RU2294355C1 - Compressor oil - Google Patents

Abstract

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: oil suitable for operation in piston-type air compressors under high-temperature and pressure difference conditions is composed of 2,6-di-t-butyl-4-methylphenol, 0.2-0.6%, ashless dialkyl- or dialkylphenyl dithiophosphate, 0.2-1.2%, C₈-C₉-alkylated phenyl-α-naphthylamine, 0.2-0.5%, and basic oil, in particular poly-α-olefin-based synthetic oil having cinematic viscosity above 10 mm²/s at 100°C. Oil may further contain 0.01-0.2% alkenylsuccinic acid monoester and 0.001-0.005% polymethylsiloxane.

EFFECT: increased resistance to formation of carbonaceous deposits in discharge lines of high-pressure air compressors.

2 cl, 2 tbl

Description

The invention relates to the field of petrochemistry, specifically the composition of compressor oil intended for use in reciprocating air compressors operating in the "heavy" mode. The main factors determining the “severity” of the oil in the air compressor are the temperature and pressure of the discharge air. Oils for “severe” conditions fall under the L-DAC category of ISO 6743 / 3A standard “Lubricants, industrial oils and related products (Class L). Classification. Part FOR. Group D (compressors). " Oils of the L-DAC category are designed for the most severe conditions of use permitted by the ISO 6743 / 3A standard: in compressors with an outlet pressure of more than 1 MPa, an outlet temperature of more than 140 ° C, but less than 160 ° C, a differential pressure of more than 3: 1 .

At present, high-pressure air compressors (20 mPa and higher) are manufactured and operated in Russia, which have more stringent temperature parameters (180-220 ° C) than is allowed by the ISO 6743 / 3A standard for the L-DAC category. The operation of these compressors on well-known oils presents significant difficulties due to the strong formation of carbon deposits (so-called carbon deposits) on valves, in the discharge air ducts and refrigerators of compressor units. The latter makes it necessary to frequently disassemble the compressor in order to clean the valves and discharge lines. Untimely removal of carbon deposits or their increased formation associated with the use of low-quality oil can lead to fires and explosions with the destruction of the compressor, which have serious consequences for staff.

Known oils for high pressure air compressors obtained from the residual epaulets of sulfur and low-sulfur oils using various refining processes. With this method of production, operational properties are created by selecting the chemical (mainly hydrocarbon) composition of oils obtained from oils of various fields (High-viscosity oils for air compressors of oxygen plants. Proceedings of VNIINP, issue 12, “Petroleum oils and additives to them”, 1970, p.142-155, publishing house "Chemistry").

These non-inhibited oil additives satisfactorily manifest themselves under “light” and “medium” operating conditions, but are not suitable for severe conditions.

More promising was the creation of the operational properties of oils using not only the properties of the base oil, but also additives.

Known lubricating oil for high-pressure gas compressors, consisting of the basis of a mixture of isoalkanes and naphthenes with the addition of polyisobutylene and as antiwear additives alkenylate acid or its derivatives in an amount of 0.05-5% (Japan Application No. 56-38393, class C 10 M 3/18, 1981).

The disadvantage of this oil is its low thermal oxidative stability, without which it is impossible to obtain good anti-stick properties.

Compressor oil is known for lubricating high pressure compressors in the production of polyolefin films. The oil contains 5-50 wt.% Polyisobutylene with a molecular weight of 500-15000, 0.1-1 wt.% Fatty acids containing 8-22 carbon atoms and 0.01-2 wt.% Antioxidant representing two or trisubstituted phenol (US Pat. UK No. 1338505, class C 10 M 1/24, C 5 F, 1973).

This oil behaves well when compressing a medium that does not contain oxygen (lower olefins), but due to high carbon formation it is completely unsuitable for high pressure air compressors.

The closest to the claimed composition of the components is lubricating oil, especially for steam turbines, consisting of a larger component of mineral lubricating oil and smaller amounts of well-known oil-soluble additives:

an aliphatic polycarboxylic acid with at least 12 carbon atoms,

- alkyl phenol,

- aromatic amine (including acyl-substituted phenyl-α-naphthylamine),

- dialkyldithiophosphate (including ashless)

(German patent No. 1594405, class C 10 M 1/48, 23 s, 1/01, 1974).

The disadvantage of this oil, as well as other known ones, is the increased formation of carbon deposits when used in heat-stressed high pressure piston air compressors.

The objective of the present invention is to develop a compressor oil composition having a reduced tendency to form carbon deposits in the discharge lines of heat-stressed high pressure piston air compressors.

To solve this problem, a base oil-based compressor oil containing 2,6-di-tert-butyl-4-methyl-phenol, ashless dialkyl or dialkylphenyl dithiophosphate, an alkylated phenyl-α-naphthylamine with an alkyl group of C ₈ -C ₉ , which according to the invention as a base oil contains a synthetic oil based on polyalphaolefins with a kinematic viscosity of more than 10 mm ² / s at 100 ° C in the following ratio, wt.%:

2,6-di-tert-butyl-4-methyl-phenol 0.2-0.6 Ashless dialkyl or dialkyl phenyl dithiophosphate 0.2-1.2 Alkylated phenyl-α-naphthylamine with alkyl group C ₈ -C ₉ 0.2-0.5 Base oil Up to 100

Moreover, the proposed compressor oil may contain, if necessary, 0.01-0.1 wt.% Acid alkenyl succinic ester and 0.001-0.005 wt.% Polymethylsiloxane.

The use of a synthetic oil based on polyalphaolefins with a kinematic viscosity of more than 10 mm ² / s at 100 ° C as a base oil can increase the resistance of compressor oil to air exposure at high temperatures, pressure and contact with metal surfaces, and thereby reduce the tendency to the formation of carbon deposits. In addition, the proposed oil has enhanced anti-wear properties and good ability to tighten gaps in the piston cylinder group.

The proposed compressor oil is prepared by mixing the components with stirring and a temperature of 60-80 ° C. The following is a description of the components used in the preparation of compressor oil:

- 2,6-di-tert.-butyl-4-methyl-phenol. A commodity-produced example of this product may be the additive Agidol-1, produced according to TU 38.5901237-90. It is a white crystalline powder, used as an antioxidant additive in lubricating oils and fuels. Melting point 69.5-70 ° C, crystallization temperature 69 ° C.

- Ashless dialkyl or dialkylphenyl dithiophosphate. Product examples of this product include ADTF additives according to TU 38.101105-84, VNIIP-715 according to TU 38.40143-83 and Irgalube 63 from Ciba. Additives are viscous liquids from brown to light brown in color.

- Alkylated phenyl-α-naphthylamine with an alkyl group of C ₈ -C ₉ . A product example of this product may be Ciba Irganox L 06. Solid melting point above 75 ° C

- Acid ester of alkenyl succinic acid. Product examples of this product may be: 15/41 according to TU 6-14-866-86, Irgacor L 12 from Ciba or Lubrizol® 859 from Lubrizol. It is a viscous liquid of yellow or light brown color. It is added to lubricating oils as an additive that suppresses rusting of metal surfaces in the presence of water.

- Polymethylsiloxane (additive PMS-200A). It is produced according to OST 6-02-20-79, added to lubricating oils to improve antifoam properties.

- Basis - synthetic oil based on aliphatic hydrocarbons with a viscosity of more than 10 mm ² / s at 100 ° C, for example, PAOM-12 oil according to TU 38.4011093-2003 or PAOM-20 according to TU38.401-58-42-92 or synthetic polyalphaolefin oil Synfluid PAO 25 CST MVP by Chevron Phillips.

To illustrate the essence of the proposed technical solution by the above method, 12 samples of the proposed compressor oil were prepared. Tables 1 and 2 show the compositions of the prepared samples and the test results. Table 1 shows the compositions and test results of oils prepared using PAOM-12 polyalphaolefin oil as a base (with a viscosity of 12 mm ² / s at 100 ° C), and table 2 shows the compositions and test results of oils prepared on a base polyalphaolefin PAOM-20 oil (with a viscosity of 20 mm ² / s at 100 ° C).

The prepared samples were tested using the method of assessing the tendency of oils to deposit formation on the Folders instrument according to GOST 23175. A 0.5 g sample of oil in a steel cup was placed on a sanded plate heated to 200 ° C or 210 ° C and heated for 72 or 45 hours. After testing, steel plates were washed with petroleum ether in a Soxhlet apparatus. It was found that the amount of products insoluble in petroleum ether formed in steel cups during such tests is in good agreement with the amount of carbon deposits formed on the valves during operation of the high-pressure high-pressure compressor VSW 2,3 / 230 on oils of different quality.

Tests on the Folders instrument were used as a method to predict the behavior of oils in the compressor discharge line.

Moreover, oils with a viscosity of 12 mm ² / s at 100 ° C were tested at a temperature of 200 ° C and a duration of 72 hours (table 1), and for oils with a viscosity of 20 mm ² / s at 100 ° C, the conditions were tightened: 210 ° C at duration of 45 hours (table 2).

In addition to samples based on polyalphaolefins, Table 1 shows the test results of petroleum oil with the claimed additive package and with a viscosity of 12 mm ² / s at 100 ° C. Table 2 shows the test results of petroleum oil with the claimed additive package and with a viscosity of 20 mm ² / s at 100 ° C. For comparison, table 1 shows the test results used in the compressor oil industry.

The data presented in the table confirm that the proposed compressor oil is significantly superior to commodity oils, as well as experimental oils based on mineral oils, in resistance to carbon deposits.

Table 1 Oil Components, wt.% Insoluble in petroleum ether when tested on a device according to GOST 23175 (200 ° C, 72 h, 0.5 g sample),% 2,6-di-tert-butyl-4-methyl-phenol Ashless dialkyl or dialkylphenyl dithiophosphate Alkylated phenyl-α-naphthylamine with C ₈ -C ₉ alkyl group Alkenyl succinic acid ester Polymethyl - Siloxane Base oil ADHF Irgalube 63 Suggested Samples Number one 0.2 1,2 - 0.2 - - Synthetic hydrocarbon based on aliphatic hydrocarbons, up to 100 2,5 2 0.6 0.2 - 0.5 - - 2.1 3 0.4 0.5 - 0.3 - - 0.9 four 0.4 0.5 - 0.3 0.01 0.001 one 5 0.4 0.5 - 0.3 0.1 0.005 1.3 6 0.4 0.3 0.3 0,03 0.002 0.8 7 0.4 0.5 - 0.3 0.05 0.002 Oil to 100 3,1 K2-24 according to TU 38.401-58-43-92 0.4 0.6 - - 0.002 16,2 K3-10 according to TU 38.401724-88 0.4 0.6 - - - 0.002 10.1

Claims (2)

1. A base oil-based compressor oil containing 2,6-di-tert-butyl-4-methyl-phenol, ashless dialkyl or dialkylphenyl dithiophosphate, an alkylated phenyl-α-naphthylamine with an alkyl group C ₈ -C ₉ , characterized in that as a base oil it contains a synthetic oil based on polyalphaolefins with a kinematic viscosity of more than 10 mm ² / s at 100 ° C in the following ratio of components, wt.%: 2,6-di-tert-butyl-4-methyl-phenol 0.2-0.6 Ashless dialkyl or dialkyl phenyl dithiophosphate 0.2-1.2 Alkylated phenyl-α-naphthylamine with C ₈ -C ₉ alkyl group 0.2-0.5 Base oil Up to 100 2. Oil according to 1, characterized in that it further restrains the acid ester of alkenyl succinic acid in an amount of 0.01-0.1 wt.% And polymethylsiloxane in an amount of 0.001-0.005 wt.%.