US2220092A

US2220092A - Conversion of hydrocarbon products

Info

Publication number: US2220092A
Application number: US176289A
Authority: US
Inventors: Bernard L Evering; George G Lamb
Original assignee: Standard Oil Co
Current assignee: Standard Oil Co
Priority date: 1937-11-24
Filing date: 1937-11-24
Publication date: 1940-11-05
Anticipated expiration: 1957-11-05

Description

Nov. 5, 1940. B. EVERING El AL 2,220,092

' CONVERSION OF HYDROGARBON PRODUCTS I Filed Nov. 24, 1937 2 Sheets-Sheet l I: scnusam Producf STAB/LIZER mncho/mrok mcuuumroa REACT ION ZONE 3nnentors George 6. Lamb Brnard L. Ever/71g (Ittomeg .sqrl/nnrzo 6/1555 FRQMOT Nov. 5, 1940'. s. EVERING ET AL 7 2,220,092

CONVERSION OF HYDROCARBON PRODUCTS Filed Nov. 24, 1937 2 Sheets-Sheet 2 u N e) N Y "2 A w a 3 a 3 0 4 W I {g q w a N z\ Q lmnentors GeorgeG. Lamb attorney Patented Nov. 5, 1940 UNITED STATES CONVERSION OF HYDROCARBON PRODUCTS Bernard L Evering and George G. Lamb, Chicago, 111., assignors to Standard Oil Company, Chicago, Ill., a corporation of Indiana Application November 24, 1937, Serial No. 176,289

8 Claims.

This invention relates to the preparation of saturated branched-chain hydrocarbons including the saturated iso-hydrocarbons from an admixture of higher-boiling and lower-boiling aliphatic hydrocarbons with the aid of catalysts.

- In particular, our invention relates to the preparation of motor fuel products containing large quantities of branched-chain saturated hydrocarbons.

Saturated branched-chain hydrocarbons, and particularly mixtures of them, are very useful as motor fuels on account of their antiknock properties and high heating value. Also, the saturated branched-chain hydrocarbons have lower boiling points than the corresponding straight-chain paraflins and, consequently, motor fuels containing substantial quantities of the former have better starting characteristics than motor fuels containing large quantities of the latter. In addition, branched-chain paraffin hydrocarbons, such as the iso-hydrocarbons, are very useful as starting materials in the preparation of many chemical products.

One of the principal objects of our invention is to convert an admixture of straight run naphtha, having a selected initial boiling point, and certain normally gaseous saturated hydrocarbons into branched-chain hydrocarbons having boiling points below or slightly overlapping the initial boiling point of the naphtha charged to the process. Examples of the parafiinic straight run naphthas are Mount Pleasant naphtha, Pennsylvania naphthas, Mid-Continent naphthas and the like. This conversion or branching of the hydrocarbons is effected without substantial formation of fixed gases such as hydrogen and methane. Following the conversion step the products are subjected, in one embodiment of our invention, to close fractionation in order to isolate a very substantial portion of the iso-and branchedchain paraffinic hydrocarbons. produced in the process. A further description of the fractionating step as adapted to our conversion process will be set forth in detail hereinafter.

Other objects, advantages and methods of utilizing our process will become apparent from the description hereinafter. In the drawings attached to and forming a part of the specification, Figure 1 is a diagrammatic illustration of one arrangement of the apparatus which may be used in practicing our process. Figure 2 is a diagrammatic illustration of the types of reaction zones which may be used in our process.

One embodiment of our process will be described with reference to'the conversion of saturated straight run petroleum naphtha having an initial boiling point above about 235 F. in the presence of an admixture of normally gaseous hydrocarbons such as propane, butane, and possibly some ethane. The straight run petroleum naphtha containing Ca and higher-boiling hydrocarbons, but substantially no hydrocarbons boiling below 235 F. enters the system through conduit A and is forced by pump 10 into the manifold II. A mixture of saturated gases containing propane, butane, and some ethane enters the system through line B and is forced by compressor l2 into the manifold II where they are mixed with the other products therein. Also, a

slurry or solution of aluminum chloride and light mineral oil is prepared in the catalyst mixer l3 and passed by pump I4 through line [5 to line I6 and then introduced into the manifold II. A promoter or activator, namely, hydrogen chloride, hydrogen bromide, carbon tetrachloride, the alkyl halides such as methyl chloride or bromide, ethyl chloride or bromide, propyl chloride or bromide, butyl chloride or bromide, or any compound which in the presence of an aluminum halide yields a hydrogen halide is added to the reaction zone l1 through conduit C with the aid of pump or compressor 29. Also, in the place of aluminum chloride we may use aluminum bromide. The naphtha, gases, catalyst and promoter are continuously fed to the system as above indicated and the admixture of materials is then passed through the elongated reaction zone or coil H which is maintained at a temperature within the range of 150-600 F., but preferably within the range of 200-500" F. or 300-475 F. The reaction zone may be modified as shown by Figure 2'. At

temperatures below about 475 F., substantially no fixed gases are produced during the conversion of the materials in zone l'l, however, at temperatures above about 475 F. a very small or negligible amounts of fixed gases may be formed. The pressure maintained in the coil or reaction zone l1 may vary over a wide range, that is, from atmospheric pressure to 6,000 pounds per square 1 inch. In some cases the pressure may be even higher. We prefer to use a pressure within the range of about 200-4,000 pounds per square inch. The time of contact employed in the reaction zone I! may vary'considerably, ranging from 1 to 150 minutes. When the naphtha in reaction zone I1 is mostly in the liquid phase, we may use a reaction time of from 1 to 120 minutes, but' preferably from 2 to 30 minutes. But when the hydrocarbon components, naphtha and feed gases, are reacted mostly in the vapor phase, the

reaction may be effected in a shorter period zone thoroughly mixed, the reaction time will be considerably reduced. By effecting the reaction chloride may be added to this aluminum chloridehydrocarbon-complex and the admixture used as the catalyst in the reaction zone l1.

The converted products pass'from the reaction zone through the transfer line 20 and valved conduit. 2| and are introducedinto the separator 22 where liquid phase separation is effected between the aluminum halide-hydrocarbon complex on the one hand and the reacted and'unreacted products on the other. Alternatively, the products in the transfer line may be passed through the cooler 23 before being introduced into the separator 22. The cooler is usually employed when the higher temperatures are used in the reactor H. To assist further inthe cooling of the products in the transfer line and thereby control the character of the reaction, all .or a part of the naphtha feed stock may be used as a quenching medium and introduced into the transfer line through valved conduit 24. Oils heavier than the feed stock may be used as the quenching medium and the quenching step may be used with or without the assistance of the cooler 23. When a part or all of the feed naphtha is intro- ,duced through line 24 and used as a quenching medium, it returns to the. reaction zone by the route of separator 22, line 38, accumulator tank 39 and line 40.

The aluminum chloride-hydrocarbon complex 49 settles to the lower part of the separator 22 in the form of a heavy liquid. This complex appears to be some kind of a loose combination between the aluminum chloride and a product of the aluminum chloride-hydrocarbon reactions. This 45 solution is withdrawn from the bottom of the separator 22 through line 25 and passed by pump 26 through line 21 and check valve 28 to conduit it 'where it is returned to the reactor to serve as the catalyst for effecting. the alteration of saturated straight-chain hydrocarbons into branched-chain parafiins or iso-hydrocarbons. When the aluminum chloride complex is recycled and used as the catalyst, hydrogen chloride or other hydrogen halides may be introduced into the system through line C and compressor 29 to serve as the promoter for the reaction. By recycling the aluminum chloride-hydrocarbon complex and adding small or large amounts of hydrogen chloride, as above described, only small amounts of the fresh catalyst need be added from time to time through line to make up for losses.- We have observed, however, that the presence of large amounts of hydrogen chloride in the reaction zone I! retards the formation of excessive amounts of aluminum chloride-hydrocarbon complex and thereby keeps the aluminum chloride in a highly reactive state for the purposes of our process. Intermittently or continuously all or a part of the aluminum chloride-hydrocarbon complex may be withdrawn through valved conduit 30 and discarded or revivified and re-used by introducing it into line l6. As another method of handling the aluminum chloride-hydrocarbon complex withdrawn from-the bottom of separator 22, it may be passed through line 25, pump 26 and valved conduit 30a to the catalyst mixer l3 where small amounts of aluminum chloride are added thereto. This admixture is then passed from the bottom of the catalyst mixer l3 and introduced into line l6'as hereinbefore described. If desired, small amounts of hydrogen halides such as hydrogen chloride and hydrogen bromide may be added to the catalyst in the catalyst mixer l3 by means of valved line l3a or introduced into the system through line C. In the operation of our process we prefer to add the promoter to the process iilgrough conduit C rather than through the mixer The reacted and unreacted hydrocarbon products in separator 22 which are above the liquid level of the aluminum chloride-hydrocarbon complex as shown by line 3| are withdrawn through line 32 with the assistance of pressure regulator 33 and introduced into the fractionator 34. The pressure regulator 33 effects the desired reduction in pressure on the products before they enter the fractionator 34.

Fractionator 34 may be operated at different temperatures and pressures, and it effects a sharp separation between the unreacted naphtha on the one hand and the saturated branched-chain or iso-hydrocarbons and added gases on the other. The hydrocarbon products withdrawn from the top of the fractionator 34 contain the added unreacted gases, branched-chain paraffinic hydrocarbons produced in the process and none or controlled amounts of the most volatile portion of the naphtha charged to the system. This overhead fraction from tower 34 is passed through line 35 to the cooler 36 and then introduced into the reflux efficient operation of our process. In one embodiment of our invention, the overhead products from tower 34 may consist almost entirely of the unreacted feed gases and a fraction of branchedchain saturated hydrocarbons boiling below the initial boiling point of the naphtha charged to the system. For example, if the feed gases are an admixture of saturated C2, C3 and C4 hydrocarbons and the feed naphtha has an initial boiling point within the range of 235 to 300 F., the overhead from tower 34 may consist almost entirely of unreacted feed gases and branched-chain saturated hydrocarbons boiling below the initial boiling point of the feed naphtha employed. Other naphthas used in our process may have initial boiling points ranging from 200 F. and higher. The feed gases may contain varying amounts of saturated C2, C3 and C4 hydrocarbons, for example, the feed gases may contain only the saturated C3 and C4 hydrocarbons.

In the second embodiment of our invention, the end boiling point of the fraction taken overhead from fractionator 34 may overlap to a certain extent the initial boiling point of the feed naphtha. In this embodiment, the branched-chain saturated hydrocarbons will be admixed with the hydrocarbons in the front end of the feed naphtha. It is not desirable to permit a large amount of the hydrocarbons in the most volatile portion of the feed naphtha to pass overhead from tower 34 because they tend to reduce the amount of branched-chain saturated hydrocarbons conlapping the initlal boiling point of the feed naphtha. For example, if the feed naph-tha has an initial boiling point of about 200 F 220 F., 235 F., or 265 F., the end boiling point of the overhead fraction from tower 34 may be above the initial boiling point of the naphtha used but below about 285 F. In most cases, the amount of branched-chain hydrocarbons in the overhead from tower 34 will be at least as high as 70% of the total parafiin'hydrocarbons boiling-above the C4 gases;

In general, when fractionator 34is operated so that the end boiling point of the overhead therefrom overlaps the initial boiling point of the feed naphtha, regardless of the initial boiling point of the feed naphtha, we prefer to fracti'onate to a degree defined by one of the following two metheds. The first method is to cut the end boiling point of the overhead from tower 34 at a point where the content of normally liquid straightchain paraffins therein (excluding the gases, namely those boiling below 55 F.) will not exceed about 4 to 7% by volume. The second method is to operate tower 34 so that the temperature of the 95% point of the overhead fraction shall not exceed the temperature of the 5% point of the fraction withdrawn from the bottom of tower 34. The 5% and 95% points mentioned above refer to an A. S. T. M. distillation curve. By following either of these methods for determining the degree of fractionation in tower 34, we may 40 recover a product from tower 50 which contains a very high percentage of saturated branchedchain hydrocarbons and which are very useful as high antiknock motor fuel per se or in combination with other gasoline fractions deficient in 45 high antiknock hydrocarbons.

Bubble trays 42 areplaced in the tower 34 to assist in the fractionation and it is desirable to use a large number of trays in order to effect the sharp fractionation between the products therein. A portion of the heavy productsin the bottom'of tower 34 are withdrawn from the trap-out plate 45, passed through line 45 to the reboiler 41 and then returned to the tower to supply heat for the fractionation of the products therein..

Aportion or all of the liquefied products in the bottom of reflux drum 31 are recycled through line 48 with the aid of pump 49 to the top ofthe bubble tower or fractionator 34 and used as reflux. The overhead from the reflux drum is introduced into the stabilizer 50 where the desired fractionation is made betweenthe normally'gase- -ous hydrocarbons on the one hand and the higher boiling products on the other.

. ing products consist mostly of the branchedchain' saturated hydrocarbons produced in the dition, a portion, or substantially all, of the C4 hydrocarbons in the stabilizer 50 may be removed fromthe bottom thereof along with the motor fuel fraction of branched-chain saturated hydro- 75 carbons. This is particularly desirable when the If, in carrying out this em- These higher boilprocess. In'some instances, depending upon the fractionation efie'cted in tower 34, controlled fraction of branched-chainhydrocarbons are to be blended with other hydrocarbon fractions such as. debutanized cracked gasoline, polymerized gasolines or any motor fuel deficient in light ends because the C4 hydrocarbons impart desirable volatility characteristics to" motor fuels. The

final product that is withdrawn from the bottom of stabilizer 50 through valved conduit 5| consists mostly of branched-chain paraflins, for example,

\ the branched-chain penta'nes, branched-chain hexanes, branched-chainheptanes and branchedchain octanes. From the foregoing description of our process it'is apparent that the product removed from the bottom of tower-50 through valved conduit 5| contains a very large amount of branched-chain saturated hydrocarbons and in addition, this fraction may be characterized asfollows: (a) having initial and endboiling points intermediate the gases and naphtha charged to the system; (27) containing C4 hydrocarbons such as butane and isobutane and having an end boiling point at or below the initial boiling point of the feed naphtha; (0) containing substantially no C4 hydrocarbons and having an end boiling point that overlaps to a small extent the initial boiling point of the feed naphtha; and (d) containing some C4 hydrocarbons and having an end boiling point that overlaps to a small extent the initial boiling point of the feed naphtha.

The unreacted gases, including all or controlled amounts of the C4 hydrocarbons, pass from the top of stabilizer through line 52 to condenser 53 and thence to the reflux drum 54. Bubble trays 55 or other fractionating means are placed in the stabilizer 50 to assist in the fractionation therein. A portion of the product in the bottom of the stabilizer may be withdrawn from trap-out plate 56 and .passed through line 5'! to the reboiler or heating means 58 and thence reintroduced into the tower. The heat added by the reboiler is sufficient to effect the desired fractionation in tower 50. It should be understood that other heating means may be used in the bottoms of

towers

34 and 50 instead of the herein described reboilers.

A portion of the liquid hydrocarbons in reflux drum 54, consisting almost entirely of saturated hydrocarbons, is withdrawn through line 59 and passed by' pump 60 through valved conduit 6| to the top of the stabilizer'for use'as reflux. A portion of this liquefied hydrocarbon product in line 59 may be passed through valved conduit 62 and introduced into the manifold H for further use in the process ofconverting straight-chain paraf- The uncondensed gases in reflux drum 54 may be recycled to the inlet side of the system through valved conduit 64. Gases in line 64 consist predominantly of-e'thane and propane and relatively small amounts ofbutanes. Also, the gases recycled through line 64 contain a portion of the hydrogen chloride gas or hydrogen halide gas that passed along with the overhead products. A portion or all of the hydrocarbons withdrawn from the top of-the reflux drum 54 maybe'passed through valved conduit 65 and introduced into the absorber 66 where the hydrogen chloride is separated from these gases. .Water, hydrochloric acid, or any other suitable solvent may be introduced into the top of the absorber through line 61 and withdrawn from the bottom thereof through line 68 with the dissolved hydrogen chlo- 5 ride. The thus washed gases may be vented through line 69 and disposed of in any suitable manner.

It is apparent, therefore, that in the operation of our process only the liquefied fraction of hydro- 10 carbons, consisting mostly of the butanes and propane withdrawn from the bottom of reflux drum 54, may be recycled through line 62 to the reaction zone. Alternatively, or in combination with this step, a portion or all of this liquefied l5 fraction and all or a substantial part of the gases removed from the top of the reflux drum 54 may be recycled to the reaction zone. As another modification, the liquefied fraction of hydrocarbons withdrawn from the bottom of the reflux 20 drum 54 and which is not used as reflux for stabilizer 50, may be withdrawn from the system through valved conduit 53; in this event, all or a substantial part of the hydrocarbons withdrawn from the top of the reflux drum are recycled to 25 the reaction zone.

In carrying out any of the hereinbefore described embodiments of our process, the pressure and temperature of the products in separator 54 may be regulated sothat the liquid product with- 30 drawn through line 63 will consist mostly ofbutanes. In this case, the liquid products withdrawn from the bottom of separator 54 are not recycled but all or substantially all of the gases removed from the top of the separator 54 are pre- 35 ferably recycled. The butanes separated through line 63 may be blended with other motor fuel fractions such as those hereinbefore described.

In another modification of our process, the feed gases introduced through line B may consist 45 largely of propane and butanes and the naphtha introduced through line A may have an initial boiling point above about 240 F. When these materials are used as a charging stock and subjected to the action of hydrogen chloride in the 45 presence of the aluminum chloride-hydrocarbon complex, the

fractionators

34 and 50 may be operated to give a product in line 5| which consists predominantly of branched-chain hydrocarbons containing 1 and 8 carbons atoms each. 50 Relatively smaller amounts of branched-chain hydrocarbons containing 6, 5 and 4 carbon atoms each will also be present in this product. The unreacted propane and butanes and the entrained hydrogen chloride will be recycled to the inlet side 55 of the system through lines 62 and/or 64.

The temperatures employed in the tops and bottoms of

towers

34 and 50 as well as the pressures maintained therein may be varied in order to effect the desired type of fractionation. When tower 34 is operated at a pressure of about 100 pounds per square inch, a top temperature of about 400 F, and a bottom temperature of about 580 F., the products removed from the bottom thereof through line 38 will consist mostly of C9 65 and higher vmolecular weight hydrocarbons whereas the products taken overhead from tower 34 will consist mostly of Ca and lower molecular weight hydrocarbons. When tower 50 is operated at a pressure of about 90 pounds per square inch,

70 a top temperature of about 140 F. and a bottom temperature of about 320 F., the products withdrawn through line will consist largely of branched-chain paraflins containing from C5 to Ca carbon atoms each in the molecular and the v75 hydrocarbons removed from the overhead of tower 50 will consist mostly of C4 and lighter hydrocarbons. The amount of hydrocarbons in the bottoms from tower 50 which are not branched-chain hydrocarbons will depend upon the degree of fractionation effected in tower 34. 5 In carrying out our herein described processes, the proportions of products charged to the reactor I! may vary somewhat, for example, for one part by weight of naphtha charged to the reactor, the parts by weight of hydrocarbon gases, aluminum 10 chloride and hydrogen halide may be from 0.1 to 1; 0.01 to 1; and 0.03 to 0.3 respectively. The proportions of ethane, propane and butanes in the feed gases may vary over a relatively wide 7 range. For example, the composition of the gases charged to reactor I! may contain from 15 to 40% by volume of ethane, 15 to 50% by volume of propane and 5 to by volume of butanes. It should be understood that other proportions of these hydrocarbons may be used in the feed gases. 20 In some cases, no ethane is charged to the system. The saturated hydrocarbon gases charged to the system may be derived from natural gas or separated from refinery gases. Methane does not assist in the reaction of producing branchedchain saturated hydrocarbons by our process and consequently should not be included in the feed gases. In any of the modifications hereinbefore set forth, we may withdraw a part of the oil from accumulator tank 39 through valved conduit 10 instead of recycling it to the reaction zone.

The fractions of branched-chain paramns produced by our process are particularly useful as aviation motor fuels. As stated hereinbefore, Figure 2 shows some of the modified forms of the reaction zone which may be used to effect intimate liquid phase contact as well as vapor phase contact between the hydrocarbon reactants and catalysts. In de- 40 scribing the three modifications of the reaction zone, the same numerals will be used, whenever possible, as are used on Figure 1.

Modification A illustrates the use of a mixer mounted within the reaction zone IT. This modification is used preferably for liquid phase operations. The feed naphtha, gases, catalyst and promoter enter the reactor I! through the manifold II and pass into the reactor through the line Ila. If desired, a part or all of the catalyst and/0r promoter may be added to the reactor through line llb. As the hydrocarbon, catalyst and promoter pass up through the reactor, they are thoroughly mixed by the revolving blades H which are mounted on the shaft 5 driven by the motor 12. A packing is placed around the shaft at I3 to prevent the escape of gases and liquids from the reaction zone. A closed steam coil 14 is placed inside the reactor to provide the necessary heat for the reaction, however, the products in line llmay be heated ,by any conventional means before entering the reactor ll. The converted products pass from the reaction zone through the transfer line 20,

valved conduit 2| and. are introduced into the a separator 22 where liquid phase separation is ef- 24. The aluminum halide-hydrocarbon complex is-withdrawn from the lower part of the sepa- ,rator 22 and passed by line 25, pump 26, line 21 and check valve 28 to the inlet of the reaction zone. Intermittently or continuously all or a part of the aluminum halide-hydrocarbon complex 5 may be withdrawn through valved conduit 30 and treated as hereinbefore described. The reacted and unreacted hydrocarbon products in separator 27.! which are above the liquid level of the complex as shown by line 3I are withdrawn through line 32 with the assistance of pressure regulator 33 and introduced into the fractionator 34. In brief, this modification of the reaction zone is very easily adapted to the process hereinbefore described with reference to Figure 1.

Modification C illustrates the use of a mixer mounted within the reaction zone, similar to that shown in modification A, with the improvement of permitting the recycling of gases within the reaction zone before the reacted and unreacted products are passed to the fractionating system. Th reacted products pass from the top of the reaction zone through line 20 and are introduced into separator 15 where the unreacted gases are withdrawn from the top thereof through valved conduit 16 and returned with the aid of the com. pressor 11 to the bottom of the reactor I1. This step of recycling the unreacted gases in combination with the turbo-mixer provides an excellent way of obtaining thorough contact between the gases and promoter on the one hand with the liquid feed naphtha and aluminum chloride catalyst on the other. The liquid products in the bottom of separator 15, including the aluminum halide-hydrocarbon complex as well as liquid hydrocarbon, are withdrawn from the bottom thereof through line I8 and introduced into the separator 22. The separation effected in separator 22 and the method of handling the aluminum halide-hydrocarbon complex and hydrocar- 40 bon products is the same as described with reference to modification A and also Figure 1. To prevent the building up of unreacted hydrocarbons within reaction zone I I, a valved by-pass 16a is provided for venting some of the gases in 5 separator I5 into conduit 32 so that they will pass into the fractionating system as described in Figure 1. v

In place of the mixer shown in the above two modifications, we may use a turbomlxer.

5o Modification B illustrates the use of a vapor phase reaction chamber. The feed naphtha, gases and promoter enter the reactor II through the manifold II and pass into the reactor through line IIb. If desired, a part or all of 5 the promoter may be added to the reactor through line Mb. The products in line IIa are sprayed or atomized into the bottom of the reaction zone -II. We prefer to heat the hydrocarbons in manifold II before they enter zone I! so that they will vaporize when introduced therein. A closed steam coil I4 is provided in the chamber to maintain the desired temperature therein. The catalyst comprising a mineral oil slurry of the aluminum halide is sprayed into the top of the chamber I! through conduit I5. This slurry of catalyst may be prepared in the mixer as shown by Figure 1. The countercurrent contact between the descending catalyst and ascending hydrocarbon vapors and promoter insures intimate contact between the products in the reaction zone II. The aluminum halide-hydrocarbon complex falls to the bottom of the chamber I1 and is withdrawn through line I9. If desired, the liquid level of the aluminum halide- 75 hydrocarbon complex or catalyst solution in zone II.may be permitted to rise a short distance above the level of the nozzle on line IIa so that the feed products in line II will be atomized into the liquid catalyst or catalyst slurry. This complex or liquid catalyst may be recycled directly to line I5 or it may be mixed with additional' quantities of the aluminum halide and/or promoter and returned to line I5. The reacted and unreacted hydrocarbon constituentsin zone H are withdrawn from the top thereof through line 80 with the assistance of the pressure-reducing valve 8| and introduced into the fractionator 34 as shown in Figure 1.

The pressure and temperature conditions maintained in modifications A, B and C of the reaction zone may be the same as those described in connection with Figure 1. Also, it has already been pointed out that the time of contact may vary over a relatively wide range and that thorough mixing or agitation of the constituents in reaction zone I! materially shortens this time of contact.

While we have described our invention with reference to specific examples by way of illustration, it is apparent that other modifications may be employed.

We claim:

1. In a process for converting substantial amounts of the straight-chain paraifin hydrocarbons in a low antiknock straight run petroleum naphtha into saturated branched-chain hydrocarbons whereby a motor fuel fraction having a relatively high antiknock value is obtained, the steps comprising contacting in a reaction zone an admixture of said petroleum naphtha, at least one normally gaseous hydrocarbon having at least two carbon atoms per molecule, a conversion catalyst selected from the group consisting of aluminum chloride, aluminum bromide and their hydrocarbon complexes, and a halogen-containing promoter for said catalyst, the reacting hydrocarbon gases present being largely heavier than methane and substantially free of unsaturated hydrocarbons, at an elevated temperature and pressure suflicient to convert a substantial part of the straight-chain parafiin hydrocarbons in said petroleum naphtha into saturated branched-chain hydrocarbons without substantial formation of hydrogen and methane, withdrawing the products from said reaction zone and separating said motor fuel fraction from said products.

2. In a process for converting substantial amounts of the straight-chain parafiin hydrocarbons in a low antiknock straight run petroleum naphtha into saturated branched-chain hydrocarbons whereby a motor fuel fraction having a relatively high antiknock value is obtained, the steps comprising contacting in a reaction zone an admixture of said petroleum naphtha, at least one normally gaseous hydrocarbon having at least three carbon atoms per molecule, aluminum chloride and a hydrogen halide, the reacting hydrocarbon gases present being largely heavier than ethane and substantially free of unsaturated hydrocarbons, at a temperature within the range from about 150 F. to about 600 F. and under superatmospheric pressure, whereby substantially no hydrogen and methane are formed, withdraw- 11 18 the products from said reaction zone and separating said motor fuel fraction from said products.

3. The process of claim 2 wherein said temperature is in the range from about 200 F. to about 500 F. and said pressure is in the range from about 200 to about 4000 pounds per square inch.

4. In a continuous process for converting substantial amounts of the straight-chain parafi'ln hydrocarbons in a low antiknock straight run petroleum naphtha into saturated branchedchain hydrocarbons whereby a motor fuel fraction having a relatively high antiknock value is obtained, the steps comprising contacting in a reaction zone an admixture of said petroleum naphtha, at least one normally gaseous hydrocarbon having at least three carbon atoms per molecule, a conversion catalyst selected from the group consisting of aluminum chloride, aluminum bromide and their hydrocarbon complexes, and a halogen-containing promoter for said catalyst, the reacting hydrocarbon gases present being largely heavier than ethane and substantially free of unsaturated hydrocarbons, at an elevated temperature and pressure sufficient to convert a substantial part of the straight-chain paraffin hydrocarbons in said petroleum naphtha into saturated branched-chain hydrocarbons without substantial formation of hydrogen and methane, withdrawing the products from said reaction zone and separating therefrom an aluminum halidehydrocarbon complex, fractionating the remaining hydrocarbon products to produce said motor fuel fraction and'a gaseous fraction consisting largely of hydrocarbons heavier than ethane and substantially free of unsaturated hydrocarbons, and recycling at least a portion of said gaseous fraction to said reaction zone.

5. In a continuous process for converting substantial amounts of the straight-chain parafiln hydrocarbons in a low antiknock straight run petroleum naphtha into saturated branched-chain hydrocarbons whereby a motor fuel fraction having a relatively high antiknock value is obtained, the steps comprising contacting in a reaction zone an admixture of said petroleum naphtha, at least one normally gaseous hydrocarbon having at least three carbon atoms per molecule, aluminum chloride and a hydrogen halide, the reacting hydrocarbon gases present being largely heavier than ethane and substantially free of unsaturated hydrocarbons, at a temperature within the range from about 150 F. to about 600 F. and under a pressure in the range from about 200 to about 4000 pounds per square inch, whereby substantially no hydrogen and methane are formed, withdrawing the products from said reaction zone and separating therefrom an aluminum chloridehydrocarbon complex, fractionating the remaining hydrocarbon products to produce said motor fuel fraction and a gaseous fraction consisting largely of hydrocarbons heavier than ethane and substantially free of unsaturated hydrocarbons, and recycling at least a portion of said gaseous fraction to said reaction zone.

6. In a process for producing a motor fuel-fraction rich in saturated branched-chain hydrocarbons and having a relatively high antiknock value, the steps comprising contacting in a reaction zone an admixture of a straight run petroleum fraction having an initial boiling point above about 200 F. and containing substantial amounts of straight-chain paramn hydrocarbons, at least one normally gaseous hydrocarbon having at least three carbon atoms per molecule, a conversion catalyst selected from the group consuiting of aluminum chloride, aluminum bromide it and their hydrocarbon complexes, and a hydrogen halide-afiording promoter for said catalyst, the reacting hydrocarbon gases present being largely heavier than ethane and substantially free of unsaturated hydrocarbons, at an elevated temperature and pressure sufflcient to convert a substantial part of the straight-chain paramn hydrocarbons in said petroleum fraction into saturated branched-chain hydrocarbons without substantial formation of hydrogen and methane, withdrawing the products from said reaction zone and separating said motor fuel fraction from .said products.

7. The method of producing saturated branched-chain hydrocarbons suitable as motor fuel of the gasoline type which comprises heating in a reaction zone a flowing stream of an admixture of straight r'un petroleum naphtha having an initial boiling point above about 200 F. and containing substantial amounts of straightchain paraffin hydrocarbons, substantially completely saturated normally gaseous hydrocarbons comprising mostly propane and butane, aluminum chloride and hydrogen chloride, at an elevated temperature and pressure suificient to convert a part of the saturated hydrocarbon components therein into saturated branched-chain hydrocarbons suitable as motor fuel and without substantial formation of hydrogen and methane, withdrawing the products fromthe reaction zone and separating an aluminum chloride-hydrocarbon complex therefrom, fractionating the remaining hydrocarbon products of conversion into an overhead fraction containing said saturated branched-chain hydrocarbons and a bottom fraction to such a degree that the temperature of the 95% point of the overhead fraction does not exceed the temperature of the point of the bottom fraction, and recycling at least a part of said bottom fraction to the reaction zone for further conversion.

8. In a process for producing a motor fuel fraction rich in saturated branched-chain hydrocarbons and having a relatively high antiknock value, the steps comprising contacting in a. reaction zone an admixture of a straight run petroleum fraction having an initial boiling point above about 200 F. and containing substantial amounts of straight-chain paraifn hydrocarbons, at least one normally gaseous hydrocarbon having at least three carbon atoms per molecule, a conversion catalyst selected from the group consisting of aluminum chloride, aluminum bromide and their hydrocarbon complexes, and a hydrogen halide-affording promoter for said catalyst, the reacting hydrocarbon gases present being largely heavier than ethane and substantially free of unsaturated hydrocarbons, at an elevated temperature within the range from about 150 F. to about 600 F. and under a pressure within the range from about 200 to about 4000 poundsper square inch, whereby a substantial part of the straight-chain parafiin hydrocarbons in said petroleum fraction is converted into saturated branched-chain hydrocarbons without substantial formation of hydrogen and methane, withdrawing the products from said reaction zone and separating said motor fuel fraction from said products.

BERNARD L. EVERING. GEORGE G. LAIVIB.