US3247095A

US3247095A - Hydrocarbon coking process to produce lubricating oils and waxes

Info

Publication number: US3247095A
Application number: US321646A
Authority: US
Inventors: John W Conwell
Original assignee: Sunray Dx Oil Co
Current assignee: Sunray Dx Oil Co
Priority date: 1963-11-05
Filing date: 1963-11-05
Publication date: 1966-04-19
Anticipated expiration: 1983-04-19

Description

pril 19, 1966 J. W..coNWELL 3,247,095

HYDROCARBON COKING PROCESS TO PRODUCE LUBRICATING OILS AND WAXES INVENTOR. wd M( gama@ April 19, 1966 .1. w. coNwE-LL 3,247,095

HYDROGARBON COKING PROCESS TO FRODUCE LUBRIGATING OILS AND WAXES Filed Nov. 5, 1963 2 Sheets-Sheet 2 United States Patent O 3,247,095 HYDROCARBON COKING PROCESS T PRODUCE LUBRECATING OILS AND WAXES John W. Cornwell, Tulsa, mda., assigner to Sunray DX Oil Company, Tulsa, Okla., a corporation of Delaware Filed Nov. 5, 1963, Ser. No. 321,6@36 9 Claims. (Cl. 20S-96) This invention relates in general to the conversion of petroleum oils to produce therefrom lubricating oils and petroleum waxes of high quality. More specifically, the invention relates to the production of high quality lubricating oils and petroleum waxes from distillate stocks resulting from coking operations.

The initial processing of crude petroleum oil in a modern oil renery is more or less standardized. The crude oil is generally first subjected to distillation at relatively low pressure with fractionation of the crude oil to produce gas, light naphtha, heavy naphtha, keroesne and/ or jet fuel distillate and light gas oils, as the principal products. The reduced crude oil can then be subjected to further reduction by distilling it, usually under vacuum, to produce gas oils of various distillation ranges. These gas oils may be used for lubricating oil and wax manufacture or may be catalytically cracked to produce additional quantities of fuels boiling in the gasoline and distillate boiling ranges. The residual crude from the vacuum distillation operation may be employed for lubrieating oil manufacture or it may be used as charge stock to a coking reactor.

Coking operations are generally carried out under drastic conditions utilizing temperatures of from about 800 to 1000 F. to produce volatizable products (gas, gasoline, kerosene, gas oils) and coke. The gas oils produced in the coking operation are frequently employed as charge stocks for catalytic cracking even though they are known to be poor stocks for this service because of their propensity to form carbon on the cracking catalyst and thus limit the effectiveness of the cracking catalyst.

A coking charge stock is composed mainly of vacuum reduced crude oils, but also may contain such stocks as extracts from various lubricating oil extracting operations, propane extracted asphalts, cylinder stocks, and almost any other stock that is not suitable for processing in the catalytic cracking operation. A typical charge stock to a coking unit in a modern refinery may have approximately the following average composition:

Vol., percent Vacuum reduced crude 65 Lube extracts 19 Propane extract (asphalt) 8 Cylinder stock 8 Total 100 It has now been found that high quality lubricating oils and petroleum waxes can be produced from distillates resulting from petroleum coking operations. The present invention is therefore directed to a process for producing lubricating oils and waxes from gas oils produced by petroleum coking operations thereby advantageously utilizing these gas oils in a novel manner rather than as charge stocks for catalytic cracking operations as is customary practice. According to the present invention, distillates boiling in the lubricating oil range which are produced in petroleum coking operations are separated and processed to produce high viscosity index lubricating oils and petroleum waxes of novel properties. The processing of the lubricating oils includes the steps of solvent refining, solvent dewaxing and, if desired, can include the steps of acid treating and clay contacting,

One important characteristic of a lubricating oil indic- ICC ative of quality is its viscosity index; that is, the resistance of the oil to change in viscosity with change in temperature. As a general rule in the petroleum industry, commercial lubricating oils must have a viscosity index of or higher to be considered satisfactory high viscosity index lubricating oils. In accordance with this invention, lubricating oils having viscosity indices of 95 and higher can be consistently produced in high yields from coking distillates Moreover, the lubricating oils produced by the process of the invention have outstanding oxidation stability and are superior to conventional lubricating oils for service where high temperatures and oxidation conditions coexist In addition to the highquality lubricating oils, the process of the invention provides petroleum waxes having melting points generally in the range of 122 to 132 F. and which are eminently satisfactory for all uses for which such petroleum waxes are normally employed.

The manner of carrying out the process of the present invention as well as the advantages thereof will be more readily understood from the following description in conjunction with the accompanying drawings in which:

FIGURE i is a schematic flow diagram showing diagrammatically the coking of a charge stock and fractionation of the Coker distillate in accordance with the present invention;

FIG. H is a schematic flow diagram showing the refining of the coker distillate to produce lubricating oils and waxes in accordance with the invention;

FIG. III is a diagrammatic tiow diagram showing steps concerned with the recovery of extraction solvents employed in .the process of the invention;

FIG. IV is a diagrammatic `showing of an alternate solvent recovery process sequence.

Referring to FGURE I, a coking charge stock, such as that described above, is passed through line i1 into surge tank i2 which connects with coker product fractionator 1d whereby the bottoms therefrom can be collected in the surge tank for recycling to the coking operation. A combined coker charge stock from surge tank 12, including fresh stock and bottoms from fractionator i4, is transferred via line 13 to the heater 16 wherein it is heated to a temperature ranging from about 875 to about 985 F. depending upon the nature of the charge stock and heater limitations. From heater 16 the charge passes through line 17 into the coker i8. For good rates of conversion of the coking charge and maximum production of volatilizable products, coker i8 is operated at a temperature in the range from about 800 to l000 F., preferably 8;50 to 950 F. and a pressure of from 10 to psig., preferably 2O to 30 p.s.i.g. Lump coke is hydraulically removed from coker 18 via line i9 while overhead vapors from the coker pass through line 20 to coker product fractionator 14. Fractionator 1d is operated at suitable conditions so as to separate a gas stream, gasoline, a relatively light gas oil fraction and a heavier gas oil fraction boiling substantially in the lubricating oil boiling range which is further processed in accordance with the present invention. Thus, for example, fractionator i4 is operated under a pressure of approximately 7 psig. to take overhead through line 21 (at a temperature of about 267 F.) a gas and gasoline fraction. The gasoline in this fraction can be condensed and either returned as reflux through line 22 to the fractionator 14 and/or discharged through line 23 as product. A light coker gas oil is withdrawn as an upper sidestream through line 24 at a temperature of about 440 F. This product is cooled and a portion thereof returned to the fractionator as reflux through line 2S, while the remainder is discharged as product. A heavier Coker gas oil boiling substantially in the lubricating oil boiling range, that is, about 90% thereof boils above about 550 F., is withdrawn at a temperature of about 665 F. from the lower section of fractionator 14 through line 28. Upon cooling, a portion of this sidestream can be internally refluxed to fractionator 14 through line 29 with the remainder thereof being removed for further treatment in accordance with the present invention. The bottoms from fractionator 14, consisting of heavier asphaltic materials, accumulate in surge tank 12 and mix with the fresh coking stock being charged through line 11.

The relatively heavy coker gas oil which is withdrawn from fraetionator 14 at sidestream 2S is then processed to a finished lubricating oil by a series of refining treatments including solvent extraction, solvent dewaxing, acid treating and clay treating. The relatively heavy gas oil is conveniently subjected to refining with a solvent such as furfural, sulfur dioxide, dimethylsulfoxide, chlorex or phenol, to remove cyclic and olenic and other undesired compounds present in the oil in order to thereby improve the viscosity index of the oil. A preferred solvent for this purpose is furfural. The refining process admits of flexibility and the relatively heavy gas oil may or may not be dewaxed prior to the solvent extraction step depending upon the type of solvent and the conditions employed in the solvent extraction. As is known in the art, with some solvents miscibility of the separated oil is such that phase separations may occur at temperatures which necessitate dewaxing the oil before solvent extraction, while with other solvents miscibility occurs at temperatures sufficiently high so that it is not necessary to dewax prior to the solvent extraction operation.

A typical heavy cokcr gas oil utilized according to the present invention to produce lubricating oils and waxes may have the following inspection compared with a typical coking charge stock from whlch 1t 1s obtained:

Coker Distillate Coking charge product conditions stock (HC GO) Gravity API 16.4 23. 3 80G-895 F. Flash point, 580 300 21 p.s.i.g. Cold test, F- +60 +84 Viscosity SSU at 100 F 53, 500 139.0 Viscosity SSU at 210 F 640. 0 42. 4 Dstlation, F., D-1160:

IBP 681 442 5% Overhead.- 919 635 Overhead- 967 G71 Overhead 1, 020 709 50% Overhead (Cracked) l 1, 075 798 90% Overhead 943 The coker gas oil leaving fractionator 14 through line 28 is conveyed to a solvent extraction zone 32 (see FIG. II) wherein the oil is subjected to contact with a solvent exerting a selective solvent action principally towards aromatic and olefinic constituents. Solvent extraction zone 32 comprises a conventional countercurrent contacting unit to which a solvent such as furfural is introduced at a point near the top thereof as through line 30. While the contacting of the solvent and oil may be conducted in any desired contacting equipment of a batch or continuous nature, countercurrent treating technique is preferably employed with wide variation in operating conditions such as temperatures, solvent/oil ratios, etc., as is known to the art. Extracting tower 32 is provided with packing, perforated plates, rotating discs or equivalents, to secure effective liquid-liquid contacting. The oil passes upwardly through the tower while the solvent passes downwardly through the tower, permitting removal from the bottom of the tower of what is known as an extract phase through line 33. The extract phase will consist principally of the solvent such as furfural together with the constituents selectively extracted from the oil consisting principally of aromatic and olefin hydrocarbons. The material withdrawn from the top of tower 32 through line 34 is known as the raffinate phase and consists principally of the initial heavy coker gas oil feed minus the aromatic constituents originally present therein, admixed with small proportions of the solvent employed during the contacting. The raffinate is passed to a raffinate stripping column 36 wherein residual solvent is driven overhead through line 37 while the solvent refined lubricating oil product is removed as a bottoms product through line 39. The oil stream of line 39 derived as indicated is then conducted to suitable dewaxing facilities identified by rectangle 40 on the drawing. The operation conducted in zone 40 can be chosen from any of the conventional dewaxing processes of a nature to reduce the wax content of the hydrocarbon fraction treated to any desired extent. In general, it is preferred that a solvent dewaxing operation be employed. One commercial solvent dewaxiug process is the ketone dewaxing process. While other ketones may be employed in this process it has been the general practice to employed methyl ethyl ketone (in admixture with aromatics such as toluene) as the solvent so that the process has generally been known as the methyl ethyl ketone, or MBK dewaxing process. Commercial MEK dewaxing processes simply require the addition of a suitable quantity of the MEK solvent to the oil to be dewaxed so as to permit complete solution of all wax present in the oil when the mixture is heated. After the wax has been dissolved, and upon cooling the mixture of oil and ketone, the wax is precipitated and is removed from the oil by filtration. In a preferred manner of dewaxing the waxy oil is diluted with some solvent (primary) and is cooled, then additional solvent (secondary) is added on further cooling, and the resultant wax crystals separated from the dewaxed oil by filtration and washed with solvent. Typical preferred dewaxing conditions are as follows:

Primary solvent/Charge oil ratio 0.75/ 1 Secondary solvent/Charge oil ratio 1.25/ 1 Wash solvent/ Charge oil ratio 1.10/ 1 Filtration temperature, F. -15 Solvent, MBK/Toluene, vol. percent 45/55 Following dewaxing at 40 the solvent refined, dewaxed, lubricating oils are subjected to acid treating at 42 and clay filtered at 44 to a finished lubricating oil status. Acid treating at `the zone identified by rectangle 42 is employed to improve the color, stability and resistance to oxidation of the oils and generally consists in treating the dewaxed oil with five pounds of 93% sulfuric acid per barrel of oil at a temperature of around to 110 F. After removing the resultant sludge, the acid treated oil is contacted with a small amount of water (0.1 to 0.2% by weight) to coagulate any pepper sludge which is then removed on settling. The washed oil is then contacted or filitered with adsorbent clay or bauxite (1 ton clay/ 8000 gallons oil) at zone 44 to further improve the color and to neutralize the oil after acid treating. Inspection of two typical finished lubricating oils produced by the process of the present invention is as follows:

Finished Finished lubricating lubricating Treatment stock #l stock #2 Gravity, API 28. 2 32. 1 5 lbs. acid/ 380 385 bbl. 8,000 +8 +2 gal./ton 130. 5 124. 2 Clay. Vis. index. 100. 7 118. 2 Color, ASTM D-1500 L4 L2 It will be observed that the finished lubricating oils have viscosity indices of 100.7 and 118.2, indicating that the process of the invention is operative to provide high viscosity index lubricating oils. Moreover, the lubricating oils produced in accordance with the invention are characterized by their outstanding resistance to oxidation in comparison with commercial lubricating oils having similar viscosity characteristics. One test for evaluating the oxidation resistance of lubricating oils is 4known as the Indiana oxidation test wherein the lubricating oil is subjected to controlled oxidation conditions and the reaction sludge formed quantitatively determined.. `Commercial lubricating oils prepared by conventional processes have been found to posse-ss an Indiana oxidation rating of approximately 17 hours, which is the time required to form a specific quantity of sludge, whereas lubricating oils of similar viscosity characteristics produced in accordance with this invention have been found to possess ratings above 100 hours.

The crude wax separated from dewaxing at 40 is ltransferred via line 45 to suitable deoiling facilities at 46. Deoiling of the wax at 46 can be accomplished according to conventional procedures by dispersing the crude wax in a deoiling solvent and chilling t-o a `temperature (usually higher than the dewaxing temperature) so as to thoroughly contact (repulp) the wax while leaving any contaminating oils and/or .soft waxes in `the deoiling solvent. The deoiling solvent can be the same as that employed for dewaxing, such as for example 45% vol. MBK and 55% toluene. tPrefera-bly, a two-stage deoiling procedure is employed; inthe first stage the crude wax, containing some solvent from the dewaxing operation, is heated with additional solvent in two stages of dilution and then chilled to cause precipitation of the iwax. The precipitated wax is liltered and the wax filter cake washed with solvent. The resultant wax filter cake is then repulped in additional solvent, filtered and again washed with solvent to produce a deoiled Wax, which is removed through line 47. The deoiled wax can be percolated over clay at 48 to improve the color thereof, with the finished deoiled wax being removed through line 49. The deoiled waxes so produced, in yields depending upon the original wax content of the coker gas oil employed, have melting points in the range of about 120 to 133 F. Petroleum waxes melting in the range of about 120 to 135 F. are used in large quantities in the dairy industry as an impregnant for paper and other containers for milk and other dairy products. The relatively high melting points of the waxes produced by the process of the invention as well as their exceptional adhesion and sealing strength properties render ythem eminently suitable for use as dairy waxes. The waxes of this invention are generally from 3 to 4 times more adhesive than waxes of comparable melting point prepared :by prior art processes and their sealing strength characteristics are from 4to l5 times greater. A typical deoiled wax product obtained at 49 has the following physical properties:

Color, Saybolt |30 Refractive Index at 212 F. 1.4255

Gil Content, Wt. percent 0.16 Paraflin M.P., F. 126 Penetration at 77 F 5l Absorptivity at 290 mu 0.011

A wax product resulting from deoiling at 4-6 is found to be relatively soft with a congealing point of approxiimately 70-75 F. and is suitable for use in polish formulations, etc. This soft wax product containing wax and raffinate oil can be removed through line 51 or percolated ove-r clay at 52 to improve its color, etc.

As described, the process of the invention for producing high quality lubricating oils and waxes involves the refining of a coking distillate with suitable solvents at solvent extracting zone 32 to remove aromatic and olenic compounds therefrom. The railinate stream 34 and extract stream 33 from solvent extractor 32 normally contain appreciable quantities of solvent and for economy and other processing advantages these streams are processed to achieve recovery of the solvent.

Referring t-o FIG. HI of the drawings which illustrates one processing scheme, the rainate stream from extractor 32 passes through line 34 to raffinate stripper 36. Steam for stripping the raliinate is introduced into the lower section of stripper 36 and passes upwardly therethrough. T-he stripped raffinate is discharged .from stripper 36 through line 39 and processed to provide `nished lubricating -oil and wax as previously described. The overhead from stripper 36 consists of steam, extraction solventand a portion of the hydrocarbon rafnate of somewhat lighter boiling range than the stripped ranate which is removed through line 39. These three components are passed via line 37 to condenser 54. Thereafter, the condensed mixture is passed through line 55 to a liquid separator 56 wherein the mixture separates into three phases. The top phase is principally a hydrocarbon layer which is removed through line SS and passed to stripping column 59; the middle phase is principally water which is passed through line 60 to stripping column 61; the third or bottom phase principally comprises solvent and is passed through line 62 to stripping column 63. Each of these separated phases are contaminated with the other two components, requiring that each phase stream be stripped free of the other components which is accomplished by means of

steam stripping columns

59, 61 and 63.

In column 59, the hydrocarbon phase is steam stripped and solvent and water present removed as overhead through line 65 for recycling, while the stripped hydrocarbon is discharged from the bottom of the stripper through line 66. In column 6l the water phase from separator 56 is steam stripped free of solvent and hydrocarbon; solvent and hydrocarbon being removed as overhead through line 68, while the water is discharged from the bottom of the stripper through line 69. In column `6ft the solvent phase from separator 56 is steam stripped with water and hydrocarbon leaving the stripper 63 as overhead through line 71 and the stripped solvent removed from the bottom of the stripper through line 72. This recovered solvent is recycled for further us-e in the solvent extraction operation at 32.

The extract stream from solvent extractor 32 passes through line 33 to extract stripper 74 and is steam stripped in a manner similar to the raflinate. The stripped extract is discharged from extract stripper 74 through line 76 and can be used for the manufacture of carbon black, coke and/or asphalt, as well as for other petroleum and petrochemical uses. The overhead from extract stripper 74, containing solvent, steam and a portion of the lighter hydrocarbons' present in the extract is passed through line 77 to condenser 78. The condensate from condenser 78 ilows through line 79 to liquid separator 80 wherein the mixture separates into three phases; a light hydrocarbon phase, a water phase and a solvent phase. Each separated phase contains some of the other components and each phase must be stripped in order to remove the minor components present therein. This is accomplished in similar manner as described above with reference to the raliinate stream. Thus, the three phases are separated and the top hydrocarbon phase is steam stripped in column 32, the water phase steam stripped in column 84, and the bottom solvent phase steam stripped in column 86. The overheads from stripping columns 32, 84 and S6, which are essentially steam and solvent, solvent an-d hydrocarbon, and hydrocarbon and water, respectively, are recycled to condenser 73.

FIG. lV illustrates an alternative processing scheme to that shown in FG. Ill. In this embodiment, a common recovery system is used to recover the extraction solvent and the light hydrocarbon product obtained as overhead from the raiiinate and extract

strippers

36 and 74.

Thus, the raffinate from solvent extractor 32 passes through line 34 to raffinate stripper 36 wherein it is stripped by means of steam. The stripped raffinate is removed through line 39 and processed to a nished lubricating oil as heretofore described. The overhead from rainate stripper 36 consisting of solvent, steam and a light hydrocarbon product, is passed through line 37 to condenser 88. Similarly, the extract from solvent extractor 32 passes through line 33 to extract stripper 74 wherein it is steam stripped. The stripped extract is'removed through line 76 w-hile the overhead from the stripper 74 consisting of solvent, steam and a light hydrocarbon product, is passed through line 77 to condenser 88. The condensate in condenser 88 representing the overheads from raffinate stripper 36 and extract stripper 74 is transferred through line 89 to liquid separator 90 wherein three phases separate. Each phase is then separately steam stripped in stripping

columns

92, 94, 95, with the overheads from each stripping column being recycled to condenser 88.

As indicated, the overheads from ratiinate stripper 36 and extract stripper 74 comprise the solvent utilized in the solvent extraction operation 32 and a light low boiling fraction of the hydrocarbon product comprising part of the rainate and extract streams from the solvent extraction. By processing these overheads as illustrated in FIG. III or FIG. IV, the solvent is substantially completely recovered for further use in the process and a light hydrocarbon oil obtained which is useful as a diesel fuel and/ or as a charge stock for catalytic cracking operations. Data concerning these overhead hydrocarbon products are Itabulated below. These data were obtained in two runs utilizing a 22.1 API gravity coker distillate having an initial boiling point of 418 F. and employing furfural as the extraction solvent. The processing sequence illustrated in FIG. III was employed and the following products were obtained:

The economic attractiveness of lubricating oil solvent extraction processes is, to a large extent, dependent upon the amount of solvent in relation to the oil (solvent/oil ratio) required to achieve a specific product quality. For example, at a solvent/oil ratio of 2/1, one-third of the charge to the extracting unit is oil and two-thirds of the charge is solvent. At higher solvent/ oil ratios, still greater proportions of the charge to the extracting unit is solvent. As a consequence, with high solvent to oil ratios much greater quantities of solvent must be recovered, thereby greatly increasing processing costs and capital investment for equipment.

In conventional lubricating oil extraction processes utilizing normal lubricating oil charge stocks, solvent/oil ratios on the order of 15/1 to 20/1 are required in order to achieve a lubricating oil product possessing a viscosity index of 11S-120. By means of the present invention, lubricating oils having desirably high viscosity indices 'of this order are produced utilizing relatively small amounts of solvent as indicated.

Those modifications and equivalents which fall within the spirit of the invention and the scope of the appended claims are to be considered part of the invention.

I claim:

1. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about S00 to 1000 F. a hydrocarbon oil containing constituents in part distilling Overheads Overheads Stripper Stripper Stripper Stripper 36 74 36 74 Operating Conditions:

Extractor top temp., F 200 2 0 Extractor, htm. temp., F-. 160 180 Solvent/Oil Ratio V/V 0.7/1 4/1 Yield, vol. percent (charge) 1. 8 0.7 5. 6 1. 0 Physical tests:

Gravity, A 38. 3 32.9 33. 7 35.0 Flash, COC, F 165 256 175 265 Cold test, F... -10 +30 0 +34 Viscosity, SSU at 100 F.. 33.9 48. 7 37 48 Carbon residue, rams. wt. percent.. 0, 07 0. 18 0.06 0.16 Color, D-1500 L1. 5 4. 5 L1. 5 4. 5 Sulfur, wt., pereent...- 0.12 0.21 0. 18 0.61 Aniline pt., 143. 6 166.6 144. 7 176. 0 Diesel index..... 55. O 54. 8 48.8 61. 6 Cetane index...- 06. 4 58. 7 48. 7 62. 5 Distillation, D1l60 F.:

IBP 308 420 348 432 420 544 489 540 488 618 536 612 572 694 598 706 682 754 650 760+ As seen, the above hydrocarbon products obtained as 1n the lubricating oil boihng range mto a cokmg chamber overheads from the raiiinate stripper 36 and extract stripper 74 are eminently suited for use as catalytic cracking charge stocks or as diesel fuels as indicated by the Cetane Index and Diesel Index values.

It will be apparent from the foregoing that by means of the process of the invention high quality lubricating oils and waxes are produced from charge stocks heretofore considered unsuitable for the production of such products. The major advantages of the improved process of the invention include the following: (1) an integrated coking operation contributing toward the production of high quality lubricating oils and petroleum waxes, (2) utilization of coker distillates for production of high quality lubricating oils, thereby eliminating the necessity for using these distillates as charge stocks for catalytic cracking operations and eliminating the catalyst contamination problems normally associated with such use, (3) the process provides in addition to the principal lubricating oil and petroleum waxes, hydrocarbon by-products which are valuable and have various uses, (4) a unitary continuous system enabling the recovery and re-use of solvents employed in the production of lubricating oil and providing desired control over the composition of products produced, and (5) significant economic advantages due to use of low solvent/oil ratio.

operated at a pressure of about 10 to 100 p.s.i.g., maintaining said charge therein at said elevated temperatures for a period sutiicient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and olefinic distillate heavy coker gas oil having a lower boiling range than the charge to the coking chamber but which boils in the lubricating oil distillation range with approximately boiling above 550 F., subjecting said heavy coker gas oil fraction to a series of refining steps including therein a solvent extraction step and a dewaxing step on the rafiinate therefrom to yield a lubricating oil and a wax product.

2. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 850 to 950 F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a coking chamber operated at a pressure of about 20 to 30 `p.s.i.g., maintaining said charge therein at said elevated temperatures for a period suiiicient to convert substantial amounts thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, withdrawing from said `fractionation a highly aromatic land oletinic distillate heavy coker gas oil having a lower boiling range than the charge to the colring chamber but which boils in the lubricating oil distillation range with approximately 90% boiling about 550 subjecting said heavy coker gas oil fraction to a series of refining steps including therein a solvent extra'ction step and a dewaxing step on the ranate therefrom to yield a lubricating oil and a wax product.n

3. A process for treatin-g hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 800 to 895 F. a hydrocarbon oil composed principally of reduced crude oil containing constituents in part distilling in the lub-ricating oil boiling range into a coking chamber operated at a pressure of about 2l .p s.i,g., maintaining said charge therein at said elevated temperatures for a period sucient to convert substantial amounts thereof to colte with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, withdrawing from said fractionation a highly aromatic and olefinic distillate heavy colter gas oil having a lower boiling ran-ge than the charge to the lcolcing chamber but which boils in the lubricating oil distillation range with approximately 90% boiling above 550 F., subjecting said heavy coker gas oil fraction to a series of refining steps including therein a solvent extraction step and a dewaxing step on the raiinate therefrom to yield a lubricating oil and a wax product.

4. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 800 to 1000 F. a

1 1 1 l 1 i hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a colring chamber operated at a pressure of about to 100 p.s.i.ig., maintaining said charge therein at said elevated temperatures for a period sufficient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and oleiinic distillate heavy Coker gas oil having a lower boiling range than the charge to the coking chamber but which boils in the lubricating oil distillation range with approximately 90% boiling above 550 F., contacting said distillate heavy coker gas oil fraction with a selective solvent for aromatic and olenic compounds to remove aromatic and oleinic compounds therefrom, dewaxing the solvent extracted distillate heavy coker gas oil raffinate fraction with a solvent capable of securing dissolution of the wax therein when cooled and recovering a solvent extracted dewaxed lubricating oil and the wax separated in said dewaxi-ng step.

5. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum Wax Iwhich comp-rises charging at a temperature from about 800l to l000 F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a colting chamber operated at a pressure of about 10 to 100 p.s.i.ig., maintaining said charge therein at said elevated temperatures for a period sufficient to convert substantial amounts of the components thereof to colte with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and olenic distillate heavy coker gas oil having a lower boiling range than the charge to the cokin'g chamber but which boils in the lubricating oil distillation range with approximately 90% boiling above 550 F., `contacting said distillate heavy coker gas oil `fraction with a selective solvent for aromatic and olefnic compounds to remove aromatic and oleinic compounds therefrom, dewaxing the solvent extracted distillate heavy coker gas oil raniate fraction with a solvent capable of scouring dissolution of the wax therein when cooled and recovering a solvent extracted dewaxed lubricating oiland Wax separated in said dewaxing step, and subjecting the solvent extracted dewaxed lubricating oil to treatment with acid and clay to improve the properties thereof. f

6. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises char-ging at a temperature from about 800 to 1000 F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a coking chamber operated at a pressure of about 10i to 100 p.s.i.g., maintaining said charge therein at said elevated temperatures yfor a period sulicient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and olenic distillate heavy coker gas oil having a lower boiling range than the charge to the coking chamber but which boils in the lubricating oil distillation range with approximately boiling above 550 F., contacting said distillate heavy coker gas oil fraction Iwith a selective solvent for aromatic and olefinic compounds to remove aromatic and olenic compounds therefrom, stripping with steam the rainate resulting from the solvent extraction, dewaxing the steam stripped raffinate with a solvent capable of securing dissolution of the wax therein when cooled, recovering a solvent extracted dewaxed lubricating oil and wax separated in said dewaxing step, condensing the overhead from said steam stripping operation, permitting .a phase separation to occur between the components of said overhead and then separating each of the components substantially free of the other components present therein.

'7. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 800 to 1000 F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a coking chamber operated at a pressure of about 10 to 100 p.s.i.ig., maintaining said charge therein at said elevated temperatures for a period sufficient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition iproducts to fractionation, and withdrawing from said fractionation a highly aromatic and olenic distillate heavy coker gas oil having a lower boiling range than the charge to the cokin g chamber but which boils in the lubricating `oil distillation ran-ge with approximately 90% boiling above 550 F., contacting said distillate heavy coker gas oil fraction with a selective solvent for aromatic and olefnic compounds to remove aromatic and olenic compounds therefrom, dewaxing the solvent extracted distillate heavy coker gas oil raffinate fraction with a solvent icapable of securing dissolution of the wax therein when cooled and recovering a solvent extracted dewaxed lubricating oil and wax separated in said dewaxing step, sub- ,jecting the solvent extracted dewaxed lubricating oil to itreatment with acid and clay to improve the properties thereof, deoiling said separated wax and percolating said deoiled wax through clay to recover Ia deoiled, claylpercolated wax prod-uct.

8. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 800 to 1000io F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a coking chamber operated at a pressure of about l0 to 100 p.s.i.g., maintaining said charge therein at said elevated temperatures for a period sufficient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and oleinic distillate heavy coker gas oil having a lower boiling range than the charge to the coking chamber but which boils in `the lubricating oil distillation range with approximately .90% boiling above 550 F., contacting said distillate heavy coker gas oil fraction with a selective solvent for aromatic and olenic compounds to remove aromatic and olefinic compounds therefrom, stripping with steam the raffinate resulting from the solvent extraction, de- `waxing the steam stripped raffinate with a solvent capable of securing dissolution of the wax therein when cooled, yrecovering a solvent extracted dewaxed lubricating oil :and wax separated in said dewaxing step, condensing ythe overhead from said steam stripping operation, permitting a phase separation to occur between the components of said'overhead and then separating each of fthe components substantially free of the other components :present therein, stripping with steam the extract resulting from the solvent extraction, condensing the overhead from said last-mentioned steam stripping operation, perrmitting a phase separation to occur between the components of said last-mentioned overhead and then separating each of the components substantially free of the other components present therein.

9. A process for treating hydrocarbon oil to produce a lubricating oil and a petroleum wax which comprises charging at a temperature from about 800 to 1000 F. a hydrocarbon oil containing constituents in part distilling in the lubricating oil boiling range into a coking chamber operated at a pressure of about 10 to 100 p.s.i.g., maintaining said charge therein at said elevated temperatures for a period sufficient to convert substantial amounts of the components thereof to coke with concomitant discharge therefrom of vaporous thermal decomposition products, subjecting the vaporous thermal decomposition products to fractionation, and withdrawing from said fractionation a highly aromatic and olenic distillate heavy coker lgas oil having a lower boiling range than the charge to the coking chamber but which boils in the lubricating oil distillation range with approximately boiling above 550 F., contacting said distillate heavy coker gas oil fraction with a selective solvent for aromatic and olenic compounds to remove aromatic and oleiinic compounds therefrom, stripping with steam the raffinate and extract resulting from the solvent extraction, dewaxing the steam stripped raffinate with a solvent capable of securing dissolution of the wax therein when cooled, 'recovering a solvent extracted dewaxed lu- .,-bricating oil and wax separated in said dewaxing step, condensing the overheads from said steam stripping operations, permitting a phase separation to occur between the components of said overheads and then separating each of the components substantially free of the other components present therein.

References Cited by the Examiner UNITED STATES PATENTS 2,049,000 7/1936 Day 208-96 2,943,995 7/1960 Mertes 208-96 3,013,960 12/1961 Axe et al 208-96 DELBERT E. GANTZ, Primary Examiner.

ALPHONSO D. SULLIVAN, Examiner.

A. RIMENS, Assistant Examiner.

Claims

1. A PROCESS FOR TREATING HYDROCARBON OIL TO PRODUCE A LUBRICATING OIL AND A PETROLEUM WAX WHICH COMPRISES CHARGING AT A TEMPERATURE FROM ABOUT 800 TO 1000*F. A HYDROCARBON OIL CONTAINING CONSTITUENTS IN PART DISTILLING IN THE LUBRICATING OIL BOILING RANGE INTO A COKING CHAMBER OPERATED AT A PRESSURE OF ABOUT 10 TO 100 P.S.I.G., MAINTAINING SAID CHARGE THEREIN AT SAID ELEVATED TEMPERATURES FOR A PERIOD SUFFICIENT TO CONVERT SUBSTANTIAL AMOUNTS OF THE COMPONENTS THEREOF TO COKE WITH CONCOMITANT DISCHARGE THEREFROM OF VAPOROUS THERMAL DECOMPOSITION PRODUCTS, SUBJECTING THE VAPOROUS THERMAL DECOMPOSITION PRODUCTS TO FRACTIONATION, AND WITHDRAWING FROM SAID FRACTIONATION A HIGHLY AROMATIC AND OLEFINIC DISTILLATE HEAVY COKER GAS OIL HAVING A LOWER BOILING RANGE THAN THE CHARGE TO THE COKING CHAMBER BUT WHICH BOILS IN THE LUBRICATING OIL DISTILLATION RANGE WITH APPROXIMATELY 90% BOILING ABOVE 550*F., SUBJECTING SAID HEAVY COKER GAS OIL FRACTION TO A SERIES OF REFINING STEPS INCLUDING THEREIN A SOLVENT EXTRACTION STEP AND A DEWAXING STEP ON THE RAFFINATE THEREFROM TO YIELD A LUBRICATING OIL AND A WAX PRODUCT.