Fuel composition

Abstract

A fuel composition comprising: (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine; and (b) a polybutene polymer, wherein the polybutene polymer has a molecular weight in the range of 200 to 10,000 g / mol, more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and the polybutene polymer is present at a level of 500 to 5000 weight ppm in the fuel composition. The fuel composition of the present invention provides improved engine power and reduced combustion duration.

Description

Technical Field

[0001] The present invention relates to liquid fuel compositions, and more particularly to liquid fuel compositions that provide improved engine power and have a reduced combustion duration in internal combustion engines. The present invention also relates to a method of improving the power output, increasing the efficiency, and reducing emissions of an internal combustion engine by fueling the internal combustion engine with the liquid fuel composition described hereinbelow. The present invention also relates to a method of improving the combustion duration of a liquid fuel composition.

Background Art

[0002] In order to improve the engine efficiency, power, and acceleration characteristics of modern spark-ignition internal combustion engines, these engines are not only increasing the compression ratio but also becoming increasingly smaller and boosted.

[0003] In addition to upgrading the engine hardware, it is also possible to improve engine efficiency, reduce emissions, and increase the power and acceleration of spark-ignition engines by changing the fuel formulation used to fuel the engine. For example, gasoline fuel compositions containing specially formulated essential oil components having a high octane number and good flame speed / combustion duration characteristics can result in an increase in power and / or acceleration as well as fuel economy. However, it would be desirable to be able to use standard replacement gasoline fuels available on the market to upgrade power, acceleration, and fuel efficiency performance.

[0004] So-called high-reactivity polybutene polymers have a relatively high proportion (i.e., > 30%) of polymer molecules having terminal vinylidene groups. U.S. Patent No. 6,048,373 discloses a fuel composition containing a spark-ignition fuel, a Mannich detergent, and polybutene having a molecular weight distribution of less than 1.4 for controlling intake valve deposits and minimizing valve sticking in a spark-ignition internal combustion engine. The preferred polybutene disclosed therein has a number average molecular weight (Mn) of about 500 to about 2000, and high reactivity polyisobutylene (PIB) is disclosed. The preferred treatment rate for polybutene having a molecular weight distribution of 1.4 or less is stated to fall within the range of about 0.5 to about 50 ptb, preferably within the range of about 1.5 to about 40 ptb. The treatment rate of the high-reactivity PIB used in Example 2 was 53.2 ptb, which corresponds to about 151 ppm. However, this document does not teach the use of low molecular weight polybutene polymers at selected treatment rates to provide increased engine power and reduced combustion duration.

[0005] Surprisingly, in a gasoline fuel composition, when using low molecular weight polybutene such as low molecular weight polyisobutylene (PIB), particularly low molecular weight, high-reactivity polyisobutylene (PIB) at a selected additive treatment rate, even when standard reformulated gasoline fuel is used, it has been found that benefits can be provided with respect to improved power output (increased P max ) and reduced combustion duration. The reduction in combustion duration results in more complete combustion per cycle, which improves engine efficiency and reduces harmful emissions including particulate matter (PM / PN). SUMMARY OF THE INVENTION

[0006] According to the present invention, there is provided a fuel composition comprising (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer. A fuel composition is provided in which the polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition.

[0007] Surprisingly, the fuel composition of the present invention has been found to provide improved power output as reflected in increased P max and a reduced combustion duration of the fuel. Furthermore, the fuel composition of the present invention exhibits excellent acceleration, energy efficiency, and fuel economy.

[0008] According to another aspect of the present invention, a method of improving the power output of an internal combustion engine, the method comprising (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, supplying a liquid fuel composition comprising the same to the internal combustion engine, wherein the polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups. A method is provided.

[0009] According to another aspect of the present invention, a method of increasing the P max of an internal combustion engine, the method comprising (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, supplying a liquid fuel composition comprising the same to the internal combustion engine, The polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition, preferably, the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and a method is provided.

[0010] According to yet another aspect of the present invention, there is provided a method for reducing the combustion duration of a liquid fuel composition in an internal combustion engine, the method comprising blending a polybutene polymer with a gasoline-based fuel to form a gasoline fuel composition, wherein the polybutene polymer is blended with the gasoline-based fuel at a level of 500 to 5000 weight ppm of the gasoline fuel composition, and the polybutene has a molecular weight in the range of 200 to 10,000 g / mol, and burning the fuel composition in a spark-ignition internal combustion engine, preferably, the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups.

[0011] According to yet another aspect of the present invention, there is provided the use of a liquid fuel composition for improving the power output of an internal combustion engine, wherein the liquid fuel composition (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, and the polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition, preferably, the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups.

[0012] According to yet another aspect of the present invention, there is provided the use of a liquid fuel composition for increasing the P max of an internal combustion engine, wherein the liquid fuel composition (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) comprising a polybutene polymer, The polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and use thereof is provided.

[0013] According to yet another aspect of the present invention, there is provided the use of a polybutene polymer in a liquid fuel composition for reducing combustion duration, wherein the liquid fuel composition (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, The polybutene polymer has a number average molecular weight in the range of 200 to 10,000, the polybutene polymer is present at a level of 500 to 5000 weight ppm of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and use thereof is provided.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0015] As used herein, the term "power output" refers to the amount of resistance force required to maintain a fixed speed under wide-open throttle conditions in a chassis dynamometer test.

[0016] As used herein, the term "P max " refers to a direct measurement of the force generated by the decomposition of fuel.

[0017] According to the present invention, a method for improving the power output of an internal combustion engine is provided. Also, according to the present invention, there is a method for improving the P max of an internal combustion engine. In the context of these aspects of the present invention, the term "improving" encompasses any degree of improvement. The improvement can be, for example, 0.05% or more, preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, particularly 1% or more, even more particularly 2% or more, and still more particularly 5% or more of the power output or P max provided by a similar fuel formulation before adding low molecular weight, preferably highly reactive polybutene according to the present invention. The improvement in power output or P max can be up to 10% of the power output or P max provided by a similar fuel formulation before adding low molecular weight, preferably highly reactive polybutene according to the present invention.

[0018] Low molecular weight, preferably highly reactive polybutene can also be used to improve the acceleration of an internal combustion engine. As used herein, the term "acceleration" refers to the amount of time required for the engine to increase speed between two fixed speed states in a given gear. In the context of this aspect of the invention, the term "improve" encompasses any degree of improvement, and the power and / or P max can be improved by the same percentage as it increases upward.

[0019] According to the present invention, the power output and acceleration provided by the fuel composition can be determined by any method known to those skilled in the art, such as those taught in SAE Paper 2005-01-0239 and SAE Paper 2005-01-0244.

[0020] As used herein, the term "combustion duration" means the time (in engine crank angle) required for combustion to proceed from 10% to 90% (referred to as AI10-90 in the examples below). The term AI 50-90 is also used with respect to combustion duration and means the time (in engine crank angle) required for combustion to proceed from 50% to 90%. The investigation of combustion can be carried out by monitoring the in-cylinder pressure data. The pressure data can be collected using a piezoelectric pressure transducer capable of calculating the mass fraction burn (MFB) or combustion duration. Further information on how MFB can be calculated can be found in SAE Paper 2014-01-1336 published on April 1, 2014 by Ftwi Yohaness Hagos and Abd Rashid Abd Aziz entitled "Mass Fraction Burn Investigation of Lean Burn Low BTU Gasification Gas in Direct-injection Spark-ignition Engine".

[0021] According to the present invention, there is provided a method for reducing the combustion duration of a gasoline fuel composition, the method comprising adding a polybutene polymer to the gasoline fuel composition, the polybutene polymer being added at a level of 500 to 5000 weight ppm of the gasoline fuel composition, and the polybutene having a number average molecular weight in the range of 200 to 10,000 g / mol.

[0022] According to the present invention, the combustion duration of the fuel composition can be determined by any known method, for example, using the test methods disclosed in the Examples section below.

[0023] In the context of this aspect of the present invention, the term "reducing the combustion duration" encompasses any degree of reduction. The improvement can be, for example, 0.05% or more, preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, particularly 1% or more, even more particularly 2% or more, and still more particularly 4% or more, or 5% or more of the reduction in combustion duration provided by a similar fuel formulation prior to adding a low molecular weight, preferably highly reactive polybutene according to the present invention. The reduction in combustion duration can also be up to a 10% reduction in the combustion duration provided by a similar fuel formulation prior to adding a low molecular weight, preferably highly reactive polybutene according to the present invention.

[0024] The term "flame speed" or "laminar flame speed" (LFS) refers to the laminar burning speed. LFS is a fundamental measure of the flame propagation speed that does not complicate the mixing dynamics. However, in an engine, since the mixing dynamics play a role, the measured flame speed is referred to as the "combustion speed" and the "combustion duration". The terms "combustion speed" and "combustion duration" are also used interchangeably with "flame speed" herein. The laminar burning velocity (LBV) is a fundamental property of the chemical composition. The laminar burning velocity is defined as the speed at which the unburned gas propagates to the flame front and reacts to form products (perpendicular to the flame front under laminar conditions).

[0025] The flame speed of the fuel composition can be determined by any known method. For example, the measurement of LFS can be carried out using any one of the following three methods. 1. Stagnant flame method (up to 5 - 7 atmospheres) 2. Spherical expansion method, constant pressure or constant volume (up to 60 - 80 atmospheres) 3. Heat flux method (up to about 5 atmospheres).

[0026] All three of these methods are described in the review publication: Egolfopoulos, F.N., Hansen, N., Ju, Y., Kohse - Hoinghaus, K., Law, C.K., and Qi, F. “Advances and challenges in laminar flame experiments and implications for combustion chemistry”, Progress in Energy and Combustion Science 43 (2014) 36 - 67, https: / / doi.org / 10.1016 / j.pecs.2014.04.004.

[0027] For the following method for measuring the flame speed in a constant - volume combustion chamber (spherical bomb), see Gillespie, L.L., M.; Sheppard, C.G.; Wooley, R, Aspects of laminar and turbulent burning velocity relevant to spark ignition engines, Journal of the Society of Automotive Engineers, 2000(2000 - 01 - 0192).

[0028] The following method for measuring flame speed uses the following net pressure method: Mittal, M., Zhu, G. and Schock H., ‘Fast mass-fraction-burned calculation using the net pressure method for real-time applications’, Proc. Instn Mech Engrs, Part D: J. Automobile Engineering 223(3)(2009): 389-394.

[0029] The liquid fuel composition of the present invention comprises a base fuel suitable for use in an internal combustion engine and a low molecular weight, preferably highly reactive polybutene. Typically, the base fuel suitable for use in an internal combustion engine is gasoline or diesel fuel, and thus the liquid fuel composition of the present invention is typically a gasoline composition or a diesel fuel composition. Preferably, the base fuel is a gasoline-based fuel.

[0030] The polybutene for use herein is preferably a highly reactive polybutene. A highly reactive polybutene is a polybutene having a relatively high proportion of polymer molecules having terminal vinylidene groups, i.e., more than 30%. The term “polybutene” as used herein includes polymers made from pure or substantially pure 1-butene or isobutene, as well as polymers made from mixtures of any two or three of 1-butene, 2-butene, and isobutene, and also includes polymers containing small amounts, preferably less than 10% by weight, more preferably less than 5% by weight, of C2, C3, and C5, as well as higher olefins, and diolefins. In a preferred embodiment, the polybutene is preferably a polyisobutene (also referred to as “polyisobutylene”) in which at least 90% by weight, more preferably at least 95% by weight, of the polymer is derived from isobutene.

[0031] In a particularly preferred embodiment, the polybutene is a highly reactive polyisobutylene.

[0032] In one embodiment, the highly reactive polybutene has more than 40% of polymer molecules having terminal vinylidene groups.

[0033] In another embodiment, the highly reactive polybutene polymer has more than 50% of polymer molecules having terminal vinylidene groups.

[0034] In a preferred embodiment, the highly reactive polybutene polymer has more than 70% of polymer molecules having terminal vinylidene groups.

[0035] In another preferred embodiment, the highly reactive polybutene has more than 85% of its double bonds located at the terminal positions of the molecule.

[0036] The highly reactive polybutene polymer for use herein preferably has a molecular weight distribution of 1.5 or greater, preferably 1.6 or greater, more preferably 1.7 or greater, and even more preferably 1.8 or greater.

[0037] The polybutene polymer is present in the fuel composition at a level of 500 to 5000 weight ppm, preferably 1000 to 5000 weight ppm, more preferably 2500 to 5000 weight ppm. Examples of preferred levels of polybutene include 2500 weight ppm and 5000 weight ppm of the fuel composition.

[0038] One or more polybutene polymers can be used in the fuel compositions herein. When two or more polybutene polymers are used herein, the total level of polybutene polymers is the same as the range given in the previous paragraph.

[0039] The polybutene polymer for use herein is a low molecular weight polybutene polymer. As used herein, the term "low molecular weight polybutene" refers to a number average molecular weight (M) in the range of 200 to 10,000 g / mol, preferably 500 to 5000 g / mol, more preferably 1000 to 5000 g / mol. nmeans a polybutene polymer having n ). In another embodiment of the present invention, the polybutene for use herein has a number average molecular weight (M n ). The number average molecular weight of the polybutene polymer can be determined using gel permeation chromatography.

[0040] The highly reactive polybutene for use herein can be of biological origin or of non-biological origin. In one embodiment of the present invention, the polybutene is a low molecular weight highly reactive polyisobutylene derived from a 100% renewable feedstock.

[0041] The highly reactive polybutene for use herein preferably contains less than 1 mg / kg of chlorine.

[0042] In one embodiment, the highly reactive polybutene polymer for use herein has a kinematic viscosity at 100 °C of 190 mm 2 / s or more, preferably 190 mm 2 / s to 1500 mm 2 / s, more preferably in the range of 430 to 1500 mm 2 / s.

[0043] Preferred highly reactive polybutenes for use herein have an alpha-olefin content of more than 85%.

[0044] Suitable highly reactive polybutenes for use herein include those commercially available from BASF under the trade name Glissopal®, such as Glissopal® 1000, Glissopal® 1300, and Glissopal® 2300.

[0045] Glissopal® 1000 has a number average molecular weight (M of 1000 g / moln ) a number average molecular weight (M) of 1.6 w / M n ), an alpha olefin content of more than 85%, a kinematic viscosity at 100 °C of 190 mm 2 / s, and a chlorine content of less than 1 mg / kg.

[0046] Glissopal® 1300 has a number average molecular weight (M) of 1300 g / mol n ), a molecular weight distribution (M w / M n ) of 1.7, an alpha olefin content of more than 85%, a kinematic viscosity at 100 °C of 190 mm 2 / s, and a chlorine content of less than 1 mg / kg.

[0047] Glissopal® 2300 has a number average molecular weight (M) of 2300 n ), a molecular weight distribution (M w / M n ) of 1.6, an alpha olefin content of more than 85%, a kinematic viscosity at 100 °C of 190 mm 2 / s, and a chlorine content of less than 1 mg / kg.

[0048] Glissopal® 1000, 1300, and 2300 BMBcert™, which are low molecular weight, highly reactive polyisobutenes derived from 100% renewable feedstocks commercially available from BASF, are also suitable for use herein.

[0049] The polybutene polymer can be blended with any other additives, such as an additive performance package, to produce an additive blend. The additive blend is then added to a base fuel to produce a liquid fuel composition.

[0050] The amount of the performance package in the additive blend is preferably in the range of 0.1 to 99.8 wt%, more preferably 5 to 50 wt%, of the additive blend.

[0051] Preferably, the amount of the performance package present in the liquid fuel composition of the present invention ranges from 15 ppmw (parts per million by weight) to 10% by weight based on the total weight of the liquid fuel composition. More preferably, the amount of the performance package present in the liquid fuel composition of the present invention further coincides with one or more of the following parameters (i) to (xv): (i) At least 100 ppmw (ii) At least 200 ppmw (iii) At least 300 ppmw (iv) At least 400 ppmw (v) At least 500 ppmw (vi) At least 600 ppmw (vii) At least 700 ppmw (viii) At least 800 ppmw (ix) At least 900 ppmw (x) At least 1000 ppmw (xi) At least 2500 ppmw (xii) Maximum 5000 ppmw (xiii) Maximum 10000 ppmw (xiv) Maximum 2% by weight. (xv) Maximum 5% by weight.

[0052] In the liquid fuel composition of the present invention, when the base fuel used is gasoline, the gasoline may be any gasoline suitable for use in a spark-ignition (gasoline) type internal combustion engine known in the art, including automotive engines and other types of engines such as off-road and aviation engines. The gasoline used as the base fuel in the liquid fuel composition of the present invention may also be referred to as "base gasoline" for convenience. Gasoline may also contain various levels of bio-components and biostreams at any level while maintaining appropriate analytical specifications. The bio-components are obtained from any biomass conversion process, including variations of non-thermal biomass conversion such as non-catalytic and catalytic biomass pyrolysis, hydrothermal liquefaction, and microbial-catalyzed biochemical processes. Any biomass suitable as a feedstock for these processes is ideal.

[0053] Gasoline typically contains a mixture of hydrocarbons that boil in the range of 25 to 230 °C (EN-ISO 3405), and the optimum range and distillation curve typically vary according to climate and season. The hydrocarbons in gasoline can be derived by any means known in the art, and conveniently, the hydrocarbons can be derived by any known method from straight-run gasoline, synthetically produced aromatic hydrocarbon mixtures, pyrolyzed or catalytically cracked hydrocarbons, hydrocracked petroleum fractions, catalytically reformed hydrocarbons or mixtures thereof.

[0054] The specific distillation curve, hydrocarbon composition, research octane number (RON) and motor octane number (MON) of gasoline are not important.

[0055] Conveniently, the research octane number (RON) of gasoline may be at least 80, for example in the range of 80 to 110, preferably the RON of gasoline is at least 90, for example in the range of 90 to 110, more preferably the RON of gasoline is at least 91, for example in the range of 91 to 105, even more preferably the RON of gasoline is at least 92, for example in the range of 92 to 103, even more preferably the RON of gasoline is at least 93, for example in the range of 93 to 102, and most preferably the RON of gasoline is at least 94, for example in the range of 94 to 100 (EN 25164). The motor octane number (MON) of gasoline may conveniently be at least 70, for example in the range of 70 to 110, preferably the MON of gasoline is at least 75, for example in the range of 75 to 105, more preferably the MON of gasoline is at least 80, for example in the range of 80 to 100, and most preferably the MON of gasoline is at least 82, for example in the range of 82 to 95 (EN 25163).

[0056] Typically, gasoline contains components selected from one or more of the following groups: saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and oxygenated hydrocarbons. Conveniently, gasoline may contain a mixture of saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and optionally oxygenated hydrocarbons.

[0057] Typically, the olefinic hydrocarbon content of gasoline ranges from 0 to 40 volume % based on gasoline (ASTM D1319). Preferably, the olefinic hydrocarbon content of gasoline ranges from 0 to 30 volume % based on gasoline, and more preferably, the olefinic hydrocarbon content of gasoline ranges from 0 to 20 volume % based on gasoline.

[0058] Typically, the aromatic hydrocarbon content of gasoline is in the range of 0 to 70 volume percent based on gasoline (ASTM D1319), for example, the aromatic hydrocarbon content of gasoline is in the range of 10 to 60 volume percent based on gasoline. Preferably, the aromatic hydrocarbon content of gasoline is in the range of 0 to 50 volume percent based on gasoline, for example, the aromatic hydrocarbon content of gasoline is in the range of 10 to 50 volume percent based on gasoline.

[0059] In one embodiment of the present specification, the gasoline-based fuel contains less than 10 volume % aromatics based on the total base fuel. In another embodiment of the present specification, the gasoline-based fuel contains less than 2 volume % aromatics having 9 or more carbon atoms based on the total base fuel.

[0060] The benzene content in gasoline is at most 10 volume %, more preferably at most 5 volume %, and particularly at most 1 volume % based on gasoline.

[0061] Gasoline preferably has a low or ultra-low sulfur content, for example, at most 1000 ppmw (parts per million by weight), preferably 500 ppmw or less, more preferably 100 or less, even more preferably 50 or less, and most preferably 10 ppmw or less.

[0062] The gasoline also preferably has a low total lead content of at most 0.005 g / l, and most preferably is lead-free, i.e., no lead compounds are added (i.e., unleaded).

[0063] When the gasoline contains oxygenated hydrocarbons, at least a part of the non-oxygenated hydrocarbons is replaced by the oxygenated hydrocarbons (match blend) or simply added to the fully formulated gasoline (splash blend). The oxygenate content of the gasoline may be up to 85% by weight (EN 1601) (e.g., ethanol itself) based on the gasoline. For example, the oxygenate content of the gasoline may be up to 35% by weight, preferably up to 25% by weight, more preferably up to 10% by weight or less. Conveniently, the oxygenate concentration is selected from a minimum concentration selected from any one of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2% by weight, and a maximum concentration selected from any one of 12, 8, 7.2, 5, 4.5, 4.0, 3.5, 3.0, and 2.7% by weight.

[0064] Examples of suitable oxygenated hydrocarbons that can be incorporated into gasoline include alcohols, ethers, esters, ketones, aldehydes, carboxylic acids and their derivatives, and oxygen-containing heterocyclic compounds, and mixtures thereof. Preferably, the oxygenated hydrocarbons that can be incorporated into gasoline are selected from alcohols (such as methanol, ethanol, propanol, 2-propanol, butanol, tert-butanol, iso-butanol, and 2-butanol), ethers (preferably ethers containing 5 or more carbon atoms per molecule, such as methyl tert-butyl ether, and ethyl tert-butyl ether) and esters (preferably esters containing 5 or more carbon atoms per molecule). A particularly preferred oxygenated hydrocarbon is ethanol.

[0065] When oxygenated hydrocarbons are present in gasoline, the amount of oxygenated hydrocarbons in the gasoline can vary over a wide range. For example, gasoline containing a high proportion of oxygenated hydrocarbons, such as ethanol itself and E85, and gasoline containing a low proportion of oxygenated hydrocarbons, such as E10 and E5, are currently commercially available in countries such as Brazil and the United States. Thus, gasoline can contain up to 100% by volume of oxygenated hydrocarbons. E100 fuel as used in Brazil is also included herein. Preferably, the amount of oxygenated hydrocarbons present in the gasoline is one of the following amounts, depending on the desired final formulation of the gasoline: up to 85% by volume, up to 70% by volume, up to 65% by volume, up to 30% by volume, up to 20% by volume, up to 15% by volume, and up to 10% by volume. Conveniently, the gasoline can contain at least 0.5, 1.0 or 2.0% by volume of oxygenated hydrocarbons.

[0066] Examples of suitable gasoline include gasoline having an olefinic hydrocarbon content (ASTM D1319) of 0 to 20% by volume, an oxygen content (EN1601) of 0 to 5% by weight, an aromatic hydrocarbon content (ASTM D1319) of 0 to 50% by volume, and a benzene content of up to 1% by volume.

[0067] Gasoline blend components that can be derived from sources other than crude oil, such as low-carbon gasoline fuels from either biomass or CO2, and blends of these with each other or with fossil-derived gasoline streams and components are also suitable for use herein. Suitable examples of such fuels include the following. 1) Biomass-derived: a. Straight-run bio-naphtha from the hydrodeoxygenation of biomass, and b. Products from the cracking and / or isomerization of synthetic wax (biomass gasification to synthesis gas (CO / H2) by the Fischer-Tropsch (FT) process, then to synthetic wax), then hydrocracked / hydroisomerized to yield a slate of products including fractions in the gasoline distillation range. 2) CO2-derived: a. Modified water / gas shift reaction of CO2 + H2 syngas (CO / H2) to synthetic wax by the FT process, followed by hydrocracking / hydroisomerization to yield a slate of products including fractions in the gasoline boiling range. 3) Derived from methanol: a. Biomass gasification to syngas (CO / H2), then to methanol, then to gasoline by the MTG process (MTG is the "methanol to gasoline" process). To further reduce the carbon intensity of the fuel, the H2 used in all processes will be renewable (environmentally friendly) H2 from the electrolysis of water using renewable electricity from sources such as wind and sun.

[0068] Particularly suitable for use herein are gasoline blend components that may be derived from biological sources. Examples of such gasoline blend components can be found in International Publication No. WO 2009 / 077606, International Publication No. WO 2010 / 028206, International Publication No. WO 2010 / 000761, European Patent Application Nos. 09160983.4, 09176879.6, 09180904.6, and U.S. Patent Application No. 61 / 312307.

[0069] Although not important for the present invention, the base gasoline or gasoline composition of the present invention may advantageously contain one or more optional fuel additives in addition to low molecular weight, preferably highly reactive polybutene. The concentration and nature of the optional fuel additives that may be included in the base gasoline or gasoline composition of the present invention are not important. Non-limiting examples of suitable types of fuel additives that may be included in the base gasoline or gasoline composition of the present invention include antioxidants, corrosion inhibitors, detergents, cloud point depressants, antiknock additives, metal deactivators, valve-seat recession protectant compounds, dyes, solvents, dispersants, diluents, and markers. Examples of suitable such additives are generally described in U.S. Patent No. 5,855,629.

[0070] Conveniently, the fuel additive can be blended with one or more solvents to form an additive concentrate, which can then be admixed with the base gasoline or gasoline composition of the present invention.

[0071] The concentration of any optional additive present in the base gasoline or gasoline composition of the present invention (active substance) is preferably at most 1% by weight, more preferably in the range of 5 - 2000 ppmw, advantageously in the range of 300 - 1500 ppmw, for example 300 - 1000 ppmw.

[0072] Further conventional additives for use in gasoline are, for example, ammonium salts of organic carboxylic acids, provided that the salt has a tendency to form a film, ammonium salts, or corrosion inhibitors based on heterocyclic aromatic ammonium salts for the protection against non-ferrous metal corrosion; cloud point depressants; anti-knock additives; metal deactivators; solvents; carrier fluids; diluents; amines such as phenylenediamines, for example p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, dicyclohexylamine, or their derivatives, or antioxidants or stabilizers based on derivatives of phenols such as 2,4-di-tert-butylphenol or 3,5-di-tert-butyl-4-hydroxy-phenylpropionic acid; antistatic agents; metallocenes such as ferrocene; methyl-cyclopentadienyltricarbonylmanganese; lubricity additives such as certain fatty acids, alkenyl succinic esters, bis(hydroxyalkyl) fatty amines, hydroxyacetamides, or castor oil; and dyes (markers). Suitable such additives are disclosed in U.S. Patent No. 5,855,629. If appropriate, amines may be added, for example, as described in WO 03 / 076554. Optionally, anti-valve seat recession additives such as sodium or potassium salts of polymeric organic acids may be used.

[0073] The gasoline composition of the present specification may also contain a detergent additive. Preferred detergent additives include those disclosed in International Publication No. WO 2009 / 50287, which is incorporated herein by reference.

[0074] A detergent additive preferably used in the gasoline composition of the present specification typically has at least one hydrophobic hydrocarbon group having a number average molecular weight (Mn) of 85 to 20,000, and (A1) a mono- or polyamino group having up to 6 nitrogen atoms, at least one of which is basic, (A6) a polyoxy-C 2- ~C4-alkylene group terminated by a hydroxyl group, a mono- or polyamino group in which at least one nitrogen atom has basic properties, or a carbamate group, (A8) a moiety derived from succinic anhydride and having a hydroxyl group and / or an amino group and / or an amide group and / or an imide group, and / or (A9) at least one polar moiety selected from moieties obtained by a Mannich reaction of a substituted phenol with an aldehyde and a mono- or polyamine.

[0075] To ensure proper solubility in the base fluid, the hydrophobic hydrocarbon group in the above detergent additive has a number average molecular weight (Mn) of 85 to 20,000, particularly 113 to 10,000, particularly 300 to 5,000. Typical hydrophobic hydrocarbon radicals particularly related to the polar moieties (A1), (A8), and (A9) include polyalkenes (polyolefins), for example, polypropenyl, polybutenyl, and polyisobutenyl radicals each having an Mn of 300 to 5,000, preferably 500 to 2,500, more preferably 700 to 2,300, particularly 700 to 1,000.

[0076] Non-limiting examples of the above groups of the detergent additive include the following.

[0077] Additives containing a mono- or polyamino group (A1) are preferably polyalkene monoamines or polyalkene polyamines based on polypropylene having an Mn of 300 to 5000 or conventional (i.e., mainly having internal double bonds) polybutene or polyisobutene. When polybutene or polyisobutene mainly having internal double bonds (usually at the β and γ positions) is used as the starting material in the preparation of the additive, the possible preparation routes are by chlorination and subsequent amination, or by formation of a carbonyl compound or carboxyl compound by oxidation of the double bond with air or ozone and subsequent amination under reduction (hydrogenation) conditions. The amines used here for amination can be, for example, ammonia, monoamines, or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, or tetraethylenepentamine. The corresponding additives based on polypropylene are described in particular in WO 94 / 24231 (A).

[0078] More preferred additives containing a monoamino group (A1) are hydrogenation products of reaction products of polyisobutene having an average degree of polymerization of 5 to 100 with nitrogen oxides or a mixture of nitrogen oxides and oxygen, as described in particular in WO 97 / 03946 (A).

[0079] More preferred additives containing a monoamino group (A1) are compounds obtained from polyisobutene epoxide by reaction with an amine and subsequent dehydration and reduction of the amino alcohol, as described in particular in DE 196 20 262 (A).

[0080] Additives containing a polyoxy-C2-C4-alkylene moiety (A6) are preferably C2-~C 60 -alkanols, C6-~C 30 -alkanediols, mono- or di-C2-C 30 -alkylamines, C1-C 30 -alkylcyclohexanols, or C1-C 30- Polyethers or polyetheramines obtained by reaction of an alkylphenol with 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl or amino group, and in the case of polyetheramines, by subsequent reductive amination with ammonia, a monoamine, or a polyamine. Such products are described, in particular, in European Patent No. 310 875 (A), European Patent No. 356 725 (A), European Patent No. 700 985 (A), and U.S. Patent No. 4 877 416 (A). In the case of polyethers, such products also have carrier oil properties. Typical examples of these are tridecanol butoxylate, isotridecanol butoxylate, isononylphenol butoxylate, and polyisobutene butoxylate, and polyisobutene propoxylate, and the reaction products with the corresponding ammonia.

[0081] Additives (A8) derived from succinic anhydride and containing moieties having hydroxyl and / or amino and / or amide and / or imide groups are preferably corresponding derivatives of polyisobutenyl succinic anhydride obtained by reacting a conventional polyisobutene or highly reactive polyisobutene having an Mn of 300 to 5000 with maleic anhydride by a thermal route or via chlorinated polyisobutene. Of particular interest are derivatives having aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, or tetraethylenepentamine. Such additives are described, in particular, in U.S. Patent No. 4 849 572 (A).

[0082] The additive (A9) containing a moiety obtained by the Mannich reaction of a substituted phenol with an aldehyde and a mono- or polyamine is preferably a reaction product of a polyisobutene-substituted phenol with formaldehyde and a mono- or polyamine, such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, or dimethylaminopropylamine. The polyisobutenyl-substituted phenol can be derived from a conventional polyisobutene or a highly reactive polyisobutene having an Mn of 300 to 5000. Such "polyisobutene-Mannich bases" are described in particular in European Patent No. 831 141 (A).

[0083] Preferably, the detergent additive used in the gasoline composition of the present invention contains at least one nitrogen-containing detergent, more preferably at least one nitrogen-containing detergent containing a hydrophobic hydrocarbon group having a number average molecular weight in the range of 300 to 5000. Preferably, the nitrogen-containing detergent is selected from the group consisting of polyalkene monoamines, polyetheramines, polyalkene Mannich amines, and polyalkene succinimides. Conveniently, the nitrogen-containing detergent can be a polyalkene monoamine.

[0084] In the above, the amounts (concentration, volume%, ppmw, weight%) of the components are those of the active substances, i.e., excluding volatile solvent / diluent materials.

[0085] The liquid fuel composition of the present invention can be produced by mixing an essential low molecular weight, preferably highly reactive polybutene, with a gasoline-based fuel suitable for use in an internal combustion engine. Since the base fuel with which the essential fuel additive is admixed is gasoline, the resulting liquid fuel composition is a gasoline composition.

[0086] Surprisingly, the use of a combination of low molecular weight, preferably highly reactive polybutene having a number average molecular weight of 500 to 10,000 g / mol and present in an amount of 500 to 5000 weight ppm of the fuel composition provides improved power and increased P of an internal combustion engine fueled by a liquid fuel composition containing said polybutene compared to an internal combustion engine fueled by a liquid-based fuel. max has been found to provide benefits with respect to P. In a preferred embodiment of the present specification, the improvement in power can be observed under low load and low speed conditions (such as 1300 rpm and 11.5 bar) and high load and high speed conditions (such as 3300 rpm and 12.4 bar). Highly reactive polyisobutylene polymers having a molecular weight of 2300 or more have been found to be particularly beneficial in providing an increase in power output under low speed / low load conditions.

[0087] Also surprisingly, the use of a combination of low molecular weight, preferably highly reactive polybutene having a number average molecular weight of 500 to 10,000 g / mol and present in an amount of 500 weight ppm to 5000 weight ppm of the fuel composition has been found to provide advantages with respect to the reduced combustion duration of a liquid fuel composition containing said polybutene compared to an internal combustion engine fueled by a liquid-based fuel.

[0088] The present invention will be further understood from the following examples. Unless otherwise specified, all amounts and concentrations disclosed in the examples are based on the weight of the fully formulated fuel composition.

Examples

[0089] Example 1 A set of experiments on the combustion promotion characteristics of highly reactive polyisobutylene (PIB) was conducted using a gasoline single cylinder engine (GSCE). The base fuel was a RON 96 E10 base gasoline fuel containing 28% aromatics that complied with the North American premium standard ASTM D4814 and did not contain performance additives. Highly reactive polyisobutylene (PIB) with a number average molecular weight (M n ) of 1000 g / mol, commercially available from BASF under the trade name Glissopal® 1000, was added to the base fuel at a treatment rate of 5000 ppm.

[0090] Test Conditions The engine used in these experiments was a gasoline single cylinder engine. This engine was manufactured by AVL and was based on the EA888 2.0L Audi TFSI / VW TSI (Euro 6). The details of the single cylinder bench engine are shown in Table 1 below.

[0091]

Table 1

[0092] The engine test conditions are detailed in Table 2 below.

[0093]

Table 2

[0094] The following test protocol was carried out using the base fuel and one test fuel per day. · Warm up the engine and adjust the base fuel · Perform baseline spark sweeps: 1300 ML, HL, 3000 ML (ML = medium load; HL = high load) · Switch to the test fuel and flash 30 liters · Test: Spark sweeps at three different conditions (1300 rpm, IMEP: 11.5 bar and 8 bar, and 3300 rpm, IMEP: 12.4 bar). · End.

[0095] Each test fuel blend was screened twice, once in each of the two randomization loops.

[0096] The average maximum pressure (P max ) generated by the combustion of the base fuel and the test fuel (Example 1) is shown in Table 3 below and in Figures 1 and 2.

[0097]

Table 3

[0098] Figure 1 shows the average P max generated by the combustion of the base fuel and the test fuel (Example 1) at 1300 rpm and 11.5 bar.

[0099] Figure 2 shows the average P max generated by the combustion of the base fuel and the test fuel (Example 1) at 3300 rpm and 12.4 bar.

[0100] Examples 2 - 7 Using the same base fuel as in Example 1 above and the same test conditions and test protocol as those used in Example 1 above, another set of experiments was conducted on several additional test fuel blends. The test fuel blends of Examples 2 - 7, each containing highly reactive PIB, are shown in Table 4 below. The molecular weights of the highly reactive PIBs used in each fuel are shown in parentheses in column 2 of Table 4. Two different HR - PIBs were used, one having a number average molecular weight of 1000 g / mol and being commercially available from BASF under the trade name Glissopal® 1000, and the other having a number average molecular weight of 2300 g / mol and being commercially available from BASF under the trade name Glissopal® 2300. The processing rate, RON, MON, and RON - MON of each of the test blends are also shown in Table 4.

[0101]

Table 4

[0102] P max And the combustion duration was measured for each of Examples 2 to 7, as well as for the base fuel, and the results are shown in Table 5 below. Table 5 also shows the % difference in P max and combustion duration between each test blend and the base fuel control experiment on that day.

[0103] P max And the combustion duration are metrics well known to those skilled in the art. The start of combustion is ignition, and the end of combustion is at the point of maximum pressure P max . The combustion duration is the time interval from 10% to 90% of combustion. Further information on how the combustion duration is calculated can be found in Hosseini, Vahid & Checkel, M. (2006), ‘Using reformer gas to enhance HCCI combustion of CNG in a CFR Engine’, SAE Technical Papers, DOI: 10.4271 / 2006-01-3247. The combustion duration (Burn duration) (or combustion duration) can be determined by the pressure curve as shown in Figure 1 of Hosseini et al.'s paper. Figure 1 of Hosseini et al.'s paper shows AI10-90 and how it relates to the maximum net heat release (HRN) and the maximum pressure release (P max ). Either temperature or pressure can be used to calculate the combustion metrics. In this example, the in-cylinder pressure was used to determine the combustion duration.

[0104]

Table 5

[0105] Figure 3 shows the P in Table 5 maxGraphical representation of data, showing the average P generated by the combustion of the base fuel and test fuel for each day at 1300 rpm and 11.5 bar (IGN 2 degrees BTDC). max (Examples 2 - 7).

[0106] Figure 4 is a graphical representation of the P max data, showing the average % difference in Pmax for each of Examples 7 - 11 relative to the base fuel control experiment for that day (the base fuel results in Table 5 are normalized to 0).

[0107] Figure 5 is a graphical representation of the combustion duration data in Table 5, showing the average % difference in combustion duration for each of Examples 7 - 11 relative to the base fuel control experiment for that day (the base fuel results in Table 5 are normalized to 0).

[0108] Examples 8 and 9 Another set of experiments was conducted on several additional test fuel blends using a base fuel different from that used in Example 1. The base fuels used in Examples 8 and 9 were RON 92 E10 gasoline fuels containing 6.8% aromatics that comply with the North American major grade standard ASTM D4814 and do not contain performance additives. Examples 8 and 9 used the same test conditions and test protocol as those used in Example 1 above. The test fuel blends of Examples 8 and 9, each containing highly reactive PIB, are shown in Table 6 below. The molecular weights of the highly reactive PIB used in each fuel are shown in parentheses in column 2 of Table 6. Two different HR - PIBs were used, one having a number average molecular weight of 1000 g / mol and being commercially available from BASF under the trade name Glissopal® 1000, and the other having a number average molecular weight of 2300 g / mol and being commercially available from BASF under the trade name Glissopal® 2300. The treatment rate, RON, MON, and RON - MON for each of the test blends are also shown in Table 6.

[0109] [Table 6]

[0110] P max And the combustion duration was measured for each of Examples 8 and 9, as well as for the base fuel, and the results are shown in Table 7 below. Table 7 also shows the P max and the % difference in combustion duration between each test blend and the base fuel control experiment for that day.

[0111]

Table 7

[0112] Figure 6 is a graphical representation of the P max data, showing the average P max generated by the combustion of the base fuel and test fuels for each day at 1300 rpm and 11.5 bar (1 degree of IGN after TDC) (Examples 8 - 9).

[0113] Figure 7 is a graphical representation of the combustion duration data in Table 7, showing the average combustion duration for each of Examples 8 - 9 at 1300 rpm, 11.5 bar (1 degree of IGN after TDC) relative to the base fuel control experiment for that day.

[0114] Discussion The use of 5000 weight ppmw of low molecular weight highly reactive PIB having a molecular weight of 1000 g / mol in a gasoline fuel composition provided increased power (increased P max ) relative to the base fuel under both low speed / low load and high load / high speed conditions in engine tests (Example 1).

[0115] Furthermore, the use of 2500 ppmw and 5000 ppmw of low molecular weight highly reactive PIB having a molecular weight of 1000 g / mol in a gasoline fuel composition provided increased power (increased P max ) under low speed / low load conditions in engine tests (Examples 2 - 4).

[0116] Furthermore, the use of 2500 ppmw and 5000 ppmw of low molecular weight, highly reactive PIB having a molecular weight of 2300 g / mol in a gasoline fuel composition provides increased power (increased P max ) under low speed / low load conditions in an engine test, as compared to the base fuel (Examples 5 - 7). Highly reactive PIB having a higher molecular weight (M w = 2300 g / mol) appears to provide a greater increase in power under low speed / low load conditions as compared to highly reactive PIB having a lower molecular weight (M w = 1000 g / mol).

[0117] Furthermore, the use of 5000 ppmw of highly reactive PIB having a molecular weight of 1000 g / mol in a gasoline fuel composition has been shown to provide a reduced combustion duration as compared to the base fuel (Examples 2 - 4).

[0118] Furthermore, the use of 2500 ppmw and 5000 ppmw of highly reactive PIB having a molecular weight of 2300 g / mol in a gasoline fuel composition has been shown to provide a reduced combustion duration as compared to the base fuel (Examples 5 - 7).

[0119] Furthermore, the use of 5000 ppmw of highly reactive PIB having a molecular weight of 1000 g / mol in a gasoline fuel composition has been shown to provide increased power (increased Pmax) under low speed / low load conditions in an engine test as compared to the base fuel (Example 8).

[0120] Furthermore, the use of 5000 ppmw of highly reactive PIB having a molecular weight of 2300 g / mol in a gasoline fuel composition has been shown to provide increased power (increased Pmax) under low speed / low load conditions in an engine test as compared to the base fuel (Example 9).

[0121] Furthermore, the use of 5000 ppmw of highly reactive PIB having a molecular weight of 1000 g / mol in a gasoline fuel composition has been shown to provide a reduced combustion duration as compared to the base fuel (Example 8).

[0122] Furthermore, the use of 5000 ppmw of highly reactive PIB having a molecular weight of 2300 g / mol in a gasoline fuel composition has been shown to provide a reduced combustion duration compared to the base fuel (Example 9).

Claims

1. A fuel composition comprising: (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine; and (b) a polybutene polymer, wherein the polybutene polymer has a number average molecular weight in the range of 200 to 10,000 g / mol, more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, and the polybutene polymer is present at a level of 500 to 5000 weight ppm in the fuel composition.

2. The fuel composition according to claim 1, wherein more than 40% of the polymer molecules in the polybutene polymer have terminal vinylidene groups.

3. The fuel composition according to claim 1 or 2, wherein more than 50% of the polymer molecules in the polybutene polymer have terminal vinylidene groups.

4. The fuel composition according to any one of claims 1 to 3, wherein the polybutene polymer has a number average molecular weight in the range of 500 to 5,000 g / mol.

5. The fuel composition according to any one of claims 1 to 4, wherein the polybutene polymer has a number average molecular weight in the range of 1000 to 2,300 g / mol.

6. The fuel composition according to any one of claims 1 to 5, wherein the polybutene polymer has a number average molecular weight in the range of 2,300 to 5,000 g / mol.

7. The fuel composition according to any one of claims 1 to 6, wherein the polybutene polymer is present at a level of 1000 to 5000 weight ppm in the fuel composition.

8. The fuel composition according to any one of claims 1 to 7, wherein the polybutene polymer is present at a level of 2500 to 5000 weight ppm in the fuel composition.

9. The fuel composition according to any one of claims 1 to 8, wherein the polybutene polymer is a polyisobutylene polymer.

10. Use of a liquid fuel composition for improving the power output of an internal combustion engine, wherein the liquid fuel composition comprises: (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine; and (b) a polybutene polymer. The use of the polybutene polymer having a number average molecular weight in the range of 200 to 10,000 g / mol, wherein the polybutene polymer is present at a level of 500 to 5000 ppm by weight of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polyisobutylene polymer have terminal vinylidene groups.

11. The use of a liquid fuel composition for improving the Pmax of an internal combustion engine, wherein the liquid fuel composition comprises (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, the polybutene polymer having a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer being present at a level of 500 to 5000 ppm by weight of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, the use of a liquid fuel composition for improving the Pmax of an internal combustion engine.

12. The use of polybutene in a liquid fuel composition for reducing combustion duration, wherein the liquid fuel composition comprises (a) a gasoline-based fuel suitable for use in a spark-ignition internal combustion engine, and (b) a polybutene polymer, the polybutene polymer having a number average molecular weight in the range of 200 to 10,000 g / mol, the polybutene polymer being present at a level of 500 to 5000 ppm by weight of the fuel composition, preferably the polybutene is a highly reactive polybutene, and more than 30% of the polymer molecules in the polybutene polymer have terminal vinylidene groups, the use of polybutene in a liquid fuel composition for reducing combustion duration.

13. A method for increasing the power output of a spark-ignition internal combustion engine, the method comprising adding polybutene to a gasoline-based fuel to produce a gasoline fuel composition in which the polybutene polymer is added at a level of 500 to 5000 ppm by weight of the gasoline fuel composition, the polybutene having a number average molecular weight in the range of 200 to 10,000 g / mol, and burning the fuel composition in the spark-ignition internal combustion engine, the method for increasing the power output of a spark-ignition internal combustion engine.

14. A method for reducing the combustion duration of a gasoline fuel composition in a spark-ignition internal combustion engine, the method comprising adding polybutene to a gasoline-based fuel to produce a gasoline fuel composition in which the polybutene polymer is added at a level of 500 to 5000 weight ppm of the gasoline fuel composition, and the polybutene has a number average molecular weight in the range of 200 to 10,000 g / mol, and burning the fuel composition in the spark-ignition internal combustion engine. A method for reducing the combustion duration of a gasoline fuel composition in a spark-ignition internal combustion engine.

15. The method according to claim 13 or 14, wherein the polybutene has more than 30% of the polymer molecules in the polybutene polymer having terminal vinylidene groups.

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