US2055210A - Process of producing lubricating oil - Google Patents

Description

Sept. 22, 1936. R, s VQSE 2,055,210

PROCESS 0F PRODUCING LUBRICA'I'ING OIL Sept. 22, 1936. R. s. vosE PROCESS OF PRODUCING LUBRIGATING OIL 3 Sheets-Sheet 2 Filed Aug. 2l, 1933 Sept. 22, 1936. R, 5 VOSE 2,055,210

PROCESS 0F PRODUCING LUBRICATING OIL ..Waented Sept. 22, g

UNITED STATE Richard S. Vose, Ridley Park, Pa., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Application ugust 21, 1933, Serial No. 685,994

11 Claims. t(Cl. 196-78) My invention relates to the treatment oi lubricating oils with metallic sodium with the object in mindof improvingv the qualities of the oil.4

While the process is applicable to the treatment of any lubricating oils, it is particularly applicable to the treatment of naphthenic base lubricating oil distillates for the purpose of effecting a substantial degree of dehydrogenation of the unsaturates, changing their temperature-viscosgg ity characteristics to approximate those of `a paraffine base distillate, and substantially improving their qualities in other respects. The process is also applicable to the treatment of petroleum, or petroleum residues, such as mazoot, containing M lubricating oil fractions in order to secure, as a product of a subsequent known lubricating oil distillation process, iinished lubricating oil distillates having the superior qualities and.changed characteristics abovebriey mentioned.

20 The use of metallic sodium for the purpose of improving the qualities of, and particularly for desulphurizing, gasoline is old and well known. The amount of sodium required for such purpose is so small as not to involve a prohibitive expense.

25 But it is impossible to treat lubricating oil with metallic sodium in an amount at all comparable with that required for the treatment of gasoline and secure any substantial improvement in the quality of the oil. It is known, however, to treat 30 naphthenic base lubricating oil with metallic sodium in much greater amounts and substantially improve some of its qualities, but the main objects of my invention, particularly dehydrogenaticn of unsaturates and change of temperature- 35 viscosity relationship to approximate that characteristic of paraihne base lubricating oils, have not been achieved.

My process for treating lubricating oil distillates, or oil containing lubricating oil fractions 40 before distillation `of the'lubricating oils, involves the use of a comparatively large amount of metallic sodium at a .temperature above its melting point. It requires, also, that the sodium shall form a `colloidal or quasi-colloidal suspension in 45 the oil to give a maximum ratio of contact surface to weights of sodium. My invention also involves a process for securing a nearly quantitative recovery of the sodium, without which the process is uneconomical.

50 Briefly, the present process consists in mixing oil with the proper amount of sodium, at a temperature above the melting point of a sodium, and then passing the oil-sodium mixture through a colloid mill. After passing through the colloid 55 mill, the oil which now contains the sodium in colloidal or quasi-colloidal form is passed through a heater wherein it is heated to the temperature at which it is desired to have the reaction take place. This temperature is usually in the neighborhood of 450 F. Within the reaction chamber the oil-sodium mixture is maintained in a constant state of agitation, the length of time for treatment being varied according to the type of oil being treated, and also according to the purity of the oil being treated. After the oil-sodium lo mixture has remained in the reaction chamber for a sulcient length of time to insure completion of the reaction, the mixture is drained from the chamber and passed either to a device for coagulating the unreacted sodium which is in colloidal 15 form or through a cooler and then to a lter press for separation of unreacted sodium and sludge produced from the oil. The sludge is then passed to a further stage in the process wherein the unreacted sodium may be removed therefrom, as will hereinafter be more completely described.

The sodium apparently acts as an inductor or promoter for the reaction rather than a catalyst. T he reaction is in the nature of a polymerization and/or dehydrogenation of the unsaturated portions of the oil, reducing them to a form in which they may be removed from the oil by illtration or other means. Certain sulphur compounds in the oil, and of course any water present, will react with a very small proportion of the sodium before the sodium begins its role as inductor or promoter. However, this phase of the treatment forms no part of the present invention, as the desulphurization and dehydration of oils by the use of very small amounts of sodium is old, as heretofore set forth. It is generally recognized that the degree of concentration of a catalyst in a reaction mixture does not affect the reaction and that inductors or promoters do affect a reaction mixture by their degree of concentration. Since, therefore, it has been observed that small amounts of sodium do not promote the desired reaction in the oil, it is believed that the conclusion above referred to is correct. namely, that the sodium, after it acts as a direct desulphurization or dehydration reagent, becomes a promoter or inductor for the dehydrogenation reaction.

It is necessary, in order to secure substantial dehydrogenation, that the sodium shall be in colloidal or quasi-colloidal suspension in the oil. It is also admissible, if not necessary, in order to secure the maximum desired dehydrogenation, to use not less than from 170 to 220 grams of sodium per liter of oil, dependent on the oil being treated. It is also necessary to use thisminimum proportion of sodium if it be desired to ref cover anything approaching a quantitative recovery of sodium. As the quantity of sodium is reduced, the. proportion possible to recover is reduced, Metallic sodium Abeing comparatively ex' pensive, as compared, for example, with reagents such as sodium hydroxide, its recovery is essential to an economical practice of the process. For

v to carry out the reaction at temperatures above the melting point of the alloylor. amalgam, and to reduce the alloy or amalgam to colloidal or quasi-colloidal form.v VIt is of course known that ammonia when in combination with sodium acts as a'metal, the combination being, to all intents and purposes, an alloy. Where, in the claims, metallic vsodium is specied as the promoting agent, I mean to include, as equivalents, substances such as those above specified,` which, when admixed in colloidal condition with oil, act In substantially the same way to effect the same results.

A better understanding of the invention may be had by reference to the accompanying'drawings illustrative of different apparatuses for carrying out-my process.

Fig. 1 is a diagrammatic flow sheet of apparatus'for treating oil with an excess of molten metallic sodium and recovering unused sodium.

Fig. 2 is a diagrammatic flow sheet of an apparatus for treating oil with an excess of molten sodium, and recovering thek excess sodium byl means of'liquid ammonia; and

Fig. 3 is a diagrammatic owsheet of an apparatus for treating oil with sodium ammonium and recovering the unreacted sodium by means of liquid ammonia. y

Referring now to Fig. 1: The numeral I0 designates a storage vessel or tank for the oil to be treated. The oil is removed through line II, and forced by means of pump I2 through heater I3 tocolloid mill I4. Before entering the colloid' mill, there is added, to the oil stream in pipe II, a predetermined amount of molten sodium from line I5, which is in communication with a molten sodium storage vessel I6. On passing through the colloid mill, the sodium and oil are thoroughly mixed, and the ymolten sodium is rey ducedv to an extremely finely divided condition.

Leading from the colloid mill I4 is line I1, in

which is `placed heater I3 for heating the oilsodium mixture. This line .I1 leads to an agitator I9 having therein a motor driven centrifugal agitating member 20. There may be provided three or more agitators such as I9 in order, if

desired, to make the process a continuous one.

The centrifugal vagitating member 2D is rotated at an extremely high speed of the order of 9,600 R... P. M: `'I'he agitating member itself consists of a dischaving a number of radial passages therethrough, anda downwardly extending portion having a passage therethrough which communicates with the radial passages in the disc.

-By rotating the agitating member at high speeds,

. the oil-sodium mixture is drawn in through the downwardly extending portion and is .expelled through the radial passages by the centrifugal force created by the high rotative speed. 'I'he agitator I9 isv provided with suitable heating means' not shown, to maintain the oil-sodium mixture at reaction temperature during its entire time of treatment. Any .suitable heating means, may be used, suchas electrical resistance heaters or heating coils employing steam or hot oil.

It is practicable, inplace of the specic agitator described, to employ agitators of other types commonly used in the treatment of oils. .Indeed it may be possible, afterthe passage through the colloid'mill, to dispense with agitation, since agitation is not required to maintain the sodium in suspension'in the oil. Agitation, however, is desirable, if not required. to maintain the entire body of oil at a substantially uniform temperature.

'From the bottom fof the agitator I9 a valved line 2l leads to a towerz 22.l The treated mixtureofoil, sludge and unreacted sodium is forced by means of pumpj23 in line-Minto the tower 22. This tower'. 22 containsv packing material 23, whichmay be iron Rashig" or Lessing rings, lling the tower "im'approximately two-thirds of its capacity; --.'1 The oil, containing sludge and some sodium,

`line 24, containing pump 25, and cooling coils 26, to a filterpress 21. "I'here may be provided a number of presses in order that the process may be carried on continuously. Line 28 containing'pump 29 leads from a lter press 21 to storage tank 30 for finished oil. 'I'he sludge, together with the finely divided sodium, forms fllter cakes on the filtering media within the press 21.

Leading from the top of tower 22 is a line 3I for the removal of hydrogen which vis formed during the treating step and is adsorbed by the sodium.

From a point below the top of tower 22 there extends a line 33 containing pump 34 for drawing off vmetallic sodium which is separated in the tower and accumulates to the level ofV line 33. This metallic sodium is passed to a washing tank l35, wherein it is. mixed with naphtha entering through line 36. The mixture of naphtha and sodium is withdrawn from the top of the washing apparatus through line 31 containing pump 38. The naphtha-sodium mixture is thus pumped to aA settling chamber 39, wherein the sodium is settled from the naphtha and is pumped out through line 40 by means of pump 4I and returned to sodiumstorage receptacle I6. The naphtha is removed from near the top of settling tank 39 through line 36 and is returned by means of pump 42 through line 36 to washing apparatus 35.

Lines 50 and 43 lead from the tops of tanks 35 and 39 respectively, to line 3I for the removal of hydrogen which is separated in washing tank 50 and settling tank 39.

The sludge and sodium which accumulate as filter cakes in press 21 are placed in ball mill 44, or in some other suitable grinding apparatus, and therein admixed with molten sodiumadmitted through line 53. After being thoroughly ground with molten sodium, the mixture is passed through line 45 by means of pump 46, and is forced through lter press 41. 'I'he filtering media in press 41 is of a type which will be wetted by metallic sodium and will therefore permit the free coalesced metallic sodium to pass through, but will hold back the sludge, which collects on such filtering medium as a filter cake. The so `point of metallic sodium (207 FJ, and is then passed through line I leadingl to the colloid mill. Line I5, as heretofore explained, conveysmolten 'metallic' sodium from the storage receptacle I6 to the colloid mill. The sodium and oil are so proportioned that the charge entering colloid mill Il is 70 pounds of sodium to 1 barrel of oil (equivalent to approximately 200 grams of sodiumto 1 liter of oil). In passing through the colloid mill the sodium is reduced to an extremely ilnely divided state and thoroughly admixed with the oil. The oil-sodium mixture leaving the co1- loid mill is then passed through heater I8 wherein it is heated to a temperature within the range of 400450 F. Enough oil-sodium mixture is fed to the agitator I9 to iill it to approximately two-thirds of its total capacity. `Due to the high rotative speed of the agitating member 20, the

oil-sodium mixture is maintained in a state of agitation insuring equal temperature conditions throughout the whole mixture. The oil-sodium mixture is maintained inthe highly agitated condition for a period of time ranging from half an hour to thirty-six hours, depending upon the type of oil being treated and the resistance to oxidation or change in temperature-viscosityA relationship desired.

Exactly what chemical change Atakes place in the oil is not known, as the sludge which is recovered has so far resisted all attempts at analysis. However, it has been determined that both dehydrogenation land probably hydrogenation are effected by the sodium treatment. That dehydrogenation is effected is shown by the presence of adsorbed hydrogen in the unreacted sodium. That hydrogenation is effected may be inferred by the change in temperature-viscosity characteristics and the change in specific gravity. The

presence of free hydrogen in an adsorbed condition in the unreacted sodium present in the sludge was rst detected when analyzing the sludge to determine the amount of sodium which had been reacted. This analysis was carried out by adding alcohol to a weighed sample and `determining the amount of hydrogen evolved. Since the amounts of hydrogen evolved were greater than the equivalent of the amount of sodium which was known to be present, it was apparent that free hydrogen must be present. -This was also conclusively demonstrated when the sludge was later treated with a further excess of molten sodium, and then washed with naphtha. Since no chemical change was apparent in the naphtha or in the`sodium,

and'since free hydrogen 'was evolved, there can be no Vdoubt that a dehydrogenation of the original oil tookl place in the agitator. Since the temperature-viscosity characteristics andthe gravity ofthe oil were also changed, it was evident that dehydrogenation and possibly hydrogenation of the orignal oil had been eiected. It is well known that" naphthenic base oils havera'temperatureviscosity slope diiering from the temperatureviscosity slope of parafdnbase oils, and when .the temperature-viscosity slopes of the untreated and the treated oils were'compared, it was found that the treated oil `more nearly -approximated the temperature-viscosity slope of a paraiiln base oil. This fact, coupled with the change in spe.- cinc gravity, corresponding to increase in the percentage of hydrogen in the oil, leaves no doubt as to the occurrence of dehydrogenation and possibly hydrogenation. It is, of course, evident that if unsaturated components ot the original oil are dehydrogenated by the action ot the sodium and the dehydrogenated components are removed as sludge, the remaining components of the oil will `be substantially saturated. It is also evident that the sodium treatment may dehydrogenate aportion of the unsaturates and hydrogenate the remaining unsaturates. There is concrete evidence of the dehydrogenation and removal of unsaturates but no irrefutable evidence of hydrogenation of a portion of the unsaturates.

The treated oil, containing unreacted sodium and sludge, is drained from the agitator I3 and pumped into the top of packed tower 23, which contains, in addition to the packing, fresh molten sodium. The entering mixture may be considered as an oil-sodium emulsion with the oil in `the external continuous phase. Obviously, with such an emulsion, the coalescence of the sodium particles is impossible until the phase is changed and the sodium becomes the external continuous phase, or interlacing phase. 'I'his changeis accomplished by flowing the oil, sludge and sodium mixture downwardly through the tower 22 which contains Raschig or Lessing ring packing and metallic sodium. In flowing down through the tower, the oil sodium emulsion changes phase and the sodium in the emulsion becomes the external phase,'due to the action of the large' bath of sodium in the tower, which coalesces the nely divided sodium that mixes with the sodium conor 18 per cent of the unreacted sodium will be recovered in the tower 22. When refining some light oils, the oil-sodium mixture may have a specic gravity less than that of the molten sodium at the temperature existant in tower 22. In such case the oil-sludge mixture would be admitted tothe bottom of tower 22 and owed upwardly through the sodium. The sodium i'ree oilsludge mixture would then be withdrawn from tower 22 near the top thereof and the excess sodium at a point below that at which the oil sludge mixture is withdrawn.

The oil-sludge mixture, still containing a small proportion of unreacted sodium, is passed from the bottom of the tower through cooling coils 26 to the filter press 21. Due to the coalescenc'e in the tower of the nely divided sodium present in the oil-sludge mixture, the amount of free sodium in the tower is increased, the excess being drawn off through line 33 and passed to the washing chamber 35.

In some cases it may be desired to eliminate thesodium recovery step in tower 22, in which case the oil-sodium mixture from agitator I9 will be passed directly to pump 25, cooler 26, and press 21 by by-pass 56 shown in dotted lines.

As hereinbefore explained, the oil sludge mixture after being cooled in coils 26 to a tempera- 'ture approximating 70 F., is passed through the stituting the bath. In practice, all but about 1'1 c thereonare' placed in ball mill 44, and

K performed therein.

with molten metallic sodium. When this grinding is complete, the sludge-.sodium mixture is subjected to further pressing in iilter press 41. This operation results in the removal oi' all unreacted sodium from the sludge. 'I'he i'ree sodium is then partly recycled to the grinding operation in mill 44, and partly pumped lto washing tank 35. l

'I'he washingand settling operations remove from the sodium the hydrogenwhich has been adsorbed therein. In the washing step, carried out in tank 35,'a small amount of hydrogen may be released, which is from time to time vented through line 55 to line 3 I'. The naphtha used `for washing the sodium to remove"Y adsorbed hydrogen is circulated continuously through the tanks 35 to 39, and is unchanged by the operations The sodium is removed from settling tank 39 and is pumped to sodium storage tank I6. Sodium, to make up ior that lost in the reaction, is added to storage tank I3 and may be added in the molten state through line f V'It is to beunderstood that any low boiling metal may be used to `dissolve the unreacted colloidal sodium, or mercury may be used to form a sodium yamalgam which can be readilyremoved from the treated oil or sludge. Such metals as potassium, calcium, barium, tin and lead may be used to coalesce the colloidal sodium and would be f equivalent to sodium used for the same purpose.

, condition.

In all steps from its admission with the oil to the colloidmill to the final removal of all unreacted sodium, except in the step of separating the oil, the sodium is maintainedl in a molten that vwhich is recovered, there is provided, preferably in line 43, a heating apparatus 52, to which heat may besupplid, preferably by means of superheated steam circulated through the coil therein, although mineral oil may be used as the heat transmitting medium. Since the melting .point of sodiumis below the boiling point of water,

- I the handling of molten metallic sodium presents f 55 no diiilculties whatever. It is, of course, understood thatv all sodiumecarrying lines should bein- I sulated. b J `The apparatus diagrammatically illustrated in Fig. 2 for the treatment and primary separation yof unreacted sodium is substantially the same as y that shown in Fig. 1.

` The method :for eifecting sodium recovery from the sludge, however, is' diil'erent in that liquid ammonia isl used, necessitating diieren.. apparatus. In Fig. 2 the oil to be treated is contained lin tank ||0 and is removed through line III and pumped by means of pump I|2 through heater I I3 wherein it is heated to a temperature somewhat above the melting point of sodium... The' sodium is stored in a molten condition in tank I I6, and is fed by means of pump II1 in line |I5 to colloid mill |I4, together with the heated oil. The oil-sodium mixk ture then passes through v line I I3 containing heater I I 9.'in which the mixture is heated to sub- The temperature in agitator I9 is substantially 450 F. The heated mixture is then passed to the agitator |20, which is similar to agitator I 3 oi Fig. l. Fromthe Vagitator |20 the oil and sludge is passed through cooler |2I- and therein cooled to approximately 70 F. This mixture is then forced by means of pump |22 through filter press |23.` The treated oil emerging from this lter press ispassed through line |24 by means of pump |25 to treated oil storagel tank |23. The tllter cake removed from press I 23 is placed in ball mill |21 yand is therein agitated with anhydrous liquid ammonia. 'Ihis mixture is then pumped through line |21 by means of pump |29 to filter press |30. From the lter press |30 is removed what may be said to be a solution o1' sodium ammoniumk in liquidV ammonia. vAfter filter cakes have been built up in press |30, the ltering media, together with such cakes, which are sodium free, are removed. The sodium ammonium solution removed from the lter press |30 is passed through line |3| to evaporator |32.

`Placed inline |3| is an expansion valve |33. This permits the expansion and evaporation of the ammonia, and causes the sodium ammonium to be deposited in the bottom of the evaporatorin a solid, but lmore or less nely divided state, the evaporator being maintained at a temperature approximating -27 F. The ammonia in gas form is removed from the top of evaporator |32 by line |34 and is compressed by compressor |35 and passed to Vcondenser |36. This condenser, by removing the heat of compression, restores the ammonia to its liquid form. The liquid ammonia passes from the condenser to an ammonia storage receptacle |31, from which it is drawn for feeding to ball mill |21.V It is, of course, understood that ball mill I 21 and press 30 must be maintained under suilicient pressure to keep the ammonia in a liquid state. The sodium ammonium collecting in the bottom of evaporator |32v is removed from time to time to a heater |38, to. which heat may be supplied by superheated steam coils. Within the heater |38 the remaining ammonia is driven oi and the sodium is restored'to its elemental state. The sodium is melted and flows out through line I 39 and is passed by .pump |40 to sodium storage receptacle I I5. The ammonia liberated in heater |33 is passed, by lines |42 and |34 to the compressor and condenser '|35 and |36.

Sodium storage receptacle ||6 may also be provided with steamrcoils I4| or other heating meansv for maintaining the sodium in a molten condition.

Evaporator |32 is showncombine'd with heater I38,the evaporator having a funnel shaped bottom portion, having a valve or valves therein for permitting the collected sodium to pass from time to time into heater |33. This, however, is not necessary, as the sodium ammonium may beremoved and transported to a heater separate from the evaporator.

'I'he apparatus diagrammatically illustrated in Fig. 3 is for the treatment of oil with sodium ammonium instead of with metallic sodium alone, and for the subsequent recovery of unreacted sodiumfrom the sludge. 2I0-designates an oil supply tank from which oil is drawn for processing. The oil is withdrawn from the tank through line 2|| by means of pump 2|2 and is passed through heater 2| 3 wherein it is heated to a Ytemperature approximating 450 F. From the heater2|3 the oil is passed -to a mixing chamber 2|4 having therein a motor driven stirring device 2I5. As

, the oil is admitted to mixer 214, sodium ammopump 220 to a reaction chamber 22|.

' means,

ammonium mixture in nium in granular form is also admitted from a storage receptacle for sodium ammonium, designated in the drawings as 2 I8. Due to the granular stateoi' the sodium ammonium, it cannot be pumped through a pipe line, but must be transferred to the mixing chamber `by mechanical such as a screw conveyer. grammatically illustrated in the drawings by dotted line 2| 1. When the sodium ammonium and oil are thoroughly mixed, they are passed to a colloid mill 2 Il, wherein the sodium ammonium is reduced to particles of colloidal size in intimate admixture with the oil. 'I'he mixture thus produced `is passed through line 2l9 by means of Thisagitator or reaction chamber contains a centrifugal stirring device 222 for maintaining the oil-sodium constant agitation and complete admixture.

Due to the eiiect of heat, a vapor pressure of ammonia will be generated Vin the agitating chamber 22 and the ammonia released from the mixture as gas will be drawn ofi through line 223 to compressing and condensing means, to be described hereinafter. The vapor pressure generated within theagitating chamber will by no mechanical means ings by numeral 23|.

means approach the vapor pressure of ammonia at treating temperature (450 F.) as the alloying of sodium with ammonia greatly changes the properties of the two components, lowering the tendency to generate high vapor pressures by the application of heat.

After the reaction iscompleted between the oil and sodi the mixture is.. passed by means of line 224 and pump 225 through a cooling coil 228, to a filter press 221 of any desired type. From the lter press the purified and nltered oil is passed to the storage receptacle 229 through line 228, by means of pump 230.

From time to reacted sodium and some sodium ammonium is removed in iilter cakes from the lter media in press 221 and is transported to a grinding device, which may be a ball mill, designated in the draw- Since the sludge is not in liquid form, it must be mechanically transported, such as by a screw conveyor, which is illustrated diagrammatically by dotted line 232.

In the grinding device 23| the sludge is thoroughly admixed with liquid ammonia fed through line 234 from a liquid ammonia storage vessel 233. When the admixture of sludge and liquid ammonia is complete and the sodium and sodium ammonium contained in the sludge are thoroughly dissolved in the ammonia, which is added in excess, the solution is forced through line 235 by means of pump 236 into a filter press 231. This filter press serves to hold back the sludge alone, and to permit the solution of sodium ammonium to pass out in a pure state to line 238. The sludge time to time from the filtering media in the filter press and' is transported by diagrammatcally illustrated by dotted line 233 to a place of disposal.

The sodium ammonium solution leaving press 231 is conveyed by line 238 to an evaporator 240 wherein the excess liquid ammonia is evaporated and passed oii through line 24|. This evaporating operation leaves the sodium ammonium in a granular state within the bottom of the evaporator.` From time to time this granular sodium ammonium is withdrawn and mechanically transported to the storage receptacle 2i6 by a screw is removed from time the sludge containing un` conveyor or other means, which is diagrammatically illustrated by dotted line 242.

The gaseous ammonia withdrawn from agitating vessel 22| and from evaporator 240 is' compressed by means oi compressor 243 and is cooled in condenser 244 to a temperature sufficiently low to liqulfy it. The liquid ammonia then passes through line 245 to storage receptacle 233.

It is apparent that the small proportion of sodium which is consumed by the reaction with various products in the oil must be replaced by fresh sodium. This is accomplished by passing sodium to a mixing device 246 through line 241, or merely by dumping lump sodium into the mixing device 243. At the same time, liquid ammonia is withdrawn from storage tank 233 and admitted by line 248 to mixing device 241. When the sodium is completely dissolved in the liquid ammonia, the solution is drawn off through line 243 and pumped by means of pump 250 through line 238 to evaporator 240. In the evaporator the excess liquid ammonia is evaporated in the same manammonium, a certain proportion of sodamide will be formed. This, however, does not disrupt the process, as the action of sodamide on oil is substantially the same as that of sodium ammonium, or metallic sodium itself. It is, however, preferable to remove the sodamide from the process from time to time. This formation of sodamide does not cause any monetary loss, as there is always a market for the same.

The amount of sodium ammonium which must be added to the oil should, of course, be greater than the usual 'l0 pounds per barrel of oil treated, as the weight of ammonia must be taken into consideration, so that there is always present at least 70 pounds of sodium per barrel of oil treated. As already stated, the temperature of treatment is 450 F. The oil sludge mixture after treatment is cooled to 7 5 F. in cooler 226 and is then filtered. The sludge is then ground with liquid'ammonia in the diagrammatically illustrated grinding apparatus 23|, at a temperature of 27 F. At this temperature there is a vapor pressure of only one pound gauge so that the operation may be carried out without the necessity of using expensive pressure equipment. The solution of sodium ammonium containing sludge is then passed through iilter press 231 at the temperature of 27 F., and the pure solution which has been freed of sludge is passed to evaporator 240. This evaporator is maintained at any pressure desired, the controlling factor being the rate of evaporation desired, and therefore the temperature at which it is desired to evaporate the excess liquid ammonia. It is, of course, understood that the evaporator 240 must be built to stand the vapor pressure of ammonia. at the temperature at which the evaporation is to be carried out.

The treatment of oil with pure metallic sodium is preferred to the treatment of oil with sodium directedto procedure for treating oil with sodium by abatch process.' It is to be understood. however, that any one of the three treating and recovering 'methods hereinbefore described may be carried out 'in a continuous. manner. For instance, oil and sodium in the proper proportions may becharged to agitatorl, (Fig. 1) and the mixture agitated until a. sample of the oil upon,v

withdrawal shows that it has reached the degree oi' purity or dehydrozenation desired. When the oil has reached such a state, fresh oil-sodium mixtureis continuously charged to the agitator I0 at 'P a slow rate and treated oil-'sludge mixture is-continuously withdrawn` from the agitatorl at the same rate that the untreated oi lsodium\m1xture vis charged. The treated oil-sludge mixture is then continuously passed through the tower 22 to coalesce most oi the sodium contained in the sludge, and the largely sodium-free mixture is withdrawn from tower'22 .and passed through filter press 21. There will, of course, be provided a number of illter presses such as presses 21 and 41, and also several grinding devices, such as ball mill 44, in Aorder that the il recovery' of sodium from sludge Vmay be continuous.. l. r

The steps Just described will also be applicable to the process as shown in Figs. 2 and 3.

yNumerous variations of the present process are possible without departing from the spirit and scope of the present invention. For instance.vthe oil treated may be a distilled lubricating fraction which has or has not been acid treated or subjected to other refining processes such as SO2 treatment, or contact clay treatment, or the oil treated may b e a residual lubricating oil which has or has not been subjected to the usual rening steps. The third modiication,and probablyv the most desirable, is the treatment of va reduced crude by the present process before distilling into the various desired lubricating fractions. If it is desired to treat a reduced crude, the fractions including all or light gas oil and all lighter frac' tions Vare removed by overhead distillation in any knownmanner, and the reduced crude or mazoot is treated as hereinbefore described by the addition of an excess of metallic sodium to the mazoot. The mixture is then subjected to the heating and reclaiming steps herein described. It has been stated that this modication vis probably the most desirable, since the treating time is greatly lowered. For instance, with some impure lubricating oil fractions, the time of reaction may be as high as 36 hours,` but when vtreating a mazoot with sodium, the reaction time vis cut to one-half an hour. v

Where, in the claims, I specify mineral oil lubricating oils, I means to include mineral oil, such as reduced crude (which may or may not contain lighter fractions than lubricating oil fractions) but before distillation into lubricating oil distillates, and also mineral oil which consists wholly of a lubricating oil distillate or distillates.

The following specic examples will serve to better illustrate the present process. The following oils, (A, B, C, and D) are all naphthenic base lubricating oil distillates which have not been chemically treated. They are, however, considerably better than the usual distillates before treatment, as they were produced without cracking. 'I'hese oils were produced by the process described in Pew Patent 1,761,153, to Arthur E. Pew, Jr., dated June 3', v1930.

v y 3,655,210 The operations so far'described have all -been ou A anun" sessie. Ane

Nahost- Nati'eet Nahost- Na treatins im .im

v '1o.1 f 23. a

400 805 400 455 533 -449 m9 170 26;: 1 0 -15 16m -lw Good Good 140 '05 0.05l "0. 08 Tm ma, Neutral Neutral d10-MWF. 40 hours 250 F. 75% 15g o on'tlo" Temp. of treatment F,.-. 420-440 Time oi ti'eatmel1i:-hou1's m Temperature oi illtraiion- F. 70 Oil used-grams m40 Reagent used-,grams 732 Grams nl Naperliter oioil 244 Pounds of Na per barrel oi oi1.-- 85. 4, Yield oi nil 82.5 Yield oi "polymer" '17.5 a

v Before After Characteristics oi the oil te .mamas Gravity-A. r. I 1a a 1 Flash-Cleveland open cup F.--. 450 22.30 Fim 515 4510 Vis. Baybolt Univ. at F..- 2390 13M Vis..Saybo1t Univ. at 130 F. 072 401 Vis. Saybolt Univ. at 210 F. 8a Color-N. P. A Pour test-A. S T M F Demulsiblity Emulsibility Conradson carbon-percent- Ash unna,... sligh Mmmm. 4g 1 0, 0v Sulphur-percent. 0. 35 0. 02

Tem ot treatment-JE... 30-440 Timgof treatment-Hours 4 m Temp. of illtrationF.--- 70 Qjlused d 3l00grams (3mm.)

use Grams of Na per liter oioil-'.. 709 mgl? Pounds oi Na per barrel ol oil--. 74.6 Yield oi reilned oil-. 75,7% Yield o( polymer (by diilerenee) 24,3%

characteristics of um ou Bm!" AM' mlining Gravity-LA. P. I 5 Flash-Cleveland open cup xlsi'm 2201i; Fire 005 Vis. B. U. at 100F 6113 22% Vis. S. U. at F. 1515 745 Vis. S. U. at 210 F. 152 l09 Color-N. P. A -SM 1% Pour test-A. S. T M +25 F. +5 F. yDemulsibility 180 1020 Emulsibility 2 oc. Culi Good Conradson carbon 0.89% 0.12% Ash Trace Trace "l Neutral Neutral Six h nr" J 05. 6 0.0 Bu phur 0. 45% 0. 11%

The following example will serve to show the results obtained when a. mazoot r toppedcrude. which has been freed ci gas oil and all lighter fractions. is treated by the present process.

ou IIE),

Na-Mazoot ratio-grams per liter 200 Na-Mazoot ratio-pounds per barrel- 70 Temperature ot treatment-"IB 450 Time of treatment-hours 1 1 Agitation Centrifugal Temperature of ltration F '10 Yield 0f Na-treated mazoot from original mazoot 65 Vac. distillation for lube. oil-mm 2 Yield 0f zero Slighroxidation lube. oil n i n from treated mazoot-per cent...... 100 Yield of zero sligh oxidation lube. oil

from original mazoot-per cent--- 65 Yield of zero sligh oxidation tube. 0il

from crude 47 Per cent Na consumed 1.5 Na consumed per barrel of original mazout-pounds per barrel 1.1 fNa consumed per barrel 0i treated mazout-'pounds per barrel 11/2 Na consumed per barrel of zero sligh oxidation lube. oil obtainedpounds per barrel lVz Untreated mazoot required per barrel of lube. oil obtained-gallons.. 65

The mazoot s0 treated was then subjected to a vacuum distillation to separate the various lubricating fractions.

Analysts by vacuum distillation Mazoot represents '72.35% of a representative mixture of Gulf Coastal type crudes.

The following example will show the treatment of oil with sodium ammonium:

ou UF" Temp. oi tment- Time ol treatment Agitation Temp. oi filtration.--

Characteristics 0i the oil Original Treated Gravitoy A. P. L m3 m8 Flash F 450 435 515 510 2390 1664 072 5m +0 s3 3% 5 C0 n carbon 0. 22 0. 12 Ash Trace Sli oxidation 48. 1 8. 7 S phur percent 0. 35 0.02

After separating the oil from the sludge by filtration, the sludge was ground with liquid ammonia and subsequently filtered to separate the ammonia-sodium solution from the sludge, and the excess ammonia then evaporated from the solution. This resulted in 100% recovery of unreacted sodium from the sludge.

ou G

Initial charge (200 gr./

liter) 678 grams sodium Temp. of treatment 425-450 F. Time of initial treatment 13% hours Gravity -c 19.0

D Flash 285 F' Rate of continuous treatment Fire -T 33 F- 011 4.5 ce/mmute Viscosity at 100 F 1047 Na 1 0 grams/minute Viscosity at 210 F 74 Ema? 5 2 grams/minute Pour test 10F. Sulphur 046% Consumption of Na dur- Chargel 1400 CC- ing treatment No appreciable amount Gravity 23.7 Neutral number Neutral Recovery of sodium Conradson carbon 0.19 1st step 82.1% of total sodium Ash-per cent Trace 2nd step 68.5% of remainder Sulphurper cent 0.09 Overall rec0very 94.4%

Temp. Vis.F. C0

mm. Percent .5.111. F. F. sligh color s E rement Nena. pres. chg. grav. dash re oxid. N.P.A. sulphur N0. g' vap Liq. 100 130 21o n 220 345 2 332 371 2 10 2&4 225 25o 41 30 0.0 1- 1s Neat. 0.02 310 415 2 10 214 275 305 5s as 0.0 1- 31 0.01 Neus. :101 404 450 2 1o 25.2 310 s55 0o 5s 0.o 1- s0 Neun. 002 42s 410 2 10 24.0 345 410 214 4a 0.0 1 41 Nant. a02 475 510 2 10 21.2 ses 450 312 49 0.0 1+ 91 0.01 Nm. 001 49s 542 2 10 22.4 420 400 ssa ea 0.0 1% Neus. 0.02 535 500 2 10 21.2 400 535 1,537 s1 a0 154+ Neue. 004 50o 570 2 10 221 505 570 151 104 0.o 2+ 0.05 Neat. aus 55a 715 1% 10 23.1 505 025 1.150 153 0.0 3+ Nant. d20 iig 21.7 035 73o 5,500 48o 0.0 Din-ed 0.00 Nant 1.15

Ash-trace Bttms{su1phura07} Temp. of recovery '1st stepn; 450 F. i 2nd step 250 F.' Yield o1' refined oil Average 80% .Sodium used-:for refining.. 'I0 pounds pervbarrel Afmixture of oil and sodium was treated in an agitator such as shown in Fig. 1 of the drawings.

'at 450 F.,.the' ratio of oil sodium being 200 gr.

Na per liter of oil ('10 pounds sodium per barrel of on), imtu .a sempre of the ou. on being withdrawn and ltered. showed a. zero sligh oxidation number. When oil having zero sligh oxidation characteristics was obtained, a continuousstream of untreated oil admixed with sodium in the same ratio as before stated was supplied to the agitator, and at the same time continuous rehaving canvas illtering media to separateV the refined oil` from sludge andthe remaining excess sodium. The pressed dry lter cake was then run into a mechanical mixer, in which it was ground with fresh molted sodium at a ,temperature of 250 F. After suilicientcontact in the grinding mill, the mixture was filtered through canvas 'andthe filter cake was pressed in a hydraulic press to remove -the excess sodium.

In the foregoing specific examples the sodiumoil ratios have been given in pounds per gallon or grams per liter. The following table shows the sodium-oil ratios on the basis of weight alone for the first six specific examples:

A. P. I. Den- G1.A Na per Percent Na Oil/Na gravity sity liter oil by weight ratio Percen 2l. l 927 200 2l- 5 4. 62/1 19. 7 936 200 2l. 3 4. 68/1 18. 3 945 244 25. 8 3. 87/1 18. 5 943 213 D. 5 4. 4211 19. 0 .940 200 2l. 2 4. 7/1 18. 3 945 185 19. 5 5. l/l

The gravities of lubricating oils vary between 17 and 35 A. P. I., it is therefore more convenient to express the oil-sodium ratios on the basis of weight alone and for this reason the following data is given to show the range of percentage of sodium possible where the oils are treated with 170 to. 220 cc. of sodium per liter of oil:

Percent Na bly weight of 170 gr'ams 220 grams per liter per liter Percent Percent A. P. I. Gravity oil 20 25. 9 17 A. P. I. Gravity oil 16. 6 23 What I claim and desire to protect by Letters Patent is:

1. The process of improving the viscosityamiamoy temperature characteristics and other qualities of mineral 'lubricating oils which comprises dehydrogenating unsaturated constituents of the oil Y by` subjecting the oil to the action of colloidally 2. The process of improving the viscositytemperature characteristics and other qualities of mineral lubricating oils which comprises subjecting the oil tothe action of collodially dispersed metallic sodium, at a temperature above the melting point of sodium but below the crack, ing temperature of the oil, until unsaturates are dehydrogenated and rendered substantially solidA at normal temperature and separable from the oil, utilizing in said procedure an amount of sodium in excess of that required. to effect said dehydrogenation and not less than about 16% to 26% by weight of the oil so as to enable it to be subsequently separated, separating the oil from the sodium and dehydrogenated unsaturates and separating the sodium from the dehydrogenated unsaturates.

3. The process of improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprises subjecting the oil to the action of colloidally dispersed metallicv sodium, at a temperature above the melting point of sodium, but below the cracking temperature of .the oil, until unsaturates are dehydrogenated and rendered substantially solid a t normaltemperature and separable from the oil, utilizing in said procedure an amount of sodium in excess of that required to effect said dehydrogenation and not less than about 16% to 26% by weight of the oil so as to enable it to be subsequently separated, separating the oil from the sodium and dehydrogenated unsaturates,'separating the sodium from the dehydrogenated unsaturates, treating the sodium with a washing iiuid adapted to separate adsorbed hydrogen therefrom, separating the sodium from the said washing fluid and utilizing the separated sodium, together with fresh sodium required to make up for that lost in the reaction, in the above specified treatment of fresh supplies of oil.

4. The process of improving the viscositytemperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium but below the cracking temperature of the oil, agitating the oil-sodium mixture until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, and removing hydrogen, sludge, and sodium from the oil.

5. The process of improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, passing `the oil-sodium-sludge mixture into contact with a solvent adapted to coalesce and selectively dissolve colloidal sodium, removing oil and sludge from the coalesced sodium, and then separating treated oil from the sludge.

6. The process of improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium. in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, passing the oil-sodium-sludge mixture into contact with a solvent adapted to coalesce and selectively dissolve a portion of the colloidal sodium, removing oil and sludge from the coalesced sodium, then separating treated oil from the sludge and removing further sodium from the sludge and utilizing the sodium separated as specied in the above dened treatment of fresh supplies of oil.

7. The process of improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting .mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point ofk sodium but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, passing the oil-sodium-sludge mixture into contact with a substantially larger amount of molten metallic sodium to coalesce a portion of the colloidal sodium, removing oil and sludge from the coalesced 65' sodium, then separating treated oil from the sludge and removing further sodium from the sludge by grinding it with liquid metallic sodium.

9. The process of, improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprise dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action oi colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium. but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, passing the oil-sodium-sludge mixture into contact with a substantially larger amount of molten metallic sodium to coalesce a portion of the colloidal sodium, removing oil and sludge from the coalesced sodium, then separating treated oil from the sludge and removing further sodium from the sludge by grinding it with liquid ammonia separating the liquid ammonia from the sodium and utilizing the separated sodium, together with fresh sodium required to make up for that lost in the reaction, in the above specied treatment of fresh supplies of oil.

10. The process of improving the viscosity-temperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil by subjecting the oil to the action of colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, removing hydrogen, sludge and sodium from the oil, and dissolving the sodium with sludge in liquid ammonia, then separating from the sludge the sodium ammonium so formed and hydrogen adsorbed by the sodium during the dehydrogenation reaction separating the ammonia and hydrogen from the sodium and utilizing the separated sodium, together with fresh sodium required to make up for that lost in the reaction, in the above speciiled treatment of fresh supplies of oil.

11. The process of. improving the viscositytemperature characteristics and other qualities of mineral lubricating oils which comprises dehydrogenating unsaturated constituents of the oil' by subjecting the oil to the action of colloidally dispersed metallic sodium, in an amount substantially in excess of that required to desulphurize and at a temperature above the melting point of sodium but below the cracking temperature of the oil, until unsaturates are dehydrogenated and rendered a sludge substantially solid at normal temperature and separable from the oil, passing RICHARD S. VOSE.

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