CN102533329A - Method for producing base oil of lubricating oil by using Fischer-Tropsch synthesis wax - Google Patents

Abstract

A method for producing lubricating oil base oil from Fischer-Tropsch synthetic wax, comprising: a) contacting Fischer-Tropsch synthetic wax with a hydrofinishing catalyst in hydrofinishing reaction zone 1 to obtain a Fischer-Tropsch synthetic wax after hydrogenation olefin saturation and deoxygenation Tropsch synthesis wax; b) in a wax hydroconversion reaction zone A, the Fischer-Tropsch synthesis wax obtained in step a) is contacted with a hydroisomerization catalyst to obtain a wax conversion product oil with a reduced pour point; c) in a wax hydroconversion reaction zone A. A wax hydroconversion reaction zone B contacts the wax conversion product oil obtained in step b) with a hydroisomerization catalyst to obtain a wax conversion product oil with a further reduced pour point; d) in the hydrorefining reaction zone II contacting the wax-converted product oil obtained in step c) with a further lowered pour point with a hydrorefining catalyst to obtain a hydrorefined wax-converted product oil, e) converting the product oil obtained in step d) in a distillation zone Separated to obtain lubricating oil base oil.

Description

A kind of method of producing lubricating oil base oil by Fischer-Tropsch synthetic wax

technical field

The invention relates to a method for producing lubricating oil base oil by using Fischer-Tropsch synthetic wax as raw material.

Background technique

Using natural gas as raw material, wax with very low sulfur and nitrogen content can be obtained by Fischer-Tropsch synthesis. Through secondary processing, a variety of products with higher added value can be obtained from Fischer-Tropsch synthetic wax.

US 5834522 discloses a method for producing lubricating oil base oil using Fischer-Tropsch synthesis products as raw materials, which is characterized in that the hydro-treated Fischer-Tropsch synthesis products are hydroisomerized in the hydroisomerization reaction zone, and the isomerization reaction generates The oil is separated by distillation, after which the distillation bottoms are dewaxed to obtain oil and non-oil fractions. Wherein, the operating conditions of the hydroisomerization reaction zone are reaction temperature 200-450°C, pressure 2-25MPa, space velocity 0.1-10h ^-1 , the catalyst consists of an amorphous silica-alumina carrier and deposited thereon Composition of noble metals selected from Group VIII, the noble metal content is 0.05-100%, the catalyst does not contain zeolite molecular sieves and halogen elements, the carrier silicon oxide content is 5-45%, and the BET specific surface is 100-500m ² %, the silicon oxide is evenly distributed, the average pore diameter of the catalyst is 1-12nm, the pore volume of the pores larger than the average pore diameter 3nm and smaller than the average pore diameter 3nm is greater than 40%, and the dispersion coefficient of the noble metal is greater than 0.1.

US 5882505 discloses a method for producing lubricating oil base oil by converting Fischer-Tropsch synthetic wax with a boiling point greater than 370°C in a countercurrent reactor, including: reacting raw materials in a fixed bed under the conditions of hydrogen-containing gas and hydroisomerization reaction The hydroisomerization catalyst is contacted in the reactor; under the hydrodewaxing reaction conditions, the product after the hydroisomerization reaction is contacted with the hydrodewaxing catalyst in at least one fixed bed reactor, wherein, the The hydroisomerization reaction product flows countercurrently to the hydrogen-containing gas.

CN 1364188A discloses a preparation method of lubricating oil base oil, which method comprises the synthesis wax obtained by the Fischer-Tropsch process and not subjected to hydroisomerization treatment with at least hydrogenation component, dealuminated aluminosilicate The zeolite crystallites are contacted with a catalyst of a low acid refractory oxide binder material substantially free of alumina.

CN 1688674A A multi-step process for preparing heavy lubricating oil base stocks from Fischer-Tropsch waxes comprising hydrodewaxing the waxes in a first hydrodewaxing step to produce heavy lubricating oils comprising partial dewaxing The isomerization of an oil fraction, the heavy lube fraction is then hydrodewaxed in one or more successive hydrodewaxing steps, between which steps are removed the boiling oil below the heavy lube fraction hydrocarbons to form the heavy lube base stock, wherein the hydrodewaxing is carried out in the presence of hydrogen and an isomerization hydrodewaxing catalyst.

CN 1703488A A process for preparing fuel and lube oil bases, including heavy lube oil bases, from Fischer-Tropsch waxes containing hydrocarbon fractions boiling in the fuel and lube oil boiling ranges, comprising (i) adding said Wax hydrodewaxing to produce an isomerate comprising a hydrodewaxed fuel and a partially hydrodewaxed lubricating oil fraction, (ii) separating the two fractions, (iii) separating the partially hydrodewaxed lubricating oil The oil fraction is separated into a heavy fraction and a lower boiling fraction, and (iv) further hydrodewaxing the lower boiling fraction and the heavy fraction, respectively, to produce a lube oil base including a heavy lube oil base.

CN1703490A discloses a dual-function catalyst system for F-T wax hydroisomerization, adopting a series double-bed catalyst system composed of the first stage Pt/β catalyst and the second stage Pt/ZSM-48 catalyst to show high activity and selectivity.

The above-mentioned existing methods are mainly aimed at producing lubricating oil base oil, and Fischer-Tropsch synthetic wax can be processed to obtain high-quality lubricating oil base oil. However, since the heavy wax is more easily converted into small molecules by zeolite cracking reaction, the common problem in the existing method is that the yield of lubricating oil base oil is low.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new method for producing lubricating oil base oil from Fischer-Tropsch synthetic wax with a significantly improved yield of lubricating oil base oil in view of the defects of the prior art.

The method provided by the invention comprises: a) contacting Fischer-Tropsch synthetic wax with a hydrofinishing catalyst in hydrofinishing reaction zone I to obtain a Fischer-Tropsch synthetic wax after hydrogenation olefin saturation and deoxygenation; The hydroconversion reaction zone A contacts the Fischer-Tropsch synthesis wax obtained in step a) with a hydroisomerization catalyst to obtain a wax with a reduced pour point and converts it into oil; c) in a wax hydroconversion reaction zone B, the step b) The obtained wax-converted oil is contacted with a hydroisomerization catalyst to obtain a wax-converted oil with a further reduced pour point; d) The pour point obtained in step b) is further reduced in the hydrofinishing reaction zone II The converted wax generated oil is contacted with a hydrorefining catalyst to obtain a hydrorefined wax converted generated oil, and e) the generated oil obtained in step d) is separated in a distillation zone to obtain a lubricating oil base oil;

Wherein, the catalyst volume ratio of the wax hydroconversion reaction zone A to the wax hydroconversion reaction zone B is 0.2-5, the reaction temperature of the reaction zone A is higher than that of the reaction zone B, and the reaction temperature difference is 10-100°C.

Compared with the prior art, when the method provided by the invention is used to produce lubricating oil base oil with Fischer-Tropsch synthetic wax as raw material, the yield of lubricating oil base oil is obviously improved.

Description of drawings

Fig. 1 is a schematic flow chart of the method provided by the present invention.

Detailed ways

According to the method provided by the present invention, wherein, the catalyst volume ratio of the wax hydroconversion reaction zone A to the wax hydroconversion reaction zone B is 0.2-5, preferably 0.25-4, and the reaction temperature of the reaction zone A is higher than the reaction temperature Zone B, the reaction temperature difference is 10-100°C, preferably 10-50°C.

The wax hydroconversion reaction zone A and the wax hydroconversion reaction zone B are aimed at hydrogenating linear wax molecules into branched isoparaffins. Reaction conditions and hydroisomerization catalysts for the wax hydroconversion reaction zone are well known to those skilled in the art. The volume ratio of the catalyst in the aforementioned wax hydroconversion reaction zone A to wax hydroconversion reaction zone B is 0.2-5, preferably 0.25-4, the reaction temperature of reaction zone A is higher than that of reaction zone B, and the reaction temperature difference Under the condition of 10-100°C, preferably 10-50°C, the hydroisomerization catalyst and reaction conditions involved in the present invention can be catalysts and operating conditions commonly used in the art. Wherein, the catalysts used in the wax hydroconversion reaction zone A and the wax hydroconversion reaction zone B may be the same or different.

In a specific embodiment, the hydroisomerization catalyst comprises at least one mesoporous molecular sieve selected from the group VIII nickel, platinum and/or palladium metal components. The mesoporous molecular sieve is well known in the art, and can be selected from ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, SAPO-11 and SAPO-41 species or several. The content of the Group VIII metal is preferably 0.1-10% by weight, more preferably 0.1-5% by weight, calculated as metal and based on the catalyst. For example, CN1228357A discloses a catalyst containing molecular sieves and precious metals, CN1448484A discloses a dewaxing catalyst, CN1803998A discloses a dewaxing catalyst, and CN1382526A discloses a hydrodewaxing catalyst, etc., all of which have good wax hydroisomerization Reaction performance, all can be used in the present invention as hydroisomerization catalyst. In particular, the hydrodewaxing catalyst disclosed in CN1382526A has better wax conversion activity and selectivity to lubricating base oil when used in the present invention, so it is particularly suitable for the present invention.

In a preferred embodiment, the reaction conditions of the wax hydroconversion reaction zone A include: pressure 1-20MPa, more preferably 4-18MPa, temperature 260-400°C, more preferably 310-380°C, volume space velocity 0.3- 4h ^-1 , more preferably 0.5-2h ^-1 , hydrogen-oil volume ratio 100-3000, more preferably 200-1000; the reaction conditions in the wax hydrogenation conversion reaction zone B include: pressure 1-20MPa, more preferably 4-18MPa , temperature 250-390° ^{C, more preferably 300-370°C, volume space velocity 0.3-4h -1 ,} more preferably 0.6-2h ^-1 , hydrogen-oil volume ratio 100-3000, more preferably 200-1000.

According to the method provided by the present invention, the hydrofinishing reaction zone I is mainly aimed at removing olefins and oxygen in the Fischer-Tropsch synthesis wax by hydrogenation. The hydrosaturation and hydrodeoxygenation reactions of olefins are well known to those skilled in the art, and the hydrofinishing catalysts and reaction conditions involved may be catalysts and operating conditions commonly used in the art.

In a specific embodiment, the hydrofinishing catalyst used in the hydrofinishing reaction zone I consists of a heat-resistant inorganic oxide carrier (with or without molecular sieve) and cobalt and/or nickel supported on the carrier, Molybdenum and/or tungsten with or without one or more additives selected from fluorine, phosphorus or boron. Wherein, the content of each component is a conventional content, based on oxides and catalysts, preferably containing 1-8% by weight of cobalt and/or nickel, 10-35% by weight of molybdenum and/or tungsten, and In terms of elements, 0-6% by weight of one or more auxiliary components in fluorine, phosphorus and boron, and a balanced amount of carrier. For example, CN1105053A discloses a hydrofinishing catalyst, CN1136069A discloses a hydrofinishing catalyst, CN1169336A discloses a hydrofinishing catalyst, CN1803283A discloses a hydrotreating catalyst, etc., all of which have good hydrogenation olefin saturation and hydrogenation deoxygenation activity, can be used in the present invention as a hydrorefining catalyst. In particular, when the hydrorefining catalyst disclosed in CN1169336A is used in the present invention, it can achieve very good saturation of hydrogenated olefins and hydrodeoxygenation at a relatively low hydrogenation reaction temperature, so it is particularly suitable for use in the present invention.

The hydrofinishing catalyst used in the hydrofinishing reaction zone I is presulfurized with sulfur, hydrogen sulfide or sulfur-containing raw materials at a temperature of 140-370°C, preferably in the presence of hydrogen, before use. It can be vulcanized outside or in situ to convert it into sulfide type.

In a preferred embodiment, the reaction conditions of the hydrofining reaction zone I are: hydrogen partial pressure 1-25MPa, more preferably 3-20MPa, reaction temperature 150-400°C, more preferably 180-350°C, volume empty The rate is 0.3-8h ^-1 , more preferably 0.5-5h ^-1 , and the hydrogen-to-oil ratio is 100-3000 (v/v), more preferably 200-1500 (v/v).

The hydrofinishing reaction zone II can be the same or different for the purpose of hydrodewaxing conversion of olefin saturation in the resulting oil and decolorization of the resulting oil or heavy wax hydrodecolorization. The hydrosaturation and hydrodecolorization reactions of olefins in oil products are well known to those skilled in the art. Wherein, the hydrorefining catalyst and reaction conditions involved may be catalysts and operating conditions commonly used in the art.

In a specific embodiment, the hydrofinishing catalyst used in the hydrofinishing reaction zone II contains a carrier and at least one metal group selected from Group VIII of nickel, platinum and/or palladium supported on the carrier point. The carrier may be selected from alumina, silica, titania, magnesia, silica-alumina, alumina-magnesia, silica-magnesia, silica-zirconia, silica-thoria, silica - beryllia, silica-titania, silica-zirconia, titania-zirconia, silica-alumina-thoria, silica-alumina-titania, silica-alumina-magnesia, silica-alumina-magnesia, One or more of silicon-alumina-zirconia, natural zeolite, and clay. The content of the Group VIII metal is preferably 0.1-10% by weight, more preferably 0.1-5% by weight, calculated as metal and based on the catalyst. For example, CN1510112A discloses a metal-type hydrogenation catalyst, CN1171429A discloses an aromatic hydrocarbon hydrogenation catalyst, and CN1245204 discloses a bimetallic hydrogenation catalyst, etc., all of which have good hydrofinishing properties and can be used as hydrofinishing reaction zones The hydrorefining catalyst employed in II is used in the present invention. In particular, a metal-type hydrogenation catalyst disclosed in CN1510112A has better hydrofining performance when used in the present invention, so it is particularly suitable for use in the present invention.

In a preferred embodiment, the reaction conditions of the hydrofining reaction zone II are: hydrogen partial pressure 1-20MPa, more preferably 4-18MPa, reaction temperature 150-380°C, more preferably 180-350°C, volume empty The rate is 0.3-3h ^-1 , more preferably 0.5-1.5h ^-1 , and the hydrogen-to-oil ratio is 100-3000 (v/v), more preferably 200-1000 (v/v).

The hydrofinishing catalyst used in the hydrofinishing reaction zone II is preferably reduced in the presence of hydrogen at 150-500° C. to convert it into a reduced state before use. This reduction method is a conventional method, and the reduction can be performed outside the reactor or in situ in the reactor.

According to the method provided by the present invention, the distillation method in the distillation zone is well known in the art, and usually may include one or more operating units of flash evaporation, atmospheric distillation and vacuum distillation as required to complete the desired separation.

By adopting the method provided by the invention to process Fischer-Tropsch synthetic wax, while obtaining lubricating oil base oil, the light component therein can be recycled as high-quality solvent oil with high added value. The Fischer-Tropsch synthetic wax can be derived from wax obtained by Fischer-Tropsch synthesis using natural gas as a raw material, or wax obtained by Fischer-Tropsch synthesis using coal as a raw material.

The following examples will further illustrate the present invention.

Hydrotreating catalyst, dewaxing catalyst and hydrogenation catalyst used in the embodiment of the present invention and preparation method thereof are as follows:

1. Catalyst a used in hydrotreating zone I

The hydrorefining catalyst a used in the embodiment of the present invention is prepared according to example 6 in CN1169336A with fluorine as auxiliary agent, nickel-tungsten is the catalyst that the active component is loaded on the alumina carrier, wherein the total amount of catalyst is As a standard, the content of nickel is 2.3% by weight in terms of oxides, the content of tungsten is 22% by weight, the content of fluorine is 4% by weight in terms of elements, and the balance is alumina.

2. The catalyst used in wax hydroconversion reaction zone A and wax hydroconversion reaction zone B is the same catalyst b

Catalyst b is the catalyst prepared according to example 6 in CN1382526A with platinum as the active component loaded on the SAPO-11 molecular sieve/alumina carrier, wherein based on the catalyst total amount, the content of platinum metal is 0.3% by weight, and all the other are Carrier, based on the carrier, the content of SAPO-11 molecular sieve in the carrier is 75% by weight, and the rest is alumina.

3. Catalyst c used in hydrotreating reaction zone II

The hydrogenation catalyst c used in the examples of the present invention was prepared according to Example 11 in CN1510112A, wherein the content of platinum metal was 0.22% by weight, and the content of palladium metal was 0.43% by weight.

Example 1

This example takes a kind of Fischer-Tropsch synthetic wax as raw material, and its properties are shown in Table 1.

Process this raw material according to Fig. 1 process flow. The catalysts are as follows: Catalyst a is used in hydrorefining zone I, catalyst b is used in both wax hydroconversion reaction zone A and wax hydroconversion reaction zone, the catalyst loading ratio of A zone and B zone is 3:2, and the hydrorefining zone Catalyst c is used in Zone II, and the operating conditions are shown in Table 2.

See Table 3 for the material balance after separation in the distillation zone.

The properties of lubricating oil base oil are shown in Table 4.

Table 1

             

Item F-T Synthetic Wax

             

Density (20℃)/g.·cm ^-3 0.8055

Freezing point/°C 95 (melting point)

Sulfur content/μg·g ^-1 <5

Nitrogen content/μg·g ^-1 <5

Oxygen content/%(w) 0.35

Distillation range/°C D-1160

Initial boiling point 255

10% 398

30% 464

50% 520

70% 578

90% 656

95% 677

Carbon number distribution/%

C13-C19 2.405

C20-C29 19.742

C30-C39 28.881

C40-C49 19.928

C50-C59 11.595

C60-C69 7.782

C70-C79 6.186

C79-C87 3.486

             

Table 2

table 3

Hydrogen consumption, % 0.5 output, % gas 5.5 ＜165 20.8 165-370℃ 31.2 ＞370℃(lubricating oil fraction) 43

Table 4

               

product nature

               

Yield/% 43

Kinematic viscosity/mm ² ·s ^-1

100℃ 5.75

40°C 28.50

Viscosity Index 149

Pour point/℃ -28

Sulfur/μg·g ^-1 <5

Nitrogen/μg·g ^-1 <1

Aromatics content/w% ＜1

               

Comparative example 1

Process Fischer-Tropsch synthetic wax as raw material according to the technological process shown in Figure 1, and its properties are shown in Table 1, except that the wax hydroconversion reaction zone is a single reaction zone. The catalysts are as follows: Catalyst a is used in the hydrofinishing zone I, catalyst b is used in the wax hydroconversion reaction zone, and catalyst c is used in the hydrofinishing zone II. The operating conditions are shown in Table 5.

The material balance after separation in the distillation zone is shown in Table 6.

The properties of lubricating oil base oil are shown in Table 7.

table 5

Table 6

Hydrogen consumption, % 0.6 output, % gas 6.7 ＜165℃ 23.1 165-370℃ 46.8 ＞370℃ twenty four

Table 7

Comparative example 2

Process Fischer-Tropsch synthetic wax as raw material according to the technological process shown in Figure 1, and its properties are shown in Table 1, except that the wax hydroconversion reaction zone is a single reaction zone. The catalysts are as follows: Catalyst a is used in the hydrofinishing zone I, catalyst b is used in the wax hydroconversion reaction zone, and catalyst c is used in the hydrofining zone II. The operating conditions are shown in Table 8.

See Table 9 for the material balance after separation in the distillation zone.

The properties of lubricating oil base oil are shown in Table 10.

Table 8

Table 9

Hydrogen consumption, % 0.4 output, % gas 4.8 ＜165℃ 15.2 165-370℃ 26.4 ＞370℃ 54

Table 10

Claims (10)

1. method of producing lubricant base by the Fischer-Tropsch synthetic wax, comprising: a) I contacts the Fischer-Tropsch synthetic wax with Hydrobon catalyst in the hydrofining reaction district, obtains that a kind of hydrogenation alkene is saturated, the Fischer-Tropsch synthetic wax after the deoxidation; B) at a wax hydroconversion reactions district A Fischer-Tropsch synthetic wax that step a) obtains is contacted with hydroisomerisation catalysts, obtain a kind of depression of pour point wax transform to generate oil; C) wax that at a wax hydroconversion reactions district B step b) is obtained transforms and generates oil and contact with hydroisomerisation catalysts, and obtaining wax that a kind of pour point further reduced, to transform generation oily; D) wax that II obtains step c) in the hydrofining reaction district pour point has further reduced transforms and generates oil and contact with Hydrobon catalyst; Obtaining wax after a kind of unifining transforms and generates oil; E) a distillation zone that the generation that step d) obtains is separating of oil, obtain lubricant base;

Wherein, wax hydroconversion reactions district A is 0.2-5 with the catalyst volume ratio of wax hydroconversion reactions district B, and the temperature of reaction of reaction zone A is higher than reaction zone B, and the reaction temperature difference is 10-100 ℃.

2. method according to claim 1 is characterized in that, said wax hydroconversion reactions district A is 0.25-4 with the catalyst volume ratio of wax hydroconversion reactions district B, and the reaction temperature difference of said reaction zone A and reaction zone B is 10-50 ℃.

3. method according to claim 1; It is characterized in that; Said hydroisomerisation catalysts contains at least a mesoporous molecular sieve that is selected from nickel, platinum and/or the metallic palladium component of group VIII; In metal and with the catalyzer is benchmark, and the content of said group VIII metal is 0.1-10 weight %.

4. method according to claim 3; It is characterized in that; Said mesoporous molecular sieve is selected from one or more among ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, SAPO-11 and the SAPO-41; In metal and with the catalyzer is benchmark, and the content of said group VIII metal is 0.1-5 weight %.

5. method according to claim 1 is characterized in that, the reaction conditions of said wax hydroconversion reactions district A comprises: pressure 1-20MPa, temperature 260-400 ℃, volume space velocity 0.3-4h ^-1, hydrogen to oil volume ratio 100-3000; The reaction conditions of said wax hydroconversion reactions district B comprises: pressure 1-20MPa, temperature 250-390 ℃, volume space velocity 0.3-4h ^-1, hydrogen to oil volume ratio 100-3000.

6. according to the described method in claim/5, it is characterized in that the reaction conditions of said wax hydroconversion reactions district A comprises: pressure 4-18MPa, temperature 310-380 ℃, volume space velocity 0.5-2h, hydrogen to oil volume ratio 200-1000; The reaction conditions of said wax hydroconversion reactions district B comprises: pressure 4-18MPa, temperature 300-370 ℃, volume space velocity 0.6-2h ^-1, hydrogen to oil volume ratio 200-1000.

7. method according to claim 1 is characterized in that, the reaction conditions of said hydrofining reaction district I comprises: hydrogen dividing potential drop 1-25MPa, temperature of reaction is 150-400 ℃, volume space velocity 0.3-8h ^-1, hydrogen to oil volume ratio is 100-3000.

8. method according to claim 7 is characterized in that, the reaction conditions of said hydrofining reaction district I comprises: hydrogen dividing potential drop 3-20MPa, temperature of reaction is 180-350 ℃, volume space velocity 0.5-5h ^-1, hydrogen to oil volume ratio is 200-1500.

9. method according to claim 1 is characterized in that, the reaction conditions of said hydrofining reaction district II comprises: hydrogen dividing potential drop 1-20MPa, temperature of reaction is 150-380 ℃, volume space velocity 0.3-3h ^-1, hydrogen to oil volume ratio is 100-3000.

10. method according to claim 9 is characterized in that, the reaction conditions of said hydrofining reaction district II comprises: hydrogen dividing potential drop 4-18MPa, temperature of reaction is 180-350 ℃, volume space velocity 0.5-1.5h ^-1, hydrogen to oil volume ratio is 200-1000.

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