US3291718A

US3291718A - Combination lube process

Info

Publication number: US3291718A
Application number: US440155A
Authority: US
Inventors: Frank A Biribauer; James D Bushnell; Harold N Weinberg
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1965-03-16
Filing date: 1965-03-16
Publication date: 1966-12-13
Anticipated expiration: 1983-12-13
Also published as: NL6603429A; FR1471150A; NL148098B; GB1111624A

Description

Dec. 13, 1966 F. A.B|R1BAUER ETAL 3,291,718

COMBINATION LUBE PROCESS Filed March 16, 1965 All NOZLLI Frank A. Brbouer domes D. Bushnen Horokj N. Wemberq nvenrors United States Patent O "ice 3,291,718 COMBINATION LUBE PROCESS Frank A. Biribauer, Cranford, .lames D. Bushnell, Berkley Heights, and Harold N. Weinberg, East Brunswick, NJ., assignors to Esso Research and Engineering Company, a corporation of Delaware Filed Mar. 16, 1965, Ser. No. 440,155 17 Claims. (Cl. 208-36) This invention is directed to an improvement in the manufacture of lubricating oils. More particularly, the invention teaches a process whereby paraflinic and naphthenic lubes may be produced from non-naphthenic crudes while substantially increasing lube yield per barrel of crude over that obtained in conventional processing. This is accomplished by utilizing a unique sequence of residuum treating in conjunction with an unexpected synergistic extraction effect of treating an atmospheric residuum in a combination tower and a heart-cut ltower.

Two types of crude oil are normally utilized in the manufacture of lubes. Parainic crudes are generally used in the production of high quality motor oils, aviation and turbine oils. This type of crude includes fraction which have a relatively high viscosity index which can be substantially increased by treating. The other crude type,

naphthenic crude is used to make large volumes of lubes in which the viscosity index is not of great importance. The outstanding feature of these crudes is that they make lubricants which have especially desirable properties in certain heavy duty engines such as .the diesel engine.

It is well known in the art to treat feed oils, particularly distillate feed oils, with various solvents in order to separate the relatively more aromatic type constituents having low V.I. from the relatively more parainic type constituents having high Vl. extraction solvents generally employed are phenol, various cresols, furfural, sulfur dioxide and the like. In these operations the feed oil is usually contacted with the selected solvent such as phenol, either in a countercurrent treating operation or in a multistage batch operation under temperature and pressure conditions to secure phase separation. As a matter of practice, the oil to be treated is usually introduced into one end of a countercurrent treating zone while the solvent or solvent mixture is introduced at the other end. The solvent and oil ow countercurrently under temperature and pressure conditions whereby phase separation is secured. The solvent rich or solvent extract phase is Withdrawn from one end of the countercurrent treating zone, while the solvent poor or the raffinate phase, comprising the more paraiiinic type constituents, is withdrawn from the other end of the treating zone. The respective streams are then handled in a manner to separate the solvent from the oil. It is further known to those skilled in the art to conduct a light hydrocarbon deasphalting process. In such a process, an oil phase or feed stream containing asphaltic type constituents is mixed with a light hydrocarbon solvent such as, for example, liquid propane, under temperature and pressure conditions whereby the asphaltic type constituents are precipitated. After separation of the asphaltic type constituents from the deasphalted oil, the respective streams are handled in well known manners to recover the solvent.

Waxy constituents are also removed from paratiinic type oils in order to improve the quality of the oil itself. This improvement in quality is represented by a deduction 3,291,718 Patented Dec. 13, 1966 of the cloud and pour point of the oil. This is accomplished by well known methods which employ a dewaxing solvent such as propane, methyl ethyl ketone or similar product. In operations of this type, the waxy oil and the solvent are usually heated to a temperature to secure a single phase or substantially complete miscibility of the ingredients. The waxy mixture is then chilled in order to precipitate wax particles or crystals from the solution. The chilled mass is filtered in order to segregate the wax particles and further handled in a manner to recover the dewaxed solvent.

These processes and others like them in which the various steps are combined, have represented a substantial step forward in the art. However, several serious drawbacks do exist with the processes which are currently in use. First, naphthenic lubes can only be made from naphthenic type crudes. Second, the yield of high V.I. paraflinics for the best quality motor and `aviation oils is not as high as is desirable. By viscosity index is meant the relative measure of the difference in viscosity at F. and 210 F. A high viscosity index means a small change in viscosity with temperature which is desirable in a motor oil. In general, removal of aromatic type compounds by extraction improves the viscosity index. According to this invention these problems have now been solved by making use of unexpected synergistic effect found in a combination lube process. Naphthenic and paraflinic lubricating oils are prepared from an amospheric residuum by introducing the residuum into a combination treating zone. A solvent having -a preferential selectivity for aromatic type constituents as compared to parainic type constituents is introduced into the upper region of this combination zone. A deasphalting solvent is introduced into the lower area of the combination zone. A deasphalted raflinate phase is removed from the top region of a combination zone. This raffinate is then passed to a heart-cut tower z'one. A solvent having a vpreferential selectivity for aromatic type constituents as pected synergistic effect which has been discovered and paraflinic as well as naphthenic lubes are produced from non-naphtheniccrudes. In addition, yields are increased.

The first process unit in the combination lube process is a vacuum flash tower where feed which is usually an atmospheric residuum is introduced. Steam stripping is used to effect efficient fractionation to reject light endsnot required for lube manufacture. The stripped residuum is then cooled before enteringi the combination tower. The feed enters at a temperatu-re of about 100 F. to 150 F. Feed entry may be at many different points along the wall -of the tower but it is preferred to introduce the feed close to the center of the tower, propane or another suitable deasphalting agent such as butane, pentane or ethane enters the bottom of the tower at a temperature of about 100 F. to 150 F. The propane acts as an asphalt precipitator. Phenol or furfural nitrobenzene dichlorated ether, phenol, cresol mixtures enters the top of the tower and performs an extraction of low viscosity index, poor color, highly aromatic components from the feed. The, rainate phase from the combination tower is typically 40 vto 60% of the feed. This ratiinate phase includes a high V.I. oil containing the majority of the treat propane from the combination tower and some dissolved phenol. The majority of the propane is then ashed in a drum at high temperatures and pressures. The bottoms from this drum contain the phenol and oil from the combination tower raiiinate and a small amount of propane. The extract phase leaving the combination tower contains the bulk of the phenol, the remainder of the propane, the precipitated asphalt, and the highly aromatic extracted oil. The extract phase is sent to a high pressure iiash drum where the bulk of the propane is recovered. The bottoms from this ilash drum contain the phenol, asphalt and extract.

The raiiinate phase oil and phenol mixture from the high pressure propane flash next enters a second extractor referred to hereinafter as the heart-cut extractor. Here, additional phenol is added to effect the separation of high V.I. parafiinic type oils and medium V.I. industrial type oils. The raiinate from the heart-cut extractor is then stripped yof all solvents in a solvent recovery tower. The phenol and propane are vaporized and the high quality oil is stripped with a volatile stripping gas, which may be propane, to completely recover all solvent. The raifinate oil is then sent to a vacuum rerun tower where products are cut todesired viscosity grades. Typically, light, intermediate, and heavy viscosity distillates and a residual bright stock are obtained in the paraiinic rerun tower. Steam stripping may be used on side streams for flash correction to remove any propane and high vapor pressure, low boiling components remaining in any of the side streams. The side streams are cooled and sent to intermediate tankage. The bottoms from the rerun tower are hydroned while hot to reduce Conradson carbon and to improve color and color stability. The hydroned bright stock is cooled and sent to intermediate tankage. Some or all of the distillates may also be hydroiined if required for product quality. The extract phase from the heart-cut extraction tower enters a solvent recovery tower similar to that used on the heart-cut rainate. The heart-cut extract contains 60 to 90% of the treat phenol and the oil yield is typically from 20 to 50% of the feed to the heart-cut extractor. This oil-phenol mixture is heated by exchange with hot rerun side streams and with condensing phenol.

The propane stripping gas is used in the bottom section of th'e solvent recovery tower to completely remove all phenol. The phenol stripped hot oil is then hydroined or treated in any desired manner such as caustic rerunning acid treating or clay treating as a .broad cut to irnprove the color and color stability of the naphthenic stocks. The hydroiined product then passes through a furnace where it is heated to a desired temperature before entering a vacuum rerun tower. Light, medium and heavy viscosity distillate stocks are cut from the naphthenic oil. A residual naphthenic bright stock may also be recovered if desired. Steam stripping is used in the bottom to effect efficient fractionation and provide reasonable yields of high viscosity material. These stocks pass through side stream strippers which steam strip out any entrained solvent and improve fractionation. Each side stream is then cooled by exchanging with the extract phenol mixture from the heart-cut tower. The side streams are then trim cooled to 160 F. to 200 F. before going to intermediate tankage. The bottoms from the naphthenic rerun tower is similarly cooled before going to tankage. The combination tower extract, approximately 50% of the feed, contains asphalt and highly aromatic distillate oil. The extract also contains 50 to 75 volume percent propane on oil and 50 to 90% of the treat phenol. This extract is heated and fiashed at 500 F. to 600 F. and 225 to 300 p.s.i.g. to remove the bulk of the propane, approximately 90%. The oil-propane phenol mixture is then heated in a furnace to vaporize the remainder of the solvent. The solvent-.free extract is stripped with propane stripping gas to completely recover the phenol. This stripped asphalt aromatic oil portion enters a vacuum stripper to remove the last traces of propane and phenol. This tower acts as an explosivity corrector. The propane and phenol streams from the heart-cut rafnate solvent recovery tower, the heart-cut extract solvent recovery tower and combination tower extract solvent recovery tower are combined and utilized as a source of high level heat. The condensing phenol and sensible heat available in this stream is utilized as preheat for each of the solvent recovery towers. The condensed phenol and propane are trim cooled before entering a phenol accumulator drum. This drum operates at 20 to 75 p.s.i.g. and 200 F. to 275 F. Vapor is withdrawn from the phenol accumulator which contains 5 to 15% phenol with the remained being propane on other light hydrocarbon solvent.v This stream is cooled to 115 F. to 125 F. to condense the remainder of the phenol and recover essentially phenol-free propane vapors. These propane vapors go to a propane compressor knockout drum where they are mixed with the chilled propane from the dewaxing plant. A common propane compressor is used to compress the stripping gas and vaporized combination tower treat propane and the chilled propane required for the dewaxing plant. These vapors are condensed at 150 F. to 125 F. and 250 to 275 p.s.i.g. The stripping gas required for the solvent recovery towers is withdrawn at an intermediate stage of the propane compressor. Makeup propane required for combo tower treat is removed from the propane accumulator. Dewaxing plant propane is also withdrawn from this drum. The paraiinic and naphthenic lubes are dewaxed in block loperation. Each stock is individually dewaxed in a propane dewaxing plant. The parainic stocks have a yield of 75 to 70% dewaxed oil and the naphthenic stocks have a yield of to 95% dewaxed oil. The pour point of the finished products decreases with decreasing yield and may be varied from 0 F. to 30 F. in the dewaxing plant. The dewaxed stocks are sent to product tankage and serve as base stocks for iinished motor oils and industrial oils. The combination lube plant provides broad cut continuous processing of an atmospheric residuum of a variety of viscosities and qualities.

The iigure is a schematic view of a preferred embodiment of the instant invention.

Turning toy the figure an atmospheric residuum containing the full range of lubricating oils from light distillate to bright stock, which is a residuum from .a typical Mid-East crude is introduced through line 1 into tower 2.

Atmospheric bottoms may be used directly if the residuum length is suitable. However, stripping is often required to remove light material which is not required for lube manufacture. These light materials are typically boiling below 650 F. Tower 2 is a stripping tower which operates under vacuum. The tower would .be operated at a pressure of to 300 mm. Hg .and a temperature of 650 F. to 750 F. Overhead products are removed through line 3. This accounts for about 10 LV percent of the total residuum introduced into the stripping tower. The stripout may be returned as distillate to the fuel side of a refinery or utilized as fuel for the plant of the instant invention.

The bottoms from the stripping tower 2 are removed through line 4 and fed to combination tower 5. The feedstock is introduced at approximately the middle of the combination tower. Phenol is injected into the top region of the tower through line 6 at a temperature of F. to 200 F. and a treat feed rate of 50 to 150% on feed. Liquid propane is injected into the bottom of the tower 7 at a temperature of 120 F. to 200 F. and a treat rate of 300 to 500% on feed. Tower pressure is adjusted to maintain propane in the liquid phase, generally 300 to 500 p.s.i.g.

The overhead product from the combination tower removed through line 8 is a deasphalted raffnate phase consisting of the more parainic portion of the residuum, a

major portion of the solvent propane and a minor portion of the phenol. About 80 to 100% of the propane, about 30 to 40% of the phenol and about 40 to 60% of the more parainic portion of the residuum are passed overhead. The more paraiiinic portion of the residuum will typically have a V.I. in the range of 60 to 100. 'Ihe bottoms from the material treated within the combo tower 5 is an extract phase containing the more asphaltic and aromatic portion of the residuum, .a major portion of the phenol and a minor portion of the solvent propane. This material is sent to a solvent recovery facility through line 9 where the phenol and propane are recovered through line 11. An alternate possibility, although it is not shown in drawing, is the recovery of the solvent by heating and stripping. The asphaltic, aromatic portion of the residuum is a high viscosity, low V.I., low API gravity material. This is removed through line 12. It may be used as fuel or processed further to recover potentially byproducts such as highly aromatic specialty oils and asphalt.

The overhead material from the combo tower 5 is removed through line 8 and sent to solvent recovery facilities 13 where most of the propane is recovered through line 14 for reuse elsewhere. The propane is recovered by heat flashing or any other suitable means. Phenol remains with the deasphalted raffinate oil and is removed through the bottom of recovery facilities 13 through line 15.

The deasphalted rainate oil phase, containing about 45 volume percent oil, 40 to 45% phenol and yabout 10 to 15% propane, is introduced at substantially the mid point of heart-cut tower 16. Heart-cut tower 16 is a tower designed to remove a select portion of a middle distillate. No intermediate tankage is required between combination tower 5 and heart-cut tower 16. The oil plus phenol stream is introduced to the heart-cut tower at a temperature range of 120 F. to 200 F. Phenol is introduced near the top of heart-cut tower 16 at a treat rate in the range of to 200%; this is based on the deasphalted rainate oil feed, and at a temperature of 120 F. to 200 The overhead from the heart-cut tower is removed through line 18. It is a rainate phase consisting of the highest V.I. components of the feed oil, a minor portion of the phenol and a small amount of residual propane from the combo tower S. The bottoms from the heartcut tower are removed through line l19. This is an extract phase consisting of medium and lower V.I. components of the feed oil. A maj-or portion of the phenol is also included as well as a small amount of propane. The higher V.I. raffinate portion of the feed oil which is subsequently processed to make parainic lubes is typically in the range of 90 to 105 V.I. The medium and lower V.I. extract portion of the feed oil, which is subsequently processed to make naphthenic lubes, is typically in the range of 30 to 80 V.I. It has unexpectedly been found that the small amount of propane in the feed to the heartcut extraction step is desirable. This desirability is for a variety of reasons. Initially, the propane reduces the viscosity of the phases, thus permitting easier settling in the extraction tower. However, a further and also unexpected result occurs in that the presence of propane favorably alters the solubility of relationships between phenol and oil, permitting a better quality oil to be made with less phenol treat and at lower temperature.

The high V.I. overhead from the heart-out ltower 16 is removed through line 18 from whence it is sent to solvent recovery facilities 20 where phenol and residual propane are removed for reuse. Their removal is effected through line 21. This represents all of the remaining phenol and propane. The solvent-free raffinate oil is removed from the bottom of tower 20 through line 22 from whence it is passed to vacuum fractionating column 23 for distillation into viscosity grades as required by the individual product slates. The temperature in the vacuum fractionating column 23 varies between 650 F. and

750 F., pressure within the column varies between 50 to 200 mm. Hg. Three distillate grades are removed from the column 23. A light grade is removed through line 24, a medium grade through 25 and a heavy grade through li-ne 26. It would be obvious to one skilled in the art that more =or fewer grades may be made depending on the product lube slate and/or requirements of the individual plant. If desired, the distillate grade may be stored in tan-kage and then sent to a dewaxing plant 27 in block operation.

Bottoms from the vacuum fractionating tower 23 is hydroiined in reactor 29. The bottoms are passed through line 28 into the hydroiiner 29. It is, of course, obvious that any` lube linishing apparatus may be utilized and that the hydroning apparatus -is merely convenient. Distillates may also be hydroiined if required for product quality. Typical lube hydroning conditions are utilized. These include a space Velocity of .2 through 2.0 volumes of liquid feed per volume of catalyst per hour, pressures of 500 to 1000 p.s.i.g., temperatures of 450 F. to 650 F. and treat gas rates of 200 to 2000 s.c.f./barrel of feed. Hydroning takes place over a cobalt molybdate catalyst. This hydroning treatment improves the color and color stability of the vacuum fractionating tower bottoms and reduces carbon residue. The hydrofined bright stock is stored in tankage and charged to the dewaxing unit 27,V

in blocked operation and then sent to finished lube base stock tankage. Dewaxing may be carried out in conventional fashion using ketone, propane urea, spray or any other suitable process.

Low to medium V.I. bottoms from the heart-cut tower 16 are passed through line 19 from whence they are sent to solvent recovery zone 31. Phenol is removed through line 32 .so that it may be reused. The solvent-free extract oil is removed through line 33 and sent to hydroner 34. Conditions within hydroner 34 are similar to those within hydroner 29. No intermediate tankage is required between the heart-cut tower and the hydroner. The hydroned extract oil is removed from the bottom of hydroiiner 34 through line 35 and sent to vacuum fractionating column 36. The vacuum fractionating column is maintained at a temperature of 650 F. to 750 F. and a pressure of 50 to 200 mm. Hg. Three distillate grades are made and they are recovered through

lines

37, 38 and 39. A light grade is recovered through line 37, a medium grade through line 318 and a heavy grade through line 39. Needless 4to say, more or fewer grades maybe recovered depending on the product lube slate. These are naphthenic base stocks. The lubes in

lines

37, 38 and 39 may be stored or sent directly to dewaxing zone 27. Dewaxing zone 27, as mentioned previously is any suitable dewaxing process. Desired naphthenic base stocks are then recovered through

lines

37', 38 and 39 after the dewaxing in zone 27.

The combo lube plant processing sequence described in the drawing may be altered to fit special circumstances. For example, it may be economical to place dewaxing upstream of rerunning which would reduce the number of intermediate tanks required and would make it possible to operate with only one rerun tower. A single rerun tower could be used, even in the preferred embodiment of the drawings, if appropriate tankage is provided upstream to block the parafiinic and naphthenic broad cuts through. These variations in sequence and equipment requirements are well within the scope of the combo lube process of the instant invention.

The combo lube plant processing conditions can be altered to make a variety of products from widely different crudes. Combo tower temperatures and solvent treats may be adjusted to handle a wide variety of crude residua and make raffinate suitable for processing to meet different lube product slates. For example, the typical effect of increasing combo tower temperature is to decrease rainate oil yield while improving viscosity index, carbon residue and color; or alternatively, to permit using lower phenol treats. Increasing phenol treat generally has similar effects to increasing tower temperature. When propane treatsy are increased, the eiect on ranate oil is usually to increase yield, to decrease carbon residue and viscosity index and to improve color.

TABLE I.-SAME COMBO TOWER TREATING CON- DITIONS HANDLE VVIDELY DIFFERENT CRUDES l 75% Aramco Canadon US.

25% Seco Coastal Safaniya Reduced Crude Feedr` Gravity, API. 13. 2 16. 5 20. 2 Viscosity, SSU/2t0 315 842 82 Conradson Carbon, Wt. Percent 12. 2 9. 8 2. 4 Combo Tower Conditions:

P ropane Treat, Vol. Percent 420 400 440 Phenol Treat, Vel. Percent 100 100 105 Ternp., F., Top/Bottom 145/125 145/125 125/110 Combo Tower Radinate:

Yield, Vol. Percent 52 60 85 VI (dewaxed) 91 80 59 Viscosity, SSU/210 69 108 67 Gravity, API 26. 4 26. 7 23. 4 Conradson Carbon. Wt. Percent 0. 7 0. 6 0. 5

The above table indicates the variety of crudes which this invention can treat. Parainic crudes such as Aramco/Safaniya, naphthenic crudes such as U.S. Coastal and mixed base crudes such as Canadon Seco may all Ibe successfully treated. Desirable results may be obtained by treating this variety of crudes as illustrated by the combo tower raiinate analysis. The yields of 52 volume percent, 60 volume percent and 85 volume percent are high. The V.I.s and lother characteristics of the raflinate are suitable for further processing in the heartcut tower to make high V.I. parainics and medium V.I. naphthenics.

Example An Aramco Safaniya atmospheric residuum which was 75% Aramco and 25%` Safaniya was introduced into a processing apparatus essentially as described in the -attached figure. About 1000 barrels were introduced into a combination tower. The -tower was maintained at a temperature of 125 F. to 145 F. and a pressure of 440 p.s.i.g. About 46,80 barrels of deasphalted rainate phase were withdrawn from the top of the tower. This included about 3900 of propane and about 280v of phenol. Most of the propane was removed in a solvent recovery facility and the rainate land phenol and residual propane were passed to a heart-cut tower. The temperature in the heart-cut tower was 145 F. to 150 F. and the pressure was 220 p.s.i.g. An overhead was recovered from the heart-cut tower, this consisted of -about 470 barrels of raiinate phase containing the rainate oil having a V.I. of 101. The bottoms from the heart-cut tower were an extract phase containing medium and lower V.I. components having a V.I. of 60. About 810 barrels of extract phase were recovered from the bottom of the tower. The overhead fraction was treated in a solvent recovery wherein phenol and residual propane were'removed. About 350 barrels of solvent-free ranate oil were then sent to a vacuum fractionating column wherein the temperature was 730 F. and the pressure was 63 mm. Hg. Three Idistillate grades of .paraiinic flubes were removed from this vacuum fraotionating column. They were 6 barrels of overhead discard, 45 barrels of low viscosity oil, 48 barrels of intermediate viscosity oil and 155 barrels of high viscosity oil. The bottoms from the vacuum fractionating column comprising 96 barrels were hydrofined at 625 F., S00 pair-g. and 500 s.c.f. per barrel hydrogen treat rate. The bottoms from the heart-cut tower, consituting about S10 barrels were sent to a solvent recovery zone wherein propane and phenol were removed. The extract oil comprising 150 barrels was then sent to a hydroner. The temperature within the hydrotiner was 625 F., the pressure was 800 p.s.i.g. and the hydrogen treat rate was 500 s.c.f./bbl. The catalyst was cobalt molybdate. The hydroiined extract oil was then sent to a vacuum fractionatinlg column wherein the temperature Iwas 696 F. and the pressure 63 mm, Hg. Three streams of naphthenic crudes were removed from the vacuum fractionatinig column. There were 3 barrels of noverhead discard, 15 barrels of ,low viscosity oil, 35 barrels of medium viscosity oil and '77 barrels of high viscosity oil. All the streams, both paraiinic and naphfthenic, were then subjected lto propane dewaxing.

The combo lube process produces paratnc and naphthenic lu'bes from non-naphthenic crudes, maximizes lube yield per barrel of crude, provides considerable exibility to vary lube product distribution with product slate requirements and reduces lube plant costs compared with conventional processing.

Although this invention 4was described with some particularity, it is intended only to be limited by the attached claims.

What is claimed is:

1. In a process for the production of naph-thenic and paraiinic lubricating oils from a parafnic atmospheric residuurn which comprises introducing the said atmospheric residuum into a combination treating zone, introducing a solvent having a preferential selectivity for .aromatic-type constituents as compared to parainic-type constituents into the upper area of said combination zone, introducing a deasphalting solvent into the lower area of said combination zone, removing a deasphalted raftinate phase from the top region of the said combination zione, passing said raffnate to a heart-cut tower zone, introducing a solvent having a preferential selectivity for aromatic-type constituents -as compared to parainic-type constituents into the said heart-cut tower zone, withdrawing a rainate phase comprising paralinic-type constituents from the top of said heart-cut tower, withdrawing an extract phase comprising naphthenic-type constituents from the bottom region of said tower zone.

2. The process of claim 1 wherein said solvent having a preferential selectivity for aromatic-type constituents is Iphenol and said deasphalting solvent is propane.

3. The process ofclaim 2 wherein said combination zone is maintained at a temperature of F. to 200 F. and a pressure of 300 to 500 p.s.i.g., and the said heartcut zone is maintained at a pressure of 200 to 400 p.s.i.g. and a temperature of 120 F. to 200 F.

4. The process of claim 1 wherein said atmospheric residuum is a residuum from a paranic crude.

5. A process for the production of naphthenic and paranic crudes from a paralinic atmospheric residuum which comprises preashing hot atmospheric residuum to reject light ends, passing the light ends free residuum into a combination tower zone, introducing a solvent having a preferential selectivity for aromatic-type constituents as compared to paranic-type constituents into the upper -area of said tower zone, introducing a deasphalting solvent into the lower area of said tower zone, withdrawing an overhead fraction containing desired lube components, passing said overhead fraction to a heart-cut tower zone, recovering two fractions from the said heart-cut tower zone, an overhead fraction rich in paranic lube constituents and a bottoms fraction rich in naphthenic lube constituents, passing the loverhead fraction to a vacuum fractionating tower Iwherein it is separated into a plurality of streams, passing said plurality of streams to a dewaxing zone and recovering highquality parainic lube constituents, passing said bottoms fraction from heart-cut tower to a hydrotreatirrg zone, passing said hydrotreated fraction to a vacuum fractionation zione, whereby said fraction is divided into a plurality of naphthenic streams, passing said naphthenic streams to a dewaxing Zone and recovering a plurality of nafphthenic lube streams.

6. The process of claim 5 wherein said hydrotreater is maintained at a temperature of 500 F. to 650 F., a pressure of 500 to 1000 p.s.i.g. and a hydrogen treat rate of 200 to 1000 s.c.f.

7. The process of claim wherein the said solvent having a preferential ainity for aromatic-type constitutents is phenol and the said deasphalting solvent is propane.

8. The process of claim 5 wherein the said heart-cut tower is maintained at a temperature of 120 F. to 200 F. and a pressure of 200 to 400 p.s.i.g.

9. The process of claim 5 wherein the said combination tower is maintained at a temperature of 120 F. to 200 F. and a pressure of 300 to 5 00 p.s.i.g.

10. The process of claim 5 wherein the said overhead fraction from the sead heart-cut tower zone and the said bottom fraction from the said heart-cut tower zone are both subjected to solvent recovery before being treated further.

11. An improved process for producing both paraflinic and naphthenic lubes which comprise passing an atmospheric bottoms feed to a stripping zone wherein light components are removed, passing the bottoms from said stripping zone to a combination tower zone, passing phenol into the top region of the said tower zone, passing propane into the bottom region of said tower zone, removing a rainate from the top region of said tower zone, passing said raffinate to a solvent recovery zone wherein at least a portion of the said propane is removed, passing the said propane poor raflinite to a heart-cut tower zone, introducing phenol into the top region of said heart-cut tower zone, removing a paranic lube constituent from the top region of said tower Zone, removing a naphthenic-type lube constituent from the bottom region of said tower zone, passing said parainic constituent to a solvent recovery zone wherein at least a portion -of the phenol and at least a portion of the propane are removed, passing the said propane and phenol poor parafnic constituent into a vacuum fractionating zone from whence a plurality of streams are removed, passing said plurality of streams to a dewaxing zone from whence a plurality of high quality paranic streams are recovered, passing the said naphthenic constituent to a solvent recovery zone wherein at least a portion of the said phenol is removed, passing the said phenol poor naphthenic constituent to a hydrotreating zone, removing the hydrotreated naphthenic constituent and passing it to a vacuum fractionating column from whence a plurality of naphthenic streams are removed, passing the naphthenic streams into a dewaxing zone, withdrawing said plurality of high quality naphthenic streams from the dewaxing zone.

12. The process of claim 11 wherein the said hydrotreating takes place ove-r a cobalt-molybdate catalyst at a temperature of 500 F. to 650 F. and a pressure of 500 to 1000 p.s.i.g.

13. The process of claim 11 wherein the said atmospheric bottom feed is recovered from a pararlinic crude.

14. The process of claim 11 wherein the said dewaxing is propane deWaXing.

15. The process of claim 11 wherein vthe said combination tower is maintained at a temperature of F. to 200 F. and a pressure of 300 to 500 p.s.i.g.

16. The process of claim 11 wherein the said heart-cut tower is maintained at a temperature of 120 F. to 200 F. and a pressure of 200 to 400 p.s.i.g.

17. The process of Iclaim 11 wherein the said vacuum fractionating columns are maintained at a temperature of 650 F. to 750 F. and a pressure of 50 to 300 mm. Hg.

References Cited by the Examiner UNITED STATES PATENTS 2,095,972 10/ 1937 Faragher 208-314 2,168,875 18/1939 Noll 208--317 2,687,982 8/1954 Baumann 208-34 2,692,222 9/ 1954 Packie 208--34 2,764,529 9/ 1956 Leygonie et al 208-19 3,052,622 9/ 1962 Johnson et al 208-27 DELBERT E. GANTZ, Primary Examiner.

HERBERT LEVINE, Examiner.

Claims

1. IN A PROCESS FOR THE PRODUCTION OF NAPHTHENIC AND PARAFFINIC LUBRICATING OILS FROM A PARAFFINIC ATMOSPHERIC RESIDUUM WHICH COMPRISES INTRODUCING THE SAID ATMOSPHERIC RESIDUUM INTO A COMBINATION TREATING ZONE,INTRODUCING A SOLVENT HAVING A PREFERENTIAL SELECTIVITY FOR AROMATIC-TYPE CONSTITUENTS AS COMPARED TO PARAFFINIC-TYPE CONSTITUENTS INTO THE UPPER AREA OF SAID COMBINATION ZONE, INTRODUCING A DESPHALTING SOLVENT INTO THE LOWER AREA OF SAID COMBINATION ZONE,REMOVING A DESPHALTED RAFFINATE PHASE FROM THE TOP REGION OF THE SAID COMBINATION ZONE,PASSING SAID RAFFINATE TO A HEART-CUT TOWER ZONE,IN-