Description:TECHNICAL FIELD:
The present invention relates to the field of lubricants. In particular, the present invention relates to a high performance gas holder oil composition for lubrication and sealing of the rim of the piston and allied equipments in blast furnace/coke oven gas holders of steel plants. Further, the composition of the formulated gas holder oil is compatible with the materials of construction of the gas holders and the seals and protects the metal surfaces from rust and corrosion.

BACKGROUND:
Gas holders have an important role to play in the steel plant industry as it is used for storing gases and adjusting the pressure of the piped network wherein the use of thin oil sealing dry gas holder is required. The advantage of Gas Holder lies in production plant where it removes the need to produce gas continuously for usage and thus the gas is stored and acts as a buffer. Basically, the Gas Holder comprises of two major components (1) A Closed Vessel at the top and open in the base that holds the gas (2) A Static Tank over which the closed vessel moves up and down. The sealing oil has an important role to play in the lubricating and sealing of the gas holders, affecting its performance to a great extent. The coke oven gas holder has many complex components and moving parts (piston top) which moves with the aid of guide rollers and hence requires lubrication for upward and downward movement. The gas holder oil also needs to lubricate the guide rollers, rails and lubricate the hydraulic pump that is employed for pumping the oil on the top and back and so on. Thus, in the current invention it relates to sealing action, lubrication of the roller and the guides, imparting anti-wear characteristics to the pump. On account of these additional requirements, besides sealing action, the proposed gas holder oil should resist oxidation and corrosion in presence of corrosive gases and emulsification in presence of water. Besides all important requirements of gas holder oil, the retention of viscosity during the usage is important as it can be diluted by coke oven gases [ H2 (50-58%), CH4 (22-26%), N2 (6-9%), CO (6-11%), SO2].

US20070049506A1 discloses a lubricating composition comprising a base oil, (A) one or more kinds of compounds selected from phenolic antioxidants and aminic antioxidants, and (B) an ester compound having a disulfide structure.

CN109439392A discloses compound modification agents and preparation method thereof that a kind of waste hydraulic oil is reused in gas cabinet sealing oil.

EP2053117A1 discloses a lubricant composition containing a lubricant base oil and 0.5 to 10 mass% of (A) an ethylene/a-olefin copolymer having a number average molecular weight of 2, 800 to 8, 000, in which the lubricant base oil used here has a kinematic viscosity at 100°C of 1.5 to 40 mm2/s, a viscosity index of 100 or more, a pour point of -25°C or lower, and a sulfur content of 0.01 mass% or less,

US10316712B2 discloses lubricant compositions that include combinations of lubricant additives that are effective at improving the surface finish of a range of manufactured materials and equipment. In particular, friction modifiers and antiwear additives are employed to decrease surface roughness of additive manufactured (AM), e.g., 3D printed, materials and equipment in concert with maximizing energy efficiency.

WO2007050451A2 discloses a rust inhibitor providing a pass in the TORT B rust test, comprising a solubility improver, a mixture of amine phosphates, and an alkenyl succinic compound. A finished lubricant comprising the rust inhibitor and a lubricating base oil. A finished lubricant having a kinematic viscosity at 40°C between about 90 and 1700 cSt that passes the TORT B rust test, comprising a highly paraffinic base oil and a solubility improver having an aniline point less than 50°C. A finished lubricant that passes the TORT B rust test, comprising a Fischer-Tropsch wax, oligomerized olefins, or mixture thereof and a solubility improver.

None of the prior arts are related to composition of coke oven gas holder oil for steel plants and a need is felt to develop a gas holder sealing oil composition to overcome the shortcoming associated with existing sealing oils in the market to enhance the performance of steel plants.

SUMMARY OF THE INVENTION:
An aspect of the present invention provides a gas holder lubricating oil composition comprising:
a. 0.02 to 0.2% of a corrosion inhibitor;
b. 0.001 to 0.25% of a defoamant;
c. 0.001 to 0.05 % of a demulsifier; and
d. mixture of base oils.

These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS:
The above and other features, aspects, and advantages of the present disclosure will be better understood regarding to the following description, and accompanying drawings where:

Figure 1. Percentage Viscosity Retention of Gas holder Oils in the presence of coke oven gases

DETAILED DESCRIPTION:
For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below. The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. The term "at least one" is used to mean one or more and thus includes individual components as well as mixtures/combinations. Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps. The term “including” is used to mean “including but not limited to”. “including” and “including but not limited to” are used interchangeably.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods and materials are now described.
The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein.
The “Base oil” is the starting material for producing lubricants, and their properties greatly influence the performance and characteristics of the finished lubricant. They are typically derived from crude oil but can also be made from synthetic or bio-based sources.
The “Group I base oil” are mineral oils derived from petroleum crude and prepared through solvent refining and hydro finishing. They typically have a viscosity index (VI) from 90 to 105.
The “Group V base oil” comprise all base oils not included in Groups I, II, III or IV. Therefore, various synthetic esters, alkylated naphthalenes, oil-soluble polyalkylene Glycols, polyalkylene glycols (PAGs), phosphate esters and others fall into this group.
The term “Corrosion inhibitor” refers to compounds that prevent the conditions that would cause corrosion or rust, to occur.
The term “Antioxidant” refers to compounds that are designed to prolong the life of a lubricant by increasing the oxidative resistance of the base oil.
The term “Pour point depressant” refers to the compounds that are used to allow the use of petroleum based mineral oils at lower temperatures.
The term “Defoamant” refers to is a chemical compound that reduces and hinders the formation of foam in industrial process liquids.
The term “Demulsifier” refers to chemical compounds that break the oil emulsion into - oil and water.
The term “Antiwear” compound refers to chemical compounds that form a protective film on the surface to minimize wear and loss of metal surfaces.
Base oils are commercially available API group I base oils selected from BS150 and SN850 and API group V base oils selected from Heavy Alkyl Benzene, Neopolyol esters and oil-soluble polyalkylene Glycol.
In an embodiment, the present invention provides a gas holder lubricating oil composition comprising:
a. 0.02 to 0.2% of a corrosion inhibitor;
b. 0.001 to 0.25% of a defoamant;
c. 0.001 to 0.05 % of a demulsifier; and
d. mixture of base oils.

In another embodiment of the present invention, the composition comprises 0.001 to 1.0 % of a pour point depressant and 0.05 to 2.0 % of an antiwear compound.

In another embodiment of the present invention, the mixture of base oils comprises base oils of API Group I and API Group V.

In another embodiment of the present invention, the base oils of API Group I are selected from BS150 and SN850 or a mixture thereof.

In another embodiment of the present invention, the base oils of API Group V are selected from Heavy Alkyl Benzene, Neopolyol esters and oil-soluble polyalkylene Glycol or a mixture thereof.

In another embodiment of the present invention, the base oils of API Group I are present in a range of 55 to 67 % and base oils of API Group V are present in a range of 30 to 45% of total composition.

In another embodiment of the present invention, the corrosion inhibitor is succinic acid semi-ester derivative compound selected from a group consisting of alkenyl succinic acid, and/or alkenyl succinic acid ester.

In another embodiment of the present invention, the pour point depressant is alkyl methacrylate derivative selected from group consisting of poly methacrylate, polyacrylamide, alkyl methacrylate derivative, poly alkyl methacrylate derivative.

In another embodiment of the present invention, Defoamant is an ashless alkyl silicone selected from group consisting of commercially available silicone, poly siloxane, poly dimethyl siloxane.

In another embodiment of the present invention, the demulsifier is an ethylene oxide/propylene oxide copolymer selected from condensed polymeric alcohol, ester of fatty acid, fatty alcohol alkoxylated with alkylene oxide.

In another embodiment of the present invention, the antiwear compound is a sulphur & phosphorus-based derivative selected from group consisting of C6-C10 alkyl phosphates, 1-propene,2-methyl-, sulfurized, 1,3,4-thiadiazole.

Examples:
The disclosure will now be illustrated with working examples, which are intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure.
Example I: Preparation process of gas holder lubricating oil composition.
The examples (1 to 33) are listed in Table 1– 4 and these examples were prepared by mixing the components in percentage by weight.
The base oils used in the examples are of API Group I, II and Group V types or mixture thereof. These base oils are commercially available in the market. The array of commercially available additives and additive systems were selected in various combinations to achieve best performance. The additives includes antiwear, rust & corrosion inhibitors, antioxidants, metal deactivator, pour point depressant, demulsifier, defoamant, etc.

The candidate blends were prepared and evaluated for various physico-chemical tests including performance properties such as kinematic viscosity, pour point, flash point, foaming characteristics, rust test, water separability characteristics and tribological tests as per standard antiwear tests.

Table 1: The composition of the various candidate gas holder lubricating oils.
Component API Group I (BS150) Base Oil API Group V (Heavy Alkyl Benzene) Rust Inhibitor (succinic acid derivative) Demulsifier ( polyoxyethylene-polyoxypropylene fatty alcohol) Defoament
(alkyl silicone) Total
Example 1 65 35

Nil Nil 0.02
100
Example 2 65 34.99 0.01

Nil 0.02 100
Example 3 65 34.98 0.02 Nil 0.02 100
Example 4 65 34.97 0.03 Nil 0.02 100
Example 5 65 34.96 0.04 Nil 0.02 100
Example 6 65 34.955 0.04 0.005

0.02 100
Example 7 65 34.95 0.04 0.01 0.02 100
Example 8 65 34.94 0.04 0.02 0.02 100
Example 9 65 34.91 0.04 0.05 0.02 100
Example 10 65 34.86 0.04 0.1 0.02 100

Table 2: The composition of the various candidate gas holder lubricating oils (comparative examples).
Component API Group II (N 500) Base Oil Poly isobutylene polymer Rust Inhibitor-
(succinic acid derivative) Rust Inhibitor-
(sulfonate derivative) Metal passivator Demulsifier
( polyoxyethylene-polyoxypropylene fatty alcohol) Pour point depressant
(alkyl methacrylate derivative) Defoament
(alkyl silicone) Total
Example 11 87.43 12.5 0.05 - - Nil Nil 0.02 100
Example 12 87.33 12.5 0.05 - - 0.05 0.05 0.02 100
Example 13 87.23 12.5 0.05 - - 0.1 0.1 0.02 100
Example 14 87.27 12.5 - 0.01 0.05 0.05 0.1 0.02 100
Example 15 87.23 12.5 - 0.05 0.05 0.05 0.1 0.02 100

Table 3: The composition of the various candidate gas holder lubricating oils.
Component API Group I (SN850) Base Oil API Group V Base oil
(Neopolyol esters) Rust Inhibitor
(succinic acid derivative) Demulsifier
( polyoxyethylene-polyoxypropylene fatty alcohol) Pour point depressant
(alkyl methacrylate derivative) Antiwear
(sulphur & phosphorus-based derivative) Defoamant
(alkyl silicone) Total
Example 16 60 39.88
0.05

0.05

Nil Nil 0.02

100
Example 17 60 39.83 0.05 0.05 0.05

Nil 0.02 100
Example 18 60 39.78 0.05 0.05 0.1 Nil 0.02 100
Example 19 60 39.68 0.05 0.05 0.2 Nil 0.02 100
Example 20 60 39.68 0.05 0.05 0.1 0.1

0.02 100
Example 21 60 39.28 0.05 0.05 0.1 0.5 0.02 100
Example 22 60 38.78 0.05 0.05 0.1 1 0.02 100
Example 23 60 38.28 0.05 0.05 0.1 1.5 0.02 100
Example 24 60 37.78 0.05 0.05 0.1 2 0.02 100

Table 4: The composition of the various candidate gas holder lubricating oils
Component API Group I (BS150) Base Oil API Group V Base oil (oil-soluble polyalkylene Glycol Group V base oil) Rust Inhibitor
(succinic acid derivative)
Demulsifier
( polyoxyethylene-polyoxypropylene fatty alcohol) Pour point depressant
(alkyl methacrylate derivative) Antiwear
(sulphur & phosphorus-based derivative)
Defoament
(alkyl silicone) Total
Example 25 59.83 40
NIL 0.05
0.1

Nil 0.02

100
Example 26 59.82 40 0.01
0.05 0.1 Nil 0.02 100
Example 27 59.78 40 0.05 0.05 0.1 Nil 0.02 100
Example 28 59.68 40 0.1 0.05 0.1 Nil 0.02 100
Example 29 59.58
40 0.2 0.05 0.1 0.1

0.02 100
Example 30 59.28 40 0.05 0.05 0.1 0.5 0.02 100
Example 31 58.78 40 0.05 0.05 0.1 1 0.02 100
Example 32 58.28 40 0.05 0.05 0.1 1.5 0.02 100
Example 33 57.78 40 0.05 0.05 0.1 2 0.02 100

Example II: ASTM test methods performed on various gas holder lubricating oils.
The kinematic viscosity was tested as per ASTM D 445. The viscosity index of the composition found to be >90 as per ASTM D 2270. The pour point of the compositions was determined by ASTM D 97 and was found to be above (-) 15° C which provides the low temperature performance of the composition when the oil is used at conditions where the ambient is low. The water separability behavior or demulsibility test was carried out as per ASTM D 1401 and was found to vary for various compositions from a time period of 10 minutes to 25 minutes with different amount of oil, water and emulsion separation. The water separation characteristics as determined by ASTM D 1401 where the turbulence caused during pumping and circulation of the lubricating oil in gas holder system which can cause emulsion forming tendency therefore gas holder oil must possess excellent water shedding property during extended operation. The inferior water separation property of the gas holder oil composition can cause various issues in field such as rusting, leaching of additive system, sludge generation, clogging of the filters used in operation, inferior film formation on critical equipment parts and thereby leading to insufficient performance of oil lubrication. Rust prevention characteristics of the composition were studied by ASTM D 665.

The tribological evaluation of the compositions were performed for screening of the samples for wear scar diameter by ASTM D 4172A and Stick Slip test methods. The stick-slip test is used to determine the frictional characteristics of oils by Cincinnati Lamb friction test, the ratio of static to dynamic friction is determined. To avoid stick-slip, a ratio of 1 must not be exceeded; smaller values enable easy startup and a smooth transition from rest to movement. The Cincinnati Machine Company defines the upper limit of this test to be a ratio of 0.8. The gas holder oil compositions were found to have poor, moderate and excellent property in terms of, wear scar diameter and anti-stick-slip properties as per the standard test methods.

Table 5. Tests as per ASTM Test Methods for examples of Table 1
Property Appearance Colour K.Vis@40°C, cSt K.Vis @ 100°C, cSt Viscosity index TAN, mg KOH/gm Demulsibility @ 82°C Rust test
Method Visual D 1500 D 445 D 445 D 2270 D 974 D 1401 D 665B
Example 1 Clear L3.0 120.5 13.06 102 0.04 Fail Fail
Example 2 Clear L3.0 120.55 13.07 102 0.05 Fail Fail
Example 3 Clear L3.0 120.54 13.08 102 0.06 Fail Fail
Example 4 Clear L3.0 120.58 13.06 102 0.06 Fail Fail
Example 5 Clear L3.0 120.67 13.08 102 0.06 Fail Pass
Example 6 Clear L3.0 120.52 13.07 102 0.06 40-30-10 (30) Pass
Example 7 Clear L3.0 120.58 13.07 102 0.06 40-32-8(20) Pass
Example 8 Clear L3.0 120.63 13.05 102 0.06 40-38-2 (10) Pass
Example 9 Clear L3.0 121.01 13.04 101 0.06 40-40-0(10) Pass
Example 10 Clear L3.0 121.05 13.07 102 0.06 40-40-0(10) Pass
Table 6. Tests as per ASTM Test Methods for examples of Table 2
Component Appearance Colour K.Vis@40°C, cSt K. Vis @ 100°C, cSt Viscosity index TAN, mg KOH/gm Demulsibility @ 82°C Rust test Pour Point, °C
Example 11 Clear L0.5 116.59 13.95 119 0.05 40-40-0 (30) Pass -12
Example 12 Clear L0.5 116.60 13.96 119 0.06 40-40-0 (15) Pass -18
Example 13 Clear L0.5 116.65 13.97 119 0.07 40-40-0 (10) Pass -21
Example 14 Clear L0.5 116.45 13.87 118 0.02 40-40-0 (10) Fail -21
Example 15 Clear L0.5 116.42 13.88 118 0.02 40-40-0 (10) Pass -21

Table 7. Tests as per ASTM Test Methods for examples of Table 3

Property Appearance Colour K.Vis@40°C, cSt K.Vis @ 100°C, cSt Viscosity index TAN, mg KOH/gm Demulsibility @ 82°C Rust test Pour point, °C Wear scar diameter, mm Stick Slip Ratio
Method Visual D 1500 D 445 D 445 D 2270 D 974 D 1401 D 665B D 97 4172A CM
Example 16 Clear 1.5 123.1 12.53 92 0.06 40-38-2(10) Pass -12 - -
Example 17 Clear L 2.0 123.12 12.53 92 0.07 40-40-0 (10) Pass -15 - -
Example 18 Clear L 2.0 123.16 12.54 92 0.08 40-39-1(10) Pass -18 - -
Example 19 Clear L 2.0 123.24 12.55 92 0.08 40-40-0(10) Pass -18 - -
Example 20 Clear L 2.0 123.34 12.54 92 0.08 40-37-3(10) Pass -18 0.65 2.1
Example 21 Clear L 2.0 123.5 12.52 92 0.32 40-39-1(15) Pass -18 0.55 1.5
Example 22 Clear 2 123.55 12.53 92 0.44 40-38-2 (10) Pass -18 0.45 1.2
Example 23 Clear 2 123.58 12.56 92 0.58 40-40-0(10) Pass -18 0.35 0.8
Example 24 Clear 2.5 123.65 12.57 92 0.72 40-40-0(10) Pass -18 0.32 0.79
Table 8. Tests as per ASTM Test Methods for examples of Table 4
Property Appearance Colour K.Vis@40°C, cSt K.Vis @ 100°C, cSt Viscosity index TAN, mg KOH/gm Demulsibility @ 82°C Rust test Pour point, °C Wear scar diameter, mm Stick Slip Ratio
Method Visual D 1500 D 445 D 445 D 2270 D 974 D 1401 D 665B D 97 4172A CM
Example 25 Clear 2 116.5 13.76 117 0.2 40-38-2(10) Fail -18 - -
Example 26 Clear L 2.5 116.55 13.79 117 0.21 40-40-0 (10) Fail -18 - -
Example 27 Clear L 2.5 116.58 13.78 116 0.22 40-39-1(10) Fail -18 - -
Example 28 Clear L 2.5 116.6 13.77 116 0.23 40-40-0(10) Pass -18 - -
Example 29 Clear L 2.5 117.1 13.78 116 0.26 40-37-3(10) Pass -18 0.6 2
Example 30 Clear L3.0 117.12 13.75 115 0.35 40-37-3(10) Pass -18 0.5 1.4
Example 31 Clear L3.0 116.25 13.78 117 0.42 40-38-2 (10) Pass -18 0.44 1
Example 32 Clear L3.0 116.5 13.82 117 0.55 40-40-0(10) Pass -18 0.35 0.8
Example 33 Clear 3 116.1 13.77 117 0.7 40-40-0(10) Pass -18 0.3 0.78

Table 9. Performance of the candidate gas holder oil in the coke oven gas holder in a steel plant
S.No. Properties Test Method Fresh After 7 days After 15 days After 30 days
1. Appearance Visual Clear Clear Clear Clear
2. Color ASTM D 1500 2.0 L2.5 3.0 L 3.5
3. Kinematic Viscosity at 40° C, mm2/s ASTM D 445 121.52 110.78 90.23 89.23
4. Kinematic Viscosity at 100° C, mm2/s ASTM D 445 12.54 11.71 10.51 10.44
5. Viscosity Index ASTM D 2270 94 93 98 99
6. Total Acid Number, mgKOH/gm ASTM D 974 0.08 0.15 0.20 0.21
7. Wear Metal Analysis, ppm
-Fe, Cr, Ni, Al, Cu ASTM D 5185 <2 <2 <2 <2

ADVANTAGES OF THE INVENTION
• Better Water separation.
• Resistance to gas solubility.
• Inherent Anti-wear characteristics.
• Viscosity retention in presence of hydrocarbon gases,
• Longer drain interval.
, Claims:1. A gas holder lubricating oil composition comprising:
e. 0.02 to 0.2% of a corrosion inhibitor;
f. 0.001 to 0.25% of a defoamant;
g. 0.001 to 0.05 % of a demulsifier; and
h. mixture of base oils.

2. The composition as claimed in claim 1, wherein the composition comprises 0.001 to 1.0 % of a pour point depressant and 0.05 to 2.0 % of an antiwear compound.

3. The composition as claimed in claim 1, wherein the mixture of base oils comprises base oils of API Group I and API Group V.

4. The composition as claimed in claim 3, wherein the base oils of API Group I are selected from BS150 and SN850 or a mixture thereof.

5. The composition as claimed in claim 3, wherein the base oils of API Group V are selected from Heavy Alkyl Benzene, Neopolyol esters and oil-soluble polyalkylene Glycol or a mixture thereof.

6. The composition as claimed in claim 3, wherein the base oils of API Group I are present in a range of 55 to 67 % and base oils of API Group V are present in a range of 30 to 45 % of total composition.

7. The composition as claimed in claim 1, wherein the corrosion inhibitor is succinic acid semi-ester derivative compound selected from a group consisting of alkenyl succinic acid and/or alkenyl succinic acid ester.

8. The composition as claimed in claim 2, wherein the pour point depressant is alkyl methacrylate derivative selected from group consisting of poly methacrylate, polyacrylamide, alkyl methacrylate derivative, poly alkyl methacrylate derivative.

9. The composition as claimed in claim 1, wherein the defoamant is an ashless alkyl silicone selected from group consisting of commercially available silicone, poly siloxane, poly dimethyl siloxane.

10. The composition as claimed in claim 1, wherein the demulsifier is an ethylene oxide/propylene oxide copolymer selected from condensed polymeric alcohol, ester of fatty acid, fatty alcohol alkoxylated with alkylene oxide.

11. The composition as claimed in claim 2, wherein the antiwear compound is a sulphur & phosphorus-based derivative selected from group consisting of C6-C10 alkyl phosphates, 1-propene,2-methyl-, sulfurized, 1,3,4-thiadiazole.