DE1262669B - Leaded fuels for gasoline engines - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

ClOl

German class: 46 al ^ -ΐ ·· <'// Z b

Number: 1262 669

File number: St 21828IV d / 46 a6

Filing date: May 3, 1962

Opening day: March 7, 1968

It is known from US Pat. No. 2,794,717 that the addition of phosphorus sesquichalcogens to gasoline reduces self-ignition (surface ignition) caused by deposits and protects lead alkyl anti-knock agents against the adverse effects of oxidative deterioration. Phosphorus sesquisulfide, however, has a significant adverse effect on the octane number. This adverse effect was discussed in a paper presented by Gunderloy and N eb 1 e 11 at the meeting of the American Chemical Society, Petroleum Chemistry Division, Cleveland, Ohio, April 5--14, 1960. The preprint of this publication (p. 76, Fig. 1) shows that the presence of 1.0 T (3 theoretical units) of phosphorus in the form of P4S3 in a gasoline containing 0.65 ecm of tetraethyl lead per liter, the engine octane number by 6 units and the research octane number by almost 5 ¹ ^ units. Since high demands are made on the octane number of most of the gasolines on the market today, the lowering of the octane number means that the P4S3 is unsuitable as an additive for commercially available gasoline.

It has now been found that the combustion properties of lead-containing hydrocarbon fuels boiling in the gasoline range, ie fuels for gasoline engines, can be improved by giving them 0.01 to 2.00 theoretical units of phosphorus in the form of one of P-1S3 and one Extract of a reaction product obtained from a clarified circulating oil and optionally a small amount of zinc naphthenate and / or alkali hydroxide is added. Preferably, the phosphorus in the form of a reaction product is added from P4S3 and an extract from such a purge cycle oil boiling and in the range of about 205-538 ⁰ C contains at least 50% of the carbon atoms in the form of aromatic compounds. Such lubricating oils are especially preferably used, boiling in the range 288-400 ⁰ C.

The clarified circulating oils are used as soil residues when fractionating the output obtained from catalytic cracking processes. The extract from the clarified circulating oils is a preferred one Product because the circulating oils are available in considerable quantities and hardly any others Has uses other than reintroduction into the catalytic cracking process. Since the extract is highly aromatic, it is relatively heat-resistant and can be lead-containing under normal heat Fuels for gasoline engines

Applicant:

The Standard Oil Company,

Cleveland, Ohio (V. St. A.)

Representative:

Dr.-Ing. Dr. jur. F. Redies, Dr. rer. nat. B. Redies and Dr. rer. nat. D. Türk, patent attorneys, 4000 Düsseldorf-Benrath 3,
Erich-Ollenhauer-Str. 7th

Named as inventor:

John M. Musselman, Brecksville, Ohio; Oliver A. Kiikka, Willoughby, Ohio (V. St. A.)

Claimed priority:

V. St. v. America May 19, 1961 (111139)

and pressure conditions do not crack well. For this reason it is desirable to use the extract if possible not to reintroduce them into the catalytic cracking process.

Processes for making extracts from clarified circulating oils are known and need to be mentioned only briefly here, since these processes as such do not form part of the invention.

After the crude oil has been separated by simple distillation into several crude products, which is within 260 to 320 ° C up to about 540-600 ⁰ C fraction boiling a catalytic cracking process usually subjected. The products obtained in the cracking apparatus are then fractionated and divided into a part leaving the upper end of the column, one or more parts leaving the side and the residues. Regardless of which system working with catalysts is used in the cracking plant, considerable amounts of the powdered catalyst are transferred from the cracking device to the fractionation device, where they end up in the residues.

In general, the residues are separated from the catalyst by known clarification processes, then back into the cracking apparatus

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guided and subjected to the cracking process again. As a result of this known reuse the expressions "circulating oils" and "clarified circulating oils" were formed.

In recent times, there are new uses for the clarified circulating oils and special their paraffinic constituents have been found. These new opportunities have to do with training an extractive treatment of the "clarified circulating oils" to remove the mainly aromatic ones Separate components (extracts) from the paraffins (raffinates).

Solvents such as furfural, phenol, Duosol (propane + cresol) and sulfur dioxide dissolve preferentially the aromatics and the naphthenes and can accordingly be used for extractive treatment of clarified circulating oils can be used. '

The starting material for the fuel additives used according to the invention are the highly aromatic Extracts from the clarified circulating oils are particularly suitable. You can do that too Clarified circulating oil with one coming out of the fractionation apparatus as a side stream Combine material before extracting the oil. The addition of substances with lower Molecular weights can be desirable in order to determine viscosity, pour point, or other properties to modify the oil.

Further details of the processes known per se for the production and extraction of Circulating oils can be found in the literature, e.g. See U.S. Patents 2,660,552 and 2,882,220. According to these patents, the extraction of the clarified circulating oil is carried out with the aim of Recovery of the raffinates and less of the extracts carried out.

It also follows from this that the new products according to the invention are cheap without any difficulties available starting materials can be produced. '

The clarified circulating oils can be cleaned before or after the extraction according to known methods, z. B. freed from wax, treated with acids or shaken out with clay. The distance The waxes can be desirable if the extract or its reaction product with P4S3 is to be stored or shipped at temperatures below the solidification temperatures of the waxes in question. The waxes can be removed by extraction with suitable solvents, such as ketones, or by mechanical means, e.g. B. by pressing and centrifuging can be carried out. The treatment with acids and / or with clay is used to improve the color of the extract and to Removal of asphaltic and / or resinous materials. The extract treated with clay will preferably freed from adsorbed water before it is used according to the invention.

The clarified circulating oil in the sense of the above is a complex composition Mixture of highly aromatic hydrocarbons and does not allow a clear chemical analysis to. The composition of the extract varies according to the composition of the starting oils and the process conditions used for distillation, cracking, fractionation, etc. For example, a typical Sample of an extract from a clarified circulating oil according to Shell-n-d-m regulations (Aspects of the Constitution of Mineral Oils, Van Nes et al, Elsevier Publishing Co., Inc., 1951, pp. 318 to 346) analyzed. The analysis is as an example for the starting products to be used according to the invention, not to be regarded as a limitation. The values of the analysis result from the following Table I.

Table I.

template

0 to

10%

10 to
20%

20 to
30%

30 to 40% 40 to
50%

50 to
60%

60 to
70%

70 to
80%

Specific weight...

d?> ° ^c , 8 ms / cc

Pour point, ⁰ C

Flash point, ⁰ C

Color D-155

Viscosity, 98.9 ⁰ C SSU
Viscosity, 43.3 ° C SSU

Viscosity weight constant

ⁿ D

Aniline point, ⁰ C

Total sulfur,
Weight percent ....

Total nitrogen,
Weight percent ...

Carbon as rings,
%

Carbon as

Paraffins,%

0.9901
0.9574
-3.9
168
2-32.2
48.6

0.996

1.5587
18.9

1.43
0.025

67.1

32.9

1.032
0.9972
+ 7.2
182
blue
35.3
80.8

1.047
1.5906
20.6

2.03
0.05
66.8

33.2

1.045 1.0122 + 12.8
204
green
36.5
105.1

1.065 1.6021 24.1

2.21
0.062

66.9

33.1

1.057 1.0239 + 18.5 196 2 39.61

1.06 1.6141 29.1

1.91 0.067

63.3

36.7 1,072
1.042

+21.1

232
2
44.98

1.075
1.6316

32.5

1.65
0.054

61.1

38.9

1.0591
+ 21.1
243
2.5
53.7

1.090
1.6495
35.0

1.63
0.047

58.4

41.6

1.0825
+ 15.6
251
4th
77.9

1.109
1.6690
33.3

1.83
0.062

57.6

42.4

+ 21.1
254
4th
107.6

1.76
0.063

1.08 0.055

continuation

template

Obis
10%

10 to

20%

20 to

30%

30 to

40%

40 to

50 to
60%

60 to

70%

70 to
80%

Carbon as
Aromatics,%

Carbon as
Naphthenes,%

Total rings per
molecule

Rings per mole,
aromatic

Rings per mole,
Naphthenes

C - atoms per molecule
Molecular weight ....

Probable
structure

The entire extract from the clarified circulating oil is expediently divided into 10% fractions as was done for the purposes of the aforementioned analysis. The boiling ranges for the different fractions can be seen from the following table II:

Table II

270

fraction (%) Boiling range ( ⁰ C) 0 to 10 322 to 331 10 to 20th 331 to 380 20 to 30th 380 to 388 30 to 40 388 to 401 40 to 50 401 to 441 50 to 60 441 to 457 60 to 70 457 to 473 70 to 80 473 to 478 80 to 90 478 to 487

For the purposes of the invention, all extracts from clarified circulating oils and their mixtures with sidestream materials of the fractionation device can be used as starting products for the production of the new additives through which the fuels are improved according to the invention, provided that the sidestream materials are within a range of about 200 to 550 ° C boil and at least about 50% of the C atoms present in them (analyzed according to the Shell ndm regulations) are in the form of aromatic compounds. These raw materials are reacted with P4S3 in order to obtain the additives for the improvement of light gasoline. Either the total mixture or a fraction of the total mixture or a mixture of different fractions can be reacted with P4S3. The factor limiting the use of the heavier fractions of the extract is that the machines in question do not, under the operating conditions in question, -C ₇

may be too heavily contaminated with carbon-containing residues.

The additives used in the fuels according to the invention are prepared by adding P4S3 to an extract of clarified circulating oil and preferably heating the mixture in an inert atmosphere. The heating time is between about ¹ Iz to 24 hours. The reaction temperature is about 32 ~ 320 ⁰ C. In the aforementioned manner can be bis (calculated on the weight of the extract) to about 25 weight percent P4S3 implemented.

As already mentioned, the extract can be treated with clay and / or de-waxed before the implementation with P4S3 takes place.

The reaction product can be filtered with or without the use of filter aids. Additional treatments of the reaction products are possible and depend, among other things, on what the fuels modified with the reaction products are to be used for. if the reaction products are stored, they discolor under the influence of sunlight and develop H2S. The amount of H2S evolved seems to depend on the reaction temperature used, the amount of P4S7 contained as an impurity in the P4S3 used and the water content of the Depend reaction product. The presence of P4S7 can be determined by using a purified Phosphorus sesquisulfide should be avoided. The water content can be reduced to a minimum by working as free of water as possible during production. Treatment with Clay causes the extract from the clarified circulating oils to adsorb significant amounts of water.

In order to avoid the formation of HaS later, it can be useful to remove the water from the Remove extract before reacting with P4S3.

Although the good properties of the fuels improved according to the invention by the additives are not significantly affected by the discoloration or the elimination of H2S, can suppress these properties

be desirable from the standpoint of the saleability of the new fuels. It has been found that the use of only 0.5 percent by weight of zinc naphthenate (calculated on the weight of the PiSs reaction product) generally leads to adequate light and HfeS stability. However, concentrations up to 2.5 percent by weight may be useful. Generally more than 2.5 weight percent zinc naphthenate is uneconomical. The stabilization is carried out by heating the P4S3 reaction product to a temperature of about 32 to 95 ° C., adding the zinc naphthenate and then ^{maintaining the temperature mentioned for about 1} ^ to 4 hours.

To improve the light and HaS stability the soaps of aliphatic carboxylic acids with heavy metals can also be used. Suitable Heavy metals are: lead, manganese, cobalt, nickel, copper and cadmium. The used Carboxylic acids should contain chain lengths of at least 6 carbon atoms. Suitable acids are: hexane, Lauric, palmitic, oleic, stearic and linoleic acids.

It has been found that an irreversible precipitate is formed when is brought to a temperature below 50 ⁰ C, the P-ISS reaction product (before or after stabilization). Repeated cooling leads to the formation of additional precipitates whenever the temperature of the reaction product falls below 4 to 5 ° C. The precipitate does not redissolve when the temperature of the reaction product is increased above 4 to 5 ° C. The analysis shows that the precipitate does not consist of P4S3; on the other hand, the remaining liquid shows a decrease in the phosphorus content. If the amount of precipitate formed is relatively small, it can be filtered off and the remaining liquid used as an additive for the purposes of the invention. The formation of precipitates can be completely avoided if about 0.1 to 2 percent by weight sodium hydroxide is added to the P4S3 reaction product. Even if the reaction product treated in this way is repeatedly ^{cooled to 0} ° C., no precipitate is formed. The reaction product is ^{so highly viscous at temperatures below 0 °} C. that under these circumstances no precipitate is formed even without treatment with sodium hydroxide.

When the PaSs reaction product has been introduced into an engine _{fuel, the only problem left is the formation of H 2} S. For certain areas of use, the odor of the fuel is of no importance. Suppression of H2S formation is not necessary for such purposes. For areas in which the odor of the fuel has to be taken into account, the formation of HsS can be avoided by treating the concentrated additive with zinc naphthenate, as mentioned above, and then adding the modified additive obtained in this way to the gasoline according to known methods.

The problems of light and temperature stability lose their importance when the RiSa reaction product has been added to the engine fuel. The aforementioned auxiliary methods for improvement the light and temperature stability are only needed when the reaction product is concentrated Mold is stored or shipped in conditions where instability is possible.

The gasolines improved according to the invention with the P4S3 reaction products can all gasoline commonly used in the manufacture of fuels for spark-ignited internal combustion engines be used. These include catalytic distillates, motor polymers, alkylates, catalytic reformates, isomers and heavy petrol. The gasoline in question is included in the general anti-knock agents of the tetraalkyl lead type, such as tetraethyl lead, tetramethyl lead or chemical ones or physical mixtures of these compounds. You can also use a detergent such as ethylene dichloride and / or ethylene dibromide.

The amount of anti-knock agent is generally about 0.65 ecm per liter, but can 0.11 ecm per liter to 1.30 ecm per liter. The gasolines can also contain other common additives such as solvent oils and dyes.

The amount of the P4S3 conversion product contained in the fuels according to the invention can vary and is expediently expressed in the form of the theoretical units (T) of phosphorus. A theoretical unit of phosphorus is the amount of phosphorus that is theoretically required is to keep with the lead of the tetraalkyl lead anti-knock agent to react with the formation of lead orthophosphate. Viewed stoichiometrically corresponds to 1.0 T 2 atoms of phosphorus for every 3 moles of tetraalkyl lead, calculated on this basis Additives present in concentrations that range from theoretical phosphorus units 0.01 to 2.00 T. The preferred range is 0.05 to 1.00 T. Generally, concentrations are over 2.00 T uneconomical.

Attempts to lower the octane number
Carrying out the experiment

As already indicated, a favorable octane effect is a decisive and unforeseeable advantage of the additives according to the invention compared to unreacted P ₄ S _3. The standard ASTM test and the motor octane test method were used. A precise description of these methods can be found in the “ASTM Manual for Rating Motor Fuels by Motor and Research Methods, 1960”, published by ASTM, 1916, Race St., Philadelphia 3, Penna / USA.

The basic fuel used in the tests had the following composition and properties :

25.0% alkylate

13.3% catalytic distillate

60.0% reformate (210 ⁰ C final boiling point)

1.7% n-butane
Tetraethyl lead (cc / 1) 0.65
Octane number
F ₁ = 99.0
F ₂ = 91.9

distillation

15% 6O ⁰ C

64% 175 ⁰ C

95% 180 ° C

End boiling point '.' 217 ⁰ C

ίο

Using this base fuel, the following mixtures were made for each mixture with three phosphorus concentrations of 0.2, 0.4 and 0.8 T.

Mixture A

Base fuel plus non-stabilized, obtained by heating about 1 hour to about 50 ⁰ C the reaction product of P4S3 and a 10 to 35 ° / () aqueous fraction of an extract of a clarified circulating oil having a final boiling point of 418 ⁰ C.

Mixture B

Base fuel plus P4S3 reaction product of the mixture A, stabilized with 0.5 weight percent of zinc naphthenate by heating for 15 minutes at 50 ⁰ C.

Mixture C

Base fuel plus commercial P4S3 (containing about 6% P4S7).

Mixture D

Base fuel plus purified P4S3 (containing approximately 0.2% P ₄ S ₇ ).

Mixture E.

Base fuel plus separately imported amount of commercially available, unreacted P4S3 and a 10 to 35% fraction of a clarified circulating oil extract in amounts equivalent to those Amounts are equivalent to those in Mixtures A and B at the three phosphorus concentrations mentioned are present.

Results

From the data given below, the octane losses for those mixtures in which the phosphorus was present as converted P4S3 ranged from less than Vs to about ¹ k of those losses found for those mixtures in which the phosphorus was present as unconverted P4S3 was present. It can also be seen that the presence of zinc naphthenate in the amount required for stabilization had no visible effect on the lowering of the octane number. The small differences that resulted were within the experimental error limits. Furthermore, it is found that the addition of separate, unreacted amounts of P4S3 and extracts of the clarified circulating oil (Mixture E) did not give the improvement that was achieved if the corresponding reacted products were not used. The degree of purity of the P4S3 used has no significant effect on the reduction of the octane number, since the small differences here were also within the error limits.

The following results relate to octane losses.

Mixture A Tabel Mixture C Table III (b) Mixture B Mixture C Mixture D Mixture E. 0.3 5 III (a) 1.6 (Engine) 0.9 1.8 1.6 1.5 Theoretical a
are phosphorus 0.5 (Scientific research) 2.0 1.6 3.0 2.0 1.9 0.2 0.9 Mixture B 2.5 2.5 4.8 2.6 2.5 0.4 0.3 0.8 0.6 Mixture A 1.0 Mixture D Mixture E. 0.9 1.7 2.0 Theoretical a
are phosphorus 1.5 2.9 3.2 0.2 2.6 4.8 5.1 0.4 0.8

Experiments regarding surface ignition "
Carrying out the experiment

The equipment used consisted of a CFR-48 motor with removable valves in the head of the engine and a counter for surface ignition. The combustion chamber was provided with two openings. One was for a standard spark plug and the other was for a special one Spark plug that was used as an ion gap. A mechanical one driven by a camshaft A switch was built in by which the ion gap was switched off when normal Flame fronts formed. When the ignition is set to top dead center, the The normal pilot flame fronts the ion gap at 15 to 18 ° behind dead center. The ion gap was for 80 degrees of crankshaft rotation between 70 ° before dead center and 10 ° after Dead center set. Flame fronts that are generated early in the cycle reach the ion gap during this operating period. Such early flame fronts are called surface ignitions registered.

809 517/582

The operating conditions of the machine included:

Compression ratio 10.5: 1

Ignition setting top dead center

Coolant temperature 52 ⁰ C

Air inlet temperature 67 ° C

oil temperature 89 ° C

For each fuel tested, the engine was run periodically over a period of 72 hours driven according to the following scheme:

Table IV

50 seconds, 600 rpm
150 seconds, 900 rpm

without load with wide open throttle mixture F ..,
Mixture G ..

Mixture H.

Phosphorus in T

Surface ignitions (number per hour)

0.1 T as P ₄ S ₃ .
Implementation product
0.1 T as P ₄ S ₃

217 92

101

The basic gasoline that was used for the tests had the following composition and Characteristics:

The results show that the lead-containing propellants according to the invention containing the P4S3 reaction products _{more than maintain the beneficial effects which unreacted P 4} S ₃ exerts on surface ignition.

60% catalytic reformate

25% alkylate

15% light catalytic distillate

Specific gravity 0.7559

Reid vapor pressure, at 0.557

ASTM distillation

Initial boiling point 57 ° C

5% 71 ° C

10% 79 ° C

30% 112 ° C

50% 131 ° C

70% 152 ° C

.90% 19O ⁰ C

95% 217 ° C

Final boiling point 240 ⁰ C

Octane number

Research method 101.0

Motors method 93.2

, The three fuel mixtures that were examined had the following compositions:

Mixture F

Base gasoline plus 0.65 ccm / 1 of a mixture of tetraethyl lead plus 0.5 T bromine in the form of Ethylene dibromide and 1.0 T chlorine in the form of ethylene dichloride.

Mixture G

Mixture F plus 0.1 T phosphorus in the form of the zinc naphthenate stabilized P4S ₃ conversion product of mixture B described above.

Mixture H

Mixture F plus 0.1 T phosphorus in the form of P ₄ S ₃ (produced by adding an intimate mixture of 0.1 T phosphorus as P4S3 and 300 ml of the mixture of tetraethyl lead, ethylene dibromide and ethylene dichloride of the mixture F to 4601 basic fuel).

Results

In Table IV the average number of surface ignitions found per Hour of operating time given for each fuel mixture tested. This is a quantitative one Determination of surface inflammation.

20 Investigation of the contamination of the spark plugs Carrying out the test

A Chevrolet engine (built in 1954) with six cylinders was used. The engine was with equipped with three carburettors connected to the engine by three separate intake manifolds was. This arrangement made it possible to compare three fuel products at the same time, thereby errors caused by a change in operating conditions from test to test can be turned off. The test fuels were exchanged in successive engine runs, so that individual cylinder effects could be determined. A pressure sensitive one Transducer connected directly to the engine's exhaust pipe indicated pressure pulses.

These pressure pulses correspond to and follow the ignition periods in the combustion chambers of the motor. During normal operation of the spark plugs, there is an increase in pressure in the combustion chamber and a corresponding pressure pulse in the exhaust pipe for every two revolutions of the engine for each cylinder. if if the spark plugs are contaminated, there is no pressure increase as a result of fuel combustion, and a pressure pulse in the exhaust pipe cannot be observed.

The number of engine hours it took to cause misfire is a quantitative one Expression for the effectiveness of a gasoline in the sense of preventing the pollution of the Spark plugs.

The operating conditions in detail were as follows:

Engine: Chevrolet (year of construction 1954) with six cylinders (3850 ecm)

1. Compression ratio 7.7: 1

2. Ignition timing 5 ° BTC

3. Air-fuel ratio 13.3: 1

4. Coolant temperature 92 ° C

5. Air mix temperature 67 ° C

6. Oil temperature 8O ⁰ C

Trial cycle

5 min. 50 sec. 2100 rpm 10.14 hp

10 sec. 2000 rpm wide open throttle

65 The test cycle is continuous for 140 hours or until all cylinders misfire repeated.

13th

Fuels

The base gasoline used in this experiment had the following composition and features:

65% catalytic reformate 35% alkylate

Specific gravity 0.7870

Reid vapor pressure, at 0.482

ASTM distillation

Initial boiling point 5% 10% 30% 50% 70% 90% 95% Final boiling point of spark plugs, which is determined by the fuels according to the Invention is given.

Mixture I.
Mixture K

Phosphorus content

(theoretical

Units)

0 0.2 T

Hours to
Spark plug malfunction

15th
140

20th

Octane number

Research method 101.9

Motors method 92.3

The two fuel mixtures examined had the following composition:

Basic petrol liters

Mixture I plus 0.44 ecm of tetraethyl lead per

Mixture K

Consists of the basic petrol plus 0.44 ecm of tetraethyl lead per liter and 0.2 theoretical units Phosphorus in the form of the fuel additive in mixture A.

Results

The following experimental data demonstrate the superior protection against pollution of the The test was ended after the engine had run for 140 hours without the spark plugs being dirty was running.

Claims (3)

Patent claims: 1. Lead-containing fuels for gasoline engines, characterized in that they 0.01 to 2.00 theoretical units of phosphorus in the form of one from P4S3 and from an extract reaction product obtained from a clarified circulating oil, which may also contain a a small amount of zinc naphthenate and / or alkali hydroxide has been added. 2. Fuels according to claim 1, characterized in that they contain the phosphorus in the form of a reaction product from P4S3 and from an ^{extract boiling in the range of about 205 to 538 0} C and containing at least 50% of the carbon atoms in the form of aromatic compounds contain clarified circulating oil. 3. fuels to claim 1 or 2, characterized in that they contain the phosphorus in the form of a reaction product from P4S3 and an extract, the output of which product had a boiling range of about 288 to 400 ⁰ C according to. Considered publications:
U.S. Patent No. 2,935,390. 809 517/582 2.68 ® Bundesdruckerei Berlin