SYNERGISTIC DEPOSIT CONTROL ADDITIVE COMPOSITION FOR GASOLINE FUEL AND PROCESS THEREOF
FIELD OF INVENTION
The present invention relates to deposit control additive composition comprising of Poly isobutylene amine (PIBA) having average molecular weight of 800 and a Mannich Base as synergistic component of deposit control additive formulation. The invention further relates to a deposit control additive formulation comprising deposit control additive composition, fluidizer oil, dehazer, corrosion inhibitor and solvent which is blended with gasoline fuel to obtain fuel composition and process for preparation thereof.
BACKGROUND OF THE INVENTION
Deposits in the fuel delivery system and combustion chamber of an internal combustion engine can adversely affect the combustion performance in terms of power output and emissions. As a sequel to this, development of more effective fuel additives to prevent and /or reduce deposits is highly desirable.
Canadian Patent No. 2,089,833; US Patent. No. 5,697,988; US Patent. No. 5,873,917 and US Patent. No. 5,876,468, involves Mannich detergents, generally prepared by reaction of alkylphenols with aldehydes and amines, and polyether fluidizers for reduction of deposits in an engine combustion chamber and/or fuel delivery system.
US Patent. No. 6,179,885 discloses a composition, comprising: (I) an aromatic Mannich compound derived from: (A) a hydroxy containing aromatic compound; (B) an aldehyde or ketone and (C) a mixture of water and an amine, said amine containing at least one primary or secondary amino group; and (II) alcohol and the process for making the foregoing composition.
Mannich condensation reactions usually proceeding with the formation of high molecular weight products, by linear growth due to the use of mono-substituted phenols and an amine groups. Excess aldehyde may also react with amine groups to form imines or hydroxymethylamines. Accordingly, the properties of such polymeric compositions have principally been utilized in
heavier fuels such as heating and furnace oils, as described in US. Patent. No. 2,962,442, and in lubricating oils as disclosed in US Patent. Nos.3,036,003 and 3,539,633. None of these uses a sensitive carburetion system as is found in the gasoline-powered spark-ignition internal combustion system.
Mannich condensation products have often been employed as stabilizers, antioxidants, dispersants, or detergents in heavy hydrocarbon stocks. Use in lighter hydrocarbon stocks such as gasoline, has been disclosed in US Patent. Nos. 3,269,810 and 3,649,229.
US Patent No. 3,235,484 (Now US Patent No. Re. 26,330) describes the addition of certain disclosed compositions to refinery hydrocarbon fuel stocks for the purpose of inhibiting the accumulation of carbonaceous deposits in refinery cracking units. The primary inhibitors disclosed are mixtures of amides, imides and amine salts formed by reacting an ethylene polyamine with hydrocarbon substituted succinic acids or anhydride, whose hydrocarbon substituent has at least about 50 carbon atoms. As an adjunct for such primary carbonaceous deposit inhibitors is disclosed in said patent Mannich condensation products formed by reacting (1) alkylphenol, (2) an amine and (3) formaldehyde in the ratio of one mole alkylphenol and from 0.1-10 mole each of formaldehyde and amine "reactant.
US Patent. No. 3,368,972 describes dispersant-detergent additive for lubricating oils as high molecular weight Mannich condensation products from (1) high molecular weight alkyl-substituted hydroxyaromatic compounds whose alkyl-substituent has a molecular weight in the range of 600-3000, (2) a compound containing at least one NH group and (3) an aldehyde in the respective molar ratio of 1.0:0.1-10:1.0-10.
The high molecular weight Mannich condensation products referred to in US Patent. No.3,235,484 and US Patent. No. 3,368,972 has a drawback in their large-scale preparation and in their extended service used as lubricant addition agents under high temperature conditions encountered in Gasoline engines.
In the large-scale or plant preparation of such high molecular weight condensation products, especially in light mineral oil solvents, the resulting oil
concentrate solution of the condensation product either has or develops during storage haziness which is believed to be caused by un-dissolved or borderline (sparingly) soluble by-products which not only substantially incapable of removal by filtration but also severely resurrect product filtration rate.
When used in Gasoline engine crankcase lubricant oils and subject to high temperature in service use, piston ring groove carbonaceous deposits and skirt varnish tend to build up rapidly and prevent desirable long in-service use of such lubricant oils. US Patent. No. 4,038,044 discloses a combination of diamine and higher polyamine Mannich condensation products useful in gasoline as carburetor detergents and also to control intake valve deposits and quick-heat intake manifold deposits. The present invention details an additive composition comprising of PIBA and Mannich base, as a synergistic component of gasoline fuel/deposit control additive formulation which is mixed with gasoline fuel to obtain gasoline fuel composition
A process for preparation of novel Mannich Bases from hydrogenated and distilled Cashew Nut Shell Liquid (CNSL) for use as additive in liquid hydrocarbon fuels for removing and protecting build up of deposits on carburetor surfaces and intake valve systems in a gasoline powered engine system is reported by the Applicant in US Patent No 6,797,021.
The above prior art citations refer to the use of Mannich base in isolation or in combination with diamine for protecting build up of deposits on carburetor surfaces. The surprising results of the present invention is achieved by using Mannich bases and poly isobutylene amine as synergistic component of deposit control additive formulation to drastically control and reduce deposits on carburetor surfaces and keep port fuel injectors and intake valves clean in gasoline fueled spark ignition internal combustion engines.
OBJECTS OF THE INVENTION
The main object is to provide a deposit control additive composition for gasoline fuel to control and reduce deposits on carburetor surfaces and keep port fuel injectors and intake valves clean in gasoline fueled spark ignition internal combustion engines
An object of the invention is to provide the deposit control additive composition comprising of Mannich base and Poly iso butylene amine (PIBA) having average molecular weight of 800 as a synergistic component of the deposit control additive formulation.
Another object of the invention is to provide a deposit control additive formulation comprising of deposit control additive composition, fluidizer oil, dehazer, corrosion inhibitor and solvent.
Yet another object of the invention is to provide a fuel composition comprising gasoline fuel and deposit control additive formulation.
Still another object of the invention is to provide an easy and economical process for the preparation of fuel composition by blending deposit control additive formulation and gasoline fuel.
SUMMARY OF THE INVENTION
The present invention relates to deposit control additive composition comprising of Polyisobutylene amine (PIBA) having average molecular weight of 800 and Mannich base as a synergistic component of deposit control additive formulation comprising of components such as fluidizer oil, dehazer, corrosion inhibitor, and solvent. The invention also relates to a fuel composition comprising deposit control additive formulation and gasoline fuel. The invention further relates to a process for the preparation of fuel composition by blending at an ambient temperature gasoline fuel and deposit control additive formulation obtained by blending Mannich base, Poly iso butylene amine (PIBA), fluidizer oil, dehazer, corrosion inhibitor and solvent at a temperature ranging between 50°C to 60°C for a time period of up to 2 hours.
This deposit control additive formulation is highly miscible with gasoline fuel at room temperature and is mixed with fuel in the storage tanks, road tanks, railway tanks etc.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the objective, the present invention provides a deposit control additive composition as a synergistic component of Deposit control additive formulation comprising of:
a) Mannich base; and
b) Poly isobutylene amine (PIBA) having average molecular weight ranging between 700 to 1000 and preferably 800.
A deposit control additive composition further comprises of fluidizer oil, dehazer, corrosion inhibitor and solvent to provide a deposit control additive formulation.
An embodiment of the present invention provides a fuel composition, comprising of:
a) gasoline fuel ranging from 99.99 to 99.90 w/w %, and
b) deposit control additive formulation ranging from 0.01to 0.1 w/w%.
Another embodiment of the present invention provides fuel composition comprising of gasoline fuel selected from a group consisting of octane 88, octane 91, octane 95, and octane 96 and like fuels.
A gasoline fuel used in the fuel composition may further comprise of alcohol upto 10 w/w% of the fuel.
Yet another embodiment of the present invention consists of deposit control additive composition containing of PIBA to Mannich base in the ratio of about 1:0.2.
The Mannich base is derived from reaction of a hydrogenated and distilled Cashew Nut Shell Liquid (CNSL) or para substituted alkyl phenol with an aldehyde and an amine having at least one reactive hydrogen atom.
The preferable para substituted alkyl phenol is para-nonyl phenol, aldehyde is paraformaldehyde and amine is dibutylamine
Still another embodiment of the present invention provides fuel composition wherein the concentration of deposit control additive formulation
ranges from 100 to 1000 mg/lt having excellent performance in intake deposit test, PFI test, corrosion test as per ASTM D 665A carried out at room temperature, ASTM D 1094 Test of water reaction and the doped fuel meets the IS 2796:2000 specification of Indian gasoline fuel.
Further embodiment of the invention provides a process for the preparation of fuel composition, said process comprising steps of:
a) obtaining deposit control additive formulation of claim 2 by blending mannich base, polyisobutylene amine, fluidizer oil, dehazer and corrosion inhibitor and solvent in a suitable container at a temperature ranging between 50°C to 60°C for a time period of up to 2 hours, and
b) blending further at an ambient temperature the deposit control additive formulation of step(a) with gasoline fuel to obtain fuel composition.
The present invention provides the addition of Mannich bases derived from reacting hydrogenated and distilled Cashew Nut Shell Liquid (CNSL) or para-alkyl phenols with aldehyde and an amine to gasoline fuels adapted for use in gasoline engines comprising of a detergent Polyisobutylene amine (PIBA), fluidizer Oil, dehazer corrosion inhibitor and solvent which significantly improves the deposit control characteristics of the said fuel.
The present invention establishes that when Mannich base (dispersant) is incorporated in combination with detergent Polyisobutylene amine (PIBA), fluidizer Oil, dehazer, corrosion inhibitor and solvent into the gasoline fuel, deposit control characteristics related to port fuel injectors and intake valves cleanliness are improved drastically in comparison to the aforesaid components when added singularly to the gasoline fuel.
If Polyisobutylene amine (PIBA) is used alone then the intake valve deposits (IVD) are found to be 40 mg per valve in reference gasoline fuel having 250mg/lit of deposit control formulation in Mercedes Benz M111 engine test carried out as per CECF20A98. While at the same dosages level and at higher levels of Mannich Base alone, the IVD deposits are found to be more than 100 mg, which is, could not be reduced to the desired level of less than 50 mg. However, in the case of a combination of Mannich base and
Polyisobutylene amine (PIBA) doped in reference gasoline @ 250 mg/lt, IVD are drastically reduced to 7 mg per valve thereby establishing the synergistic effect of the deposit control additive composition used in the fuel.
A successful attempt has been made to develop a deposit control additive composition comprising Mannich bases derived from hydrogenated and distilled Cashew Nut Shell Liquid (CSNL), from commercially available para-substituted phenols and PIBA for gasoline fuel.
The alkyl phenols used in the process of preparation of Mannich bases are para-nonyl phenol or para-dodecyl phenol or hydrogenated and distilled Cashew Nut Shell Liquid (popularly known as CNSL). CNSL, on distillation, gives the pale yellow phenolic derivatives, which are a mixture of biodegradable unsaturated m-alkylphenols, including cardanol. Catalytic hydrogenation of these phenols gives a white waxy material, predominantly rich in tetrahydroanacardol, which is also known as hydrogenated CNSL. Mannich condensation products are prepared by the reaction of para-nonyl phenol or para-dodecyl phenol or the hydrogenated CNSL (hydrogenation of cashew nut shell liquid is carried out in an autoclave using conventional method of catalytic hydrogenation), an amine having at least one reactive hydrogen atom, and an aldehyde in the molar ratio of 1:0.1to10:0.1to10 at a temperature ranging from 70°C - 175°C for 6 to 12 hours in presence of a protic organic solvent. The process for the preparation of Mannich base from hydrogenated and distilled Cashew Nut Shell Liquid (CSNL) is reported by the Applicant in US Patent No 6,797,021.
Polyisobutylene amine (PIBA), which can be used in the present invention include those with average molecular weight of 700 to 1000. Preferred PIBA has average molecular weight of 800.

(Table Removed)
The fluidizer oil of the invention is preferably aromatic solvent. Toluene, xylenes and aromatic streams of refineries and preferably xylene
Dehazer is an ashless de-emulsifier having a mixture of polymers and copolymers designed to reduce the interaction of gasoline with water and to improve the water tolerance characteristics of treated gasoline. The typical properties are as follows:

(Table Removed)
Corrosion inhibitors (CI), which can be used in the present invention, include esters of succinic acid, imidazolines and alkyl benzotriazoles. Preferred corrosion inhibitors are those derived from esterification of succinic acid. Of these partial esters of succinic acid that has following characteristics is the most preferred:

(Table Removed)
The amount of the Mannich base in combination with PIBA in the present deposit control additive composition of the invention should be enough to provide desired control and reduction in deposit thereby establishing synergistic effect with the use of PIBA. This concentration is conveniently expressed in terms of weight percent of Mannich base based on the total weight of the additive formulation. A preferred concentration is from about 10 to about 50 weight percent. A more preferred range is from about 10 to about 20 weight percent
The concentration of Polyisobutylene amine (PIBA) in the deposit control additive formulations for fuel should also be enough to control the deposits to get desired intake valve deposits. This concentration is conveniently expressed in terms of weight percent of PIBA based on the total weight of the deposit control additive formulation A preferred concentration is from about 40 to about 90 weight percent. A more preferred range is from about 60 to about 80 weight percent.
A deposit control additive formulations for gasoline fuel in the present invention is prepared by blending deposit control additive composition with further components such as fluidizer oil, dehazer, corrosion inhibitor and solvent in a suitable container.
Dehazer is added to deposit control additive composition for fast separation of water from the fuel during transportation and storage to prevent premature blocking of fuel filters, corrosion, carburetor icing and possible fuel line freezing up when excessive water is carried into the fuel delivery system.
Dehazers are highly surface-active chemicals having limited solubility in water and fuel and tend to concentrate at the fuel-water interface. Therefore, these are added at a very low concentration. A preferred concentration is from about 1 to about 5 weight percent. A more preferred range is from about 1 to about 3 weight percent.
Corrosion can lead to severe problems in the storage tanks, pipelines and automobile fuel tanks. To prevent corrosion, inhibitors are added in relatively low concentrations. A preferred concentration in the package
composition is from about 1 to about 5 weight percent. A more preferred range is from about 1 to about 3 weight percent.
Conventional blending equipment and techniques may be used in preparing the deposit control additive formulation. In general, a homogeneous blend of the foregoing active components is achieved by merely blending the Mannich base component of the present invention with the PIBA , Fluidizer oil, dehazer, corrosion inhibitor and solvent of the present invention in a determined proportion at 40-50 deg C for 2 hrs.
The deposit control additive formulation is mixed with the gasoline fuel in a storage tanks or road tanks or railway tanks etc. in a concentration sufficient to reduce the deposit forming tendencies of the fuel. This is normally carried out at an ambient temperature.
The following examples are illustrative of the invention but not to be construed to limit the scope of the present invention. The present invention has been described in terms of its specific embodiments and certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of present invention.
EXAMPLES
Example 1:
Preparation of Deposit Control Additive Formulations:
Various different deposit control additive formulations for Gasoline fuel are prepared by blending different combinations of components such as detergent(PIBA), dipersant (Mannich BASE), fluidizer oil, dehazer, corrosion inhibitor and solvent in a suitable container at 50-60 Deg C with continuous stirring for 2 hrs. Details are enumerated as follows:
Formulation - 1: A combination of PIBA, fluidizer oil, dehazer and corrosion inhibitor in the ratio 70:28:1:1 was prepared without the addition of Mannich base.
Formulation - 2: A combination of Mannich base, fluidizer oil, dehazer and corrosion inhibitor in the ratio 70:28:1:1 was prepared without the addition of PIBA.
Formulation - 3: A combination of PIBA, CSNL based Mannich Base, fluidizer oil, dehazer and corrosion inhibitor in the ratio 70:15:13:1:1 was prepared. Mannich base was added to establish the synergistic effect of Mannich base with PIBA in the Intake valve deposit engine test.
Formulation - 4: A combination of PIBA, Nonyl phenol based Mannich Base, fluidizer oil, dehazer and corrosion inhibitor in the ratio 70:15:13:1:1 was prepared. Mannich base was added to establish the synergistic effect of Mannich base with PIBA in the Intake valve deposit engine test.
Formulation - 5: A combination of PIBA, Dodecyl phenol based Mannich Base, fluidizer oil, dehazer and corrosion inhibitor in the ratio 70:15:13:1:1 was prepared. Mannich base was added to establish the synergistic effect of Mannich base with PIBA in the Intake valve deposit engine test.
EXAMPLE 2
Evaluation Methodology
The complete evaluation of deposit control additive formulations was carried out in the gasoline fuel by assessing the performance in the following parameters:
a) Testing of deposit control additive formulation treated gasoline fuel as per National Standard IS 2796:2000: The regular gasoline fuel meeting Indian standard IS 2796:2000 specification was used for the evaluation of deposit control additive formulations and desired concentration of deposit control additive formulations was added to it. After the addition of deposit control additive formulations, the product was again tested as per IS 2796: 2000 specifications to confirm that addition of deposit control additive formulations in the desired concentration in gasoline fuel does not adversely affect its properties.
b) The compositions meeting IS 2796: 2000 specifications were additionally tested for following characteristics
i) WATER REACTION OF FUELS: This test is designed to measure water tolerance characteristics of gasoline fuel. It is a quick way to measure the ability of a fuel to separate rapidly from water after mixing under low shear conditions. Briefly the
procedure involves hand shaking of 80ml of gasoline fuel containing deposit control additive formulations with 20 ml of phosphate buffer solution for two minutes. After 5 minutes settling period, the fuel-water interface and water layer are rated for emulsion, the fuel phase and clarity.
ii) DYNAMIC CORROSION TEST: This test is carried out to evaluate the ability of gasoline fuel containing deposit control additive formulations to prevent rusting of ferrous parts when fuel comes in contact with water. Corrosion can lead to severe problems in storage tanks, pipelines tankers and automobile fuel tanks. The particles of rust can also clog fuel lines, filters carburetor orifices or jets. This evaluation procedure is based upon ASTM D-665-95 standard test method for mineral oils with modification so that the test is run at ambient temperature for fuels. 300 ml of the gasoline fuel containing deposit control additive formulations is stirred at 1000+ 50 rpm with 30 ml of distilled water for 24 hrs using polished steel spindle conforming to grade 1018 of ASTM A-108 specifications. After the test .the spindle is assessed for the corrosion.
c) Intake Valve Deposit Test using Mercedes Benz M111 Engine as per CEC F-20-A-98 : Intake valve deposit test using Mercedes Benz M111 engine as per CEC-F-20-A-98 is the internationally accepted standard test for assessing the performance of gasoline fuel containing deposit control additive formulations. The product giving lowest intake valve deposits is considered better in performance to control the intake valve deposits under field conditions.
d) Port Fuel Injector Fouling Bench Test: Port Fuel Injector bench test apparatus from SwRI is internationally accepted standard test for assessing the additive effectiveness and fouling tendency of gasoline for the port fuel injectors. The deposits that formed on the tip of the pintle-type injectors of certain engines restricted flow and caused
drivability and emission problems. This method carried out as per ASTM D 6421 and has excellent correlation with the ASTM D 5598 PFI vehicle test for the predictor of port fuel -injector fouling.
Following examples illustrate the preparation of some typical fuel compositions of the present invention and performance evaluation thereof:
EXAMPLE 3
The formulations prepared as per Example 1 were added in the gasoline fuel meeting IS 2796:2000 specification at 250mg/lit treat rate and the treated samples were tested as per national specifications [IS 2796:2000] to establish that the addition of these formulations does not have any deteriorating effect on the properties of gasoline fuel. The results are reported in Table 1 to 3.
TABLE-1

(Table 1 to 3 Removed)
EXAMPLE 4:
Gasoline fuel doped with deposit control additive formulations as prepared in Example -1 were also tested as per ASTM D1094 to measure the ability of the doped gasoline to separate water. The results are given in Table-4.
TABLE-4

(Table Removed)
EXAMPLE 5:
Dynamic Corrosion Test:
Gasoline fuel doped with deposit control additive formulations as prepared in Example - 1 were also tested as per ASTM D 665 (modified) to measure the ability of the doped gasoline to prevent corrosion. The results are given in Table-5.
TABLE-5

(Table Removed)
EXAMPLE 6:
The above formulations were evaluated for intake valve deposit (IVD) test using Mercedes Benz Mill engine as per CEC F-20-A-98. The test results are given in
Table-6.
TABLE-6

(Table Removed)
EXAMPLE-7
The above formulations were evaluated for port fuel injector fouling test using port fuel injector test apparatus from SwRI as per ASTM D 6421. The test results are given in Table-7.
TABLE-7
(Table Removed)

We claim
1. A deposit control additive composition as a synergistic component for
gasoline/ fuel comprising of:
a) Mannich base, and
b) Poly iso butylene amine (PIBA) having average molecular weight ranging between 700 to 1000 and preferably 800.

2. A deposit control additive formulation comprising a deposit control additive composition of claim 1, fluidizer oil, dehazer and corrosion inhibitor and solvent.
3. The composition of claim 1, wherein the ratio of PIBA to Mannich base is about 1:0.2.
4. The composition of claim 1, wherein the Mannich base is derived from reaction of a hydrogenated and dfstilled Cashew Nut Shell Liquid (CNSL) or para substituted alkyl phenol with an aldehyde and an amine having at least one reactive hydrogen atom
5. The composition of claim 4 wherein the preferable para substituted alkyl phenol is para-nonyl phenol, aldehyde is paraformaldehyde and amine is dibutylamine
6. A fuel composition, comprising of:
a. gasoline fuel ranging from 99.99 to 99.90 w/w % (w/w), and
b. deposit control additive formulation of claim 2 ranging from
0.01 to 0.1 w/w% (w/w)
7. A composition of claim 6 wherein gasoline fuel selected from a group consisting of octane 88, octane 91, octane 95, octane 96 and like fuels.
8. A composition of claim 6 wherein gasoline fuel may further comprise of alcohol up to 10 w/w% of the fuel.
9. A fuel composition of claim 6 wherein the concentration of deposit control additive formulation ranges from 100 to 1000 mg/lt having excellent performance in intake deposit test, PFI test, corrosion test as per ASTM D 665A carried out at room temperature, ASTM D 1094 Test of water reaction and the doped fuel meets the IS 2796:2000 specification of Indian gasoline fuel.
10. A process for the preparation of fuel composition as claimed in claim 6, said process comprising steps of:
a. obtaining deposit control additive formulation of claim 2 by
mixing mannich base, polyisobutylene amine, fluidizer oil,
dehazer, solvent and corrosion inhibitor in a suitable container
at a temperature ranging between 50°C to 60°C for a time period
of up to 2 hours, and
b. mixing at an ambient temperature the deposit control additive
formulation of step (a) with gasoline fuel to obtain fuel
composition
11. A deposit control additive composition, deposit control additive
formulation, fuel' composition and its process thereof as substantially
described with reference to examples.