US1930248A - Process for treating gasoline or the like - Google Patents

Description

Patented Oct. 10, 1933 UNITED STATES PATENT OFFICE PROCESS FOR TREATING GASOLINE OR THE LIKE No Drawing. Application November 11, 1929 Serial No. 406,518

3 Claims.

This invention relates to stabilization of gasolines, and more particularly to the prevention of color formation and gum forming substances in gasoline, and also to prevent the reduction in 5 antiknock properties of said gasolines on storage.

It has been observed that when gasolines are stored, particularly cracked gasolines, and especially under the influence of light and oxygen,

1 chemical changes occur which affect the color,

increase the gum formation, and reduce the antiknock properties. In some cases all of these changes occur simultaneously, while in others they occur independently or in pairs. Although the chemistry of these changes is not thoroughly understood, I have discovered that certain compounds act as stabilizing or inhibiting agents and substantially prevent this undesirable chemical change from occurring.

Generally speaking, cracked gasolines are composed of mixtures of hydrocarbons, principal among which are the aromatic, unsaturated, naphthene, and parafiin hydrocarbons. While it has not been definitely proven, it is believed that color and gum formation and reduction in antiknock properties upon storage involve changes in the unsaturated compounds, more particularly in the highly unsaturated compounds such as diolefins, terpenes, and related compounds.

Oxidation products of the various hydrocarbons present in the gasolines are apparently responsible also for the changes noted.

The formation of color in gasolines is undesirable mainly from a marketing viewpoint, for changes in color are usually accompanied by the formation of gum-like and polymer-like materials which aifect not only the sale of the gasoline when dispensed from visible bowls, but also the operation of the motor owing to clogging of the gasoline feed lines, interference with the proper operation of the carburetor, and the sticking of valves in the motor. Gum formation is likewise objectionable for the same reasons.

The gum content of a gasoline is measured by a test which involves the gum formation. The present test is stated in terms of milligrams of gum formed upon the evaporation of a specific volume of the gasoline, namely 100 cc. The presence of oxygen during evaporation increases the gum formation, but as this condition is one which is present in the use of the gasoline, it has a bearing upon its performance in the motor. The so-called gum content of the gasoline will also vary as a function of the material in which it is evaporated, for example, in the presence of copper, the resulting gum will be very much higher than in glass. These tests have a bearing upon the performance of the gasoline in the motor and its auxiliary feed system, and the beneficial effects of my invention will be indicatfed by such tests as well as by actual motor tes s.

The antiknock property of a gasoline is among its most important and valuable characteristics. The higher the antiknock value or rating of a gasoline, the more efficient it is as a motor fuel. Knocking in a motor is an index of inefiioient operation because energy which otherwise would be utilized in the operation of the motor must be dissipated by rapid cooling, and unless this remedy is resorted to, a condition will be set up where auto-ignition occurs, thus interfering with the normal functioning of the motor. It has been observed that the higher the compression pressure or compression ratio of a motor, the greater the tendency for a given fuel to knock, and inasmuch as the efficiency of a motor increases with compression pressure and compression ratio, it is desirable that a motor fuel possess sufliciently high antiknock properties to avoid knocking. The present tendency is to increase the compression pressure of motors in order to increase their efiiciency or mileage per gallon of fuel consumed so that antiknock fuels are at a premium.

The change in antiknock rating during storage of a motor fuel is particularlyembarrassing inthat although the antiknock rating of a tank of motor fuel is established and found to be satisfactory, there is a complete uncertainty 'as to its antiknock value at the time of sale. The economic loss of restoring such gasolines to their original antiknock value can be realized from cases which have been observed where the antiknock value has dropped from approximately fifty percent benzol equivalent to zero percent over a period of several months standing.

I have discovered that when relatively small amounts, forexample, from a trace up to two percent, more or less, of the inhibiting or stabilizing agents which are the subject of this invention are added to a gasoline which shows a tendcncy to depreciate with respect to color, gum, and antiknock properties, that such gasolines will pratically retain their original condition. I have found that these inhibitors or stabilizers are effective in preventing or reversing the changes which take place as a result of storage, exposure to light, or oxidation naturally occurring or under accelerated conditions.

I have discovered that camphor and its related derivatives, such as camphorphorone and camphoric acid and others when added to motor fuels, especially cracked gasoline, are capable of accomplishing the stabilizing and inhibiting effects above pointed out, more particularly with respect to the stabilization of color and antiknock values, and in the present invention I employ for the purposes set forth the compounds named.

Certain of the above compounds may possess antiknock properties, but the present invention is to be distinguished from the mere addition of antiknock compounds to motor fuels in that my treatment prevents deterioration of the gasoline upon storage or removes undesirable characteristics which have formed during storage, particularly with respect to color and antiknock depreciation. In my invention the amount of reagent employed is materially less than that required in motor fuels to impart antiknock properties thereto.

As examples of the color stabilizing properties of camphor and its related derivatives, I may cite the following:

Starting with a gasoline of 18 color, which on exposure to diffused sunlight for several days dropped to 14, I have found that by the addition of approximately 0.1% of camphor and some of its derivatives that the resultant color under similar conditions of exposure is 19; actually showing an improvement in color with the stabilizer.

Similarly I have found that with certain gasolines showing a marked tendency to depreciate in antiknock value without the addition of camphor and its derivatives one can by the addition of approximately 0.1% of camphor avoid such depreciation. As an example a cracked gasoline upon storage without the use of my reagents dropped in antiknock valueto zero benzol equivalent from a value of approximately 35% benzol equivalent when stored for several months. Upon the addition of 0.1% camphor this depreciation in benzol equivalent or antiknock rating was prevented under similar conditions of storage. I have found further that under accelerated conditions of depreciation in antiknock value, for example exposure of a cracked gasoline to the action of oxygen at elevated temperatures, which ordinarily caused a very marked depreciation in antiknock-value, that such depreciation would be prevented by the addition of small amounts of camphor.

Stabilization of gum formation was also observed, for example with a gasoline showing a gum content of 15 milligrams by the copper dish test. No substantial increase in the gum formation was observed, after a long period of storage or exposure of the gasoline to which a small quantity of camphor or its derivatives was added.

It can be appreciated that the present inven tion is of prime importance to the oil refining industry since it assures a stable product after refining, and at the same time avoids a large expenditure in bringing out the anti-knock properties of depreciated gasoline by the addition of costly antiknock dopes or hydrocarbons, for example benzol. These inhibitors are not to be confused with antiknock dopes because the amount added will impart practically no antiknock properties per se, but simply acts to prevent the loss of antiknock and other desirable properties of the gasoline.

The above examples are given by way of illustration only, and are not to be construed as limitations upon the spirit and broad scope of the invention.

I claim:

1. The process of reducing deterioration during storage of cracked gasoline having anti-knock properties which comprises adding to such gasoline a compound selected from the group which consists of camphor, camphorphorone, and camphorio acid.

2. The process of reducing deterioration during storage of cracked gasoline having anti-knock properties which comprises adding camphor to the cracked gasoline.

3. The process of reducing deterioration during storage of cracked gasoline having anti-knock properties which comprises adding approximately 0.1% of camphor to the cracked gasoline.

JACQUE C. MORRELL.