US2955928A - Gasoline composition - Google Patents

Description

GASOLINE COL [POSITION Warren Maxwell Smith, Baton Rouge, La., and Richard F. Nehlett, Elizabeth, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Sept. 11, 1956, Ser. No. 609,062

Claims. (Cl. 44-56) The present relates to improved motor fuels and methods for making them, particularly to motor fuels containing additive agents adapted to reduce or prevent gum problems in the motor while simultaneously lubricating the moving parts in the upper part of the motor. More particularly, the present invention relates to a gasoline composition containing an improved solvent oil adapted to prevent valve stem and piston ring sticking and serve as a general purpose upper cylinder lubricant.

The use of solvent oils in gasoline compositions to prevent ring and valve sticking and provide upper cylinder lubrication has long been known. Conventional solvent oils are described in US. Patent 2,066,234, issued to Sloane and Wasson on December 29, 1936. This patent defines a solvent oil as consisting of a liquid hydrocarbon mixture having a 50% distillation point above 350 F. at mm. Hg pressure, having a Saybolt viscosity at 100 F. not above 450 seconds, and having an A.P.I. gravity of about 18-28". A typical solvent oil, for example, has the following inspection:

50% distillation point 10 mm. H 413 Saybolt viscosity 100 F 75.3 A.P.I. gravity 26.6

In general, the solvent oil concentration in a gasoline may range from about 0.05 to 1.0%.

The solvent oils generally employed are hydrocarbonaceous, and have selective solvent action for hydrocarbon gums, sludges and varnishes. However, oxygenated gums and resin are not readily removed by these solvent oils, and it would be highly desirable to employ as a solvent oil, or as an adjuvant to solvent oils, a composition that has high specificity for gums and varnishes. in the past, various oxygenated solvents havebeen added to gasoline for this purpose, but these materials have not been wholly effective, either because of'to'o high vapor pressure at motor operating conditions, or because excessive quantities were required. Thus, it has been suggested that high boiling esters such as amyl stearate be employed as a solvent oil. Such esters, however, have not given satisfaction and their solvent powers are inadequate.

The need for a highly active solvent oil type additive has been long recognized. A tendency to cause manifold deposit and intake port deposit buildup represents a serious fuel deficiency, particularly when the fuel is used in low temperature service with considerable engine idling time. Catalytically cracked gasolines which have comparatively high octane numbers and are thus widely used are unstable and require the use of an antioxidant. Both these unstable fuels and antioxidant residues contribute to manifold deposits. Use of a solvent oil type additive represents a desirable method of minimizing these deposits.

It has now been found that excellent solvent oils may be prepared by fortifying conventional hydrocarbon type solvent oils with particular liquid synthesis products deand hydrogen in the presence of a cobalt carbonylation rived from the reaction between olefins, carbon monoxide 2,955,928 Patented Oct; 11, 1960 reaction catalyst; The carbonylation, or 0x0 reaction as it is commonly called, is Well known in the art as a method of preparing alcohols from olefins, the former having one more carbon atom than the olefin from which it is derived. It is a two-stage synthesis wherein, in the first stage, olefins, CO, and H are reacted in the presence of a cobalt catalyst at pressures of about 2000-4000 p.s.i.g. and temperatures of 275 to 375 F. to form an aldehyde product containing one more carbon atom than the parent olefin, and, in the second stage, the aldehyde product is subsequently hydrogenated to form the corresponding alcohol. The process is described in U.S. Patent 2,327,066 to Roelen; in 2,504,682 to Harlan and in many subsequent patents. distillation of the alcohol fraction, commonly referred to as Oxo bottoms that are the solvent oil fortifying components of the present invention. In the carbonylation of a heptene fraction obtained from propylene-butylene copolymerization, for example, the bottoms represent about 1530% of the crude alcohol charged to the distillation zone. The bottoms consist primarily of highly branch chained C alcohols, C acetals, C ethers, both saturated and unsaturated, and minor amounts of other oxygenated compounds, such as aldols, esters and the like. A typical analysis of the composition obtained from carbonylation of a heptene polymer fraction is as follows:

Percent (Weight) Though for any particular olefin fraction being carbonylatedthe magnitude of these constituents may vary, the relative proportions generally remain fairly constant. Thus, a propylene fraction, a heptene fraction, a C and a C fraction may be carbonylated and the bottoms employed. The constituents of OX0 bottoms are all characterized by being highly branch chained, even though relatively straight chain olefins are originally carbonylated. This arises out of the isomerizing characteristics of the cobalt carbonyl catalyst and the fact that the addition of the group may be to either one of the double bonds. A sample of a C Oxo bottoms has the following Engler distillation at 10 mm.

Percent distilled: Temp, F. I.B.P. 184 5 220 10 220 435 486 F.B.P. (98%) 503 It is the still pot residues after the ,It has further been found that the inclusion of x0 bottomsin the solvent oil has a marked effect upon the sludge resistance characteristics of mineral oil type solvent oils..

It has beenfound that 'a solvent oil which'resists sludge gasoline its'elfor isinjected into the manifold in any desired manner in order to contact the gum-coated surface.

The amount ofqsolvent' oil to be used may vary over a WideIa gQdepending'u On various'factors. such as the type of motor fuel being used and the type of engine. In general, from 0.05 to 1.0% of solvent oil is sutlicient, and preferably the amount used is between 0.10 and 0.75% by volume, based on the gasoline blend. The solvent oil itself, in accordance with the present invention, contains from 1 to 50%, and preferably 5 to 30% of OX9 bottoms.

The; solvent oil composition of the present invention is also useful for dissolving and fluxing gummy deposits from fuel systems of diesel engines, oil burner installations, jet engines, turbines and the like. Furthermore, it may be combined with additives .inmotor fuels having other properties, such as dimethyl carbinol for de-icing, various anti-rustagents and the like.

7 EXAMPLE I 7 "IfheSligh testis an accelerated oxidation test which measures the resistance of an oil to oxidation and the formation of sludge. A sampleof the, oil is placed in a specially constructed vessel which is charged with oxygen. The vesselis then heated in a bath for a specified time and .at a specified temperature. .At' the endithe oil isdiluted with a light naphtha, filtered, andthe weight of precipitate reported as the Sligh number.

Mineral solvent oil A was an acid treated coastal distillate .of 86.5 SUS/IOOKFL f Mineral solvent oil B was an untreated distillate of 79 SUS/ 100 F. from Venezuelan crude.

The effect upon the Sligh number of admixing Oxo bottoms with distillate mineral solvent oils is shown in the following example. For comparison, the effect of the addition of a high boiling material such as amyl stearate is shown.

Sligh number (mg.

hydrocarbon solvent oil is"blended'vvith'Oxo' bottoms in eo ncentrations -afslo'w asl0%',the'Sligh N'oQof the blend less'than 50% of the original value for the solvent oil; 011" the othefhaiid, atthese" low concentrations,

amyl stearate gives no significant lowering ofthe Sligh number of the hydrocarbon solvent oil."

Yfj EXAMPLE n- -E'I'hefollowingtestsshow that the-Sligh number is a significant measure ofthe abilityof- -a-sol-vent oil to lower It canrbe seen that to be most effective The relationship of Sligh number of the solvent oil 7 and theability of the oil to reduce intake manifold deposits was studied in a series of thirty-eight single cylinder engine tests. The test method employed correlates with field performance. Regression analysis by methods outlined in Brownleeis iIndustIialExperimentation, Chemical Publishing Co. (1949), showed'that increasing Sligh'number increased the amount of manifold deposits.

Additional tests were run 'in a Lauson engine, first using a gasoline containing'a mineral solvent oil and Oxobottomsand then. using a sample. of the same gasoline containing amyl stearate in place of the Oxo bottoms. After each test, the manifold waswashed first with heptane and then with acetone. The solvents were evaporated from the washings and the weight of deposit determined.' The hePtane-insoluble,acetone-soluble deposit is the significant one. 7 v a a The One bottoms product was that described earlier, obtained from propene-butene copolymer.

Lauson engine manifold tests {0.5 vol. percent solvent oil in gasoline] Acetone- Soluble Test SolventQll Sligh No. of Ma-nifold Solvent Oil Deposits. mgJlb. of gasoline Solvent Oil A75 vol. percent..-" {0x0 Bottoms25 vol. percent 8 {Solvent Oil A-75 vol. per0ent 4 72 6 Amyl Stearate25 vol. percent From these data it is apparent that the oils with the low Sligh numbers have significantly lower engine deposits than those with high Sligh numbers. :It -is also apparent that Oxo bottoms are niarkedlysuperior to esters such as amyl stearate. q n

' EXAMPLE HI 7 The unexpected o igidation stability imparted to conventional. hydrocarbon solvent oils by OXO bottoms is particularly observable when larger proportions of the latter are employed. This is seen in the following tabulation:

Ce. 7 Sligh N0.

(1) 0x0 bottoms. 150 1 1.0 (2) Solvent Oil A 150 47. 3 (3) Mixture of (1) and (2) 1.6

7 Predicted Sligh No. for (3), average of V p values for (1) and (2) 24. 2 (4g Solvent Oil A- 42.1 (5 0x0 bottoms" 1.0 (6) Solvent Oil B 60.0 (7) Mixture of (4), (5) d (6) r 15.5

Predicted Sligh No. for (7), average of values for (4), (5) and (6). 34. 4

' The solvent power ofmineral solvent-oils is markedly improved by the presence of OX0 bottoms. 'This is further shown by :thedecreasein aniline. point when increasing amounts of this additive are incorporated in mineral solvent oils. a l 5 Insolvent oil B In solvent oil A Percent Oxo bottoms: Aniline point F.)

In general, Oxo bottoms may be incorporated with any type of commercial solvent oil adapted to be used with fuels such as gasolines, diesel fuels and the like. Because of the high potency and anti-oxidation characteristics of solvent oils containing Oxo bottoms, mineral oils which otherwise would not be suitable for this service may be employed as solvent oils in accordance with the invention. In general, mineral solvent oils have viscosities at 100 F. (SUS) of about 70 to 90, aniline points of 160 to 170 F., and A.P.I. gravities of 25 to 28.

What is claimed is:

1. A motor fuel comprising a major proportion of light petroleum hydrocarbons and 0.05 to 1.0% of a solvent oil as a lubricant and deposit remover, said solvent oil containing 50 to 99% of petroleum hydrocarbons and 1 to 50% of the mixture of oxygenated organic compounds produced as still bottoms product of the x0 reaction, wherein H CO, and an olefin having from 2 to 15 carbon atoms are contacted at elevated temperatures and pressures in the presence of a carbonylation catalyst to produce an aldehyde product which is subsequently hydrogenated to the alcohol product, and thereafter removing the major portion of the C to C alcohol component by distillation, leaving behind said still bottoms product.

2. The composition of claim 1 wherein said hydrocarbon iuel is an internal combustion engine fuel, the mineral oil constituents of said solvent oil have an SUS viscosity in the range of about to at F., and said still bottoms are derived from the oxonation of a butene-propylene copolymer.

3. The composition of claim 1, wherein said solvent oil contains about 5 to about 30% of said distillation bottoms.

4. The composition of claim 1 containing a small amount of dimethyl carbinol.

5. The composition of claim 1, wherein said olefins have from 6 to 15 carbon atoms per molecule.

References Cited in the file of this patent UNITED STATES PATENTS 1,582,420 Nikaido Apr. 27, 1926 1,692,784 Orelup et a1 Nov. 20, 1928 2,066,234 Sloane et al. Dec. 29, 1936 2,236,590 Backoff et al Apr. 1, 1941 2,350,145 Backofi et al. May 30, 1944 2,789,891 Brandes et al. Apr. 23, 1957 2,843,463 Gaston et al. July 15, 1958

Claims (2)

1. A MOTOR FUEL COMPRISING A MAJOR PROPORTION OF LIGHT PETROLEUM HYDROCARBONS AND 0.05 TO 1.0% OF A SOLVENT OIL AS A LUBRICANT AND DEPOSIT REMOVER, SAID SOLVENT OIL CONTAINING 50 TO 99% OF PETROLEUM HYDROCARBONS AND 1 TO 50% OF THE MIXTURE OF OXYGENATED ORGANIC COMPOUNDS PRODUCED AS STILL BOTTOMS PRODUCT OF THE OXO REACTION, WHEREIN H2, CO, AND AN OLEFIN HAVING FROM 2 TO 15 CARBON ATOMS ARE CONTACTED AT ELEVATED TEMPERATURES AND PRESSURES IN THE PRESENCE OF A CARBONYLATION CATALYST TO PRODUCE AN ALDEHYDE PRODUCT WHICH IS SUBSEQUENTLY HYDROGENATED TO THE ALCOHOL PRODUCT, AND THEREAFTER REMOVING THE MAJOR PORTION OF THE C3 TO C16 ALCOHOL COMPONENT BY DISTILLATION, LEAVING BEHIND SAID STILL BOTTOMS PRODUCT.

4. THE COMPOSITION OF CLAIM 1 CONTAINING A SMALL AMOUNT OF DIMETHYL CARBINOL.