US1365052A - cohew - Google Patents

Description

UNITED STATES PATENT OFFICE.

CABLE-TON EILES, O1 MONTCLAIR, NEW JERSEY, AND MORTIMER J. COHEN, OF NEW YORK, N. Y., ASSIGNORS, BY ASSIGNMENTS, TO SETH B. HUNT, TRUSTEE,

OF MOUNT KISCO, NEXV YORK.

PROCESS OF DIRECTLY ESTERIEYING OLEFINS AND PRODUCT THEREOF.

No Drawing.

0 all whom it may concern:

Be it known that we, Cameron Ennis and Mon'rmrnn J. COHEN, citizens of the United States, and residents of Montclair, county of Essex, and State of New Jersey, and New York, county of New York, and State of New York, respectively, have invented certain new and useful Improvements in Processes of Directly Esterifying Olefins and Products Thereof, of which the following is a specification.

Our invention relates to the esterification of olefins and the products of esterification.

One object of the invention is the provision of a process by means of which an organic acid, such for example, as acetic acid or formic acid, may be combined directly with an olefin or olefins, even in the presence of saturated hydrocarbon diluents, such, for example, as volatile hydrocarbons of the paraflin series or similar body or bodies.

Another object of the invention is the production of solvent mixtures, suitable for use in pyroxylin and related industries, directly from petroleum products containing saturated and unsaturated materials by the esterification of the unsaturated olefins without the necessity of making a separation between such materials, although if desired, the esters and the saturated material, as gasolene, may be separately recovered.

While our invention may be applied to olefin materials separate from saturated petroleum materials, as gasolene and the like, it is preferably carried out with a mix ture of saturated and unsaturated materials, such as cracked gasolene, obtained by cracking heavier petroleum oils in any of the various modes available therefor, or other petroleum products containing mixtures of saturated and unsaturated material, as still gas condensate, and other similar bodies containing substantial quantities of the unsaturated olefins.

We have found that when olefins or mixtures of such saturated and unsaturated materials are treated with an organic acid, such as acetic acid, under apparently favorable conditions for reaction, such as the provision of an excess of the acid, or the application of heat, as by means of heating under a reflux condenser over considerable periods, substantially no esterification of the olefins takes place, and that in the absence of suit- Specification of Letters Patent.

Patented Jan. 11, 1921.

Application filed June 30, 191%. Serial No. 106,769.

able material as hereinafter set forth, in addition to the olefins and the organic acid or acids, which it is desired to unite, no sub stantial results can be obtained in the way of combining the organic acid with the unsaturated material.

lVe have found, however, that when a proper activating third material or sub stance is present, such direct addition of the organic, as acetic, acid or a mixture of organic acids to the olefins may be effectively carried out, and we have found that among the activators having this effect concentrated sulfuric acid up to, say, about 10% or more of the acetic acid used is effective as an activator in bringing about the desired reac tion. Other activators may, of course, be used, as, for example, hydrochloric acid, phosphoric acid and other materials and substances which have the effect of bringing about the desired reaction.

The presence of water appears to be unfavorable to such direct addition reaction, and for this reason the organic acid used should be in substantially anhydrous state, as when acetic acid is used the acid should be glacial acetic, and for other organic acids the acid should be as nearly as possible in the anhydrous state.

The glacial acetic acid used, when an acetic ester or esters is or are to be made, may be either in substantially pure form, as may be prepared in advance, or a salt of acetic acid may be utilized, as calcium acetate, and this salt reacted upon by an acid as sulfuric acid, forming a pasty mixture of calcium sulfate and the glacial acetic acid.

In working on mixtures of saturated and unsaturated materials, such as cracked gasolene, containing olefins with acetic acid, such petroleum mixture and the glacial acetic acid or glacial acid containing material such as prepared from calcium acetate in the manner described are mingled together, as by adding either to the other, the acetic acid being preferably in excess of the amount required for acetylation of the olefins of the concentrated sulfuric acid is present to take up any water which may be present without material dilution of the sulfuric acid to, say, below specific gravity of 1.7 or at least a point not as low as specific gravity 1.57. The activator may be applied when a salt of the organic acid is utilized, as above, by providing a suitable excess of sufficiently strong sulfuric acid in making the glacial acetic acid, it being unnecessary in such case to supply the activating sulfuric acid separately.

These materials may be placed in an apparatus such a digester equipped with a reflux condenser, and after heating, say, for a period of a couple of hours or so, and under atmospheric pressure or in some cases under super-atmospheric pressure, the esterfication of the olelins by the organic acid will have progressed. in large measure or to substantial completion.

After the reaction has been completed to a sufficient extent the excess acetic acid and sulfuric acid may removed by washing, and the wash waters may be siphoned or otherwise taken off and the acids suitably recovered, if desired, and the salt, as calcium sulfate, if present, may be separated out as by centrifuging, filtration and the like operations, and the materials remaining, consisting in part or principally of the esters of the various oleiins, which, in the case mentioned, are the acetates, the saturated hydrocarbons originally present with traces of free oleiins remaining and small quantities of polymers of the olefins and sulfonated tarry bonies formed by the action of the sulfuric acid on the olefins, be subjected to fractional distillation and separated. If a fraction of cracked material is used having a boiling point of, say, below 100 C, the acetates corresponding to the olefins thereof boil approximate between 100 and 200 (1., generally above 115 C., so that the material going over up to, say, 100 C. consists principally of unsaturated hydrocarbons witn traces of olefins in their unchanged condition, and at temperatures of 115 and above the acetates may be separated and at substantially higher points the polymerized bodies, which consist of heavier oils, as kerosene, lubrieating oil and the lilac, leaving the tarry and sulfonated bodies in the condenser and which may be discarded or distillation carried on until the residue has been distilled or coked.

Or to obtain the acetates in substantially pure form separation by sulfuric acid of sp. gr. 1.57 may be resorted to in place of sepa ration by fractional distillation, the esters being soluble in sulfuric acid of this strength in which the hydrocarbons, includ-' ing such oleiins as may be present, are in soluble may be separately drawn ofi- By then diluting the sulfuric acid solution of esters to a point to bring the acid sub stantially below sp. gr. 1.57 the esters are separated from solution and form a top layer which may readily be drawn off or beneath which the weak acid may be drawn off from below; Then if desired the esters may be further purified by distillation and any traces of esters left in the weak acid may be similarly recovered as well as any esters left in the hydrocarbon material. The dilute acid may be concentrated for reuse.

in the above and other ways substantially pure esters may be obtained and separately reco ered either singly or as a mixture of esters from olefins or mixtures from hydrocarbon materials containing olelins or mixtures of olefins. 1

t is not essential, however, that there be such separation from the saturated gasolene or other saturated material, for in many arts, as in the dissolving of guncot-zon, it

common to resort to the use of mixed solvents containing a substantial quantity of saturated material such as gasolcne, and for such uses suitable mixed solvents may be prepared directly without the necessity of resorting to separation work such as described.

in the production of such ready mixed solvents the fact that the cracking process may be controlled so to govern the proportion of olefins produced is of importance. As is well known, cracking under comparatively low pressures tends to produce cracked ma terial rich in oleiins, while higher pressures tend to produce a relatively larger proportion of saturated material, and there are or conditions subject to control which t the relative proportions of saturated and unsaturated materials yielded and which need not be referred to in detail here, important fact being that it is possible control relative proportions 'of saturated and unsaturated materials produced. .ziccordingly, when a solvent containing specified proportions of, say, gasolene and es of the olefins is desired, it is only sary to provide a cracked gasolene consubstan ially the desired proportion the y, of course, the necessity of separating out any excess organic acid used, together with the activating material, as sulfuric acid, and the removal of any salts, as calcium sulfate, which may be present, or, if desired, the hydrocarbons and esters may be separately recovered, and when separately and sufficiently freed of undesirable materials may again be commingled to serve their solvent uses, with or Without the addition of other solvents, as in a case Where a more complex solvent formula is being followed. In this way very substantial economies in the production of mixed solvents may be effected.

The direct production of esters by the 5 union of an organic acid with the olefins and the obtaining of results such as outlined above is dependent upon the presence of an activating material in bringing about the reaction. As such activating material in the case of sulfuric acid referred to is substantially completely recovered, its action may be considered at least in a broad sense to be that of a catalyzer, and it is with this property in View of bringing about the de sired reaction while still being recovered in substantially its original condition that the term catalyzer is made use of in our claims. By such use, however, we are not to be understood as excluding the possibility of intermediate reactions taking place, the ultimate result of which may be, so far as the activator is concerned, to restore it to its original condition when the desired reaction resulting in the addition of the organic acid or acids to the olefin or olefins has been effected. Thus when using sulfuric acid in this capacity, alkyl sulfuric acid may be formed in some cases as an intermediate product.

We are not to be limited by the following example given as an illustration and for affording a clear understanding of one way in which the invention may be carried out. For example, other activators may be used than stated, so long as they have the effect of bringing about the desired direct reaction, and other organic acids and hydrocarbon materials may be used, and when sulfuric acid is used as an activator substantially smaller quantities than stated may be used, so long as the organic acid is kept substantially anhydrous. We have obtained good results with lesser quantities of sulfuric acid than 10%, and, if desired, more of the sulfuric acid may be used, it being desirable, however, not to make use of unduly large quantities of such mineral acid because of the tendency in such case of the olefins to become sulfonated and to produce objectionable tarry materials and heavy polymers of the olefins, which are preferably avoided so far as may be.

Following is an example showing one way in which the invention may be carried out:

A mixture was made of about 20 parts of cracked petroleum material boiling below 100 0., about 100 parts of glacial acetic acid and about 10 parts of sulfuric acid of 1.8 specific gravity. The mixture was homogeneous and clear and on heating assumed a dark greenish color. The entire mass was heated under a reflux condenser for three hours and at the end of this time was washed with water to remove any excess of sulfuric 6 acid and glacial acetic acid. The remaining oil, which was dark red in color, was treated with sodium carbonate solution to neutralize any excess acid retained. This oil had the odor of the acetates and its saponification number was equal to 17 1, which indicates 7o 45% acetate content referred to hexyl acetate. It is evident then. from the foregoing acetate content that practically 100% conversion was obtained, viz: Substantially all the olefin material contained in the origi nal cracked oil amounting to approximately 45% was converted into acetate. This oil dissolved pyroxylin very rapidly and on distillation the distillate was water-white, the boiling points of the product lying mainly between 125460. Ready separation was made by this simple distillation method, since the original cracked material boiled mainly below 100 and contained principally simple normal olefins. However, if 5 contaminated by unsaturated hydrocarbons retained, they may be separated out with sulfuric acid of 1.57 sp. gr., which may be added to the mixture of acetate and hydrocarbon oil, the former being dissolved by the sulfuric acid and the latter left untouched and subsequently separated and the mixture of acetates recovered by simply adding to water and collecting the liberated acetates.

Where adding one material to another is referred to in our claims, the use of this term or similar expression includes bringing the materials together in any preferred way, or in any order; and by the use of the term heating in our claims is meant the application of heat sufficient to bring about the desired reaction.

Having thus described our invention, we claim:

1. The process of making ester material which consists in combining by heating a fatty acid with an olefin hydrocarbon in the presence of an acid catalyzer.

2. The process of making ester material which consists in combining, by heating at atmospheric pressure, substantially anhydrous acetic acid with an olefin hydrocarbon in the presence of a small quantity of sulfuric acid.

3. The process of making composite ester material which consists in combining, by heating at atmospheric pressure, substantially anhydrous acetic acid with a complex mixture of olefin hydrocarbons in the presence of sulfuric acid.

t. The process of making solvent material which consists in combining an organic acid with a complex mixture of olefin hydrocarbons in the presence of a substantial portion of saturated hydrocarbons by heating with a catalyzer.

5. The process of making solvent material which consists in directly uniting by heating an organic acid with the olefins contained in cracked gasolene in the presence of an acid catalyzer.

6. The process of making solvent material which comprises converting cracked gasolene containing saturated and unsaturated hydrocarbons into a mixture consisting substantially of saturated gasolene and acetates corresponding to unsaturated hydrocarbons by heating with substantially anhydrous acetic acid on the unsaturated hydrocarbons in the presence of a mineral acid catalyzer.

7. The process of making solvent material which comprises directly converting cracked gasolene containing saturated and unsaturated hydrocarbons into a mixture consisting substantially of saturated gasolene and acetates corresponding to unsaturated hydrocarbons by heating such gasolene with acetic acid at substantially atmospheric pressure in the presence of a catalyzer comprising sulfuric acid.

8. The process of making solvent material which comprises directly converting cracked gasolene containing saturated and unsaturated hydrocarbons into a mixture consisting substantially of saturated gasolene and acetates of unsaturated hydrocarbons by heating with substantially anhydrous acetic acid at atmospheric pressure in the presence of a small quantity of sulfuric acid not exceeding 10% of the acetic acid used.

9. The process of making solvent material which comprises heating a hydrocar-- bon liquid, containing a substantial proportion of olefin hydrocarbons, with an excess of acetic acid, in presence of sulfuric acid.

10. A mixed solvent comprising saturated hydrocarbons, and a mixture of the esters corresponding to the olefins of cracked gasolene.

11. A mixed solvent comprising saturated hydrocarbons, and a mixture of the acetates porresponding to the olefins of cracked gasoene.

In testimony that We claimthe'foregoing, we hereto set our hands, this 28th 'day of June, 1916.

GARLETON ELLIS. MORTIMER J. COHEN.