RU2258733C2 - Lubrication oil base production process - Google Patents

Abstract

FIELD: petrochemical processes.

SUBSTANCE: preliminarily hydrofined high-paraffin feedstock is subjected to isomerization and dewaxing, which are carried out in presence of catalysts modified with group VIII metals. In the isomerization stage, catalyst is based on aluminum oxyfluoride, silica-alumino phosphate, or zeolite, modified with group VIII metals, or yet inorganic phosphorus compound. In the dewaxing stage, catalyst is based on silica-alumino phosphate or zeolite modified with inorganic phosphorus compound. Catalysts used in isomerization and/or dewaxing stages may be modified with organic nitrogen compounds. Feedstock for the process can be paraffin slack wax and paraffins, including synthetic ones. Isomerization and dewaxing process are carried out at 320-415°C, partial hydrogen pressure 3.0-7.0 MPa, feedstock volumetric feeding rate 0.5-1.5 h^-1, and consumption of hydrogen 500-2000 nm³ per 1 m³ feedstock.

EFFECT: increased yield of lubrication oil fraction and improved quality of oil (pour point and viscosity index).

6 cl, 1 tbl, 12 ex

Description

The invention relates to petrochemistry, and in particular to a method for producing a base of lubricating oils by catalytic conversion of a paraffin-containing hydrocarbon feed in the presence of hydrogen.

Known methods for producing base oils by hydroprocessing of high boiling oil fractions (200-500 ° C) and hydrocarbon raw materials containing normal structure paraffins C ₁₀ -C ₄₀ . A common feature of these methods is the presence in the process of hydroprocessing of raw materials of the stage of normal paraffin isomerization, which is carried out at a temperature of 250-350 ° C, a mass feed rate of 1.5-10 h ^-1 , a hydrogen pressure of 1.0-8.0 MPa, the molar ratio of H ₂ / hydrocarbons 1-20, on bifunctional zeolite-containing catalysts. The following structural types are used as zeolites and elemental silicates: ZSM-5, 11, 12, 20, 23 38, mordenite, beta, L, SAPO-5, 11, modified with metals of groups VI, VII, VIII of the Periodic system, usually platinum, palladium , and also subjected to dealumination in order to change the acid characteristics.

(U.S. Patent Nos. 5643440, CL 208-58, 1977; No. 5135638, CL 208-27, 1992; No. 5146022, CL 585-12, 1992; No. 4859311, CL 208-89, 1989; No. 4710485, CL 502-213.1982).

The disadvantage of these methods is the production of lubricating oils either of insufficient quality or with a low yield, as well as the cost of the process using selective dewaxing.

Known methods for the hydrotreatment of petroleum fractions, in particular gacha and paraffin-containing types of raw materials, in the presence of zeolite and elemental silicate isomerization catalysts, in order to expand the range of raw materials to obtain base oils. The catalysts are modified with metals of groups II, VI and VIII of the Periodic system, for example, simultaneously with chromium and calcium, or one chromium, as well as palladium. The following structural types are used as zeolites and elemental silicates: ZSM-12, beta, L, SAPO-5, 11.31.

(Pat. RF №2148611, class C 10 G 49/08, 2000; Pat. RF No. 2152426, class C 10 G 47/16, 2000).

The disadvantage of these methods is that the one-stage process of hydroisomerization of gachey does not allow to obtain high index lubricating oils with low pour points.

There is also known a method for the catalytic isodeparaffinization of high paraffin concentrates in the presence of a catalyst system consisting of Pt / SAPO-11 and Pt / ZSM-22. Raw materials are paraffin concentrates with a melting point of 38 ° C, 46 ° C. In the examples, the process is carried out at temperatures of 349 ° C, 357 ° C, a mass feed rate of 1 hour ^-1 , a pressure of 15.0 MPa. This gives a product with a pour point of from -9 ° C to -20 ° C and viscosity indices of 120-138, depending on the type of feed.

(US Pat. No. 5,149,421, cl. 208-114, 1992).

The disadvantage of this method is that the implementation of the process at high pressure significantly increases its cost and makes it difficult to implement at enterprises in the industry.

Closest to the proposed one is a method for producing a base of lubricating oils from high-paraffin raw materials that have previously gone through a hydrotreatment stage, in particular from gachas and synthetic paraffins, comprising contacting the raw materials with a system of catalysts for the stages of isomerization and dewaxing. The catalyst of the first stage - isomerization is an amorphous aluminosilicate with a certain pore size, modified with hydrogenating metals of groups VI B and VIII of the Periodic System: Ni, Co, Mo, W, Pt, Pd. The catalysts of the second stage - dewaxing are zeolites and elemental silicates of the following structural types: ZSM-5, 8, 11, 23, 35, SAPO-11, 31,41.

Isomerization is carried out at a temperature of 325-415 ° C, a pressure of 3.0-15 MPa, a bulk density of the feed rate of 0.5-1.2 kg / l / h, a hydrogen flow rate of 1500 nl / h, while the output of the base lubricating oil ranges from 33 to 49.5% wt. depending on the composition of the catalyst.

Catalytic dewaxing is carried out at a temperature of 200-500 ° C, a hydrogen pressure of 0.5-10 MPa, a feed rate of 0.1-5 kg / l / h and a ratio of hydrogen to feed of 100-2500 l / kg.

It should be noted that along with catalytic dewaxing in the known method used selective dewaxing with solvents.

(Pat. RF №2116332, class C 10 G 47 / 12,1998).

The disadvantage of the method described in the prototype is the inability to obtain a lubricating oil of the required quality with high viscosity indices and low pour points, while obtaining a high yield of the target product, as well as the cost of the process using selective dewaxing.

The objective of the invention is to develop a method for producing a base of lubricating oil, which allows to increase the yield of the target oil fraction while improving quality indicators - viscosity index and pour point, and the possibility of implementing the process at the enterprises of the industry.

The problem is solved by the proposed method for producing the base of lubricating oils from high-paraffin raw materials, previously passed the hydrotreatment stage, including the stages of isomerization and dewaxing, carried out at elevated temperatures and excess pressure of hydrogen, in the presence of catalysts modified with metals of group VIII of the Periodic system. The method is characterized in that, at the isomerization stage, a catalyst based on fluorinated alumina, or silicoaluminophosphate, or zeolite modified with Group II metals of the Periodic System, or an inorganic phosphorus compound is used; at the stage of dewaxing, a catalyst based on silicoaluminophosphate or zeolite modified with an inorganic phosphorus compound is used.

Moreover, the zeolite catalyst used in the isomerization stage is modified with a metal of group II of the Periodic system in an amount of 0.3-5% wt. in terms of oxides, or inorganic phosphorus in an amount of 3-10% wt. in terms of P ₂ About ₅ .

The catalyst used in the dewaxing step is modified with an inorganic phosphorus compound in an amount of 3-10% by weight. in terms of P ₂ O ₅ .

Used at the stages of isomerization and dewaxing, or at one of them, the catalysts can be modified with organic nitrogen compounds, in an amount of 0.5-7% wt. in terms of nitrogen.

Paraffin waxes and paraffins, including synthetic ones, are used as raw materials, the isomerization and dewaxing stages are carried out at a temperature of 320-415 ° C, a partial pressure of hydrogen of 3.0-7.0 MPa, with a bulk feed rate of 0.5-1, 5 hour ^-1 , the flow rate of hydrogen to raw materials 500-2000 nm ³ / m ³ .

The proposed method for producing a base of lubricating oils from pump and synthetic paraffins allows increasing the yield of the target oil fraction with high viscosity indices and low pour points due to the combination of the stages of isomerization and dewaxing, the use of certain structural types of zeolites and elemental silicates as the basis of the catalysts and the modification of the catalysts of these stages inorganic phosphorus compounds, metals of group II of the Periodic system and organic nitrogen compounds.

The use of modified catalysts leads to an increase in the selectivity of isomerization and dewaxing processes by blocking the surface acid centers of medium-pore zeolites with pore sizes of 5-6 U and aluminophosphates, or by reducing the strength of acid centers and partial blocking of channels of wide-porous zeolites with pore sizes of 6-8 E.

It should be noted that at the isomerization stage, fluorinated alumina, crystalline silicoaluminophosphates with a structure of the SAPO-11, 31 type, zeolites of the beta, ZSM-12 type, both with and without a binder, can be used as the catalyst base.

Crystalline silicoaluminophosphates with the SAPO-11.31 structure, or zeolites with the ZSM-5, 11, 22 structure, with or without a binder, can be used as the basis for the catalysts for the dewaxing stage.

As a binder, the catalysts of both stages can be used alumina, aluminosilicates, oxides of titanium, zirconium, amorphous aluminophosphates or mixtures thereof in an amount of 5-95% wt.

As metals of group II of the Periodic system can be used calcium, strontium, barium, mainly barium, strontium.

Inorganic modifiers - compounds of phosphorus and metals of group II of the Periodic system are introduced into the composition of the catalyst in the form of phosphoric acids, ammonium phosphates and soluble metal salts by the methods of coextrusion, impregnation or ion exchange

Organic modifiers - nitrogen compounds (amines, nitrogenous bases) are applied to the catalysts as a result of pre-treatment or introduced with the first portions of raw materials.

The catalysts of the stages of isomerization and dewaxing are modified with metals of group VIII of the Periodic system, in particular Pt and Pd in an amount of 0.1-2% wt.

Hydrogenating metals are introduced into the catalyst from solutions of their compounds by coextrusion, impregnation or ion exchange

The proposed method can be carried out both in one reactor with the coincidence of the optimal technological parameters of the stages of isomerization and dewaxing (while the catalysts of these stages are located in layers), and in two reactors in series, if these parameters differ.

The feed is contacted with the catalysts in the presence of pure hydrogen or a hydrogen-containing gas containing more than 50% vol. hydrogen.

The applicability of the invention can be illustrated by the following examples.

The process conditions and results are presented in table 1.

Example 1

The proposed method is carried out in two successive reactors. Paraffins with a melting point of + 56 ° C are used as raw materials. The feed is fed to a flow-type isomerization reactor, where it is contacted with a catalyst comprising fluorinated alumina modified with platinum in an amount of 0.5% wt.

Isomerization is carried out at a hydrogen pressure of 4.0 MPa, a temperature of 400 ° C, a volumetric feed rate of 1.0 h ^-1 , a hydrogen to feed ratio of 1000 nm ³ / m ³ .

After passing through the isomerization reactor, the feed enters the dewaxing reactor, where it is contacted with a zeolite-based catalyst with a ZSM-11 structure with a molar ratio of SiO ₂ / Al ₂ O ₃ = 160, containing less than 0.5% wt. Na ₂ O, and a binder - alumina.

The catalyst is modified by platinum in an amount of 0.45% wt. and phosphorus in an amount of 5% wt. in terms of P ₂ O ₅ .

The dewaxing is carried out at a hydrogen pressure of 4.0 MPa, a temperature of 370 ° C, a volumetric feed rate of 1.5 h ^-1 , the ratio of hydrogen to feed 1000 nm ³ / m ³ .

Example 2

The proposed method is carried out, as in example 1, in two successive reactors. Gach with a melting point of + 52 ° C is used as raw material. When conducting tests in the first portion of the raw material is introduced an organic nitrogen compound in an amount of 3% wt. by weight of the catalyst in terms of nitrogen.

The catalyst for the isomerization stage is crystalline silicoaluminophosphate with the SAPO-11 structure introduced into the aluminum oxide support and modified with platinum in an amount of 0.5% wt.

The catalyst stage dewaxing prepared on the basis of a zeolite with a structure of ZSM-11 with a molar ratio of SiO ₂ / Al ₂ O ₃ = 160, containing less than 0.5% wt. Na ₂ O, and a binder - alumina.

The catalyst is modified by platinum in an amount of 0.45% wt. and phosphorus in an amount of 5% wt. in terms of P ₂ O ₅

Example 3

The proposed method is carried out, as in example 1, in two successive reactors. Paraffins with a melting point of + 56 ° C are used as raw materials.

The catalyst for the isomerization stage is a zeolite of the ZSM-12 type with a molar ratio of SiO ₂ / Al ₂ O ₃ = 60, containing less than 0.05% wt. Na ₂ O, with a binder - alumina. The catalyst is modified with barium in an amount of 3% wt. in terms of BaO, and palladium in an amount of 1.5% wt.

The catalyst stage dewaxing is zeolite ZSM-5 with a ratio of SiO ₂ / Al ₂ O ₃ = 140, containing less than 0.05% wt. Na ₂ O with aluminum oxide binder.

The catalyst is phosphorus modified in an amount of 5% wt. in terms of P ₂ O ₅ and palladium in an amount of 1.5% wt.

Example 4

The proposed method is carried out, as in example 1, in two successive reactors. Gach with a melting point of + 52 ° C is used as raw material.

The catalyst for the isomerization stage is zeolite beta with a molar ratio of SiO ₂ / Al ₂ O ₃ = 80, containing less than 0.05% wt. Na ₂ O, with a binder alumina and zirconia, modified with platinum in an amount of 0.4% wt. and strontium in an amount of 3% wt. in terms of SrO.

The catalyst stage dewaxing prepared on the basis of a zeolite with a structure of ZSM-11 with a molar ratio of SiO ₂ / Al ₂ O ₃ = 160, containing less than 0.5% wt. Na ₂ O, and a binder - alumina.

Zeolite modified with platinum in the amount of 0.45% wt. and phosphorus in an amount of 5% wt. in terms of P ₂ O ₅ .

When conducting tests in the first portion of the raw materials of the dewaxing stage, an organic nitrogen compound is introduced in an amount of 3% wt. on the catalyst in terms of nitrogen.

Example 5

The proposed method is carried out in one reactor, since the technological parameters of the stages of isomerization and dewaxing are the same. In this case, the catalysts are placed in the reactor in a ratio of 2: 1, the feed passes sequentially through the catalyst bed of isomerization, and then dewaxing. Paraffins with a melting point of + 56 ° C are used as raw materials.

The catalyst for the isomerization stage is zeolite beta with a molar ratio of SiO ₂ / Al ₂ O ₃ = 80, containing less than 0.05% wt. Na ₂ O, with a binder - alumina. The catalyst is phosphorus modified in an amount of 5% wt. and platinum in an amount of 0.5% wt.

The catalyst stage dewaxing is a zeolite ZSM-22 with a molar ratio of SiO ₂ / Al ₂ O ₃ = 90, containing less than 0.05% wt. Na ₂ O, with a binder - alumina, modified with phosphorus in an amount of 3% wt. in terms of P ₂ O ₅ and palladium in an amount of 1% wt.

Example 6

The proposed method is carried out in one reactor, as described in example 5, since the technological parameters of the stages of isomerization and dewaxing are the same. Gach with a melting point of + 52 ° C is used as raw material.

The catalyst for the isomerization stage is crystalline silicoaluminophosphate with a SAPO-31 structure, with a binder alumina, modified with platinum in an amount of 0.45% wt.

The catalyst stage dewaxing is zeolite ZSM-22 with a molar ratio of SiO ₂ / Al ₂ O ₃ = 78, containing less than 0.05% wt. Na ₂ O, with a binder - alumina, modified with phosphorus in an amount of 5% wt. in terms of P ₂ O ₅ and platinum in the amount of 0.45% wt.

Example 7

The proposed method is carried out in one reactor, as described in example 5, since the technological parameters of the stages of isomerization and dewaxing are the same. Paraffins with a melting point of + 56 ° C are used as raw materials. In the first portion of the raw material is introduced an organic nitrogen compound in an amount of 1.5% wt. by weight of isomerization and dewaxing catalysts in terms of nitrogen.

The catalyst for the isomerization stage is crystalline silicoaluminophosphate with a SAPO-31 structure, with a binder alumina, modified with platinum in an amount of 0.45% wt.

The catalyst stage dewaxing is zeolite ZSM-5 with a ratio of SiO ₂ / Al ₂ O ₃ = 140, containing less than 0.05% wt. Na ₂ O with aluminum oxide binder.

The catalyst is phosphorus modified in an amount of 5% wt. in terms of P ₂ O ₅ and palladium in an amount of 1.5% wt.

Example 8

The proposed method is carried out, as in example 1, in two successive reactors. Gach with a melting point of + 52 ° C is used as raw material.

The catalyst for the isomerization stage is a zeolite of the ZSM-12 type with a molar ratio of SiO ₂ / Al ₂ O ₃ = 60, containing less than 0.05% wt. Na ₂ O, with a binder - alumina. The catalyst is phosphorus modified in an amount of 6% wt. in terms of P ₂ O ₅ and platinum in the amount of 0.4% wt.

The catalyst for the dewaxing step is crystalline silicoaluminophosphate with a SAPO-11 structure, with a binder alumina, phosphorus modified in the amount of 7% wt. in terms of P ₂ O ₅ the weight of the carrier and platinum in the amount of 0.4% wt.

Example 9

The proposed method is carried out in one reactor, as described in example 5, since the technological parameters of the stages of isomerization and dewaxing are the same. Paraffins with a melting point of + 56 ° C are used as raw materials. When conducting tests in the first portion of the raw material is introduced an organic nitrogen compound in an amount of 2% wt. by weight of the catalyst in terms of nitrogen.

The catalyst for the isomerization stage is crystalline silicoaluminophosphate with a SAPO-11 structure, with a binder alumina, modified with platinum in an amount of 0.5% wt.

The catalyst stage dewaxing is zeolite ZSM-22 with a molar ratio of SiO ₂ / Al ₂ O ₃ = 78, containing less than 0.05% wt. Na ₂ O, with a binder - alumina, modified with phosphorus in an amount of 5% wt. in terms of P ₂ O ₅ and platinum in the amount of 0.45% wt.

Example 10

The proposed method is carried out, as in example 1, in two successive reactors. Gach with a melting point of + 52 ° C is used as raw material.

The catalyst for the isomerization stage is fluorinated alumina modified with platinum in an amount of 0.5% wt.

The catalyst for the dewaxing step is crystalline silicoaluminophosphate with a SAPO-11 structure, with a binder alumina, phosphorus modified in the amount of 7% wt. in terms of P ₂ O ₅ the weight of the binder and platinum in the amount of 0.4% wt.

Example 11

The proposed method is carried out, as in example 1, in two successive reactors. Paraffins with a melting point of + 56 ° C are used as raw materials.

The catalyst for the isomerization stage is a zeolite of the ZSM-12 type with a molar ratio of SiO ₂ / Al ₂ O ₃ = 60, containing less than 0.05% wt. Na ₂ O, with a binder - alumina. The catalyst is modified with barium in an amount of 3% wt. in terms of BaO, and palladium in an amount of 1.5% wt.

The catalyst for the dewaxing stage is crystalline silicoaluminophosphate with a SAPO-31 structure, with a binder alumina, phosphorus modified in an amount of 3% wt. in terms of P ₂ O ₅ and palladium in an amount of 2.0% wt.

Example 12 (comparative).

Similar to example 2, but using catalysts without modification with nitrogen at the stage of isomerization and phosphorus at the stage of dewaxing.

As follows from table 1, the proposed method allows to increase the yield of the oil fraction while improving the quality indicators - pour point and viscosity index. The conditions and parameters of the process make it possible to implement it at the enterprises of the industry.

Table 1
The results and conditions of the process of obtaining the basis of lubricating oils Example No. Stage temperature, ° С Volumetric feed rate, h ^-1 The exit fraction, boiling. above 360 ° C The pour point of the oil fraction, ° C Oil fraction viscosity index Isomer. Deparaf. Isomer. Deparaf. 1 400 370 1,0 1,5 52 -25 155 2 350 360 0.5 1,0 48 -35 142 3 330 375 0.8 1,0 38 -24 135 4 340 360 0.7 1,2 42 -25 138 5 360 360 0.7 0.7 45 -23 145 6 370 370 1,0 1,0 49 -thirty 140 7 360 360 0.8 0.8 fifty -28 150 8 360 370 0.7 0.9 47 -26 148 nine 350 350 0.5 0.5 51 -36 149 10 400 350 0.7 1,0 53 -28 158 eleven 330 350 0.5 1,2 43 -26 139 12 (comp.) 350 360 0.5 1,0 32 -20 130

Claims (6)

1. A method of obtaining a base of lubricating oils from high-paraffin raw materials, previously passed the stage of hydrotreating, including the stage of isomerization and dewaxing, carried out at elevated temperatures and excess pressure of hydrogen, in the presence of catalysts modified with metals of group VIII of the Periodic system, characterized in that the isomerization stage is used catalyst based on fluorinated alumina, or silicoaluminophosphate, or zeolite, modified with a metal of group II of the Periodic system emy or inorganic phosphorus compound, used in the dewaxing stage catalyst based on silicoaluminophosphate or zeolite modified with an inorganic phosphorus compound. 2. The method according to claim 1, characterized in that the zeolite catalysts used in the isomerization stage are modified with metals of group II of the Periodic system in an amount of 0.3-5 wt.% In terms of oxides, or with an inorganic phosphorus compound in an amount of 3-10 wt.% in terms of P ₂ O ₅ . 3. The method according to claims 1 and 2, characterized in that the catalysts used in the dewaxing stage are modified with an inorganic phosphorus compound in an amount of 3-10 wt.% In terms of P ₂ O ₅ . 4. The method according to claims 1 to 3, characterized in that the catalysts used in the stages of isomerization and dewaxing or in one of them are modified with organic nitrogen compounds in an amount of 0.5-7 wt.% In terms of nitrogen. 5. The method according to claims 1-4, characterized in that as the metals of group VIII of the Periodic system in the catalysts at the stages of isomerization and dewaxing use Pt or Pd in an amount of 0.1-2 wt.% 6. The method according to claims 1-5, characterized in that paraffin waxes and paraffins, including synthetic ones, are used as raw materials, the stages of isomerization and dewaxing are carried out at a temperature of 320-415 ° C, a partial pressure of hydrogen of 3.0-7, 0 MPa, with a volumetric feed rate of 0.5-1.5 h ^-1 , the flow rate of hydrogen to feed 500-2000 nm ³ / m ³