US3456027A - Aromatic hydrocarbons alkylated with normal butene polymers and the method of preparing the same - Google Patents

Description

United States Patent 3 456,027 AROMATIC HYDROCARBONS ALKYLATED WITH NORMAL BUTENE POLYMERS AND THE METH- OD OF PREPARING THE SAME George S. Cnlbertson, Whiting, and Albert R. Sabol and Robert E. Karll, Munster, Ind., assiguors to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Filed July 18, 1966, Ser. No. 565,731

' Int. Cl. C07c 3/56, 3/18 U.S. Cl. 260-671 2 Claims ABSTRACT OF THE DISCLOSURE Alkyl-substituted aromatic hydrocarbons prepared by reacting aromatic hydrocarbon and normal butene polymers having a molecular weight of about 200-800 under liquid phase alkylation conditions in the presence of aluminium chloride.

This invention relates to the alkylation of aromatic hydrocarbons. More particularly, it relates to the alkylation of aromatic hydrocarbons with olefinic hydrocarbons of high molecular weight to yield alkylates whose sulfonates are preferentially soluble in hydrocarbon oils.

The present invention finds its preferred application in the alkylation of aromatic hydrocarbons, particularly monocyclic aromatic hydrocarbons, with aluminum chloride. In this type of alkylation reaction, olefinic hydrocarbons having less than about 15 carbon atoms in the molecule react quite smoothly, rapidly, and in good yields, and require the employment of a relatively small proportion of an aluminumchloride catalyst, e.g., in the range of about 0.5 to about percent by weight based on olefinic hydrocarbons. However, higher branched chain olefinic hydrocarbons, by which we mean branced chain olefinic hydrocarbons having at least 15 carbon atoms, especially 20 or more carbon atoms, e.g., 25, 30, 40, or 40 carbon atoms in the molecule, do not alkylate well, that is to say, they require relatively gross amounts of aluminum chloride catalyst, long reaction periods and afford relatively poor yields. Attempts to overcome the sluggish behavior of such higher olefinic hydrocarbons in these alkylation reactions by the employment of more severe operating conditions, such as high alkylation temperatures, high proportions of catalysts, or long reaction periods are unsuccessful. Failure to improve the alkylation reaction by the selection of relatively severe operating conditions may be attributed primarily to the fact that these conditions induce decomposition of such higher olefinic hydrocarbons to produce products having both more and less carbon atoms in the molecule than the olefinic feedstock, and these degradation products may then alkylate the aromatic hydrocarbon to produce nondescript alkylates of wide boiling range containing a greatly reduced proportion of the desired alkylation product. Also, severe operating conditions tend to destroy the alkylate produced from the feedstocks.

This invention is concerned primarily with the production of alkyl aromatic hydrocarbons, particularly monocyclic aromatic hydrocarbons, having one or more side chains containing at least 15 carbon atoms. Alkyl aromatic hydrocarbons of this description are eminently suitable for sulfonation to yield sulfonic acids whose salts, i.e., soaps, are either preferentially soluble in hydrocarbon oils or highly soluble in hydrocarbon oils and quite insoluble in water at ordinary temperatures. These soaps are capable of specialized applications which necessitate the placement of rigid specifications on the soaps, one of the specifications being the absence of preferentially water soluble soaps.

It is an object of the present invention to provide a "ice method of preparing butene polymer alkylated aromatic hydrocarbons without obtaining undesirable degradation products. It is another object of this invention to provide a process for the alkylation of monocyclic aromatic hydrocarbons with butene polymers having a molecular weight from about 200 to about 800 to produce alkylated aromatic hydrocarbons whose alkyl side chains have molecular weights substantially the same as the molecular Weights of the polymer reactants. A further object of the invention is to provide a stable butene polymer alkylated benzene suitable for sulfonation to yield sulfonic acids, the salts of which are preferentially oil-soluble. Other objects and advantages of the invention will become apparent as the description thereof proceeds.

In the preferred embodiment, this invention relates to the alkylation of an aromatic hydrocarbon, particularly a monocyclic aromatic hydrocarbon with a selected mixture of normal olefinic hydrocarbons to produce alkylates of relatively narrow boiling range and restricted variation in the number of carbon atoms in the molecule. More particularly, the invention relates to the alkylation of benzene or similar hydrocarbons with a mixture of normal butene polymers having a molecular weight in the range of from about 200 to about 800. Such polymers are preferably prepared by the polymerization of a petroleum refinery stream containing normal butenes and essentially free of isobutylenes. A typical such refinery stream essentially free of isobutylenes, contains from about 11% to about 13% butene-l, from about 8.5% to about 10.5% cis-2- butene and from about 13.5% to about 16% trans-Z-butone, the remaining components being substantially C to C aliphatic hydrocarbons. A method of preparing butene polymers essentially free of isobutylene polymers from a refinery stream containing butenes as well as isobutylenes is described and claimed in copending U.S. application Serial No. 564,218, filed July 11, 1966, of John C. Heidler and Robert J. Lee, entitled Process For Producing Normal Butene Polymers, and assigned to the assignee of this application.

Polymers having molecular Weights of from about 200 to about 800, prepared by the polymerization of a mixture of olefinic and alkyl hydrocarbons containing from about 11% to about 13% butene-1, from about 8.5% to about 10.5% cis-Z-butene and from about 13.5% to about 16% trans-Z-butene, and essentially free of isobutylenes, are referred to hereinafter as normal butene Polymers.

Suitable aromatic hydrocarbons are monocyclic aromatic hydrocarbons, particularly benzene and alkylsubstituted benzenes, such as toluene, xylene, cumene, npropyl benzene, and the like.

The alkylation is carried out in the presence of well known Friedel-Crafts catalysts, and preferably aluminum chloride. If desired, in conjunction with the catalyst there may be used a minor amount of a promoter such as hydrogen chloride or an alkyl chloride, such as, for example, isopropyl chloride. From about 0.5% to about 5% of the catalyst, e.g., aluminum chloride, based on the normal butene polymers, are used.

Alkylation of the aromatic hydrocarbons with the aforesaid normal butene polymers is effected, in the liquid phase, at temperatures in the range of from about 0 F. to about 100 F., and preferably from about 30 F. to about F. The alkylation is usually conducted at atmospheric pressure, although higher pressures, e.g., about 50 to 500 psi. may sometimes be necessary or convenient.

Briefly, the alkylation is carried out by introducing a portion of the aromatic hydrocarbon, e.g., benzene, and the catalyst, e.g., aluminum chloride, into a suitable reactor, and slowly adding thereto a blend of the remaining portion of the artomatic hydrocarbon and the normal butene polymer, while vigorously stirring the reaction mixture. After completion of the reaction, the reaction mixture is allowed to settle, preferably in a settling zone, to permit the separation of aluminum chloride and aluminum chloride-hydrocarbon complex formed during the alkylation. If desired, after the removal of the bulk of the complex, the alkylation product may be freed of any occluded complex by treatment with anhydrous ammonia in accordance with the teachings in U.S. Patent 3,121,125, issued Feb. 11, 1964, to Gus Nichols. Treatment with the anhydrous ammonia forms a solid aluminum chloride-ammonia complex which can be settled and separated from the alkylation product. The alkylation product, after removal of the complex, is filtered through a suitable filtering medium, such as fullers earth or a diatomaceous earth, to remove any solid materials which may be occluded therein, and the filtrate heated to distill off excess unreacted hydrocarbons. The alkylate bottoms are then fractionated at suitable temperatures to obtain fractions of the desired molecular weights. If desired, the alkylates may be filtered through a suitable medium, such as Celite.

The following specific examples illustrate the process of the present invention. In these examples, the normal butene polymers employed were obtained, as described and claimed in the aforesaid co-pending application, by the aluminum chloride polymerization of a petroleum refinery stream having the following approximate composition:

Percent Propane 2.7 Propylene 0.7 n-Butane 18.3 Isobutane 40.4 Butene-l 12.0 cis-Z-butene 9.4 trans-2-butene 14.7 Isobutylene 0.6 Pentane 1.2

The polymers obtained were normal butene polymers essentially free of isobutylene polymers, and had molecular weights of about 336 and about 415. The 336 molecular weight polymer is referred to hereinafter as No. 1 Polybutene, and the 415 molecular weight polymer as N o. 2 Polybutene,

EXAMPLE I Step 1.One hundred and ninety-five grams (2.5 moles) of benzene and 3 grams (2.0% based on polymer) or A101 were added to a reactor.

Step 2.A blend of 150 grams (0.45 mole) No. 1 Polybutene and 195 grams (2.5 moles) benzene was slowly added to the mixture of Step 1, and the reactor contents vigorously stirred at a temperature of 70 F. Addition of the blend was completed in 30 minutes and the mixture stirred for an additional 30 minutes.

Step 3.At the end of one hour the product in the reactor was transferred to a separator or settler and permitted to settle for 45 minutes and the AlCl -hydrocarbon complex, formed in the reaction of Step 2, settled out and removed.

Step 4.Occluded AlCl still in the reaction product, after removal of the AlCl -hydrocarbon complex, was removed by glowing the reaction product with anhydrous ammonia to form a solid AlCl -NH complex, and the mixture filtered to remove the complex.

Step 5.The filtrate of Step 4, containing alkylate and unreacted benzene, Was heated to 250-300 F. and the unreacted benzene distilled off.

Step 6.After removal of the unreacted benzene, the bottoms were heated to a temperature of 450 F. while blowing with nitrogen to strip off low molecular weight alkyl benzenes (29 grams, 19.3% based on polymer charged) formed as by-products in the alkylation step;

the maximum overhea temp ratu e was 260270 F.

Step 7.The recovered alkyl benzene bottoms had a molecular weight of 361 with a yield of 88% EXAMPLE II Step 1.-One hundred and ninety-five grams (2.5 moles) of benzene and 4.1 grams (2.0% based 'on polymer) of AlCl were added to a reactor.

Step 2.A blend of 207 grams (0.5 mole) of No. 2 Polybutene and grams (2.5 moles) benzene was slowly added to the mixture of Step 1 and the reactor contents vigorously stirred at a temperature of 70 .F. Addition of the blend was completed in 30 minutes and the mixture stirred for an additional 30 minutes, and 3.0 grams (1.45% based on the polymer) of water were added to the reactor to deactivate the AlCl catalyst.

Step 3.The product in the reactor was transferred to a separator and permitted to settle for 45 minutes, and the AlC l -hydrocarbon complex, formed in the reaction of Step 2, settled out and removed.

Step 4.-Occluded A101 still in the reaction product, after removal of the AlCl -hydrocarbon complex, was removed by blowing the reaction product with anhydrous ammonia to form a solid AlCl -NH complex, and the mixture filtered to remove the complex.

Step 5.The filtrate of Step 4, containing alkylate and unreacted benzene, was heated to 250-300 F. and the unreacted benzene distilled off.

Step 6.-After removal of the unreacted benzene, the bottoms were heated to a temperature of 450 F. while blowing with nitrogen to strip ofi? low molecular weight alkyl benzenes (4.3% based on polymer formed as byproducts; the maximum overhead temperature was 260- 270 F.

Step 7.The benzene alkylate bottoms was filtered while hot through Celite. Eighty-seven percent of the desired alkyl benzene having a molecular weight of 373 was recovered.

- EXAMPLE III The alkylation in this example, carried out as described in Example II, except that 3.1 grams (1.5% based on polymer) AlCl was used, yielded 9.6% (based on polymer) of undesired low molecular weight benzene alkylate, and'79% of the desired alkyl benzne having a molecular weight of 413.

Similar alkylations using isobutylene polymers, instead of the normal butene polymers of comparable molecular weights, leads to substantially greater yields of undesired low molecular weight alkyl benzenes and poor yields of alkyl benzenes of desired usable higher molecular weight. Aluminum chloride in the presence of benzene rapidly depolymerizes isobutylene polymer into polymers of :relatively low molecular weight and monomer molecules, thus resulting in excessive amounts of benzene alkylates of undesired low molecular Weight.

It will be apparent that the present invention provides an improved process for the alkylation of aromatic hydrocarbons, particularly to produce higher alkyl aromatic hydrocarbons suitable for sulfonation to form oil-soluble or preferentially oil-soluble sulfonates.

Percentages given herein are Weight percentages unless otherwise stated.

While particular embodiments of the invention have been described, it is to be understood that the invention is not limited thereto, but covers such modifications and variations as come within the spirit and scope of the appended claims.

We claim:

1. The process of alkylating benzene with olefin polymers having a molecular Weight of from about 200 to about 800 in the presence of aluminum chloridecatalyst, whereby the yield of undesired low molecular weight alkylates is minimized and the yield of desired high molecular weight alkylates maximized, which process comprises reacting benzene in the presence of an aluminum chloride catalyst with normal butene polymers having molecular weights in the range of from about 200 to about 800, and recovering high molecular weight alkyl benzene from said reaction, said normal butene polymers being obtained by the polymerization, in the presence of a Friedel-Crafts catalyst, of a hydrocarbon mixture, essentially free of isobutylene and consisting essentially of from about 11% to about 13% butene-l, from about 8.5% to about 10.5% cis-2-butene, from about 13.5% to about 16% trans-2- butene, and the remainder C3"C5 aliphatic hydrocarbons.

2. The process of claim 1 wherein the normal butene polymers are obtained by the aluminum chloride polymerization of a hydrocarbon mixture having the following approximate composition:

Percent Isobutane 40,4 Butene-l 12.0 cis-Z-butene 9.4 trans-2-butene 14.7 Isobutylene 0.6 Pentane 1.2

References Cited UNITED STATES PATENTS 3,104,267 9/ 1963 Antonsen et al 260671 3,108,145 10/1963 Antonsen 260-671 3,315,009 4/1967 Englebrecht et al. 260671 DELBERT E. GANTZ, Primary Examiner CURTIS R. DAVIS, Assistant Examiner "H050 I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 5 7 Dated July 15, 1969 Inventor(s) George S. Culbertson, Albert R. Sabol, and Robert E. Karll It is certified that error appears in the above-identified petent and that said Letters Patent are hereby corrected as shown below:

r- Column 1, line 3 "eluminumchloride" should read aluminum chloride line 39, +0" (second occurrence) should read 5O Column 3, line 50, "or" should read of Column line 31, "polymer formed" should read polymer) formed line 4-1, "A1012" should read A101 line +3, "benzne" should read benzene line 51, "polymer" (first occurrence) should read polymers SIGNED AND SEALED MAR 2 41970 Attest:

Edward Matcher WILLIAM E. scauxm. Aumfing ()ffi gg Commissioner of Pat n