst and / or a sulfurized catalytic dewaxing catalyst. If desired, a final finishing treatment may be performed to separate the sulfur and nitrogen compounds from the residual base oil. Examples of suitable finishing treatments are so-called sulfuric acid treatment processes, hydrofinishing or hydrogenation processes and adsorption processes. Sulfuric acid treatment is described, for example, in chapter 6, pages 226-227 of the general textbook "Processing of lubricating base oils and waxes" (Avilino Sequeira, Jr., Marcel Dekker, Inc, New York, 1994). ing.

  The hydrofinishing is suitably carried out at a temperature between 180 and 380 ° C. with a total pressure between 10 and 250 bar, and preferably more than 100 bar, more preferably between 120 and 250 bar. . WHSV (weight hourly space velocity) is in the range of 0.3-2 kg (kg / l.h) of oil per hour per liter of catalyst.

  In a further aspect of the invention, a residual base oil obtainable by the method according to the invention is provided.

This haze-free residual base oil preferably has a kinematic viscosity of 12-50 mm ² / s at 100 ° C. according to ASTM D-445, preferably 15-35 mm ² / s, more preferably 18-30 mm ² / s. And most preferably will have a kinematic viscosity of 18-25 mm ² / s.

  The viscosity index of the residual base oil is preferably greater than 95, preferably greater than 100.

  The pour point of the residual base oil according to ASTM D-5950 is less than -5 ° C, preferably less than -10 ° C, and most preferably less than -15 ° C.

  Base oil without haze can also be determined by its cloud point. The residual base oil preferably has a cloud point of less than -10 ° C, more preferably less than -15 ° C, and most preferably less than -20 ° C according to ASTM D-5950.

  FIG. 1 schematically shows the processing system of the method according to the present invention.

  For purposes of this description, a single reference number will be assigned to a line as well as the flow carried within that line.

  The processing scheme is generally referred to using the reference numeral 1.

  A mineral-derived vacuum distillation residue 20 is recovered from the crude oil supply 10 by vacuum distillation in the vacuum distillation apparatus 2. The mineral-derived vacuum distillation residue 20 is deasphalted in the reactor 3, thereby obtaining a deasphalted oil 30. In the reactor 4, a residual aroma extract 40 and a waxy raffinate 50 which is a mineral bright stock are extracted from the deasphalted oil 30. Residual aroma extract 40 and solvent are sent as flow 40 from reactor 4 to recovery unit 5. A stream containing a Fischer-Tropsch derived base oil 60, a haze-catalyzed dewaxed residue, is combined with a waxy raffinate 50, a mineral bright stock, upstream of the reactor 6. The combined streams are solvent dewaxed to yield a residual base oil 70 and a waxy product (mixed slack wax). Sulfur and nitrogen are separated from the residual base oil 70 in the form of hydrocarbon compounds in the reactor 7 by a final finishing treatment.

  The invention is described below with reference to the following examples, which are not intended to limit the scope of the invention in any way.

Example 1
Preparation of a waxy raffinate, a mineral bright stock A waxy raffinate, a mineral bright stock, was obtained from Shell Parnis Refinery (Pernis, The Netherlands). This mineral bright stock, waxy raffinate, was prepared by performing a deasphalting step on a mineral-derived vacuum distillation residue (a high sulfur middle east crude, such as Arabian light). The resulting deasphalted oil was analyzed in furfural using an average solvent to new feed ratio of 3.8 wt / wt (minimum 2.4 wt / wt, max 6.3 wt / wt). Extraction was performed, thereby obtaining a residual aroma extract and a waxy raffinate that was a mineral bright stock. Processes for furfural solvent extraction are known in the art, for example, “Lubricating Base Oil and Wax Processing” (Avilino Sequeira, Jr., Marcel Dekker, Inc, New York, 1994, ISBN 0-8247-9256- It is described in Chapter 5 of 4). The properties of the waxy raffinate that is the bright stock of the resulting mineral are listed in Table 1.

Preparation of Fischer-Tropsch derived base oil which is a catalyst dewaxed residue According to the method described in Example 1 of WO2007 / 003623, a Fischer-Tropsch derived base oil which is a catalyst dewaxed residue is obtained. Obtained. Properties of the resulting catalyst dewaxed residual oil are listed in Tables 2 and 3.

Residual base oil preparation Residual Fischer-Tropsch derived base oil and mineral bright stock waxy raffinate in various ratios (see Table 4: Experiments A, B, C and D) at 60 ° C. Several mixtures were prepared by mixing together at 15 minutes.

  The resulting mixture was subjected to the usual solvent dewaxing process as follows.

  A measured amount (120 g) of the resulting mixture was dissolved in a specific amount of toluene and methyl ethyl ketone mixture (50/50) at a ratio of 4/1. By cooling the solution to the required dewaxing temperature (−20 ° C.), precipitating the slack wax and filtering using a lined filter paper (Whatman Number 41, Catalog Number: 14491090, Whatman Division of GE Health Care) The liquid phase was separated. The solvent was removed from the resulting residual base oil under reduced pressure of less than 1000 ppm.

  The properties of the obtained residual base oil are listed in Table 5.

The results in Study Table 5 show that the solvent dewaxed mixture obtained in Experiments AD according to the present invention is a clear and transparent residual base oil. Furthermore, by adding a large proportion of the Fischer-Tropsch derived base oil, which is the catalyst dewaxed residue, into the mixture (see, eg, Experiment D), a clear and transparent base oil is also obtained. Obtained. In addition, the catalyst dewaxed residue is obtained by adding a large proportion of the catalyst dewaxed residue, Fischer-Tropsch base oil, to the mixture (see experiments AD in Table 4). There is an improvement in the pour point of the residual base oil (see Table 5) compared to the pour point of the Fischer-Tropsch derived base oil (see Table 2).

  DESCRIPTION OF SYMBOLS 1 Treatment system, 2 Vacuum distillation apparatus, 3 Reactor, 4 Reactor, 5 Recovery apparatus, 6 Reactor, 7 Reactor, 10 Crude oil supply, 20 Mineral-derived vacuum distillation residue, 30 Deasphalted oil, 40 Residual fragrance extract, 50 waxy raffinate, 60 Fischer-Tropsch derived base oil, 70 residual base oil, 80 waxy product.

Claims (12)

A method for preparing a residual base oil comprising the following steps:
(A) preparing a waxy raffinate that is a mineral bright stock;
(B) combining the waxy raffinate, which is the mineral bright stock prepared in step (a), with the Fischer-Tropsch derived base oil, which is the catalyst dewaxed residue, thereby obtaining a mixture; and (C) solvent dewaxing the mixture obtained in step (b), thereby obtaining a residual base oil;
Wherein the weight ratio of the waxy raffinate that is the mineral bright stock in step (b) to the Fischer-Tropsch derived base oil that is the catalyst dewaxed residual oil is 75:25 to 35: Said method, ranging up to 65. The waxy raffinate, a mineral bright stock, has the following steps:
(Aa) preparing a mineral-derived vacuum distillation residue;
(Bb) performing a deasphalting step on the reduced pressure distillation residue derived from mineral, thereby obtaining a deasphalted oil; and (cc) performing a solvent extraction on the deasphalted oil, whereby a residual aroma extract And obtaining a waxy raffinate that is a mineral bright stock;
The method of claim 1, prepared using Waxy raffinate is bright stock mineral in step (a), 20 to 50 mm ² / s at 100 ° C., preferably from 30 to 50 mm ² / s, more preferably has a kinematic viscosity of 30 to 40 mm ² / s The method according to claim 1 or 2. Fischer-Tropsch base oil, the catalyst dewaxed residue in step (b), is 12-50 mm ² / s, preferably 15-35 mm ² / s, more preferably 18-30 mm ² / s, at 100 ° C., and 4. A method according to any of claims 1 to 3, most preferably having a kinematic viscosity of 18 to 25 mm < ² > / s.   The Fischer-Tropsch derived base oil, the catalyst dewaxed residue in step (b), has a pour point of less than 0 ° C, preferably less than -5 ° C, more preferably less than -10 ° C. Item 5. The method according to any one of Items 1 to 4.   Fischer-Tropsch derived base oil, the catalyst dewaxed residue in step (b), has a cloud point higher than 15 ° C, preferably higher than 20 ° C, more preferably higher than 25 ° C. And most preferably, it has a cloud point higher than 30 ° C.   The mixture obtained in step (b) comprises 10 to 80%, preferably 20 to 70%, more preferably 25 to 65% by weight of Fischer-Tropsch derived base oil which is a catalyst dewaxed residual oil. The method according to claim 1, comprising:   Residual base oil obtained by the method according to claim 1. 9. A kinematic viscosity at 100 [deg.] C. of 12-50 mm < ² > / s, preferably 15-35 mm < ² > / s, more preferably 18-30 mm < ² > / s, and most preferably 18-25 mm < ² > / s. Residual base oil.   Residual base oil according to claim 8 or 9, having a viscosity index greater than 95, preferably greater than 100.   The residual base oil according to any of claims 8 to 10, having a pour point of less than -5 ° C, preferably less than -10 ° C, more preferably less than -15 ° C.   12. Residual base oil according to any of claims 8 to 11, having a cloud point of less than -10 <0> C, preferably less than -15 <0> C, more preferably less than -20 <0> C.

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