US2413260A - Refining of aromatic hydrocarbons with acid-acting metallic halides - Google Patents

Description

Patented Dec. 24, 1946 REFINING F AROMATIC HYDROCARBONS WITH ACID-ACTING METALLIC HALIDES Frank J. Soday, Swarthmore, Pa., assignor to The United Gas Improvement Company, a corporation of Pennsylvania No Drawing. Application February 10, 1943,

Serial No. 475,438

10 Claims. (01. 260-674) This invention is concerned with the refining of aromatic hydrocarbons. More particularly, this invention removal of unsaturated hydrocarbons from aromatic hydrocarbons, or fractions and/or mix-' tures containing aromatic hydrocarbons.

An object of the present invention is the removal of impurities from aromatic hydrocarbons by the application thereto of successive portions of acid-acting metallic halides. Another object of the invention is the provision of methods for the conversion of unsaturated hydrocarbons present in aromatic hydrocarbon fractions into resinous and/or oily polymers possessing considerable industrial utility.

Other objects and advantages of the invention. will be apparent to those skilled in the art upon an inspection of the specification and claims.

In the various processes for the manufacture of artificial gas such as oil gas, carburetted water gas, or coal gas, considerable quantities of tar are produced, and the gas contains substantial quantities of readily condensible materials.

These condensates, as well as the light oil obtained upon distillation of the tar, are sources for many hydrocarbons, including aromatic hydrocarbons such as benzene, toluene, xylene, and

the miscellaneous hydrocarbons which are commonly designated as solvent naphtha.

With ordinarymethods of fractional distillation as now practiced, it is impossible to separate these compounds in a substantially pure state because of the presence of other -'materials which, are either of similar boiling point or are capable of forming azeotropic mixtures with the desired hydrocarbon. The impurities present in the aro- Y matic hydrocarbon fractions are essentially unsaturated in nature, and are usually present in considerable quantities.

Typical aromatic fractions obtained by the fractionation of light oil obtained in the pyrolysis 'of petroleum 'oil will contain from 5 to by weight of unsaturated hydrocarbons, which is unusually high. These unsaturated hydrocarbons must be removed from the aromatic fractions before they can be used for many. industrial purposes. This has proved to be a very difllcult undertaking due to the necessity of removing unusually large quantities of unsaturated hydrocarbons from the respective fractions.

Theprocesses which have been developed for the purification of aromatic hydrocarbon fractions with polymerizing agents, such as AlCla, are of particular interest as they offer a convenient method of converting the unsaturated hydrocarpertains to the metallic halide such as aluminum chloride does a not refine the aromatic hydrocarbon sufficiently bons present in the aromatic hydrocarbon fractions into products which have a potential commercial value. In contrast to this, the usual" process employed for the purification of crude aromatic hydrocarbon fractions, namely, processes'based upon the use of sulfuric acid, results in the production of a black, viscous acid sludge of no value. In many cases, the disposal of this acid sludge is a very serious problem, as it cannot be. indiscriminately dumped due to its highly corrosive nature.

I have found that a single treatment ofa crude aromatic fraction with 'an'acid-acting to permit it to pass the usual commercial specifications. In addition, the high temperatures customarily' employed 78 0.) results in the conversion, of the unsaturated hydrocarbons present to darli, viscous polymers of low molecular weight.

I have discovered that crude aromatic hydro-. carbon fractions can be refined with acid actin metallic halide catalysts such as aluminum chloride to meet. the most exacting industrial specifications by conducting the refining operations 1.

in at least two stages, preferably removing the resinous polymers formed between the successive treating stages. In addition, the unsaturated hydrocarbons present 'in the crude'aromatic fraction areconverted into two valuable'products, namely, a high-melting resin of good quality, and an oily polymer. The process preferably is carried out at temperatures substantially below N The high melting resin is usually obtained dur ing the initial treating process and comprises the major portion of the'unsaturated hydrocarbons is formed from the remaining unsaturated hydrocarbons present in the crude fraction." By varying the treating process, it is possible to produce to obtain a mixture of oily polymers and high- .amixture of high-melting resin and oily polymer from the, initial refining step, the high-melting resin predominating in the mixture. It.is also possible to operate-the process in such a way as melting resin from the succeeding treating stages, the oily polymer predominating.

For certain industrial applications, the use of amlxture of these two polymers in a given proportion may be found to be more advantageous than the' use of ei'therpolymer alone. The proc- -ess described herein .can be controlled in such a way asto produce a mixture ofpolymers of the desired composition. For certainother appllcations, however, the high-melting resin or the oily polymer may alone be required,'in which case they may be separated from their respective mix-.

tures, preferably by distillation. Distillation with Y steam, preferably under reduced pressure, has 1 been found to be a very satisfactory method.

By' a suitable choice of operating conditions, it is possible tobbtain the high melting resin in relais removed before adding a fresh quantity of catalyst. Apparently the hydrocarbon polymer present in the solution diminishes the activity of the freshly-added catalyst, such as by the formation of loose complexes between the hydrocarbon polymer-AlCh complexes present in the solution and a portionor all of the new charge of aluminum chloride.

tively pure form from the initial refining opera tion. In addition, refining process canbeopers from the succeeding stages of the treatment con-- sists almost entirely or the oily polymer. This ated in such a way that the product obtained procedure eliminates the necessity of separating the polymers obtained from the process.

On the other hand. the refining of crude aromatic hydrocarbon fractions with acid-acting metallic halides such as aluminum chioridein successive stages, but without intermediate removal of the polymer formed during each of the treating stages, results in a mixture containing all of the high-melting resin and the oily polymers formed during the refining operations. In case it is desired to separate the components of this polymeric mixture, the distillation step previously described is preferably employed.

It has also been found that a multiple treating process in which the polymerized hydrocarbons are removed between the successive treating stages results in the production of refined aromatic hydrocarbons of better quality than the methoddiscussed in the preceding paragraph,

in which the polymer formed is only removed at the end of the treating process.

The improved efilciency of the multiple stage treating process over the single stage treating.

process is based upon the following theoretical considerations. The addition of an acid-acting metallic halide such as aluminum chloride to a system containing unsaturated hydrocarbons results in the primary formation of aluminum The quantity or acid-acting metallic halide such as aluminum chloride required for refining crude aromatic hydrocarbon fractions ranges from 0.5 to 5.0%, although from .1 to 3% will be found to be sufilcient in practical all cases. This quantity of catalyst is considerably less than the I quantity normally used'in the single stage aluminum chloride process.

Any desired treating temperature can be em- 9 ployed,'although temperatures in the range of 1 to 10 hours.

0-90 C. are more often used. I find that the use of treating temperatures in the range of 20-60 0., and more particularly in the range of 30-50 0., gives very satisfactory results. Adequate cooling provisions must be made in order to control the temperature within the limits desired. In J general, the use, of elevated treating temperatures results in a more complete removal of the unsaturated hydrocarbons present, but with the production of resinous polymers of inferior quality, while the use of very low treating temperatures results in an incomplete removal of the unsaturated hydrocarbonspresent, accompanied by the production of resinous polymers of excellent quality. The use of the preferred treating temperaof a good 1 tures will result in the production grade of refined aromatic hydrocarbons, as well as resinous products of good quality.

The treating time employed usually varies from treating periods results in the more complete chlorideunsaturated hydrocarbon complexes 1 which, in turn, act as the actual polymerizing agents. The reaction is of the chain type. the unsaturated hydrocarbons presentbecoming attached to the AlCl3 complex originally formed,

resulting in an increase in the length of the hydrocarbon chain attached to each aluminum chlo- I ride molecule. As the length of the hydrocar-- bon' chain increases, its activity proportionally decreases. Consequently, the rate of removal of unsaturated hydrocarbons from the solution to form resin decreases at a fairly rapid rate, and

. at the end of the treating process the point of minimum concentration of unsaturated hydrocarbons in-the solution coincides with the point of minimum catalytic activity. As a result the aromatic hydrocarbon, or aromatic hydrocarbon fraction, subsequently obtained contains considerable quantities of unsaturated hydrocarbons, and does. not meet the usual specifications for commercial grades of the corresponding refined aromatic hydrocarbons.

I The multiple-stage treating process counter-v acts the diminishedactivity of the catalyst near the end of the treating processby the addition of a fresh quantity of catalyst. The unpolymerized,

unsaturated hydrocarbons present in the solution at this point are then polymerized by the fresh catalyst.

As previously pointed out, the multiple-stage 1 treating process gives the best results if the polymer formed during th first stage of the process elimination of the unsaturated hydrocarbons present. v

' The refining agents which have been found to be of value in this process comprise the .acidacting metallic halides, as well as acid-acting metallic halide-organic solvent complexes.v Examples of these catalysts are A1013, FeClz, ZnCla,

AlBra, BF: BCla, AlCla.organic ether complex,

BFaorganic ether complex, and the like. Since the metallic halide is the active component whether or not it is in the form of a complex,

these catalysts are defined collectively as acid-- very narrow boiling cuts may be refined by this process, the aromatic hydrocarbons secured then requiring no further fractionation to meet the usual specifications for refined products.

The process has been found to be very satisfactory for the purification of benzene, toluene and xylene aromatic fractions.

The polymerized solution is usually treated with a hydrolyzing agent to decompose the catalyst present, followed by the separation of the insoluble material present by suitable means, such general, theuse of extended as filtration. The polymer is then separated from the refined hydrocarbon fraction, usually f by distillation. The aromatic fraction may then be fractionated in an efllcient column to produce the process. 1

Exmm 1 A 1500 cc. portion of an aromatic hydrocarbon fraction obtained by the condensation of oil gas, and containing 8.6% by weight of unsaturated hydrocarbons, was treated with 105 cc. of 96% H2804 (equivalent to 1.07 lbs. ofHzSOr per gallon) according to the standard method outlined in'the Gas Chemists Handbook. The solution was cooled and vigorously agitated by means of a turbo-mixer during the entire treating operation. The sludge was removed at the end of the acid treating process, the refined solution then washed with water, and then neutralized with a 30% solution of sodium hydroxide. The hydrocarbon fraction then was dried and fractionated in a Fenske-type column possessing 11 theoretical plates, using a reflux ratio of 10:1. The following results were secured.

A 2000 g. portion of the same aromatic fraction used in Example 1 was placed in a three-neck round bottom flask provided with a reflux condenser and an agitator. Approximately 86 grams of anhydrous aluminum chloride (4.3% byweight of the fraction to be refined) was added and the mixture agitated for a period of 3 hours at a temperature of 30-40" C. The temperature then was raised to 50 C. and the reaction continued for an additional period o'f'three hours. The polymerized solution then was treated with a 30% solution of sodium hydroxide, filtered,.and the mixture distilled on an oil bath at a temperature of 170 C. The distillate then was fractionated in the column previously described. The

following results were secured.

EXAMPLE 3 A 2000 g. portion of the same aromatic fraction.

used in Example 1 was treated with 20.0 grams of aluminum chloride (1.0% by weight of the' fraction to be refined) at a temperature of 20-30 C. for a period of one hour. The temperature then was increased to 50 C. and the treatment continued for an additional period or three hours.

An additiona1 1.0% portion ride (20.0 g.) was added to the reaction mixture at this point, and the treatment continued .for a further 3 hour period at a temperature or 50 C. The-solution then was neutralized with a 30% solution of NaOH, dried, and fractionated, in the manner previously described. The following re- Exmna 4 A 2000 g. portion of the same aromatic fractionused in Example 1 was treated with 20.0 g.

of AlCla (1.0% by weight of the fraction'to be refined) 'at a temperature of 20-35" C. during a period of 4 hours.

A slight excess of 30% NaOH solution was added to the reaction flask, and the mixture agitated for a period of two hours. The unreacted hydro-- carbon fraction was then separated from the resinous polymer by distillation, andthe distillate dried over lime.

The distillate was again treated with 20.0 g.

(1.0%) of A1013 for a period of approximately one hour at a temperature of 20-35" C. The temperature was increased to 50C. at this point and the reaction continued for an additional period or three hours. The polymerized solution was hydrolyzed with a 30% solution of NaOI-I, the unchanged hydrocarbon fraction separated from the resinous polymers, and the distillate dried over lime. It then was fractionated in the manner previously described. The following results were secured.

Per cent by Barretts Component weight of acid wash charge stock color 1. Distillate 87.0 (0) 2 benzol. 53. 6 1 l (0) 2 t01u0l- 19.6 1 2. Resinous polymers -13. 0

The data indicate that the refined be'nzol and toluol secured was of exceptional purity, as measured by the low acid wash colors of the respective fractions secured.

EXAMPLE 5 A 1500 cc. portion of an aromatic hydrocarbon fraction obtained by the distillation of tar obtained as a by-product in the oil gas process, and containing 8.6% by weight of unsaturated hydrocarbons, was treated with cc.-of 96.0% H2804 (equivalent to 1.07 lbs. of H2804 per gallon) according to the standard method described in the Gas Chemists Handbook. The solutionwas cooled and vigorously agitated during the entire treating process. The sludge was removed at the end of the acid treating process, and the refined solution then washed with water and neutralized with af 30% solution of sodium hydroxide. The hydrocarbon fraction thenwas dried and ractionated in a Fenske-type column possessing 11 theoretiof aluminum chlo- Per cent by I weight of Component chargestock co r a; 2 benzoL- 26. 3 6% 2 toluol--- 44. 3 5 udge 11 6 Exsuru: 6

A 2000 g. portion of the same aromatic fraction used in Example 5 was placed in a threeneck round bottom flask provided with a reflux condenser and an agitator. Approximately 86 g. of anhydrous AlCls (4.3% by weight of the fraction to be refined) was added and the mixture agitated for a period of 3 hours at a temperature of 30-40 C. The temperature then was raised to 50 C. and the reaction continued for an additional period of three hours. The polymerized solution then was treated with a 30% solution of sodium hydroxide, filtered, and the mixture distilled on an oil bath at a temperature of 170? C.

- The distillate then was fractionated in the column previously described. The results secured were as follows:

A 2000 3. portion of the same aromatic fraction used in Example 5 was treated with 20.0 g. of aluminum chloride (1.0% by weight of the fraction to be refined) at a temperature of 20-30 C. for a period of one hour. The temperature then was increased to 50 C. and the treatment continued for an additional period of three hours. An additional 1.0% portion of A1013 (20.0 g.) was added to the reaction mixture at this point. and the treatment continued for a further 3 hour .period at a temperature of 50 C.

The solution then was neutralized with a 307 solution of NaOH, dried, and fractionated in the manner previously described. .The following results were secured: I

Exmrns 8 A 2000 8. portion of the same aromatic fraction used in Example 5 was treated with 20.0 g. of AlCla (1.0% by weight of the fraction to be refined) at a temperature of 20-35 C. during a period of 4 hours.

A slight excess of 30 NaOH solution was added to the reaction fiask, and the mixture agitated for a period of two hours. The unreacted hydrocarbon fraction was then separated from the resinou's polymer by distillation, and the distil-' late dried over lime.

The distillate was again treated with 20.0 g.

8 I (1.0%) of MCI: for a period of approximately one hour at a temperature of 20-35' C. The temperature was increasedto 50 C. at this point and the reaction continued for an additional period 7 of three hours. The solution was hydrolyzed with a 30% solution of NaOH, the unchanged hydrocarbon fraction separated from the resinous p01- ymers, and the distillate dried over lime. It then was fractionated in the manner previously described. The following results were secured.

C ponent a id h charge stock cola- 1. Distillate 89.2 Ea) 2 benwL. 30.: 1 0) 2 toluol--- 45. 0 1 2. Resinous polymers 10.8

toluol secured was of exceptional purity, as measured by the low acid wash, colors of the respective fractions. 7

It will be noted that Examples 1 and 5 are ex.

.The data indicate that the refined benzol and amples of standard sulfuric acid refining methods. Examples-2 and 6 are examples of a singlestage A1013 treatment, Examples 3 and 7 are examplesof a two-stage AlCla treatment without intermediate removal of the polymer formed between the successive treating stages, and Examples 4 and 8 are examples of a-two-stage A101:

treatment with intermediate removal of the polymers formed in the treating process.

It will be noted also that only 2% of the cataiyst is required in Examples 3 and '7, as com- A sample of the resinous material obtained by the aluminum chloride treatment previously described 'Was steam distilled under reduced pressure. The resinsecured had a melting point of 147 C. as measured by the standard A. S. T. M. ball and ring method. 0 In this connection, it is well to point out that the resin obtained as a result of the refining process disclosed .herein contains substantial proportions of aromatic hydrocarbon residues. Presumably, the aromatic hydrocarbon reacts with at least a portion of theunsaturated hydrocarsuch reaction products to form resinous polymers. The presence of aromatic hydrocarbon residues in such'resinous polymers confers valuable soluility and stability characteristics thereto.

A standard 15 gallon varnish was prepared 1 Cobalt, manganese, and lead drier.

Cooking procedure The mixture of resin and China-wood oil was placed in a copper beaker and heated to atemperature of 400 F. during a period of 20 minutes. The mixture was then heated to a temperature of 560 F. during a period of 10 minutes. and held at this temperature for an additional period of 3 minutes. It was allowed to cool to 535 1"; held at this temperature for a period of 6 minutes, chilled to 400 F. (by partially immersing the beaker in water) and reduced byiadding the solpared with 4.3% in Examples 2 and 6, to secure products having better acid wash colors.

bons present, followed by the polymerization of anaaeo" vent naphtha. The drier was stirred into the I varnish when it reached room temperature.

The product was a clear, light colored yarnish with excellent coating properties. .It can be used to coat metals, wood. and other surfaces.

In addition to China-wood oil, other drying oils least one hour to, cause the formation of resinous polymer from a portion of said polymerizable unsaturated hydrocarbon material, neutralizing said suchas oiticica oil, perilla oil, linseedoiLisomerizedlinseed oil, dehydrated castor oil, soya bean oil, fish oil, sardine oil, menhaden oil, synthetic drying oils, and the like, may be employed inthe preparationof varnishes and other coating compositions irom my new resins.

Other ingredients also may be added to suchv compositions, such as solvents, plasticizing agents, pigments, driers, and the like.

In addition to removing unsaturated hydrocara catalyst, separating'said polymer and said' aromatic hydrocarbon material from the resulting reaction mass. and from each other, thereafter contacting said aromatic hydrocarbon material with a further quantity of from 1% to 3% by weight of said contaminated aromatic hdrocarbon material of aluminum chloride catalyst under temperature conditions in' the range of 20 C.

. to 60 C, for a period of at least one hour there- .by causing the formation of oily polymer from b the remaining polymerizable unsaturated arohung, the refining process described herein also While various procedures and formulas have' been particularly. described these are of course subject to considerable variation. Therefore, changes, omissions, additions, substitutions, and] or modifications may be made within the scope of the claims without departing from the spirit of the invention.

I claim:

. said contaminated benzene with from 0.5% tov benzene with afurther quantity of from 0.5% to.

1. A process for refining aromatic hydrocarbon material boiling below 400 C. and contaminated with polymerizable impurity of similar boiling point to said aromatic hydrocarbon material which comprises contacting said contaminated to 5.0% by weight of said contaminated aromatic hydrocarbon material of an acid-acting metallic.

halide catalyst at a temperature between 0C.

and 80 C. for a period of at least one hour thereby'causing the formation of resinous polymer from a portion of said impurity, neutralizing said catalyst, separatingsaid polymer and said aromatic hydrocarbon material from the resulting reaction mass and from each other, thereafter contacting said aromatic hydrocarbon material with from 0.5% to 5.0% by weight of said contaminated aromatic hydrocarbon material of additional acid-acting metallic halide catalyst at a temperature in the' range of 0 C. to 80 C. for a period of at least one hour to remove further'impurity in the form of oily polymer, neutralizing said additional catalyst and recovering said aromatic'hydrocarbon material in purified form from the resulting reaction mass.

2. A process for the purification of aromatic hydrocarbon material of the benzene series contaminated with impurity including polymerizable unsaturated hydrocarbon material of similar boiling point to said aromatic hydrocarbon material, said aromatic hydrocarbon material boiling below 400 0., which comprises contacting said contaminated aromatic. hydrocarbon material with from 1% to 3% by weight of said contaminated aromatic hydrocarbon material of aluminum chloride catalyst at a temperature in the range of 20 C. to 60 C. for a period of-at aromatic hydrocarbon material with from 0.5%

matic hydrocarbon material present, neutralizing said further quantity of catalyst and recovering said aromatic hydrocarbon material in more concentrated form from the resulting reaction mass.

3. A process for refining benzene contaminated impurity including polymerizable un- I saturated hydrocarbon material of similar boilwith ing point tobenzene, which comprises contacting 5.0% by weight of said contaminated benzene of an acid-acting metallic halide catalyst at a temperature in the range of 0 C. to C. for a period of one hour to-cause the formation of resinous polymer from atleast a portion of said unsaturated hydrocarbon material, neutralizing said catalyst, separating said polymer and said benzene from the resulting reaction mass and from each other, thereafter contacting said 5.0% by weight thereof of acid-acting metallic halide catalyst'at a temperature in the range of 0- C. to 80 C. for a period of at least one hour .to cause the formation of oily polymer from'the remaining unsaturated hydrocarbon -material,

neutralizing said further quantity of catalyst, and

recovering benzene in more concentrated form from the resulting reaction mass.

4. A process for refining toluene contaminate with saturated hydrocarbon material of similar boiling point to toluene, which comprises, contacting said contaminated toluene with from 0.5% to 5.0% by weight of said contaminated toluene of an acid-acting metallic halide catalyst at a temperature in the range of 0 C. to 80 C. for a,

period of at least one hour to cause the formation of resinous polymer from a portion of said unsaturated hydrocarbon material, neutralizing said catalyst, separating said polymer and said toluene from the resulting reaction mass and from each other, thereafter contacting said toluene with a further quantity of from 0.5% to 5.0% by weight thereof of acid-acting ,metallic halide catalyst at a temperature in the range of 0 C. to 80 C. for a, period of at least one hour to cause the formation of oily polymer from the remaining unsaturated hydrocarbon material, neutralizing said further quantity of catalyst, and recovering toluene in more concentrated form from the resulting reaction mass. 3 r

5. A process for refining a mixture of benzene and toluene contaminated with impurityincluding polymerizable unsaturated aromatic hydrocarbon material of similar boiling point to said mixture, which comprises contacting said contaminated mixture of benzen and toluene with from 0.5% to 5.0% by weight of said contaminated mixture of an acid-acting metallic halide catalystat a temperature in the range of 0 C. to 80 C. for a period of one hour to cause the formation of resinous polymer from at least impurity including polymerizable unhydrocarbon materiaLneutralizing said catalyst, separating said mixture of benzeneand toluene from the resulting reaction mass including said i polymer, thereafter contacting said mixture of benzene and toluene with a further quantity of from 0.5% to 5.0% by weight thereof of acidacting metallic halide catalyst at a temperature inthe range of C. to 80- C. for a period of at least one hour co cause the formation of oily polymer from the remaining polymerizable unsaturated hydrocarbon material, neutralizing said further quantity of catalyst and recovering a mixture of benzene and toluene in more concentrated form from the resulting reaction mass.

6. A process for'the recovery of refined benzene from a light oil fraction containing benzene together with polymerizable unsaturated hydrocarbon material of similar boiling point to said benzene, which comprises contacting said fraction with from 0.5% to 5.0% by weight of said light oil fraction of aluminum chloride at a temperatur in the range of 0 C. to 80 C. for a period of least one hour thereby causing the,

formation of resinous polymer from a portion of said polymerizable unsaturated hydrocarbon material, neutralizing said aluminum chloride, separatingsaid fraction from the resulting reaction mass including said polymer, thereafter contacting said fraction witha further quantity of from 0.5% to 5.0% by weight of said light oil fraction of aluminum chloride at a temperature in the range 0 C. to 80 C. for a period of'at least one hour thereby causing the formation ofoily polymer from the remaining .polymerizabie unsaturated hydrocarbon material present, neutralizing said further quantity of aluminum a portionof said polymerizable unsaturated from portion of said impurity, neutralizing said 'r' l2 8. A process for the recovery of a mixture of benzene and toluene from alight oil fraction containing the same together with polymerizabie unsaturated hydrocarbon material of similar boiling point to said mixture which comprises contacting said fraction with from 0.5% to 5.0% by weight of said light oil fraction of aluminum chlorde at a temperatur in the range of 0 C. to

80 C. for a period of at least one hour thereby causing the formation of resinous polymer from a portion of said polymerizable unsaturated hydrocarbon material, neutralizing said aluminum chloride, separating said polymer and said fraction from the resulting reaction-mass and from each. other, thereafter contacting said fraction with a further quantity of from 0.5% to 5.0% by weight of said light oil fraction or alu-' minum chloride at a temperature in the range of 0 C. to 80 C. for a period of at least one hour thereby causing the formation of oily polymer from the remaining polymerizable unsaturated hydrocarbon ma erial present, neutralizing said further quantity of aluminum chloride, and recovering a mixture of benzen and toluene in 5 more concentrated form from the resulting reaction mass. i

- A process for refining aromatic hydrocarbon material boiling below 400 C. and contaminated with polymerizable impurity of similar boiling point therewith, which comprises contacting'saidcontaminated aromatic hydrocarbon material with an acid-acting metallic halide catalyst u'n der conditions causing the formation of polymer catalyst, separating said aromatic hydrocarbon material from the resulting reaction mass includchloride and recovering benzene in more concentrated form from the resulting reaction mass.

' 7. A process for the recovery of refined toluene from'a light oil 'fraction containing toluene to-.

gether with polymerizable unsaturated hydrocarbon material of similar boiling point to said toluene, which comprises contacting said frac-' tion with from 0.5% to. 5.0% by weight of said light oil fraction of aluminum chloride at a-temvperature in the range of 0 C.'to 80 C. for a said polymerizabieunsaturated hydrocarbonmaterial, neutralizing said aluminum-chloride, seping 'saidpolymer, thereafter contacting said aromatic hydrocarbon material with additional acidacting metallic, halide catalyst under conditions causing the formation of additional polymer,

neutralizing said additional catalyst, and separating said aromatic hydrocarbon material from the resulting reaction mass.

10. A process for refining aromatic hydrocarbon 46 material boiling below 400 C. and contaminated with polymerizable impurity of similar boiling point therewith, which comprises contacting said confiaminated "aromatic hydrocarbon material wit an acid-acting metallic halide catalyst un- 50 der conditionscausing the formation of polymer arating said fraction from the resulting reaction mass including said polymer, thereafter contact-' ing said fraction with a further quantity of from 0.5% to 5.0% by weight of said light oil fraction of aluminum chloride at a temperature in the from a portion of said impurity, neutralizing said catalyst, separating-said polymer and saidaromatic hydrocarbon material from the resulting reaction mass and from each other, thereafter iii! contacting said aromatic hydrocarbon material range of 0 C. to Cifor a period of at least one hour thereby causing the formation of oily polymer from the remaining polymerizable un- 00 polymer and said aromatic hydrocarbon material saturated hydrocarbonmaterial present, neutralizing said further quantity of aluminum chloride, and recovering toluene in more concentrated formfrcm the resulting reaction mass.

mauxasonar.

w t additional acid-acting metallic halide catalyst under conditions causing the formation of additional polymer neutralizing said additional catalyst. and'separating said additional from th'resulting reaction mass and from each other.