JP2954392B2 - Method for producing high viscosity index lubricating oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing a high viscosity index lubricating oil having a viscosity index of at least 125 from a petroleum wax feed having a paraffin content of at least 40% by weight.

[0002]

2. Description of the Related Art Conventionally, a mineral oil-based lubricating oil is obtained by fractionating a paraffinic crude oil under atmospheric pressure, then fractionating it under reduced pressure, and performing distillation fractionation (neutral oil) and residue fractionation. Which were produced by a sequential separation performed in a petroleum refining process.
After deasphalting and severe solvent treatment, the residual fraction can also be used as a lubricating base oil, usually called bright stock. Conventionally, after solvent extraction to remove the low viscosity index (VI) component, the neutral oil is dewaxed by a solvent or catalytic dewaxing process to the desired pour point and then dewaxed lubrication. The oil feedstock is hydrofinished to improve stability and remove color. This conventional method relies on the selection and use of a crude stock, which typically has paraffin properties, that produces the desired lubricating oil fraction with the desired quality in the appropriate amount. However, the range of crude oil sources that can be tolerated by lubricating oil hydrocracking processes that can utilize marginal or poor quality crudes that usually have higher aromatics content than the best paraffinic crudes Can be extended. The well-established lubricating oil hydrocracking process in the petroleum refining industry is based on initial hydrogenation at elevated pressures in the presence of a bifunctional catalyst that performs partial saturation and ring opening of aromatic components present in the feedstock. A chemical decomposition step. The hydrocracked product is then dewaxed to reach the target pour point. The product from the initial hydrocracking step with paraffinic properties contains components with rather high pour points that need to be removed in the dewaxing step.

[0003] In the current trend of automotive engine design, operating temperatures are increasing with increasing engine efficiency, and high operating temperatures require lubricating oils of successfully high quality. One of the requirements is a high viscosity index (V
I), the effect of high operating temperatures on the viscosity of the engine lubricating oil is reduced. High VI values have been conventionally achieved by the use of VI improvers, such as polyacrylates, but the degree of improvement that can be achieved in this way is limited. In addition, VI improvers tend to degrade at the effects of high shear rates and high temperatures that occur in engines, and the high stress conditions that occur in high efficiency engines can result in rapid degradation of oils using significant amounts of VI improvers. Occurs. Thus, there is a continuing need for automotive lubricating oils based on high viscosity index liquids that are stable to the high temperature, high shear rate conditions encountered in current engines.

[0004] Synthetic lubricating oils produced by the polymerization of olefins in the presence of certain catalysts have good VI values,
It is expensive when prepared by conventional synthetic methods and usually requires expensive starting materials. Accordingly, there is a need for producing high VI lubricating oils from mineral feedstocks with technologies comparable to those currently used in petroleum refining.

[0005] In theory as well as in practice, lubricating oils should have highly paraffinic properties. This is because paraffin has a preferred combination of low viscosity and high viscosity index. N-paraffins and slightly branched paraffins, such as n-methyl paraffin, provide unacceptably high pour points in lubricating oil base stocks, and are therefore waxy that can be removed during the dewaxing operation in the conventional refining processes described above. Substance. However, it is possible to treat the waxy feed in such a way that it retains many of the benefits of paraffin properties while eliminating undesirable pour point properties. A harsh hydrotreating process for producing high viscosity index lubricating oils has been developed by S. Bull et al.
Devlopments in Lubricatio
n), PD 19 (2), pp. 221-228, in which a waxy feed such as waxy distillate, deasphalted oil and crude wax is subjected to a two-step hydrotreating process. Is done. In this treatment method, the initial hydrotreating unit is operated under the high temperature
Processing the feedstock in a block operation in the process,
Undesired aromatic compounds are selectively removed by hydrocracking and hydrogenation. The second step operates under fairly mild conditions at the lower temperatures where hydrogenation is preferred, adjusting the total aromatics content and affecting the distribution of aromatic species in the final product. In the next redistillation step, the viscosity and flash point of the base oil are adjusted by atmospheric distillation. The pour point of the final base oil is then adjusted by dewaxing in a solvent dewaxing (MEK-toluene) unit.
The crude wax removed from the dewaxing agent is reprocessed to produce a high viscosity index base oil.

[0006] This type of process using a waxy feedstock for hydrocracking with an amorphous bifunctional catalyst such as nickel / tungsten on alumina or silica / alumina is disclosed, for example, in British Patent Application Publication No. One,
Nos. 429,494, 1,429,291 and 1,4
No. 93,620, and U.S. Pat.
No. 0,273, No. 3,776,839, No. 3,794,5
No. 80 and 3,682,813.
In the process described in GB-A-1 429 494, the crude wax produced by dewaxing of the waxy feed was 2000 psig (138
Hydrocracking with a bifunctional hydrocracking catalyst at a hydrogen pressure of 81 kPa) or higher, followed by dewaxing of the hydrocracking product to obtain the desired pour point. It is described that the dewaxing is preferably carried out by a solvent method by reusing the separated wax in the hydrocracking step.

[0007] In this type of process, the hydrocracking catalyst is typically a bifunctional catalyst containing a hydrogenation metal component on a non-crystalline acidic support. The metal component may be a combination of a base metal, a combination of one metal selected from the iron group (Group VIII) of the periodic table and one metal selected from Group VIB, for example, nickel and molybdenum or tungsten. It is a combination of British Patent No. 1,350,
No. 257, No. 1,342,499 and No. 1,440,2
30, French Patent Nos. 2,123,235 and 2,124,138, and European Patent No. 19
As described in US Pat. No. 9,394, modifying agents such as phosphorus or boron may be included. Boron may be used as a modifier, as described in GB 1,440,230. British Patent 1,39
No. 0,359, the activity of the catalyst is:
It can be increased by using fluorine, that is, by adding fluorine to the catalyst in the form of a suitable fluorine compound during its manufacture or by fluorinating in situ during the operation of the process.

[0008] Although it has been shown that high viscosity index lubricating oils can be produced by processes that use non-crystalline catalysts for the treatment of waxy feeds, they have limitations. Best of all, the process requires significant dewaxing performance to produce the feedstock and dewax the hydrocracking products to the desired pour point. The reason for this is that while amorphous catalysts are effective at saturating aromatic hydrocarbons under the high pressure (about 2000 psig) conditions typically used, the activity and selectivity for isomerization of paraffin components is Not as high as required; therefore, rather linear paraffins,
To the extent that the product pour point specification is well met, the waxiness with a rather high viscosity index but low pour point properties cannot be isomerized to lower isoparaffins. Therefore, the waxy paraffin passing through the unit must be removed and reused during the next dewaxing step, thus reducing the capacity of the unit. The limited isomerization activity of the amorphous catalyst limits the single pass yield to a value of about 50% or less, with a corresponding wax conversion of about 30-60%. However, higher yields significantly increase the efficiency of the process. Product VI is also limited due to isomerization activity, typically to about 145 at 0 ° F (-18 ° C) pour point in a single pass operation. Temperature requirements for amorphous catalysts are also significantly higher, at least as compared to zeolite catalysts, and are typically about 7
00-800 ° F (371-427 ° C).

Another method of upgrading a waxy feedstock to a high VI lubricating oil base stock is disclosed in US Pat.
Nos. 19,788 and 4,975,177. Here, a waxy feed, typically a waxy gas oil, a crude wax or a deoiled wax, is hydrotreated with a highly siliceous zeolite β catalyst.
As described in U.S. Pat. No. 4,419,220, zeolite beta is known to be very effective in the isomerization of paraffins in the presence of aromatic hydrocarbons, and its ability is United States Patent 4,91
Nos. 9,788 and 4,975,177 have been used effectively to optimize product yield and viscosity characteristics. The zeolite beta catalyst isomerizes the high molecular weight paraffins contained in the rear end of the feedstock into less waxy materials and minimizes the decomposition of these components into materials that boil outside the lubricating oil range. The waxy paraffins at the leading end of the feed are removed in a subsequent dewaxing step, solvent or catalytically, to achieve the target pour point. The combination of the paraffin hydroisomerization process and the subsequent selective dewaxing process at the leading end of the feed can achieve higher product VI than these processes alone, and in addition, the process can be implemented on demand. And can be optimized for yield efficiency or for VI efficiency.

Although this zeolite catalyst process has been found to be very effective in handling highly paraffinic feedstocks, the high zeolite beta catalyst combined with a low ability to remove low quality aromatic components is used. Isomerization selectivity tends to limit the application of this process to feedstocks containing significantly lower amounts of aromatic hydrocarbons. Aromatic hydrocarbons and other polycyclics are not easily attacked by zeolites, so they are
It passes through the process and remains in the product, lowering the VI. Lubricating oil yields also tend to be constrained by low wax isomerization selectivity at low conversions and by wax cracking outside the lubricating oil boiling range at high conversions. Maximum lubricating oil yields are typically obtained in a conversion range of 20-30% by weight (650 ° F. + conversion). Therefore, it is preferred to increase the isomerization selectivity and at the same time decrease the hydrocracking selectivity in order to improve the lubricating oil yield while maintaining a high VI value of the product.

Thus, in summary, the process using an amorphous catalyst can be considered to be inferior in single pass conversion and overall yield. Amorphous catalysts are fairly non-selective for paraffin isomerization, but have a high activity for cracking, the overall yield remains low and the requirements for dewaxing are high. In contrast, zeolite catalyzed processes can achieve high yields. Because zeolites have a very high selectivity for paraffin isomerization in the presence of polycyclic components, the aromatic hydrocarbons are poor at the moderate hydrogen pressures used in the process. And operation is constrained by varying selectivity factors of the zeolite at various conversion levels.

[0012]

SUMMARY OF THE INVENTION A high quality lubricating oil feedstock can be obtained in excellent yields by operating with feedstocks of various compositions to produce low pour point products with very high viscosity indices. It has been found that high quality, high viscosity index lubricating oils can be readily produced by a wax hydroisomerization process using a controlled low acidity zeolite catalyst at high pressure.
The viscosity index of the product depends on the composition of the feed, especially its wax content, but with a preferred crude wax feed a high viscosity index, typically above about 140, usually between 140 and 155, can be obtained; A value of 147 is typical. Higher yields compared to processes using amorphous catalysts due to the effect of the process of converting waxy paraffins, primarily linear and nearly linear paraffins, to lower waxy high viscosity index isoparaffins Extremely low dewaxing requirements.

In accordance with the present invention, a process for producing a high viscosity index lubricating oil having a viscosity index of at least 125 from a petroleum wax feed having a paraffin content of at least 40% by weight comprises hydrogen at a hydrogen partial pressure of at least 6991 kPa (1000 psig). In the presence, the presence of a noble metal hydrogenation component on a porous zeolite support, in the presence of a low acid zeolitic isomerization catalyst having an alpha value not exceeding 20, reduces the waxy paraffins present in the feed to a less waxy nature. Isomerizing to isoparaffins. The feedstock is typically a petroleum wax having a wax content of at least 60% by weight and an aromatic content of 5 to 20% by weight, for example an aromatic content of 8%.
-12% by weight of crude wax. Deoiled wax and solvent refined raffinate can also be used as raw materials.

The isomerization catalyst preferably comprises a zeolite beta isomerization catalyst whose alpha value does not exceed 10, advantageously does not exceed 5. Suitable catalysts are boron-containing zeolite beta, where boron is present as a framework component of zeolite beta. Zeolites are usually complexed with a matrix material, and in a preferred embodiment,
It comprises 0.5 to 2% by weight of platinum.

Hydroisomerization is 10451-17326 k
343 ° C. at a partial pressure of hydrogen of Pa (1500 to 2500 psig)
-(650 ° F-) the conversion to the product should not exceed 30% by weight, based on the feed to the isomerization step, preferably from 10 to 20% by weight, based on the feed to the isomerization step. Can be. The temperature at which the isomerization step is performed is preferably
Do not exceed 427 ° C (800 ° F), preferably 316 to
427 ° C (600-800 ° F).

The hydroisomerization product has a loss during dewaxing of 1
It can be dewaxed to achieve the target pour point, not exceeding 5% by weight. The viscosity index of the product is
Usually, it is 130 to 150.

In this process, the paraffins present in the feedstock are selectively converted into isoparaffins having a high viscosity index but a low pour point, followed by a good degree of dewaxing with good viscosity properties. The final lubricating oil product is obtained. A low acid zeolite hydroisomerization catalyst is used, and the zeolite component is low acidity type zeolite beta. To promote the desired hydroisomerization reaction,
Noble metals, preferably platinum, are used to provide the hydrogenation-dehydrogenation function. This process modifies a waxy feed such as a crude wax having an aromatics content greater than about 15% by weight to provide a high single index yield and a high viscosity index lubricating oil with limited need for product dewaxing. It is very suitable for the method of obtaining.

The advantage of the yield associated with the use of a low acid hydroisomerization catalyst at high hydrogen pressures applied in the present invention is that the application of high hydrogen pressures with high acidity catalysts results in lower isomerization selectivities. It is unpredictable because it is shown.

The present invention can be operated with a wide range of feedstocks derived from mineral oil to produce a range of lubricating oil products having good performance, especially low pour point and high viscosity index. The quality of the product and the yield in obtaining it depend on the quality of the raw material and the ease of processing with the catalyst of the present invention. However, low viscosity index products can be obtained from other feedstocks that have a low initial wax content and are converted to high viscosity index isoparaffins by isomerization catalysts. In particular, when preparing or processing the raw materials under conditions that maximize the viscosity index, it is necessary to remove low quality components at some point,
At the same time, the yield is affected, so that even when a raw material having a low wax content is used, the yield is low.

The feedstock that can be used should have an initial boiling point greater than or equal to the desired lubricating oil initial boiling point. Since the initial boiling point of this lubricating oil is generally about 650 ° F. (about 343 ° C.) or higher, the feedstock is typically 650 ° F. + (About 343 ° C.)
+) It is a fraction. Such feeds that can be used include vacuum gas oils, other high boiling fractions such as distillates from vacuum distillation of atmospheric resids, and residuals from solvent extraction of such distillate fractions. Contains oil.

[0021] The feed may require pre-treatment to be satisfactorily processed in the hydroisomerization step. Usually necessary pre-treatment steps are steps to remove aromatic components and low viscosity index components such as polycyclic naphthenes. Removal of these materials provides a feed to a hydroisomerization process that contains a high amount of waxy paraffins that are later converted to high viscosity index, low pour point isoparaffins. High quality lubricating oil,
That is, for the production of a material having a viscosity index of about 140, the feed to the hydroisomerization step should have a viscosity index of at least 130, but lower quality by using a feedstock having a lower viscosity index. The product can be manufactured.

A preferred pretreatment step for preparing the feed for hydroisomerization is to remove aromatics and other low viscosity index components from the initial feed. Solvent extraction with solvents such as furfural, phenol or N, N-dimethylformamide can be used for this purpose, as well as hydrotreating at high hydrogen pressures particularly useful for aromatic saturation, e.g., 1500 psig (about 10441 kPa) or higher. It is suitable. Hydrotreatment may be preferred over solvent extraction given the losses that occur during the extraction process.

Preferred gas oils and distillate feeds are AST
Raw materials having a high wax content as determined by MD-3235, preferably greater than about 50% by weight. Such feedstocks include, for example, certain South-East Asian and mainland China oils. These feedstocks usually have a high paraffin content as determined by general P / N / A analysis. The properties of a typical feed of this type are shown in Tables 1 and 2 below:

Table 1Minas light oil  Nominal boiling point, ° C (° F) 345-540 (650-1000) API gravity 33.0 Hydrogen, weight% 13.6 sulfur, weight% 0.07 nitrogen, ppmw 320 basic nitrogen, ppmw 160 CCR 0.04 composition , Weight% 60 paraffin 23 naphthene 23 aromatic component 17 bromine number 0.8 100 ° C kinematic viscosity, cSt 4.18 pour point, ° C (° F) 46 (115) 95% TBP, ° C (° F) 510 (950) )

[0025]Table 2  Hydrotreated Minas light oil  Nominal boiling point, ° C (° F) 345-510 (650-950) API gravity 38.2 Hydrogen, wt% 14.65 Sulfur, wt% 0.02 Nitrogen, ppmw 16 Pour point, ° C (° F) 38 (100 ) 100 ° C. kinematic viscosity, cSt 3.324 P / N / A weight% paraffin 66 naphthene 20 aromatic component 14

A preferred raw material for producing the highest viscosity index product is ASTM Test D323
A petroleum wax containing at least 50% of the wax as measured by 5. Among these mineral oil-derived raw materials, wax is a substance having a high pour point, which comprises linear and slightly branched paraffin such as methyl paraffin.

Petroleum waxes, or paraffinic waxes, are usually removed from a waxy purified stream by physical separation, typically by cooling the stream to a temperature at which the wax separates, by solvent dewaxing, such as MEK / toluene dewaxing. Or derived by refining petroleum and liquids by a self-cooling process such as propane dewaxing. These waxes are available at about 650 ° F (about 343 ° C).
Having a high initial boiling point of over 650 ° F. (about 343 ° C.), which is extremely useful for processing into lubricating oils that also require an initial boiling point of at least 650 ° F. Low boiling components should not be excluded as they are removed along with products of similar boiling range produced during processing in a separation step following the characteristic processing step. However, as these components accumulate in the processing equipment, they are preferably eliminated by appropriate selection of the raw material cut point. The end point of the wax raw material varies depending on the characteristics of the stream from which the wax has been removed. According to the distillate (neutral) stream, the wax whose end point does not exceed about 1050 ° F (about 565 ° C) is usually used. Although higher boiling wax feeds, such as petroleum waxes obtained, ie, waxes separated from bright stock, may be used, these waxes typically have an end point of about 1300 ° F. (about 705 ° C.). ).

The preferred raw material has a high wax content, usually at least 50% by weight, more usually at least 60-80% by weight, and contains a balanced amount of an occluded oil consisting of isoparaffins, aromatics and naphthenes. .
The non-wax component content usually does not exceed about 40% by weight of the wax, preferably does not exceed 25-30% by weight. These waxy high paraffinic wax raw materials are usually
Low viscosity due to low aromatic and naphthenic content, but high waxy paraffin content results in melting points and pour points that would be unacceptable as a lubricating oil without further processing.

A preferred type of wax feed is a crude wax, ie, a wax product obtained directly from a solvent dewaxing process, such as a MEK or propane dewaxing process. Crude wax, which is a solid or semi-solid product comprising paraffins with the highest waxiness (mostly n- and monomethyl paraffins), may be used as such, or as raw materials, together with an occluding oil. An initial deoiling step of a general nature can be used to remove the occluded oil (cow foot oil) to form a harder, more paraffinic wax that can be made. Cow foot oil contains the majority of the aromatic components present in the original crude wax and the majority of the heteroatoms along with the aromatic components. That is, a deoiling step is desirable because it removes undesirable aromatic components and heteroatoms that would otherwise lower the viscosity index of the final product through a hydroisomerization step. The oil content of the deoiled wax can be quite low, so that the D-3235 test tends to be unreliable at oil contents less than about 15% by weight and thus the ASTM
Determination of the oil content by the technique of D721 is required for reproduction. However, at oil contents less than about 10% by weight, the advantages of the present zeolite catalyst are about 10-5
It is not as pronounced as in the case of an oil content of 0% by weight, for which reason wax raw materials meeting this requirement are usually used.

The composition of some typical waxes is shown in Table 3 below.
Show. Table 3Arabite Crude Oil Wax Composition  A B C D  Paraffin, wt% 94.2 81.8 70.5 51.4 Mononaphthenes, wt% 2.6 11.0 6.3 16.5 Polynaphthenes, wt% 2.2 3.2 7.9 9.9 Aromatic component, wt% 1.0 4.0 15.3 22.2

A typical crude wax has the composition shown in Table 4 below. This crude wax is obtained by solvent (MEK) dewaxing of 300 SUS (65 cSt) neutral oil obtained from Arabite crude oil.

Table 4Properties of crude wax  API specific gravity 39 hydrogen, wt% 15.14 sulfur, wt% 0.18 nitrogen, ppmw 11 melting point, ° C (° F) 57 (135) 100 ° C kinematic viscosity, cSt 5.168 PNA, wt%: paraffin 70.3 Naphthene 13.6 Aromatic component 16.3

Another crude wax suitably used in the method of the present invention has the properties shown in Table 5 below. This wax was prepared by solvent dewaxing of 450 SUS (100 cS) neutral raffinate.

Table 5Properties of crude wax  Boiling range, ° C (° F) 375-567 (708-1053) API gravity 35.2 Nitrogen, basic, ppmw 23 nitrogen, total, ppmw 28 sulfur, wt% 0.115 hydrogen, wt% 14.04 Pour point , ° C (° F) 50 (120) Kinematic viscosity (100 ° C) 7.025 Kinematic viscosity (300 ° F, 150 ° C) 3.227 Oil (D3235) 35 Molecular weight 539 P / N / A: paraffin-naphthene-aromatic Family component 10

The paraffin component present in the initial wax feed has excellent viscosity index properties, but as a result of its paraffin properties has a relatively high pour point. That is, the purpose of hydroisomerization is to selectively convert these paraffin components to obtain isoparaffins that have good viscosity properties and also a high pour point. This allows the pour point of the final product to be obtained without undue dewaxing following hydroisomerization.

The catalyst used in the hydroisomerization is a catalyst that has a high degree of selectivity in isomerizing linear or nearly linear waxy paraffins to a less waxy isoparaffinic product. This type of catalyst has two performances and comprises a metal component on a large pore porous support having relatively low acidity. The acidity is maintained at a low level to reduce conversion to products boiling outside the lube oil boiling range at this stage of the operation. Generally, an alpha value of 20 or less should be used, with a preferred value of 10
And the best results are obtained when the alpha value is 5 or less.

The alpha value is a rough value indicating the catalytic cracking activity of the catalyst in comparison with a standard catalyst. The alpha test gives the relative rate constant (n-hexane conversion rate per unit time per unit catalyst volume) of the test catalyst relative to a standard catalyst that defines the alpha value as 1 (rate constant = 0.016 / sec). The alpha test is described in U.S. Pat. No. 3,354,078 and the Journal of Catalysis,
4, 527 (1965), 6, 278 (1
966) and 61, 395 (1980). The experimental conditions of the test used to determine the alpha value herein are constant temperature of 538 ° C. and Journal of Catalysis, vol. 61, p. 395.
(1980), including various flow rates.

A preferred hydroisomerization catalyst for the second step is
Zeolite beta is used as a support. This is because the zeolite has a remarkable activity in isomerizing paraffin in the presence of an aromatic component. For example, by synthesizing a silicon-rich zeolite having a silica-alumina ratio of greater than about 50: 1, or more easily by steaming a low silica-alumina ratio zeolite to a desired acidic level, Zeolite beta can be obtained. Another approach is to replace some of the framework aluminum in the zeolite with other trivalent elements, such as boron, which essentially reduce the level of acid activity in the zeolite. Preferred zeolites of this type contain skeletal boron, and usually it is preferred that the zeolites contain at least 0.1% by weight, preferably at least 0.5% by weight, of skeletal boron. In zeolites of this kind, the framework consists mainly of silicon, tetrahedrally coordinated and linked by oxygen bridges. Normal,
A trace amount of trivalent element (alumina in the case of aluminosilicate zeolite beta) is also coordinated to form a part of the skeleton.
Although zeolites also contain metals in the pores of the structure, they do not become part of the framework that makes up the characteristic structure of zeolites. The term "skeleton" boron is used to distinguish substances in the zeolite framework that are identified by contributing to the ion exchange capacity of the zeolite from substances that are present in the pores and do not affect the total ion exchange capacity of the zeolite. Used.

Methods for preparing high silica zeolite containing framework boron are known and are described, for example, in US Pat.
269,813 and 4,672,049. As described therein, the amount of boron contained in the zeolite can be varied by mixing different amounts of borate ions into the zeolite-forming solution, for example, by varying the amount of boric acid relative to the amount of silica and alumina. Can be changed by using.

In the low acid zeolite beta catalyst, the zeolite should contain at least 0.1% by weight of boron. Usually, the maximum amount of boron is about 5% by weight of the zeolite, and in most cases does not exceed 2% by weight of the zeolite. The skeleton usually comprises alumina and the silica: alumina ratio is usually at least 30: 1 when the zeolite is synthesized. A preferred zeolite beta catalyst is to steam an initial boron-containing zeolite containing at least 1% by weight of boron (as B ₂ O ₃ ) to about 1%.
It is produced by obtaining a final alpha value not exceeding 0, preferably not exceeding 5.

The steaming conditions should be adjusted to provide the desired alpha value in the final catalyst, typically from about 427 to about 595 ° C (about 800 to about 1100 °).
An atmosphere of 100% steam is used at the temperature of F). Normal,
Steaming is about 1 hour to obtain the desired acidity reduction.
It is performed for 2 to 48 hours, typically about 24 hours. It has been found that the use of steaming to reduce the acid activity of the zeolite is particularly beneficial and results that are not achieved with zeolites having the same acidity in the as-synthesized state. These results are believed to be due to the presence of trivalent metals that are removed from the framework during the steaming operation to enhance the zeolite's performance by a poorly understood mechanism.

The zeolite is used to form the final catalyst,
Usually, it is complexed with a matrix material, and for this purpose common non-acidic matrix materials such as alumina, silica-alumina and silica are suitable, silica is preferred as the non-acidic binder, but substantially non-matrix composite catalysts Non-acidic aluminas such as alpha boehmite (alpha alumina monohydrate) can also be used if they do not impart a certain degree of acidic activity. Even though alumina is non-acidic, it is preferable to use silica as a binder because alumina tends to react with zeolite under hydrothermal reaction conditions for improving its acidity. Zeolites usually have a zeolite: matrix weight ratio of 80:
Complexed with the matrix as 20-20: 80, typically 80: 20-50: 50. Crush the substances together,
The conjugation can then be carried out by common means, including extruding or pelletizing to the desired final catalyst particles. A preferred method for extruding zeolites with silica as a binder is disclosed in US Pat.
No. 82,815. If the catalyst is to be steamed to achieve the desired low acidity, it is done after combining the catalyst with a binder, as is commonly done.

The isomerization catalyst also contains a metal component to promote the desired hydroisomerization reaction which proceeds through the unsaturated transition species and requires conditioning by the hydro-dehydrogenation component. To maximize the isomerization activity of the catalyst, metals having a strong hydrogenation function are preferred, and therefore other noble metals such as platinum and palladium are preferred. The amount of noble metal hydrogenation component is typically from 0.5 to 5% by weight of the total catalyst, usually from 0.5 to 5%.
2% by weight. Platinum can be incorporated into the catalyst by common techniques including ion exchange with a platinum complex cation such as platinum tetraamine or impregnation with a solution of a soluble platinum compound, for example a platinum tetraamine salt such as platinum tetraamine chloride. The catalyst can be subjected to a final calcination under general conditions to convert the noble metal to an oxide and impart the desired mechanical strength to the catalyst. Prior to use, the catalyst can be presulfurized by established techniques.

The conditions for the hydroisomerization include the conversion of the linear and nearly linear waxy paraffin components in the feedstock to a non-lubricating oil boiling range product (usually 345 ° C- (650 ° F-) material). Is adjusted to achieve the purpose of isomerizing to a relatively low pour point, low waxy, but high viscosity index isoparaffinic material while minimizing isomerization. Due to the low acidity of the catalyst used, the conversion to low-boiling products is usually relatively low, and with a proper choice of severity, the operation of the process may be best for isomerization over cracking. can do. At a typical space velocity of about 1 using a platinum / zeolite beta catalyst having an alpha value of 5 or less, the temperature for hydroisomerization is typically about 315 ° C to 415 ° C.
(About 600 ° F. to about 780 ° F.), and 343 ° C. + (6
A conversion of 50 ° F +) is typically about 1% of the waxy feed.
0-40% by weight, more usually about 12-30% by weight. However, temperatures outside this range, eg, about 26
Temperatures from 0 ° C (about 500 ° F) to about 425 ° C (800 ° F) can be used. However, higher temperatures are usually not preferred because at higher operating temperatures the hydrogenation reaction is less thermodynamically favorable, resulting in a lower isomerization selectivity and a less stable lubricating oil product. The space velocity is typically 0.5-2 LHSV (hr ^-1 ),
In most cases, a space velocity of about 1 LHSV is most preferred.

Hydroisomerization should be at least 1000 psig
(6991 kPa), usually 1000-3000 psig (699
1-20771 kPa), in most cases 1500-250
It is carried out at a partial pressure of hydrogen (reactor inlet) of 0 psig (10451-17326 kPa). The amount of hydrogen circulation is usually about 500 to
5000 SCF / Bbl (about 90 to 900 n.ll ^-1 ). Since the aromatic component present in the first raw material is partially saturated in the presence of the catalyst-supported noble metal hydrogenation component, hydrogen is consumed in the hydroisomerization even if the desired isomerization reaction is hydrogen-balanced. You. For this reason, the amount of hydrogen circulation must be adjusted according to the aromatic content of the feed and the temperature used in the hydroisomerization. This is because higher temperatures lead to more severe decomposition, which in turn increases the production of olefins, some of which fall within the lubricating oil boiling range and which require product stability to be ensured by saturation. is there. At least 1000 SCF / Bbl (about 180
A hydrogen recycle rate of nll ^-1 ) usually compensates for the expected hydrogen consumption and provides enough hydrogen to guarantee a low catalyst aging rate.

The relatively low temperature conditions suitable for isomerization of paraffins are disadvantageous for the cracking reaction, but especially for lubricating oil range saturation of olefins that can be formed by cracking in the presence of a catalyst-supported highly active hydrogenation component. Thermodynamically preferred. For this reason, hydroisomerization is also effective in hydrofinishing the product, and therefore, product stability, a property often lacking in normal hydrocracking lubricating oil products, especially stability to ultraviolet radiation. Is improved. Thus, the isomerized product need only be subjected to a final dewaxing step to achieve the desired pour point, and optimal processing in two functionally separated process steps results in aromatic and lube range olefins. No further finishing step is usually required, since the unsaturation content of both is lower. The product can be subjected to a final fractionation to remove low boiling materials, followed by a final dewaxing step to achieve the target pour point of the product.

Although a final dewaxing step is usually required to achieve the desired product pour point, a relatively small degree of dewaxing is a notable feature of the process of the present invention. . Typically, losses during the final dewaxing step do not exceed 15-20% by weight of the dewaxed feedstock and may be lower. In this regard, either catalytic dewaxing or solvent dewaxing can be used, and if solvent dewaxing is used, the removed wax can be recycled to hydroisomerization and subjected to a second isomerization step. . The requirements for dewaxing equipment for the product are relatively low, and in this regard, the present invention is significantly superior to processes that require strong dewaxing using only amorphous catalysts. The high isomerization selectivity of the zeolite catalyst allows for the achievement of high single-stream conversions, typically about 80% conversion for 50% of amorphous catalyst processes, so that the output of the unit Is greatly improved.

The process product is a substance having a high viscosity index and a low pour point and is obtained in excellent yield. In addition to having excellent viscosity properties, this material is also very stable oxidatively and thermally as well as to UV light. A product yield of at least 50% by weight based on the initial wax feed;
Usually at least 60% by weight (approximately 80 and 9 respectively)
(Corresponding to 0% wax conversion), a viscosity index in the range of 125 to 150 is typically obtained if a value of at least 140, typically 143-147, can be achieved.

[0049]

The following examples are provided to illustrate various features of the method of the present invention. Examples 1 and 2 illustrate the preparation of a low acid platinum / zeolite beta catalyst containing skeletal boron.

[0050]Example 1  The following mixture was stirred at 140 ° C. (285 ° F.) for 13 days
Boron-containing zeolite beta by intercrystallization
The catalyst was prepared: boric acid, g 57.6 50% sodium hydroxide, ml 66.0 TEABr, ml 384 seeds, g 37.0 silica, g 332 water, g 1020 Notes: 1 TEABr = tetraethylammonium bromide
50% aqueous solution of silica 2 silica = Ultrasil
l: registered trademark)

The calcined product showed the following analysis and was confirmed by X-ray diffraction to have the structure of zeolite beta: SiO ₂ 76.2 Al ₂ O ₃ 0.3 boron 1.08 sodium, ppm 1070 nitrogen 1.65 Ash 81.6

[0052]Example 2  The as-synthesized boron-containing zeolite base of Example 1
And the zeolite: silica weight ratio is 65:35.
And extruded with silica, dried, 480 ° C in nitrogen
(900 ° F) for 3 hours followed by 540 ° C in air
(1000 ° F.) for 3 hours. The resulting extrudate is placed in a chamber
Exchange with 1N ammonium nitrate solution for 1 hour at room temperature,
Thereafter, the exchange catalyst was placed in air at 540 ° C. (1000 ° F.) for 3 hours.
Firing for 550 ° C (1025 ° in 100% steam)
F) for 24 hours. The steamed extrudate is
Boron (B_TwoO_Three0.48% by weight, sodium 36
5 ppm and Al_TwoO_ThreeIt is found that it contains 1920 ppm
won. 1N platinum tetraamine
Replaced with a chloride solution for 4 hours at room temperature
Performed at 350 ° C. (660 ° F.) for 3 hours. Finished touch
The medium contains 0.87% by weight of platinum and has an alpha value of 4.
Was.

[0053]Example 3  SiO_Two/ Al_TwoO_ThreeAluminosilicate with volume ratio of 40
Extrude zeolite beta sample with alumina
And 65% zeolite / 35% Al_TwoO_Three(% By weight) cylindrical
Extrudates were produced. This material is dried, calcined and steamed.
The alpha value was reduced to 55 upon mining. Pt (N
H_Three)_FourCl_TwoPlatinum is incorporated by ion exchange using
The final platinum loading was 0.6% by weight.

[0054]Example 4  This example demonstrates that low acid zeolite beta hydroisomer
Explains the wax hydroisomerization process using an hydration catalyst
You. This process uses low pressure (400 psig / 2860 kPa)
And high pressure (1750 psig / 12170 kPa)
Operated below.

The low-acid silica-bound zeolite beta catalyst prepared by the method described in Example 2 above was charged to a reactor as 30/60 mesh particles (Tyler) particles, and 2% H ₂ S / 98% The reactor temperature was raised to 400 ° C. (7 psi) using H ₂ at a pressure of 50 psig (445 kPa absolute).
Sulfurized by raising to 50 ° F). A crude wax having the properties shown in Table 6 below was used as a raw material.

[0056]

[0057]

The crude wax feed was charged directly to the catalyst as a co-current downflow with hydrogen under the following conditions: LHSV, hr ^-1 0.5 hydrogen flow, SCF / Bbl (nll ^-1 ) 2500 (4)
55) Total pressure, psig 400 and 1750 (kPa absolute) (2857 and 12
159)

As described below, the temperature was increased to about 370-4 to obtain different wax conversion levels of 10-30%.
It was varied in the range of 15 ° C (700-780 ° F). The results are shown in Table 8 below and FIGS. 1 and 2.

[0060]Example 5  Aluminosilicate zeolite beta catalyst of Example 3
Was charged into a reactor and presulfurized as described in Example 4 above.
And hydroisomerizes the same crude wax raw material under the following conditions:
Used to:

LHSV, hr ^-1
1.0 Hydrogen flow rate, SCF / Bbl (nll ^-1 ) 2000 (3
56) Total pressure, psig 400 and 2000 (kPa absolute) (2857 and 13
881)

As described below, to obtain different wax conversion levels of 5-45%, the temperature was increased to about 345-40.
The temperature was varied in the range of 0 ° C (650-750 ° F). The results are shown in Table 8 below and FIGS. 1 and 2.

[0063]Example 6  This example shows that in a single step high pressure hydroprocessing operation
The use of an amorphous catalyst will be described. Has the characteristics shown in Table 7
NiW / Al_TwoO_ThreeA hydrogen cracking catalyst was used.

[0064]

The catalyst was charged into a downflow reactor and sulfided as in Example 4 above. The catalyst was fluorinated using o-fluorotoluene (25 ppm) as a dopant in the raw materials. Hydrogen is fed to the reactor as a co-current downflow under the following conditions with the same crude wax as described in Example 4, and again under the following reaction conditions a conversion of about 5% to 75%
The temperature was varied from about 370 ° C. to 415 ° C. (700 ° F. to 780 ° F.).

LHSV, hr ^-1
1.0 Hydrogen flow rate, SCF / Bbl (nll ^-1 ) 7500 (1
335) Total pressure, psig (kPa absolute pressure) 2000 (1
3881)

The lubricating oil yield and the properties of the obtained lubricating oil are shown in Table 8 below and FIGS. 1 and 2.

Table 8Lubricating oil yields and properties  Example number4 5 6  Catalyst4αPt / beta 55αPt / beta NiW / alumina  Pressure, psig 400 1750 400 1750 2000 kPa 2857 12159 2857 12159 13881 Lubricant yield, wt% 55-58 61 51 41 46 100 ° F kinematic viscosity, cS 5.8 6.0 5.8 7.0 5.0 Lubricant viscosity index 135-137 133-134 127 121 142

FIG. 1 and FIG. 2 show that 343 ° C .- (6
The yield and viscosity index data are compared as a function of crude wax conversion, defined as the new amount of feed converted to the 50 ° F.-) category. The yield is 650 remaining after solvent dewaxing to achieve a -18 ° C (0 ° F) pour point product.
° F + determined by the amount of material.

The results summarized in Table 8 and shown in FIGS. 1 and 2 show that the Pt / zeolite beta was obtained without the yield and viscosity index degradation that would occur with comparable but more acidic catalysts. It has been shown that crude wax can be processed under high pressure using a low acid catalyst such as
These results indicate that the low acid Pt / zeolite beta catalyst of Example 2 (4α) provided the highest yield for the processing of crude wax feed as shown in Example 4, and that the 4αPt / zeolite beta catalyst had Amorphous Ni used in Embodiment 6
This shows that it produces 15% more lubricating oil than the W / Al ₂ O ₃ catalyst and 10-20% more lubricating oil than the more acidic 55αPt / zeolite beta catalyst used in Example 5. ing. By increasing the operating pressure of the hydroisomerization, the yield greatly decreases in the case of the highly acidic Pt / zeolite beta catalyst used in Example 5, but in the case of the low acidic Pt / zeolite beta catalyst used in Example 4, The yield increases. With a low acid Pt / zeolite beta catalyst, the viscosity index of the product is not affected by pressure as strength as with a high acid Pt / zeolite beta catalyst.

[Brief description of the drawings]

FIG. 1 is a graph showing yield as a function of crude wax conversion, defined as the new amount of feed converted to a 343 ° C .- (650 ° F.) segment.

FIG. 2 is a graph showing the viscosity index as a function of crude wax conversion as in FIG.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Dominique Nicholas Maison No. 10, North Monroe Avenue, Wenona, New Jersey, 08090, United States of America (56) Reference JP-A-62-112691 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) C10G 45/64 C10G 65/12 C10G 67/04

Claims (16)

(57) [Claims] 1. Paraffin content of at least 40% by weight
A high viscosity index lubricating oil having a viscosity index of at least 125 from a petroleum wax feed comprising a noble metal hydrogenation component on a porous zeolite support in the presence of hydrogen at a hydrogen partial pressure of at least 6991 kPa (1000 psig). Wherein the waxy paraffins present in the feed are isomerized to less waxy isoparaffins in the presence of a low acid zeolite isomerization catalyst having an alpha value not exceeding 20. 2. The raw material has a wax content of at least 60.
A process according to claim 1 comprising petroleum wax having a weight percent and an aromatics content of 5 to 20 weight percent. 3. A petroleum wax having an aromatic content of 8 to 12.
3. A process according to claim 1, comprising by weight of crude wax. 4. The isomerization catalyst according to claim 1, comprising a zeolite beta isomerization catalyst having an alpha value not exceeding 10.
A method according to any one of claims 1 to 3. 5. The process according to claim 4, wherein the alpha value of the catalyst does not exceed 5. 6. The process according to claim 1, wherein the isomerization catalyst comprises a boron-containing zeolite beta isomerization catalyst in which boron is present as a framework component of zeolite beta. 7. The method according to claim 1, wherein the zeolite is complexed with a matrix material. 8. The process according to claim 1, wherein the isomerization catalyst contains 0.5 to 2% by weight of platinum. 9. The hydroisomerization is carried out at 10451 to 17326 k.
9. The process according to claim 1, wherein the process is carried out at a hydrogen partial pressure of Pa (1500-2500 psig). 10. The isomerization step is carried out at 343 ° C .- (650 °
F-) Conversion to product is 3 based on feed to isomerization step
The method according to any one of claims 1 to 9, wherein the reaction is performed so as not to exceed 0% by weight. 11. 343 ° C .- (650 ° C.) during the isomerization step.
The process according to claim 10, wherein the F-) conversion is from 10 to 20% by weight, based on the feed to the isomerization step. 12. The isomerization step is performed at 427 ° C. (800 ° F.).
The method according to any of claims 1 to 11, which is carried out at a temperature not exceeding. 13. The isomerization step is carried out at 316 to 427 ° C. (60 ° C.).
13. The method according to claim 12, which is carried out at a temperature of from 0 to 800 ° F). 14. The process according to claim 1, wherein the hydroisomerization product is dewaxed to achieve a target pour point with a loss during dewaxing not exceeding 15% by weight. the method of. 15. The process according to claim 1, wherein the viscosity index of the product is from 130 to 150. 16. The method according to claim 1, wherein the raw material comprises a deoiled wax, a crude wax or a solvent refined raffinate.