Alcohol and ether fuel additives for unleaded gasoline

Abstract

The octane boosting additive comprises a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer, the mixed butanol composition comprising sec-butyl alcohol and tert-butyl alcohol, and the C4-dimer comprising diisobutylene, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane or a combination comprising at least one of the foregoing.

Description

Technical Field

[0001] The present invention relates to a fuel additive for gasoline, gasoline containing the additive and a method for preparing the gasoline. Background Art

[0002] Commercial gasoline as a fuel for internal combustion engines is a refined petroleum product, which is usually a mixture of hydrocarbons (base gasoline), additives and blending agents. In order to improve the performance and stability of gasoline, additives and blending agents are added to the base gasoline, such as octane enhancers, etc.

[0003] Gasoline has a tendency to "knock" when used in high compression internal combustion engines. Knock occurs when the combustion of the air / fuel mixture in the cylinder does not initiate properly in response to ignition because one or more pockets of the air / fuel mixture pre-ignite outside the housing of the normal combustion front. Anti-knock agents, which are also known as octane boosters, reduce the engine knock phenomenon and increase the octane rating of the gasoline. Existing octane boosters, such as tetraethyl lead and methylcyclopentadienyl manganese tricarbonyl (MMT), have been or are being phased out for environmental, health or other reasons.

[0004] Preferred compounds currently used to formulate octane boosters include C4 oxygenated compounds, such as methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and n-butanol and its isomers. However, it can be expensive to produce and store large quantities of these materials in refineries. In addition, regulatory requirements restrict the use of high concentrations of additives, increasing the difficulty and expense of refining operations to produce high-octane fuels. A fuel additive or fuel is needed that has an octane rating comparable to gasoline and has increased combustion efficiency.

[0005] In view of the foregoing, there remains a need to provide cost-effective octane boosting compositions and gasoline compositions comprising the same. Summary of the invention

[0006] Disclosed in various embodiments are octane-enhancing additives, gasoline compositions containing the octane-enhancing additives, and methods of making the gasoline compositions.

[0007] The octane boosting additive includes a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and C4-dimer, the mixed butanol composition comprising sec-butyl alcohol and tert-butyl alcohol, and the C4-dimer comprising diisobutylene, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane, or a combination comprising at least one of the foregoing.

[0008] The gasoline composition includes a base gasoline and an octane boosting composition disclosed herein.

[0009] The method for preparing the gasoline composition comprises combining a base gasoline and an octane boosting composition disclosed herein to form a gasoline composition.

[0010] The method for preparing a gasoline composition comprises combining a base gasoline with a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and a C4-dimer, wherein the mixed butanol composition comprises sec-butyl alcohol and tert-butyl alcohol, and the C4-dimer comprises diisobutylene, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane, or a combination comprising at least one of the foregoing.

[0011] The above described and other features are illustrated by the following detailed description. DETAILED DESCRIPTION

[0012] New combinations of oxygenate additives, octane boosting compositions comprising the new combinations of oxygenate additives, and gasoline compositions comprising the new octane boosting compositions are described herein. The inventors have discovered that gasoline compositions comprising the new octane boosting compositions disclosed herein are characterized by an increased octane number, providing better combustion and improved performance in internal combustion engines, particularly for the automotive market. In particular, gasoline compositions comprising the new combinations of oxygenate additives can provide better performance than gasoline compositions containing ethanol, MTBE or butanol as the only oxygenate additives.

[0013] The terms "fuel oxygenate", "gasoline oxygenate" and simply "oxygenate" refer to a class of gasoline additives that contain one or more oxygen atoms and are effective to improve the octane rating of gasoline by increasing the oxygen content of gasoline. Most oxygenates are alcohols or ethers, such as methanol (MeOH), ethanol (EtOH), isopropyl alcohol (IPA), n-propyl alcohol (NPrOH), isobutyl alcohol (IBA), n-butyl alcohol (BuOH), sec-butyl alcohol (SBA), tert-butyl alcohol (TBA) or gasoline-grade tert-butyl alcohol (GTBA), tert-amyl alcohol (TAA) or tert-amyl alcohol, methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-amyl ethyl ether (TAEE), tert-hexyl methyl ether (THEME) and diisopropyl ether (DIPE). These oxygenates can be prepared by any known and acceptable chemical and biological reactions known in the art, such as chemical reactions between isobutylene and methanol or ethanol to prepare MTBE or ETBE, respectively, microbial fermentation of sugars to prepare bioethanol, etc. The preparation method may further include purification, distillation or dehydration steps to increase purity and remove water.

[0014] The novel combination of oxygenated additives comprises a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer.

[0015] The mixed butanol composition comprises sec-butyl alcohol and the tert-butyl alcohol. The relative proportion of sec-butyl alcohol and the tert-butyl alcohol can be widely changed, for example 1:99 to 99:1, or 10:90 to 90:10, or 20:80 to 80:20, or 30:70 to 70:30 sec-butyl alcohol: the volume ratio of the tert-butyl alcohol. In one embodiment, sec-butyl alcohol: the volume ratio of the tert-butyl alcohol is 2:1 to 3:1. The preferred volume ratio is 2.4:1. The mixed butanol composition can further comprise n-butyl alcohol, isobutyl alcohol or a combination thereof. The amount of n-butyl alcohol, isobutyl alcohol or a combination thereof can be 1 to 90 volume percent (volume %), 1 to 80 volume %, or 1 to 70 volume %, or 1 to 60 volume %, or 1 to 50 volume %, or 1 to 40 volume %, or 1 to 30 volume %, or 1 to 20 volume %. In one embodiment, the amount of n-butyl alcohol, isobutyl alcohol or a combination thereof is 84 volume %.

[0016] The C4-dimer comprises diisobutylene; 2,2,4-trimethylpentane; 2,3,3-trimethylpentane; or a combination comprising at least one of the foregoing. There is no particular limitation on the relative amount of each of the foregoing components in the C4-dimer composition.

[0017] The mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer can be added to the base gasoline to form the gasoline composition. The mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer can each be added individually to the base gasoline.

[0018] Alternatively, at least two of the mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and C4-dimer may be blended to form a premixed octane boosting additive. In some embodiments, the mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and C4-dimer may be blended in a single octane boosting composition. The octane boosting composition may then be added to a base gasoline to obtain a gasoline composition.

[0019] Therefore, the octane boosting composition comprises a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer. The mixed butanol composition can be present in the octane boosting composition in an amount of 2 to 35 volume %, or 3 to 29 volume %, or 0.6 to 30 volume %. C-4 dimer can be present in the octane boosting composition in the range of 0.1 to 3 volume % or 0.19 to 2 volume %. Methanol can be present in the octane boosting composition in an amount of 0.4 volume % to 2 volume %, or 0.50 volume % to 0.9 volume %, or 0.55 volume % to 0.80 volume %. MTBE can be present in the octane boosting composition in an amount of 65 to 99.8 volume %, or 68 to 99.3 volume %, or 70 to 95 volume %. Each of the foregoing amounts is based on the total volume of the octane boosting composition, i.e., the total volume of the mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer.

[0020] The octane boosting composition or its components can be added directly to the base gasoline. However, the octane boosting composition or its components can be diluted with a substantially inert, usually liquid organic diluent (e.g., mineral oil, naphtha, benzene, toluene or xylene) to form an additive concentrate. These concentrates can contain 0.1 to 80% by weight, or about 1 to 80% by weight, or 10 to 80% by weight of the octane boosting composition, and can additionally contain one or more other additives known in the art as described below. Concentrations such as 15%, 20%, 30% or 50% or more can be used. The concentrate can be prepared by combining the desired components in any order at any temperature (e.g., at 23 to 70° C.).

[0021] Also disclosed is a gasoline composition comprising a base gasoline and an octane boosting composition disclosed herein. In the gasoline composition, the base gasoline is present in an amount of 60 to 97 volume %, preferably 65 to 95 volume %, more preferably 70 to 90 volume %. The octane boosting composition may be present in the gasoline composition in an amount of 3 to 40 volume %, preferably 5 to 35 volume %, preferably 10 to 30 volume %, each amount being based on the total volume of the gasoline composition.

[0022] The gasoline composition may be prepared by combining a base gasoline and the components of the octane boosting composition disclosed herein, either alone or in any combination.

[0023] The mixed butanol composition may be present in the gasoline composition in a total amount of 0.5 to 20 volume %, preferably 0.7 to 10 volume %, more preferably 0.8 to 5 volume %, each based on the total volume of the gasoline composition.

[0024] Methanol may be present in the gasoline composition in a total amount of 0.02 to 0.3 volume %, preferably 0.04 to 0.25 volume %, more preferably 0.08 to 0.20 volume %, each based on the total volume of the gasoline composition.

[0025] Sec-butyl ether and methyl tert-butyl ether may be present in the gasoline composition in a total amount of 0.02 to 30% by volume, preferably 0.06 to 26% by volume, each based on the total volume of the gasoline composition.

[0026] The C4-dimer may be present in the gasoline composition in an amount of 0.01 to 2% by volume, preferably 0.04% to 1% by volume, each based on the total volume of the gasoline composition.

[0027] The octane boosting composition may further comprise other additives known in the art, such as defoamers, anti-icing agents, additional anti-knock agents, antioxidants, anti-wear agents, color stabilizers, corrosion inhibitors, detergents, dispersants, dyes, extreme pressure agents, lead scavengers, metal passivators, pour point depressing agents, upper cylinder lubricants, viscosity improvers, etc. The amount of such additives depends on the specific additives and can be readily determined by one of ordinary skill in the art.

[0028] Defoamers used to reduce or prevent the formation of stable foam include silicones or organic polymers. Examples of antioxidants, corrosion inhibitors and extreme pressure agents are chlorinated aliphatic hydrocarbons, organic sulfides and polysulfides, phosphorus esters including di- and tri-hydrocarbon phosphites, molybdenum compounds, etc. Other antioxidants, alkylated diphenylamines, hindered phenols, especially those having a tertiary alkyl group (e.g., a tertiary butyl group) ortho to the phenolic-OH group, etc.

[0029] Cleaners and dispersants may be of the ash-generating or ash-free type. Examples of ash-generating cleaners are oil-soluble neutral and basic salts of alkali or alkaline earth metals with sulfonic acids, carboxylic acids, phenols or organic phosphoric acids characterized by at least one direct carbon-phosphorus bond. Ash-free cleaners and dispersants may produce non-volatile residues such as boron oxide or phosphorus pentoxide when burned, but are generally metal-free and therefore do not produce metal-containing ash when burned. Examples include reaction products of carboxylic acids containing 34 to 54 carbon atoms (or derivatives thereof) with nitrogen-containing compounds such as amines, organic hydroxyl compounds such as phenols and alcohols, and / or basic inorganic materials.

[0030] Viscosity modifiers are typically polymers such as polyisobutylene, poly(methacrylates), hydrogenated diene polymers, polyalkylstyrenes, esterified styrene-maleic anhydride copolymers, hydrogenated alkenyl aromatic-conjugated diene copolymers, and polyolefins.

[0031] In particular, the octane number enhancing composition may further comprise other oxygenated compounds, such as other alcohols, esters or ether oxygenates. Examples of other alcohols that may be included are ethanol, isopropanol, n-propanol, tert-amyl alcohol or a combination comprising at least one of the foregoing, and examples of other ethers that may be included are ethyl tert-butyl ether, tert-amyl methyl ether, tert-amyl ethyl ether, tert-hexyl methyl ether, diisopropyl ether or a combination comprising at least one of the foregoing. Examples of esters that may be included are isoamyl acetate, amyl acetate, isoamyl propionate, isoamyl nonanoate, isobutyl acetate, methyl butyrate, methyl caproate, methyl octanoate or a combination comprising at least one of the foregoing. These additional oxygenated compounds may be present in an amount of 0.02 to 20% by volume or 0.1 to 10% by volume, each based on the gross volume of the gasoline composition.

[0032] Other anti-knock additives include xylene, benzene, toluene, aniline, etc.

[0033] The gasoline composition can be characterized as having a Reid vapor pressure (RVP) of 6.0 to 8.0, preferably 6.5 to 7.8 psi. The gasoline composition can also be characterized as having a research octane number (RON) that is higher than the base gasoline and a motor octane number (MON) that is higher than the base gasoline. For example, the gasoline composition can have a RON of 88 to 110, preferably 90 to 105, and a MON of 82 to 105.

[0034] The present disclosure is further illustrated by the following non-limiting examples.

[0035] Example

[0036] Example 1 Gasoline Blends with Fuel Additives

[0037] Various potential additives selected from alcohols, ethers or C4-dimers were added to a base gasoline having the properties shown below in Table 1. The composition of each gasoline blend is provided in Tables 2 and 3.

[0038] Table 1. Typical physical properties of base gasoline

[0039]

[0040]

[0041] The Reid Vapor Pressure (RvP), Research Octane Number (RON) and Motor Octane Number (MON) were measured for each blend.

[0042] RvP is a measure of gasoline volatility. It is defined as the absolute vapor pressure exerted by a liquid (such as gasoline) at 100°F (37.8°C) as determined by test method ASTM D 323.

[0043] RON describes the knock behavior at low engine loads and low speeds and is determined in accordance with DIN EN ISO 5164 (ASTM D 2699).

[0044] MON describes the behavior at high engine loads and under high thermal stresses and is determined in accordance with DIN EN ISO 5163 (ASTM D 2700).

[0045] The test results for the base gasoline and each blend are listed in Tables 2 and 3 below.

[0046] Table 2. RvP, RON and MON of gasoline blends

[0047]

[0048] Table 3. RvP, RON and MON of gasoline blends

[0049]

[0050] The present disclosure further encompasses the following aspects.

[0051] Aspect 1. An octane improving composition comprising a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer, wherein the mixed butanol composition comprises sec-butyl alcohol and tert-butyl alcohol, and the C4-dimer comprises diisobutylene, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane or a combination comprising at least one of the foregoing.

[0052] Aspect 2. The octane improving composition of aspect 1, wherein the mixed butanol composition further comprises n-butanol, isobutanol, or a combination thereof.

[0053] Aspect 3. The octane boosting composition of Aspect 1 or 2, wherein the methanol is present in an amount of 0.4 vol% to 2 vol%, 0.50 vol% to 0.9 vol%, or 0.55 vol% to 0.80 vol%.

[0054] Aspect 4. The octane boosting composition of any one or more of Aspects 1 to 3, wherein the methyl tert-butyl ether is present in an amount of 65 to 99.8 vol%, 68 to 99.3 vol%, 70 to 95 vol%.

[0055] Aspect 5. The octane boosting composition of any one or more of Aspects 1 to 4, wherein the mixed butanol composition is present in an amount of 2 to 35 vol%, 3 to 29 vol%, 0.6 to 30 vol%.

[0056] Aspect 6. The octane boosting composition of any one or more of Aspects 1 to 5, wherein the sec-butyl ether is present in a range of 0.3 to 5 vol%, 0.4 to 4 vol%.

[0057] Aspect 7. The octane boosting composition according to any one or more of aspects 1 to 6, wherein the C4-dimer is present in the range of 0.1 to 3 vol%, 0.19 to 2 vol%.

[0058] Aspect 8. The octane boosting composition according to any one or more of aspects 1 to 7, further comprising ethanol, isopropanol, n-propanol, tert-amyl alcohol, or a combination comprising at least one of the foregoing.

[0059] Aspect 9. The octane boosting composition according to any one or more of aspects 1 to 8, further comprising ethyl tert-butyl ether, tert-amyl methyl ether, tert-amyl ethyl ether, tert-hexyl methyl ether, diisopropyl ether, or a combination comprising at least one of the foregoing.

[0060] Aspect 10. A gasoline composition comprising a base gasoline and the octane enhancing composition of any one or more of aspects 1 to 9.

[0061] Aspect 11. The gasoline composition of aspect 10, having a Reid vapor pressure (RVP) of 6.0 to 8.0 psi.

[0062] Aspect 12. The gasoline composition of Aspect 10 or 11, having a research octane number (RON) higher than the RON of the base gasoline and having a motor octane number (MON) higher than the MON of the base gasoline.

[0063] Aspect 13. The gasoline composition of any one or more of Aspects 10 to 12, having a RON of 88 to 110 and a MON of 82 to 105.

[0064] Aspect 14. The gasoline composition of any one or more of Aspects 10 to 13, wherein the mixed butanol composition and methanol are present in a total amount of 0.5 to 10% by volume, 0.9 to 5% by volume of the gasoline composition.

[0065] Aspect 15. The gasoline composition of any one or more of Aspects 10 to 14, wherein the sec-butyl ether and methyl tert-butyl ether are present in a total amount of 0.02 to 30% by volume, preferably 0.06 to 26% by volume of the gasoline composition.

[0066] Aspect 16. The gasoline composition of any one or more of Aspects 10 to 15, wherein the C4-dimer is present in an amount of 0.01 to 3 vol%, preferably 0.04 vol% to 1 vol% of the gasoline composition.

[0067] Aspect 17. The gasoline composition according to any one or more of Aspects 10 to 16, wherein the base gasoline is present in 60 to 97% by volume, preferably 65 to 95% by volume, more preferably 70 to 90% by volume.

[0068] Aspect 18. A method for preparing a gasoline composition, comprising combining a base gasoline and components of the octane boosting composition of any one or more of aspects 1 to 9 to form a gasoline composition.

[0069] Aspect 19. The method of aspect 18, wherein the octane boosting composition is present in the gasoline composition in an amount of 3 vol% to 40 vol%, or preferably 5 vol% to 35 vol%, preferably 10 vol% to 30 vol%.

[0070] Aspect 20. The method of aspect 20, wherein the mixed butanol composition is present in the gasoline composition in a total amount of 0.5 to 20 volume %, preferably 0.7 to 10 volume %, more preferably 0.8 to 5 volume %.

[0071] Aspect 21. The method of any one or more of Aspects 18 to 20, wherein methanol is present in the gasoline composition in a total amount of 0.02 to 0.3% by volume, preferably 0.04 to 0.25% by volume, more preferably 0.08 to 0.20% by volume.

[0072] Aspect 22. The method of any one or more of Aspects 18 to 21, wherein the sec-butyl ether and methyl tert-butyl ether are present in the gasoline composition in a total amount of 0.02 to 30% by volume, preferably 0.06 to 26% by volume of the gasoline composition.

[0073] Aspect 23. The method of any one or more of Aspects 18 to 22, wherein the C4-dimer is present in the gasoline composition in an amount of 0.01 to 2 vol%, preferably 0.04 to 1 vol%.

[0074] Aspect 24. A gasoline composition prepared by the method of any one or more of aspects 18 to 23.

[0075] The compositions, methods and articles may alternatively comprise, consist of or consist essentially of any suitable material, step or component disclosed herein. The compositions, methods and articles may additionally or alternatively be formulated to be free of or substantially free of any material (or substance), step or component that is otherwise not necessary to achieve the function or purpose of the compositions, methods and articles.

[0076] All ranges disclosed herein include endpoints, and endpoints can be combined independently of each other (e.g., "up to 25% by weight, or more specifically, 5% by weight to 20% by weight" includes endpoints and all intermediate values ​​of the "5% by weight to 25% by weight" range, etc.). "Combination" includes blends, mixtures, alloys, reaction products, and the like. The terms "one" and "a" and "" do not represent quantitative limitations, but are to be interpreted as covering both the singular and the plural, unless otherwise specified herein or clearly refuted by the context. "Or" means "and / or", unless otherwise explicitly stated. References to "some embodiments", "one embodiment", etc. throughout this specification mean that specific elements described in connection with the embodiments are included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements can be combined in any suitable manner in various embodiments.

[0077] All test methods cited herein are those in effect on the priority date of this application.

[0078] Unless otherwise defined, technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the application belongs. All cited patents, patent applications and other documents are incorporated herein by reference in their entirety. However, if a term in the present application conflicts or contradicts a term in an incorporated document, the term from the present application takes precedence over the conflicting term from the incorporated document.

[0079] Although specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not currently foreseen or may not currently be foreseen may be generated by the applicant or other persons skilled in the art. Therefore, the appended claims as submitted and as may be amended are intended to include all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. An octane number improving composition comprising a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether and C4-dimer, The mixed butanol composition comprises secondary butanol and tertiary butanol, The C4-dimer comprises at least one of diisobutylene, 2,2,4-trimethylpentane and 2,3,3-trimethylpentane, wherein methanol is present in an amount of 0.4 volume % to 2 volume %, wherein methyl tert-butyl ether is present in an amount of 65 to 95 volume %; wherein the mixed butanol composition is present in an amount of 2 to 35 volume %; and The sec-butyl ether is present in the range of 0.3 to 5 volume %.

2. The octane boosting composition according to claim 1, wherein the mixed butanol composition further comprises n-butanol or isobutanol or a combination thereof.

3. The octane boosting composition according to claim 1 or 2, wherein methanol is present in an amount of 0.50% to 0.9% by volume; wherein methyl tert-butyl ether is present in an amount of 70 to 95 volume %; wherein the mixed butanol composition is present in an amount of 3 to 29 volume %; and The sec-butyl ether is present in the range of 0.40 to 5 volume %.

4. The octane boosting composition according to claim 1 or 2, wherein the C4-dimer is present in the range of 0.1 to 3 volume %.

5. The octane improving composition according to claim 1 or 2, further comprising ethanol, isopropanol, n-propanol, tert-amyl alcohol or a combination comprising at least one of the foregoing.

6. The octane boosting composition of claim 1 or 2, further comprising ethyl tert-butyl ether, tert-amyl methyl ether, tert-amyl ethyl ether, tert-hexyl methyl ether, diisopropyl ether, or a combination comprising at least one of the foregoing.

7. A gasoline composition comprising a base gasoline and the octane number improving composition according to claim 1.

8. The gasoline composition of claim 7 having a Reid vapor pressure of 6.0 to 8.0 psi; or having a research octane number that is higher than the research octane number of the base gasoline, and having a motor octane number that is higher than the motor octane number of the base gasoline.

9. The gasoline composition of claim 7 having a research octane number of 88 to 110 and a motor octane number of 82 to 105.

10. The gasoline composition of claim 7, wherein the mixed butanol composition and methanol are present in a total amount of 0.5 to 10 volume % of the gasoline composition.

11. The gasoline composition of claim 7, wherein the sec-butyl ether and the methyl tert-butyl ether are present in a total amount of 0.02 to 30 volume % of the gasoline composition.

12. The gasoline composition of claim 7, wherein the C4-dimer is present in 0.01 to 3 volume % of the gasoline composition.

13. The gasoline composition of claim 7, wherein the base gasoline is present in 60 to 97 volume percent.

14. A method for preparing a gasoline composition comprising A base gasoline and the components of the octane boosting composition of claim 1 are combined to form a gasoline composition.

15. The method of claim 14, wherein the octane boosting composition is present in the gasoline composition in an amount of 3% to 40% by volume.

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