JPH04226598A - Automotive fuel with improved properties - Google Patents

Abstract

PURPOSE: To obtain a motor fuel, which contains a specified amount of a specified cyclopentadienyl manganese tricarbonyl compound and reduces volatile hydrocarbon during storage and oiling and CO and NO_x while a car is running.

CONSTITUTION: The fuel composition having a Reid vapor pressure (ASTM test method D323) of 8.5 psi (58.6 kpa) or less [preferably 8.0 psi (55.2 kpa) or less] which contains up to 1/32 g of manganese per gallon (0.008 g/liter) as a fuel-soluble cyclopentadienyl manganese tricarbonyl compound.

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION This invention relates to gasoline fuel compositions with excellent environmental and usage properties.

As is well known, the light parts of gasoline tend to evaporate into the atmosphere, especially on warm or hot days, and these light parts can be removed to reduce air pollution. If you try to reduce it, the octane number will drop. Aromatic hydrocarbon gasoline component with high octane number,
For example, the proportions of benzene, toluene and xylene can be increased to compensate for the decrease in octane number. However, since aromatics are particularly undesirable in terms of toxicity, it would be desirable to provide a method for reducing the volatility of gasoline in the final stage without increasing the aromatics content.

The gasoline fuel composition of the present invention is manufactured by Reid (R
eid) vapor pressure (ASTM test method D-323) of 8.
5psi (58.6kPa) or less, preferably 8.0p
si (55.2 kPa) and up to 1/32 g (0.2 g) per gallon of cyclopentadienyl manganese tricarbonyl compound soluble in at least one fuel.
0.008 g/liter) of manganese. Using cyclopentadienyl manganese tricarbonyl,
The octane number of gasoline with low laid vapor pressure is increased without increasing volatility or increasing aromatics content. It has also been found that these manganese compounds tend to have a greater octane improving effect on paraffinic and naphthenic hydrocarbons than on the aromatic hydrocarbons of gasoline. Furthermore, the use of the fuel of the present invention reduces carbon dioxide and nitrogen oxide (NOx) emissions during engine operation, with little effect on the amount of hydrocarbon emissions into the exhaust pipe. The fuels of the present invention also have substantially no adverse effect on exhaust gas catalysts and oxygen sensors of the type commonly used in modern automobiles. Therefore, the fuel of the present invention is
It is an environmentally friendly fuel.

In another embodiment of the present invention, (1)
The boiling point range of gasoline [typically 70-440°F (2
1.1 to 226.7°C)] by blending suitable hydrocarbons with each other in suitable proportions to make gasoline;
and/or (2) the method of refueling and/or consuming gasoline in a motor vehicle is improved.

In the improved method for producing gasoline of the present invention, the above-mentioned cyclopentadienylmanganese tricarbonyl-containing fuel having a low laid vapor pressure is prepared by any suitable method, such as (a) during the gasoline blending process. or (b) subsequently adding a fuel-soluble additive to the gasoline; or (b) adding the additive to one or more gasoline hydrocarbon feed streams or other formulation components, such as oxygen, before blending the feed stream. It is blended by blending it with the contained fuel blending components. storing the high octane gasoline thus obtained in at least one storage tank at a storage base as required before distributing the fuel to vehicles for use;
This can then be distributed to each vehicle.

[0006] Such an improved method reduces the amount of volatile hydrocarbons released into the atmosphere during storage and/or refueling a motor vehicle and reduces the amount of volatile hydrocarbons released into the atmosphere. When the vehicle is running, less carbon monoxide and nitrogen oxide are emitted into the atmosphere than when using corresponding fuels that do not contain carbon monoxide and nitrogen oxides.

As explained above, the unleaded gasoline used in the process of the present invention has a Reid vapor pressure of 8.5 psi (5 psi).
8.6 kPa) or less, preferably 8.0 psi (55.
2kPa) or less. Reid vapor pressure, as is known, is determined at 100°F (37.8°C). Although such gasoline contains trace amounts of lead as an impurity, it is unleaded in the sense that no organic lead anti-knock agents are blended into the fuel. The hydrocarbon gasoline base stocks used to make the gasoline formulations may include direct distilled stocks, light naphtha fractions, cracked gasoline stocks obtained by thermal or catalytic cracking, hydrocracking or similar processes, modified products obtained by catalytic modification or similar methods;
Polymerized gasoline obtained by polymerization of olefins, alkylates obtained by adding olefins to isobutane or other hydrocarbons obtained by alkylation methods, isomerization of lower linear paraffins such as n-hexane, n-heptane, etc. and other hydrocarbons in the boiling range of gasoline obtained by suitable petroleum refining processes. If desired, suitable hydrocarbons obtained by other processes, such as during coal or shale mining, may be included in suitable amounts. For example, Fischer-Tropsch
Modified products based on liquid fuels obtained by the process can be included in the formulation. In all cases, the resulting gasoline must meet the Reid vapor pressure requirements of the invention and have distillation characteristics typical of conventional unleaded regular, medium, premium or super premium gasoline. These motor gasolines therefore fall within the parameters of ASTM D48414 and typically have an initial boiling point of 70-115°F (21.4-46.1°C) as measured by the Standard ASTM Distillation Test Method (ASTMD86). ) with a final boiling point of 370-440°F (187.8-226.7
℃). The hydrocarbon composition of gasoline in terms of volume percentages of saturates, olefins, and aromatics is typically determined by ASTM test method D1319.

[0008] Substrate gasoline is generally a blend of feedstocks obtained from various refining processes. The final formulation may also contain hydrocarbons obtained by other methods, such as alkylates obtained by reacting C4 olefins with butane using acid catalysts such as sulfuric or hydrofluoric acid, and from reforming steps. The obtained aromatic compound may be included.

The saturated gasoline component consists of paraffins and naphthenes. These saturated compounds are generally (1
) new gasoline obtained by distillation (directly distilled gasoline),
(2) alkylation step (alkylate), and (3)
Obtained from an isomerization process (isomerization of normal paraffins to branched paraffins with higher octane numbers). Saturated gasoline components are also obtained as so-called natural gasoline. In addition to these, pyrolysis gasoline, catalytic cracking gasoline and catalytic reforming products contain some amount of saturated components.

[0010] Olefin gasoline components are usually produced using thermal cracking and catalytic cracking methods. The process of dehydrogenating paraffins to olefins can supplement the gaseous olefins produced in refineries and serve as feed oil to polymerization or alkylation processes.

Gasoline base stock oil formulations incorporating the cyclopentadienylmanganese tricarbonyl additive according to the present invention generally contain 40 to 80 volume percent saturates, 1 to 30 volume percent olefins, and up to 45 volume percent aromatics. Contains %. Preferred gasoline base stock formulations for use in the present invention contain no more than 40% aromatics, preferably no more than 30%, more preferably no more than 28%, and most preferably no more than 25% aromatics. . Preferably the entire fuel formulation contains less than 1% by volume benzene, most preferably less than 0.8% by volume.

Particularly preferred unleaded gasolines made and/or used in accordance with the present invention not only meet the Reid vapor pressure criteria set forth above, but also (1) have a maximum sulfur content of 3.
00 ppm, (2) the maximum number of bromine is 20,
(3) The maximum content of aromatic compounds is 20% by volume, and (
4) a maximum content of benzene of 1% by volume; (5) a minimum content of at least one oxygenate in the form of a monoether or polyether of 1% by weight; contains up to 1/32 g of dissolved manganese per gallon (3.8 liters) as methylcyclopentadienylmanganese tricarbonyl. This type of gasoline without manganese additives is often referred to as reformate gasoline. For example, Oil & Gas Journal
Journal, April 9, 1990, pages 43-48.

From an octane number standpoint, preferred gasoline base stock oil formulations are those with an octane number expressed as (R+M)/2 from 78 to 95.

Various cyclopentadienylmanganese tricarbonyl compounds, such as those described in US Pat. No. 2,818,41
Any of the compounds listed in No. 7 can be used in the present invention. Examples of these manganese compounds include cyclopentadienyl, methylcyclopentadienyl, dimethylcyclopentadienyl, trimethylcyclopentadienyl, tetramethylcyclopentadienyl, pentamethylcyclopentadienyl, ethylcyclopentadienyl , diethylcyclopentadienyl, propylcyclopentadienyl, isopropylcyclopentadienyl, t-butylcyclopentadienyl, octylcyclopentadienyl, dodecylcyclopentadienyl, ethylmethylcyclopentadienyl manganese tricarbonyl, and Included are indenylmanganese tricarbonyl, and mixtures of two or more of these compounds. Generally speaking, suitable compounds or mixtures of compounds are those which are liquid at normal ambient temperatures, such as methylcyclopentadienylmanganesetricarbonyl, ethylcyclopentadienylmanganesetricarbonyl, cyclopentadienylmanganesetricarbonyl and methylcyclopentadienylmanganesetricarbonyl, and a mixture of methylcyclopentadienylmanganesetricarbonyl and ethylcyclopentadienylmanganesetricarbonyl. The most suitable compound is methylcyclopentadienylmanganese tricarbonyl because it is commercially available and has an excellent combination of properties and effects.

The following examples illustrate the invention and its various embodiments. In these examples, the proportions of gasoline hydrocarbons are by volume unless otherwise specified. These examples are not intended to limit the invention.

[0016]

[Example] Example 1 All saturated hydrocarbons with boiling point range of gasoline 58.9
%, 17.5% olefinic hydrocarbons and 23.6% aromatic hydrocarbons. The Reid vapor pressure of this formulation is 8.5 psi (5
8.6 kPa). This substrate fuel contains methylcyclopentadienylmanganese tricarbonyl as manganese at 1/32g (0.008g/liter) per gallon.
and 4-methyl-2,6-di-t-
Butylphenol was formulated at a concentration of 7.5 pounds per 1000 barrels (21.4 g/m3). After storing this automotive gasoline on water in open-air storage tanks at a storage station, the product was transported by gasoline transport vehicle to a gas station where it refueled cars on demand. A car consumes this gasoline while driving.

Example 2 All saturated hydrocarbons with a boiling point range of gasoline 56.9
%, 20.0% olefinic hydrocarbons and 23.1% aromatic hydrocarbons. The ingredients have a Reid vapor pressure of 8.4.
psi (57.9 kPa). 2,6-
A t-butyl phenol antioxidant mixture containing 85% di-t-butyl phenol by weight was added at a concentration of 6.5 lbs.
Blend into fuel at 1000 barrels (18.5 g/m3). In the resulting fuel, 1/32 g (1/32 g) of methylcyclopentadienylmanganese tricarbonyl per gallon (
0.008 g/liter). This fuel was stored, transported, refueled and used to drive cars. Most of these cars had catalytic converters.

Example 3 Unleaded automobile gasoline with a Reid vapor pressure of 8.0 (67.7% saturated, 7.5% olefin, 24% aromatic).
8%), the resulting fuel is 1/32g per gallon (
Methylcyclopentadienylmanganese tricarbonyl and t-butyl ether are blended in amounts such that the mixture contains 0.008 g/liter of manganese and 2.7% by weight of oxygen as t-butyl ether. The finished fuel, which can and preferably contains conventional amounts of antioxidants, metal deactivators, and carburetor cleaners, can be used to fuel passenger cars, buses, trucks, and boxcars. and can be used for driving motorcycles.

EXAMPLE 4 Examples 1-3 were repeated, except that in some cases the respective motor fuels were reduced to 1/40 g (0.007 g/gallon).
g/liter) of manganese, in another case 1/50 g/gallon (0.005 g/liter), in a third case 1/64 g/gallon
(0.004 g/liter) and in other cases 1/100 g (0.003 g/liter) of manganese per gallon.
g/liter) of manganese.

Example 5 Examples 1 to 4 were repeated, but in each case instead of methylcyclopentadienylmanganesetricarbonyl, the same concentration of manganese was added as cyclopentadienylmanganesetricarbonyl.

EXAMPLE 6 Examples 1-4 were repeated, but in one series of experiments, each fuel contained 90% by weight of methylcyclopentadienylmanganesetricarbonyl and 10% by weight of methylcyclopentadienylmanganesetricarbonyl. % by weight of cyclopentadienylmanganese tricarbonyl,
Each fuel was added in an amount such that it contained the same concentration of manganese as the fuels of Examples 1-4. In other series, Examples 1-
Each of the fuels of No. 4 contained dimethylcyclopentadienylmanganese tricarbonyl instead of methylcyclopentadienylmanganese tricarbonyl at the same manganese concentration. In yet another series, the specific manganese concentration of the fuels of Examples 1-4 was provided by t-butylcyclopentadienylmanganese tricarbonyl. In yet another series, indenylmanganese tricarbonyl was substituted for methylcyclopentadienylmanganese tricarbonyl as the manganese additive used to make automotive fuel compositions.

Example 7 Contains 40.1% saturates, 15.3% olefins, 44.6% aromatics, Reid vapor pressure 8.3 psi
(57.2 kPa) The following components were blended into unleaded gasoline.

Phenol mixture consisting of 75% 2,6-di-t-butylphenol, 10-15% 2-t-butylphenol, and 10-15% 2,4,6-tri-t-butylphenol 5 lbs. /1000 barrels (14.3g/m3) N,N'-disalicylidene-
1,2-propanediamine 1 pound/1000 barrels (2.9 g/m3) was then blended with methylcyclopentadienylmanganese tricarbonyl at a concentration equivalent to 1/32 g of manganese (0.008/liter) per gallon. .

Example 8 72.5% saturates, 4.0% olefins and 2
3.5% aromatics (of which benzene is less than 3% by volume, so the fuel contains less than 1% by volume benzene) to a Reid vapor pressure of 7.8 psi (53.8% by volume).
(kPa) unleaded gasoline for automobiles. Sufficient methyl t-butyl ether is included to provide an oxygen content of 2.0% by weight in the fuel. The resulting automobile fuel was then doped with 1/35 g of manganese (0.0
Methylcyclopentadienylmanganese tricarbonyl was blended at a concentration corresponding to 0.08/liter).

Example 9 Example 8 was repeated except that (a) the initial gasoline formulation had a Reid vapor pressure of 7.9 psi (54.5 kPa), 75.7% saturates, and 4.8% olefins; and 19.5% aromatic components (3.5% by volume of the aromatic components is benzene); (b) a mixture of methyl t-butyl ether and ethyl t-butyl ether is It was incorporated into gasoline at a concentration equivalent to 2.5% by weight.

Example 10 Example 8 was repeated except that (a) the initial gasoline formulation had a Reid vapor pressure of 7.7 psi (53.1 kPa), 78.6% saturates, and 4.4% olefins; and aromatic components (again, the benzene content of the total fuel formulation is less than 1% by volume), (b
) In place of methyl t-butyl ether, t-amyl ether was blended into gasoline at a concentration corresponding to an oxygen content of 2.7% by weight in the fuel.

Example 11 Oronite was added to each of the fuels of Examples 7-10 at a typical concentration of 100 lbs/1000 barrels (285.3 g/m3).
Oronite Chemical
Co. A polyetheramine precipitation inhibitor commercially available as OGA-480 manufactured by ) was blended.

Example 12 Each of the fuels of Examples 7-10 was injected into Ethyl Petroleum Additives at a typical concentration of 100 lb/1000 barrels (285.3 g/m3).
oleum Additives, Ltd. A polyalkenyl succinimide precipitation inhibitor commercially available as HITEC 4450 additive manufactured by Co., Ltd.) was blended.

EXAMPLE 13 Oronite was added to each of the fuels of Examples 7-10 at a typical concentration of 100 lbs/1000 barrels (285.3 g/m3).
A polyisobutenylamine precipitation inhibitor commercially available as OGA-472 manufactured by Chemical Co., Ltd. was blended.

As can be seen from the above examples, the fuel of the present invention can, and preferably does, contain additives in addition to cyclopentadienylmanganese tricarbonyl. Such other additives include antioxidants, precipitation inhibitors (also called derivatized detergent additives or fuel detergents), and oxygen-containing substances such as dialkyl ethers. All materials must not, due to their volatility, increase the vapor pressure of the fuel beyond the Reid vapor pressure limit required by the present invention. Other additives used include auxiliary anti-knock agents, such as aromatic amine anti-knock agents such as N-methylaniline, iron-based anti-knock agents such as ferrocene, methylferrocene and butadiene iron carbonyl. , nickel-based anti-knock agents such as cyclopentadienyl nickel nitrosyl. Corrosion inhibitors, metal deactivators, emulsification inhibitors and dyes are also other types of additives that can be used.

Suitable oxygen-containing substances which can and are preferably incorporated into the fuels of the present invention are suitable low volatility ethers such as methyl t-butyl ether, ethyl t-butyl ether, t-amyl methyl ether, and 2,2-diethyl-1,3-propanediol. Also useful are fuel-soluble esters and alcohols of suitable low volatility, such as t-butyl acetate, 1-hexanol, 2-hexanol, 3-hexanol, and polyethoxyethanol. Typically, such oxygen-containing compounds may be present in the fuel at a maximum of 3-4% by weight unless they conflict with existing or proposed regulations.
used in amounts sufficient to provide oxygen. Other suitable oxygen-containing agents include p-cresol, 2,4-xylene, 3-methoxyphenol, 2-methylfuran, cyclopentanone, isovaleraldehyde, 2,4-pentanedione, and similar oxygen Contains compounds.

Suitable antioxidants for the fuels of the invention are sterically hindered phenolic antioxidants, such as 2,
6-di-t-butylphenol, 2,4-dimethyl-6
-t-butylphenol, 4-methyl-2,6-di-t
-butylphenol, 4-ethyl-2,6-di-t-butylphenol, 4-butyl-2,6-di-t-butylphenol, and a mixture of t-butylphenol consisting primarily of 2,6-di-t-butylphenol. be. It has been found to be advantageous in some cases to use aromatic amine antioxidants alone or in combination with phenolic antioxidants. Antioxidants are typically used in amounts up to 25 pounds per 1000 barrels (71.3 g/m@3), depending on the stability (eg, olefin content) of the gasoline in any given case.

Other types of additives suitable for use in the fuels of this invention include ashless detergents such as polyether amines, polyalkenyl amines, alkenyl succinimides, polyether amido amines, and the like. Such additives can range from 50 to 500 pounds per 1000 barrels.
．． 6-1426.4 g/m3), especially 100-200 lbs/1000 barrels (285.3-570.6 g/m3)
It can be used with the throughput of 3).

The cyclopentadienylmanganese tricarbonyl compound as well as other auxiliary additives or ingredients can be mixed with the base fuel by known methods using conventional mixing equipment. The invention is intended to include all fuels that meet the primary requirements of the invention.

A total of 3,000,000 test miles (4
．． Driving tests were carried out on 48 motor vehicles for distances greater than 8 x 106 km). Half of the cars in each model group were run on "clean" (ie, no manganese additive) test fuel. The other half contains 1/32 g of manganese per gallon (0.008 g/liter) as methylcyclopentadienylmanganese tricarbonyl in the same fuel.
It was run using the same fuel. Test data regarding substrate fuels is shown in the table below.

[0036]

[Table 1]
table
HOWELL EEE test fuel



AST
M Certified Fuel Standard Typical

Test Method Minimum Maximum
Properties Specific gravity, API
D1298
59.2 Reid Vapor Pressure, psi D 323
8.7 9.2 9.2
Sulfur, weight% D3
120 0.20
0.001 lead, g/gal
D3237 0.0
0.05 0.001 Phosphorus,
g/gallon D3120
0.20
Nil Distillation Characteristics, °F
D 86 IBP
75
95 92 10
%
120 135 1
28 50%
200 23
0 218 95%
30
0 325 313
the last stop
415
373 Composition of hydrocarbons
D1319 Saturated component, volume %

66.5 Olefin, volume %
10 1.8
Aromatic, volume %
35
31.7 Dissolved rubber, mg/100ml
D381
0.8 Copper extraction corrosion
D130
1
Test octane number D2699
93.0
96.8 motor octane number
D2700
88.5 The motor vehicle range is 75,000 miles (12
0,701 km), the conversion efficiency of the catalyst, i.e., the automotive catalyst converts hydrocarbons (HC), carbon monoxide (CO
) and nitric oxide (NOx) emission controlled substances to non-regulated substances. Compared to the conversion efficiency of the catalyst performed on the "clean" test fuel, the conversion efficiency on the manganese-containing fuel was essentially the same for HC and about 1.1 percentage points better for CO. NOx
It was found that the results were 3.3 percentage points better than the average price.

0037: 50,000 miles (80,467km)
After driving, the behavior of the oxygen sensor was tested. For each model, the oxygen sensor was removed from the car and tested individually. There was virtually no difference in oxygen sensor behavior between cars running on clean fuel and cars running on fuel containing manganese additives.

75,000 miles (120,701km)
) Tested whether catalyst clogging occurred at the end of the run. This was done by measuring the pressure before the exhaust gas entered the catalyst system. There was no evidence of catalyst blockage in any of the cars.

[0039] Although the substrate fuel used in the above test does not contain any description of the required conditions regarding the Reid vapor pressure of the present invention, according to the results of the above test, cyclopentadienylmanganese tricarbonyl has a It has been shown that when used in high concentrations, it does not clog the catalyst or degrade the behavior of the vehicle's exhaust system. Therefore, by reducing the Reid vapor pressure to the value specified in the present invention, all the above advantages can be achieved, and at the same time the extent to which light gasoline evaporates into the atmosphere during storage, transportation and fuel consumption processes can be reduced. .

The main features and aspects of the present invention are as follows. 1. Reid Vapor Pressure (ASTM Test Method D-323) of 8.5 psi (58.6 kPa) or less and up to 1/32 per gallon of at least one cyclopentadienylmanganese tricarbonyl compound soluble in the fuel.
g (0.008 g/liter) of manganese.

2. Raid vapor pressure of gasoline is 8.0 ps
i (55.2 kPa) or less, the composition according to item 1 above.

3. 3. The composition according to item 1 or 2 above, wherein the at least one cyclopentadienylmanganese tricarbonyl compound soluble in the fuel is substantially methylcyclopentadienylmanganese tricarbonyl.

4. The substrate gasoline contains 25 aromatic hydrocarbons.
The composition according to item 1, 2 or 3 above, wherein the composition contains benzene in an amount of less than 1% by volume.

5. Substrate gasoline is at least 50% by volume
5. The composition according to any one of items 1 to 4 above, comprising a saturated hydrocarbon component.

6. 6. The composition of any of the preceding clauses, further comprising up to about 4% by weight oxygen as at least one oxygen-containing fuel formulation component.

7. (1) Reid vapor pressure (ASTM Test Method D-323) is 8.5 psi (58.6 kPa) or less; (2) maximum sulfur content is 300 ppm; (3) maximum bromine number is 20; (4) maximum aroma. Group component content is 20% by volume
, (5) the maximum benzene content is 1% by volume, (6) the minimum content of oxygen in the form of at least one monoether or polyether is 1% by weight, as methylcyclopentadienylmanganese tricarbonyl 1 An unleaded gasoline fuel composition containing up to 1/32 g/gallon (0.008 g/liter) of dissolved manganese.

8. In the gasoline manufacturing process, the Reid vapor pressure (ASTM test method D-323) is 8.5 psi (5
8.6 kPa) or less, and add up to 1/32 g (0.008 g/L) of manganese per gallon as at least one cyclopentadienyl manganese tricarbonyl compound soluble in the fuel. Improvement method.

9. A method of producing and distributing gasoline with a Reid vapor pressure (ASTM test method D-323) of 8.
5 psi (58.6 kPa) or less of unleaded gasoline with up to 1/32 g (0.008 g/L) of manganese per gallon as at least one cyclopentadienyl manganese tricarbonyl compound soluble in the fuel. In addition, it produces gasoline with a higher octane number,
An improved method for storing the enhanced octane gasoline in at least one storage tank at a storage station and then distributing the high octane gasoline for refueling motor vehicles.

10. At least one cyclopentadienylmanganese tricarbonyl compound that has a Reid vapor pressure (ASTM Test Method D-323) of 8.5 psi (58.6 kPa) or less and is soluble in the fuel in the method of using gasoline in a motor vehicle. up to 1/32 per gallon as
An improved method for using unleaded gasoline containing manganese (0.008 g/liter) in automobiles.

Claims (5)

[Claims] Claim 1: Reid Vapor Pressure (ASTM Test Method D-3
23) is 8.5 psi (58.6 kPa) or less,
An unleaded gasoline fuel composition comprising up to 1/32 g/gallon (0.008 g/liter) of manganese as at least one cyclopentadienylmanganese tricarbonyl compound soluble in the fuel. 2. (1) Reid vapor pressure (ASTM test method D-323) is 8.5 psi (58.6 kPa) or less, (2) maximum sulfur content is 300 ppm, (3) maximum bromine number is 20, (4) Maximum aromatic component content is 20% by volume
, (5) the maximum benzene content is 1% by volume, (6) the minimum content of oxygen in the form of at least one monoether or polyether is 1% by weight, as methylcyclopentadienylmanganese tricarbonyl 1 An unleaded gasoline fuel composition comprising up to 1/32 g/gallon (0.008 g/liter) of dissolved manganese. 3. In the gasoline production method, the Reid vapor pressure (ASTM test method D-323) is 8.5 psi (5 psi).
8.6 kPa) or less, and add up to 1/32 g (0.008 g/L) of manganese per gallon as at least one cyclopentadienyl manganese tricarbonyl compound soluble in the fuel. An improvement method characterized by: 4. A method for producing and distributing gasoline, wherein the Reid vapor pressure (ASTM Test Method D-323) is 8.
5 psi (58.6 kPa) or less of unleaded gasoline with up to 1/32 g (0.008 g/L) of manganese per gallon as at least one cyclopentadienyl manganese tricarbonyl compound soluble in the fuel. In addition, it produces gasoline with a higher octane number,
An improved method comprising storing the enhanced octane gasoline in at least one storage tank of a storage station and then distributing the high octane gasoline for refueling motor vehicles. 5. A method for using gasoline in automobiles, in which the Reid vapor pressure (ASTM test method D-323) is 8.
．． up to 1/32 g per gallon of at least one cyclopentadienylmanganese tricarbonyl compound soluble in the fuel and not more than 5 psi (58.6 kPa);
An improved method characterized in that unleaded gasoline containing (0.008 g/liter) manganese is used in a motor vehicle.