NL8005581A - CLEAR LIQUID FUEL MIXTURE FOR COMBUSTION ENGINES. - Google Patents

Abstract

The invention relates to a clear liquid fuel mixture for combustion engines which consist of: a. a liquid hydrocarbon mixture; b. 1-10 % by weight of water; c. 0.1-25 % by weight of methanol as alcohol fully soluble in water; d. 0.1-15 % by weight of surface-active substances; and e. 0.01-20% by weight of alcohols with 4 to 12 C atoms not or sparingly soluble in water.

Description

j * * i; * j I '' ’j - $ £ <71980 STAMICARBON B.V. "

Inventors: Wilhelmus A.B. DONNERS in Nieuwstadt Gerrit HOVESTREYDT in Geleen Marinus J.A.M. DEN OTTER at Munstergeleen 3233

CLEAR LIQUID FUEL MIXTURE FOR COMBUSTION ENGINES

The invention relates to a clear, liquid fuel mixture for internal combustion engines, which mixture comprises: a. A liquid hydrocarbon mixture; b. water; 5 c. a. water fully soluble alcohol and d. surfactants *

Such a clear, liquid fuel mixture is known from US patent 4,002,435.

The fuel mixture described in this patent consists of: 10 a. Gasoline or diesel oil; b. 0.1-10% water; c. 0.1-20% of a completely water-soluble alcohol and d. a combination of surfactants, consisting of: 1. a salt of a saturated or unsaturated higher fatty acid; 2. an unsaturated organic acid; and 3. an ethylene oxide condensation product.

According to this patent, to obtain a stable water-containing fuel mixture with a water-soluble alcohol, such as methanol, a special combination of surfactants is required to disperse alcohol and water in gasoline or oil. Methanol, ethanol, propanol or a mixture of these alcohols is used as the completely water-soluble alcohol.

The drawback of this fuel mixture is that it is relatively expensive because special surfactants are required to disperse the fully water-soluble alcohols in gasoline into a stable mixture over a wide temperature range.

Dutch patent application 7416290 relates to the operation of Otto and rotary piston engines using gasoline as fuel, at the same time as water-containing crude methanol. It is true that the alcohol used is inexpensive, but this is more than offset by the disadvantage that one motor vehicle 8005501 *

V

2 ï requires separate tanks and separate injection systems for the gasoline and for the water-containing raw methanol. Such a mixture will show phase separation when combined in advance, which makes application impossible. To be able to use this fuel, the necessary investments must be made per 5 motor vehicle.

European patent application 12345 relates to engines of jet fuels containing water and alcohol, in which a special and expensive nonionic emulsifier is used to obtain good stability, even in cold conditions. A relatively large amount of stirring energy is required to prepare a milky emulsion from the various components. Another drawback is that once this fuel mixture has stood for some time, or if unexpected water has entered it, agitation energy is again required to obtain an emulsion. This is quite problematic when this fuel mixture 15 is in the tank of a motor vehicle. Furthermore, it is difficult to determine whether phase separation has already taken place. The stability in cold also leaves much to be desired.

The aim of the invention is to overcome the above-mentioned drawbacks and to provide a clear liquid fuel mixture, as mentioned in the preamble, for combustion engines that is inexpensive, with no separation occurring even after a long standstill, which is stable at -20 ° C and whereby the various components can be mixed together into a clear liquid mixture, practically without stirring energy.

A further object of the invention is to provide a fuel mixture 25 in which there are relatively few hydrocarbons that are recovered from petroleum, and relatively many liquid raw materials that can be prepared from natural gas and / or coal. Furthermore, the fuel mixture must be applicable in the existing engines.

Higher, sparingly or sparingly water-soluble alcohols have been found to have a positive effect on increasing the stability range of clear, hydrocarbon, methanol and water-containing fuel mixtures, even when very small amounts of these higher alcohols are present. Very small quantities are understood to mean quantities in the order of 0.02% by volume.

35 It is of great importance that the stability area, i.e.

the area in which a clear mixture is obtained and / or maintained, especially at -20eC, is as large as possible. This greatly reduces the 8005581 * Vf 3 risk of phase separation in case of fluctuations in the composition of the mixture. Furthermore, this gives more freedom in the composition of the fuel mixture.

According to the invention, the clear fuel mixture 5 consists of: a. A liquid hydrocarbon mixture; b. 1-10 wt-Z water; c * 0.1-25 wt% methanol as completely water-soluble alcohol; d. 0.1-15 wt% surfactants and 10 e. 0.01-20% by weight of insoluble or sparingly water-soluble alcohols with 4-12 carbon atoms.

In the. water insoluble or sparingly soluble alcohols with 4-12 carbon atoms can also be divalent alcohols, such as, for example, diols. However, preference is given to monovalent alcohols.

The mixture can be converted into a clear whole in a very simple manner. This can be done by shaking, filling the storage tank or simply by transport.

It is assumed that a so-called micro-emulsion is formed, which is understood to mean a transparent, stable, liquid system, consisting of at least two immiscible or hardly miscible liquids, one liquid being dispersed in the other by means of one or more surfactants. . The droplet size is significantly smaller than that of an ordinary emulsion, and as a result, a microemulsion, in contrast to an ordinary emulsion, is transparent. The formation of microemulsions requires no special measures, apart from the limited amount of energy required to mix the components. * They form spontaneously as soon as the different components are brought together.

By sparingly soluble in water it is meant here that only 30 very minor amounts dissolve in water, i.e. less as 25 wt%, preferably less as 10 wt%.

The fuel mixture according to the invention has the following advantages: a. It is clear; 35 b. requires little or no stirring energy during preparation; c. is stable to at least -20eC; d. is non-corrosive and does not affect the paint layer; e. does not swell or attack plastics; 8005581 * - r \ 4 f. gives less emission of harmful components in the exhaust gases like petrol; g. gives good knock resistance so that the addition of tetra-alkyl lead as an octane booster is not necessary.

In particular, it has been found that in addition to small amounts of these higher water insoluble or sparingly soluble alcohols, a greater amount of fully water-soluble alcohols having 2-4 C atoms has the effect of requiring much less surfactants.

Another major advantage of the invention is that, without compromising the clarity and stability of the fuel mixture, the amounts of water-soluble alcohols and the water insoluble or only slightly soluble alcohols can be varied with respect to each other.

For example, the liquid mixture according to the invention may comprise: a. 5-20 wt.% Completely water-soluble alcohols with 2-4 C atoms and b. 0.01-5% by weight of water soluble or sparingly soluble alcohols with 4-12 20 C atoms.

Preferably, the completely water-soluble alcohol with 2-4 C atoms is tertiary butanol, together with the small amounts of insoluble or sparingly water-soluble alcohols.

Most preferred is the addition or use of larger amounts of insoluble or sparingly water-soluble alcohols with 4-12 carbon atoms. As a result, the amount of surfactants can be reduced, while at the same time an increase in the stability patch is found. For example, the most preferred mixture contains 5-20 wt-2 of insoluble or little water-soluble alcohols with 4-12 carbon atoms.

Preferably the insoluble or sparingly water-soluble alcohol with 4-12 carbon atoms is n-butanol or n-pentanol. The amount of water-insoluble alcohols with 4-12 C atoms in the above liquid mixture is preferably 5-15% by weight.

8005581 «5

The mixture may additionally contain 0.01-5% by weight of completely water-soluble alcohols with 2-4 C atoms.

As mentioned earlier, the amount of water and methanol in the liquid mixture can be varied with respect to each other.

Preferably, the liquid mixture contains 1-5% by weight of water and 2-15% by weight of methanol.

Surfactants are required to disperse the water and the alcohols in the gasoline, whereby the applicant believes that a micro-emulsion is obtained. Preferably anionic or nonionic surfactants and in particular combinations thereof are used. A mixture of surfactant acids and salts of these acids as surfactants are most preferred because they prove to be very suitable and are moreover inexpensive. The liquid mixture preferably contains 0.1-10% by weight surfactants. The quantity is simple to determine by the person skilled in the art. If a non-clear emulsion is formed, the amount must be increased.

Suitable anionic surfactants are: 20 - salts of surfactant carboxylic acids, in particular fatty acids with 10 to 20 carbon atoms; sulfuric acid esters, in particular alkyl esters with an alkyl group of 10 to 20 carbon atoms; alkyl and alkylaryl sulfonates, the alkyl group having 10 to 20 C-25 atoms and the alkylaryl group having 10 to 26 C atoms; - petroleum sulfonates, lignin sulfonates; phosphoric acid esters, in particular alkyl esters with an alkyl group of 10 to 20 carbon atoms; - salts of surfactant phosphorous and phosphoric acids.

The following may be considered as nonionic surfactants: - ethylene oxide condensation products with, for example, alcohols with 6 to 18 carbon atoms, alkylphenols, polyols or propylene oxide; polyhydroxy compounds such as esters of polyols and fatty acids; 35 - fatty acids both saturated or unsaturated with 10 to 20 C atoms.

8 0 0 5 5 8 1 * »6

It is a great advantage of the present invention that it is possible to directly use a mixture obtained in the preparation of methanol from methane, without having to remove water and higher alcohols.

A mixture of methanol, water and sparingly or sparingly water-soluble alcohols can be obtained directly by catalytic steam reforming of methane and subsequent catalytic synthesis of the resulting gas mixture, without subsequent purification, such as removal of water and higher alcohols. The resulting mixture is extremely suitable for dispersing in petrol with the aid of surfactants and possibly a higher alcohol, whereby a mixture is obtained which remains clear and stable over a wide temperature range (-20 ° C to + 30 ° C). The resulting mixture contains 10-25% by volume of water and 0.05-0.5% by volume of methanol, or higher alcohols, based on methanol.

It is possible according to the invention to incorporate the mixture of methanol, water and higher alcohols into hydrocarbons without further ado with surfactants, although it is advantageous to add an additional amount of alcohol with 2 to 12 carbon atoms, because as a result the required amount of surfactants may be less. Preferably 5-20 wt.% Of these alcohols are added.

To further improve the stability of the resulting clear liquid mixture, the mixture may additionally contain an ether with 2-8 C atoms, in particular methyl tertiary butyl ether. The water-insoluble alcohol can be partially replaced by the aforementioned ether. 0.01 to 15% by weight, in particular 0.05-10% by weight, of ether is preferably added.

Example I

30 Clear liquid mixtures were formulated by placing in a test tube:

Premium gasoline; (RON * 99; MON * 88; boiling range 35 to 200 ° C); methanol in the form of crude methanol with 21.5 vol.-Z water and 0.02 vol.-Z insoluble or sparingly water-soluble alcohols, such as butanol, pentanol and higher alcohols, and 0.08 vol.-Z completely water-soluble alcohols, such as ethanol and propanol; or pure methanol with 21.5 vol.-Z water; 8005531% r 7 a mixture of Na oleate and oleic acid in the ratio 80:20 and n-butanol.

The surfactant mixture was dissolved in the alcohol mixture and added as such to the gasoline.

The amounts of the different ingredients are listed in the following table, also indicating whether the mixture is stable after 1 day storage at -20 ° C.

Mixtures at -20 * 0

Super petrol Na oleate n-butanol Pure Raw Stability

in oleic acid MeOH * MeOH * at -20 ° C

(80: 20) 21.5 vol% h2o ml_gr_gr_gr_gr_ 10 (* 7.4 gr) 1.00 0.50 1.20 - phase separation 15 10 1.00 0.50 - 1.20 clear 10 0.75 0 .75 1.20 - phase separation 10 0.75 0.75 - 1.20 clear * MeOH methanol.

The same results are obtained with 1.00 g of methanol (pure and crude).

Furthermore, it appears that upon addition of crude methanol from 0.75 to 1.75 g, a clear mixture is obtained at both surfactant-butanol ratios. It has further been found that the stability range is twice as great as when using pure methanol with 21.5% by volume of water.

Example II

To demonstrate the effect of different types of alcohol on the stability of the clear liquid mixture according to the invention, the amounts in grams of each type of alcohol at 8005531 are 8 + 20 ° C, respectively. -20eC to be added to obtain a clear stable liquid mixture determined.

The mixture contains 10 ml of normal petrol (RON 88; MON 82), 0.8 g of ammonium oleate-oleic acid mixture in the ratio 60: 40; and 1.8 g of crude methanol of the composition as in Example I.

+ 20 ° C-20 ° C Solubility in water Iso-propanol 1.51 g. ineffective Fully soluble n-propanol 1.35 "2.25 gr.

tert. butanol 1.23 M 1.79 "10 iso-butanol 1.10" 1.60 "Insoluble n-butanol 0.98" 1.30 "n-pentanol 0.90" 1.12 "

These results show that the insoluble alcohols, in particular n-butanol and n-pentanol, clearly have the greatest effect.

Example III

In this example, the effect of the addition of methyl tertiary butyl ether (MTBE) on the stability of the liquid mixtures according to the invention is demonstrated.

20 The results are shown in the table below.

A mixture of normal gasoline surfactants and crude methanol as in Example II was started.

8005531 9

Gasoline NH4 * oleate “n-butanol MTBE crude MeOH Stability (normal) Oleic acid (60; 40) SE_§Ξ__8r 8r_ 5 7.27 * - - 0.5 ** 1.81 Unstable

7.27 0.80 1.20 - 1.81 Stable up to + 10 ° C

7.27 0.80 1.20 0.5 1.81 Stable down to -20 ° C

* = 10 ml ** »0.625 ml.

8005531

Claims (16)

10 3233 A clear liquid mixture for use as a fuel in combustion engines comprising: a) a liquid hydrocarbon mixture; b) water; C) a water-completely soluble alcohol; d) surfactants; characterized in that the fuel mixture consists of: a) a liquid hydrocarbon mixture; b) 1-10 wt-Z water; C) 0.1-25 wt% methanol as fully water-soluble alcohol; d) 0.1-15 wt.% surfactants and e) 0.01-20 wt. 2 insoluble or sparingly water-soluble alcohols with 4 to 12 carbon atoms. The clear liquid mixture according to claim 1, characterized in that the liquid mixture contains: 0.01-5 wt.% W / w insoluble or water-soluble alcohols with 4-12 carbon atoms and additional 5-20 wt-% completely water-soluble alcohols with 2-4 C atoms. Clear liquid mixture according to claim 2, characterized in that the completely water-soluble alcohol with 2-4 C atoms is tertiary butanol. 4. Clear liquid mixture according to claim 1, characterized in that the mixture contains 5-20% by weight of water-insoluble or slightly water-soluble alcohols with 4-12 carbon atoms. Clear liquid mixture according to claim 4, characterized in that the mixture additionally contains 0.01-5% by weight of completely water-soluble alcohols with 2-4 C atoms. 6. Clear liquid mixture according to claim 4, characterized in that the insoluble or sparingly water-soluble alcohol with 4-12 carbon atoms is n-butanol or n-pentanol. Clear liquid mixture according to claims 4 and 6, characterized in that the liquid mixture contains 5-15 wt.% Insoluble or sparingly water-soluble alcohols with 4-12 carbon atoms. 8005531 * The clear liquid mixture according to claim 1, characterized in that the mixture contains 1-5% by weight of water. Clear liquid mixture according to claim 1, characterized in that the mixture contains 2-15% by weight of methanol. Clear liquid mixture according to claim 1, characterized in that the mixture contains a combination of anionic or nonionic surfactants. 11. Clear liquid mixture according to claim 10, characterized in that the mixture contains surfactant acids and salts of these acids as surfactants. The clear liquid mixture according to claim 1, characterized in that the mixture contains 0.1-10% by weight of surfactants. 13. Clear liquid mixture according to claim 1, characterized in that the mixture of methanol, water and water-insoluble alcohols is obtained by steam reforming of methane, and then catalytic synthesis of the resulting gas mixture. A clear liquid mixture according to claim 13, characterized in that the mixture additionally contains 5-20% by weight of an alcohol with 2-12 carbon atoms. Clear liquid mixture according to one or more of the preceding claims, characterized in that the mixture additionally contains 0.01-15% by weight of ether. 16. Clear fluid mixture as substantially described and illustrated in the examples. MHP / TS 8 0 0 5 5 3 1