US1791052A - Heavy j - Google Patents

Description

Feb. 3, 1931. J. H. BREGI 1,791,052

TAR REFINING Filed Dec. ll. 1928 3 Sheets- Sheet l REF/NED PARAFF/N ATTORNEYS Feb. 3, 1931. J. H. BRI-:Gl 1,791,052

TAR REFINING Filed nec; 11,11928 s sheets-sheet 2 TAR Orga/rfc 5056s CRESTE W We] E@ jed/MJ lglllElORl ATTORNEYS Feb. 3, 1931. J H BREG, 1,791,052

' TAR REFINING @l @mi INVENTOR jawn/7d TTORNEYS Patented Feb. 3, 1931 -.UN1TED STATES PATENT ori-ica PETMLES, 0F PARIS, FRANCE, `A SOGIETE ANONYME 0F FRANCE TAR REFINING Application nled December 11, 1928. Serial No. 325,190.

10 constitutes a better yield from the raw ma `terialand to produce tar that constitutes a better yield from the raw material and con- -tains constituents of greater value than the constituents of tars heretofore produced, the

i5 art'of extracting from such tars the ma'ximum quantity of valuable products in a condition in which they ossess their maximum value has not been eveloped. Laboratory experimentsy have indicated the presence in such improved tars of some valuable products, but the methods of refining to which j these tars have been subjected have degraded or destroyed the valuable constituents thereof. so indicated to be present, and the value of the final products obtained by such methods has hardly 'been sufficient to warrantthe recovery ofsuch products as have been obtained from tars by former methods. For example such tars contain highly valuable high-viscosity lubricating constituents as well as less valuable lubricating constituents of lower viscosity and con- Atain amorphous Wax aswell as crystalline wax; but the former impossibility of removing such amorphous wax to an extent suiicient to produce low cold test lubricants of high viscocity, led to the practice of subjectin the tar to conditions that would convert allgof the wax present therein to crystalline form in order that it might be removed by the well-known ilter-pressing operations that are inapplicable to the removal of amorphous Wax. The result of this practice was that 'tar was subjected to destructive distillation in order to convert all of the wax present into crystalline wax to the end that it might be removed by known practice, and this operation degraded the lubricating constituents pres- -ent and only low viscosity lubricating oil of relatively low value was obtained. Great effort has beenmade `to convert suchllow viscosity lubricants so obtained into useful and valuable lubricants, as by subjecting such light lubricating products as the tar reneries were able to produce with a low enough cold test to polymerization and condensation under pressure or in the resence of catalysts, such` as metal chlorides, butl these efforts produced at best only inferior lubricants.

Moreover, the treatment applied to tar for the purpose of converting the contained wax into c stalline wax' in .order that its removal might possible, not only degraded the con- -stituents valuable as lubricants but reduced the wax contentand increased the pro Iortion of oils of low value, such as so-calle Diesel oils or burning oils, thus further reducing the value of the nal product.

In addition to the former inability to remove Wax from the lubricating constituents of .tar to a desired degree without reducing the proportion and impairing or destroying the value of the constituents of the tar, the

presence in tars of constituentsnot substan` tially found. in crude etroleum has prevented the obtainin of t e important constituents of tar in ull proportion and in valuable condition.v Thus, tars contain substantial quantities of resins, organic basic substances such as yridine and the like, and organic acid substances, such as phenols, which have industrial value when isolated, but which because of their have deterred or prevented skilled petroleum refiners from successfully refining tars by the application of the skill and knowledge of their callin Furthermore, the mere 'application of t e special operations, herein described, whereby the previously impossible dewaxing of tar products to 'a suicient degree is nevertheless successfully achieved with the production of low cold test products, do not produce satisfactory. dewaxed products from all tars.4 In other words and more particularly, it has previo'usl been impossible to de wax constituentso tar that contain lubricating oil of high viscosity, withoutde rading the lubricating oil content thereof, ut in accordance Vwith this invention it is possible to dewax such constituents satresence in tar A bricatm oils of var isfactorily without degrading the lubricating tars may be simply and economically obtained `in their valuable form with a minimum of loss and a minimum degradation of valuable products into the less valuable products. A specific object of this invention 1s to provide a process whereby a maximum quantity or proportion of lubricating oil of low cold test and of relatively high viscosity and substantially free of contaminating substances and substantially free of a tendency to oxidize or polymerize spontaneously is obtained from tars, particularly tars obtained by low temperature distillation from ligniteshale, coal, and the like', and especiall tars s'o obtained from lignite. A further eature of this invention is that there are produced in the practice thereof separate bodies of wax, one of which constitutes a high grade crystalline wax, and the other of which constitutesa high melting point hard amorphous wax. Also, in the practice of this invention resins present in the tar, and particularly resins that solidify s ontaneously presumably by oxidation or po ymerization, are obtained as a separate product, as are creosotes and or anic basic substances. In the practice of this invention the several products may be obtained in one or more parts having diferin characteristics. Thus the lubricatin o1l may come from the last treatment in a single body having medium viscosity and from which luviscosity may be produce1 or the lubncatmg oil may be produced in several parts having varying viscosity, and the creosotes may all be recovered to- Vto gether or may be recovered in parts having' varying viscosity. Other se arate prodlplcts` obtained in the practice of th1s invention. are naphtha, and burning oils, vresins and pitch.

lThe low cold test lubricatingxoil obtained by this process i's comparable in uality and yield to similar products obtaineil from petroleum, and it is obtained without any artiicial or synthetic treatments, and it maybe, divided, 'particularly b no-cracking distillation, into fractions avingA any desired properties, including so-called heavy cants such as cylinderstock.

'In the practice ofathisinvention variou specific modes of procedure may be followed, each.of which results in obtaining a maximum proportion of lubricating oil in substantially the condition in which it existed in the tar except that it has been' dewaxed to a desirable extent and freed of undesirable constituents' of the tar, and a maximum proportion of wax in substantially the condition in which it existed in the original tar except that it has been separated into a crystalline fraction and an amorphous fraction and is preferably freed of undesirable constituents of the tar. Thus, in the practice of this invention'there may be obtained from the tar by carefully performed non-destructive distillation, in which both. steam and vacuum may be employed to attain the desired end, a single fraction which alone contains, or two or more fractions which together contain, substantiall all of the wax of theoriginal tar in the orm in which it existed inthe tar and substantially all of the lubricatinv oil of the tar in substantially the form in willich it existed in the tar, such fraction or fractions being substantially free of resins. Also, in the practice. of this invention there are obtained one or more lubricatin -oil-containing fractions containing' Wax t at is as a whole sufiiciently crystalline to be removable by filter-pressing and one or more lubricating-oil-containing fractions ,containing wax that is as a whole not removable by filter-pressing and is substan- J5 jtions may be produced directly from the tar by careful distillation or a single fraction containing substantially all of the Wax and .substantially all of the lubricating oil and substantially free of resins may be produced. from the tar and then fractionated by careful distillation into'fractions containing only crystalline wax or only wax that is not removable by flterressing.

. An important eature or characteristic of this invention is that in preparation for dewaxing there are produced from the tar by careful distillation which vcauses a minimum of degradation of valuable products, one or more fractions containing only filter-pressible wax and one or more fractionsY contain# ing only non-pressible wax, said fractions together contalning substantially all of the v wax land all of thelubricating oil of the' ori inal tar in substantially the form in which they existed in the original tar except that said 'fractionsare substantially free of l resinsv although they may contain organic invention contains buta small proportion or tains wax and lubricating oil, or the last por- 1 3 tion or fraction of such a fractionj may be a residue; but if the tar contains a substantial quantity of such resins, as in the case' of tars obtained by low temperature distillation of lignite, itis an important feature of this invention that even the heaviest lubricatingoil-containindportion ofthe tar will be removed therelfrom by distillation and care will be exercised to prevent any substantial quantity of resins from distilling over into any distillate from which dewaxed lubricating oil is to be obtained. The' point'at which the cutis made to prevent resins from distilling over withv lubricatingvoil may be determined empirically. For example, the temperature at which the cut must be'"made Ato pievent resins from distilling over may b@ dark sludge-like substance which upon removal from the oil may be decomposed by l acid to free the creosote. In such treatment small quantities of resins may be removed -but it is preferable that the proportion of resins shall be as small as possible because,l

the presence of such resins promotes emulsication that impairs the separation from thc oil of phenolates, such as creosote salts.

, It is to be understood that in the combined y practice of several features of myinvention,

my invention is not limited to the removal of organic acid substances by caustic soda but includes removal thereof by extraction by means of solventssuch as alcohol'. l.

If organic acid substancesv are removed in the practice of my invention, by treatment Aso with caustic soda', the residual liquid remaining after the removal of the resulting precipitate, is Washed with Water; and that water is preferably added to the precipitate prior to decomposition `of the phenolates with acid for the recovery ofthe organic acid substance.

In the practice of this invention it is preferable that prior to the removal of organic acid substances, organic basic substances be A removed; and this can be accomplished by a mild acid treatment that separates out the organic basic substances inthe form of a sludge-like precipitate,

In the practice of my invention thexremoval of organic acid substances and organic basic substances may beefected priorto dewaxing subsequently to dewaxing. If they are removed prior to dewaxing they can be removed from separate fractions that contain wax and lubricatin oil .or theymay be re-',.

moved from a sing e fractionthat contains wax vand lubricating loil and is roduced either as a result of a single disti ation or by .bringing together a plurality of such fractions produced by distillation. If all of the material from which organic acid substances land organic basic substances are to be removed, exists or is brought into a single body,

`then that body must be divided before dewaxing into one or more fractions that contain only crystalline wax' and one or more fractions that contain only non-pressible wax.

If basic substances and organic acid substances are' removed in the practice of myinvention from dewaxed products obtained from tar, then the dewaxed products may be -brought together for that purpose or those substances may be removed from a separate body of oil dewaxed by filter-pressinr and from a separate body of oil produced by removal of amorphous Wax, or from several of cach `of such bodies.

In the practice of my invention the first of raw naphtha and burning oils and there will be produced one or more fractions containing only crystalline wax and one or more -fractions containing only non-pressible wax and those fractions may be produced directly .fractions obtained fromthe tar will consist by distillation of the tar or by combining separate distillates obtained from `the tar or byv dividing 'up a single distillate obtained from the tar or by dividing distillates and combining fractions of distillatcs, and such fractions characterized by their Wax content are subsequently' free of resins, and as above stated they may or may not be free of organic basic and organic acid substances.

In the practice of this invention the fraction or fractions containing crystalline Wax will be caused to bev sutliciently dilute either by carrying into them low boiling substances as a result of the distilling operations or by adding gas oil or naphtha, to permit of effecwith known 'methods, such filter-pressing preferably being performed in a plurality of stages carried out at successively lower temperatures.

i In vthe practice of this invention any crystive de'w'axing by filter-pressing in accordance talline wax that is contained in a fraction containing amorphous wax and which'can be removed therefrom by distillation, is removed by producing a distillate containing Wax in such form that the 'distillate may be added to the fractions that are to 'be filter-pressed, without impairing the dewaxing thereof. In the practice of this invention the fraction or fractions that contain amorphous wax, freed as far as possible of crystalline wax, are dewaxed by methods dependent upon difference of specific gravity between the wax andpol in spite of the previously existing diiliculty iss of dewaxing tar products unless the wax was converted to crystalline form in an operation that degraded the heavier lubricating oil. Thus, in the practice of this invention the fraction or fractions containing the amorphous Wax and containing heavylubricating oil stock are dewaxed by diluting the Waxcontaining oil with a solvent of such specific gravity and added in such proportion that subsequent chilling will produce a wax precipitate that is in s iich form that it may be removed by subsidence and, a residual liquid that is suciently heavier or lighter than all of the wax to permit such separation, and then removing the precipitated Wax either by gravity settling or by means ofa suitable centrifugal process and apparatus such as the process and apparatus described in Sharples atents No. 1,232,104; No. 1,351,265 and N o. 1,416,890 and No. 1,416,891. In the process and apparatus -described ,in those patents a carrier liquid is employed and that carrier liquid may be heated and fed to the bowl at a point near the Wax discharge orifice in accord'- ance `Vith Jones Patent No. 1,649,117. Obvlously variations and modifications may be made in the centrifugal separating operation employed in the practice of my invention. The products of this operation are heavy de; waxed lubricating oil and petrolatum, both of `which contain solvent which isJ removed b'y distillation before or after subsequent treatment.'

If the organic basic substances and organic acid substances are removed from the fractions subjected to dewaxing treatment, prior to the dewaxing thereof, the dewaxed product is ready for final treatment; but if de- Waxing is carried out. prior to removal of those substances then those esubstances are removedv from the deivaxed bodies of', oil

.as above described, either by removing those substances in the manner described from the separate dewaved fractions'orby vcombining the dewaxed bodies of oil and then removing those substances from them in the manner' described.

Regardless of which of the various fortgoing modes-of procedure is followed, the final treatment, after organicbasic and organic acid substances have been removed and after dewaxing has been vcarried ut, iyill be a decolorizing treatment and a dividing of the oil into bodies of oil having desired viscosity. The decolorizing may be' effected in any known manner, as by acid treatment or by clay treatment or by both of such treatments, and the decolorizing treatment may be applied to separate fractions or to a single 'body of oil produced by bringing together a number of dewaxed fractions freed of organic acid and basic substances. The final purified product is by non-cracking distillation freed of gas oil and it may thereby b e divided into a number of fractions of lubrlparticularly after sweating, is a good quality' paraflin Wax of high average melting point and of good color. The plienols may as above described be recovered in a single fraction that is thick and viscous or slightlypasty or may be recovered in several parts varying from parts that are distinctly liquid vto parts that are in the form of a firm paste.

In the practice of thisV invention lnost tars can be successfully refined by following a procedure in which there is obtained from the tar by careful non-destructive distillation, a single fraction containing substantially all of the Wax -and free of resins or a plurality o f fractions which together contains substantially all of the wax and are free of resins and then subjecting the product so removed from the tar to mild acid treatment and toistrong alkali .treatment and to appropriate deivaxing treat-ment, carrying out these treatments in any desired order except that just prior tothe dewaxing treatments the products so obtained from the tar must be brought into tivo bodies, one of which contains only crystalline Wax and will contain light and mediumoil and the other of. which contains only wax thatv cannot be removed 'by filter-pressing and vcan be removed as herein described and will contain heavy oil.A The treatment for the removal of organic bases and the treatment for the removal of organic acid substances can be appliedl to all of the products so obtained from the tar While those products exist in a single body or to separate parts of such products, the removal of organic bases prior to the removal of organic acid substances being preferable. However, variations in the tar to be refined may require slight modifications of the foregoing procedure Within the spirit of this invention, and it may be necessary to carry -out the separate steps in a particular order to the end that the best results Will be obtained.

From the foregoin it will be apparent that in accor'dance wlth this invention the valuable products of tars are obtained without substantial loss or degradation as products of high value and possessing their valuable characteristics, the products being free of undesirable impurities and particularly impurities likely to change the character of the oil spontaneously. It will also be apparent that lubricating oils of almost any desired viscosity are obtained from tar simply and economically with a minimum of distillation steps as contrasted with previous recovery of only a small amount of" nonviscous lubricating oil and a reduced amount of wax, the lack of quantity and value of productsformerly recovered being due to an 4intense cracking distillation not carried out by me but performed for the purpose of converting all wax to crystalline form in order to eiie'ct its removal.

At this point I describe a. specific example of the practice of my invention, with the understanding that the illustrative practice of my invention so described is set forth merely to assist in the understanding of the general principles thereof and that my invention is not limited to the details so described.

Thus, in the application of my invention to 2o the refining of tar obtained by low temperature distillation (400 C.- to 600 C.) of an average German lignite, the tar, having a specificgravity of 0.948, was distilled to a residue of hard pitch in such manner as tov avoid so far as possible decomposition due to heat and to carry the constituents of the tar into the distillates in practically the same form and state in which they existed in the tar. In this distillation the first cut was crude naphtha constituting 0.2% of the tar and having .07 59 specific gravity and a boiling range of C. to 160 C. After this cut the introduction of superheated steam to the still was begun and the amount of steam was gradually increased until the end of the distillation.

The next cut consisted of crude kerosene er light Diesel ou constituting 17.34% of the tar and having 0.925 specific gravity and 16% creosote index.

The next cut consisted of gas oil containing some crystalline wax and constituting 17.74% of the tar and having a specific gravity of 0.935, a creosote index of 22.5% and a iiashpoint of 115 C.

After this cut was completed a vacuum of about 690 mm. was maintained in the still.

The next cut consisted of light wax distillate containing crystalline wax and con- 'Ihe next cut consisted of heavy wax distillate containing amorphous wax incapable of removal by filter-pressing. This fraction constituted 29.05% of the tar and had 0.948

i specific gravity, 11.5% creosote index, 197 C.'

iiashpoint, 5.67 Engler viscosity at 50 C., and A45 C. cold test.

The next cut consisted of resins and gum-g. my material constit11ting.5.06% of the tar,`

which could have been left in the residue but which are advantageously kept separate from the lubricating oil` fractions.

of 60 C.' to 70 C. which reduced a viscous stituting 24.91% of the tar' andliaving 0.934

The residue consisted of hard pitch constituting 2.85% of the tar and having 81-82 Kraemer Sarnow melting point.

It is possible lthat'during the distillation of the light wax distillate a rise and fall of specific gravity of the stream may occur. Inasmuch as the flashpoint and viscosity rise regularly through such eriod it is improbable that such unexpected changes of gravity are due to occurrence of crackin and the decrease of creosote index throug suchperiod indicates that the ychange of specilic gravity is duc to change of creosote content. A similar explanation applies tothe occurrence of higher speciiic gravity at the end of the gas oil cut than at the beginning of the light wax distillate.

The advantages of this invention are best obtained when sharp cuts are made between the several fractions. A sharpcut is particularly important between the heavy wax `distillate and the resins which may be taken oil as a distillate or retained in the residue. An eiicient dephlegmator is recommended. The point at which this cut is made may be determined empirically with each batch or type of tar treated, by determining what percent of the tar must be left in the still at theend of the heavy wax distillate. The heavy wax distillate should contain substantially no resins and the temperature at the end of the cut can be determined by experiment as above described. .0 The gas-oil fraction and the li ht wax distlllate were combined and treate with about 2% byv weight of 50 B. sulphuric acid which se arated out a sludge that included combine organic bases such as pyridine, the loss being about 1.92%.

The heavy wax distillate was similarly acid treated with a loss of 0.73%. v

The acid treated fractions were then separately treated with about 5% -by weight of 38 B. caustic soda solutionat a temperature dark sludge precipitate. e supernatant oil was washed in each case with a volume of water enlalO to 30% to 40% -of the oil, the last was water bein free of reddish color.-

This treatment carrie ou't`15.9% 'tif the light 115 distillate `and 13.1% of the heavy distillate..

'The sodium salts were decomposed by acid producing vlscous liquid creosotes from ther light ,distillate and gummy creosotes solid at ordinary temperature from the heavy distillate. The treatment changed the viscosity oi the heavy distillate from 5.67 Engler at 50 C. to 4.16 at 50 C. because of the removal of the hea creosotes.

In the i ustrative example here described the wax in the hea distillate appeared more crystalline after the alkali treatment, and by steam distillation with a maximum tempera-- vture of 340 C. there was removed and added tothe light wax distillate a fraction having 13o filter-pressing and contained valuable viscous ing and 54 C. after sweating.

lubricating oils and was substantially free of creosotes, resins, and asphalt. )Vhile the existence of such oils in tar may have been proved by acetone extraction in a laboratory experiment, these oils were destroyed by the previously practiced operations that converted this amorphous wax to crystalline wax,

the inability to remove the amorphous Wax having led to the practice of such operations. However, in accordance with this invention viscous oils containing this wax which cannot be removed by filter-pressing can be successfully dewaxed on a commercial scale centrifugally. Thus, the stock containing wax incapable of removal -by filter-pressing was blended with naphtha to produce a mixture comprising 30% by weight of oil` and 70% of naphtha, the mixture was slowly chilled at the rate of 1 C. to 11/2 C. per hour during 44 hours down to 25 C. The chilled mixture was then introduced into a Sharples centrifuge substantially of the type` shown in Fig. 4 of Jones Patent No. 1,649,117, hot carrier liquid being employed. After distilling off the naphtha from the dewaxed oil solution discharged from the centrifuge, the product consisted of dark cylinder stock havingl a specific gravity of about unity, 3.48 En vler viscosity at 100,.-232 C. flashpoint, 27 2. rcpoint, -2 C. cold test. This dewaxed oil represented 54.25% of the heavy amorphous stock prior to dewaxing and 7.55% of the original tar, a yield comparable to that obtained from good average crude petroleum. The balance of the heavy amorphous dewaxing stock was petrolatum-having a melting point of 54 C. and representing 6.07% of the original tar, this being a hard amorphous wax, it may be refined and used commercially.

Crystalline wax stock comprising gas oil, the light wax distillate, and the distillate .taken from the original amorphous fraction and constituting 44.48% of the original tar, was dewaxed by filter-pressing in two stages at respectively 16 C. and 5 C. The paraffin obtained comprised 23.78% ofthe stock dewaxed or 10.58% of the original tar, had a melting point of 48-49 C. before sweat- The sweat oils were available for re-cycling. The oil obtained by removal of crystalline wax and containing gas oil had 0.945 specific gravity, 130 C. flashpoint, 1.64 Engler viscosity at `inal tar and having made.

50 C., 4 C. cold test. This light dewaxed oil stock was mixed with the heavy dewaxed oil stock and the final dewaxed lubricating oil stock was refined with about 5% of 66 Be.

sulphuric acid with a loss of 7.8% of the tions.

(1) A gas oil fraction constituting 21.11% of the dewaXed stock and 8.27% of the 4orig- 0.904 specific gravity, 106 C. flashpoint, 2 C. cold test. y,

(2) A spindle oil fraction constituting 25.3% of the dewaxed oil stock and 9.9% of the original tar and having 0.920 specific gravity, 150 C. flashpoint, 1.85 Engler viscosity at 20 C. and 1 C. cold test.

(3) A still residue containing thedecolorizing clay which was lremoved by filtration giving a finished viscous internal combustion motor oil, constituting 53.5% of the dewaxed stock and not less than 20% of the original tai and having 0.970 specific gravity, 218 C. (open cup) flashpoint, 245 C. fire-point, 8.1 Engler viscosity at v50" C., 1.7 Engler viscosity atv 100o C., 0 C. cold test, '0.12% organicacidity expressed in S03, 0.11% ash, traces of soft asphalt, red in transmitted light, green in reflected light, traces only of crcosote, and free of hard asphalt.

The foregoing exemplary application of this invention indicates by illustration many conditions, causes, effects and results occurring in the practice of this` invention, but it is tobe understood that within the spirit of this invention many modifications may be Such modifications include the above described variations in the points at which the several treatments may be applied and the variations in the formation of separate lfractions. Also, the fraction containing amorphous wax may be a residue instead of a distillate, particularly when the tar is substantially free of resins. For example, some tars obtained from oil shale may be treated to produce a distillate containing crystalline wax and a residue containing amorphous wax above substantially all o a's a specificapplication of. this invention; i

Fig. 2 shows diagrammatically a flow sheet in which is indicated one of several possible modifications of the sequencev of operations embodying this invention; and

Fig. 3 shows diagrammatically a flow sheet in which is indicated another of the several possible modifications of the sequence of the operations embodying this invention.

W'hile I have shown ingthedrawings several possible modifications of operations embodyin this invention it is to be understood that still other .modifications may be made- 4Withinthe spirit of this invention. It seems preferable, in most cases, to remove organic aci'd substances prior to dewaxing when the dewaxing is to be carried out by continuons centrifugal. separation, cause those substances, particularly if they contain heavy creosotes, are likely toV interfere with continuous discharge ofthe wax from the centrifuge.

There is at present considerable scientific discussion concerning thevactual' form -or characteristics of wax. -However, Wax is called crystalline herein whenever it is of .suchL character that it can be removed by filterressing, and wax is called amorphous herein when it is of such character that it cannot be successfully removed by filter-pressing and can be removed by meth- -ods depending upon difference of specific gravity, althou h from a scientific point` of view socalled amorphous wax may consist of crystals of smaller size. In the claims, the expressions containing pressible wax andl containing amorphous Wax are used-in` the sense above described, although the tar fractions referred to may or may not contain organic basic and acid substances in addition to oil.

In the claims the expression carbonaceous solids is intended to include solids which may be composed wholly of carbonaceous material and also solids which include carbo-f naceous material but also contain, even in a large proportion, solid constituents which are not in themselves carbonaceous.

I claimt Y 1. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation sepas rating from the tar and from the resins and pitches thereof a mrt of the tar containing the lubricating-oil constituents of the tarand substantially free of resin and by similar distillation dividing that part of the tar so withdrawn into a fraction containing pressible wax'and a fraction con-v taining non-preible wax, and separately de'- waxin said fractions respectively by methods sritable to the removal of pressible wax` :and non-pressible wax.\

. 2. In the retiningof tarobtained by disn' till'ation of carbonaceous solids, the steps ing non -pressible wax, and separately dewax- 1n said fractions respectively by methods sultable to the removal of pressible wax'and non-pressible wax. v

3. In the refining of tar obtained by-ldistillation of carbonac'eous solids, the steps comprrslng by non-destructive distillation `separating from the tar and from the resins and pitches thereof a part of the tar containing substantially all of the lubricating-oil constituents of the tar and substantially free of resin and by similar distillation dividing that part of the tar sowithdrawn into a` fraction containing pressible Wax and a fraction containing non-pressible wax, separately dewaxingsaid fractions respectively by methods suitable to the removal of pressible wax and non-pressible wax, and removing from the part so separated from the tar organic acid substances and organic basic substances.

4. In the refining of tar obtained by distil lation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the 'tar and from the resins and pitches thereof a part of the tar containing substantially all of the Wax constituents of the tar and substantially free :of resin and by similar distillation dividing that part of the tar-so Withdrawn into a fraction containing pressible Wax and a fraction containing non-pressible wax, separately dewaxing said fractions respectively by methods suitable to the removal of pressible Wax andnonrpressiblewax, and removing from the part so separated from the ,tar organic acid substances and organic basic substances.

5. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from' the tar and from the resins and pitches thereof a fraction containing nonpressible centrifugally-removable wax and substantially free of resins, diluting said fraction with a solvent added in such prosubstantially free offresins, diluting said fraction witha solvent adde'din such propor- 'tion and of such specific gravity that upon chilling of the mixture there will be formed a discontinuous Wax precipitate and a residual liquid solution having a specific gravity-that. differs in thesame respect from the specific gravity of-all of the `Wax, chilling said mixture and thereby precipitating Wax therein, continuously separating precipitated wax centrifugally from said chilled mixtureJ removing organic basic and acid substances from said fraction, and therebg producing high viscosity low cold-test lu ricating Aoil from the tar. p

7 In the refining of tar obtained by distillation of c'arbonaceus solids, the steps comprisingby non-destructive distillation separating from the tar and from the resins and pitches thereof a fraction containing pressible wax and a fraction containing amorphous Wax and substantially free of resins, and in any order removing organic acid substances from that part of the tar constituted by said fractions and Useparately dewaxing said fractions respectively by methods suitable to the removal of pressible wax Aand amorphous wax.

y x8. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the tar and from'the resins and pitches thereof a fraction containing pressible Wax and a fraction containing amorphous wax and substantially free of resins, and in any order removing organic basic substances from that part of the tar constituted by said fractions and separtely dewaxing said fractions respectively by methods suitable to the removal of pressible wax and amorphous wax. f

9. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the tar and from the resins and pitches thereof a .fraction containing pressible Wax and a fraction containing amorphous Wax and ,substantially free of resins, and in any order removing organic basic substances and organic acid substances from that part of the tar constituted by said '3 fractions and separately dewaxing said fractions respectively by methods suitable to the removal of pressible wax and amorphous Wax. l 10. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the tar and from the resins and pitches thereof afraction containing pressible Waxand a' fraction containing amorphous wax and substantially free of resins, subjecting that part ofthe tar constituted by said fractions to mild acid treatment to remove organic basic substances, and

separately dewaxing said fractions respectively by methods suitable to the removal of pressible wax and amorphous wax.

11. In the refining of tar obtained by distil- 12. In the refining of tar obtained by disv tillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the tar and from the resins and pitches thereof a fraction containing .pressible wax and a fraction containing amorphous wax and substantially free o resins, removing organic acid substances from that part of the tar constituted by said fractions, and separately dewaxing the fractions freed of organic acid substances, respectively by methods suitable to the removal of pressible wax and amorphous wax.

413. In the refining of tar obtained by distillation vof carbonaceous solids, the steps' comprising by non-destructive, distillation separating from the tar and from the resins and itches thereof a fraction containing pressible wax and a fraction containing amorphous wax 'and substantially free of resins, removing organic acid and basic substances from that part of the tar constituted by said fractions, and separately dewaxing c said fractions freed of said substances, re-

spectivel by methods suitable to the removal of pressi le wax and amorphous wax.

14. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructivev distillation` separating from the tar and from the resins and aitches thereof a fraction containing pressible Wax and a fraction containing Y amorphous Wax and substantially vfree of resins, dewaxing the first fraction by filter pressing, dewaxing the second fractionby subsidence, combining anddecolorizing the` resulting dewaxed bodies of oi1',and fracobtain lubricating oil. y

15.. In the refining of tar obtained by distillation of carbonaceousv solids, by non-de?" structive distillation separating. from. the tar and from the resins and itches thereof a fraction containing centri ugally removable wax, removing organic b .ses from said fractionating the combined dewaxed product to l.

- specific gravity that amorphous wax and viscous lubricating oiland lsubstantially free of resin, removing organic acid substances and organic basic substances from said fraction, diluting and chilling andv centrifugally dewaxing said fraction.

17. In the refining of tar derived from lignite l by low temperature distillation, the steps comprising by non-destructive distilla- .tion separating from the tar and from the resins and pitches thereof, a fraction comprising amorphous wax and viscous lubricatmg oil and substantially freeof resin, subjecting said fraction to mild acid treatment and to alkali treatment, and then diluting and chilling and centrifugallydewaxing said fraction. f

18. In the refining of tarobtained by distillation of carbonaceous solids, the steps comprising by non-destructive distillation separating from the tar and from the resins and itches thereof a fraction that is substantlally free of resins and contains wax that is non-pressible and is removable b methods dependingupon difference of speci ic graviy, diluting -said fractionl with a solvent ad ed in such proportion and of such ugion chilling of the mixture there will be ormed a discontinuous wax precipitate and a residual liquid solution having a specific gravity that differs 1n the same respect from the s ecific gravity of all of the wax, chilling sai mixture and thereby precipitating wax therein, and separating precipitated wax from said chilled I mixture by difference of specific avity.

19. In the refining of tar obtained by distillation of carbonaceous solids, the steps comprising by non-destructive diistillation separating from the tar and from the resins and pitches thereof a. fraction that is substantially free of resins 'and contains wax that is non-pressible and is removable by methods depending upon difference of spep ciiic gravity, dilutlng said fraction with a solvent added in such proportion and of such specific gravity that upon r.chilling of the mixture there will be formed a discontinuous wax precipitate and a residualliquid solution having a specific gravitythat di'ers in the same respect from the specific gravity of all of the wax, chilling said mixture and therebvprecipitatingwax therein, separating precipitated wax from said chilled mixture y dlierence of specific gravity, removing organic basic andacid substances from said fraction, and thereby producing high viscosity low cold-test lubricating oil from thel tar. 20. In the refining of tar obtained by dis# tillation of carbonaceous solids, by non-destructive distillation separatinglfronl; the ftar es t ereo a and from the resins and pitc fraction containing non-pressible wax that is removable by difference of specific removing organic bases from said by mild acid treatment, then removing creosote from said fraction by alkali treatment, and dewaxing the fraction.

21. In the refining of tar derived from lignite by low temperature distillation, the steps comprising by non-destructive distillation separating from the tar and from the resins and pitches thereof, a fraction comprising amorphous wax and viscous lubricating oil and substantially free of resin, and in any order removing organic acid substances and organic basic substances from said fraction by any method suitable to the removal of amorphous wax and diluting and chilling and dewaxing said fraction by difl ference of specic gravity.

In testimony whereof, I have signed my name to this specification.

JEAN HBRGI.

gravity,

raction y lo cERTlrlca'rE or CORRECTION.

Prrerrruo. 1,791,0s2. Grarrred February `s, 1931,. ro

JEAN H. Basel.

' lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 37, for the misspelled word "viscocity'l read viscosity; page 2, line 58, for "no-cracking" read non-cracking; page 8, line `4l, claim 8, -for "separtely" read,` separately; same page, line 74, claim 11, strike out the word aud"; page 9, line 76, claim 20, after "fraction" insert the words by any method suitable to the removalof amorphous wax, and lines 86 and 87, claim 21, strike out the words "by any method suitable to the removal of amorphous wax"; and that the said'Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of April, A. D. 1931.

. M. I. Moore, (Seal) Acting Commissioner of Patents.

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