US2321914A - Refining process - Google Patents

Description

June 15, 1943. A. P. HEWLETT EF'AL 2,321,914

HEFINING PROCESS I Filed May 27, 1939 Patented June 15, 1943 REFINING PROCESS Amiot P. Hewlett, Summit, and Gerald E. Phillips, Craniord, N. .I., asslgnors to Standard Oil Development Company, a corporation oi Delaware Application May 27, 1939, Serial No. 276,080

'3 Claims. (Cl. 196-96 The present invention relates to an improved process comprising a particular sequence of stages by which it is possible to produce high quality gasolines not heretofore secured by processes known in the art. The process of the present invention comprises cracking selected feed stocks under restricted vapor phase temperature and .pressure conditions, passing the resulting vapors through bauxite and then through clay. If the feed oil comprises high sulfur stocks, respective fractions after bauxite and clay treat are segregated, acid treated and further refined in an optimum manner.

It is well known in the art to subject various petroleum oil feed stocks such as gasolines, gas

oils, reduced crudes and the like to temperature and pressure conditions to form relatively lower boiling materials and relatively higher boiling materials. It is also known in the art to refine the resulting products by treatment with acid, clay, bauxite, and the like. The art of segregating the resulting product into various fractions in order to secure more efiicient and eco-- nomical refining operations is also known. The

results secured seemed to be more or less additive and the assumption had been to a large extent that no interrelationship existed between the successive refining steps. For example, it had been assumed that one type of cracking operation could be readily substituted for another and that equivalent results would be secured in the subsequent refining of the petroleum stock.

However, we have now discovered that providing a certain sequence of carefully controlled stages be employed in the treatment of particular feed stocks, unexpected, desirable results are secured which could not be foreseen from disclosures in the art. We have discovered that if feed stocks are segregated into relatively high and into relatively low.sulfur feed stocks and that if these feed stocks are then subjected to restricted vapor phase cracking conditions, an apparent chemical arrangement of the molecules occurs which seemingly renders the feed stocks susceptible to further rearrangement by subsequent treatment with bauxite, clay and acid in a manner to produce a high quality high octane number gasoline product. Apparently the vapor phase gasoline produced under the particular vapor phase cracking conditions employed is susceptible to iso'merism and perhaps scission by subsequent treatment with bauxite and clay which results in a high quality gasoline,

The process of our invention may be readily understood by reference to the diagrammatical For purposes of illustration, the vapor is assumed to be a high sulfur gas oil. is introduced into the lower part of primary tower l by means of fresh feed line 2. The fresh feed, togther with cycle oil, is withdrawn from the bottom of primary tower I by means of line 3 and is introduced into heatingcoil t, in which the temperature is raised the desired extent. In general, when operating as described, the oil is heated in coil 4 to a temperature somewhat below cracking temperatures. Under certain conditions it may be desirable to introduce a portion or the entire quantity of fresh feed directly into heating coil 4 by means of line 5. The heated oil is withdrawn from heating coil 4 by means of line 6 and introduced into drum 1. In drum l substantially the entire quantity of oil is vaporized and separated from a relatively small per cent of unvaporized material. The unvaporized material is removed from drum l by means of line 8 as a residue. This residue may be recycled, if desired, or may be discarded from the system. The vaporized oil is removed from drum '5 by means of line 9 and introduced into a secondary heating coil H0, in which'the temperature is raised to cracking conditions. The heated oil is withdrawn from heating coil It by means of line H and introduced into soaking drum or reaction chamber ii, in which the oil is held under cracking conditions for a suificient length of time to produce optimum conversion of the feed. A downflow soaking drum operation is illustrated, but it is to be understood that either a downflow or an upfiow operation may be employed. The products are withdrawn from reaction drum H by means of line 53 and passed through a pressure release valve id. The products under reduced pressure are released into evaporator or tar settler i5. Tar of the desired gravity, usually from 8 A. P. I. to 12 A. P. 1., may be withdrawn from evaporator it by means of line it. The vapors pass overhead from evaporator it through vapor line ll into primary tower i. Cycle stock accumulates in the bottom of primary tower i and vapors pass overhead through vapor line it into secondary tower It. The temperature at the top of primary tower i is so adjusted as to secure the desired endpoint Y in the products withdrawn from the bottom of secondary tower IS. The temperature at the top of secondary tower i9 is controlled so as to line 2! The vaporous overhead product from second ry tower is is preferably heated to the desire extent in heater 22 and then introduced by means of line 23 into bauxite treat 24. The oil is then withdrawn from bauxite treat 24 by means of line 25 and cooled in cooler 28. It is to be understood that cooler 28 may comprise a water cooler or a suitable heat exchanger, as for example, a feed oil to vapor heat exchanger. The cooled vapors are withdrawn from cooler 20 and introduced into clay treater 21. The bauxite and clay treated oil is then introduced into fractionating tower 28 by means of line 20. The temperatures and pressures maintained on tower 28 are adjusted to remove overhead by means of vapor line 30 hydrogen sulfide and gases boiling in the methane and ethane boiling range. The bottoms are withdrawn from tower 28 by means of line 3| and introduced into fractionating tower 32. The temperatures and pressures maintained on tower 32 are adjusted to remove overhead by means. of vapor line 33 gases boiling in the propane and butane boiling range. These gases are preferably processed in a suitable polymerization plant and blended back with a finished gasoline in order to increase the yield of high octane number gasoline,

The bottoms from tower 32 are introduced into distillation unit 34 by means of line 35. A relatively lower boiling fraction is removed overhead by means of line 36, while a relatively higher boiling fraction is removed as bottoms by means of line 31. The relatively higher boiling fraction is acid treated in treating unit 88 with acid introduced by means of line 39. The acid sludge is removed from treating unit 38 by means of line 40. The acid treated oil is removed by means of line 4!, soda washed in treating unit 42 and then introduced into distillation unit 48 by means of line 44. A residue is removed from distillation unit 43 by means of line 45, while the treated stable distillate is removed overhead by means of line 46 and combined with the lower boiling distillate removed overhead from distillation unit 34 bymeans -of line 36.

It is to be understood that the operating procedure may be varied considerably within the scope of the present invention. For example, although it is preferred to employ two heating coils in series and to remove a residue prior to heating the oil to cracking conditions in the secondary coil, it is to be understood that under certain conditions a single heating coil may be employed. Under these conditions the oil would be heated to cracking temperatures in heating coil 4 and then introduced directly into reaction chamber l2 by means of line 41. Under certain conditions it may be desirable to employ a coil only operation, in which case the oil would be heated to cracking conditions in heating coil 4 and introduced directly into. separator I! by means of line 48. Valves 48, 80, II, 42, and I4 could be readily adjusted to secure the desired operation. vWhen operating in accordance with the preferred modification, the oil is preferably heated in heating coil 4 so that substantially complete vaporization will be secured in drum I. The amount of residue withdrawn from drum 1 should be in the range from 1% to In general, it is preferred to bauxite treat only those gasoline fractions boiling in the gasoline range,

as for example, those fractions having a boiling point below about 420 F. These fractions are removed overhead from the secondary tower and are preferably heated and then passed through the bauxite. However, under certain conditions it may be desirable to condense the overhead removed from tower II by means of line 51 and introduced into a subsequent fractionating tower 88. Temperature and pressure conditions are maintained on tower 58 in order to remove overhead by means of line 08 gases boiling in the propane and butane ranges. These gases are preferably processed in a suitable polymerization plant and blended back with a finished gasoline in order to increase the yield of desirable high octane number gasolines. Bottoms are removed from tower 08 by means of line 50 and passed through heater 22'. This operation could readily be secured by adjusting valves 8!, 82, and 88. In general, the oil is clay treated after being bauxite treated. It is to be understood, however,

that under certain conditions, particularly if the Y oil has a satisfactory octane number, color and gum stability, it may bypass the clay treat by means of lines 84 and 66. If the feed oil comprises a low sulfur gas oil, as for example, a gas oil from East Texas crude, the product may be withdrawn by means of line 65. These operations may be secured by adjusting valves 81, 68, 60, ill, and H. However, in general, it has been found that the preferred operation is to clay treat the bauxite treated oil, in which case low sulfur products would be withdrawn by means of line 12. It is to be understood that any suitable pumping means and the like may be employed, as well as any heat exchanging equipment, to secure a desired optimum operation.

When treating vapor phase distillates with sulfuric acid it has been found that the acid sludge separates with great diillculty and is extremely viscous and difficult to remove from the treating equipment. In addition to this, such acid treated distillates when passing through the customary water washing and neutralization stages form very stable emulsions with the result that considerable loss is encountered due to this emulsion formation. When bauxite and clay treating prior to acid treating, this dimculty is entirely avoided. The sludge produced separates very readily from the distillate and is extremely fluid in nature and is light in color. Furthermore, the acid treated distillate on being water washed and neutralized with caustic forms no emulsion and considerable saving is thus secured. The treating losses shown by the data presented do not take into account emulsion losses, but are merely losses which occur as sludge loss and polymer loss. In actual operation, however, when acid treating vapor phase cracked stock in the conventional manner, a considerably lower yield of product would be obtained due to emulsion losses which have not been taken into account.

The conditions of the present invention must be carefully controlled and a particular sequence of stages employed. The feed oils which are subjected to vapor phase cracking conditions may be any suitable petroleum oil. However. preferred oils are heavy naphthas and petroleum gas oils boiling in the ransefrom about 400 1''. to 900 F. These oils are preferably segregated into relatively high and into relatively low boilin oils. Relatively low boiling oils are those oils having at least 90% distilled at 700 F., Engler, while relatively high boiling oils are those oils having about 90% distilled at 900 F. The feed oils are also segregated into relatively high and into relatively low sulfur stocks. Relatively low sulfur feed stocks are feed oils from which vapor phase cracked distillates containing less than about 0.3% sulfur are produced, while relatively high sulfur feed stocks are feed oils from which vapor phase cracked distillates containing from about 0.3% to 1.0% are produced.

The particular vapor phase cracking conditions employed will be varied somewhat with respect to the character of the petroleum oil being processed. However, in general, the oils are subjected in the vapor phase to pressures in the range from about atmospheric to 250 pounds gage pressure, preferably to pressures less than about 200 pounds gage. The oil cracking temperatures employed are in the range from about 970 F. to

1400 F., preferably in the range from about 1000 F. to 1200 F. If the feed oil is a relatively low boiling oil, desirable vapor phase cracking results are secured by cracking at an oil temperature in the range from about 970 F. to 1000 F. and at a pressure in the range from about 150 pounds to 200 pounds gage. However, if the feed oil comprises a relatively high boilingoil, preferred oil temperatures are in the range above about 1150 F. and preferred pressures in the range below about 60 pounds gage.

The products removed from the cracking coil are passed in the vaporous state through a bed of bauxite at a temperature in the range from about 600 F. to 850 F. It has been found that temperatures in the range from about 800 F. to 850 F. are especially desirable. Under certain conditions it may be desirable to entirely con dense the distillate and to separate the uncondensed gases therefrom. The separated gases may be burned, but are preferably treated in a polymerization plant to further increase the yields of high quality, high octane number gasoline. Feed rates through the bauxite will vary and, to a large extent, will depend upon the particular petroleum oil being treated. However, in general, we have found that a feed rate of one liquid volume per volume of catalyst per hour will give desirable results. The bauxite treated material is then cooled and passed through clay at a temperature in the range from about 340 F. to 600 F., preferably at a temperature of 400 F. to 500 F. Attapulgus clay is preferably used, although other clays such as acid treated clays are also satisfactory. Gases may be separated from the bauxite and clay treated distillate by pounds to 25 pounds of 98% acid per barrel of oil or its equivalent. The acid treated oil after removal of the acid sludge is then washed with suiflcient soda in order to neutralize the acidic constituents remaining in the oil. The acid soda treated oil is then rerun under onditions in which about 95% to 98% is removed overhead I and blended with the bypassed distillate.

In order to further illustrate the present invention, the following examplesare given which hould not be construed as limiting the invention in any manner whatsoever:

EXAMPLE 1 TABLE 1 Before After bauxite bauxite and clay and clay treatment treatment Percent Per em Aromatics 6 c 5 Straight chain olefins. 37 42 Branched olefins. 4 l0 Unsaturated naphthen 41 30 Saturated naphthenes.. J6 Straight chain paraffins 5. 5 12 5 l3 Branched chain paraifins 0. 5 [2 The above data indicate that isomerism and some scission seem to be essential reactions tak- 'ing place and are apparently the explanation for the high octane number improvement which results from bauxite and clay treatment of these particular stocks. substantial change occurred with respect to the amountof saturated naphthenes and saturated paraiiins present.

EXAMPLE 2 Gas oils from East Texas crudes were cracked under various conditions to secure petroleum fractions boiling within the gasoline range. The

passing the treated distillate into a separation drum. The separated gases may be burned, but are preferably passed through a suitable polymerization plant to further increase the yield of The undistilled bottoms are acid treated with an optimum amount of acid which will depend upon the properties of the oil being treated. In general, it has been found that desirable results are secured by treating the oil with from about 20 cracked naphthas from the respective processes were then subjected to a bauxite and clay treat. The results of these operations were as follows:

TABLE 2 NAPTHA BEFORE BAUXI'IE AND CLAY TREAT Secured from East Texas gas oil (vapor phase cracking) Secured from East Texas gas oil (high pressure cracking Secured from East Texas gas oil (low pressure cracking Cracked at pounds/sq. in gage"... pounds" l, 000 200 Temperature 900-925 900-925 1050 It should be noted that no 4 INSPECTIONS F FEED NAPHTHAS T0 BAUXITE AND CLAY TREAT Suliur ..per cent.. 0.096 0.056 0.040 Octane No. Clear (A. S. T. M. 64. 7 64.6 66.0

Octane No. with 1% cc. tetraethyl lesd(A.S.T.M.) 72.0 71.7 73.0 Octane No. with he tetraethyi lead (A. 8. T. M.) 75. 2 74.7 78.6 Grsvit A.P.il.... ..s.... 61.1 01.1 56.6 Percentdistllled at 212 F. Engler. 33. 0 32. 0 34. 0

NAPHIHA AFTER BAUXITE AND CLAY TREAT duliur iper cent. 0. 059 0.031 0. 027 Octane No. Clear (A. S. 67.1 60. 4 76. l Octane No. with 13600. tetrsethyi Iead(A. S. T. M. 75.5 78.2 80.3 Octane No. with 30c. tetraethyl lead (A. S. T. M.) 78. 9 80.4 86.3 Gravity A. P. I 00. 9 61. i 57. 3 Percent distilled at 212 F. Englen. 31.5 31.0 35.0

OCKANE NUMBER IlgOXEAS E DUE TO BAUXIIE AND L Y TREAT Octane No. Clear (A. S. T. M.)... 2. 4 4.8 0. 5 Octane No. with 1 tetraethyl lead (A. S. T. M. 3. 5 6. 5 7.3 Octane No with 300. tetraethyl lead (A. 8. T. M.) 3.7 5.7 7.7

A. 8. T. M. octane number determination: Described in the Committee D-2 Report oi A. S. T. M. Standards on Petroleum Products and Lubricants, A. S. T. M. designation D-357-38T.

1 vglllume oi tetra ethyl lead as given in tables is cubic centimeters per g on.

The above data clearly illustrate the fact that the bauxite and clay treat is far more efl'ective in the treatment or the vapor phase cracked stock then. in the treatment of oils cracked in the liquid phase.

EXAMPLE 3 A high sulfur gas oil was cracked at a high pressure and a similar sample was cracked in the vapor phase at a temperature of about 1050 F. and at about 60 pounds pressure. Portions of the respective stocks were acid treated, while other portions were treated with bauxite, clay and then acid. The results 01 these finishing operations may be summarized as follows:

. Tsar: 3

Finishing high sulfur cracked distillates produced by vapor phase cracking and by high pressure cracking respectively, by combination with bait-rite, clay and acid treating From the above data it may be seen that the sludge loss was considerably decreased when treating the vapor phase gasoline with bauxite, clay. and acid. over the use of acid alone. It may also be seen that the sludge 1055 was not mate- Final boiling point, Engier '.F..

distillate with bauxite, clay, and acid, over acid treatment alone.

EXAIIPLE A large crude having a gravity of 16 to 17 A. P. I. and a suliur determination of 2.35 was distilled in a manner to remove about 7% naphtha and to recover about 37% gas oil having a gravity oi about 26 A. P. I. The inspection of the gas oil was as follows:

Test: 4

Initial boiling point F 391 distilled at F 697 Aniline point 138 Sulfur determination --per cent 1.23

Respective portions oi! the gas oil were cracked under the following conditions:

TABLE 5 Opera- Operation A tion B Coil outlet temperature 1020 1036 Pressure pounds/sq. in. gage 60 00 Conversion per pass 10.9 13.6 400 F. end point yleld. ...volume per cent.. 48.3 49. 5 Final tar ..do.... 32. 4 31. 2 as ..weight per cent. 21. 1 21. 1

l Butane and lighter.

as follows:

TABLE 6.

o Opera- Opera- Inspection-400 F. and point gasoline on A on B Y Gravity A. P. I 52.7 51. 2 Aniline Point 43 40 Reid vapor pressure ..pounds/sq. in. 11. i 10.9 Suliur determination per cent.. 0. 286 0.322 Octane No. (A. S. T. M.) 74. 8 75.0 1X00. tetraethyi lead (A. S. T. M 77.1 76. 6 Kim. tetraethyl lead (A. B. T. M.) 78.1 78. 1 Initial boiiin point, Engler F .84 83 Percent disti led at 212 F., Engler.... 34. 5 34. 0 Percent distilled at 257 F., Engler. 48. 5 47. 6 Percent distilled at 356 F., Engier. 86. 0 82. 0 405 415 Approximately 49.2% of the gasoline produced by operation A was combined with about 50.8%

' oi the gasoline produced by operation B. The

inspections oi the blended gasoline were as toiows:

'Issu: 7 Inspection- Gravity A. P. I 51.9 Sulfur determination, per cent 0.338 Octane No. (A. B. T. M.) 74.9 clear 1% cc. tetraethyi lead (A. T.

T. M.) 72.8 3 cc. tetraethyl lead 78.1 I Initial boiling point F.. 88 Per cent distilled at 212 F 34.0 Per cent distilled at 257 F.. 48.0 Per cent distilled at 356 F 85.0 Final boiling point F..- 407 The above blended gasoline was then handled by three diil'erent processes as follows:

Process 1 The petroleum fraction was distilled taking overhead 24% light ends. The bottoms were treated with 15 pounds of 98% acid per barrel of oil. The treating loss amounted to 19.4%, based upon the 011 being acid treated. The acid treated product was-then soda washed and rerun, taking overhead 88%. The overhead product was blended with the original light distillate and the total sweetened.

Process 2 The petroleum fraction was distilled and 60% light ends removed overhead. The bottoms were then treated with 35 pounds of 98% sulfuric acid. The treating loss was 26%, based upon the oil being treated. The acid treated bottoms were then soda washed and rerun, taking 88% overhead. The overhead was blended with the original bypassed distillate and passed through clay at a temperature of 450 F. and then sweetened.

Process 3 The entire petroleum fraction was passed through bauxite at a temperature of about800 F. and then passed through clay at 410 F. at atmospheric pressure. The bauxite and clay treated distillate was washed with sodium carbonate. The washed distillate was distilled and 75% light ends removed overhead. The bottoms were treated with 25 pounds of 98% acid per barrel of oil.

The treating loss amounted'to 10%, based upon the oil being acid treated. The acid treated bot- EXAIVIPLE 5 A low sulfur East Texas gas oil having a gravity of 333 A. P. I. was cracked in a once-through I coil operation at a temperature of 1025 F. and

at a pressure of about 60 pounds per square inch gage. The naphtha distillate was then passed through bauxite at a temperature of about 800 F. and then through clay at a temperature of m about 500 F. Inspections were determined on the naphtha distillate before and after passing through the bauxite and clay with the following results: a

TABLE Total 800 F 500 F Naphtha mspeeuon distillate .bauxite and clay Yield volume I00 97. 0 Gravity A. P. I... 56. 6 57.3 Sulfur detcrminatio 0. 040 0.025 Color o) Colorhoid l6 hrs. at 212 F" 26 Breakdown .minutes. 30 30 +5 mg. U. 0. P. #4 inhibitor per 1000 gals 105 220 Copper dish gum 99 27 +5 mg. U. 0. P. inhibitor per 1000 gals. 36 5 Octane No. clear (A. S. T. M.) 66.6 76.1 +1 0. tetraethyl lead (A. S. T. M.) -73. 0 80. 3 [hit al boiling point, Engler .F.. 84 99 Per cent distilled at 212 F., Engler-.. 34 35 Per cent distilled at 257 F., Engler. 52. 5 55 Per cent distilled at 357 F., Engler. 88.0 88.5 Final boiling point, Engler F 403 396 Analysis:

Per cent oleflns 70 75 Per cent aromatics 14 15 N aphthas+paraillns l0 10 l 18 Robinson. I +28 Saybolt.

toms were soda washed. rerun and blended with w Acid required, 98% H2804 Process 1 lbs. per barrel 11.4 Process 2 do 14.0 Process 3 do 7.2

The inspections of the gasoline produced by the respective processes were as follows:

TABLE 9 Proc- Proc- Proccss 1 ess 2 ess 3 Yi ld volume .per cent 83. 0 R7. 3 04. 4 Gravity A. P- l 55. 4 55. 8 54.1 Sulfur determination. ...p(-r cent. 0. 104 0. 104 0. 098 olnr (Sayholt)v 26 26 28 folorhold15 hrs. at 212 F.. 23 23 26 Breakdown minutes 15 10 15 +0.4 1h. U. 0. l. #1 inhibitor per 1000 gals. 260 285. 855 (ripper dish cum mg. 59 115 61 +0.41h. U. 0. P. #4 inhibitor per 1000 gals. 14 0 Octan No. clear (A. S. '1. M.) p 75. 7 77. 5 78. +l 'icc.h 1racthyllead (A. S. 'T. M.) 81.3 +300. ietracthyl lead (A. S. 'l. M.) 81.5 82.4 82.7

From the above data it is to be observed that a considerably higher yield was secured by Proc ess 3 with an appreciable saving in acid. It is also to be observed that the octane number of the gasoline produced by Process 3 was considerably hi-gher than the octane number of the gasoline produced by Process 1 or Process 2.

From the above data it is the octane number was considerably improved by passing through bauxite and clay and that very little, if any, polymerization resulted.

EXAMPLE 6 A low sulfur East Texas gas oil was cracked at a pressure of 740 pounds per square inch and at a temperature of 940 F. The naphtha distillate was passed through bauxite-at a temperature of about 800 F. and through clay at a temperature of about 400 F. The inspections of the naphtha before and after treatment were as follows:

TABLE 11 Rerun 800F. 500 F. 400 F. bauxite and end point clay Yield volume per cent. 03.0 92. 0 Gravity A. P. I 58. 3 57. 6 Sulfur determination .per cent.. 0. 260 0. 170 Color Robinson. +26 16 hrs. at 212 F +26 Breakdown. ..minutes.. 30 +5 mg. U. 0. P. #4 inhibitor per 1,000 gals 220 Copper dish gum 16 18 +5 mg. U. 0. P. #4 inhibitor per 1,000 gals 5 Octane No. clear (A. S. T. M.) 68 70 +156 cc. tetraethyl lead (A. S. T. M.) 74 77 30c. tctracthyl lead (A. S. T. M.) 77 78 EXAMPLE 7 A high sulfur West Texas gas oil was cracked at a temperature of 925 F. and at a pressure of about 750 pounds per square inch. The cracked distillate was handled by various means with the following results:

to be observed that TABLI 12 am? Process 2 Process 3 and rerun 1 end point pres Yield volume. per cent. 87 84 84 GravityA. 57.1 50.2 56.7 :gnllur determination per cent 3g 01:13; 04123 01 hrs at 212 F +14 +2! Aniline point 108 mo 10? Acid treat 39 31 3o Breakdognb. P1. .fiifiii. 95 25 35 n or +5 mg per 1,000 gals. 305 420 605 Copper dish gum 17 25 24 +5 mg. U. 0. P. '4 inhibitor per 1,000 gals 6 8 7 Octane No. clear (A. S. 'I. M.) 86. 0 87.1 08. 4 13600. tetraeth llead 72.1 73.5 74.0 800 tetraethyl esd 76.0 77. 2 78. 1 initial boiling point, Engier. 95 03 04 Percent distilled at 212 F., Engier. 27. 8 '26 28. 5 Percent distilled at 267 F., Engler. 42. 8 40 41 Percent distilled at 874 F., Englen. 88. 5 88 80. 5 Final boiling point, Englar. F 410 412 408 It is apparent from the above data that the bauxite and clay treat have little effect on a petroleum oil cracked in the liquid phase.

EXAMPLE 8 I A gas oil was cracked in the vapor phase at a pressure or about 60 pounds gage and ata temperature of 1060 F. The cracked distillate was passed through bauxite at atemperature of about 800 F. and through clay at a temperature of about 500 F. Atmospheric pressure was empioyed on the bauxite and clay treat. Feed rates through the bauxite and clay treat were one liquid volume per volume of bauxite and per volume of clay per hour.

The octane number improvements secured by the bauxite and clay treat were as follows:

treat further improves the octane number characteristics of the fuel.

The process of the present invention is not to be limited byany theory or mode of operation, but-only by the following claims in which it is desired to claim all novelty in so far as the prior art permits.

We claim: v

1. Process for the production of high quality, high octane number motor fuels comprising cracking a petroleum oil in the vapor phase at a pressure in the range below about 60 pounds gage and at atemperature in the range fromabout 1100 F. to l400 FL, passing cracked petroleum fractions boiling in the gasoline range through bauxite at a temperature in the range from about 800 F. to 850 F., then passing said bauxite treated oil through clay at a. temperature in the range from about 340 F. to 500 F., cooling said petroleum oil to secure said high quality motor fuels.

2. Process for the production of high quality, high octane number fuels comprising cracking a petroleum oil, boiling in the gas oil range and having about 90% distilled at 900 F., in the vapor phase at a pressure in the range below about 60 pounds gage and at a temperature in the range from about 1100 F. to 1400 F., passing cracked petroleum fractions boiling in the gasoline range through bauxite at a temperature in the range from about 800 F. to 850 F,, then passing said bauxite treated oil through clay at a temperature in the range from about 340 F. to 500 F., co0iing said petroleum oil to secure said high quality motor fuels.

3. Process for the production of high quality motor fuels from petroleum oils comprising 7 cracking a petroleum oil in the vapor phase at a The above data demonstrate that the clay pressure in the range from about 0 pounds to 200 pounds gage and at a temperature in the range from about 975 F. to 1400 F. under conditions in which a cracked fraction boiling below about 400 F. is segregated and removed overhead in a fractionating tower. heating said segregated cracked fraction to a temperature in the range from about 800 F'. to 850 F. and passing the same through bauxite in order to produce said high quality motor fuel.

-AMIO'I P. HEWLETT. GERALD E. PHILLIPS.

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