DE1127141B - fuel - Google Patents

Description

GERMAN

PATENT OFFICE

S 63681 IVc / 46a «

REGISTRATION DAY i

NOTICE
DES REGISTRATION
AND ISSUE OF
EDITORIAL:

June 29 , 1959

APRIL 5, 1962

In modern gasoline engines with high compression ratios, in addition to the usual, from If the octane number of the fuel is too low, there are other combustion irregularities some of which are also noticeable through noises, but not through an increase in the octane number of the fuel can be eliminated. An irregular ringing is observed, which indicates overheating the precipitation in the combustion chambers and a pre-ignition caused by it should be based. Another engine noise that mainly occurs at high speeds and occurs in the range of medium to high loads, is referred to as "chatter" and is similar to this Noise that occurs when you stroke a picket fence with a broomstick. One takes indicate that this "rattling", which is particularly intense in the range of low frequencies between about 400 and 1500 Hz occurs from a vibration of power transmitting machine parts such as connecting rods and Crankshafts, as a result of excessive pressure increase during the combustion of the fuel-air mixture originates. The rattling noise becomes more pronounced with an increase in concentration noticeable of aromatic hydrocarbons in the fuel, so that its fight always is gaining in importance, as it is well known that modern refining processes are increasing Dimensions of fuels with high aromatic content can be produced.

Even with so-called »hot starting«, i. H. when restarting an engine that is still hot, pedal annoying engine noises, which probably result from an early ignition of the fuel-air mixture the high temperature of the engine block, the presence of deposits in the ignition chambers, the short piston travel when starting and the tendency of the fuel to spontaneously ignite are based.

A fuel suitable for gasoline engines with high compression ratios should not only be behave as advantageously as possible with regard to the combustion irregularities discussed above, but it should also have only a slight tendency to form precipitates in the combustion chamber themselves and in the entire supply system as well as, if possible, the electricity conduct so that an electrostatic charge and thus the formation of sparks is avoided.

It has now been shown, surprisingly, that fuels based on hydrocarbons fuel

Applicant:

Shell Internationale Research Maatschappij N.V., The Hague

Representative: Dr. K. Schwarzhans, patent attorney, Munich 19, Romanplatz 9

Claimed priority: V. St. v. America July 1, 1958 (No. 745 837)

Douglas Graeme Roddick, Lafayette, Calif.

(V. St. Α.), And Lawrence Bruce Scott, Chester, Cheshire

(Great Britain) have been named as inventors

or hydrocarbon mixtures in the boiling range of liquid gas and gasoline in the sense of the above Discussions can be greatly enhanced if you consider them as fuel ingredients dialkyl ethers known per se and organic phosphorus compounds of certain constitution in the following specified proportions incorporated. The fuels according to the invention also contain of the hydrocarbon component 2 to 50 percent by volume, based on the mixture of the base fuel and dialkyl ethers, a dialkyl ether having at least one branched chain alkyl group and 4 to 8 carbon atoms and 0.001 to 0.1 percent by weight, based on the total mixture, one in Hydrocarbon soluble organic phosphorus compound with the formula

P (X) _a (XR) ₆ (R) _c

in which X is an oxygen or sulfur atom, R is a monovalent organic radical which contains no other atoms except carbon, hydrogen and halogen and 1 to 10 carbon atoms, a - 0 or 1 and b and c are integers from 0 to 3 inclusive, where the sum of b + c - 3.

209 558/246

Ethers which do not have the listed composition are for the purposes of the present Invention not useful. For example, dialkyl ethers that do not have at least one alkyl group with a branched chain have an octane number that is far too low. Furthermore, ethers would have which contain less than 4 carbon atoms and more than 8 carbon atoms, not for the purpose volatility suitable for the invention. It is preferred to use ether with 5 or 6 carbon atoms too use, where at least one of the two carbon atoms and expediently both carbon atoms, which are bound to the only oxygen atom of the ether, a secondary or a tertiary Represent carbon atom. Within this preferred group of dialkyl ethers give methyl tertiary butyl ethers and in particular diisopropyl ether, particularly favorable results. Others under the Invention suitable ethers are z. B. ethyl tert. butyl ether, Isopropyl sec. butyl ether, isopropyl tert. butyl- 20 phosphate, tris- (3,3,5-trimethylcyclohexyl) -phosphate, ether, methyl tert. amyl ether, ethyl isopropyl ether, tris (2-chloropropyl) thionophosphate, diphenyl cresyl methyl sec. butyl ether and methyl tert. hexyl ether.

A commercially available diisopropyl product, which is a subordinate product, is very particularly favorable Contains amount of isopropyl alcohol and by the reaction of propylene and water in a sulfuric acid medium, z. B. according to the manufacturing method described in the USA patents 2055720 or 2178186, is obtained. A typical one

Product contains a high concentration of di-iso, at least 4 percent by volume. Ether propyl ether, a smaller amount of isopropyl alcohol, concentrations above 50 percent by volume are no smaller amounts of ethyl isopropyl ether, ethyl only superfluous, but also have a _{harmful effect on various alcohol, C 6} to C ₁₂ propylene polymers and water. It is preferred that no and in some cases small amounts of C ₂ to more than 25% and more suitably no more than C ₄ hydrocarbons. Below there will be ana- 35 17 volume percent ether in the fuel mixture of such commercially available products. Particularly preferred ether concentrations indicated: are in the range of about 6 to 15 percent by volume,

based on the mixture of base fuel and Dialkyl ethers.

The phosphorus compound should preferably be in a concentration of at least 0.01 percent by weight be contained in the fuel. It is particularly desirable that no more than 0.06 percent by weight be present are. In the presence of a lead anti-knock agent such as tetraalkyl lead, e.g. B. tetraethyl lead, may the concentration of the phosphorus-containing compound is not less than 0.05 theoretical units and not greater than 0.6 theoretical units. Preferred concentrations for the phosphorus-containing compound are at least 0.2 theoretical units and not more than 0.4 theoretical units. A »theor. Unity «means in the context of the present invention that the amount of phosphorus compound with the lead in the

contain) and in particular cyclic hydrocarbon radicals, such as alkylaryl groups. If so desired but each radical can also contain a halogen atom. In this case, the halogen atom is preferable Chlorine or bromine. It is appropriate that at least one of the monovalent radicals is at least 4 and in particular has at least 6 carbon atoms. The trialkyl hydrocarbon phosphates are particularly suitable, Phosphites and phosphines, which ίο each contain 3 hydrocarbon residues.

In the fuels according to the invention, for. B. contain the following phosphorus-containing compounds be: tricresyl phosphate, tributyl phosphate, tributyl phosphite, diphenyl cresyl phosphate, triphenyl phosphate, Octyl diphenyl phosphate, triamyl thionophosphate, triphenyl phosphine, trimethyl phosphine oxide, Tris (2-propyl) phosphite, bis (2-propyl) -2-propyiphosphonate, trimethyl phosphate, trimethyl phosphite, Phenyldimethylphosphinate, propyldicresylthiolo-

phosphonite, dimethylxylyl phosphate, dimethyl cresyl phosphate, ethyldimethylthiophosphinite, dimethylphenyl phosphate and dimethyl phenyl phosphonate.

It is crucial to obtain a good technical effect that a suitable choice regarding the concentration of both ether and phosphorus compounds.

The concentration of the dialkyl ether should be preferred

Diisopropyl ether
Isopropyl alcohol

Ethyl isopropyl ether

Ethyl alcohol ..

₉ H ₁₈
C ₁ ^ H ₂₄

Weight percent C. D. A. B. 85.9 89.1 97.6 98.1 4.7 7.7 1.1 1.0 0.3 «U <0, l <0, l 0.5 0.2 0.5 0.5 1.2 2.2 0.4 3.0 0.6 <0, l - 3.8 <0, l } 0.2 0.6 0.2 <0, l 0.2

85.3 12.2

0.1 0.2

1.1 0.2

0.1 1.0

The organic phosphorus-containing compounds suitable for use in the mixtures according to the invention

Lead antiknock agent of the mixtures is stoichiometrically equivalent. This means that all lead atoms and all phosphorus atoms are present in the same ratio as in the compound Pb ₃ (PO ₄ I _2. In a certain fuel mixture, which contains a lead anti-knock compound and a phosphorus-containing compound

Compounds must be soluble in hydrocarbons. Contains 60 compound, z. B. be the number. It can be a phosphine, phosphine T _p = theoretical units of the existing phosphine

oxide, phosphite, phosphonite, phosphinite, phosphate, phosphorus-containing phosphonate, phosphinate or a sulfur homologous formula:

be about this. The organic residue or residues

in the phosphorus-containing compound can be an alkyl 65 _ _r

(cyclic or acyclic) or an aryl group. Al

Preferably they are hydrocarbon residues (i.e.

Radicals containing only carbon and hydrogen atoms in which Mp is the number of gramsol of phosphorus

p connection, from the following

containing compound and Al is the number of gram atoms of lead in the lead anti-knock agent.

The base liquid of the fuel mixture according to the present invention can be a gasoline, which can have been obtained by direct distillation, thermal or catalytic cracking or thermal or catalytic reforming. The base liquid can also be a product obtained by alkylating low molecular weight olefins and isoparaffins, e.g. B. of butylene and isobutane. The hydrocarbon in question or the mixture of hydrocarbons can have a wide boiling range, e.g. B. starting from the boiling point of C ₃ - to C ^ hydrocarbons up to 235 ° C, preferably from 25 to 220 ° C and very particularly useful from 35 to 190 ° C.

Since, given the multiplicity of interlocking processes, it is somewhat difficult to find the Investigating individual combustion irregularities separately was described below for those Comparative experiments used an energy test that is largely adapted to the behavior in practice.

One puts the gasoline engine of a motor vehicle under gradual at a set speed increasing load in operation and increases the opening of the throttle valve until abnormal combustion noises occur. After reaching the state of equilibrium the formation of deposits in the engine is measured at the time of occurrence Such noises reduce the braking energy on the rear wheels of the vehicle concerned. The one in the The test results summarized in the table below were used on the latest design of automobile engines obtained with a compression ratio of 9.5 to 10.5 (engine speed: 2500 rpm).

Type of fuel

1. Gasoline + 2 to 3 ecm of tetraethyl lead per
3.7851 (street octane number: 98 to 100)
= Fuel A

2. Fuel A + 5 to 10 percent by volume
Diisopropyl ether or methyl tert. butyl ether (street octane number: 99 to 102)

3. Fuel A + 0.3 theoretical units of tricresyl phosphate

4. Fuel A + 5 to 10 percent by volume
Diisopropyl ether + 0.3 theoretical units
Tricresyl phosphate

Braking energy in PS

35 to 50

35 to 50 75 to 80

85 to 90

It is evident, then, that the ether, which by itself under the given conditions does not have any beneficial effect exerted in the presence of phosphorus-containing compounds of the invention Kind of a significant advantage over the effects like those with the phosphorus-containing compound be achieved alone, results.

A very interesting point in evaluating the propellants according to the invention is that The ether and the phosphorus compound also work together synergistically to provide an improved Engine cleanliness and a favorable distribution of the high-boiling components of the gasoline and the non-volatile additives between the individual cylinders to achieve. The phosphorus-containing compounds in question have boiling points that are in comparison are relatively high compared to the average value of gasoline. Besides, its viscosity is also relatively high. On the other hand, the ether component is a better solvent for resins and other resinous deposits, as they occur in gasoline engines, as the usual hydrocarbon components, especially the non-aromatic

ίο Components of the gasoline. If you have an engine which is operated with a fuel according to the present invention starts, so is the feed line relatively cool, and a considerable amount of the ethers separate in the form of a liquid phase on the walls of the supply line. The phosphorus compound softens or plasticizes every existing precipitate and thus makes it easier for the ether to wash away the precipitate into the liquid, whereby the precipitates are entrained into the combustion chamber and burned there will. Subsequently formed precipitates, which with prolonged operation of the engine under normal Operating temperatures can occur, are then in during the next warm-up period of the engine Solution transferred.

The improved distribution effect of the combination of ether and phosphorus-containing compound is based on the increased tendency of the liquid phase of the high-boiling components of the gasoline, on the walls crawl along the feed line towards the combustion chamber. When the fuel-air mixture leaving the carburetor and entering the supply line, it is partially in vapor form and partly in the form of finely divided droplets. A significant proportion of these droplets collects as a liquid phase on the walls of the supply line. When this liquid phase turns into Moved towards the combustion chamber, further low-boiling components evaporate therefrom. The relatively non-volatile phosphorus compound in the fuels according to the invention now has a higher surface tension than most of the gasoline, during the quite volatile ether has a lower surface tension than the bulk of gasoline. It exists thus a positive gradient of the surface tension in the direction from the carburetor to the combustion chamber. It has been found that under such circumstances a liquid phase tends to reverse crawl of gravity. The component of force that moves the liquid film against gravity moved is directly proportional to the difference between the surface tensions of those components which evaporate from the liquid film, and the remaining high-boiling components.

Have the ethers according to the group described

generally much lower surface tension than gasoline hydrocarbons. For example, the surface tension of diisopropyl ether at 25 ⁰ C 17.5 dyn / cm (Vogel, AIJ Chem. Soc, Part 1, p 616 [1948]) compared with about 26 dynes / cm for gasoline hydrocarbon. The addition of both the ether and the phosphorus-containing compound to gasoline hydrocarbons thus increases the gradient of the surface tension of the liquid along the walls of the supply line quite considerably and thus increases the mobility of the liquid. This leads to a better distribution of the high boiling point

it components of gasoline and additives with lower volatility between the cylinders.

The fuel mixtures according to the invention have another important property, namely theirs extraordinary and surprisingly low tendency to form electrical charges. It is found have been that the ethers and the phosphorus-containing compounds in this regard in an unexpected way under Work together to increase the electrical conductivity of the gasoline. This results e.g. B. from the following Tabel:

Type of fuel

1. Base fuel

2. Base fuel + 3 ecm tetraethyl lead per 3.785 1

3rd base fuel + 0.3 g tricresyl phosphate per 3.785 1

4. Base fuel + 10 percent by volume diisopropyl ether

5. Base fuel + 0.3 g of tricresyl phosphate per 3.7851 + 10 percent by volume Diisopropyl ether

Electric conductivity

15th

17 · ΙΟ- ¹ * 15 · ΙΟ " ¹⁴ 19 · 10-" 27 · ΙΟ- ¹ *

37 · ΙΟ- ¹⁴

_25th

In addition to the ether and the phosphorus-containing compound, the fuel according to the invention contains preferably a lead anti-knock agent in a suitable concentration, e.g. B. a tetraalkyl lead compound, like tetraethyl lead. The concentration of the lead anti-knock agent is preferably at least 0.5 ecm to 3.7851 and up to 6 ecm to 3.7851. The amount is expediently at least 1 ecm to 3.7851 and not more than 3 ecm to 3.7851. When a If lead anti-knocking agent is used, a halogenated hydrocarbon rinsing agent is preferably used in combination with this, such as ethylene dibromide or a mixture of ethylene dibromide and ethylene dichloride, added, expediently in an amount of 1.0 to 1.5 or 1.6 theoretical units, where 1.0 theoretical unit is the amount required to make 2 atoms Halogen for 1 atom of lead in the lead anti-knock agents are available. In the mixtures according to the invention other anti-knock agents can also be used, such as iron carbonyl, dicyclopentadienyl iron, xylidine, N-methylaniline, and the organo-manganese compounds. especially methylcyclopentadienyl manganese tricarbonyl or bis (cyclopentadienyl) manganese.

Other additives that can be used if desired are, for. B. the various anti-ice agents, such as NC ₁₂ -i ₈ -alkylpropylenediamine and dimethylformamide; Means for changing the type of precipitate in the combustion chamber, glycol esters of boric acid, e.g. B. Isopropyl 2-methyl-2,4-pentanediol borate, 2-methyl-2,4-pentanediol monoborate, bis (1,1,3-trimethyltrimethyleneoxy) boric acid, antioxidants such as N, N'-di- sec.butylphenylendiamii ?, 2,6-di-tert. butyl-4-methylphenol, 4,4'-methylene-bis (2,6-di-tert-butylphenol); Corrosion inhibitors such as polymerized linseed oil acids and N, C-disubstituted imidazolines; Metal deactivators, N, N'-disalicylal-1,2-propanediamine; Dyes and silicone oils.

A particularly suitable example of a fuel mixture according to the invention is the following:

1. Petroleum benzine hydrocarbons 90 percent by volume

Diisopropyl ether (commercial product that is made by reacting of water and propylene, as described above as "D") 10 percent by volume

Tetraethyl lead 2.8 ecm per 3.7851

Ethylene dibromide ... 0.5 theoretical units

Ethylene dichloride 1.0 theoretical unit

Tricresyl phosphate 0.3 theoretical units

(ie 0.38% by weight) NC ₁₂ -alkyl-1,3-propanediamine 0.003 percent by weight

N, N'-di-sec-butylphenylenediamine 0.0005 percent by weight

This mixture had an octane number of 102.0 according to the ASTM research method (Wiese scale or isooetane + 0.16 ecm tetraethyl lead per 3.7851), an ASTM octane number according to the engine test method of 92.5 or a boiling range according to ASTM distillation of 38 to 204 ° C.

Other examples of Propellants specified according to the invention:

2. Petroleum Zinc Hydrochloric

fabrics

Methyl tert-butyl ether ...

Tetraethyl lead

Tributyl phosphate

3. Petroleum Benzine Hydrochloric

fabrics

Diisopropyl ether

Tricresyl phosphate

4. petroleum benzin hydrocarbons;

Diisopropyl ether

Tetraethyl lead

Octyl Diphenyl Phosphate ..

5. Petroleum Benzine Hydrocarbons

Isopropyl tert-butyl ether

Tetraethyl lead

Dimethylxylyl phosphate ...

6. Petroleum Zinc Hydrocarbons -

Diisopropyl ether

Tetraethyl lead

Tributylphosphine

7. Petroleum Zinc Hydrochloric

fabrics

Methyl tert-butyl ether ...

Tetraethyl lead

Tris (2-chloropropyl) thione phosphate

8. Petroleum Benzine Hydrocarbons

Ethyl tert-butyl ether

Tetraethyl lead

Methylcyclopentadienyl manganese tricarbonyl

Tricresyl phosphate

85 percent by volume 15 percent by volume 3 ecm per 3.7851 0.2 theoretical units

80 percent by volume 20 percent by volume 0.02 percent by weight

88 percent by volume 12 percent by volume 2 ecm per 3 ^ 785 0.2 theoretical units

95 percent by volume 5 percent by volume 2.5 ecm per 3.7851 0.15 theoretical units

90 percent by volume 10 percent by volume

2.5 ecm per 3.7851 0.10 theoretical units

91 percent by volume 9 percent by volume 2.8 ecm per 3.7851

0.1 theoretical units

85 percent by volume 15 percent by volume 3.0 ecm per 3.7851

0.1 g manganese per

3.7851

0.3 theoretical units

9. Petroleum Zinc Hydrocarbons 96 percent by volume

Diisopropyl ether 4 percent by volume

Tetraethyl lead 3 ecm per 3.7851

Tricresyl phosphate 0.4 theoretical units

10. Petroleum benzine hydrocarbons 92 percent by volume

Isopropyl tert. amyl ether 8 percent by volume

Tetraethyl lead 2.4 ecm per 3.785 1

Diphenyl cresyl phosphate .. 0.12 theoretical units

11. Petroleum Zinc Hydrochloric

fabrics 85 percent by volume

Diisopropyl ether 15 percent by volume

Lead tetraät hyl 3 ecm per 3.7851

Tris (2-propyl) phosphite. 0.2 theoretical units

12. Petroleum Benzine Hydrocarbons 88 percent by volume

Diisopropyl ether 12 percent by volume

Tetraethyl lead 2.8 ecm per 3.7851

Tris (2-propyl) phosphite .. 0.1 theoretical units

Tricresyl phosphate 0.1 theoretical units

13. Petroleum Zinc Hydrochloric

Methyl tert. butyl ether ... 15 percent by volume

Tetraethyl lead 2.5 ecm per 3.785 l

Tricresyl phosphate 0.3 theoretical units

14. Petroleum Benzine Hydrocarbons 75 percent by volume

Diisopropyl ether 25 percent by volume

Tetraethyl lead 2.5 ecm per 3.785 1

Dimethyl cresyl phosphate .. 0.8 theoretical units

Dimethyl xylene phosphate. 0.08 theoretical units

15. Petroleum benzine hydrocarbons 93 percent by volume

Diisopropyl ether 7 percent by volume

Tetraethyl lead 2.7 ecm per 3.7851

Tricresyl phosphite 0.3 theoretical units

Claims (10)

PATENT CLAIMS: 1. Fuel based on a hydrocarbon or hydrocarbon mixture boiling within the gasoline and liquid gas boiling range, characterized by a content of a dialkyl ether known per se as a fuel component with at least one alkyl group with a branched chain and 4 to 8, preferably 5 to 6 carbon atoms, in quantities from 2 percent by volume to 50 percent by volume, based on the mixture of the base substance and dialkyl ether, as well as a content of an organic phosphorus compound known per se as a fuel component and soluble in hydrocarbons with the formula: P (X) »(XR) ₆ (R) _e in which X is an oxygen or sulfur atom, R is a monovalent organic radical which contains no other atoms except carbon, hydrogen and halogen and 1 to 10 carbon atoms, o = 0 or 1 and b and c are integers from 0 to 3 (inclusive), where b + c == 3, in amounts of 0.001 to 0.1 percent by weight, based on the total mixture. 2. Fuel according to claim 1, characterized in that that the two carbon atoms bonded to the oxygen atom in the dialkyl ether are secondary or are tertiary carbon atoms. 3. Fuel according to claim 1 or 2, characterized in that the dialkyl ether is methyl tert-butyl ether or diisopropyl ether. 4. Fuel according to claim 1 to 3, characterized by a dialkyl ether content of 4 to 25 percent by volume, preferably from 6 to 15 percent by volume. 5. Fuel according to claim 1 to 4, characterized in that the phosphorus compound is hydrocarbon radicals, preferably contains cyclic hydrocarbon radicals such as alkylaryl groups. 6. Fuel according to claim 1, characterized in that the monovalent radical R in the phosphorus compound contains at least 4 carbon atoms, preferably 6 carbon atoms. 7. Fuel according to claim 5 or 6, characterized in that the phosphorus compound is a Phosphoric acid esters with 3 hydrocarbon radicals, such as tricresyl phosphate, or a phosphite or Is phosphine with 3 hydrocarbon residues. 8. Fuel according to claim 1 to 7, characterized by a content of the phosphorus compound from 0.01 to 0.06 percent by weight. 9. Fuel according to claim 1 to 8, characterized by an additional content of a lead anti-knock agent, such as tetraalkyl lead, for example tetraethyl lead, and a content of the phosphorus compound from 0.05 to 0.6, preferably 0.2 to 0.4 theoretical units. 10. Fuel according to claim 1 to 9, characterized in that the base fluid a in the range of 25 to 22O ⁰ C, preferably from 35 to 190 ° C boiling hydrocarbon mixture, preferably a gas, such as a directly distilled, a thermally or catalytically cleaved or a thermally or catalytically reformed gasoline. Considered publications: German patent application N 4011 IVc / 46a ^e (published on June 18, 1953); German interpretation K 15974 IVc / 46a ⁶ (published October 18, 1956);
Austrian Patent No. 185 010; French Patent Nos. 1043 087, 1060 469, 581; Belgian patents Nos. 523 150, 530 652; British Patent Nos. 445 503, 504 837, 507 246; Chemisches Zentralblatt, 1955, p. 2571 (C. O. Tougberg etc.). Older patents considered: German Patent No. 1,051,566. © 209 558/246 3.62