JP3651951B2 - Method for producing base oil for lubrication - Google Patents

Description

【００１９】
表中の記号Ｉ／Ｉ₀ ＊１００は相対強度を表し、Ｉ₀ は最強線の強度であり、ｄは記録された線に対応する格子面間隔（単位オングストローム）である。Ｘ線粉末回折パターンは、Ｋ−アルファ／二重線銅照射を用いて、標準的方法で測定できる。
シリコ−アルミノホスフェートは更に、表面のＰ₂ Ｏ₅ 対アルミナのモル比が０．８０以下であるとい特徴も有し、シリコ−アルミノホスフェート本体（ｂｕｌｋ）のＰ₂ Ｏ₅ 対アルミナのモル比は０．９６以上であり、表面のシリカ対アルミナのモル比はシリコ−アルミノホスフェート本体のそれより大きい。このシリコ−アルミノホスフェートは当業界ではＳＭ−３として知られている。ＳＭ−３の製造は国際特許出願ＷＯ ９１／１３１３２号に開示されている。
【００２０】
本発明の更に別の具体例では、異性化触媒は、国際特許出願ＷＯ ９３／０２１６１号に記載のように、非層状の無機多孔性結晶質相物質を含む。
水素異性化触媒は典型的には、水素化／脱水素化活性を有する触媒活性金属、例えばＶＩｂ族及びＶＩＩＩ族の金属を含む。水素異性化触媒は、ＶＩＩＩ族金属、特にＶＩＩＩ族貴金属、例えばプラチナ及び／又はパラジウムを含むのが好ましい。前述のような分子篩を含む触媒担体に金属を含ませる手段は当業者によく知られており、既に説明した。前記貴金属の量は典型的には、触媒全体の０．５〜５重量％、好ましくは０．５〜２重量％の範囲にする。
【００２１】
本発明の方法の水素異性化段階では、蝋状ラフィネートを、前述の触媒の存在下で、高温高圧で水素と接触させる。典型的には、潤滑用ベース油を得るのに必要な温度は１７５〜３８０℃、好ましくは２００〜３５０℃である。通常加える圧力は、１０〜２５０バール、より好ましくは２５〜２５０バールである。蝋状ラフィネートは、０．１〜２０ｋｇ／ｌ／ｈｒ、好ましくは０．１〜５ｋｇ／ｌ／ｈｒの重量毎時空間速度で供給し得る。
最終的潤滑用ベース油は、−１５℃未満、より好ましくは−２０℃未満の流動点を有し、１３５を超えるＶＩ、好ましくは１４０を超えるＶＩを有するのが好ましい。水素化し水素化変換し水素異性化した潤滑用ベース油は、更に流動点降下処理する必要がないことが好ましい。しかしながら、蝋状ラフィネートを中間流動点まで異性化し、異性化した蝋状ラフィネートを最終流動点まで溶剤脱蝋することが望ましいこともあり得る。[0001]
[Industrial application fields]
The present invention relates to a method for producing a lubricating base oil, and more particularly to a method for producing a very high viscosity index lubricating base oil from a mixture of carbon monoxide and hydrogen.
The term “extremely high viscosity index” means a viscosity index (VI) of greater than 135 as measured by ASTM-D-2270.
[0002]
[Prior art]
A process for producing hydrocarbons by contacting a mixture of carbon monoxide and hydrogen with a suitable synthesis catalyst at elevated temperature and pressure is known in the art as Fischer-Tropsch synthesis. It is known in the art to apply the Fischer-Tropsch synthesis process to the production of a series of predominantly aliphatic hydrocarbons with a wide range of molecular weights.
In order to increase the yield of useful hydrocarbon products by the Fischer-Tropsch synthesis method, various processing methods have been proposed to improve the Fischer-Tropsch product. For example, US Pat. No. 4,125,556 describes a Fischer-Tropsch synthesis high olefin effluent from one or more distillations, polymerizations, alkylations, hydrotreats, cracking-decarboxylations, isomerizations. And a method of processing by hydroforming. This process yields products mainly in the gasoline, kerosene and light oil range.
From the various treatments described above that can be applied to improve the products of the Fischer-Tropsch synthesis, many methods have been proposed that rely on the application of hydroprocessing in an improved operation. For example, US Pat. No. 4,478,955 discloses a process comprising contacting the effluent of a Fischer-Tropsch synthesis process with hydrogen in the presence of a suitable hydrogenation catalyst. This US patent specification describes that the Fischer-Tropsch synthesis effluent mainly contains olefins and carboxylic acids. Under the action of this hydrotreatment, useful fuel components including alkanes, alcohols and esters are produced.
In another process disclosed in U.S. Pat. Nos. 4,059,648 and 4,080,397, the product of the Fischer-Tropsch synthesis is improved by first subjecting it to hydroprocessing and fractionation. After fractionation, a selected fraction of the fractionated product is subjected to a selective hydrocracking process. The process consists of contacting the cut with a special zeolite catalyst that can convert the aliphatic hydrocarbons present in the cut to aromatic hydrocarbons. The resulting aromatic-rich product is stated to be useful as gasoline and light and heavy fuel oils.
There has since been increased interest in applying Fischer-Tropsch synthesis to the production of substantially paraffinic hydrocarbons suitable for use as fuel. Although it is possible to use the Fischer-Tropsch synthesis method directly to produce paraffinic hydrocarbons having boiling points in the boiling range of the fuel fraction, the Fischer-Tropsch synthesis method is used in the boiling range of middle distillates. For the production of high molecular weight paraffinic hydrocarbons having boiling points above the upper limit of i.e. Fischer-Tropsch wax having a boiling point above 370 ° C., and the resulting product is subjected to a selective hydrocracking process to produce the desired It has proved advantageous to obtain a hydrocarbon fuel.
For example, British Patent Specification No. 2 077 289 contacts a mixture of carbon monoxide and hydrogen with a catalyst that is active in a Fischer-Tropsch synthesis, and then the resulting paraffinic hydrocarbon in the presence of hydrogen. Discloses a method for obtaining middle distillate by decomposition. European patent specification 0 147 873 also discloses a similar operating method.
European Patent Application 0 583 836 discloses a process for producing hydrocarbon fuels from carbon monoxide and hydrogen.
Of particular interest, however, is the use of Fischer-Tropsch synthesis to produce hydrocarbons suitable for use as lubricating base oils or lubricating base oil precursors, such as Fischer-Tropsch wax.
Methods for producing very high viscosity index lubricating base oils from Fischer-Tropsch wax feeds are known to those skilled in the art. U.S. Pat. No. 4,594,172 describes Fischer-Tropsch wax C_Ten~ C₁₉Treat the fraction with organic peroxide to obtain C₂₀ ⁺A method for producing an extremely high viscosity index lubricating base oil by obtaining an oligomerized fraction and hydroisomerizing the fraction in the presence of a platinum-containing silica-alumina catalyst is disclosed.
European patent application 0 515 256 discloses a process for hydroisomerizing Fischer-Tropsch wax (hydroconversion) using a catalyst comprising zeolite Y. Solvent dewaxing a fraction having a boiling point above 380 ° C. provides a lubricating base oil having a VI of 130 or higher and a pour point of −12 ° C. or higher. As outlined in this European patent application, unsaturated hydrocarbons and oxygenates can be removed from Fischer-Tropsch wax by hydrotreating prior to hydroisomerization.
European Patent Application 0 321 303 discloses a process for producing middle distillate products from Fischer-Tropsch wax by a hydroisomerization (hydroconversion) process. At least a portion of the lower fraction from the hydroisomerization zone is (a) further processed in the second hydroisomerization zone, or (b) produces a lube oil fraction having a boiling range of 343.3 ° C to 510 ° C. For separation and / or dewaxing. If desired, oxygenates are removed from the Fischer-Tropsch by distillation. The hydroisomerization catalyst used in the first hydroisomerization (hydroconversion) process is platinum on fluorided alumina which is particularly effective (selective) in converting paraffinic Fischer-Tropsch wax to middle distillate. It is a catalyst. In particular, this catalyst has been reported to be more effective than a catalyst comprising zeolite, especially zeolite beta, as described in Example 3 of this European patent application.
In contrast, in Example 3 of said European Patent Application No. 0 515 256, zeolite Y catalyst is as effective as platinum catalyst on silica-alumina in the production of middle distillate from Fischer-Tropsch wax. Although it may be (selective), it is described that the zeolite Y catalyst is much more active. To convert about 40% by weight Fischer-Tropsch wax to a product with a boiling point below 400 ° C, zeolite Y catalyst requires a reactor temperature of 260 ° C, whereas platinum catalyst on silica-alumina is 340 ° C. This is because the reactor temperature is required.
Hydroisomerization (or hydroconversion) processes include both hydrocracking of paraffinic hydrocarbons and isomerization of linear paraffinic hydrocarbons to branched paraffinic hydrocarbons. If it is desired to produce a base oil for lubrication, it is advantageous to minimize hydrocracking activity and maximize hydroisomerization activity. However, some hydrocracking activity is still required to break down the heaviest wax molecules into lower boiling products. The disadvantage of high activity catalysts, such as zeolitic catalysts such as zeolite Y, is that the hydrocracking activity is usually too high and the hydroisomerization activity is too low. As described below, other molecular sieve catalysts are also known, such as silicoaluminophosphates, and other zeolite catalysts that have reduced activity (expressed in acidity) to an alpha-value of less than 20 or less than 10 or 5. Yes. However, these catalysts usually do not have sufficient hydrocracking activity.
For example, European Patent Application 0 464 547 discloses a method for producing high viscosity index lubricants from slack wax by a two-step process. In the first step, the slack wax is hydrocracked under mild conditions using an amorphous catalyst, in particular a catalyst consisting of Ni or W on a fluorinated alumina support, and in the second step, preferably less than 5 Hydroisomerization is carried out using a low acidity zeolite beta catalyst having an alpha value of
The alpha value indicates the approximate magnitude of the catalytic cracking activity of the catalyst compared to the standard catalyst. In the alpha test, an alpha value of 1 (rate constant = 0.016 sec)^-1The relative rate constant (normal hexane conversion rate per catalyst amount per unit time) of the test catalyst compared to the standard catalyst is obtained. Alpha testing is described in U.S. Pat. Catalysis, 4,527 (1965); 6,278 (1966); and 61,395 (1980), discussed in European Patent Application No. 0 464 547. The alpha value is measured on a catalyst support that does not contain a catalytically active metal.
[0003]
As used herein, the term hydroconversion process refers to a process that causes a hydrocracking reaction and a hydroisomerization reaction to be performed in the presence of a catalyst comprising a refractory oxide support.
As used herein, the term hydroisomerization process causes a hydroisomerization reaction and a hydrocracking reaction, but is performed after the hydroconversion, usually when the hydrocracking is a hydroconversion process. It means a process that does not occur as much.
[0004]
A disadvantage of hydroconversion catalysts containing refractory oxide supports is that high operating temperatures are required, especially when the catalyst is used over a long period of time, for example 2 years or more. In order to compensate for the deactivation of the catalyst, the reaction temperature is usually increased. Above 350 ° C, and especially above 400 ° C, at least a portion of the Fischer-Tropsch wax is converted to undesirable aromatics. Thus, hydroconversion at an operating temperature well below 400 ° C., preferably below 350 ° C., using a catalyst comprising a refractory oxide support and a catalytically active metal having hydrogenation / dehydrogenation activity. The discovery of a way to implement the process was awaited.
Surprisingly, Fischer-Tropsch wax (hydrocarbon wax) is first converted to hydrogen in the presence of a hydrogenation catalyst under conditions such that hydroisomerization or hydrocracking of the hydrocarbon wax does not occur substantially. In contact, it has been found that the hydroconversion process can be carried out at reaction temperatures of less than 400 ° C., even less than 350 ° C., even after the hydroconversion catalyst has been used for a long period of time, for example 2 years or longer. Compared with the method in which Fischer-Tropsch is contacted with the hydroconversion catalyst without first performing the hydrogenation step, the reaction temperature can be lowered by 5 ° C. or more, preferably 10 ° C. or more.
Furthermore, it has been found that the hydroconversion catalyst has a much slower deactivation rate in the method including the step of performing hydrogenation first. Accordingly, the rate of increase of the reaction temperature required to compensate for the loss of catalytic activity can be greatly reduced.
Also, most surprisingly, the process comprising a hydrogenation step and a hydroconversion step is a useful hydrocarbon having a boiling point in the lubricating base oil range compared to prior art methods comprising only a hydroconversion step. It was found that it shows a great selectivity for.
[0005]
Therefore, the present invention provides a method for producing a lubricating base oil, which includes an operation of subjecting the waxy raffinate to a pour point depressing treatment and recovering the lubricating base oil therefrom. The waxy raffinate is formed by the hydrocarbon product in the presence of a hydroconversion catalyst comprising a catalytically active metal having hydrogenation / dehydrogenation activity supported on a refractory oxide support. Produced by contacting with hydrogen under conditions such that hydrocracking and hydroisomerization occur to obtain a waxy raffinate, wherein the hydrocarbon product comprises (a) carbon monoxide and hydrogen The mixture is contacted with a hydrocarbon synthesis catalyst at high temperature and pressure to produce a substantially paraffinic hydrocarbon wax, and (b) the resulting hydrocarbon wax is added to the hydrocarbon wax in the presence of a hydrogenation catalyst. It is produced by contacting with hydrogen under conditions such that hydroisomerization or hydrocracking does not occur substantially to obtain a hydrocarbon product.
[0006]
As used herein, the conditions under which the hydrocracking or hydroisomerization of step (b) of the method of the present invention does not substantially occur are those of the feedstock with a boiling point of over 370 ° C. in step (b). The conversion from a fraction to a fraction having a boiling point of less than 370 ° C. is defined as a condition such that it is less than 10% expressed in weight%.
The conditions under which hydrocracking and hydroisomerization of hydrocarbon products occur in the hydroconversion step are defined as the conditions under which the conversion defined above is 15% or more. .
As used herein for hydrocarbon waxes, the term “substantially paraffinic” means a hydrocarbon mixture comprising 70% by weight or more, preferably 80% by weight or more of paraffin. The hydrocarbon wax produced by the process of the present invention usually contains 90% by weight or more of paraffin, more typically 95% by weight or more of paraffin.
[0007]
In step (a) of the process of the present invention, a feedstock comprising a mixture of carbon monoxide and hydrogen is contacted at high temperature and pressure with a catalyst that is active in the synthesis of paraffinic hydrocarbons. Suitable methods for producing a mixture of carbon monoxide and hydrogen are well known to those skilled in the art, for example, partial oxidation of methane, typically in the form of natural gas, and steam reforming of methane. There is a method such as (team reforming). The relative amounts of carbon monoxide and hydrogen in the feed can be varied within a wide range and can be selected according to the exact catalyst and operating conditions used. Typically, the feedstock contacted with the catalyst comprises carbon monoxide and hydrogen in a hydrogen / carbon monoxide molar ratio of less than 2.5, preferably less than 1.75. More preferably, the hydrogen / carbon monoxide ratio ranges from 0.4 to 1.5, in particular from 0.9 to 1.3. Unconverted carbon monoxide and / or hydrogen can be separated from the synthesis product and recycled to the inlet of the synthesis reactor.
Suitable catalysts for use in the synthesis of paraffinic hydrocarbons are known to those skilled in the art. Typically, the catalyst comprises a Group VIII metal of the Periodic Table of Elements as a catalytically active component. Specific catalytically active metals of Group VIII include ruthenium, iron, cobalt and nickel. In the method of the present invention, a catalyst containing cobalt as a catalytically active metal is preferred.
The catalytically active metal is preferably supported on a porous carrier. The porous support may be selected from any suitable refractory metal oxide or silicate or mixture thereof. Specific examples of preferred supports include silica, alumina, titania, zirconia and mixtures thereof. Particularly preferred are supports made of silica and / or alumina.
The catalytically active metal can be combined with the support by any method known to those skilled in the art, such as co-mulling, impregnation or precipitation. Impregnation is a particularly preferred method and consists of contacting the support and the catalytically active metal compound in the presence of a liquid, most advantageously in the presence of a liquid having the form of a solution of said metal compound. The active metal compound may be inorganic or organic, but preferred are inorganic compounds, especially nitrates. The liquid used can also be organic or inorganic. The most advantageous liquid is water.
The amount of catalytically active metal present on the support is typically 1-100 parts by weight, preferably 10-50 parts by weight, per 100 parts by weight of the support material.
The catalytically active metal can be present in the catalyst together with one or more metal promoters or cocatalysts. The promoter may have a metal or metal oxide form, depending on the specific promoter. Suitable metal oxide promoters include Group IIA, IIIB, IVB, VB or VIB group metal oxides, lanthanide and / or actinide oxides of the periodic table. The catalyst preferably comprises an element of group IVB of the periodic table, in particular an oxide of titanium or zirconium. Particularly preferred are catalysts containing zircon. Instead of or in addition to the metal oxide promoter, the catalyst may comprise a metal promoter selected from groups VIIB and / or VIII of the periodic table. Preferred metal promoters include platinum and palladium. The most suitable catalysts contain cobalt as the catalytically active metal and zircon as the promoter. The promoter may be included in the catalyst using any of the methods described above for the catalytically active component.
The amount of promoter when the promoter is included in the catalyst is typically 1-60 parts by weight, preferably 2-40 parts by weight per 100 parts by weight of the support material.
Hydrocarbon synthesis is carried out under high temperature and high pressure conditions. Typically, the synthesis is carried out at a temperature in the range of 125-300 ° C, preferably 175-250 ° C. The reaction pressure is typically 5 to 100 bar, preferably 12 to 50 bar. The synthesis can be carried out in various types of reactors and reaction regimes, such as fixed bed systems, slurry phase systems or ebullating bed systems.
[0008]
The hydrocarbon wax of synthesis step (a) is subjected to hydroprocessing in step (b) of the process of the present invention. The entire synthesis stage effluent may be introduced directly into the hydrogenation step. Preferably, however, the unconverted carbon monoxide and hydrogen and the water produced during the synthesis are separated from the hydrocarbon wax in the synthesis stage. If desired, low molecular weight products in the synthesis stage, especially C_Four-Fractions such as methane, ethane and propane can also be removed before the hydrotreatment. Separation can be advantageously performed using distillation methods well known to those skilled in the art. Alternatively, the hydrocarbon wax is separated into a low boiling fraction having a boiling point of, for example, less than 330 ° C. or less than 370 ° C., and at least one high boiling fraction having a boiling point of greater than 330 ° C. or greater than 370 ° C. High boiling fractions may be treated by the method of the present invention. Separation may be performed using vacuum distillation or short path distillation, such as vacuum film distillation (using a wiped film evaporator).
In the hydrogenation stage, step (b), the hydrocarbon product is contacted with hydrogen in the presence of a hydrogenation catalyst. Suitable catalysts for use at this stage are known to those skilled in the art. Typically, the catalyst is selected from one or more metals selected from groups VIB and VIII of the Periodic Table of Elements, in particular molybdenum, tungsten, cobalt, nickel, ruthenium, iridium, osmium, platinum and palladium. One or more metals are included as catalytically active components. Preferably, the catalyst contains one or more metals selected from nickel, platinum and palladium as catalytically active components.
A particularly suitable catalyst contains nickel as the catalytically active component.
Catalysts for use in the hydrogenation stage typically include a refractory metal oxide or silicate as a support. Suitable carrier materials include silica, alumina, silica-alumina, zirconia, titania and mixtures thereof. Preferred support materials for inclusion in the catalyst used in the process of the present invention are silica, alumina, silica-alumina and diatomaceous earth (kieselguhr).
The catalyst may contain 0.05 to 80 parts by weight, preferably 0.1 to 70 parts by weight, of the catalytically active component per 100 parts by weight of the support material. The amount of catalytically active metal present in the catalyst varies depending on the specific metal. One particularly suitable catalyst for use in the hydrogenation stage comprises nickel in an amount of 30 to 70 parts by weight per 100 parts by weight of support material. Another particularly suitable catalyst comprises platinum in an amount of 0.05 to 2.0 parts by weight per 100 parts by weight of support material.
Catalysts suitable for use in the hydrogenation stage of the process of the present invention are commercially available or can be prepared by methods known to those skilled in the art, such as those described above for hydrocarbon synthesis catalysts.
In the hydrogenation stage, the hydrocarbon wax is contacted with hydrogen at high temperature and pressure. The operating temperature is typically 100-300 ° C, more preferably 150-275 ° C, especially 175-250 ° C. Typically, the operating pressure is 5 to 150 bar, preferably 10 to 50 bar. Hydrogen can be fed to the hydrogenation stage at a gas hourly space velocity in the range of 100 to 10000 Nl / l / hr, more preferably in the range of 250 to 5000 Nl / l / hr. The hydrocarbon wax to be treated is fed to the hydrogenation stage at a weight hourly space velocity typically ranging from 0.1 to 5 kg / l / hr, more preferably from 0.25 to 2.5 kg / l / hr. The ratio of hydrogen to hydrocarbon wax can be 100-5000 Nl / kg, preferably 250-3000 Nl / kg.
The hydrogenation stage is conducted under conditions such that feedstock isomerization or hydrocracking does not occur substantially. The exact operating conditions required to achieve the desired degree of hydrogenation without the occurrence of substantial hydrocracking or hydroisomerization is the composition of the hydrocarbon wax fed to the hydrogenation stage. Depending on the specific catalyst used. As described above, the degree of conversion of the feed hydrocarbons can be determined as a measure of the stringency of the conditions in the hydrogenation stage and thus the degree of hydrocracking and isomerization. In this case, the conversion expressed in% is defined as the weight percent of the feed fraction having a boiling point above 370 ° C. that is converted during the hydrogenation to a fraction having a boiling point below 370 ° C. The conversion rate of the hydrogenation stage is less than 10%, preferably less than 8%, more preferably less than 5%.
[0009]
In the process of the present invention, the hydrocarbon product exiting the hydrogenation stage consists essentially of high molecular weight paraffinic hydrocarbons having a boiling range above the boiling range of the lubricating base oil. The base oil for lubrication typically has a 5 wt% boiling point of 330 ° C or higher, preferably 370 ° C or higher. The boiling range of the lubricating base oil can be up to 650 ° C, preferably up to 600 ° C. These boiling points and boiling ranges are boiling points (ranges) at atmospheric pressure. At least a portion of the hydrocarbon product is subjected to a hydroconversion step of the process of the present invention to produce a waxy raffinate. If desired, the entire hydrogenation stage effluent can be fed directly to the hydroconversion stage. However, preferably, prior to the hydroconversion stage, low molecular weight hydrocarbons, especially C_Four-Separating the fraction from the high molecular weight hydrocarbons. The separation may be advantageously performed by distillation techniques that are well known to those skilled in the art. The remaining C of the hydrocarbon product_Five+ At least a portion of the cut is used as feed for the subsequent hydroconversion stage.
[0010]
In the hydroconversion stage, a waxy raffinate is produced from the product by subjecting the hydrocarbon product of the hydrogenation stage to hydrocracking and hydroisomerization using hydrogen in the presence of a suitable catalyst. Typically, the catalyst is selected from one or more metals selected from groups VIB and VIII of the Periodic Table of Elements, in particular molybdenum, tungsten, cobalt, nickel, ruthenium, iridium, osmium, platinum and palladium. One or more metals are included as catalytically active components. Preferably, the catalyst contains one or more metals selected from nickel, platinum and palladium as catalytically active components. Catalysts containing platinum as the catalytically active component have been found to be particularly suitable for use in the hydroconversion stage.
Catalysts for use in the hydroconversion stage typically include a refractory metal oxide as a support. Suitable carrier materials include silica, alumina, silica-alumina, zirconia, titania and mixtures thereof. Preferred support materials for inclusion in the catalyst used in the process of the present invention are silica, alumina and silica-alumina. A particularly preferred catalyst comprises platinum supported on a silica-alumina support. If desired, the acidity of the catalyst support can be increased by providing the support with a halogen moiety, particularly a fluorine or phosphorus moiety. This may be particularly preferred when the catalyst support itself is not acidic, for example when the catalyst support contains alumina or silica.
The catalyst may contain a catalytically active component in an amount of 0.05 to 80 parts by weight, preferably 0.1 to 70 parts by weight, per 100 parts by weight of the support material. The amount of catalytically active metal present in the catalyst varies depending on the specific metal. Particularly preferred catalysts for use in the hydroconversion stage comprise platinum in an amount of 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight per 100 parts by weight of support material.
Catalysts suitable for use in the hydroconversion stage of the process of the present invention are either commercially available or can be prepared by methods well known to those skilled in the art, such as those described above for the preparation of hydrocarbon synthesis catalysts.
In the hydroconversion stage of the process of the present invention, the hydrocarbon product of the hydrogenation stage is contacted with hydrogen in the presence of a catalyst at high temperature and pressure. Typically, the temperature required to obtain a waxy raffinate is in the range of 175-380 ° C, preferably 250-350 ° C, more preferably 250-330 ° C. The pressure applied is typically 10 to 250 bar, more preferably 25 to 250 bar. Hydrogen can be supplied at a gas hourly space velocity of 100 to 10000 Nl / l / hr, preferably 500 to 5000 Nl / l / hr. The hydrocarbon feedstock may be fed at a space hourly velocity of 0.1 to 5 kg / l / hr, preferably 0.25 to 2 kg / l / hr. The ratio of hydrogen to hydrocarbon feedstock can be 100-5000 Nl / kg, preferably 250-2500 Nl / kg.
As described above for the hydrogenation stage, the degree of hydrocracking and isomerization that occurs in the hydroconversion stage is measured by examining the conversion of the fraction with a boiling point above 370 ° C. as defined above. obtain. Typically, the hydroconversion stage operates at a conversion of 20% or more, preferably 25% or more, but preferably 50% or less, more preferably 45% or less.
[0011]
The hydrogen required for the operation of both the hydrogenation and hydroconversion stages can be produced by methods well known to those skilled in the art, such as steam reforming of refinery fuel gas.
[0012]
The waxy raffinate is then subjected to a pour point depressurization process to lower the pour point to at least -12 ° C, preferably at least -18 ° C, more preferably at least -24 ° C.
Pour point depressing treatments are well known to those skilled in the art and include, for example, solvent dewaxing, catalytic dewaxing, (hydrogenation) isomerization (dewaxing) and / or the addition of pour point depressants. The last-mentioned treatment is usually not preferred for the production of lubricating base oils. This is because the additives contained in the base oil can degrade relatively quickly and blending of various base oils and additive packages to produce the final base oil can be problematic.
[0013]
Catalytic dewaxing is well known to those skilled in the art. In the catalytic dewaxing process, linear paraffins and slightly branched paraffins are decomposed to obtain a product having a boiling point lower than that of the lubricating base oil. However, the catalyst used is not sufficiently selective for wax molecules only. In fact, branched chain paraffins with very high VI and sufficiently low pour points are also broken down into low boiling products. In this way, when these compounds are decomposed into products with boiling points below the range of lubricating base oils, lubricating base oils having a lower VI than lubricating base oils produced by solvent dewaxing processes are formed. The Moreover, the yield of the base oil for lubrication is low compared with solvent dewaxing. Nevertheless, catalytic dewaxing is used commercially because the operating cost of the catalytic dewaxing process is usually lower than that of the solvent dewaxing process.
Catalysts that can be used in the catalytic dewaxing process include zeolites with a constraint index of 1-12, in particular zeolites of the MFI structure type, such as ZSM-5, -11, -22, -23, -35, and Europe. Ferrierite and composite crystalline silicates described in patent applications 0100 115, 0 178 699 and 0 380 180. Another suitable catalytic dewaxing catalyst includes mordenite. If desired, the waxy raffinate feedstock can be divided into various fractions and then the various fractions can be divided into various fractions as described in European Patent Application No. 0 237 655 and European Patent Application No. 0 161 833. You may process separately using a dewaxing catalyst. The catalyst typically comprises one or more catalytically active metals selected from groups VIb, VIIb and VIII of the periodic table.
The catalytic dewaxing process is typically at a temperature of 200-500 ° C., a hydrogen pressure of 5-100 bar, a space velocity of 0.1-5 kg / l / h, and a hydrogen / oil ratio of 100-2500 Nl / kg. carry out.
[0014]
Solvent dewaxing is well known to those skilled in the art, and one or more solvents and / or wax precipitants are mixed with the waxy raffinate and the mixture is −10 ° C. to −40 ° C., preferably −20 ° C. to − Cooling to a temperature in the range of 35 ° C. and separating the wax from the oil. Oil containing wax is usually filtered through a filter cloth, which can consist of textile fibers such as cotton, porous metal cloth, or synthetic cloth.
Specific examples of solvents that can be used in the solvent dewaxing process include C_Three-C₆Ketones (eg methyl ethyl ketone, methyl isobutyl ketone and mixtures thereof), C₆-C_TenAromatic hydrocarbons (eg toluene), mixtures of ketones and aromatics (eg methyl ethyl ketone and toluene), autorefrigerant solvents such as normally gaseous C₂-C_FourExamples include hydrocarbon liquefactions such as propane, propylene, butane, butylene, and mixtures thereof. Usually, a mixture of methyl ethyl ketone and toluene, or a mixture of methyl ethyl ketone and methyl isobutyl ketone is preferred.
The solvent can be recovered from the wax and the lubricating base oil by filtration and recycling of the solvent to the process. However, although the solvent is recycled, the process is still costly because a large amount of solvent is required and a large amount of energy is required to cool the waxy raffinate / solvent mixture.
The wax separated in the solvent dewaxing process can be recycled to the hydroconversion stage, or, for example, if the pour point depressing process includes both a solvent dewaxing stage and a hydroisomerization stage. Can be fed. The wax may be subjected to a deoiling treatment prior to recycling. Alternatively, the wax can be separated and one or more fractions can be sold at the wax market. Fractionation is typically performed using short pass distillation.
[0015]
A very suitable pour point depressing process includes a hydroisomerization process, sometimes referred to in the art as isomerization dewaxing or iso-dewaxing. The hydroisomerization process typically consists of contacting the waxy raffinate with hydrogen in the presence of a hydroisomerization catalyst. Compared with the solvent dewaxing process, the hydroisomerization process has a lower operating cost. Also, the hydroisomerization process is substantially free from the disadvantages of catalyst dewaxing, ie, the lower VI and yield than solvent dewaxing. In the hydroisomerization process, straight-chain paraffins are isomerized into branched-chain paraffins with boiling points in the lubricating base oil boiling range that still have a high VI but a low pour point. Hydroisomerization reactions are preferred, but hydrocracking reactions should be avoided as much as possible. The conversion rate of products with boiling points above 370 ° C. to products below boiling point 370 ° C. is typically less than 25%, preferably less than 20%. This conversion rate usually exceeds 10%.
Thus, it is preferable that the hydroisomerization catalyst used has a large activity for catalyzing a hydroisomerization reaction and a small activity for catalyzing a hydrocracking reaction. To that end, it has been found that the acidity of the catalyst, expressed in alpha value, must be less than 20. The catalyst preferably comprises a molecular sieve. Thus, in a preferred embodiment, the hydroisomerization catalyst comprises a molecular sieve having an alpha value of less than 20, more preferably less than 10 and even more preferably less than 5. The experimental conditions for alpha testing used to determine the alpha values herein include a constant temperature of 538 ° C., J.P. And the variable flow rate detailed in Catalysis, 61, 395 (1980).
[0016]
In one embodiment of the present invention, the molecular sieve that functions in the hydroisomerization operation is preferably a zeolite having a silica / alumina molar ratio of 10 or more, more preferably 30 or more. Zeolites with a high silica / alumina molar ratio usually have lower activity than zeolites with a low silica / alumina molar ratio. A large silica / alumina ratio may be obtained by synthesis of zeolites with a high silica / alumina ratio and / or dealumination treatments such as steaming. Both methods are well known to those skilled in the art. Alternatively, the framework aluminum may be replaced with another trivalent element that reduces acidity, such as boron.
The molecular sieve is preferably selected from among ZSM-12, mordenite and zeolite beta. More preferred is zeolite beta. Low acidity form zeolite beta synthesizes high siliceous form zeolites, eg, zeolites with silica / alumina ratios above 50, or steams low silica / alumina ratio zeolites to the required acidity Can be manufactured. As another method, there is a method in which a part of the framework aluminum of the zeolite is replaced with another trivalent element such as boron. The zeolite preferably contains skeletal boron, typically 0.1% by weight or more, preferably 0.5% by weight or more. Zeolites can also include materials in pores of a structure that do not form part of the framework that constitutes the characteristic structure of the zeolite. As used herein, the term “framework boron” means boron that is actually present in the framework of the zeolite. Unlike the substances present in the pores of the zeolite, skeletal boron contributes to the ion exchange capacity of the zeolite.
Methods for producing zeolites with a high silica / trivalent metal ratio and containing framework boron are disclosed in US Pat. Nos. 4,269,813 and 4,672,049. Typically, the zeolite beta used in the method of the present invention contains 0.1% by weight or more of the boron. The boron content is usually 5% by weight or less, preferably 2% by weight or less. The synthesized zeolite typically has a silica / alumina ratio of less than 30. Preferably, the boron-containing zeolite is steamed to reduce the alpha value to 10 or less, preferably 5 or less. Typical steaming conditions are known and are described in European Patent Application 0 464 547.
Zeolites are usually mixed with a matrix material (binder) to form the final catalyst. Preferred non-acidic refractory oxide binders such as silica, titania or alumina. Particularly preferred is silica. The zeolite is usually mixed with the matrix in an amount of 20 to 80% by weight, preferably 50 to 80% by weight. Methods for extruding zeolite with a binder are known to those skilled in the art.
[0017]
In another embodiment of the invention, the molecular sieve is an aluminophosphate. Aluminophosphates are well known to those skilled in the art and are described, for example, in U.S. Pat. Nos. 4,310,440, 4,440,871, 4,567,029 and 4,793,984. Aluminophosphate has the advantage of lower natural acidity compared to zeolite.
Aluminophosphate herein is understood to mean aluminophosphates, ie metallo-aluminophosphates, silico-aluminophosphates, metallo-silico-aluminophosphates as well as non-metal substituted aluminophosphates and silico-aluminophosphates. .
Since the molecular sieve preferably has at least some natural acidity, the aluminophosphate is a metallo-aluminophosphate, silico-aluminophosphate or metallo-phosphate in which the other metal present in the aluminophosphate backbone is not a trivalent metal. Choose from silico-aluminophosphates. In a particularly preferred embodiment, the aluminophosphate is silico-aluminophosphate.
In certain embodiments, the process of the present invention is carried out using a hydroisomerization catalyst selected from among structural types 11, 31 and 41, more preferably an aluminophosphate of structural type 11, in particular silico-aluminophosphate. Is preferred. Silico-aluminophosphates of structure types 11, 31 and 41 are described in international patent application WO 90/09362. In a particularly preferred embodiment of the invention, the hydroisomerization catalyst consists of a structural type 11 silico-aluminophosphate having a special silica / alumina distribution on the crystalline particles. In particular, silico-aluminophosphate molecular sieves are characterized by the X-ray diffraction pattern shown in Table I.
[0018]
[Table 1]

[0019]
Symbol I / I in the table₀* 100 represents relative intensity, I₀Is the intensity of the strongest line, and d is the lattice spacing (unit angstrom) corresponding to the recorded line. X-ray powder diffraction patterns can be measured by standard methods using K-alpha / double-line copper irradiation.
The silico-aluminophosphate is also a surface P₂O_FiveThe molar ratio of alumina to alumina is 0.80 or less, and the silico-aluminophosphate body (bulk) P₂O_FiveThe molar ratio of alumina to alumina is greater than 0.96 and the molar ratio of surface silica to alumina is greater than that of the silico-aluminophosphate body. This silico-aluminophosphate is known in the art as SM-3. The production of SM-3 is disclosed in international patent application WO 91/13132.
[0020]
In yet another embodiment of the invention, the isomerization catalyst comprises a non-layered inorganic porous crystalline phase material, as described in International Patent Application WO 93/02161.
The hydroisomerization catalyst typically comprises catalytically active metals having hydrogenation / dehydrogenation activity, such as Group VIb and Group VIII metals. The hydroisomerization catalyst preferably comprises a Group VIII metal, in particular a Group VIII noble metal such as platinum and / or palladium. Means for including a metal in a catalyst support including a molecular sieve as described above are well known to those skilled in the art and have already been described. The amount of noble metal is typically in the range of 0.5-5% by weight of the total catalyst, preferably 0.5-2%.
[0021]
In the hydroisomerization stage of the process of the present invention, the waxy raffinate is contacted with hydrogen at an elevated temperature and pressure in the presence of the aforementioned catalyst. Typically, the temperature required to obtain a lubricating base oil is 175-380 ° C, preferably 200-350 ° C. The pressure usually applied is 10 to 250 bar, more preferably 25 to 250 bar. The waxy raffinate can be fed at a space hourly velocity of 0.1 to 20 kg / l / hr, preferably 0.1 to 5 kg / l / hr.
The final lubricating base oil preferably has a pour point of less than −15 ° C., more preferably less than −20 ° C., and has a VI greater than 135, preferably greater than 140. The base oil for lubrication that has been hydrogenated, hydroconverted and hydroisomerized preferably does not require further pour point depressing treatment. However, it may be desirable to isomerize the waxy raffinate to an intermediate pour point and solvent dewax the isomerized waxy raffinate to the final pour point.

Claims (33)

  The process comprising subjecting a waxy raffinate to a pour point depressurization and recovering a lubricating base oil therefrom, wherein the waxy raffinate is a hydrogenated / dehydrogenated hydrocarbon product supported on a refractory oxide support. A waxy raffinate by contacting with hydrogen in the presence of a hydroconversion catalyst comprising a catalytically active metal having activity under conditions such that hydrocracking and hydroisomerization of said hydrocarbon product occurs. Wherein the hydrocarbon product produces (a) a mixture of carbon monoxide and hydrogen with a hydrocarbon synthesis catalyst at high temperature and pressure to produce a substantially paraffinic hydrocarbon wax; b) contacting the resulting hydrocarbon wax with hydrogen in the presence of a hydrogenation catalyst under conditions such that isomerization or hydrocracking of said hydrocarbon wax does not occur substantially to yield a hydrocarbon product. Made by getting In which the method for producing a lubricating base oil.   The hydrogen / carbon monoxide ratio of the mixture of carbon monoxide and hydrogen that contacts the catalyst in step (a) is less than 2.5, preferably less than 1.75, more preferably 0.4 to 1.5. The method according to claim 1.   The process according to claim 1 or 2, characterized in that the hydrocarbon synthesis catalyst of step (a) comprises ruthenium, iron, nickel or cobalt, preferably cobalt as the catalytically active metal.   The hydrocarbon synthesis catalyst of step (a) preferably comprises a support selected from silica, alumina, titania, zirconia and mixtures thereof, most preferably a support consisting of silica or alumina. 4. The method according to any one of items 1 to 3.   The hydrocarbon synthesis catalyst of step (a) comprises, as a promoter, an oxide of a metal selected from group IVB of the periodic table of elements, preferably an oxide of titanium or zirconium. The method according to any one of the above. 6. The mixture of carbon monoxide and hydrogen in step (a) is brought into contact with the catalyst at a temperature of 100 [ deg.] C. to 300 [deg.] C., preferably 150 [ deg.] C. to 275 [ deg.] C. the method of.   7. The carbon monoxide and hydrogen mixture in step (a) is contacted with the catalyst at a pressure of 5 to 100 bar, preferably 12 to 50 bar, according to any one of the preceding claims. Method.   The hydrogenation catalyst of step (b) comprises as the catalytically active metal molybdenum, tungsten, cobalt, nickel, ruthenium, iridium, osmium, platinum or palladium, preferably one or more of nickel, platinum and palladium; 8. A method according to any one of the preceding claims, characterized in that it is characterized in that   The hydrogenation catalyst of step (b) preferably comprises a support selected from silica, alumina, silica-alumina, zirconia, titania and mixtures thereof, preferably a support consisting of silica, alumina or silica-alumina. The method according to any one of claims 1 to 8. 10. Process according to claim 8 or 9, characterized in that the hydrogenation catalyst comprises nickel in an amount of 30 to 70 parts by weight per 100 parts by weight of support material. The process according to claim 8 or 9, characterized in that the hydrogenation catalyst comprises platinum in an amount of 0.05 to 2 parts by weight per 100 parts by weight of support material. 12. The hydrocarbon product according to any one of claims 1 to 11 , characterized in that in step (b) the hydrocarbon product is contacted with a hydrogenation catalyst at a temperature of 100C to 300C, preferably 150C to 275C. Method. 13. Process according to any one of claims 1 to 12 , characterized in that in step (b) the hydrocarbon product is contacted with the hydrogenation catalyst at a pressure of 5 to 150 bar, preferably 10 to 50 bar. Step (b) in 100~10000Nl hydrogen / l / hr, preferably according to any one of claims 1 to 13, characterized by supplying a gas hourly space velocity of 250~5000Nl / l / hr Method. Conversion of less than 10% in step (b), the method according to any one of claims 1 to 14, characterized in that more preferably less than 5%. The hydroconversion catalyst comprises as a catalytically active metal molybdenum, tungsten, cobalt, nickel, ruthenium, iridium, osmium, platinum or palladium, preferably one or more of nickel, platinum and palladium. Item 16. The method according to any one of Items 1 to 15 . The hydroconversion catalyst preferably comprises a support selected from silica, alumina, silica-alumina, titania, zirconia and mixtures thereof, preferably a support consisting of silica, alumina or silica-alumina. Item 17. The method according to any one of Items 1 to 16 .   The process according to claim 15, characterized in that the hydroconversion catalyst comprises a halogen-containing support. One hundred seventy-five to three hundred and eighty ° C. The hydrocarbon product, preferably the method according to any one of claims 1 to 18, characterized in that contacting with the hydroconversion catalyst at a temperature of 250 to 350 ° C.. The hydrocarbon products from 10 to 250 bar, preferably the method according to any one of claims 1 to 19, wherein the contacting with the hydroconversion catalyst at a pressure of 25 to 250 bar. In hydroconversion step, hydrogen 100 to 10000 Nl / l / hr, preferably according to claims 1, wherein the supplying a gas hourly space velocity of 500 to 5000 Nl / l / hr to any one of the 20 the method of. The method according to any one of claims 1 to 21 , wherein the conversion rate in the hydroconversion step is 20% or more. 23. A process according to any one of claims 1 to 22 , wherein the pour point depressing treatment comprises contacting the waxy raffinate with hydrogen in the presence of a hydroisomerization catalyst. 24. A process according to claim 23 , characterized in that the hydroisomerization catalyst comprises a molecular sieve and the catalyst has an alpha value of less than 20, preferably less than 10. 25. Process according to claim 24 , characterized in that the molecular sieve is a zeolite with a silica / alumina molar ratio of preferably 10 or more. 26. Process according to claim 24 or 25 , characterized in that the molecular sieve is selected from among ZSM-12, mordenite and zeolite beta, preferably zeolite beta. The method of claim 24 , wherein the molecular sieve is an aluminophosphate. 28. The method of claim 27 , wherein the aluminophosphate is silico-aluminophosphate. 29. Process according to claim 27 or 28 , wherein the aluminophosphate is selected from among structural types 11, 31 and 41, preferably of structural type 11. Hydroisomerization catalyst, VIB group and / or selected catalytically active metal from Group VIII of the Periodic Table of Elements, or preferably one of claims 1, characterized in that it comprises one or more noble metals of Group VIII 29 one The method according to item. The waxy raffinate is produced from a product having a boiling point of more than 370 ° C. to a boiling point of less than 370 ° C. at a temperature of 175 to 380 ° C. and a pressure of 10 to 250 bar in the presence of a hydroisomerization catalyst comprising a molecular sieve and a Group VIII noble metal. Hydroisomerization process comprising the step of contacting said waxy raffinate with hydrogen such that the conversion to product is less than 25% and recovering a lubricating base oil having a pour point of less than -20 ° C therefrom. The waxy raffinate is subjected to a catalytic action having a hydrogenation / dehydrogenation activity on a hydrocarbon product supported on a refractory oxide support. In contact with hydrogen in the presence of a hydroconversion catalyst comprising an active metal and under conditions such that hydrocracking and hydroisomerization of the hydrocarbon product occur at a conversion rate of 25% or more. The hydrocarbon product is obtained by contacting a mixture of carbon monoxide and hydrogen with a hydrocarbon synthesis catalyst at high temperature and pressure at a substantially paraffinic carbonization. Hydrogen wax is produced, (b) the resulting hydrocarbon wax is converted to a fraction having a boiling point of less than 370 ° C. in the presence of a hydrogenation catalyst at a temperature of 100-300 ° C. and above 370 ° C. 31. The process according to any one of claims 23 to 30, wherein the hydrocarbon product is produced by contacting with hydrogen under conditions such that the weight percent of the boiling fraction is less than 10%. The method described. The method according to any one of claims 1 to 22 , wherein the pour point depressing treatment comprises a solvent dewaxing treatment or a catalyst dewaxing treatment. A base oil for lubrication produced by the method according to any one of claims 1 to 32 .