US2317766A

US2317766A - Refining petroleum oils

Info

Publication number: US2317766A
Application number: US312198A
Authority: US
Inventors: Amiot P Hewlett; Gerald E Phillips
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1940-01-03
Filing date: 1940-01-03
Publication date: 1943-04-27
Anticipated expiration: 1960-04-27

Description

April 27, 1943. A. P. HEWLETT ErAL.

REFINING PETROLEUM CIL 'III-II' LZ v. n 95. tw K D IN NOLIN mu NeR N NR. NGL (Nntq Filed Jan. 3, 1940 www! 0L EQ Qu QQ R EO uNm...

Nub Gi Patented Apr. 27., 1943 i REFININ G PETROLEUM OILS Amiot P. Hewlett, Summit, and Gerald E. Phillips,

Cranford, N. J., assitnors to Standard Oil Development Company, a corporation of Dela- Application January 3, 1940,'Serial No. 312,198

11 Claims.

The present invention relates to a process for the refining oi petroleum oils. The invention is particularly concerned with a process for the production of improved motor fuels having high anti-knocking characteristics as measured by a high octane number, which comprises bauxite treating feed oils of particular characteristics. In accordance with the present invention, petroleum oils are processed under conditions adapted to produce products boiling in the motor fuel boiling range and characterized by having high acid heats and relatively low clear octane numbers. These oils are then contacted with bauxite under suitable conditions to produce high quality motor fuels.

It is known in the art to desulfurize petroleum oils by contacting feed oils with bauxite at elevated temperatures by various processes. For example, it is known to remove objectionable sulfur compounds from virgin feed oils by contacting the same with bauxite at temperatures in the range of about 600 F. to 650 F. It is also known to treat distillates boiling in the motor fuel boiling range secured from various cracking operations with bauxite at temperatures in the range from about 600 F. to 800 F. In these operations, the oils which are bauxite treated have been previously processed in a manner to secure a product having the highest clear octane number. Thus, for example, it is known to bauxite treat petroleum oils which have been cracked under conditions adapted to produce cracked products having relatively high octane numbers and having relatively low acid heats. We have now discovered that unexpected desirable advantages are secured providing the character of the feed oils is controlled so that the bauxite not only functions as a desuliuriza-l tion agent, but also functions in a manner to T. M.) are bauxite treated at optimum temperature and pressure conditions.

I'he process of our invention may be readily understood by reference to the attached drawing illustrating one modification of the same. For the purpose of illustration it is assumed that the feed oil of this character is produced by a thermal cracking operation. Feed oil is introduced into primary bubble tower I by means of fresh feed line 2. For purposes of illustration it is assumed that the feed oil is a gas oil boiling in the range from about 400 F. to 700 F. The feed oil is withdrawn along with recycle oil from the bottom of preliminary bubble tower I by means of line 3 and introduced into heating coil 4. Heating coil 4 comprises suitable convection and radiant sections. The oil is passed through heating coil 4 andraised to the desired cracking temperatures. The heated oil, under cracking temperatures, is withdrawn from heating coil 4 by means of line 5 and passed into reaction chamber or soaking drum 6 in which the oil is'maintained for the desired time period under conditions adapted to control the cracking operation. The oil is withdrawn from reaction chamber 6 by means of line 1, passed through pressure release valve 8, and then flashed in tar separator 9 from which substantially all the oil is removed overhead by means of line II as a vapor. Tarry materials are withdrawn from separator 9 by means of line I0 and removed from the system. The overhead vapors from separator l0 are introduced into primary bubble tower I. Temperature and pressure conditions are maintained on bubble tower I adapted to separate a cycle oil which is removed wth the fresh feed by means of line 3 and -to remove overhead by means of line I2 a distillate product of the desired endpoint. The overheadproduct from bubble tower I is kintroduced into secondary bubble tower I3. Temperature and pressure conditions on tower I3 are similarly adapted to segregate a heating oil or equivalent fraction which is withdrawn from the bottom of the tower by means of line I4 and removed from the system. An overhead product of the desired endpoint, preferably in the range from about 400 F. to 420 F.. is removed by means of line I and bauxite treated as desired. The overhead fraction removed from tower I3 by means of line I5 may be heated in heater I6 prior to contacting the overhead with bauxite in bauxite treating unit I'I. The bauxite treated oil is withdrawn from bauxite treating unit I'I and preferably passed through clay contacting unit I9. The clay contacted oil is withdrawn from clay contacting unit I9, passed through cooler and then introduced into distillate drum 2i Condensed distillate is withdrawn from distillate drum 2I by means of line- 25, while overhead vapors are removed by means of line 22.

The process of the present invention may be widely varied. Under certain conditions it may be desirable to condense the overhead distillate in condenser 21 and to pass the condensed distillate into distillate drum 28. The condensed distillate is removed from drum 28 by means of line 30, passed through heating unit I6, bauxite treating unit I1 and the clay contacting unit I9 as described. Uncondensed gases are removed from drum 28 by means of line 29. With certain feed oils the bauxite treated product may bypass the clay contacting plant by means of line 3l. Gases may be recycled with the fresh feed from the respective drums 28 and 2| by means of line 24. These gases may be heated inheater 32. Gases from the respective distillate drums likewise may be recycled with the feed to the bauxite treating unit by means of line 26.

The feed oils passed to the bauxite treating unit in accordance with the process of the present invention are cracked petroleum oils having acid heats in the range of above about 150 (A. S. T. M.) and clear octane numbers in the range below about 70 as determined by the A. S. T. M. method. In general, the feed oils are those oils which have acid heats in the range above about 225 and clear octane numbers below about 65.

'Especially preferred oils are cracked petroleumV oils having acid heats in the range above about 260 and clear octane numbers in the range below about 62. These oils may be secured in any desirable manner. However, a preferred source of feed oils of this character is from controlled thermal cracking operations in which modied cracking conditions are employed and in which a maximumoctane number is not secured in the cracked product. Cracking conditions are, in general, adapted to produce oils having high acid heats and having relatively intermediate or low octane numbers.

The cracking operations will be a function, to some extent, of the particular feed oil being processed. In general, the cracking conditions best suited for the production'of cracked oils of relatively high acid heats and intermediate octane numbers are relatively mild cracking operations in which the coil outlet temperatures employed are in the range belowabout 930 F. and the pressures employed are in the range below about 500 pounds per square inch. In general, it is preferred that the feed oils for the -bauxite treating unit be cracked distillates secured from cracking operations in which the feed oils are gas oils boiling in the range from about 400 F. to 700 F., which cracking coil feed oils are cracked at temperatures in the range below 900 F. and at pressures below about 300 pounds per square inch. 'I'he distillate oils of this character are bauxite treated at any desirable temperatures or pressures. However, in general, it is preferred that the oils be contacted with bauxite at a temperature in the range from about 600 F. to 900 F., preferably bauxite treated at a temperature in the range from above about 800 F., as for example at a temperature of from 810 F. to 820 F. The pressure in the bauxite treating unit may vary widely. Although atmospheric pressure may be employed, elevated pressures are desirable. Preferred pressures are in the range above about 100 lbs. per square inch, preferably-in the range of about 300 to 450 lbs. per square inch and higher.

In order to further illustrate the invention, the following examples are given which should not be construed as limiting the same in any manner whatsoever.

Example 1 Various operations were conducted in which gas oils boiling in the range from about 400 F. to 700 F. were thermally cracked under various temperature and pressure conditions. The operating conditions, as well as the acid heats and the base octane numbers of the cracked distillates were as follows:

Table 1 Gas oil cracking conditions Base m r n fqlo' 1Pressure A BTM' A. B.T M

outlet bs./sq. in.

Operation A 875 300 operation Bm-. 93o 300 ig gl Operation 0..... 851 300 204 66. 5 Operation D 900 300 180 60 5 operation E 875 125 17e 651e 905 1,000 100 64. 6 915 1, 000 100 65.0 905 1,000 86 65. 7 I 850 2, 000 70 55. 1 Operation J' 880' 2, 000 88 59. 2 Operation K- 910 2, 000 82 64 l operation 915 750 9o calo The octane number improvements of the above distillates by bauxite treating at 800 F. to 820 F. are as follows:

From the above data it is apparent that the cracked distillates produced by operations A to E, inclusive, were materially more susceptible to octane number improvement by bauxite treatment than stocks produced by operations F to L, inclusive, and that an apparent critical differ- A ence exists.

Table 3 Opera- Opera- Opera- Opera- Operation M tion N tion O tion P tion Q Base octane number 66 6 67.8 70.7 04.2 61.3 Acid heat 294 243 293 154 238 Treated octane number 76.1 76 1 75. 9 69. 2 70. 4 Improvement 9. 5 8. 3 5.2 5.0 9. 1

Operation M Operation N Operation 0- Inspections Inspections Inspections Treated t Treated Treated Feed stock Feed stock Feed stock Per cent sulfur. 0. 046 0.025 0.030 0.023 0.031 0.019 8.5 28 0 28 -9 2T Gravity.. 56. 6 57. 3 61. 6 61. 3 60. 4 60. 0 Naphtha distilled (Eugler):

I nitial boiling point. 84 F 89 F. 81 F. 81 F 88 F. 91 F Per cent distilled atl58 F-. 15. 0 14. 0 22. 0 21. 0 20. 5 19. 0 212 F 34.0 35. 0 38.0 38. 5 40.0 40. i 2577 F-. 52. 5 55. 0 52. 5 54. 0 56. 5 58. i) Final boiling point- 403 F. 390 F. 403 F. 392 F 401 F. 304 F Operation P- Operation Q- lnspections Inspections Treated Treated Feed stock Feed stock 0. 034 0.025 0. 042 0. 032 -ll 3U -9 +30 Gravity 60. 60. 7 61.0 60.4 Naphtha Distilled (Engler):

Initial boiling point-. 90 1 09 F. 93 F. 100 F. Per cent distilled 158 F..- 10.0 14.5 15.0 13.0 212 F. 33.5 33.0 31.0 31.() 257 F 8. 5 49. 5 45. 5 42. 5 Final boiling point... 400 l* 392 F. 405 F. 400 l".

Further operations were conducted on additional cracked distillate oils with the following results:

Table 4 Operation B. Operation S Base octane number. 49. 7 05. 2 Acid heat 30 70. 0

Treated octane number 53. 9 67. 1 improvement 4. 2 1. 9

Treated Treated ned stock Feed stock 0. 050 0. 026 0.037 0. 019 7 27 2l 30 Gravity 43. 2 43. 2 61. 8 61.8 N laphtha distilled (Eng- Initial boiling point.. 252 l". 144 F 90 F 00 F. l'cr cent distilled atl5i4 F 1B. 5 18.0 37. 0 38. 0 00. 0 00. 0 302 .0 77. 0 Final boiling point... 399 F 305 F.

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

We claim:

1. Process for the production of motor fuels having high anti-knocking characteristics comprising contacting petroleum feed oils characterized by having an acid heat above about 150 and a. clear octane number below about 70 with bauxite at a temperature in the range from about 800 F. to 850 F.

2. Process in accordance with claim 1 in which said temperature is in the range from about 810 F. to 820 F.

3. Process in accordance with claim 1 in which said petroleum oils have acid heats in the range above about 225 and clear octane numbers below about 65.

4. Process in accordance with claim 1 in which said petroleum oils have acid heats in the range above about 260 and clear octane numbers in the range below about 62.

5. Process for the production of high quality motor fuels having high anti-knocking characteristics which comprises subjecting feed petroleum oils to cracking temperatures and pressures adapted to produce distillates boiling in the motor fuel boiling range having acid heats in the range above about 150 and clear octane numbers in the range below about 70, treating said oils with bauxite at a temperature in the range from about 810 F. to 820 F.

6. Process in accordance with claim 5 in which said cracking temperature is in the range from about 800 F. to 850 F.

7. Process in accordance with claim 5 in which said feed oil is a gas oil boiling in the range from about 400 F. to 700 F. and said cracking temperatures are below about 900 F. coil outlet and said cracking pressures are below about 300 pounds per square inch.

8. Process in accordance with claim 5 in which said feed oil is a gas oil boiling in the range from about 400 F. to 700 F. and said cracking temperatures are below about 875 F. and said cracking pressures are below about 125 pounds per square inch.

9. Improved process for the production of motor fuels having high anti-knock characteristics comprising subjecting a feed oil boiling in the range from about 400 F. to 700 F. to a cracking temperature below about 930 F. and a cracking pressure below about 300 lbs/sq. in., whereby a motor fuel having an A. S. T. M. octane number below about 70 and an A. S. T. M. acid heat above about 150, and boiling in the range from about F. to 400 F. is produced, segregating said motor fuel and contacting the same with bauxite at a temperature in the range from about 800 F. to 850 F.

10. Process as defined by claim 9 in which said temperature at which the motor fuel is contacted with bauxite is in the range from about 810 F. to 820 F.

l1. Improved process for the production of motor fuels having high anti-knock characteristics comprising subjecting a feed oil boiling in the range from about 400 F. to 700 F. to a cracking temperature below about 850 F. and a cracking pressure below about 300 lbs./sq. in., whereby a motor fuel having an A. S. T. M. octane number below about 67 and an A. S. T. M. acid heat above about 200, and boiling in the range from about 100 F. to 400 F. is produced, segregating said motor fuel and contacting the same with bauxite at a temperature in the range from about 800 F. to 850 F.

AMIOT P. HEWLETT.

GERALD E. PHILLIPS.