KR20050061521A - Heavy lube oil from fischer-tropsch wax - Google Patents

Abstract

A heavy lubricant base stock is made by (a) producing a synthesis gas from natural gas, (b) reacting the H2 and CO in the gas in the presence of a cobalt Fischer-Tropsch catalyst, at reaction conditions effective to synthesize waxy hydrocarbons boiling in the heavy lubricant oil range, which are hydrodewaxed it at least two stages, with interstage separation and removal of the lighter material.

Description

HEAVY LUBE OIL FROM FISCHER-TROPSCH WAX} from Fischer-Tropsch wax

The present invention relates to a multi-step process for producing heavy lubricants from Fisher-Tropsch waxes. More specifically, the present invention provides a method for the present invention by hydrodewaxing a wax in multiple stages while separating and removing a hard material in an intermediate stage from the wax synthesized by reacting H ₂ and CO prepared from natural gas in the presence of a cobalt Fischer-Tropsch catalyst. A method for making a heavy lubricant base stock.

The relatively pure waxy paraffinic hydrocarbons synthesized via the Fischer-Tropsch process, in particular cobalt catalysts to maximize the production of high molecular weight hydrocarbons, are excellent raw materials for higher lubricating oils, including heavy lubricants. The content of sulfur, nitrogen and aromatics in the waxy hydrocarbons is essentially inherent and thus the raw hydrocarbons can pass the upgrade operation without prior hydrogenation treatment. In the Fischer-Tropsch process, H ₂ and CO in the synthesis gas source are reacted in the presence of a hydrocarbon synthesis catalyst to produce a range of lubricating oils comprising a heavy lubricant range of 850 ° F. + (454 ° C. +) when produced via cobalt catalyst. Wax hydrocarbons are formed that contain actual measurements of the waxy normal paraffinic hydrocarbons having boiling points. Fischer-Tropsch wax refers to a waxy hydrocarbon fraction that is typically removed from a synthesis reactor, such as a liquid, which is a solid at ambient room temperature and pressure conditions. Heavy lubricant fractions require extensive dewaxing to produce heavy lubricant based stocks having acceptable cloud and pour points. Due to its solid waxy at ambient conditions, the solvent dewaxing process cannot be used.

Various processes are disclosed for catalytically dewaxing these and other waxy hydrocarbons. Many processes, such as those using ZSM-5 catalysts, dehydrowax waxy hydrocarbons to products with boiling points below the lubricating oil range by hydropyrolysis. In addition, a manual process for removing heteroatoms and aromatics is required. Illustrative examples of various catalytic dewaxing processes include, but are not limited to, for example, US Pat. Nos. 6,179,994, 6,080,301, 6,090,989, 6,051,129, 5,689,031, and 5,075,269; And European Patent No. 0 668 342 B1. Dewaxing the heavy lubricating oil fraction into an acceptable cloud point causes problems in the water process and worsens low production yields. There is a need for a process for increasing the yield of dewaxed heavy lubricant base stock made from Fischer-Tropsch wax.

Summary of the Invention

The present invention provides a heavy lubricant substrate stock by hydrodewaxing Fischer-Tropsch wax with heavy hydrocarbons having boiling points in the heavy lubricant range in multiple stages (e.g. two or more stages) while separating and removing the hard material in an intermediate stage. It relates to a method of manufacturing. More generally, heavy lubricant based stocks have a boiling point in the range of heavy lubricating oils, where (a) a synthetic gas is produced from natural gas, and (b) hydrodewaxed in at least two stages, separating and removing the hard material in an intermediate stage. It is prepared by reacting H ₂ and CO in the presence of a cobalt Fischer-Tropsch catalyst under reaction conditions effective to synthesize waxy hydrocarbons having. Another embodiment of the invention is (a) preparing a synthetic gas from natural gas; (b) reacting H ₂ and CO in gas in the presence of a cobalt Fischer-Tropsch catalyst under reaction conditions effective to synthesize a waxy hydrocarbon comprising fractions having a boiling point in the range of heavy lubricants; (c) hydro-waxing one or more waxy heavy lubricating oil hydrocarbon fractions in two or more stages while removing hydrocarbons having a lower boiling point than the separated heavy lubricating oil fractions in two or more stages to improve flexibility to produce a heavy lubricant base stock. It is about a method. The process of converting natural gas into synthetic gas, that is, converting into hydrocarbon, is referred to as gas conversion process. Thus, this embodiment refers to a gas conversion process plus the product enhanced by hydrodewaxing. The hydrodewaxing process (i) hydrodewaxes the wax or waxy feed to produce isomers comprising a partially dewaxed heavy lubricant fraction and a low boiling hydrocarbon fraction, and (ii) these two fractions And, (iii) further hydrodewaxing the partially hydrodewaxed heavy lubricant fraction in one or more additional steps to produce a heavy lubricant base stock.

Hydrodewaxing means that the waxy source and the partially dewaxed heavy lubricating oil fraction are contacted with a hydrodewaxing catalyst which is mainly dewaxed by hydrogen isomerization rather than hydrogen and hydrogenohydrolysis. It excludes a dewaxing catalyst, such as ZSM-5, and is mainly waxed by hydropyrolysis of waxy molecules, especially heavy lubricant fractions, with hydrocarbons having a boiling point below the desired product range. Hydrodewaxing catalysts and hydrogenation components comprising ZSM-48 zeolites (here, ZSM-48 zeolites comprise structural equivalents EU-2, EU-11 and ZBM-30) are particularly useful in the process of the present invention. It has been found useful and can be used in one or more, preferably all hydrodewaxing reaction steps. Heavy lubricant fraction refers to a hydrocarbon having an initial boiling point of about 850-950 ° F. (454-510 ° C.) and a terminal boiling point above 1,000 ° F. (538 ° C.). The heavy lubricant base stock has an initial boiling point of at least about 850 ° F. (454 ° C.) and a terminal boiling point of 1,000 ° F. (538 ° C.), preferably 1050 ° F. (566 ° C.) and is the first of the multistage hydrodewaxing process of the present invention. It has a lower cloud point and pour point than that obtained by the raw, unprocessed heavy fraction in the Fischer-Tropsch wax feed introduced in the step and any other step between the first and final hydrodewaxing step. The initial and terminal boiling point values mentioned herein are very small and refer to the T5 and T95 cut points obtained by gas chromatography distillation (GCD) using the method disclosed below. Partially dewaxed heavy lubricant fraction means that the heavy lubricant fraction is not as low as the desired pour point, but is hydrogen dewaxed to lower the pour point than before the partial dewaxing, which is one or more of the following successive This is achieved by further dewaxing the partially fractionated heavy fractions in the hydrodewaxing reaction step.

The hydrogenation component of the hydrodewaxing catalyst comprises at least one Group VIII metal, preferably at least one precious metal such as platinum and palladium. The use of hydrogen dewaxing catalysts (e.g., ZSM-48 and precious metal components) which are mainly dewaxed by two or more reaction steps and isomerization results in relatively high product yields (e.g., lower boiling points than the range of heavy lubricants). It has been found to produce heavy lubricant based stocks with acceptable low cloud and pour points) with relatively low feed conversion to hydrocarbons having). Only one hydroisomerization step is used to convert substantially more heavy fractions into low-boiling hydrocarbons and thus the required heavy weights, even with a hydrodeswaxing catalyst comprising a ZSM-48 zeolite component and a noble metal hydrogenation component. It has been found to produce little lubricant based stock oil. The multistage hydroisomerization process of the present invention also allows each step to operate at lower temperatures than required in a single step. This leads to the production of lubricant based stocks that contain longer catalyst life and aromatic and other unsaturated materials than are possible by using a single step. This means that at most very mild substrate stock modifications are required, which is another advantage of the process of the present invention.

The process of the present invention is particularly useful for producing heavy lubricant based stock oils having low cloud and pour points. Process of water treatment or modification of raw raw untreated Fischer-Tropsch wax source to remove oxygenation prior to dewaxing by use of a hydrogen dewaxing catalyst comprising a ZSM-18 zeolite component and a hydrogenation component This is not necessary. The process of the present invention is disclosed in the art and substantially reduces the product yield, in particular the yield of the required heavy lubricant base stock, at least one separate hydropyrolysis, hydroisomerization and catalyst or solvent desulfurization prior to hydrodewaxing. The need for a waxing step is omitted.

The hydrowaxing process of the present invention includes two or more hydrowaxing steps as described above. The raw Fischer-Tropsch wax feed prepared by the cobalt catalyst, preferably a non-shifting cobalt catalyst, may be subjected to aromatic, unsaturated or heteroatoms (oxygenates) prior to the first hydrodewaxing step. To be removed). These waxes or waxy Fischer-Tropsch synthesized hydrocarbons (these terms are used synonymously herein) include a heavy lubricant fraction and a boiling point hydrocarbon fraction that are hydrowaxed and partially dewaxed in a first step. To produce an isomeric effluent. This partially dewaxed heavy lubricant having a lower cloud point and pour point than the heavy lubricant fraction in the wax feed is subjected to a second step which is separated from the low boiling hydrocarbon and further hydrodewaxed. The second hydrodewaxing step produces an isomeric effluent comprising (i) a heavy lubricating oil fraction having a lower cloud point and pour point than that prepared in the first step and (ii) a hydrocarbon having a low boiling point. The heavy lubricant fraction is separated from the hydrocarbon with low boiling point. In embodiments where only two stages are used, the heavy lubricant isomers prepared in the second stage include heavy lubricant base stocks having the required cloud and pour points. When three steps are used, the heavy lubricant isomers separated in the second step undergo a third step for more hydrogen dewaxing to produce a heavy lubricant base stock and the like. Thus, the wax source only goes through the first step. The partially hydrodewaxed heavy lubricating oil isomeric fractions prepared in the first stage are sequentially passed through the second and any successive stages to the required pour point and / or cloud point while separating the fractions having heavy and low boiling points in the intermediate stage. Hydrodewaxed heavy lubricant based stock is prepared. By step is meant one or more hydrodewaxing reaction zones without interregional separation of the reaction product, and typically, but not necessarily, refers to a separate hydrodewaxing reactor. Heavy lubricant base stocks produced by this process are typically de-clouded and / or processed in mild conditions to improve color and stability to form processed lubricant base stocks. As is known, turbidity is a blur or loss of transparency, which is an appearance factor. Declouding is typically obtained by removing components that cause clouding by catalytic or absorbent methods. Hydroprocessing is a very mild relatively cold hydrogenation process that uses catalyst, hydrogen, and mild reaction conditions to remove small amounts of heteroatomic compounds, aromatics and olefins to improve oxidation stability and color. The hydroprocessing reaction conditions include a temperature of 302 to 662 ° F. (150 to 350 ° C.), preferably a temperature of 302 to 550 ° F. (150 to 288 ° C.), a total pressure of 400 to 3000 psig (2859 to 20786 kPa), 0.1 to 5 LHSV (hr ^{−). 1} ), preferably liquid hourly space velocity of 0.5 to ³ hr ⁻¹ . Oxygen treatment gas rate will be from 250 to 10000 scf / B (44.5 to 1780m ³ / m ^3). The catalyst will comprise a support component and at least one catalytic metal component of Group VIB metals (Mo, W, Cr) and / or a group of iron (Ni, CO) and / or a noble metal (Pt, Pd) of group VIII. Groups VIB and VIII referred to herein refer to Groups VIB and VIII as shown in the Sazen-Welch Periodic Table of Elements All rights reserved in 1968 by Sargent-Welch Scientific Company. will be. The metal or metals may be present in as little as 30% by weight of the non-noble metal of the catalyst composition from as little as 0.1% by weight of the precious metal. Preferred support materials are low in acid and include, for example, primary pore crystalline materials known as amorphous or crystalline metal oxides such as alumina, silica, silica alumina and mesoporous crystalline materials, MCM- 41 is a preferred support component. Formulations and the use of MCM-41 are disclosed, for example, in US Pat. Nos. 5,098,684, 5,227,353, and 5,573,657.

In the practice of the present invention, the separation in the intermediate stage during the hydrodewaxing cannot be precise, so that the separated heavy fractions which have undergone the subsequent hydrodewaxing step are in small amounts (eg less than 50% by weight, preferably Hydrocarbons having a low boiling point of less than 25%, more preferably less than 5% by weight). After the first step, it is preferred that the amount of low boiling hydrocarbons maintained in the separated heavy fractions undergoing the second optional continuous step is as low as possible. This will be determined by the type of separation used (eg flashing or fractionation) and the requirements of the process. At each step, a portion of the heavy lubricant fraction is lost by conversion to hydrocarbons having a boiling point below the heavy lubricant boiling range. However, as shown in the examples below, the combination of the multistage hydrogen dewaxing process of the present invention and the use of a dewaxing process comprising a ZSM-48 zeolite component, preferably a noble metal hydrogenation component, uses only a single step. In comparison, the loss of this beneficial lubricant is minimized.

In the hydrodewaxing reaction, the pour point and cloud point are lowered mainly by the isomerization of high molecular weight hydrocarbon molecules. Isomerization is carried out in the presence of hydrogen, but pure hydrogen consumption in purely isomerization reaction. Intermediate and final separation of heavy lubricant hydrocarbons from low boiling hydrocarbons is achieved by flashing or flashing. Hydrodewaxing reaction conditions used in the process of the present invention include a temperature of 450 to 750 ° F. (232 to 399 ° C.), a hydrogen partial pressure of 10 to 2,000 psig. (69 to 13790 kPa) and a space velocity of 0.1 to 5.0 LHSV. Each covers a wide range. These conditions are more generally 500-700 ° F. (260-371 ° C.), 100-1000 psig. (690-6895 kPa) and 0.5-3.0 LHSV, and more typically 200-700 psig. (1379-4827 kPa).

The heavy lubricant based stock of the present invention has a kinematic viscosity of at least 8 sSt (centistoke) at 100 ° C. and has an initial boiling point of at least about 850 to 950 ° F. (454 to 510 ° C.) and greater than 1,000 ° F. (538 ° C.), typically 1050 ° F. (566 ° C.). Dewaxed oil with a terminal boiling point greater than). It has a low temperature characteristic that can meet the target workpiece or requirements. Its pour point and cloud point are lower than those of the heavy lubricating oil fraction in the wax feed and any hydrodewaxing stage upstream of the final stage. Pour point is lower than cloud point. Heavy lubricant based stocks are typically clear and light oily liquids under pressure conditions of room temperature and 75 ° F. (24 ° C.) and 1 atmosphere (101 kPa). However, in some cases the cloud point may be higher than 75 ° F. (24 ° C.). Heavy lubricant base stocks having a cloud point and pour point of 1 ° C. and −31 ° C., respectively, and a terminal boiling point above 1,250 ° F. (677 ° C.) are prepared according to the present invention. The low temperature properties requirements of both the heavy lubricant base stock and the processed lubricant can vary and depend on the application to the desired geographic location where the lubricant is used. Lubricant or processed lubricant product (both of these terms are used synonymously herein) refers to a heavy lubricant based stock disclosed herein and an additive package containing an effective amount of one or more additives or more typically one or more additives. It is prepared by forming a mixture. Illustratively, such additives include one or more detergents, dispersants, antioxidants, antiwear additives, superpressure additives, pour point depressants, VI enhancers, friction modifiers, demulsifiers, antioxidants, antifoams, corrosion inhibitors, and seals. Expansion control additives include, but are not limited to. Heavy lubricant based stocks used to form the mixture are typically those that are mildly hand-processed and optionally de-clouded after hydrodewaxing to improve their color, appearance and stability.

The waxy feed or wax fed to the first hydrodewaxing step comprises all or part of the waxy hydrocarbon fraction produced in the Fischer-Tropsch hydrocarbon synthesis reactor, which is liquid at reaction conditions. It must contain hydrocarbons having a boiling point above 1000 ° F. (538 ° C.) to prepare the heavy lubricant stock composition of the present invention. Under the Fischer-Tropsch hydrocarbon synthesis process and non-mobile conditions where H ₂ and CO react under mobile or non-mobile conditions to form hydrocarbons, especially when the catalytic metal comprises CO, little or no water gas shift reaction occurs. It is known that liquid and gaseous hydrocarbon products in the process of the invention, which does not occur, are formed by contacting a synthesis gas comprising a mixture of H ₂ and CO with a Fischer-Tropsch catalyst. Syngas typically contains less than 0.1 vppm, preferably less than 50 vppb, of sulfur or nitrogen in the form of one or more sulfur and nitrogen containing compounds. Methods of removing nitrogen and sulfur from syngas and reducing them to very low levels are known and are described, for example, in US Pat. Nos. 6,284,807, 6,168,768, 6,107,353 and 5,882,614. In the process of the present invention, the cobalt Fischer-Tropsch catalyst is characterized in that at least one of Re, Ru, Ni, Th, Zr, Hf, U, Mg and La, on catalytically effective amounts of CO and optionally suitable inorganic support materials, It preferably includes one or more refractory metal oxides. Preferred supports for CO containing catalysts include titania, particularly when using slurry hydrocarbon synthesis processes that require high molecular weight, usually paraffinic, liquid hydrocarbon products. Useful catalysts and their formulations are known and can be found, for example, but not limited to, for example, US Pat. Nos. 4,568,663, 4,663,305, 4,542,122, 4,621,072, and 5,545,674. Fixed bed, fluidized bed and slurry hydrocarbon synthesis processes are known and disclosed in the literature. In all these processes, the synthesis gas reacts in the presence of Fischer-Tropsch of a suitable hydrocarbon synthesis catalyst at effective reaction conditions for forming hydrocarbons. Some of these hydrocarbons will be liquids, some solids (eg waxes) and some gases at standard room temperature conditions and 25 ° C. and 1 atmosphere (101 kPa). Slurry Fischer-Tropsch hydrocarbon synthesis processes are often preferred when cobalt catalysts, preferably non-mobile cobalt catalysts, can be used to produce more relatively high molecular weight paraffinic hydrocarbons useful for lubricant and heavy lubricant based stocks. To achieve this, the synthesis reactor is at least 700 ° F. + (371 ° C.) hydrocarbons per 100 lbs. CO converted to 14 lbs. Or more, preferably 700 ° F. + (371 ° C.) for each 100 pounds of CO converted to hydrocarbons. It is operated under conditions that produce at least 20 pounds of hydrocarbons. Preferably less than 10 pounds of methane are formed for each 100 pounds of CO converted. This high degree of 700 ° F. + (371 ° C.) hydrocarbon production is achieved in slurry hydrocarbon synthesis reactors using catalysts having rhenium promoted cobalt and titania supported components. By no shift is meant that less than 5% by weight, preferably less than 1% by weight, of carbon in the feed CO is converted to CO ₂ .

In a hydrocarbon synthesis process carried out under non-moving conditions using a cobalt catalyst, the molar ratio of H ₂ to CO in the synthesis gas is preferably a stoichiometric consumption molar ratio, typically about 2.1 / 1. H ₂ and the synthesis gas comprising a mixture of CO, H ₂ and CO is Fischer-Tropsch fraction is liquid at the reaction conditions in the presence of a composite catalyst conditions effective to form hydrocarbons (including hydrocarbon slurry liquid in a slurry reactor) Through the reactor at In slurry reactors, synthetic hydrocarbon liquids are separated from catalyst particles by means such as simple filtration, although other separation means may be used as filtrate. Some of the synthesized hydrocarbons are vaporized and removed via a hydrocarbon synthesis reactor along with unreacted syngas and gaseous reaction products as overhead gases. Some of this overhead hydrocarbon vapor is typically condensed into a liquid and combined with a hydrocarbon liquid filtrate. Thus, the initial boiling point of the synthesized hydrocarbon as liquid to be removed from the reactor can be varied by whether or not it combines with some of the condensed hydrocarbon vapors. Hydrocarbon synthesis process conditions are somewhat varied by catalyst, reactor, and desired product. In fixed bed or slurry hydrocarbon synthesis processes using catalysts comprising supported cobalt components usually form hydrocarbons comprising C ₅₊ paraffins (eg C ₅₊ -C ₂₀₀ ), preferably C ₁₀₊ paraffins. Typical conditions effective for this are, for example, temperatures of about 320 to 600 ° F. (160 to 315.6 ° C.), pressures of 80 to 600 psig (552 to 4137 kPa) and gaseous CO and H ₂ mixtures per hour of volume of catalyst (60 ° F. (15.6), for example. ° C), 1 atm) and a gas space velocity of 100 to 40,000 V / hr / V, expressed as a standard volume. In the practice of the present invention, waxy hydrocarbons or wax feeds may be prepared in slurry, immobilized or fluidized bed Fischer-Tropsch reactors.

A portion of the hydrocarbons synthesized in the Fischer-Tropsch hydrocarbon synthesis reactor, normally gaseous or vapor at the reaction conditions, is typically discharged into the liquid effluent. The vaporous effluent from the Fischer-Tropsch hydrocarbon synthesis reactor can be cooled to concentrate and recover a portion of the synthesized hydrocarbon that is steam at the reaction conditions, and all or part of this concentrate can be combined with the liquid effluent. Thus, the initial boiling point of the wax may vary depending on the reactor, catalyst, conditions, amount of condensate combined with the liquid effluent and the desired product slate. This may cause some change in the composition. The entire wax fraction removed from the synthesis reactor as a liquid (eg 400 to 450 ° F. + (204 to 232 ° C. +) may be fed to the first hydrodewaxing step. It can be removed from the wax before it is introduced into the hydrodewaxing step, therefore, in the process of the invention, the wax fed to the first hydrodewaxing reactor is continuously boiling or boiling from its initial boiling point to its terminal boiling point. In addition, if desired, all, almost or only a portion of the low boiling point material may be removed from the wax prior to hydrodewaxing, which has an initial boiling point of the wax feed from about 400 to 450 ° F. to 800 ° F. 427 ° C.) or more.

By way of example, but not by way of limitation, the wax is prepared in a slurry Fischer-Tropsch reactor containing a rhenium-promoted cobalt catalyst with a titania support component and has an initial of about 430-450 ° F. (221-232 ° C.). Has a boiling point. Low-boiling naphtha hydrocarbons (C ₅₊ 430 to 450 ° F. or less) produced by the synthesis reaction do not combine with the high boiling liquid reactor effluent. Such waxes comprise more than 90% by weight of paraffin, 2 to 4% by weight of oxygenate and 2 to 5% by weight of olefin and vary with reaction conditions. Aromatics are not detected by NMR analysis. The wax contains less than 1 wpm sulfur and less than 1 wpm nitrogen. The weight percentage of oxygen from the oxygenate is measured by neutron activation in combination with high resolution ¹ H-NMR. The total oxygen content can be based on water-bonsai by measuring the water content using calcium carbide (which forms acetylene) and performing GC-MS when the water content is less than about 200 wppm. For over 200 wppm water content the Karl-Fischer method in ASTM standard D-4928 is used. Aromatics are measured by X-ray fluorescence (XRF) as described in ASTM standard D-2622. Sulfur is measured by XRF as sugar per ASTM standard D-2622 and nitrogen is measured by syringe / inlet combustion oxide using chemiluminescent detection per ASTM standard D-4629.

Fischer-Tropsch wax feeds and two or more hydrodewaxing reaction steps together with intermediate stage removal of hydrocarbons having boiling points below the heavy lubricating oil range are essential features of the present invention. Hydrodewaxing catalysts comprising a hydrogenation component, a solid acid component and a binder (zeolite catalyst), preferably in hydrogen form, are used in one or more reaction stages.

Illustratively, suitable catalyst components useful for hydrodewaxing include, for example, ZSM-23, ZSM-35, ZSM-48, ZSM-57, ZSM-22, and SAPO (e.g. Silica alumino-phosphate, SSZ-32, zeolite beta, mordenite and rare earth ion exchanged ferrierites known as SAPO-11, 31 and 41). Also useful are alumina and amorphous silica alumina.

As in the case of many other zeolite catalysts, it may be desirable to incorporate the solid acid component with matrix materials known as binders that are resistant to the temperatures and other conditions used in the dewaxing process herein. Such matrix materials include active and inert materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and / or metal oxides such as alumina. The latter may be naturally occurring or in the form of gelatinous precipitates, sols or gels comprising a mixture of silica and metal oxides. The use of a substance conjugated with an active solid acid component, ie a substance bound thereto, can enhance the conversion and / or selectivity of the catalyst herein. The inert material suitably acts as a diluent to control the amount of conversion in a given process so that the product is obtained economically and orderly without using proportions or other means to control the reaction. Often, crystalline silicate materials are incorporated into naturally occurring clays such as bentonite and kaolin. Such materials, namely clays, oxides, etc., function as binders for some catalysts. In petroleum refineries it is desirable to provide a catalyst with good breaking strength because the catalyst often performs rough handling which tends to destroy the catalyst, which degrades into a powder-like substance that causes problems during the process.

Naturally produced clays that can be combined with the solid acid component include sub-bentonite and kaolin known as Dixie, McNamee, Georgia and Florida clays. Montmorillonite and other components wherein the kaolin-based or main mineral component is halosite, kaolinite, dicide, nacrite or anoxite. Such clays can be used as they are in the original raw materials or initially subjected to calcining, acid treatment or chemical modification.

In addition to the materials described above, the solid acid component may be formed into a pore matrix material such as silica-alumina, silica-magnesia, silica-zirconia, silica-toria, silica-berilia, silica-titania, as well as ternary compositions such as silica- Alumina-toria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. The matrix may be in the form of a cogel. Mixtures of these components may be used. The relative fractions of the finely separated solid acid component and inorganic oxide gel matrix vary widely with the crystalline silicate content of about 1 to about 90 weight percent, more generally about 2 to about 80 weight percent of the composite.

Preference is given to using a hydrodewaxing catalyst comprising a ZSM-48 zeolite component and a hydrogenation component (ZSM-48 catalyst) in at least one step. This may be one of two or more steps. In a more preferred embodiment, the ZSM-48 catalyst is used at all stages. In this embodiment, the ZSM-48 catalyst is used to hydrodewax a waxy feed containing a heavy lubricant fraction and one or more heavy lubricant isomers prepared in subsequent steps. The hydrogenation component will contain one or more Group VIII metal components, preferably Group VIII precious metal components such as Pt and Pd. The concentration of the noble metal will be about 0.1 to 5%, more typically 0.2 to 1% by weight of the metal based on the total catalyst weight, including the ZSM-48 zeolite component and any binder used in the catalyst composition. The Group VIII referred to herein refers to the Group VIII as shown in the Sazen-Welch Periodic Table, which was copyrighted in 1968 by the Sazen-Welch Scientific Company. Hydrodewaxing experiments carried out using Fischer-Tropsch waxes show that all rare earth ion exchange ferrierites, mordenites, zeolite beta, SAPO-11, TON, in which the ZSM-48 catalyst uses for example Pt hydrogenation components And other materials including ZSM-23. It is also superior to Pd / amorphous silica alumina (20% silica). In this experiment, the ZSM-48 catalyst has a low conversion to hydrocarbons having a boiling point below the lubricating oil range (eg, about 650 to 750 ° F. (343 to 399 ° C.) and a heavy lubricant range (eg, about 900 to It is more selective for lubricating oil production, including heavy lubricant fraction production, which means lower conversion to heavy hydrocarbons into hydrocarbons having boiling points lower than 1000 ° F. + (482 to 538 ° C.). The conversion is calculated according to Equation 1 below using 700 ° F. + (371 ° C.) conversion as a specific example.

Formulations of ZSM-48 are known and are described, for example, in US Pat. Nos. 4,397,827, 4,585,747 and 5,075,269 and European Patent 0 142 317, which are incorporated herein by reference. Other hydrodewaxing catalysts useful in the practice of the present invention include any known catalyst that is mainly dewaxed by isomerization rather than decomposition or hydropyrolysis. Zeolites comprising 10 and 12 membered ring structures are particularly useful as dewaxing catalysts when combined with catalytic metal hydrogenation components. Illustratively, suitable zeolites and other catalyst components useful for hydrodewaxing are, for example, ZSM-23, ZSM-, known as rare earth ion exchanged ferrierite, mordenite, beta alumina, zeolite beta, theta one or TON. 35, ZSM-48, ZSM-57, ZSM-22, and silica alumino-phosphate and SSZ-32, known as SAPO (eg, SAPO-11, 31 and 41), are included. Alumina and amorphous silica alumina are also useful. However, in experiments using a hydrodewaxing catalyst comprising Pt on zeolite beta and a catalyst comprising Pt on amorphous silica alumina, a preferred 950 ° F. + (510 ° C. +) heavy lubricant fraction of about 50% by weight is in the fuel range. Is converted to a hydrocarbon having a boiling point of.

As used herein, the terms "hydrogen" and "hydrogen treatment gas" are synonymous and mean pure hydrogen or other gases or gases containing hydrogen in an amount sufficient for the desired reaction and preventing the reaction or adversely affecting the product. It may be a hydrogen containing process gas treated with a gas vapor containing (eg nitrogen and light hydrocarbons such as methane). The process gas vapor entering the reaction stage will preferably contain at least about 50 vol%, more preferably at least about 80 vol% hydrogen.

In an integrated process embodiment comprising a synthesis gas product, the synthesis gas is produced from natural gas and contacted with a cobalt Fischer-Tropsch catalyst to produce waxy hydrocarbons that are dewaxed by a multistage hydrodeswaxing process. It is not uncommon for natural gas to contain as much as 92+ mol% methane and primary residues C ₂₊ hydrocarbons, nitrogen and CO ₂ . Thus, it is an ideal and relatively clean fuel for syngas production. Methane has a 2: 1 H ₂ : C ratio and is ideal for producing synthetic gas having a molar ratio of H ₂ : CO of at least 2.1: 1 by a combination of partial oxidation and vapor reformation. This is the stoichiometric molar ratio used as the non-moving cobalt catalyst for hydrocarbon synthesis. Thus, natural gas is ideal for preparing synthetic gas having a molar ratio of H ₂ : C of the desired stoichiometric 2.1: 1 required when using cobalt Fischer-Tropsch hydrocarbon synthesis, preferably non-moving ones. Sulfur and heteroatom compounds are removed from natural gas and in some cases nitrogen and CO ₂ are also removed. The residual methane-rich gas is passed through a synthesis gas generator together with oxygen or air and steam. Oxygen is preferred for air as it does not introduce nitrogen into the synthesis gas generator (reactor). During the synthesis gas reaction, nitrogen forms the active inhibitors HCN and NH ₃ for the cobalt Fischer-Tropsch catalyst and therefore must be removed below 1 ppm. If nitrogen is not removed from the natural gas and / or used as an oxygen source before air is converted to the synthesis gas, HCN and NH ₃ must be removed from the synthesis gas before passing through one or more hydrocarbon synthesis reactors. In a synthesis gas generator, natural gas reacts with oxygen and / or steam to form a synthesis gas, which is then provided as a source for hydrocarbon synthesis. Known processes for syngas production include partial oxidation, catalytic vapor reforming, water gas shift reactions, and combinations thereof. These fixations include gas phase partial oxidation (GPOX), automatic temperature regeneration (ATR), fluidized bed synthesis gas generation (FBSG), partial oxidation (POX), catalytic partial oxidation (CPO) and vapor reformation. ATR and FBSG use oxygen and form synthesis gas by partial oxidation and catalytic vapor reformation. ATR and FBSG are preferred for preparing synthetic gas in the practice of the present invention. Observation of these processes and their relative advantages can be found, for example, in US Pat. No. 5,883,138. The invention will also be understood with reference to the following examples.

In the following examples, Fischer-Tropsch waxes are feed slurry Fischer that typically form a liquid hydrocarbon at the reaction conditions, the reaction in the presence of H ₂ and CO a titania supported cobalt rhenium catalyst obtained from Tropsch reactor ( i) a 430 ° F. + (232 ° C. +) waxy fraction or (ii) a 1000 ° F. + (538 ° C. +) fraction of the 430 ° F. + (232 ° C.) waxy fraction. The synthesis reactor is operated under conditions that produce more than 14 pounds (6.4 kg) of 700 ° F. + (371 ° C. +) hydrocarbons per 100 pounds (45.4 kg) of CO converted to hydrocarbons. The raw (untreated) wax was fed to the first stage of the following two and three steps. The intermediate separation cut point was 950 ° F. (510 ° C.). This means that only partially hydrowaxed 950 ° F. (510 ° C.) isomers recovered from the run step go through the second and third steps of the second and third steps of the two step process. The boiling point dispersions for the waxy feed used in the two and three run are shown in Table 1 below.

The hydrotreating gas used in all examples is pure hydrogen. ZSM-48 catalyst was used in all examples to hydrodewax the waxy feed. 0.6 wt% Pt is included as the hydrogenation component on the hydrogen form composition of the ZSM-48 zeolite and alumina binder. The hydrogen form of the ZSM-48 zeolite was prepared as described in US Pat. No. 5,075,269, which is incorporated herein by reference. The Pt component was added by injection, then cured and reduced using known procedures. Gas chromatography distillation (GCD) was carried out using the modified high temperature GCD method of ASTM D-5307. The column consists of a single capillary column with a thin liquid phase of less than 0.2 microns. The external standard used consists of a boiling point finder of 5 to 100 carbons. A temperature programmed injector was used prior to injection and the sample was slowly warmed up using hot water. Boiling ranges were determined using this method and T5 and T95 GCD results. The cloud point values were measured using ASTM D-5773 for Phase Tec Instruments under the lubricant procedure method. Pour point was measured according to ASTM D-5950 for ISL automatic pour point measurement. In the tables shown below, the cloud point and pour point are defined in ° C. Viscosity and viscosity were measured according to ASTM protocols D-445 and D-2270, respectively.

Comparative Example 1

The 1000 ° F. (538 ° C.) fraction of the 430 ° F. + (232 ° C. +) wax feed described above was hydrodewaxed by reacting with hydrogen in the presence of the ZSM-48 catalyst described above in a single step. Reaction conditions were 635 ° F. (336 ° C.), 250 psig (1724 kPa) and 2300SCF / B of H ₂ and LHSV of 1. These reaction conditions were used to achieve the desired coverage of 5 ° C. for 1000 ° F. + (538 ° C.) heavy lubricant base stock. The results of this run are shown in Table 1 below.

Example 1

In this example, according to the practice of the present invention, a 430 ° F. + (232 ° C. +) waxy feed is reacted with hydrogen through the ZSM-48 catalyst described above to give the same 1000 ° F. + with a cloud point of 5 ° C. in two steps. Hydrogen dewaxed with (538 ° C.) heavy lubricant base stock. The waxy feed was hydrodewaxed in the first step at a treatment rate of 2300SCF / B of H ₂ and LHSVd of 1 at 587 ° F. (308 ° C.), 250 psig (1724 kPa) of hydrogen. The first stage isomer is fractionated to separate the 700 [deg.] F .- (371 [deg.] C.) fraction and the 700 [deg.] F. + (371 [deg.] C.) feed conversion range to low boiling point material is determined and further fractionated to 950 [deg.] F. (510 [deg.] C.). +) The heavy oil fractions were separated and recovered. The 950 ° F. (510 ° C. +) heavy oil fraction was then hydrodewaxed in a second step at 614 ° F. (323 ° C.), 250 psig (1724 kPa) H ₂ at a treatment rate of 2500 SCF / B and 1 heavy oil LHSV. . The second stage isomer was fractionated to recover the final 1000 ° F. (538 ° C.) heavy lubricant base stock. The results of this run are also shown in Table 2 below.

These results clarify the advantages of the multi-step process that the amount of 1000 ° F. + (538 ° C.) heavy lubricant base stock produced using two steps at the same 5 ° C. destination point is significantly increased compared to using only a single step. Prove it. The use of a single step represents 39% by weight conversion to low boiling 700 ° F. (371 ° C.) hydrocarbons, whereas only 29% of the total conversion in the multistage process of the present invention. Since the lubricant stock cut point is typically about 700 ° F. (eg, about 700 ° F./371° C. + material), this means that brighter lubricant boiling hydrocarbons (750 to 950 ° F. (399 to 610 ° C.) boiling point range) It can be produced by the process. Similarly, the conversion of the total 1000 ° F. + (538 ° C.) fraction to a low boiling point 1000 ° F. (538 ° C.) hydrocarbon in a single step process is 61% compared to only 52% using the two step process of the present invention. . Thus, heavy lubricant based stocks are obtained in greater yields using the process of the present invention in the same subject cloud, with no loss in VI and a lower pour / cloud range.

Comparative Example 2

The reaction was carried out in the same manner as in Comparative Example 1 except that the reaction was carried out at a slightly lower temperature of 630 ° F. (322 ° C.) to obtain a 1000 ° F. + (538 ° C.) cloud point of 11 ° C. The results are shown in Table 3 below.

Example 2

The same procedure as in Example 1 was conducted except that the second stage reaction was carried out at a lower temperature of 610 ° F. (321 ° C.) to achieve a cloud point of 11 ° C. for the 1000 ° F. + (538 ° C.) product. These results are shown in Table 3 below compared to the results of Comparative Example 2 performing a single step.

As in the case of Example 1, the range of feed to convert to 700 ° F. (371 ° C.) and 1000 ° F. (538 ° C.) boiling point hydrocarbons using the multistage process of the present invention in this run is only a single step. It was very low compared to use.

Comparative Example 3

The reaction was performed in the same manner as in Comparative Example 1 except that the reaction was carried out at a higher temperature of 640 ° F. (338 ° C.) to obtain a 1000 ° F. + (538 ° C.) cloud point of −2 ° C. These results are shown in Table 4 below.

Example 3

The same procedure as in Example 1 was carried out except that the second stage reaction was carried out at a higher temperature of 620 ° F. (327 ° C.) to obtain a 1000 ° F. + (538 ° C.) heavy lubricant based stock product as the cloud point of Comparative Example 3. The same −2 ° C. cloud point was achieved for. These results are shown in Table 4 below compared to the results of Comparative Example 3 performing a single step.

As in the case of the above embodiments, the range of feed to convert to 700 ° F. (371 ° C.) and 1000 ° F. (538 ° C.) boiling point hydrocarbons using the multistage process of the present invention in this practice is only a single step. It was very low compared to use. The target cloud at 2 ° C. was over-performed to −4 ° C. using the two step process of the present invention to convert more to a low cloud point of −6 ° C. Despite the greater conversion using the two-step process, the conversion of both 700 ° F. + (371 ° C.) and 1000 ° F. + (538 ° C.) to low boiling hydrocarbons using the multistage process of the present invention is a single step. It is substantially lower than the process.

Example 4

In this example, the same 430 ° F. + (232 ° C. +) waxy feed and catalyst used in this example were used. In this example, however, the feed was hydrodewaxed to a 1000 ° F. + (538 ° C.) heavy fraction cloud at 5 ° C. in three steps according to the practice of the present invention. The wax feed was hydrodewaxed at a treatment rate of 587 ° F. (308 ° C.), 259 psig of hydrogen (1786 kPa), and 2300 SCF / B of H ₂ and waxy feed LHSV of 1. The process gas, process gas ratio and space velocity of the feed were the same in all three stages. The first step isomer was fractionated to separate and remove the 950 ° F. (610 ° C.) fraction while maintaining the 950 ° F. + (610 ° C.) fraction, followed by a second step. In the second step the temperature was 607 ° F. (321 ° C.). After removal of the 950 ° F. (610 ° C.) hydrocarbons from the second step isomer, the remaining additional partially dewaxed 950 ° F. (610 ° C. +) fraction is passed through a third step and 600 ° F. (316 ° C.) It was further hydrodewaxed at a temperature of. The third stage isomer was fractionated to separate and recover the 1000 ° F. + (538 ° C.) heavy lubricant base stock. The results of this run are shown together in Table 5 below for comparison with the results obtained from the single step hydroisomerization of Comparative Example 1.

The amount of the desired 1000 ° F. + (538 ° C.) heavy lubricant base stock product obtained using three steps was obtained using two steps (5 ° C. with the same 1000 ° F. (538 ° C.) heavy lubricant base stock being the same). Slightly higher than Example 1, which has a target point of). The amount of feed converted to 700 [deg.] F. (371 [deg.] C.)-Boiling hydrocarbons using three stages was about the same as using two stages, all of which were substantially lower than using only one stage. This is in addition to the heavy lubricant base stock obtained using the multistage hydrodeswaxing process of the present invention because the waxy feed is fed in a first stage containing substantially 950 ° F. (610 ° C.) boiling hydrocarbons. Prove that the yield is higher. The total amount of only 28% of the 430 ° F. + (232 ° C. +) feed hydrocarbons is 39% of 1000 ° F. + (538 ° C. +) hydrocarbons converted to 700 ° F. (371 ° C.) boiling point hydrocarbons using only one stage. Three steps are used to convert the hydrocarbons to 700 [deg.] F. (371 [deg.] C.) boiling point. In addition, the amount of beneficial 1000 ° F. + (538 ° C.) heavy lubricant based stocks lost by conversion to low boiling hydrocarbons were P261, 29 and 28% by weight in single, two and three step processes, respectively.

Example 5

In this example, the same 430 ° F. + (232 ° C. +) waxy feed and catalyst used in this example were used. However, in this example the feed was hydrodewaxed in three steps with a 1000 ° F. (538 ° C.) heavy fraction cloud of −3 ° C. 430 ° F. + (232 ° C. +) wax feed in step 1 at 587 ° F. (308 ° C.), 259 psig (1786 kPa) of hydrogen and 2300SCF / B of H ₂ and waxy feed LHSV of 1 at a treatment rate Mad. The process gas, process gas ratio and space velocity of the feed were the same in all three stages. The first step isomer was fractionated to separate and remove the 950 ° F. (610 ° C.) fraction while maintaining a partially dewaxed heavy 950 ° F. (610 ° C.) fraction, followed by a second step. In the second step the temperature was 607 ° F. (321 ° C.). After removal of 950 ° F. (610 ° C.) from the second phase isomer, the remaining additional partially dewaxed 950 ° F. (610 ° C. +) fraction was passed through the third step and subjected to 600 ° F. (316 ° C.). Hydrodewaxing at temperature. The third stage isomer was separated and fractionated to recover a 1000 ° F. + (538 ° C.) heavy lubricant base stock. The results of this run are shown in Table 6 below for comparison with the results obtained from the single step hydroisomerization of Comparative Example 1.

As can be seen in the case of Example 4, the desired 1000 ° F. + (obtained using three steps), as reflected by total or total conversion to hydrocarbons having a boiling point lower than 1000 ° F. + (538 ° C. +), was obtained. 538 ° C. +) The amount of heavy lubricant based stock product was much lower than that obtained using one step. The amount of feed converted to 700 ° F. (371 ° C.) boiling point hydrocarbons using three stages was substantially lower than using one stage.

Claims (27)

In the first hydrodewaxing step, the Fischer-Tropsch wax is hydrodewaxed to produce a partially dewaxed heavy lubricant fraction containing isomers, followed by one or more subsequent hydrodewaxing Heavy lubricant from Fischer-Tropsch wax, comprising hydrodewaxing the heavy lubricant fraction to form a heavy lubricant base stock while intermediately removing hydrocarbons having a boiling point lower than the heavy lubricant fraction in an intermediate step. A multistage process for preparing a substrate stock, wherein the hydrodewaxing is carried out in the presence of a hydrodewaxing catalyst which dewaxes by hydrogen and isomerization. The method of claim 1, Heavy lubricant based stocks have a lower cloud point and pour point than the heavy fractions in the wax. The method according to claim 1 or 2, The heavy lubricant fraction has an initial boiling point of at least 850 ° F. (454 ° C.). The method according to any one of claims 1 to 3, The heavy lubricant substrate stock has an initial boiling point of 850-1000 ° F. (454-538 ° C.). The method according to any one of claims 1 to 4, Wherein the partially dewaxed heavy lubricating oil fraction in one or more successive hydrodewaxing steps comprises less than 25% by weight of low boiling hydrocarbons. The method according to any one of claims 1 to 5, Heavy lubricant based stocks are hydrofinish and optionally declouded. The method according to any one of claims 1 to 6, A method wherein a heavy lubricant base stock is combined with one or more lubricant additives to form a lubricant. The method according to any one of claims 1 to 7, The heavy lubricant base stock has a terminal boiling point above 1050 ° F. (566 ° C.) and a cloud point below 75 ° F. (24 ° C.). The method according to any one of claims 1 to 8, Wherein the catalyst comprises a hydrogenation component, a solid acid component and a binder. The method of claim 9, Solid acid component ZSM-23, ZSM-35, ZSM-48, ZSM-57, ZSM-22, zeolite beta, mordenite, rare earth ion exchanged ferrierite, alumina, amorphous silica and mixtures thereof Method selected from. The method according to claim 9 or 10, And wherein the hydrogenation component comprises at least one Group VIII metal component. The method according to any one of claims 9 to 11, The binder may be zeolite, clay, silica, alumina, metal oxide, silica-alumina, silica-magnesia, silica-zirconia, silica-toria, silica-berilia, silica-titania, silica-alumina-toria, silica-alumina, zirconia , Silica-alumina-magnesia, silica-magnesia-zirconia and mixtures thereof. The method according to any one of claims 10 to 12, Wherein the zeolite component comprises ZSM-48 zeolite. The method according to any one of claims 11 to 13, The Group VIII metal is a precious metal. The method of claim 14, The precious metal is at least one of Pt and Pd. The method according to any one of claims 10 to 15, At least one step wherein the catalytic zeolite component comprises ZSM-48. (a) preparing a synthetic gas comprising a mixture of H ₂ and CO from natural gas; (b) contacting the synthesis gas with a cobalt Fischer-Tropsch hydrocarbon synthesis catalyst under reaction conditions effective to react the H ₂ and CO to form a waxy hydrocarbon comprising a hydrocarbon having a boiling point in the heavy lubricating oil range; (c) at least a portion of the waxy hydrocarbon is partially dehydrogenated, including the isomers by (i) hydrodewaxing in the presence of a hydrogen dewaxing catalyst and hydrogen in the first step of hydrowaxing; Preparing a waxed heavy lubricant fraction and a low boiling hydrocarbon, (ii) separating the partially dewaxed lubricant fraction and a low boiling hydrocarbon, and (iii) the separated heavy lubricant in one or more subsequent hydrodewaxing steps. A method of passing the separated heavy lubricating oil fraction through hydrodewaxing to form a heavy lubricant base stock by removing a hydrocarbon having a boiling point lower than the fraction in an intermediate step, thereby passing the zeolite component and precious metal hydrogenation. Where the hydrodewaxing catalyst comprising the component is used in one or more hydrodewaxing steps . The method of claim 17, wherein the waxy hydrocarbons formed in (b) are not hydroprocessed before passing through the hydrodewaxing enhancement plant. The method of claim 17 or 18, Heavy lubricant based stock having a lower cloud point and pour point than the heavy fraction in the wax. The method according to any one of claims 17 to 19, Heavy lubricant based stocks have an initial boiling point of at least 850 ° F. (454 ° C.). The method according to any one of claims 17 to 20, The precious metal comprises at least one of Pt and Pd. The method according to any one of claims 17 to 21, A method wherein the substrate stock is handmade and optionally declouded. The method according to any one of claims 17 to 22, The zeolite component is ZSM-23, ZSM-35, ZSM-48, ZSM-57, ZSM-22, silica-alumino phosphate, SSZ-32, zeolite beta, mordenite, rare earth ion exchanged ferrierite, alumina, secret A process selected from the group consisting of amorphous silica and mixtures thereof. The method of claim 23, The zeolite component is ZSM-48. The method according to any one of claims 17 to 24, A hydrodewaxing catalyst comprising a ZSM-48 zeolite component and a noble metal hydrogenation component of at least one of Pt and Pd is one or more consecutive ones used to further hydrodewaxify the first hydrowaxing step and the heavy lubricant fraction. The process used for the hydrodewaxing step. The method according to any one of claims 1 to 25, A method wherein a substrate stock is combined with one or more lubricant additives to form a lubricant. The method of claim 26, The heavy lubricant base stock has a terminal boiling point above 1050 ° F. (566 ° C.) and a cloud point below 75 ° F. (24 ° C.).