US2071064A - Stabilization of motor fuels - Google Patents

Description

resinous products. The most common type of compounds, which have been employed for this.

Patented Feb 116,1937

- UNITED STATES PATENT bas cs v s'ranmza'non or Moron Frederick Baxter and Richard Geese Carneys Point, N. I Glarkson and aasignors, by memo assignments, to Gasoline Antioxidant Company, Wilmington, Del, 1 I corporationoflielaware I No Drawing. Application September at, 1933,

- ScrialNo. 690,418

. 1'; claims.

This invention i elates to the stabilization of motor fuels comprising cracked hydrocarbon spirits such as cracked gasoline and motor benzol. It is well known that motor fuels. comprising cracked. hydrocarbon spirits normally tend. to

form-gummy and resinous products upon storage, which products are highly objectionable. Cracked gasoline particularly is subject to this form'of deterioration. Also, motor fuels such as motor benzol are produced containing cracked hydrocarbon spirits which also tend to form" gummy and resinous products. Motor fuels comprising cracked hydrocarbon spirits have been treated by various means to remove the cracked spirits. This has been found to be objectionable for motor fuels to be used inpresent day automotive internal combustion-engines. Accordingly, it'has been suggested to add to such motor fuels various compounds which will inhibit or retard the formation of gummy and purpose, are the phenolic and amino compounds. The phenolic type of compounds have generally been preferred because the'amino type usually discolor the motor fuelor accelerate discoloration thereof. The phenolic type of compound, how- 'ever, is generally objectionable due to its low solubility and its corrosive characteristics. It has been proposed to employ amino hydroxy 1 compounds to obtain the advantages of both the phenolic and amino compounds without their disadvantages. This. last expedient has not proved to be entirely satisfactory as the amino phenols, such as para-amino-phenol, are insufllciently soluble in the gasoline and also tend to discolor upon storage. It has been proposed to employ substituted amino-phenols,in order. to

overcome the disadvantages of compounds such ,as para-amind-phenol. This last expedient has met with some degree of success. latter compounds, as a general rule, tend to discolor the motor fuel on storage to some extent over extended periods of time.

An object of the present invention isto provide new compounds to be employed for stabilizing motor fuels comprising cracked hydrocarbon spirits'which compounds are exceedingly effective for preventing the formation of gum in the motor fuels and do not'discolor the motor fuels during storage; A further object is to'provide.

improved methods for stabilizing motor fuels comprising cracked hydrocarbon spirits. Another object is to provide motor fuels comprising cracked hydrocarbon spirits which do not discolor and in which the tendency to form gum is greatly inhibited. Still other objects are to provide new compositions of matter and'to ad- ,vance the'art. Other objects will appear herein- However. these (oi. u- -si' These obiects may accomplished in accordance with our invention which comprises incorporating' in motor fuels comprising cracked hydrocarbon spirits, suchas cracked gasoline and.

motor benzol, a compound of the type:

-'- (Hie-OH:

aliphatic hydrocarbon group in which at least one 2 hydrogen is substituted by an aryl nucleus.

Among the compounds which we have found to be particularly satisfactory for our purpose are p-hydroxy N-phenyl morpholine, 4-hydroxy-2- methyi-N-phenyl morpholine and 4-hydroxy-3-' methyl-N-phenyl morpholine. Methods of making compounds of this type are disclosed in the patent to'I-Iorace B. Pray, No. 2,063,191. Briefly, the hydroxy aryl morpholines are prepared by heating an aminophenol with beta beta dichlor ethyl ether in the presence of water and a mild inorganic alkali such as magnesium hydroxide,

magnesiumoxide, calcium carbonate,'zinc oxide and the like under'slight superatmospheric pressure. The hydroxy aryl morpholine I obtained will be the one corresponding with the aminophenol employed. These compounds are insoluble in water and will precipitate from the,

solution and can be easily separated therefrom.

. The eifectiveness of these compounds asantigumming agents was tested essentially according a to the method proposed by Voorhees and Essinger in J. S. A. E. 24, 584 (1929). In this test, cc.

of the motor fuel is heatedin a glass flask under an oxygen atmosphere at 100 C. The flask is connected to a mercury manometer and-the pres sure observed at regular intervals. The elapsed time, from the start of the test until the motor fuel begins to absorb oxygen, as shown by the fall of the pressure, is known as the "induction peri- 0d of the fuel. The effectiveness of an anti-- gumming' agent or gum inhibitor is measured by the increase'in the induction period caused.

by the addition of a known amount of inhibitor.

.That the inductionperiod is directly related to gum formation can be shown by heating a control sample of gasoline, containing no inhibitor,

beyond its induction-period and a second sample a v of gasoline, containing the inhibitor, for the same'length of time and determining the gum formed in each case by evaporating the gasoline samples in tared dishes in an inert atmosphere. The residue is the gum formed in each case.

As is well known to those skilled in the art, p-aminophenol, under the above test conditions, gives very satisfactory results. The use of this compound is not, however, commercially practiv 0.003% by weight cal since its solubility, at ordinary temperatures, is insufficient to permit the use of a suiiicient amount of the compound. Moreover, gasoline, containing p-aminophenol, is rapidly discolored under the action of light and air.

Wehave now found that the hydroxy N-aryl morpholines and particularly the p-hydroxy N-phenyl morpholines and the o-hydroxy N-phenyl morpholines are free from these disadvantages, Their solubility in gasoline is suflicient to permit the use of the quantity required to give an effective stabilization of the gasoline and their solutions in gasoline do not become colored during storage over extended periods of time.

In order to more clearly illustrate our invention and the advantageous results to beobtained thereby, the following examples are given:

Example 1 A gum-free unsaturated gasoline, containing 0.002% by weight of p-hydroxy N phenyl morpholine, had an induction period of 270minutes, when subjected to the above described test. A control sample of the same gasoline, containing no inhibitor, had an induction period of only 60 minutes, under the same conditions.

Erample 2 A gum-free unsaturated" gasoline, containing pholine, had an induction period of 460 minutes,

as determined by the above test. The control sample, without riod,of only .60 minutes.

During this last test, samples 'of gasoline were withdrawn at the end of 240 minutes and evap- 'orated in a .steam oven in tared dishes. The weight of gum, obtained from the uninhibited sample, was 246 mg. from 25 cc. of gasoline. The weight of gum, obtained from the inhibited sampie, was 3 mg. from 25 cc. of gasoline.

, Example 4 Example 3 A gum-free unsaturated gasoline, containing 0.003% by weight of 4-hydrom-2-methyl-N-phenyl morpholine, had an induction period of 130 minutes. The control sample gave 70 minutes, under the'same conditions.

-A gum-free unsaturated gasoline, containing 0.003% by weight or 4-hydroxy-3=methyl-N-phemorpholines should also be mentioned. Other compounds within the class which may be mentioned are: 4-methy1-2-hydroxy-N-phenyl morpholine, 3-butyl-2-hydroxy-N-phenyl morphoof p-hydroxy N-phenyl morinhibitor, had an induction pe'- line, 4-hydroxy-N-phenyl-3-5-dimethyl morpholine. I

The aryl group may also contain 2 or 3 hydrocarbon substituents which may be alike or diflerent;

The amounts of the gum inhibitors, which it is necessary to employ, will vary with the nature and concentration of the unsaturated constituents of the motor fuel and the degree of stabilization it is desired to obtain. In general, however, the concentration of inhibitor in the motor fuel will be substantially less than 0.1 by weight.

From all of the above, it will be apparent that we have discovered a new class of compounds which are very emcient gum inhibitors, which are sufflciently soluble in gasoline to be readily utilized, and which do not cause noticeable discoloration of the motor fuel in aging.

While we have disclosed certain specific embodiments of our invention and the preferred modes of carrying the same into effect, it will be readily apparent to those skilled in the art that many variations and modifications may .be made therein without departing from the spirit of our invention. Accordingly, the scope of our invention is to be limited solely by the appended claims construed as' broadly as of the prior art.

We claim:

1. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances on storage having incorporated therein, in an amount suilicient to inhibit the formation of the gummy substances, 9. compound of the GHQ-CH1 wherein It represents an aryl nucleus.

is permissible in view 3 2. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy sub-' stances on storage having incorporated therein,

in an amount suflicient to inhibit the formation of the gummy substances, 8. compound of'the type:

Clif -CHI HO-R-N y I I CHrG z wherein R represents a phenyl nucleus.

3. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances on storage having incorporated therein, in an amount suflicient to inhibit the formation r of thegummy substances, a compound of the CHr-CH! wherein R represents an aryl nucleus having substituted therein at least one member of the group consisting of alkyl, alkaryl and aryl groups.

- Ho-n-N o era-cm wherein' R. represents a phenyl nucleus having substituted therein at least one member of the group consisting of alkyl, alkaryl and aryl groups.

5. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances on storage having incorporated therein, in an amount sufficient to inhibit. the formation of the gummy substances, a compound of the type: I

/CHl'CHs HO-RN\ car-cm wherein R represents an aryl nucleus and wherein the hydroxy group is para to the morpholine radical.

6. Motor fuel comprising cracked'hydrocarbon spirits normally tending to form gummy substances on storage having incorporated therein, in an amount sufllcient to inhibit the formation of the gummy substances, a compound of the type:

CHr-CH,

wherein R represents a phenyl nucleus and wherein the hydroxy group is para to the morpholine radical.

7. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances on storage having incorporated therein, in an amount sufllcientto inhibit the formation of the gummy substances, a compound of the typ CHr-CKK carom wherein R represents a phenyl nucleus having substituted-therein at least one member of the group consisting of alkyl, alkaryl and aryl groups and wherein-the hydroxy group is para to the morpholine radical. g

8. Cracked gasoline normally tending to'form gummy substances ,on storage having incorporated therein, in an amount sumcient to inhibit the formation of the gummysubstances, a compound of the type:

CHI-CHI no-no CHrCHI wherein R represents an aryl nucleus.

9. Cracked gasoline normally tending to form gummy substances on storage having incorporated therein, in an amount sui'iicient to inhibit the formation of the gummy substan a compound of the type:

CHI-C no-no I CHr-CHs I wherein -R represents a phenyl nucleus.

10. Cracked gasoline norm lly-tendin to form" gummy substances on storage having incorporated therein. in an amount suiiicient to inhibit the formation of the gum substance a compound of the typ i V OKs-CH4 v no-n--n o wherein R represents an: aryl nucleus ha lisdroxy sufilcient to retard the formation of said gummy substances.

substituted therein at least one member of the groupconsisting of alkyl, alkaryl and aryl groups.

11. Cracked gasoline normally tending to form gummy substances on storage having incorporated therein, in an amount suiilclent to inhibit the formation of thegummy substances, a compound of the type: i I

. OHr-OHs HOB-N\ o OKs-CH:

wherein R represents a phenyl nucleus having substituted therein at least one member of the group consisting of alkyl, alkaryl and aryl groups.

12. Motor benzol normally tending to form gummy substances on storage having incorporated therein, in an amount sufllcient to inhibit the formation of the substances, a compound of the type:

ca -oa wherein R represents an aryl nucleus.

13. Motor benzol normally tending to form gummy substances -on storage'having incorporated therein, in an amount suflicient to inhibit the formation of the gummy substances, a compound of the type:

BIO-11- OKs-Cling OKs-CH1 R represents a phenyl nucleus.

benzol normally tending'toform storage having incorposufllcient to inhibit wherein 14. Motor gummy substances on rated therein, in an amount the formation of the gummy substances, a compound of the type:

on on, no-n-rr 0 CHr-CH! v u wherein R represents an aryl nucleus having substituted therein at least one member of the group consisting of alkyl, alkaryl and aryl groups.

- 15. Motor benzol normally tending to form gummy substanceson storage having incorporated therein, in an amount sufficient to inhibit the formation of pound of the type: v a

I CHs-CH!\ OBPCHQ/ N-phenyl morpholine mans-men nsx'rm nowsma. mcnsnn oases cnsnxson'.

the gummy substances, a com-