KR20160003203A - Process for preparing a heavy base oil - Google Patents

Abstract

The present invention provides a process for the production of a heavy base oil comprising the steps of:
(a) providing a hydrocarbon-based feedstock comprising at least 50% by weight of hydrocarbons boiling above 460 ° C, nitrogen in an amount in the range of 800-2500 ppmw, and sulfur in an amount ranging from 1.5 to 4.0% by weight;
(b) hydrotreating the hydrocarbon-based feedstock by means of a hydrotreating catalyst in the presence of a hydrogen-containing gas under hydrotreating conditions to produce a feedstock containing nitrogen in an amount ranging from 30 to 80 ppmw and sulfur in an amount ranging from 200 to 450 ppmw Obtaining a hydrotreated product;
(c) removing at least 50% of the N ¾ and ¾ S present in the hydrotreating product obtained in step (b);
(d) catalytically dewaxing at least some of the hydrotreated product obtained in step (c) by a dewaxing catalyst in the presence of a hydrogen-containing gas under catalytic dewaxing conditions to obtain a dewaxed product, Group metal hydride component, a dealuminated aluminosilicate zeolite crystalline and a low acid refractory oxide binder material (which is essentially free of alumina);
(e) hydrogenating and finishing at least some of the desorption products obtained in step (d) with a hydrogenation finishing catalyst in the presence of a hydrogen-containing gas under hydrogenation finishing conditions to obtain a heavy base oil; And
(f) recovering the heavy base oil.

Description

PROCESS FOR PREPARATION A HEAVY BASE OIL [0002]

The present invention relates to a process for the production of heavy base oils.

The main use of base oils is their use in lubricants such as motor oils to protect internal combustion engines in automobiles. Lubricants generally consist of a majority of base oil and various additives to achieve the desired properties.

Hard lubrication base oils are mainly used in automotive applications and heavy lubrication base oils are used in heavy duty applications such as marine engines and industrial processes.

The base oil used in the lubricant is first hydrotreated with vacuum gas oil distillate and / or deasphalted oil and then subjected to catalytic dewaxing and hydrofinishing at 370 ° C + fraction of the hydrotreated liquid or hydrotreated liquid product, . ≪ / RTI > In general, the noble metal scavenging catalyst is applied in the catalytic scavenging step. The noble metal scavenging catalyst is well known to be poisoned by organic nitrogen and organic sulfur compounds and therefore requires a severe hydrotreating process to sufficiently reduce the levels of organic nitrogen and organosulfur compounds in the hydrotreater at < RTI ID = 0.0 > 370 C & Step should be applied.

Generally, high processing severity in the hydrotreater improves the quality of the 370 ° C + hydrotreating product, which serves as the feedstock for the base oil plant. However, the high hydrogen treatment severity results in a lower yield of the 370 ° C + hydrotreated product, and the overall hydrotreated product becomes lighter (migrated due to the boiling point harsh hydrotreating) resulting in heavy lubrication of the hard lubrication base oil Which means that the ratio of base oil is substantially reduced.

Reduced heavy lube base oil yields are undesirable in times of high demand for heavy base oils.

It is therefore an object of the present invention to provide an upgraded process for hydrocarbonaceous feedstocks wherein a high yield of heavy lube base oil is obtained.

This objective is achieved when the hydrocarbonaceous feedstock is applied to an upgraded process involving a particular sequence of process steps.

Accordingly, the present invention relates to a process for the production of a heavy base oil comprising the steps of:

(a) providing a hydrocarbon-based feedstock comprising at least 50% by weight of hydrocarbons boiling above 460 ° C, nitrogen in an amount in the range of 800-2500 ppmw, and sulfur in an amount in the range of 1.2 to 4.0% by weight;

(b) hydrotreating the hydrocarbonaceous feedstock by means of a hydrotreating catalyst or a hydrotreating catalyst package in the presence of a hydrogen-containing gas under hydrotreating conditions to produce a feedstock having a nitrogen content in the range of 30-80 ppmw and a quantity in the range of 200-450 ppmw To obtain a sulfur-containing hydrotreating product;

(c) removing at least 50% of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b);

(d) catalytically dewaxing at least some of the hydrotreating product obtained in step (c) by a dewaxing catalyst in the presence of a hydrogen-containing gas under catalytic dewaxing conditions to obtain a dewaxed product, A metal hydride component, a dealuminated aluminosilicate zeolite crystalline and a low acid refractory oxide binder material (which is essentially free of alumina);

(e) hydrogenating and finishing at least some of the desorption products obtained in step (d) with a hydrogenation finishing catalyst in the presence of a hydrogen-containing gas under hydrogenation finishing conditions to obtain a heavy base oil; And

(f) recovering the heavy base oil.

According to the present invention, a high yield of heavy lubricating base oil can be obtained. The resulting heavy lubricating base oils include Group II and Group III lubricating base oils having a high proportion of heavy lubricating base oil to light lubricating base oil. The heavy lubricating base oil has a high viscosity which makes it very attractive for heavy duty applications.

The hydrocarbonaceous feedstock provided in step (a) preferably contains at least 50 wt.%, More preferably at least 65 wt.%, Of hydrocarbons boiling above 460 ° C. Suitably, the hydrocarbonaceous feedstock provided in step (a) has a 370 C + fraction with a viscosity at 100 C above 12 cSt, preferably 14 cSt.

The hydrocarbon-based feedstock contains nitrogen in an amount in the range of 800-2500 ppmw, preferably 1000-1500 ppmw, and sulfur in an amount in the range of 1.2-4.0 wt%, preferably 1.5-3.0 wt%.

The proportion of hydrocarbon fraction boiling in the range of 370-460 占 폚 and hydrocarbon fraction boiling in the range of 460-800 占 폚 in the hydrocarbon-based feedstock provided in step (a) is preferably less than 10.

Examples of hydrocarbon-based feedstocks for use in accordance with the present invention include straight-run gas oil, hydrocracking gas oil, thermal cracking gas oil, coker gas oil, vacuum gas oil, hard or heavy circulating oil, deasphalted oil DAO) or a combination of two or more thereof. The hydrocarbon feedstock may also be solvent extracted waxy raffinate. Some or more of the hydrocarbon-based feedstocks provided in step (a) may suitably be formulations obtained by combining one or more distillate fractions, preferably a vacuum distillate fraction, and deasphalted oil (DAO). The DAO that can be used is suitably obtained by deasphalting the residual hydrocarbon oil, preferably the vacuum residue. The deasphalting step may be performed in any conventional manner. A well-known and suitable deasphalting process is solvent deasphalting, which involves counter-current treatment of the residual hydrocarbon oil feed with extraction solvent. These extraction solvents are generally light hydrocarbon solvents containing paraffinic compounds of 3 to 8 carbon atoms, such as propane, butane, isobutane, pentane, isopentane, hexane and mixtures of two or more thereof. Preferred paraffinic hydrocarbons are those of hydrocarbons 3 to 5, with propane, butane, pentane and mixtures thereof being most preferred. Solvent deasphalting is typically carried out in a rotary disk contactor or in a plate column with the residual hydrocarbon oil feed entering the top or the bottom extract solvent. The light hydrocarbons present in the residual hydrocarbon oil are dissolved in the extraction solvent and withdrawn from the top of the apparatus. From this top-fraction, DAO is obtained after recovery of the extraction solvent. Asphaltenes that are insoluble in the extraction solvent are withdrawn from the bottom of the apparatus. The conditions under which deasphalting takes place are known in the art. Suitably the de-asphalt is carried out at a ratio of the total extraction solvent to the residual hydrocarbon oil of 1.5-8 wt / wt, a pressure of 1-50 bar and a temperature of 50-230 ° C.

Deasphalted oil can be obtained by deasphalting a residual fraction containing hydrocarbons having a boiling point of at least 460 DEG C, preferably a vacuum residual fraction.

In step (b), the hydrocarbonaceous feedstock is hydrotreated with a suitable hydrotreating catalyst or a hydrotreating catalyst package in the presence of a hydrogen-containing gas under hydrotreating conditions to provide an amount of nitrogen in the range of 30-80 ppmw, lt; RTI ID = 0.0 > ppmw < / RTI >

The hydrotreating catalyst or catalyst package used in the first reaction zone of step (a) is suitably a combination of a desulfurization catalyst or a desulfurization catalyst, which may be a demethanation catalyst or a combination of demetallation catalysts ). ≪ / RTI > The desulfurization catalyst may be a combination of hydrotreating catalysts to deliver a hydrotreated effluent having defined levels of nitrogen and sulfur or any hydrodesulfurization catalyst known in the art. Typically, such catalysts include compounds of the Group VIB metal of the periodic table as a hydrogenation component on a porous catalyst support, generally alumina or amorphous silica-alumina, and Group VIII metals of the periodic table. Well known examples of suitable combinations of hydrogenated compounds are cobalt-molybdenum, nickel-molybdenum, nickel-tungsten and nickel-cobalt-molybdenum. Hydrogenated desulfurization catalysts comprising nickel and / or compounds of cobalt and molybdenum as the hydrogenation compounds are preferred. The hydrotreated product obtained in step (b) contains nitrogen in an amount in the range of 30-80 ppmw and sulfur in an amount in the range of 200-450 ppmw, indicating that the hydrotreating in step (b) is not an extreme hydrotreating process it means. Hence, a hydrotreating catalyst or a combination of hydrotreating catalysts which is suitably not too active is used. Thus, preferably an alumina-based hydrotreating catalyst is used. Preferably, the catalyst is substantially free of cracking components. Particularly preferred are combinations of catalysts comprising molybdenum and cobalt and / or nickel supported on alumina without catalyst or zeolite cracking compound.

In step (b), a stacked bed arrangement in which two or more hydrotreating catalysts are loaded may also be used.

The temperature in the hydrotreating step is suitably in the range of 250-480 占 폚, preferably 280-450 占 폚, more preferably 350-420 占 폚.

Suitable hydrotreating pressures range from 30 to 250 bara. Preferably, the hydrotreating pressure is in the range of 110 to 180 bara, more preferably in the range of 120 to 170 bara.

The weight-setting rate is suitably in the range of 0.2-10 hr ^-1 , preferably 0.2-2.0 hr ^-1 , more preferably 0.2-1.0 hr ^-1 .

The exact hydrotreating conditions in step (a) will vary, in particular, of the catalyst used and the sulfur and nitrogen content of the hydrocarbon feedstock.

The ratio of the amount of nitrogen and the amount of sulfur (N / S) in the hydrotreating product obtained in step (b) is suitably in the range of 0.1 to 0.3, preferably in the range of 0.12 to 0.28.

In step (c), more than 50% of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b) are removed. Suitably, at least some of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b) are removed by stripping, preferably steam stripping. Suitably, the stripping is carried out at a temperature in the range of from 100 to 350 DEG C, preferably from 130 to 240 DEG C and at a pressure in the range from 1 to 50 bar, preferably from 1.5 to 10 bar. Preferably, at least 80%, more preferably at least 90% and most preferably at least 95% of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b) are hydrotreated in step (c) Is removed from the product. Preferably, the hydrocarbons boiling below 370 占 폚 in step (c) are also separated from the hydrotreating products obtained in step (b).

Preferably, the overall hydrotreated product obtained in step (b) is applied to step (c).

In step (d), at least some of the hydrotreating product obtained in step (c) is catalytically debinded by a dewaxing catalyst under a hydrogen-containing gas under catalytic dewaxing conditions to yield a dewaxing product, Group metal hydride component, a dealuminated aluminosilicate zeolite crystalline and a low acid refractory oxide binder.

Preferably, the entire hydrotreating product obtained in step (c) is applied to step (d).

Catalytic dewatering refers to a process of lowering the pour point of the lubricating base oil product by selectively converting a component of the oil feed that confers a high pour point into a product that does not impart a high pour point. The product giving a high pour point is a compound with a high melting point. These compounds appear as waxes. Wax compounds include, for example, high temperature melting normal paraffin, iso-paraffin and mono-cyclized compounds. The pour point is preferably lowered to 40 占 폚 or higher, more preferably 60 占 폚 or higher. In the process according to the present invention, the hydrocarbon-based feedstock will thus contain waxy molecules which confer undesirably high pour point. Small amounts of these compounds can greatly affect the pour point. The feedstock will suitably contain less than 2% to 80% of such waxy compounds.

In the catalytic dewaxing step according to the present invention, the hydrotreating feedstock is contacted under catalytic dewaxing conditions with a catalyst composition comprising a Group VIII metal hydride component, a dealuminated aluminosilicate zeolite crystalline and a low acid refractory oxide binder.

It has been found that this type of dewaxing catalyst is very stable over time, even in the presence of high sulfur content, and that nitrogen is present in the oil feed. Examples of such catalysts are described in WO-A-9641849.

The aluminosilicate zeolite crystals preferably have pores having a diameter in the range of 0.35 to 0.80 nm. This diameter represents the maximum pore diameter. As generally recognized, pores in molecular sieves are polygonal shaped channels with minimum and maximum pore diameters. For purposes of the present invention, the maximum pore diameter is a deterministic parameter because it determines the size of the waxy molecules that can enter the pores.

Examples of suitable aluminosilicate zeolites for use in the present invention include ferrierite, ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM- ZSM-57, SSZ-23, SSZ-24, SSZ-25, SSZ-26, SSZ-32, SSZ-33 and MCM-22 and mixtures of two or more thereof. Preferably, the zeolite component is ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 or ZSM-48.

Preferably, the zeolite component in the dewaxing catalyst is present in an amount ranging from 10 to 50% by weight based on the total weight of the dewaxing catalyst.

A preferred aluminosilicate zeolite is MFI-topology, for example ZSM-5.

Preferably, small crystals are used to achieve optimal catalytic activity. Preferably, a crystalline of less than 10 microns, more preferably less than 1 micron is used. The practical lower limit is suitably 0.1 micron.

The dewaxing catalyst also includes a low acid refractory oxide binder material that is essentially free of alumina. Examples are low acid refractory oxides such as silica, zirconia, titanium dioxide, germanium dioxide, boria and mixtures of two or more thereof. The most preferred binder is silica. The weight ratio of modified molecular sieve to binder is suitably within the range of 05/95 to 95/05.

Dealumination of the aluminosilicate zeolite yields a reduction in the number of alumina residues present in the zeolite and consequently a reduction in the molar percentage of alumina. The expressions used in this context "alumina moiety" are alumino-a part of the skeleton of the zeolite, that other oxide moieties, such as silica (SiO ₂₎ Al ₂ O are incorporated into the framework of the aluminosilicate zeolite with a covalent bond between the ₃ - unit. The molar percentage of alumina present in the aluminosilicate zeolite is the molar percentage of Al ₂ O ₃ to the total moles of the oxides constituting the aluminosilicate zeolite (before dealumination) or the modified molecular sieve (after dealumination) .

Preferably, the zeolite crystalline surface is optionally dealuminated. Selective surface dealumination results in a reduction in the number of surface acid sites in the zeolite crystalline, while not affecting the internal structure of the zeolite crystalline.

The dealumination can be obtained by methods known in the art. Particularly useful methods are those in which dealumination is selectively occurring, or whatever is claimed to occur selectively on the crystalline surface of the molecular sieve. An example of a dealumination process is described in the above-mentioned WO-A-9641849.

Preferably, the dealumination is carried out by a process wherein the zeolite is contacted with an aqueous solution of a fluorosilicate salt wherein the fluorosilicate salt is represented by the formula:

(A) _{2 / b} SiF ₆

Wherein A is a metallic or non-metallic cation other than H + having a valence of b. This treatment will also appear as an AHS treatment. Examples of cations 'b' are ^{alkylammonium, NH4 +, Mg ++, Li} +, Na +, K +, Ba ++, Cd ++, Cu +, Ca ++, Cs +, Fe ++, Co + ⁺ , Pb ⁺⁺ , Mn ⁺⁺ , Rb ⁺ , Ag ⁺ , Sr ⁺⁺ , Tl ⁺ and Zn ⁺⁺ . Preferably 'A' is an ammonium cation. The zeolite material may suitably be contacted with the fluorosilicate salt at a pH of from 3 to 7. The dealumination process is described, for example, in US-A-5157191. The dealumination process is indicated by AHS-treatment.

The dewaxing catalyst used according to the present invention is preferably prepared by first extruding an aluminosilicate zeolite and a binder, followed by dealumination, preferably by applying an extrudate to the AHS treatment described above. It has been found that the increased mechanical strength of the catalyst extrudate is obtained when prepared according to this step sequence.

The Group VIII metal of the periodic table is suitably added to the catalyst extrudate comprising the dealuminated aluminosilicate zeolite crystalline by well known techniques, such as ion-exchange techniques. Typical ion-exchange techniques require contacting the selected zeolite with the salt of the desired replacement cation. Chlorides, nitrides and sulfates are particularly preferred, although various salts may be used. Representative ion-exchange techniques are disclosed in various patents such as US-A-3140249, US-A-3140251 and US-A-3140253.

A dewaxing catalyst comprising a Group VIII metal hydride component in step (d) is used. Group VIII metal components include components based on both precious and non-precious metals. Particularly suitable Group VIII metal components are accordingly palladium, platinum, nickel and / or cobalt in the form of sulphide, oxide and / or element. The total amount of Group VIII metal in the periodic table is suitably calculated as an element and will not exceed 10% by weight, preferably from 0.1 to 5.0% by weight, more preferably from 0.2 to 3.0% by weight, based on the total weight of the support. Range. When both platinum and palladium are present, the weight ratio of platinum to palladium may vary within wide limits, but suitably ranges from 0.05 to 10, more suitably from 0.1 to 5. Catalysts comprising palladium, platinum and nickel as the hydrogenation component are preferred. The Group VIII metal hydrogenation component is preferably platinum or palladium, more preferably platinum.

The catalytic dewaxing conditions in step (d) of the process according to the invention are typical catalytic dewaxing conditions. Accordingly, the temperature is suitably in the range of 300-400 占 폚, preferably 320-390 占 폚, more preferably 330-380 占 폚. Suitable dewatering pressures range from 80-240 bara. Preferably, the dewatering pressure is in the range of 100-180 bara, more preferably 120-170 bara. The weight-setting rate in step (d) is suitably in the range of 0.4 to 7 hr ^-1 , preferably 0.5 to 2.5 hr ^-1 , more preferably 0.65 to 2.25 hr ^-1 .

Step (d) is carried out in the presence of hydrogen and hydrogen is suitably provided in the second reaction zone at a rate of 350 to 1500 Nl / kg of feed.

The wax product obtained in step (d) has a viscosity index (VI) which allows the production of a high VI lubricating base oil. The desorption product obtained in step (d) suitably contains sulfur in an amount of less than 350 ppmw, preferably less than 300 ppmw, which contains nitrogen in an amount of less than 80 ppmw, preferably less than 60 ppmw. The dewaxed product suitably has a viscosity at 100 DEG C in the range of 10 to 17 cSt, preferably 10 to 15 cSt.

In step (e), at least some of the desorption products obtained in step (d) are hydrogenated by a hydrogenation finishing catalyst in the presence of a hydrogen-containing gas under hydrogenation finishing conditions to obtain a heavy base oil.

Preferably, the overall dewatering product obtained in step (d) is applied to step (e).

Hydrofinishing is well known in the art and examples of suitable hydrogenation finishing steps are disclosed, for example, in US-A-5139647, WO-A-9201657 and WO-A-9201769. Generally, the hydrogenation finishing involves saturating some of the aromatic fractions still present in the debinding base oil by contacting the feed comprising the hydrocarbon feed, in this case the dewaxing base oil, with the hydrogenation catalyst under relatively moderate conditions . Suitable catalysts are applied for this purpose with noble metal-based catalysts, including Pt and / or Pd supported on an amorphous silica-alumina support. In an alternative embodiment of the present invention, a noble metal hydrogenation finishing catalyst, so-called nickel-molybdenum on a base metal hydrogenation finishing catalyst such as an alumina support, is used in the hydrotreating step of step (b).

The hydrogenation finishing conditions according to the present invention can be carried out at a working temperature in the range of 390 DEG C or lower, preferably 300 to 380 DEG C, more preferably 330 to 370 DEG C, a working pressure in the range of 80 to 200 bara, preferably 100 to 170 bara, And a weight construction rate in the range of 0.3-2.5 hr ^-1 , preferably 0.5-1.5 hr ^-1 .

The yield of the heavy base oil in step (e) is high when compared to known processes for the production of base oils in which the hydrocracking and catalytic dewetting steps are used. This high yield of the heavy base oil can be expressed as the ratio of the heavy base oil to the hard base oil obtained in step (e). A high yield of heavy base oil can be expressed, for example, as a ratio of 500 N base oil to 150 N base oil obtained in step (e). 500 N base oil is a heavy Group II base oil typically having a viscosity in the range of 10.0-12.9 cSt at 100 캜 while a 150 N base oil is a hard II group having a viscosity at 100 캜, typically in the range of 4.8-6.8 cSt Base oil. Suitably, the ratio of the 500N base oil to the 150N base oil obtained in step (e) is at least 1.0, preferably at least 1.5, more preferably at least 2.5, most preferably at least 3.0.

A high yield of heavy base oil is established by the use of a particular sequence of process steps (a) - (e) and the use of specific catalysts and / or catalyst combinations, and in particular in view of today's increasing demand for heavy base oils, Leading to major improvements over known processes for producing oils.

In step (f) the heavy base oil is recovered. The heavy base oil obtained in step (e) may be separated from other components of the effluent from the hydrogenation finishing process, including, for example, the hard base oil by conventional methods, such as distillation under atmospheric or reduced pressure. Among them, distillation under reduced pressure, such as vacuum flashing and vacuum distillation, is most suitably applied. The cut point (s) of the distillate fraction (s) is selected such that each of the recovered product distillates has the desired heavy base oil properties for its expected use.

The heavy base oil recovered in step (f) suitably contains sulfur in an amount less than 300 ppmw, preferably less than 200 ppmw, which contains nitrogen in an amount less than 80 ppmw, preferably less than 50 ppmw . Heavy base oils suitably have a viscosity at 100 DEG C in the range of 10-15 cSt, preferably 10-13 cSt.

The invention will be illustrated by the following non-limiting examples.

Basrah Light waxy distillate feedstock is provided in step (a).

Table 1: Main characteristics of feedstock

In step (b) the feedstock is hydrotreated.

Example 1 (according to the invention)

The feedstock described in Table 1 contains NiMo on a conventional alumina hydrotreating catalyst (in the case of this example, a Criterion catalyst < RTI ID = 0.0 > C-424 from the portfolio).

The working conditions and major results of the hydrotreating step are shown in Table 2 below.

Table 2: Preparation of hydrotreated effluent in step (b) of the present invention

Example 2 (Comparative Example)

The same feedstocks (Table 1) were prepared in a conventional manner at fairly low nitrogen and sulfur levels of less than 5 ppmw and less than 50 ppmw, respectively, to meet the typical requirements for the second stage noble metal isomerization-dewaxing and hydrogenation finishing catalyst according to the current practice Lt; / RTI > For this high activity a NiMo / Al ₂ O ₃ -type-II hydrotreating catalyst (DN-3100, for example from the Criterion catalyst portfolio) is required. The working conditions and major results of the hydrotreating step are shown in Table 3 below.

Table 3: Preparation of hydrotreated effluents in a conventional manner

Summary Table Step (b)

In step (c), H ₂ S and NH ₃ contaminants and hard products are stripped from the effluent obtained in Examples 1 and 2. Thereafter, the product obtained in step (d) in step (c) is applied to the dewetting step and the conventional dewetting step according to the invention.

Example 3 (According to the Invention)

The 370 ° C + fraction of Example 1 was catalytically tapped on a Shell commercial desoldering catalyst SLD-800, a base metal (Ni) catalyst specially developed for desiccation of heavily contaminated feedstock.

Working conditions and major results of the catalytic dewaxing step are shown in Table 4 below.

Table 4: Preparation of the catalytic dewaxing product according to the invention

Example 4 (Comparative Example)

The 370 < 0 > C + fraction of Example 2 was catalytically tanned on a noble metal (Pt) catalyst specially developed for the desalination of highly hydrogenated feedstocks for Shell commercial desoldering catalyst SLD-821, .

Working conditions and major results of the catalytic dewaxing step are shown in Table 5 below.

Table 5: Preparation of catalytic dewaxing product in a conventional manner

Summary Table Step (d)

In step (e), the debris product obtained in step (d) according to the present invention is hydrofinished.

Example 5 (according to the invention)

370 ℃ + fraction of Example 3 was stripped from any of the base, a base metal hydrogenation catalyst finishing (high activity NiMo / Al ₂ O ₃ - type of catalyst); Example 5a, or a noble metal hydrogenation finishing catalyst (e.g., Criterion LN-5); Is applied to the hydrogenation finishing step using Example 5b (known for its high hydrogenating ability and resistance to sulfur and nitrogen poisoning).

The working conditions and major results of the hydrogenation finishing step (e) are shown in Table 6 below.

Table 6: Preparation of the hydrofinishing product according to step (e) of the present invention

Example 6 (Comparative Example)

The 370 ° C + fraction of Control 4 stripped from any gas is applied to the hydrogenation finishing step (e) using a noble metal hydrogenation finishing catalyst (LN-5) from Criterion.

The working conditions and major results of the hydrogenation finishing step (e) are shown in Table 7 below.

Table 7: Preparation of hydrofinishing products in a conventional manner

From this point of view, it will be clear that the process of the present invention provides an improvement over conventional processes for producing heavy base oils.

Claims (15)

A process for producing a heavy base oil comprising the steps of:
(a) providing a hydrocarbon-based feedstock comprising at least 50% by weight of hydrocarbons boiling above 460 ° C, nitrogen in an amount in the range of 800-2500 ppmw, and sulfur in an amount ranging from 1.5 to 4.0% by weight;
(b) hydrotreating the hydrocarbon-based feedstock by means of a hydrotreating catalyst in the presence of a hydrogen-containing gas under hydrotreating conditions to produce a feedstock containing nitrogen in an amount ranging from 30 to 80 ppmw and sulfur in an amount ranging from 200 to 450 ppmw Obtaining a hydrotreated product;
(c) removing at least 50% of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b);
(d) catalytically dewaxing at least some of the hydrotreated product obtained in step (c) by a dewaxing catalyst in the presence of a hydrogen-containing gas under catalytic dewaxing conditions to obtain a dewaxed product, Group metal hydride component, a dealuminated aluminosilicate zeolite crystalline and a low acid refractory oxide binder material (which is essentially free of alumina);
(e) hydrogenating and finishing at least some of the desorption products obtained in step (d) with a hydrogenation finishing catalyst in the presence of a hydrogen-containing gas under hydrogenation finishing conditions to obtain a heavy base oil; And
(f) recovering the heavy base oil. The process of claim 1, wherein the hydrocarbon-based feedstock provided in step (a) contains greater than 65% by weight of hydrocarbons boiling above 460 ° C. 3. Process according to claim 1 or 2, wherein the hydrocarbon-based feedstock provided in step (a) contains at least 50% by weight of hydrocarbons having a viscosity at 100 DEG C of greater than 14 cSt. 4. The process according to any one of claims 1 to 3, wherein the ratio of the amount of nitrogen to the amount of sulfur (N / S) in the hydrotreating product obtained in step (b) is in the range of 0.1 to 0.3. The process according to any one of claims 1 to 4, wherein NH ₃ and H ₂ S are removed from the hydrotreating product obtained in step (b) by stripping in step (c). 6. The process according to any one of claims 1 to 5, wherein in step (c) at least 90% of the NH ₃ and H ₂ S present in the hydrotreating product obtained in step (b) are removed. 7. The process according to any one of claims 1 to 6, wherein in step (d) the zeolitic component in the dewaxing catalyst is present in an amount ranging from 10 to 50% by weight based on the total weight of the dewaxing catalyst. The process according to claim 7, wherein the zeolite component is ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 or ZSM-48. Any one of claims 1 to 8 according to any one of, wherein the step (b) hydrotreating conditions are a temperature in the range of 250-480 ℃, 30-250 bar pressure range 0.2-10 hr ^-1, and the range rate of the weight of the construction of the ; The dewatering conditions of step (d) include a temperature in the range of 350-460 ° C, a pressure in the range of 80-240 bar, and a rate of weight construction in the range of 0.4-7 hr ^-1 ; Wherein the hydrogenation finishing conditions in step (e) comprise a temperature in the range of 300-390 DEG C, a pressure in the range of 80 to 200 bar, and a weight construction rate in the range of 0.5-2.5 hr < ^-1 >. 10. The process according to any one of claims 1 to 9, wherein the hydrogenation finishing catalyst in step (e) is a noble metal-based hydrogenation finishing catalyst. 10. The process according to any one of claims 1 to 9, wherein in step (e) the hydrogenation finishing catalyst is a base metal hydrogenation finishing catalyst. Process according to any one of the preceding claims, wherein in step (c) the hydrocarbons boiling below 370 占 폚 are also separated from the hydrotreating product obtained in step (b). 13. The process according to any one of claims 1 to 12, wherein the entire hydrotreating product obtained in step (b) is applied to step (c). 14. The process according to any one of claims 1 to 13, wherein the entire hydrotreating product obtained in step (c) is applied to step (d). 15. The process according to any one of claims 1 to 14, wherein the total desalination product obtained in step (d) is applied to step (e).