HUT63449A - Dicarboxylic acid additives usable in unleaded gasoline - Google Patents

Description

The present invention relates to dicarboxylic acids of the formula I for use as an excipient in unleaded petrol. These additives prevent exhaust valve seat wear on internal combustion engines for vehicles that have not been adapted for use with unleaded or low lead petrol.

To ensure a healthier environment, cars around the world are using unleaded petrol. Unleaded petrol began to be produced in the United States in the early 1970s. Production of unleaded petrol in Japan began in 1974 and in Europe in 1984. Since then, the proportion of lead-free products in gasoline production and consumption has been increasing rapidly. Worldwide, the direction of production and consumption is clearly moving towards the exclusive use of unleaded petrol. For example, since March 1986 only unleaded petrol has been used in Japan [Chem. Econ. and Eng. Rev., 9, 25 (1986) and Chem. Ind., 7, 750 (1986)]. In the United States, the ratio of unleaded petrol to total gasoline production in 1990 was over 90%, and in the early 1990s, a complete cessation of production of unleaded petrol was already under consideration. In terms of shifts and divergences in the composition of the car fleet and the technical capabilities of refineries, this is not as clear in Europe as it is in the overseas countries. The lead time for unleaded petrol in the market is different in each country.

In the developed countries of Europe, the variation in lead-free petrol currently accounts for about 50% of total production. The ratio of unleaded petrol to total petrol production is estimated to be at least 75% by 1995, a significant increase compared to 21.3% in 1986 and 26% in 1987 [ Oil and Gas Journal, 88, 4, 11 (1990) or Erdi and Kohl, 3, 119 (1988); Oil and Gas Journal, 85, 14, 15 (1987) and Petrole et Techniques, 38, 316 (1986)]. Since 1986, Czechoslovakia has been producing and selling unleaded petrol. In 1990, the share of unleaded petrol in total petrol production did not exceed 3%.

Since the start of production and use of unleaded petrol for cars, serious operational difficulties have been encountered; in addition, the technical limitations of refineries prevented the transition to exclusive production and use of unleaded petrol. The problem is that unleaded petrol may not always be suitable for car engines designed to use leaded petrol. If unleaded petrol car engines are fitted with unleaded petrol, the cylinder head or the entire engine will be damaged and the car will become inoperable [Bratsky

D., Oravkin J.: Production of Gasolines in the Czechoslovakia at the Turn of the Millennium; 33rd Conference on Crude Oil, Bratislava (1988); Bratsky D., Fehér P., Oravkin J., Malach V.: Development Trend in the Field of Automotive Gasolines and Their Additives, VURUP Study: Bratislava (1990); Petrole et Techniques, 60, 326 (1986); Automotive Engineering, 95, 11, 72 (1987); Hydrocarbon Processing, 68, 7, (1989); Grill R.A., Landells R.G.M .: Reduction of Lead in Gasoline and Its Effect on Valve Seat Recession: The Problem and Its Solution, 33rd International Conference on Crude Oil, Bratislava (1988)].

Essentially, these are old and new problems in car manufacturing that reappeared in the early 1990s, which were solved by the addition of anti-knock additives to gasoline at that time. The number of cars in the world threatened with unleaded petrol in 1987 was around 70 million [Automotive Engineering 95, 11, 72 (1987); Hydrocarbon Processing 68, 7, 17 (1989)].

In Czechoslovakia, the number of cars that are not suitable for running on unleaded petrol represents 70% of the total number of passenger cars, considering that in Czechoslovakia the average annual replacement of cars is only 5% of the total number of unleaded cars. the disappearance of a petrol-unfit car is unlikely before 2010 [Bratsky, D., Oravkin, J.: Production of Gasolines in the Turn of the Millennium; 33rd Conference on Crude Oil, Bratislava (1988); Bratsky, D., Fehér, P., Oravkin, J., Malach, V.: Development Trend in the Field of Automotive Gasolines and Their Additives, VURUP Study, Bratislava (1990)].

Almost all cars manufactured before 1971 belong to this type of automobile (Automotive Engineering 95, 11, 72 (1987)). On the other hand, most automotive factories, especially after 1986, produce models which are capable of running on unleaded petrol [Autozeitung 20, 67 (1989); Autozeitung 21, 66 (1989)].

Damage to unleaded petrol engines is caused by the quality of the materials used in the exhaust valve seat and engine cylinder head. If these parts are made of cast iron or other less valuable material, they will quickly wear out and wear out when using unleaded petrol. As a result, the exhaust valves are increasingly retracted into the cylinder head and the valve clearance becomes smaller. The end result of this process is imperfect closure of the combustion chamber, deterioration of compression, loss of engine performance, exhaust valve and valve seat burnout. After all, the cylinder head of the engine is damaged [Automotive Engineering 95, 11, 72 (1987); Grill R.A., Landells R.G.M .: Reduction of Lead in Gasoline and Its Effects on Valve Seat Recession: The Problem and Its Solution; 33rd International Conference on Crude Oil, Bratislava (1988)].

The use of lead-based gasoline has shown that lead not only has an anti-knock effect, but also has another important function, which is to protect against mechanical wear of the exhaust valve seat during engine operation. It is assumed that lead-containing knock-offs of horse-drawn combustion products coat the surface of the valve seat with a thin protective layer, which prevents high-temperature oxidation and wear, reduces combustion product adhesion and thus protects the valve seat from unwanted wear. .

To work around the problem detailed above, which would also allow the use of unleaded petrol, we have the following options:

a) replacing the cylinder head of these cars with a cylinder head having valves made of particularly hard metal; however, this option is technically not feasible for many types of obsolete wagons and costs are unacceptable to the consumer;

(b) adding to motor vehicle petrol an additive which is harmless to health and to the catalytic conversion of the catalyst and replaces the film-forming function of lead compounds, provided that the exhaust valve seat is adequately protected. Currently, only two additives are known on the world market for this purpose. These additives were relatively effective in many foreign car types, but we could not achieve satisfactory results in the exhaust valve seat wear on SKODA car engines, even if they used several times the manufacturer's recommended amount of additive in gasoline [Bratsky, D., White P., Oravkin J., Malach V .: Development Trend in the Field of Automotive Gasolines and Their Additives, VURUP Study, Bratislava (1990)].

In addition, it is possible to use leaded petrol for these types of car engines as long as they are in circulation. However, in this case, the production of leaded petrol cannot be stopped, which has negative consequences for the environment.

According to the present invention, the problem can be solved by using unleaded gasoline for motor vehicles containing the dicarboxylic acid derivatives of the invention as additives. The use of this additive ensures that the exhaust valve seats made of various non-hard metals, such as cast iron, are not damaged during the combustion of unleaded or low-lead gasoline. The dicarboxylic acid derivative of the present invention for use as an additive is harmless to health and does not damage the exhaust gas converting catalysts.

The dicarboxylic acid derivative useful as an additive can be represented by the general formula (I). In the formula (I), it is a divalent hydrocarbon group having from 1 to 38 carbon atoms, optionally containing nitrogen in the form of an amino group and / or an ether linkage;

R2 is a monovalent hydrocarbon group having from ₁ to 42 carbon atoms;

X is hydrogen and / or an alkali metal or alkaline earth metal atom;

Y is O or N;

a and b are zero or 1, where a and b together are 1 or more (a + b> 1);

R ₃ is hydrogen or C 1 -C 42 hydrocarbon optionally substituted with hydroxy, or a group of formula (II), (III) or (IV) wherein

R 4 is hydrogen or C 1-42 monovalent

a hydrocarbon group or a group of formula (III); * 5 is hydrogen or C 1-3 monovalent hydrocarbon; from is hydrogen or m; c is an integer from 1 to 10; d is an integer from 0 to 6; e is an integer from 1 to 50; f is an integer from 1 to 50. The dicarboxylic acids of the above general formula (I) are used in foal used as an additive for unleaded petrol

This avoids damaging the exhaust valve seat for engines that are not adapted to unleaded petrol and the use of the additive ensures trouble-free operation.

In order to facilitate the simple handling, proper viscosity of the dicarboxylic acid derivative used as an additive and thus ease of pumping, transport and application of the additive during filling, an excipient may be added to the additive. An excipient may be an organic solvent, preferably an aromatic solvent. Suitable solvents include toluene, xylene, aromatic hydrocarbons having from 9 to 13 carbon atoms, or mixtures thereof, such as heavy gasoline, the boiling fraction of heavy naphtha at 75-250 ° C or heat-treated gasoline at 5-250 ° C. domain fraction. The aromatic hydrocarbon content of these mixtures is generally above 25% by weight.

For the benefit described above, the dicarboxylic acid additive of the present invention should be added at a concentration of 0.025 to 1.1% by weight to automotive gasoline. When the additive is diluted with an excipient, i.e., an organic solvent is added to the additive, then the amount of the mixture is added to the gasoline so that its active ingredient content reaches the preferred concentration indicated above.

In order to ensure that the petrol is pumpable or to adjust the concentration of the additive, the additive may be further diluted prior to being loaded into the petrol, for this purpose gasoline or a component thereof or other hydrocarbon solvent may be used.

The additive of the invention is either added directly to the gasoline during the production of the additive in the refinery (primary addition) or the additive is added to the final gasoline product upon use or sale, such as at petrol filling stations (secondary addition). Secondary addition of the additive according to the invention is particularly useful if the petrol was originally free of additive.

The advantages and practical application of the present invention are illustrated by the following non-limiting examples.

Example 1

The Skoda 4-cylinder 1174 cm ³ explosion-proof cast iron cylinder head is tested using a fixed engine according to Table 1. 96 octane (RON) and 87 MON unleaded petrol (0.0000 g Pb / liter) and similar low RON and MON (0.013 g Pb / lier) unleaded petrol were used for the tests. During the tests, the valve clearance is checked every 6 hours and, if necessary, the valve clearance is adjusted so that it is never less than 0.2 mm. After the 36 hour test, the engine cylinder head is removed and the intake and exhaust valves removed. Check for changes in valve weight, measure valve seat retraction. The results are summarized in Tables 2 and 3. The recession values shown are values relative to the average of 4 cylinders; in addition, the maximum recession value for each valve is given. The results of the tests show that it is not possible to use unleaded or low lead gasoline in non-adapted engines.

Similar tests are carried out using unleaded petrol (0.0000 g Pb / liter) to which is added 850 ppm of the dicarboxylic acid derivative (I); in the formula

R 1 is a group of formula (n);

X is Ca ²⁺ / ² ;

Z is N;

R ₂ is hydrogen;

a = 2;

d = 2; and

R4 is a polypropenyl group having an average molecular weight of 450 g / mol.

The dicarboxylic acid derivative used in the experiments can be prepared by reacting phthalic anhydride with N-polypropenyl diethylenetriamine and then neutralizing the resulting phthalic acid derivative with calcium oxide.

The experimental results show that no valve recess could be observed in any of the valves, even if the experiment was continued for 56 hours. The mean change in exhaust valve clearance was -0.0075 mm, with a maximum recession measured of -0.04 mm.

Example 2

Long-term (300 hours) fixed engine life tests were conducted on a stationary, fixed SKODA four-cylinder engine (S 742.13) with cast iron cylinder heads; the tests were carried out according to Czech Standard CSN 30 0506. For the experiments, RON 96 octane and MON 87 unleaded gasoline (0.004 g Pb / liter) were used. 700 ppm of the additive according to the invention was added to the fuel used; the chemical structure of the additive can be represented by the general formula (I); in the formula

^R i meaning (h) general formula group; X meaning sodium; z meaning oxygen; the is 0; b is 1; ^R 3 meaning (i) general formula group in which

e is an integer from 3 to 5;

Rg is a group of formula (j) wherein f is an integer from 1 to 3.

The dicarboxylic acid derivatives of formula (I) may be prepared by reacting tetrapropenyl succinic anhydride with propoxylated tetradecylamine and then neutralizing the resulting intermediate with sodium hydroxide.

The additive composition of the present invention is dissolved in heavy gasoline before being added to unleaded automotive gasoline, thereby facilitating the handling and administration of the additive; the solution thus prepared contains 50% by weight of the active ingredient.

The results of the tests show no change in the exhaust valve. The average change in valve clearance was only 0.055 mm. By adding the above amounts of the additive of the invention to unleaded petrol, the exhaust valve seats are fully protected from the adverse effects. When running on unleaded petrol, there was no engine damage and no reduction in engine life.

Example 3

The vehicles shown in Table 4 were tested on the road; the cars being tested

We have traveled between 000 and 80,000 kilometers. The cars are fitted with a new engine, carburetor, petrol tank and intake manifold. For operation, unleaded petrol (0.001 - 0.005 g Pb / liter) of 95 to 97 RON octane was used; the gasoline contained 7-12% by volume of methyl tert-butyl ether (MTBE) and 750 ppm of the dicarboxylic acid derivative of the formula (I) according to the invention; in the general formula (I)

R1 meaning X meaning z meaning ^r 2 meaning the is 1; b is 1; R meaning

-CH = CH-;

sodium atom; N; phenyl;

formula ^C 12 ^H 25 group.

This dicarboxylic acid derivative can be prepared by reacting the corresponding secondary amine with maleic anhydride and neutralizing the resulting product with sodium hydroxide.

Prior to addition to unleaded petrol, the additive was dissolved in an aromatic solvent boiling at 140-190 ° C; this makes the handling of the additive simpler; the resulting solution is 10% by weight! contains the active ingredient.

During the investigations, the cars were mainly used in urban and highway traffic. We checked the exhaust valve clearance every 5,000 km, checked the vehicle's performance and emission characteristics every 10,000 km, and measured fuel consumption and octane requirements. In the case of catalytic converters, the efficiency of the catalyst has been determined. At the end of the experiments, the engine was removed from the car and subjected to a detailed evaluation.

The evaluation shows that the use of the inventive additive for each type of car provides complete protection of the exhaust valve seat against the damage that is commonly encountered when using unleaded petrol. The use of the additive according to the invention did not adversely affect any of the functions of the explosive engine and did not reduce engine life. The additive according to the invention does not adversely affect the purification of the exhaust system operated by the catalyst system, nor does it impair the emission image of the explosive engine.

Table 1

Conditions for testing with a fixed engine

Speed gear Period (minute) Engine speed (1 min ^-1 ) Engine load First 20 3000 complete 2. 10 850 idling 3. 20 5000 complete 4. 10 850 idling

In experiments with unleaded petrol (0.000 g Pb / l) containing no additive, the effect of the test time on the recess of the valve seat was tested. The results are summarized in Table 2.

Table 2

Hours Exhaust valve seat recession mm average of 4 cylinders Maximum value in mm for a given roller

0.26

0.35

0.45

0.60

0.80

1.19

In experiments with unleaded lead-containing gasoline (0.013 g Pb / l), the effect of test time on valve seat recession was tested.

Table 3

Hours Exhaust valve seat recession mm average of 4 cylinders Maximum value in mm for a given roller

0.12

0.23

0.32

0.54

0.43

0.76 «· · ·« *

Table 4

Type of car Number of cars SKODA 120 L 3 SKODA 130 L 8 Catalytic converter SKODA FAVORIT 136 L 4 VOLGA GAY 24.10 2 OLTCIT 11 R 3

The use of the derivatives of formula (I) according to the invention as additives to unleaded petrol enables any type of explosive engine to run on environmentally friendly unleaded petrol and thus immediately switch from production of unleaded petrol to unleaded petrol.

Claims (1)

A patent claim Dicarboxylic acid derivatives of formula (I) for use as an additive to unleaded or low-lead gasoline to prevent exhaust valve seat wear in non-leaded gasoline vehicles of formula (I) R1 is a divalent hydrocarbon group having from 1 to 38 carbon atoms, optionally containing nitrogen in the form of an amino group and / or an ether linkage; R2 is a monovalent hydrocarbon group having from ₁ to 42 carbon atoms; X is hydrogen and / or an alkali metal or alkaline earth metal atom; Y is O or N; a and b are zero or 1, where a and b together are 1 or more (a + b> 1); R ₃ is a hydrogen atom or a C 1 -C 42 hydrocarbon group optionally substituted by a hydroxy group, or a group of formula (II), (III) or (IV) wherein: R ₄ is hydrogen or from 1 to 42 carbon atoms, a monovalent hydrocarbon group or a group of formula (III); R 5 is hydrogen or C 1-3 monovalent hydrocarbon; Rg is hydrogen or m; c is 1-10 d is 0 and e is 1 and f is 1 and integer between; An integer between 6; An integer between 50; 50 is an integer. The agent shall: Danubia Patent and Trademark Office Wt