JPS596285A - Gasoline composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel composition, and more particularly to a gasoline composition for spark ignition internal combustion engines.

Such sorbent compositions consist of a mixture of hydrocarbons and other additives. Gasoline compositions are required to vaporize over a range of temperatures to provide satisfactory hot and cold starting characteristics and efficient engine operation.

For this purpose nine gasoline compositions are generally used each with 25
It has an initial and final boiling point in the range of ~65°C and 200-220°C. Gasoline compositions are often varied seasonally and/or regionally to accommodate variations in average ambient temperature. For typical gasoline economic reasons, gasoline compositions typically contain as much butane as satisfactorily vapor pressure and boiling range properties are obtained.

Spark ignition internal combustion engines, such as engines used in automobiles, typically have relatively large compression ratios for efficiency reasons. For such internal combustion engines, fuels with high octane ratings are required, with research octane numbers (RON) typically above 80, more commonly 8.
Gasoline compositions having a FION of 5 or above and in most cases above 90 JM and in fact in the range of 95 to 100 are widely used for premium grade fuels.

To achieve the desired octane rating, one common JLJr'!
Additives are blended into the gasoline composition. Lead compounds such as tetraethyl lead are also widely used octane improvers. However, high lead content gasoline is undesirable due to environmental concerns. It is said that the emission of exhaust gases from internal combustion engines into the atmosphere causes pollution and poses a risk of health problems. Such exhaust gases contain - not only lead compounds which themselves pose a risk of pollution and communicable health problems - but also various nitrogen oxides which are also harmful. To reduce nitrogen oxide emissions, it is often desirable to use a catalytic converter in the exhaust system to convert nitrogen oxides to less harmful substances. However, the catalyst in such converters is often poisoned by lead compounds in the exhaust gas.

Because of these environmental concerns, the maximum amount of lead that can be included in gasoline is often regulated; many countries have regulated the maximum amount of lead below 0.4 gPh/l, and some In Japan, it is regulated to 15 g Ph/l or less. Some countries even use lead-free Ganlin.

In addition to lead compounds, conventionally used octane-enhancing additives include needles and alcohols1, such as methyl t-butylemthyl (MTBE), t, -7
'Tanol alone or in mixtures with other alcohols (e.g. ethanol).

The blended RON of these additives varies depending on the gasoline used for RON measurement and the amount of additive used.
Although there is some variation, a typical plain) RON is as follows:

t-Butanol approx. 108 Ethanol 110-120MTBE
Although the 115-13'5 measurements indicate that methanol has a high blended RON, the actual benefit seen in normal automotive use is significantly lower than what would be expected from its plain) RON.

MTBE has high blend Ft ON '4;
Although it has a relatively low boiling point (55°C), its use as an octanization improver has the disadvantage of reducing the amount of butane that can be included in the gasoline composition. Methanol also has the same drawbacks. We have found that dialkyl carbonates can be used to improve the octane number of gasoline without the drawbacks mentioned above.

Conventionally, dialkyl carbonates have been disclosed in U.S. Patent No. 2 Roro 1.
No. 686, it was proposed as a gasoline additive in the US patent specification:
(DEC) is said to have a blend octane number of 96-98 when used in gasoline with an octane restriction of 74-79. In measurements we have made on gasolines with high RON, the DEC is between 110 and 112.
and unexpectedly dimethyl carbonate (DMG) was shown to have an even higher blend RON of 120-160 or even higher.

DEC and other dialkyl carbonates such as di-n-propyl carbonate (DPG) and di-n
-butyl carbonate (DBG), and other lead-free octane improvers such as alcohols (e.g. methanol, ethanol, t-butanol) and MTBE.

DMC has many drawbacks. Among other things, DMG has a significantly high specific gravity and a very low net calorific value (net calorific value: the heat of combustion minus the heat released by condensation of the water vapor produced during combustion, since such water vapor is not absorbed by the internal combustion engine). (This is because it is not condensed and is released together with the exhaust gas.)

However, DMG's unexpectedly high blend RON is 17.
more than makes up for these shortcomings, making DMG particularly useful as an octane improver.

According to the present invention, there is thus provided a gasoline composition comprising gasoline hydrocarbons and 1 to 6% DMC by volume based on the volume of the composition and having at least 800 RON.

Another disadvantage of octane-enhancing agents such as alcohols is their water miscibility. The use of water-miscible additives creates storage problems, particularly when using water-filled gasoline storage tanks that provide a certain bottom level. Not only are water-miscible additives susceptible to leaching from gasoline into the aqueous phase when stored in such bottom waters, but the presence of such water-miscible additives in gasoline also increases the water content of gasoline. The solubility of is increased.

The specific gravity, net heating value and water solubility of DMC compared to other dialkyl carbonates and other gasoline additives are listed in the table below.

Although DMC is highly soluble in water, and its solubility is significantly greater than that of other dialkyl carbonates, the partition coefficient of DMG between gasoline and the aqueous phase favors dissolution in gasoline. It is a value. Furthermore, D into the water
Despite the large solubility of MC, D in gasoline
The increase in water solubility in gasoline resulting from the incorporation of MC is significantly lower than that resulting from the incorporation of DEC into gasoline.

DMC can be easily produced from feedstocks other than crude oil, and its use therefore allows more fuel to be obtained from a given amount of crude oil.

DMC can therefore be prepared from methanol by reaction with carbon monoxide and oxygen over a suitable catalyst (eg steel chloride) [eg Ind, Eng, Chem.

Prod, Res, Dev, (1980) 19.3
96-403).

It can also be produced by reacting ethylene oxide with carbon dioxide to produce ethylene carbonate, which is then reacted with methanol to produce DMC and ethylene glycol (see, e.g., U.S. Pat. Nos. 3,642,858 and 3,803,201). reference)
.

The gasoline composition of the present invention contains other additives.

For example, viscosity modifiers, gum suppressants, and other mectane value improvers 1, such as other dialkyl carbonates,
Alcohols or ethers (e.g. t-butanol, MTBE), tetraalkyl lead compounds 1 Lead compounds such as tetraethyl lead, tetramethyl lead,
May include. However, due to the environmental concerns mentioned above, the lead content is 0.41/Ph/1, preferably 0.15.9'
It would be appropriate to set it as Ph/l. In particular, it is preferred that the gasoline composition be substantially free of marine.

Dialkyl carbonates that can be used in combination with DMC (boiling point 90°C) are dialkyl carbonates of formula 1 R-0-H (R1 and R2 are each an alkyl group and may be the same or different). The total number of carbon atoms in both alkyl groups R and R is from 3 to 8).

Examples of such dialkyl carbonates include:

Approximate boiling point ('C,) Diethyl carbonate (DEC) 127 Ethyl methyl carbonate 109 Gene
-Propyl carbonate (DPC,) 166 diisopropyl carbonate 147 Gene
-Butyl Carbonate (DBC) 20 B Diisobutyl Carbonate 190 Preferably each of the alkyl groups R and H contains less than 5 carbon atoms.

Since dialkyl carbonates and especially DMC have inferior calorific value when compared with hydrocarbons, the total amount of dialkyl carbonates (including dimethyl carbonate) is preferably 10% by volume or less of the gasoline composition. , the amount of DMG used is 1 to 6% by volume of the gasoline composition, whether it is used alone or in admixture with other dialkyl carbonates and/or other octanization improvers. The use of a high proportion of dialkyl carbonates (especially DM(1)) not only results in a lower heating value per composition 11, but also reduces the combustion of dialkyl carbonates compared to the fuel/air ratio required for combustion of hydrocarbons. This may require modification of the carburetor or fuel injector settings to allow for the different fuel/air ratios required for the formulation. No adverse effects.

The amount of DMG used is preferably 6 to 5% by volume. The use of such amounts of DMC generally increases the FION of lead-dusted gasoline or leaded gasoline with a copper content of less than 0.49 Ph// by about 1 to 2 units.

In some cases, a mixture of DMC and one or more dialkyl carbonates may be preferred over DMC alone. How can such a mixture be -
This is because, compared to DMG, it has a high calorific value per unit volume, a range of boiling points and vaporizability, and a low mutual solubility in water at 1.c'. All these properties are advantageous in spark ignition internal combustion engine gasoline compositions VC. However, such a mixture
Of course it has a lower blend FION than DMG alone.

A mixture of dialkyl carbonates can be conveniently produced by using an alcohol as the reactant for providing an alkyl group in the dialkyl carbonate production method described above, and using an alcohol mixture as the alcohol reactant. Such alcohol mixtures can be synthesized from synthesis gas consisting of -carbon oxide and hydrogen using suitable catalysts. Methods of making such alcohol mixtures are well known in the industry.

High grade (mainly C2-05) manufactured by those methods
The ratio of alcohol to methanol and the structure of alcohols higher than ethanol (i.e. branched or straight chain) will depend on the individual catalyst and synthesis conditions (e.g. H
2/CO ratio).

As mentioned above, a convenient method for producing dialkyl carbonates is to react an alkylene oxirane (e.g., ethylene oxide or propylene oxide) with carbon dioxide to form an alkylene carbonate, which is then reacted with an alcohol to form a dialkyl carbonate. glycol (for example, U.S. Pat. No. 36
42858 and 3803201). Glycols, which have a wide variety of uses, are often produced by the hydrolysis of alkylene oxiranes. Therefore, the conventional Dalycol production route for the hydrolysis of alkylene oxiranes - by replacing the hydrolysis step with an alkylene carbonate production step and then modifying the alkylene carbonate to react with an alcohol to produce dialkyl carbonates - In addition to producing glycols from alkylene oxiranes, the alcohols can also be produced.

One method used for the production of alkylene oxiranes, which are then hydrolyzed to the corresponding glycols, involves the reaction of an alkane with oxygen to form an alkyl hydroperoxide: R- H+O□ → R-00H Then the alkyl hydroxyl oxide and the alkene (
(e.g. propylene) (see, e.g. GB 1,060.i22 and GB 1,074,330). In general - the alkyl group R should be a tertiary alkyl group so that the human 90yl oxide has sufficient stability for use in reactions with alkenes. Therefore, the by-product of this reaction is that the alkylhydro
Alcohol ROH corresponds to ROOH.

The type of by-product alcohol ROH will, of course, depend on the alkane feedstock used to produce the hydro(4-hydroxy)ROOH. Depending on the alkyl group H, the by-product alcohol ROH may be subjected to a variety of uses, such as those described below.

(i) Directly as a gasoline additive - (I) Used in the production of dialkyl carbonates.

(iii) m water splitting to the corresponding alkene and the latter used as part of the alkene for the production of alkylene oxiranes - (1ψ dehydration to the corresponding alkene and the latter used for the ether production; (v) ether production Used as the alcohol component in the reaction with an alcoholic alkene.

The above uses will be explained in more detail.

(1) Alcohols containing 4 to 8 carbon atoms, especially t-
Butanol is useful as a gasoline additive. Mixtures of Alkanes 2 Such mixtures of alcohols can be prepared, for example by using suitable petroleum fractions. Therefore, by combining the above methods -
Dialkyl carbonates and one or more alcohols can be made and used as gasoline additives, and glycols can also be made with them for other uses.

(Ii) As mentioned above, the alkyl group B will generally be a tertiary alkyl group. Also, theoretically with 100% efficiency)
), only 1 mole of alcohol ROH is produced per mole of alkylene oxirane (which gives 1 mole of alkylene carbonate) - and only 1 mole of alcohol ROH is produced per mole of alkylene oxirane, which gives 1 mole of alkylene carbonate - and then Since 2 moles of alcohol are required for the reaction with the carbonate; some direct alcohol obtained from another source is required for the production of the dialkyl carbonate (as produced in the oxirane production reaction). (more than the amount of alcohol) required. Therefore, one suitable alkane raw material is used for the production of the alcohol FIOH, and another alcohol, (tl), is used as the additional alcohol.

Gasoline additives containing mixtures of dialkyl carbonates and/or one type of dialkyl carbonate (the two alkyl groups being different) can be prepared.

(+1i) If the alcohol FIOH has the same carbon skeleton as the desired glycol, then the alcohol can be mixed with water to give the corresponding alkene.

The alkene can be recycled to the oxirane-forming reaction and used as part of the alkene for the production of alkylene oxiranes (UK!'l;?'FMF.

i, 111,945). This allows the amount of alkene feedstock used for glycol production to be reduced, resulting in an increase in the amount of dialkyl carbonate produced using a given amount of alkene feedstock.

(1v) Flucol ROH can be dehydrated to form an alkene, which can then be reacted with an alcohol to produce an ether. Therefore, t-butanol (1-butylhydro is produced from isobutane via peroxide) can be dehydrated to isobutene, which can be reacted with methanol to obtain methyl t-butyl ether (MTBE). Also in this case.

By using a mixture of alkanes to obtain a mixture of alcohols and thus an alkene mixture, a mixture of ethers can be prepared. MTBE and similar ethers and ether mixtures are useful as gasoline additives.

Thus, by the above route, dialkyl carbonates and ethers, both useful as gasoline additives, can be produced in addition to glycols.

M Flucol ROH can be used as part or all of the aluminum to be reacted with the alkene to obtain the needle [see, eg, (1v) above]. Some or all of the alkene can be derived from a portion of the alcohol ROH by dehydration as in (1) above, while the remainder of the alcohol FIOH (alcohol obtained from other sources if desired).

(eg, mixed with methanol) and reacted with the alkene to obtain an ether or ether mixture useful as a gasoline additive.

When a mixture of alkanes is used to obtain a hydrosyl]oxide mixture and thus an alcohol mixture, the alcohol mixture is fractionated to provide k) the alcohols for one or more of the uses outlined above; of fractionated alcohol can be used for other of the above applications. For example, when considering applications (+V) and (v) above, hydroxy can fractionate the alcohol mixture produced from the mixture of ruoxides into a "high" part and a "low" part, and the "high" part is dehydrated. The "lower" portion can be reacted with the alkene or alkene mixture obtained from the "higher" portion to form an ether or ether mixture.

Of course, which of them to adopt when adopting the above uses of alcohol.

Depending on the type of raw materials used - it also depends on the desired end product. For example - in some cases it may be desirable to produce liquid fuels containing as additives not only at least one dialkyl carbonate, but also at least one alcohol and at least one ether in certain proportions.

The above uses (i), (+v) and/or (V) and optionally (i) if necessary can be used in combination in appropriate proportions to obtain the desired additives in the desired relative amounts. Of course, if a mixture of alkanes is used, it may be desirable to fractionate the alcohol mixture and direct each fraction to a separate use.

Thus, according to yet another aspect of the invention.

(+1 less (both dialkyl carbonate products consisting of one dialkyl carbonate, (i) at least one
1. An alcohol product A consisting of a species alcohol and/or an ether product consisting of at least one ether, and (iii) a glycol product consisting of at least one glycol, comprising: (a) at least One type of alkylhydro oxide is an alkene raw material B consisting of at least one type of alkene.
an alcohol material C containing at least one alkylene oxirane and the alcohol product A;
Let it generate.

(hl said/J) reacting at least one alkylene oxirane with at least a portion of carbon dioxide to produce at least one alkylene carbonate; , consisting of at least one alcohol and which may include a portion of the alcohol component C, to form the dialkyl carbonate product and the glycol product.

(d) separating the glycol product from the dialkyl carbonate product F+1 and optionally -(-) the alcohol) and dehydrating at least a portion of Material C by fire to give the alkene component E; [2] The acecene component E comprises at least one alcohol.

A portion of the alcoholic material C is esterified by reaction with alcohol component F, which may include a portion, to form the ether product.

There is provided a method for producing the above products (1), (i) and (iii) comprising:

The process described above can thus be used to upgrade an alkane feedstock into an alcohol product that is useful as a gasoline additive or as a reactant for the production of a Ganlin additive. The alkene raw material can be upgraded to a glycol product, and then to a dialkyl carbonate product useful as a nuclear alcohol product or as an additional alcohol component or gasoline additive.

According to yet another aspect of the present invention, there is provided a method for upgrading an alkane feedstock and an alkene feedstock to produce an alcohol product and a glycol product.

(1) A pod that reacts the alkane feedstock with oxygen to produce a hydrosulfate 9 product.

(ii) the hydroxy reacts the hydroxyl oxide product with the alkene feedstock to form an alkylene oxirane product and the alcohol product; and (iii)
The alkylene oxirane product is converted into the glycol product, and in the oil step, the alkylene oxirane product is reacted with carbon dioxide to form an alkylene carbonate product, and the alkylene carbonate product is used as an alcohol raw material. Converting the alkylene oxirane product to the glycol product by reacting to form the glycol product and the dialkyl carbonate; thus, the above process includes an improvement in which the alcohol feedstock is also upgraded with a gasoline additive. Be provided.

Catalysts and conditions suitable for carrying out the above reactions are known and therefore obvious to those skilled in the art, and therefore a detailed description thereof is omitted here.

In a preferred embodiment, isobutane is used as the alkane feedstock and the resulting hydrofluoric acid is reacted with propylene to obtain propylene oxide and t-butanol. Convert this propylene oxide to propylene carbonate.

This is reacted with methanol to produce propylene glycol and DMC-g, or by using ethylene in place of propylene, ethylene glycol and DMC-g are produced.
C was obtained 7). The t-butanol is preferably used as a fuel additive, either neat or mixed with DMC - or some or all of the t-butanol can be dehydrated to isobutene, which can be esterified with chemethanol to form MT.
BE and.

This can be used mixed with DMC and the remainder of the t-butanol, if any, can be used as a gasoline additive.

The invention is further illustrated in the following examples.

Example 1 The octane number of the fuel was determined using a CFR-ASTM single cylinder engine using a standard method (ASTM D2699). 6% υ/υ and 5% υ in pure isooctane
A blend of DMC of /υ was used as a sample. The research octane numbers obtained were as follows - 6% v/v DMCt7) Blend”RON=1305
Blend of %v/v DMC RON = 162 Example 2 Filtering various dialkyl carbonates in a gasoline composition consisting of 80% V/υ isooctane and 20% V/υ n-hebutane %v/v and 5% υ Example 1 was repeated using the /υ blend. Actual vehicle octane rating (
MON) was also measured using a standard method (ASTMD2700). The results are listed in the table below.

EXAMPLE Example 2 Example 2 was repeated using leaded premium grade gasoline in place of the octane/11-hebutane mixture. The gasoline used had a content of dialkyl carbonates of 7 Ph and 4.9 Ph respectively.
/l lead content.

The results are shown in the table below.

Examples 2 and 6 show that DMC provides much greater research octane improvement than other dialkyl carbonates in both leaded and lead-dusted gasolines.

Example 4 The effectiveness of dialkyl carbonates in reducing surface tension and interfacial tension chipping of hydrocarbon fuels was tested as described in US Pat. No. 23/10/86.

Place a precisely measured drop of Premiano, grade gasoline containing 6% dialkyl carbonate at 1.2 CI 7 on a polished metal plate.
It was dropped from a height of 1. The diameter of the resulting droplet film is measured and calculated as a percentage of the diameter value of the droplet film obtained from dialkyl carbonate-free gasoline.
It can be seen that DMG has only a slight, but negative, effect on droplet membrane expansion, although there is a fair agreement with the results described for DEC and DBC in the '6 specification.

Example 5 The distribution of DMC between gasoline and water was measured. Commercially available premium grade gasoline containing QJ 9Ph/11 lead (added DMC of various bamboo shoots in advance) and an equal volume of water (
The ambient temperature) was then VCIH.

Once equilibrium is reached, take samples of each phase.

DMC was analyzed. The results are shown in the table below.

For comparison, t-butanol (% in gasoline)
The distribution coefficient for methanol (concentration v/v) is approximately 0.26, while the coefficient for methanol is extremely small.

Example 6 The solubility of water in a commercial premium grade gasoline containing 0.4.9 parts per 17+ lead and a moderate amount of dialkyl carbonate was determined at -7°C and 21°C. Since the ys gasolines used for the different dialkyl carbonates were slightly different, the absolute solubilities are not strictly comparable. To provide a practical comparison, the solubility obtained by dialkyl carbonate formulations is shown in the table below.

Although DMC is quite soluble in water, it does not give a large increase in the solubility of water in gasoline, whereas DM
D has a much lower solubility in water than C.
It is clear that EC provides a significant increase in the solubility of water in gasoline.

Claims (1)

Claims: (11) A gasoline composition for a spark-ignition internal combustion engine, comprising gasoline hydrocarbons and 1 to 6% dimethyl carbonate by volume of the composition, according to at least 80 research studies.
The above gasoline composition having an octane number. (A gasoline composition according to claim 1 having a lead content of not more than 210,411 Ph/It; (a gasoline composition according to claim 2 having a lead content of not more than 310,15 gPh/l) (4) A gasoline composition according to any one of claims 1 to 7 having a research octane number of at least 90. (5) Also comprising at least one other dialkyl carbonate. The gasoline composition according to any one of claims 1 to 4, wherein the combined amount of dialkyl carbonates including: is less than 10% by volume of the composition. (6) 4 to 8 carbon atoms. The gasoline composition according to any one of claims 1 to 5, which also contains an alcohol and/or an ether in its molecule, and which contains a tertiary argyl group having a tertiary argyl group in its molecule. (7) The alcohol is butanol. (8) The gasoline composition according to claim 6, wherein the ether is methyl i, -1 dernider. 9) (i) a dialkyl carbonate consisting of at least one dialkyl carbonate, and the carbonate product -(1
) an alcohol product A consisting of at least one alcohol and/or an ether product consisting of at least one ether; and (iii) a dalicol product consisting of at least one glycol. , (σ) At least one alkyl hydroxide is reacted with an alkene feedstock B consisting of at least one alkene to form an alcohol compound containing at least one alkylene oxirane and the alcohol product A. C and - (/l) p reacting at least a portion of the at least one alkylene oxirane with carbon dioxide to produce at least one alkylene carbonate. (C) The core lacks at least one type of alkylene carbonate and consists of at least one type of alcohol. A portion of the alcohol material C may be reacted with an alcohol component to form the dialkyl carbonate product and the glycol product. (='l A small amount of the alcohol raw material C (and a part of it is dehydrated to become the -r alkene component E, and the alkene component E is
and at least one type of alcohol. Esterify to form the ether product by reacting with alcohol component F, which may include a portion of the alcohol material C. (f), (i) and (iii) above. OI A method for upgrading alkane raw materials and alkene raw materials to produce alcohol products and glycol products. (i) the hydro reacts the alkane feed with oxygen to form a peroxide product; (i) the hydro reacts the peroxide product with the alkene feed to form an alkylene oxirane product and an alcohol product; Generate, and (!!il Part 7
'Converting the lekylene oxirane product to the glycol product. Consists of each process. and (itil) reacting the alkylene oxirane product with carbon dioxide to form an alkylene carbonate product - reacting the alkylene carbonate product with an alcohol feed to form the glycol product and the dialkyl carbonate; The above process includes an improvement in converting the oxirane product to the glycol product; thus also upgrading the alcohol feedstock into a gasoline additive.