MXPA01004701A - Automotive gasoline fuel for internal combustion engines - Google Patents

Abstract

A fast burning, gasoline type composition for spark ignited internal combustion engines having a ASTM D-86, 90%distillation temperature of 310°F or less and an octane number (R+M)/2 of 82 or less that can be used with a reduced spark advance in the engines to effect a reduction in NOx exhaust emissions. Also disclosed is a gasoline having low octane (82-87) which can be used interchangeably in engines having a reduced spark advance and in engines having conventional spark advance.

Description

AUTOMOTIVE GAS FUEL FOR INTERNAL COMBUSTION ENGINES FIELD OF THE INVENTION The present invention relates to gasoline compositions and their uses in spark ignition internal combustion engines as in the type of automobile engines.

BACKGROUND OF THE INVENTION The pollutants produced by combustion include nitrogen oxides which are more commonly referred to as N0X (where x is an integer representing the number of oxygen atoms in the molecule). Such oxides include NO and N02. In the combustion process N0X is formed by air (a gas containing nitrogen and oxygen) when subjected to high temperatures for a period of time. Recent studies have been made in 90% low temperature distillation gasolines which shows that a faster burning gasoline (low 90% distillation temperature) reaches a high temperature more rapidly increasing the time in which oxygen and the air is exposed to high temperature thus causing an increase in NOx (see figure). This type of fuel is described in the Patent Ref: 129211 North American No. 5,015,356 which is incorporated herein by reference. Gasolines now used as fuel in current spark ignition internal combustion engines require octane numbers (R + M) / 2 that fall completely in the range of 84-94. Some engines require an octane gasoline higher than others depending on their compression ratio or the formation of carbon deposits (aging) in order to avoid or reduce "detonation" or to improve fuel combustion efficiency. Low octane gasolines have been used in the past in low compression engines but were abandoned in common practice due to poor efficiency and power generation. Later it was discovered that increasing the compression of the engine and advancing the ignition time improved the combustion efficiency of the fuel. However, the achievement of this result required gasoline to have a much higher octane number. In fact, the state of California now requires by law that the type of automotive gasoline produced, imported, sold or used in California have a minimum octane number (R + M) / 2 of 87. It would be very desirable if low gasoline octane could be used efficiently in current engines available especially if their use would result in the reduction of pollution by N0X. As described below, the present invention relates in part to a low octane fuel having an octane rating of less than 82 and a 90% ASTM D-86 distillation temperature of less than 154.4 ° C (310 ° F). ) (referred to here as gasoline E II). The aforementioned gasoline E II is advantageous because it is a fuel with a low octane rating which, however, can be used in conventional internal combustion engine engines only by the retardation of the advance to the ignition of the engine. Therefore, current engines are capable of providing improved combustion efficiency with gasoline having octane numbers of less than 82 provided the ignition advance is retarded and gasoline has a low distillation temperature (distillation temperature ASTM D-86). 90% lower than 154.4 ° C (310 ° F)). Using gasoline from previous techniques in engines that have a retarded ignition advance causes an increase in the combustion contaminants in such a way that the gasoline of previous techniques and the gasoline E II can not be used interchangeably in an engine that has a advance to the minor ignition. Consequently, it could be highly desirable to additionally provide a gasoline that was used efficiently in current engines without the retardation in advancing ignition as well as in engines in which the ignition advance has been retarded to accommodate the E II gasoline.

BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to provide a novel gasoline for use in spark ignition internal combustion engines that allows or results in the reduction of N0X emissions. An object of the present invention is to provide low octane automotive gasoline (less than 87) which can nevertheless be used to efficiently operate conventional automotive engines without the production of undesirable levels of contamination. More specifically, a first objective of the present invention is to provide a method for achieving the reduction of N0X by modifying the moto_r so that the fuel of the present invention can be used efficiently. In this regard, it has been found that the fuels of the present invention which have an octane number less than 82 and a 90% distillation temperature of 154. ° C (310 ° F) or less can be used, however, in conventional internal combustion automotive engines by reducing only the advance to the ignition of the engine. Such gasoline (referred to here as gasoline E II) can not be used in conventional engines where advancement to ignition has not been delayed. Therefore, a second objective of the invention is to provide low octane fuels (referred to herein as gasoline E III) which can be used interchangeably in engines with conventional ignition advancements as well as in engines in which the advance has been retarded to the ignition to accommodate the gasoline E II. A further objective of the present invention is to provide a clean burning fuel and which produces low levels of contaminants in the exhaust stream of an internal combustion engine. A further objective of the present invention is to provide a gasoline having good workability and cold start properties. Still a further objective of the present invention is to provide a gasoline that will perform well at air to fuel ratios above the stoichiometry in an internal combustion engine. It is also another object of the present invention to provide a liquid fuel which can be formed in a vaporous or gaseous state and which will still tend to remain in this state when mixed with the induction of air in an internal combustion engine.

These and other objectives are obtained with a gasoline having a low distillation temperature of 90% and a low octane number. The low 90% distillation temperature is used in such a way that gasoline can burn quickly and completely when mixed with air and ignite in an engine. The low octane number is used in such a way that the speed of combustion with air is fast. The octane number can be decreased by known techniques such as reducing the amount of high-octane components used in the production of gasoline or by reducing octane-increasing additives conventionally added to gasoline. The desired distillation temperature can be obtained by the conventional production of gasoline or refining techniques such as by distillation of heavy fractions of streams of gasoline blends in a refinery. More specifically, the first and other objectives (ie, the objectives associated with gasoline E II) are achieved by providing gasoline having an octane number of less than 82 and an ASTM D-86 distillation temperature of 90% of 154.4 ° C (310 ° F) or less. The second and other objectives (objectives associated with gasoline E III) are achieved by providing gasoline having an octane number at the upper end of less than 87 and at the lower end of 82 (ie, from 82 up to, but not including 87) and a 90% ASTM D-86 distillation temperature of 154.4 ° C (310 ° F) or less (preferably less than 143.3 ° C (290 ° F)). A common technical feature shared by all fuels of the present invention is that they all have an octane number of less than 87 and a low distillation temperature of 90%.

BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a graph showing the effects on automobile exhaust emissions when the 90% ASTM D-86 distillation temperature is reduced from 182.2 (360 ° F) to 137.8 (280 ° F).

DETAILED DESCRIPTION OF THE INVENTION 1) Gasoline E II A low boiling point gasoline reduces the "wetting of the cylinder wall", thus allowing a low "detonation" in an engine at octane levels lower than the minimum set by the state and federal regulators for a minimum octane of 87 gasoline Phase 2 modern. All the octane numbers indicated here are determined by the formula (R + M) / 2 where R is defined by the ASTM D-2600 test and M is defined by the ASTM D-2700 test. Through testing and using standard federal testing procedures, it has been discovered that such a low final boiling point can be used to operate a conventional automobile engine without detonation even though it has a lower octane number (R + M) / 2 of 82 (for example, as low as 81.8). An example of such a fuel with a 90% distillation temperature of less than 154.4 ° C (310 ° F) is the "special" gasoline of Example 1. Example 1 shows a comparison between a conventional gasoline and a gasoline of the present invention. (designated here as "SPECIAL") with a 90% ASTM D-86 distillation temperature less than 154.4 ° C (310 ° F). Previously low octane gasolines were used for low compression engines. However, it was found that by lowering the 90% distillation temperature (determined by the ASTM D-86 distillation tests) to 154.4 ° C (310 ° F) or less (preferably in the range of 122.2 ° C-_138.9 ° C (252 ° F-282 ° F), the currently available octane number could also be decreased and used in current engines that now require gasoline with an octane number of 84 or greater.The fuels of the present invention have octane ratings under 82, more preferably less than 80. In the engine dynamometer tests (example 2) it was further discovered that 90% distillation low temperature gasoline could operate a standard automotive engine at lower ignition advance than the that would be required for the same engine when burning conventional 87 octane gasoline.In addition, it was also discovered that when burning low-temperature 90% distillation gasoline in the engine with a lower ignition advance was achieved n Reduced emissions, particularly reduced NOx emissions. This is very important because normally low-temperature 90% distillation gasoline increases N0X emissions (see Figure 1) but by reducing ignition advance 'these same fuels can operate at reduced levels of N0X emissions (see example 2). The decrease in ignition advance also allows a further reduction in the octane number (R + M) / 2 to less than 81.8, preferably to 80 or less. The gasoline of the present invention uses standard components of gasoline which may include additives and / or oxygenates. Therefore, in addition to the low 90% distillation temperature and the low octane, the gasoline of the present invention is otherwise the same as conventional gasoline which is currently available. In a preferred embodiment the ASTM D-86 90% distillation temperature falls within the range of 129.4 ° C (265 ° F) to 140.5 ° C (285 ° F). In addition, the octane number of the gasoline is preferably in the range of 72-82. A gasoline of this type can reduce contaminants in an exhaust of a conventional internal combustion engine by slowing the advance to the ignition of the vehicle preferably in a range of 4 ° to 12 °. The present invention is unique in that the novel low octane gasoline described herein can be worked on currently available engines and also provides improved combustion efficiency and low levels of contaminants. of combustion compared to the use in these gasoline engines currently available. Also the gasolines of the present invention are easy to evaporate or gasify and once in the vapor or gaseous state they have an improved stability such that they essentially remain in this state when combined with the induction of air. This feature improves the ratio of gas to air and the ignition properties of combustion loads with high air to fuel ratio. The low octane of gasoline also contributes to the combustion of a high air-to-fuel ratio since excess air is an excellent octane booster. If the octane values get too high, the fuel may not have time to burn completely in the engine. It is well known that fuel combustion efficiency and low exhaust pollutants are achieved with air-to-fuel ratios greater than stoichiometric ratios. In a preferred embodiment the gasoline has a final boiling temperature (ASTM D-86) of less than 173.9 ° C 345 ° F and an octane number (R + M) / 2 of less than 80. The fuel may additionally contain additives, oxygenates , fuel diluents or other compositions which improve the properties or combustion characteristics of gasoline. Such additives can be used individually or in any of their combinations. In operation, the fuels of the present invention may be used in an internal combustion engine in the form of a liquid, vapor or gaseous state, or in any combination thereof. The use of the fuel of the present invention results in a reduction of harmful emissions from the combustion of internal combustion engines. The gasoline of the present invention also allows us to achieve a reliable ignition of combustion mixtures that contain high air-to-fuel ratios that are normally used in spark ignition internal combustion engines. 2) Gasoline E III With the exception of what is noted below, the previous description of the gasoline E II also applies to the gasolines of the present invention which can be used interchangeably in engines that have a progress ignition conventional and in engines with delayed ignition advances (petrol E III). Gasoline E III differs from gasoline E II in that it requires a particular combination of 90% distillation temperature (determined by the ASTM D-86 test) and such octane number that it can be used interchangeably in conventional engines with advances to the ignition delayed and in conventional engines with advances to the ignition conventional. It has been found that by decreasing the 90% distillation temperature (determined by the ASTM D-86 test) to 154.4 ° C (310 ° F) or less (preferably less than 143.3 ° C (290 ° F)) _ the number of Octane of prior art gasoline could also be decreased and used in current engines which now require gasoline to have an octane number of 87 or greater. In this embodiment of the invention gasoline has an octane rating in the range of 82 up to, but not including, 87. Preferably the octane range is 82-84.

In a preferred embodiment, the 90% ASTM D-86 distillation temperature is less than 143.3 ° C (290 ° F). In addition, it is this preferred embodiment that the octane number of the gasoline is in the range of 82-84. Gasoline E III is unique because it is a low octane gasoline which can be used in currently available engines with or without retarding the ignition advance and also provides improved combustion efficiency and low levels of combustion contaminants compared to the use in these gasoline engines of the previous art. In another embodiment, gasoline E III has a true boiling point end point temperature of less than 173.9 ° C (345 ° F). And an octane number (R + M) / 2 less than 84 (that is, 82 up, but not including 84).

EXAMPLE 1 The dynamic tests carried out at the Co nfliance and Research Services, Inc., of Linden, NJ, in an Oldsmobile Cutlass 1989 showed that a fuel designed for improved injection volatilization (i.e., the fuel of the present invention with a Boiling temperature at 90% below 154.4 ° C (310 ° F) designated here as SPECIAL) can perform well without detonation of the engine at a low octane. Both HC emissions (hydrocarbons) and CO increase substantially when "detonation" takes place in an engine. In this test the fuel of the invention performed well without high emissions of HC and CO, thus establishing that the engine performed well without detonation even though the fuel used had an octane rating of only 81.8.

GASOLINE * SPECIAL * Emissions HC (avg.) - .146 HC (avg.) - .136 C0 (avg.) - 1,449 C0 (avg.) - 1,431 Emissions HC (avg.) - .076 HC (avg.) - .070 Freeway CO (avg.) - .785 c0 (? Rom.) - .593 * Octane (R + M) / 2 = 92.0 ** Octane_ (R + M) / 2 = 81.8 Emissions data in grams per mile (1.6 kilometers).

EXAMPLE 2 Tests were performed at the Pittsburgh Applied Research Center (PARC) (Pittsburgh Applied Research Center) using a Pontiac 4-cylinder (2.5-liter) engine with a Go Power Dynamometer and a TEC Electromotive Control System. The following data was taken from spreadsheets of the engine operation at approximately 2,000 rpm with all conditions being approximately the same except for hydrocarbons, NOx and the fuel used by the following diagram: DATE HC NO? ADVANCE ON GASOLINE IGNITION (measured in degrees) 06/14/90 78- 1,076 49 Chevron 06/14/90 78Í 1,232 49 Chevron 06/13/90 800 960 49 Special * 06/13/90 804 968 49 Special * 06/13/90 752 556 43 Special * 06/13/90 744 596 44 Special * 06/13/90 712 368 38 Special * 06/13/90 712 328 38 Special * * less than 154.4 degrees Celsius (310 degrees F) of 90% distillation temperature. Note the change in the N0X with the variation in the ignition advance.

While the present invention has been described in terms of certain preferred embodiments and exemplified with respect to these, one skilled in the art will readily appreciate that variations, modifications, changes, omissions and substitutions can be made without departing from their essence. Therefore, it is intended that the present invention be limited only by the scope of the following claims.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (23)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. A gasoline composition for use as a fuel in a spark ignition internal combustion engine, characterized in that said fuel comprises a mixture of hydrocarbons with the condition that said gasoline has an ASTM D-86 90% distillation temperature of 154.4 ° C (310 ° F) or less and an octane number (R + M) / 2 which is less than 82.
2. 2. The fuel according to claim 1, characterized in that it has an octane value which It is 80 or less.
3. The fuel according to claim 1, characterized in that the distillation temperature at 90% is in the range of 129.4 ° C-140.5 ° C (265 ° F-285 ° F) and the octane number falls in the range of 72-82.
4. 4. A method for the operation of a spark ignition internal combustion engine having at least one combustion chamber therein and an ignition advance configuration; characterized in that said method comprises introducing gasoline and air into the at least one combustion chamber and igniting said mixture by means of a spark; said gasoline comprising a mixture of hydrocarbons with the condition that the gasoline has an ASTM D-86 distillation temperature at 90% of 154.4 ° C (310 ° F) or less and an octane number of (R + M) / 2 which is less than 82; with the proviso that said advance configuration upon ignition of said engine is set at a level at which detonation is avoided while the engine is running.
5. 5. The method of compliance with the claim 4, characterized in that said gasoline has an octane number which is 80 or less.
6. The method according to claim 4, characterized in that the gasoline has a 90% ASTM D-86 distillation temperature in the range of 129.4 ° C to 140.5 ° C (265 ° F-285 ° F) and the number of octane (R + M) / 2 falls within the range of 72-82.
7. 7. A method for reducing N0X emissions of a spark ignition internal combustion engine having at least one combustion chamber and an ignition advance configuration which is set at an effective amount to prevent detonation when gasoline has an octane rating of at least 82 and is used as a fuel to run said engine; characterized in that the improvement comprises the use of the gasoline of the invention as the fuel in the operation of the engine with the condition that the advance to the ignition is retarded by an effective amount to avoid the detonation of the engine; said gasoline comprising a mixture of hydrocarbons having at least one distillation temperature ASTM D-86 at 90% of 154.4 ° C (310 ° F) or less and an octane number (R + M) / 2 which is less than 82.
8. 8. The method according to claim 7, characterized in that the gasoline has an octane number which is 80 or less.
9. The method according to claim 7, characterized in that the gasoline has a 90% ASTM D-86 distillation temperature in the range of 129.4 ° C to 140.5 ° C (265 ° F-285 ° F) and a number of octane (R + M) / 2 falling in the range of 72-82.
10. 10. A composition of gasoline to be used in an internal combustion ignition engine? by spark, characterized in that said fuel comprises a mixture of hydrocarbons with the proviso that said mixture has a boiling end point temperature ASTM D86 of less than 173.9 ° C (345 ° F) and an octane number (R + M) / 2 less than 80 and wherein said composition may include additives and diluents of common fuels for gasoline.
11. 11. A gasoline composition for use as a fuel in an internal combustion ignition engine characterized in that said gasoline comprises a mixture of hydrocarbons with the condition that said gasoline has an ASTM D-86 distillation temperature at 90% of 154.4 ° C (310 ° F) or less and an octane number (R + M) / 2 that falls in the range of 82 up to, but not including, 87.
12. 12. The gasoline according to claim 1, characterized in that the distillation temperature at 90% is lower than 143.3 ° C (290 ° F).
13. 13. A gasoline composition for use in an internal combustion engine, characterized in that said gasoline comprises a mixture of hydrocarbons having a distillation temperature with a boiling point of true boiling point of 173.9 ° C (345 ° F) or minus and an octane number (R + M) / 2 falling in the range of 82 up to, but not including, 87.
14. 14. A method for the operation of an internal combustion engine having at least one chamber therein. combustion; characterized in that said method comprises introducing gasoline and air into at least one combustion chamber and igniting said mixture with a spark; said gasoline comprising a mixture of hydrocarbons with the proviso that said gasoline has a boiling temperature of ASTM D-86 at 90% of 154.4 ° C (310 ° F) or less and an octane number (R + M) / 2 which falls in the range of 82 up to, but not including, 87.
15. 15. The method according to claim 14, characterized in that said gasoline has a 90% distillation temperature which is less than 143.3 ° C (290 ° F) .
16. The method according to claim 14, characterized in that said gasoline comprises a mixture of hydrocarbons having a final boiling point distillation temperature of true boiling point of 173.9 ° C (345 ° F) or less and a number of octane (R + M) / 2 falling in the range of 82 up to, but not including, 87.
17. 17. The method according to the claim 14, characterized in that said motor is operated with an air to fuel ratio which is in excess to stoichiometric.
18. 18. The method according to claim 15, characterized in that said motor is operated with an air to fuel ratio which is in excess to the stoichiometric.
19. 19. The method according to claim 16, characterized in that said motor is operated with an air to fuel ratio which is in excess to stoichiometric.
20. 20. A method for reducing tailpipe emissions in automobiles, characterized in that it comprises the use of gasoline in accordance with claims 11, 12, or 13 for running automobiles driven by internal combustion engines.
21. 21. The method according to claim 20, characterized in that said gasoline includes additives, oxygenates or any diluent of the volume of gasoline.
22. 22. A method for reducing NOx emissions of a spark ignition internal combustion engine having at least one combustion chamber and an ignition advance configuration; characterized in that said method comprises introducing gasoline and air into said at least one combustion chamber and ignition mixing with a spark; said gasoline being gasoline according to claims 1, 2 or 3; with the proviso that the ignition advance setting is set at a level at which detonation is avoided while the engine is running.
23. 23. A method for reducing combustion contaminants of a spark ignition internal combustion engine, characterized in that it comprises the operation of said engine above the air to fuel stoichiometric ratios with the gasoline according to claim 11, 12 or 13