US2382445A

US2382445A - Cycloparaffin production

Info

Publication number: US2382445A
Application number: US538893A
Authority: US
Inventors: William E Ross; Pexxaglia Philip
Original assignee: Shell Development Co
Current assignee: Shell Development Co
Priority date: 1944-06-06
Filing date: 1944-06-06
Publication date: 1945-08-14
Anticipated expiration: 1962-08-14

Description

Au M 194 g 5 w. E. ROSS ET AL CYCLOPARAFFIN PRODUCTION Filed June 6, 1944 r. 8 mm mm .EXET: mm mm m W, a 1v B 8 in a Q 90.1% 2 @N Lu um mm .m 2

rL I Qv a r mm on X EPECBUEL 5 P M NWM uotmcorusm Inventor's: William E. Ross Philip Pzzmglia 51 fheir Afiorneq: Q2::

Patented Aug. 14, 1945 2,382,445 CYCLOPARAFFIN PRODUCTION William E. Ross, Oakland, and Philip Pezsaglia, Berkeley, Calif., assignors to Shell Development Company, San Francisco, Calif., acorporation of Delaware Application June 6, 1944, Serial No. 538,893 g 14 Claims.

This invention relates to an improved process for the separation of cycloparafllns from hydrocarbon mixtures comprising cycloparaflins in admixture with open chain parafllns. The invention relates more particularly to an improved process for the production of cycloparaflins of hydroaromatic structure from hydrocarbon mixtures of wide boiling range such as naphthenic gasolines comprising op n chain parafllns and available hydrocarbon mixtures are found therein in admixture with open chain paraflins. Realization of the full advantages inherent in the many chemical processes relying upon the cycloparaflins as starting or intermediate materials has heretofore been seriously handicapped by the lack of a process enabling the eflicient separation on a practical scale of the cycloparafiins from the open chain paraffins in admixture with which they are generally encountered. Thus, separation of the cycloparafiins from open chain paraffins having the same, or approximately the same, number of carbon atoms to the molecule by such -methods a fractional distillation, if at all possible, is often rendered so complex and delicate an operation as to render it impractical.

Of the cycloparaiilns, those of hydroaromatic structure are presently of' particular value and find application in the production of an exceedingly wide range of valuable organic products. The production of the cycloparaflins of hydroaromatic structure in a state of required purity is rendered even more difficult since, to the dimculty of their separation from open chain paraffins is added the often equally vexing problem of their separation from isomeric non-hydroaromatic cycloparafiins and other hydrocarbons of close boiling range or capable of forming azeotropes therewith. By the term "hydroaromatic cycloparafiins as used throughout this specification and appended claims is meant the cycloparaflins havin a h'examethylene ring such as, for example, cyclohexane and the alkyl cyclohexanes, to distinguish them from cycloparaflins of non-hydroaromatic structure comprising those having pentamethylene rings such as, for example, methylcyclopentane and the alkyl cyclopentanes.

It has been suggested heretofore to subject the hydrocarbon mixtures comprising open chain paraflins and cycloparaflins of non-hydroaromatic structure to isomerizing conditions effecting the conversion of non-hydroaromatic cycloparaffins to hydroaromatic cycloparafiins and thereafter subject the entire hydrocarbon mixture to fractionation to separate fractions comprising desired cycloparaflins. Although such a procedure enables the concentration on a practical scale of certain of thecycloparafilns such as, for example, cyclohexane, it still does not enable the attainment of desired yields in even such specific instances. Itfurthermore does not eliminate to a suflicient degree the'dimculties of separation. Thus, for example, in the production of cyclohexane from hydrocarbon mixtures comprising Co' parafllns and methylcyclopentane, the available raw material mustfirst be subjected to a fractionation resulting in the production of a methylcyclopentane concentrate. In so doing, a considerable amount of valuable cyclohexane originally present in the available raw material,

as well as a certain amount of methylcyclopentane, is left in the higher boiling fraction from which the methylcyclopentane concentrate is separated. Such methods furthermore offer limited advantages in only such specific cases. They do not provide a practical answer, for example, to the production of hydrocarbons predominating in methyl cyclohexane from the readily available hydrocarbon mixtures comprising the nonhydroaromatic cycloparafllns having seven carbon atoms to the molecule in admixture with close boiling open chain parafiins having seven and eight carbon atoms to-the molecule. In such case the problem of separation is in no wise overcome by isomerlzing the mixture as a whole under conditions resorted to heretofore.

In its broadest aspect. the object of the present invention is to provide an improved process enabling the more emcient separation of cycloparaffins from hydrocarbon mixtures comprising cycloparaflins and open chain paraflins.

A more particular object of the invention is the provision of a process enabling the more eflicient separation of cycloparaflins from hydrocarbon mixtures boiling in thegasoline boiling range and containing 'cycloparamns and open wide boiling range comprising methylcyclopentane.

Still another object of the invention is the provision of an improved process for the more efllcient production of methylcyclohexane from naphthenic hydrocarbon mixtures having a relatively wide boiling range and containing nonhydroaromatic cycloparamns having seven carbon atom to the molecule. Other objects and advantages of the invention will become apparent from the following description thereof.

It is known that unsaturated hydrocarbons such as olefins and aromatic hydrocarbons which react readily with aluminum chloride, are removed from hydrocarbon mixtures containing them by treatment with aluminum chloride. It has now been found that saturated hydrocarbons of cyclic structure comprising the cycloparafflns can be separated eiliciently by extraction under suitable conditions with a preformed complex obtained by the interaction of a metal halide of the Friedel-Crafts type and an organic compound. It has been found that by selection of suitable conditions the cycloparafllns of non-hydroaromatic structure present in the hydrocarbon mixture treated are converted to, and separately recovered, as cycloparaflins of hydroaromatic structure.

In accordance with the process of the invention, a hydrocarbon mixture of relatively wide boiling range comprising parafiins and cycloparaflins such as, for example, a naphthenic gasoline, is introduced into a feed fractionating zone. Within the feed fractionating zone there are separated a fraction of intermediate boiling range and a fraction or lower boiling range. The fraction of intermediate boiling range is passed into an extraction zone wherein it is contacted with a preformed organo-metal halide complex, obtained by the interaction of a. metal halide of the Friedel- Crafts type and an organic compound, under suitable conditions resulting in the formation of a rafllnate phase comprising paraflins and an extract phase comprising organo-metal halide complex and cycloparaflins. A suitable extraction zone comprises, for example, an enlarged chamber or packed tower containing suitable packing material through which the hydrocarbon charge is passed countercurrent to a descending stream of the organo-metal halide complex. The extract phase is passed into a scrubbing zone wherein it is scrubbed with a scrubbing medium comprising the lower boiling fraction separated in the feed fractionating zone. In passing through the scrubbing zone the cycloparaflins in the extract phase are separated from the organo-metal halide complex. The organo-metal complex is recycled from the scrubbing zone to the extraction zone. The hydrocarbon mixture eliminated from the scrubbing zone, comprising the lighter boiling fraction of the charge separated in the feed fractionating zone and the cycloparamns of intermediate boiling range, is passed into a fractionating zone. Within the fractionating zone the cycloparaflins of intermediate boiling range are separated as a. final product from the lower boiling scrubbing medium. The lower boiling sombbing medium is recycled, at least in part, from the iractionating zone to the scrubbing zone.

By maintaining suitable cycloparaflin isomerizing conditions within the extraction zone, comprising the introduction therein of hydrogen halide or a material affording a hydrogen halide, and the maintenance of temperature conditions defined more fully below, the isomerization of cycloparaflins such as, for example, the conversion of cycloparaillns of non-hydroaromatic structure to cycloparaflins of hydroaromatic structure is accomplished simultaneously with the extraction operation.

When the extraction zone is maintained under cycloparaflin isomerizing conditions the railinate phase eliminated therefrom comprising paraflins in the intermediate boiling range, and the hydrocarbon mixture comprising lighter boiling paraflins and cycloparafilns of intermediate boiling range removed from the scrubbing zone, are passed in separate streams to separate stripping zones wherein the hydrogen halide admixed therewith is separated as gaseous fractions. The gaseous fractions comprising the hydrogen halide promoter are recycled to the extraction zone.

It is to be noted that in the process of the invention a railinate phase comprising open chain paraflins, and an extract phase comprising organo-metal halide complex in admixture with cycloparaflins, are separately removed from the extraction zone, and'that such operation in no wise approximates the practice resorted to heretofore in the isomerization of hydrocarbons wherein hydrocarbons and catalyst are drawn in single stream from the reaction zone, and wherein hydrocarbons separated from catalyst drawn from the reaction zone are recombined with the total hydrocarbon efiluence from the reaction zone before or during product separation.

In order to set forth more clearly the nature of the invention it will be described herein in detail with reference to the attached drawing in which the single figure represents a more or less diagrammatic elevational view of one form of apparatus suitable for executing the process of the invention.

A hydr'ocarbon mixture of relatively wide boiling range comprising cycloparaflins and open chain parafiins such as, for'example, a naphthenic gasoline is forced by means of pump i through line 2 into -a feed fractionating zone. Suitable heating means such as, for example, a hydrocarbon fluid heater or indirect heat exchanger 3 is positioned in line 2. The feed fractionating zone is depicted in the drawing by a single fractionator 5 for the purpose of simplicity. It will be understood that in actual practice more than one such fractionator will generally be employed to eilect the desired feed fractionation. Within feed fractionator 5 there is separated a fraction of intermediate boiling range and a fraction of lower boiling range. The fraction of intermediate boiling range may suitably comprise hydrocarbons having six carbon atoms to the molecule, such as a hexane fraction comprising open chain hexanes, methylcyclopentane, and cyclohexane.

that the invention is in no wise limited to the separation of a hexane fraction as the fraction of intermediate boiling range. Thus, the intermediate boiling range fraction may comprise hydrocarbons having seven carbon atoms to the 6 molecule; a hydrocarbon mixture of wider boiling range comprising both Cs and C1 hydrocarbons, or a hydrocarbon mixture comprising or predominating in hydrocarbons having more than seven carbon atoms to theimolecule.

The hexane fraction is passed from fractionator 5 through line 6 into an extraction zone. The extraction zone may comprise an elongated chamber or column! containing inert solid contact material such as, for example Raschig rings, In

crushed brick, silica stone, etc. The hydrocarbon charge is introduced into the column at an intermediate point along the length thereof.

A preformed fluid organo-metal halide complex is introduced into the top of the column by means of a valved line 8. The fluid organo-metal halide complex is prepared by mixing a metal halide of the Friedel-Crafts type, for example, a halide of aluminum such as aluminum chloride and/or aluminum bromide with an organic compound under suitable conditions resulting in the interaction of the metal halide with the or-' ganic compound and/or decomposition products thereof. Suitable organic compounds with-which the metal halide may be combined underconditions resulting in the obtaining of a desired organo-metal halide complex comprising, for example, aromatic hydrocarbons such as benzene, toluene; hydrocarbon fractions such a an arothe intermediate fraction passed into extraction column I may suitably be separated in the feed fractionator 5 and passed therefrom to scrubbing column i5. Thus, instead of a pentane fraction, a butane fraction, or a fraction comprising both butane and pentane, may be passed from fractionator 5 to scrubber l5. Additional hydrocarbons lower'boiling than the fraction of intermediate boiling range passed into the extraction 0 column I, may be introduced into the system by the scrubbing column itself. Suitable temperatures to be maintained within scrubbing column I5 comprise a temperature in the range of, for example, from about 20 C. to about 140 C. and preferably from about 20 C. to about 80 C. The pressure within column. I5 is always kept sufiiciently high to maintain at least a substan tial part of the hydrocarbons passing therethrough in the liquid phase. Under these conditions aluminum chloride-hydrocarbon complex, free of any substantial amount of cycloparafl'ins, will settle in the lower part of scrubber l5 whence matic kerosene extract; cyclic olefins such as Slit is continuously withdrawn and forced through cyclohexane, cyclopentene, and alkyl derivatives thereof; parafiinic and oleflnic hydrocarbons of straight or branched chain structure; phenols; organic acids; ethers, etc. Of the suitable organo-metal halide complexes, those comprising the aluminum chloride-hydrocarbon complexare somewhat preferred.

By means of heat exchanger 9 and optionally heating or cooling means, such as closed coils l0, II and i2 within column ,I the hydrocarbons and complex are maintained in the temperature range of from about 20 C. to about 140 C., and preferably from about 20 C. to about 70 C. Atmospheric or superatmospheric pressures are maintained within column I. however, kept sufficiently high to maintain the hydrocarbons in the liquid phase. Under these conditions cycloparaiiins in the hydrocarbon mixture passing upward through the column will be selectively removed from open chain paraffins 5 resulting in the formation of a raffinate phase in the upper part of the column consisting essentially of paraffinic hydrocarbons, and an extract phase in the lower part of the column consisting essentially of complex and cycloparamns.

The extract phase comprising aluminum chloride-hydrocarbon complex and cycloparaflins is passed from the lower part of column I through valved line H into the upper part of a scrubbing zone. umn i5 provided with suitable packing material, baille plates, or the like.

The lower boiling fraction separated in feed fractionator 5 and comprising, for example, a

pentane fraction, is passed from fractionator 5 through line it into the lower part .of scrubber I5. Although a pentane fraction has been chosen as the fraction of lower boiling range passed from fractionator 5 to the scrubbing tower, any

suitable hydrocarbon fraction lower boiling than The pressure is, 60

The scrubbing zone may comprise a col- 65 line 2| into line 8 entering the top of extraction column 1. Hydrocarbons comprising pentanes, methylcyclopentane, and cyclohexane, free of any substantial amount of aluminum chloridehydrocarbon complex, are taken from the top of scrubber l5 and passed through line 23 containing cooler 24 into accumulator 25.

Liquid hydrocarbons are drawn from accumulator 25 and forced through

lines

26, 21 and 28 of pentane to extract phase is continuously passed through scrubber I5 to effect the substantially complete separation therein of the cycloparafiins from the aluminum chloride-hydrocarbon complex.

By thus scrubbing the cycloparaflins from the extract phase with a hydrocarbon fraction comprising hydrocarbons which are readily separable from the cycloparaflins contained in the extract phase, substantial advantages are obtained over such methods as separation by distillation. The use of scrubbing instead of distillation not only obviates the disadvantageous effect upon the useful life of the complex occasioned by continuous passage through a zone maintained at distillation temperatures, but greatly facilitates the flow of the complex through the system.

Cycloparaflins comprising methylcyclopentane and cyclohexane are passed from fractionator 29 The temperature within' through line 33 into a fractionator 35. Within fractionator 35 a vapor fraction comprising methylcyclopentane is separated from a liquid fraction comprising methylcyclohexane. The liquid fraction is eliminated from fractionator 35 through valved line 38 as a final product. The vapor fraction is eliminated from fractionator 35 through valved line 31 and at least a part thereof is recycled through line 38 into extraction column 1 and introduced therein at a point below the introduction of the hydrocarbon charge. This, it has been found, adds materially in the separation of cycloparaflins from paraflins under the operating conditions. A by-pass 39 is provided for the introduction of recycled methylcyclopentane into line 6.

The raffinate phase comprising open chain hexanes is taken overhead from column 1- and passed through line 40 into accumulator 42.

A particular advantage of the invention resides in the ability to recover the naphthenic hydrocarbons of non-hydroaromatic structure, originally present in the charge, in the form of naphthenic hydrocarbons of hydroaromatic structure.

Thus, in the treatment of a naphthenic hexane fraction containing methylcyclopentane, maintenance of suitable cycloparaflln isomerizing conditions within column fl enables the conversion of the methylcyclopentane to cyclohexane during the extraction operation. To attain these objectives of the invention, temperatures within column 'Iare maintained within the range of, for example, from about 30" C. to about 140 C. and preferably from about 70 C. to about 100 C. A

hydrogen halide promoter such as, for example,

hydrogen chloride or a material afiording the hydrogen halide under the conditions maintained in column I is introduced into the lower part of the column through valved line at a point below the introduction of the charge. A part of the hydrogen halide introduced into column I may be introduced directly into line 8 from line 48. The hydrogen halide promoter is introduced into the 'column at such a rate as to maintain a concentration of the hydrogen halide in the column in the range of from about 0.1% to about 2.0% and preferably from'about 0.1% to about 0.5% by,

Methyl pentane 4.5 Normal hexane 40.0

Mcthylcyclopentane 55.0 Undetermined 0.5

was contacted in a single stage operation with an aluminum chloride-hydrocarbon complex under the following conditions:

Ratio of complex to hydrocarbon 2:1 7 Time of contact minutes 30 Temperature CL- 70 Hydrogen chloride was bubbled through the liquid throughout the operation to maintain a concentration of HCl equal to 0.1% of the hydrocarbons charged. -A raflinate phase and an extract phase were separately withdrawn. The raflinate phase contained by volume of the hydrocarbons charged whereas the extract phase contained 30% of the hydrocarbons charged. A conversion of methylcyclopentane to cyclohexane of 40% was obtained. The degree of separation of cycloparaflins from open chain parafllns is exemplified by the following ratios of naphthenes to paraflins:

Ratio of naphthenes to parafllns in charge 1.25

Ratio of naphthenes to paraflins in raflinate 1.06

Ratio of naphthenes to parafllns in extract 1.6'2

Example II A methylcyclopentane concentration having the following composition:

' Percent volume Methyl pentane 4.0 Normal hexane 37.0 Methylcyc1ope'ntane- 51.0 Benzene 8.0

Ratio of complex to hydrocarbon 2:1 Time of contact minutes 30 Temperature 70 C.

Hydrogen chloride was bubbled through the liquid throughout the operation to maintain a concentration of HCl equal to 0.1% of hydrocarbons charged. A rafllnate phase and an extract phase were separately withdrawn. The rafiinate phasecontained 70% by volume of the hydrocarbons charged whereas the extract phase contained 30% of the hydrocarbons charged. A conversion of methylcyclopentane to cyclohexane of 35% was obtained. The separation of cycloparaffins from open chain parafllns is, exemplifled by the following ratios of naphthenes to Darafllns' Ratio of naphthenes to parafllns in charge- 1.24 Ratio of naphthenes to paraflins in raflinate- 0.84 Ratio of naphthenes to paraflins in extract- 1.64

during the execution of the process within the specified conditions.

When thus maintaining cycloparafiln isomerizing conditions within column 1, the railinate phase eliminated through line 40 as well as the Hydrocarbon mixture comprising pentane and cycloparafllns emanating from scrubber ii through line 23 will comprise hydrogen chloride.

The hydrocarbons comprising hydrogen chloride within accumulator 42 are forced through line 4! into a stripping column ll. ydrocarbons comprising pentaneand cycloparaflins and containing hydrogen chloride are taken from accumulator 25 and forced through line 26 into a separate stripping column 49. Within stripping

columns

48 and 49 conditions are maintained to eflect the removal of the hydrogen chloride from separated in columns, and is passed therefrom through lines 48, I and 6 into column I. Make-up HCl is introduced into the system by means of valved line 50.

Paramnic hydrocarbons comprising open chain hexanes are eliminated from the lower part of stripping column 48 as a final product. Hydrocarbons comprising pentane, cyclohexane and unconverted methylcyclohexane are passed from stripping column 49 through valved line 28 into fractionator 29.

In a further modification of the invention hydrogen halide, for example, hydrogen chloride, is introduced into the lower part of column it through valved line 60, but no hydrogen halid is introduced into column 1. Column 1 will then function as described above to efl'ect separation of cycloparaflins from paraffins in the absence of any substantial cycloparaflin isomerization, whereas in scrubber l5 isomerization of cycloparaffins, for example, conversion of cycloparaffins of non-hydroaromatic structure to cycloparafiins of hydroaromatic structure will take place. I

Available hydrocarbon mixtures comprising naphthenic hydrocarbons often contain, in addition to the open chain paraflins, a certain amount of aromatic hydrocarbons. Thus, the naphthenic hexane and/or heptane fractions will generally comprise a. certain amount of benzene and/or toluene. This material may be removed from the charge by suitable pretreatments prior to introduction into column I. The aluminum chloride-hydrocarbon complex, it has been found however, is far more selective as a solvent for aromatic hydrocarbons than for naphthem'c hydrocarbons. Distillation of the extract un'der conditions effecting the separation of cycloparafiins from the complex will generally result in a retention in the complex of at least a substantial amount of the aromatics originally present in the charge. In a modification oi the invention, when the charge tothe system comprises aromatic hydrocarbons, at least a part of-the complex eliminated from the, lowerpart of scrubber I5 is passed through line 5| containing heat exchanging means 52 into a second distillation zone comprising, for example, still 53. Within still 53 the complex, substantially free of cycloparafl'lns but still containing aromatic hydrocarbons, which in the treatment of naphthenic hexane fractions will comprise benzene, is, subjected to more drastic distillation conditions .to effect theseparation of substantially all of the benzene.' The more drastic conditions may be obtained by distillation at a higher temperature by means of heat input into heating means 52 and closed heating coil 54, by prolonged residence time inthe still, by use of subatmospheric pressure, by the introduction of stripping gases such' as hydrogen, methane, ethane, nitrogen, etc.,"through valved line 55 or HCl through line 59, or anytwo or more of these expedients. Vapors comprising benzene are eliminated from still 53 through valved line 56. Aluminum chloride-hydrocarbon complex, now free of any substantial amount of benzene, is passed from still 53 through valved line 51 and recycled at least in part through lines 58, 2| and 8 into the upper part of column 1.

The degree to which aromatic hydrocarbons can be separately recovered in the process of the Example In The complex remaining after separating the extracted cycloparafllns from the extract phase in the operation of Example 11 was subjected to distillation at a temperature of C., under a subatmospheric pressure of 150 mm. for a period of 2 hours. The resulting vapors were condensed and recovered. Upon analysis 33% by volume of the distillate was found to be aromatic hydrocarbon.

Example IV A hydrocarbon fraction boiling in the range of from 65 C. to C., containing normalhexane, methylcyclopentane, cyclohexane and 7% by weight of benzene was contacted countercurrently in continuous operation with an AlCla hydrocarbon complex thereby forming a paraf-- finic rafflnate phase and an extract phase containing the'complex, cycloparafllns and benzene. The extract phase was stripped at to 110 C., and atmospheric pressure for 30 minutes to remove cycloparafflns therefrom. The remaining complex was thereafter subjected to further stripping, with the aid of hydrogen chloride, at a temperature of 90 to C. for a period of one hour. Properties of the distillate product from the second stripping operation indicated it to contain above 90% of benzene.

The separate removal of the aromatics from the recycled complex is resorted to not only to maintain the efliciency of the aluminum chloride-hydrocarbon complex as the extracting medium and/or isomerization catalystfbut also to separately recover the aromatic hydrocarbons as a valuable by-product of the process.

The invention as described is capable of modifications without departing from the spirit and scope thereof. Thus, though a packed column has been chosen as a preferred extraction or extraction-isomerizing zone, other types of apparatus enabling intimate contact between th hydrocarbon charge and the organo-metal halide complex, resulting in the formation of an extract phase, and a rafllnate phase may suitably be used. Thus, column.'|'may suitably be replaced by a plurality of chambers connected in series provided with suitable stirring means through which the hydrocarbon fraction of intermediate boilin range is passed, and in which operation raflinate Igay be removed from one or more of the chamrs.

We claim as our invention:

1. The process for the production of-cyclohexane from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain hexanes and methylcyclopentane, which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction of intermediate boiling range comprising open chain hexanes and methylcyclopentane and a fraction of lower boiling range comprising pentane, subjectingv said fraction of intermediate boiling range and a hydrocarbon-aluminum chloride complex to continuous counter-current contact in the prescontacting zone, separately removing said extract invention is exemplified by the following example. 75 phase from the opposite end of said contactin zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said i'eed iractionating zone, thereby separating cycloparaflins from said complex in the scrubbing zone, passing hydrocarbons comprising cyclohexane, methylcyclopentane and said lower boiling hydrocarbons from said scrubbing zone into a product iractionating zone, and separating hydrocarbons comprising cyclohexane in said product iractionating zone.

2. The process for the production of cyclohexone from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain hexanes and methylcyclopentane which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction of intermediate boiling range comprising open chain hexanes and methylcyciopentane and a fraction of lower boiling range comprising pentane, sub- Jecting said fraction of intermediate boiling range and a hydrocarbon-aluminum halide complex to continuous counter-current contact in the presence of an added hydr en halide in a contacting zone at a temperature of from about 30 C. to about 140 C. to effect the conversion of methylcyclopentane to cyclohexane while forming a rafflnate phase comprising open chain hexanes and an extract phase comprising said complex, cyclohexane and unconverted methylcyclopentane, removing the raflinate phase from one end of said contacting zone, separately removing said extract phase from-the opposite end or said contabting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction oi lower boiling range separated in said feed iractionating zone, thereby separating cycloparaflins from said complex in the scrubbing zone, passing hydrocarbons comprising cyclohexane, methylcyclopentane and said lower boiling hydrocarbons from aromatic structure in said productiractionating zone.

4. The process for the production oi cycloparaffins of hydroaromatic structure from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain paraflins and cycloparai'iins of non-hydroaromatic structure which comprises,- iractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction 01' intermediate boiling range comprising open chain parafllns and cycloparaflins o1 non-hydroaromatic structure and airaction of lower boiling range, subjecting. said fraction 01 intermediate boiling range and an organo-aluminum halide complex to continuous countercurrent contact in the presence of an added hydrogen halide in a contacting zone at a temperature of from about C. to about 140 C. to eflect the conversion of cycloparaiiins o1 non-hydroaromatic structure to cycloparafllns of hydroaromatic structure while forming a rafllnate phase comprising open chain parafllns and an extract phase comprising said complex and cycloparafllns, removing the rafllnate phase from one end of said contacting zone, separately removing said extract phase from the opposite end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction oi. lower boiling range separated in said feed fractionating zone, thereby separating cycloparaflins from said complex in the scrubbing zone, passing hydrocarbons comprising cycloparaflins and said lower boiling hydrocarbons from said scrubbing zone into a product-tractionating zone, and separating hydrocarbons comsaid scrubbing zone into a product fractionating zone, and separating hydrocarbons comprising cyclohexane in said product fractionating zone.

3. The process for the production of cycloparafiins of hydroaromatic structure from a hydrocarbon mixture boiling in the gasoline boiling range comprising? open chain paraflins and cycloparaflins of non-hydrocaromatic structure which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction of intermediate boiling range comprising open chain paraflinsand cycloparafilns of nonhydroaromatic structure and a fraction of lower boiling range, subjecting said fraction of inter-- mediate boiling range and'a hydrocarbon-aluminum halide complex to continuous countercurrent contact in the presence of an added hydrogen halide in a contacting zone at a temperature of from about 70 C. to about 100 C. to effect the conversion of cycloparaflins of non-hydroaromatic structure to cycloparaflins of hydroaromatic structure while forming a raflinate phase comprising open chain paraffins and an extract lphase comprising said complex and cycloparafilns, removing the raflinate phase from one end of said contacting zone, separately removing said extract phase from the opposite end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said ieed iractionating zone, thereby separating cycloparafiins from said complex in the scrubbing zone, passing hydrocarbons comprising cycloparaflins and said lower boiling hydrocarbons from said scrubbing zone into a product fractionating zone, and separating hydrocarbons comprising cycloparaflins of hydroprising cycloparaflins of hydroaromatic structur in said product fractionating zone.

5. The process for the production of cycloparaflins of hydroaromatic structure from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain paraflins and cycloparaflins or non-hydroaromatic structure which comprises, iractionating said hydrocarbon mixture in a feed fractionating zone to separate a iraction of intermediate boiling range comprising open chain parafiins and cycloparafiins or nonhydroaromatic structure and a fraction 01' lower boiling range, subjecting said fraction of intermediate boiling range and an organo-metal halide complex to continuous countercurrent contact in the presence of an added promoter aflording a hydrogen halide in a contacting zone at a temp rature of from about 30 C. to about C. to effect the conversion of cycloparafiins of nonhydroaromatic structure to cycloparafiins of hydroaromatic structure while forming a rafllnate phase comprising. open chain paraflins and an extract phase comprising said complex and cycloparafiins, separately removing the ramnate phase and the extract phase from said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said feed fractionating zone thereby separating cycloparaifins from said complex, passing hydrocarbons comprising cycloparaflins and said lower boiling hydrocarbons from said scrubbing zone into a product separating zone, and separating hydrocarbons comprising cycloparafiins of hydroaromatic structure in said product fractionating zone.

6. The process for the production of cycloparailins of hydroaromatic structure from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain parafilns and cycloparaflins of non-hydroaromatic structure, which comprises, iractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction of intermediate boiling range comprising open chain paraflins andcycloparafiins'of nonhydroaromatic structure and a fraction of lower boiling range, subjecting said fraction of inter- 1 mediate boiling range and an organd-metal halide complex to continuous countercurrent contact in the presence of an added promoter affording a hydrogen halide in a contacting zone at cycloparaflln isomerizing conditions to eilect the conversion of cycloparafllns of non-hydroaromatic structure to cycloparafilns of hydroaromatic structure while forming a rafilnate phase comprising open chain 'parafilns and an extract phase comprising said complex and cycloparaflins, separately removing the rafllnate phase and the extract phase from said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said feed fractionating zone thereby separating cycloparafilns from said complex, passing hydrocarbons comprising cycloparaffins and said lower boiling hydrocarbons from said scrubbing zone into a product separating zone, separating hydrocarbonscomprising cycloparaiilns of hydroaromatic structure in said product fractionating zone, and recycling complex from said scrubbing zone to said contacting zone.

7. The process for theproduction of cyclohexane from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chainhexanes and methylcyclopentane which i comprises, fractionating said hydrocarbon mixture in a feed fractionatingzone to separate a fraction of intermediate boiling range comprising open chain hexanes and methylcyclopentane and a fraction of lower boiling range comprising pentane, subjectingsaid fraction of intermediate boiling range and a hydrocarbon-aluminum halide complex to continuous countercurrent contact in the presence of an added hydrogen halide I in a contacting zone at a temperature of from about 70 C. to--about 100 C. to effect the conversion of methylcyclopentane to cyclohexane while forming a raflinate phase comprising open chain hexanes and hydrogen halide and an extract phase comprising said complex, cyclohexane,

and an organo-metal halide complex to continuous countercurrent contact in th presence of an added promoter affording a hydrogen halide in a contacting zone at cycloparaflin isomerizing conditions to eflect the conversion of cycloparaflins of non-hydroaromatic structure to cycloparafiins of hydroaromatic structure while forming a ramnate phase comprising open chain parafflns and hydrogen halide and an extract phase comprising said complex, cycloparamns of hydroaromatic structure and hydrogen halide, passing said rafllnate phase into a stripping zone, passing said extract phase into a scrubbing zone, contacting said extract phase with said hydrocarbon fraction of lower boiling range separated in said feed fractionating zone, thereby separating cycloparaffins and hydrogen halide from complex in said scrubbing zone; passing hydrocarbons comprising cyseparating a gaseou fraction comprising hydrogen halide in each of said stripping zones, and recycling said gaseous fractions from said stripping zones to said contacting zone.

line boiling range comprising open chain hexanes,

methylcyclopentane and hydrogen halide, passing the raflinate phase from one end of said contacting zone into a stripping zone, passing said .extract phase from the opposite end of said contacting zone into a scrubbing zone, contacting said extract phase with said hydrocarbon fraction of lower boiling range separated in said feed fractionating; zone, thereby separating cycloparafiins and hydrogen halide from complex in said scrubbing zone, passing hydrocarbons comprising cycloparaflins and said lower boiling hydrocarbons in admixture with hydrogen halide from said scrubbing zone into a separate stripping zone, separating. a gaseous fraction comprising hydrogen halide inseach of said stripping zones, and recycling said gaseous fractions from said stripping zones to said contacting zone.

8.'-The process for the production of cyclopa afiins of'hydroaromatic structure from a hydrocarbon mixture in the gasoline boiling range comprising open chain parafiins and cycloparaflins of non-'hydroaromatic structure which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction-of in-,

termediateboiling range comprising open. chain paraflinsandcycloparaffin of non-hydroaromatic structure and a lower boiling fraction-subjecting said fraction of intermediate boiling range methylcyclopentane and benzene which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to separate a fraction of intermediate boiling range comprising open chain hexanes, methylcyclopentane and benzene and a fraction of lower boiling range comprising pen:

tane, subjecting said fraction of intermediate boiling range and a hydrocarbon-aluminum halide complex tocontinuous countercurrent contact in the presence of an added hydrogen halide in a contacting zone at a temperature of from about '70 C. to about C. to efiect the conversion of methylcyclopentaneto cyclohexane while forming a raflinate phase comprising open'chain hexanes and an extra phase comprising said complex, cyclohexane, methylcyclopentane and benzene, removing the raflinate phase from one end of the contacting zone, passing the extract scrubbing zone, passing hydrocarbons comprising said hydrocarbons of lower boiling range, cyclo-.

hexane and methylcyclopentane from said scrub bing zone into a product separating zone, separat ing hydrocarbons predominatin in cyclohexane in said product separating: fzone, passing "said residual fraction from said scrubbing zone'into a distillation zone, separating hydrocarbons prising benzene as ayaporffraction rromj'a liquid fraction comprising complexdn s aid distillation zone, and recycling said'lidui'd fraction from said distillation zone to the contacting zone;- I l 1 10. The process for the production of cycloparaflins of hydroaromatic'structure from a hy+- ing said mixture in a feed fractionating zone to separate a fraction of intermediate boiling. range comprising open chain paraflins, cycloparaflins of non-hydroaromatic structure and aromatic hydrocarbons and a fraction of lower boiling range, subjecting said fraction of intermediate boiling range and an organo-metal halide complex to continuous countercurrent contact in the presence of an added promoter afiording a hydrogen halide in a contacting zone at cycloparafllnisomerizing conditions to effect the conversion of cycloparafllns of non-hydroaromatic structure to cycloparafllns of hydroaromatic structure while forming a ratfinate phase comprising open chain parafllns and an extract phase comprising said complex, cycloparafllns and aromatic hydrocarbons, removing the raillnate phase from one end of said contacting zone, passing the extract phase from the opposite end of said contacting zone into a scrubbing zone, contacting said extract phase in the scrubbing zone with said hydrocarbon fract on of lower boiling range separated in said feed fractionating zone. thereby separating cycloparaillns of intermediate boiling range from a residual fraction comprising said complex containing aromatic hydrocarbons in said scrubbing zone, passing hydrocarbons comprising said hydrocarbons of lower boiling range and cycloparafiins of intermediate boiling range from said scrubbing zone into a product separating zone. separating hydrocarbons predominating in cycloparailins of hydroaromatic structure in said product separating zone, passing said residual fraction from said scrubbing zone into a distillation zone, separating hydrocarbons comprising aromatic hydrocarbons as a vapor fraction from a liquid fraction comprising complex in said distillation zone, and recycling said liquid fraction from said distillation zone to the contacting zone.

11. The process for the production of cycloparafllns from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain paraillns and cycloparaillns which comprises, iractionating said hydrocarbon mixture in a feed fractionating zone to eiIect the separation of a fraction of intermediate boiling range comprising open chain paraflins and cycloparaflins, and a fraction of lower boiling range, subjecting said traction of intermediate boiling range and a hydrocarbon-aluminum chloride complex to continuous countercurrent contact at a temperature of from 20 C. to about 70 C. in a contacting zone to form a raillnate phase comprising open chain paraflins and an extract phase comprising said complex and cycloparafllns, removing the rafflnate phase from-one end of said contacting zone, separately removing said extract phase from the opposite end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said feed fractionating zone' thereby separating cycloparafllns of intermediate boiling range from said complex, passing hydrocarbons comprising said hydrocarbons of lower boiling range and cycloparafllns of intermediate boiling range from said scrubbing zone into a product separating zone, and separating hydrocarbons predominating in cycloparafllns of intermediate boiling range in said product separating zone.

12. The process for the production of cyclopar'aflins from a hydrocarbon mixture boiling in the gasoline boiling range comprising open chain paraflins and cycloparaflins, which comprises lractionating said hydrocarbon mixture in a feed fractionating zone to efiect the separation of a fraction of intermediate boiling range comprising open chain parafllns and cycloparafllns and a fraction of intermediate boiling range and an organo-aluminum halide complex to continuous countercurrent contact at a temperature of from 20 C. to about C. in a contacting zone to form a raflinate phase comprising open chain parafllns and an extract phase comprising said complex and cycloparafiins, removing the raflinate phase from one end of said contacting zone, separately removing said extract phase from the opposite end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction or lower boiling range separated in said teed fractionating zone thereby separating cycloparafilns of intermediate boiling range from said complex, passing hydrocarbons comprising said hydrocarbons of lower boiling range and cycloparaflins of intermediate boiling range from said scrubbing zone into a product separating zone, and separating hydrocarbons predominating in cycloparaflins of intermediate boiling range in said product separating zone.

13. The process for the production of cycloparaillns from a hydrocarbon mixture boilin in the gasoline boiling range comprising open chain parafiins and cycloparaiiins, which comprises fractionating said hydrocarbon mixture in a feed fractionating zone to effect the separation of a fraction of intermediate boiling range comprising open chain paraflins and cycloparafiins and a traction of lower boiling range, subjecting said fraction of intermediate boiling range and an organo-metal halide complex to continuous countercurrent contact at a temperature of from 20 C. to about 140 C. in a contacting zone to form a raflinate phase comprising open chain paraflins and an extract phase comprising said complex and cycloparamns, removing the raifinate phase from one end of said contacting zone, separately removing said extract phase from the opposite end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said feed fractionating zone thereby separating cycloparaflins of intermediate boiling range from said comp1ex,'passing hydrocarbons comprising said hydrocarbons of lower boiling range and cycloparaflins of intermediate boiling range from said scrubbing zone into a product separating zone, and separating hydrocarbons predominating in cycloparaflins of intermediate boiling range in said product separating zone.

14. The process for the production of cycloparailins from a hydrocarbon mixture boiling in the gasoline boiling range comprising cycloparafllns in admixture with open chain parafllns and aromatic hydrocarbons which comprises, fractionating said hydrocarbon mixture in a feed fractionating zone to efiect the separation of a fraction of intermediate boiling range comprising open chain paraflins, cycloparaflins and aromatic hydrocarbons and a fraction of lower boiling range, subjecting said fraction of intermediate boiling range and an organo-m'etal halide complex to continuous countercurrent contact at a temperature of from about 20 C. to about 140 C. in a contacting zone to form a raflinate phase comprising open chain paraffins and an extract phase comprising said complex, cycloparaflins and aromatic hydrocarbons, removing the raflinate phase from one end of said contactin zone, removing the extract phase from the other end of said contacting zone, contacting said extract phase in a scrubbing zone with said hydrocarbon fraction of lower boiling range separated in said feed frac- Iraction of lower boiling range, subjecting said (5 tionating zone, thereby separating cyclo of intermediate boiling range from a residual zone, passing said residual fraction from said scrubbing zone into a distillation zone, separating hydrocarbons comprising aromatic hydrocarbons as a vapor fraction from a liquid fraction comprising complex in said distillation zone, and recycling said liquid fraction from said distillation zone to the contacting zone.

WILLIAM E. ROSS. PHILIP PEZZAGHA.