US1812924A - Process of making lubricating oil - Google Patents

Description

, July 7, 1931. w. T. BRYANT PROCESS OF MAKING LUBRIGATING OIL Filed Aug. 30, 1927 Patented July 7, 1931 'narran STATES PATENT OFFICE WILLIl-LM T. BRYANEOF I.|IO`'S'I[O1\T,y TEXAS, ASSIGITOR T0 W.- A. WILLIAMS, OF HOUSTON,

. .TEXAS PROCESS OFIv'IAKING LUBRICATING OIL Application filed August 30, 1927. Serial No. 216,497.

The present invention relates to a process of manufacturing lubricating oils, and has particular application to the production of oils suitable for lubrication from asphalt or naphthene base crudes. i

It is an object of the invention to utilize as much ofthe heavy fractions as possible, since it has been established that the socalled bottoms are highly valuable for lubricating oils.

To this end, the inventioncontemplates but a single complete distillation of the crude thereby materially lessening the apparatus employed andshortening-v the time of operation, both vas regards the production of the distillate and its subsequent chemical and mechanical treatment.

The generally accepted method of refining an asphalt or naphthene base crudefor the production of lubricating oils consists in distilling the crude and separating the desired fractions. The various lubricating fractions are then redistilled in order to obtain the desired flash and viscosity. The lubricating fractions obtained during the process of redistilling that do not have the desired flash and viscosity are collected and further refined by reducing or blending with other products. On the redistillation of the lubricating distillate the generally accepted practice is to add aV weak caustic solution to the lubricating distillate during the proc- *ess of the second distillation. After the lubricating distillate is redistilled and the desired fractions obtained, the product is then transferred to the agitator for chemical treatment. The chemical treatment consists of first agitatinfr the distillate with a fixed charge of 66 Be., sulphuric acid. The purpose of the weak acid treatment is 'to remove any water that is contained within the distillate. After the acid and the acid sludge produced from this treatment are removed, the charge is further .treated with a much stronger acid, -usually a powerful acid as a fuming sulphuric acid of substantially 98% concentration, and upon the removal of the acid sludge produced from this y treatment, the chargeis then transferred to .a wash agitatorrwhere the remaining acid and preferably the former. ,then passed to a wash agitator, and may, if desired, be treated with a weak caustic, and

held-by the distillate is neutralized with a weak caustic soda or a soda ash solution. After the excess caustic solution is removed, the distillate is transferred to a blow bright tank where the traces of moisture held by the distillate is removed by blowing with air.

This process is objectionable, because in the first distillation, a base of to 10% remains, which base is generally employed as fuel oil, and on redistillation of the lubricating distillate', it is necessary to leave a base of from 5 to 8% which is utilized also for fuel-purposes. Thus, anywhere from to of the crude and particularly thatpart possessing more valuable lubricating qualities is lost.

The figure is a fiow sheet illust-rating the process.

In this figure, A is the still wherein the crude oil is run, and where agitation with steam 4in the presence of caustic takes place. The gas oil and other fractions are drawn oflil and the remaining residue is distilled overhead and collected in the chamber C. From the chamber C, the residue is run into the reduction still B, where the oil is given the desired viscosity and flashpoint, and lighter fractions are removed. The dry distillate is then run into the chemical agitator F, whence it is subjected to acid treatment with either 66 B. or stronger usually The material is the excess caustic is removed and the chemically treated oil is passed to an air blower In some cases, the air blower I-I is not employed, and the oil is passed to a clay treating tank I, and thence to a filter J, from which the oil may be passed continuously to a vacuum apparatus to get out any remaining water. Y

With the present invention, I have found that the final product of my process is a lubricating oil of relatively light color possessing a distinct greenish fluorescence free from bluish tints, and furthermore, I do not iind it necessary to blend my product with a second distillate in order to secure the desired light color. My process is also i characterized by the fact that the unsaturated hydrocarbons can be removed Without interference With the cyclic or naphthene ring compounds, and my improved oil is particularly free fromhthe emulsifying constituents 'preventing any p'ossibility vef the emulsification occurring 'uri'rig treatment With chemicals. y a$result,of tests conducted with my product, it is found to be stable and highly resistantto heat, due to the fact that the lubricating oil is substantially free *from organic acids, resins, sulfo-acids, unsaturated hydrocarbons vvhi'clr-areeasily ii'zfif dized, gum Iand phenols Which are apparently cony tedjintoallaline,stable products ryi are o 'gie fareuueeroe `ehren I emp-roy, sedation are left Benina part or' ure as'e.

Aside trom-ure feet that I do not plateale 'al doiuuedistillation,e inverti- Vtion dut "in its `subsequent` 'ste meenemen 1th "materially expense' and tiere', and ehereeulfoeift fp o ld'in'ltlrquant yairdqualty drcate's ps of chemical less Inearryngeut die process, the Crude oil to se --aisunea Winoo may be any aes-a1 crude, is charged intol a` still and 'agitated as for eXar'ple, applying Ythe bottom thereofnas 4is Well known." D"i'i1'"-ing` taieagaeuoo, there le eee-lieu feo 'jure orio JvWea-l: 'caustic solution h is preferably 'gradually ira;ouuaed.v des may be employed one t 'conducted vvith My pref cev for employing a caustic suoli essor hydroxide fie the re-Sau of emmene wherein a eee"foorraueaeeuen Y bases 'as oeroude hydroxide, iiynjectedft'o distillation, Vwith agit-Mien l f the materiel are y pife'vii'o'usly, described are einlesen is eootafoea: anni an -oif the on 'hee been aieaueaovei teje-a with the fea'ee'ption-fepossi-blyof bottoms; o v- The small @enables the vprocess 'to heV carried et ure pro'oee's highly feaieieae errepercentage of bottomsl yis pumped from the still and utilized for fuel purposes. v

The entire lubricating fraction is collected and transferred to a tank or still for reducing the oill and obtaining the desired flash viscosity,

T'lie'reduction process :comprises heating the 'oilto remove the lighter fractions Which arevdistilled over head -until the remaining base or ycharge meets the desired test.

In this manner, no redistillaticn With consequent apparatus-extensive heat and loss of time is employed, and the flash and vis- `csity ofthe lubricating stock may be easily controlled. For example: a viscosity of 200 vflash of 325 Fahrenheit lcan be fobtaihfed tvith ve'r'y'lit'tlfe reduction; Un fur`- 'ther redti'ct'io'nf vvith tlf'r'eV percentage Y'of vthe K products distilled/off, it is' "pos's'ito 'obtain in 'this simple manner 'a base g for exemple-greater vvejeoeayjf ena M A fl sh tV a :considerable range, as reati-area. o l v lt'will be here noted that the `entire vbase not-tonly tvitlhit its iedi'sftiillation, aout also y without ire-eeen@ of blending. TVlYentliis' base' has been reduced 'to the sird viscosity "and"i'faslr,l lit is transferred to aleareafbie aviator roi chemical aoeuoefa. ,5 tthispint, it Ais thought vv'ell to 'explain that the caustic lrasldeen present in 'the oil all-'the operations 'prefvious'ly described, arid 'While possibly some of it may lijafe b'een'losttlis has been found not yto Wciably effect 'the operation of the .0f lighter. 'er

*easnof yfthe,presence of caustic in the rouaeea drainage', i no permitted oo employ *atveall lacid treatment and I prefer to treat the (distillate with `66 Be., sulphu'ric acid.

` sinformer,processes, an initial tn'ent tvith 66 Be., 4aeid isnecessar'y as a p I` nate this step since the distillate delivered toftlre 'agitator lchemjicalftaiil; ris *substantially dry. Y l Qlhille il erply 'preferably a Wealr acid 'treatiiifen' using va'sufliient iduaritity of acid dependentup'on ithe viscosity 'and quality of 'the distillate'being treated, I 'have in some L "cases -used stronG-rrV acid'of 98%. How fever, 'for mostpur @ses 4the Vweaker acid has been completely effective ingproducing an oil having the desired 'quality and color. v

After they distillate has been subjected to llt) withdrawn, iene "distillate is traae'lferreol to e jsuitobiejvasu agitar-or there die aard heid by the diedi-laters neutralized with freak solution or eaustie sode ash if le, "fourfdfaefefeeeary- Y j It, shout negocia-fedelta one 'reduced distinte produ'eed ,distillation "or the caust v'crude inayllfe incre treated in the 'agitator and 'wat ieee 'iirenuooa of eee emulsiication than is the case With processes heretofore employed. The excess caustic is then removed and r the distillate is transferred to a rather ,low

exchanger Where it is subjected to a temperature sufficient to raise the oil to a point Where it vvill react with, a decolorizing agent.

. The heated oil at such temperature is passed to a-mixing tank and a decolorizing clay is added While the mass is agitated and the reaction temperature'of the oil is sustained by means of heating elements arranged in the mixing tank. Since reaction takes place at once between the oil and clay, the oil may be immediately filtered so that the process is. very rapid and r'can be conducted with a"v minimum of complicated apparatus jand lWithout any loss of time.

The' filter is preferably of a type wherein the deposits can be flushed or sluiced from the chambers by means of Water, Without requiring dismantling of the iilteringapparatus. yThe employment of such a filter avoids the usual delays incidental to taking Vdown the apparatus to remove the cake and v then assembling. By using a filter from ,Which the cake is sluiced off by streamsof Water, my process is rendered so to speak continuous andv the time ofoperations is materially reduced. A small quantity of Water will pass through With the oil and since the oil is at a temperature aboveboiling, the Water content may beV easily removed by vacuum treatment.

As previously stated, application ofthe caustic solution to the crude prior to distillation, permits the useiof relatively Weak sulphuric acid inthe chemical treatment,

and Whereas Without the addition of this caustic, it Would be necessary to employa vmore powerfutacid as fuming sulphuric acid of substantially 98% concentration.

lVhen the distillate is treated withV G6'B.,

acid and subsequently clay treated, the desired greenish yiuorescence isvery pronounced While treatmentivith 98% acid or stronger, does not `result in so defini-te a greenish cast.

The bluish` tint usually found in the distillate is entirely absent from my product,

4and I attribute this to `the usefof caustic Within the crude during the period of distillation, experiments having shown Vthat Without the use of caustic, a very pronounced bluish fluorescence isv produced. AIt isfrfur-y ther desirable to employ a Weak acid treatment in accordance. With my process, since I have found that the distillate can be further refined by means lof clay Without first neutralizing With caustic soda or soda ash .tarry matter commonly called acid sludge.

This is due to the fact by my process the unsaturated hydrocarbons are removed Without interference With the cyclic or naphthene ring compounds.

The presence of the naphthene ring compounds is obviously a very desirable feature, and is primarily the result of'the relatively light acid treatment to which the oil is subjected.

By introducing a small amount of weak caustic into the crude and agitating the mass prior to Vsubjecting the oil to distillation, I find that various organic acids, resins, phenols, sulfo-acids are converted into stable alkaline products by distillation and remain behind as part ofthe bottoms.

In treating the crude With caustic and then heating and distilling to temperatures as high as 675 Fahrenheit and 700o Fahrenheit, the naphthenic acids and other organic acids are neutralized and as stated, stable alkaline products such as sodium salts are formed by reaction With the nitrogenuous and oxygenated bodies present.

I have tested the product produced in the above manner, and find that the oil is stable at high temperatures. For example, a qua-ntity of the finished oil has been subjected to a temperature of substantially 300 Fahrenheit more or less for a considerable length of time Without material cha-nge either in color or quality.

It Will be understood from my process that the percentage of bottoms Which is lost in the single distillation as Well as the percentage of` sludge Which is lost in the acid treatment is very low, and since it has been definitely established that the so-called bottoms obtained during the refining process of a lubricating oil contain the most valuable lubricant, the importance of my improvements can be readily seen.

Furthermore, by using a Weak sodium hydroxide solution, or other caustic solution,

there seems to be an increased tendency of vthe oil not to crack at the higher tempermoved by Washing.

My process is furtherr characterized by the fact that air-.is excluded so that no oxidized il? i 'there is no 'lossof'cri'ifde by reason "tionV of voil and f'saii'stic liquor.

' of the oil. With a strong solution, it'vvould vbe almost impossible to obtain 'a `clean cut Vsepai"ation of the oil andv alkaline solution. 'Moreover, by usine` a Weak :caustic solution, the percentage of objectionable products, such as soaps amount. f

If la' strong caustic 'solution Were used,

V'there is a possibility of the entire ``charge emul'sifying -Which is difficult to break, often requiring a separate distillation. With'my process 'employing a Weak caustic :solution during heating and distillation,

of separa- Moreover', no emulsification takes place and `there is lno'loss 'due togsuch reaction. I also find that when 'subjected' to further chemical treatrne'ii't, the possibilities vof emulsica'tion Vof the distillate is reduced to a minimum.

It will be observed that the use of complil cated apparatus is reduced since no double effect in 'the 'cost of 'production and my in-` distillation is necessary and 4the neutralizing step inthe chemical treatment may be eliminated. Moreover, the initial alkali treatment is carried on Without lany additional apparatus.

The time of operations for conducting my process is materially reduced, and this, of course, is a very important item.V

Both time 'and apparatus for y'have their vention very materiallyreduc'es the expense of refining "as will be quite clear.

Bythe fuse of the improved method of refining lubricating oil, a product having a green cast can be produced, and Aalso a Vred oill having ra green fluorescence can befohtained There is but a single'ldistill'ation 'and no necessity ofbl'ending when Voperating in 'accordanceWith my process. Also, it should be borne lin mind that Athe treatment herein described results in a very high Yield 'olfexeent qualify lancering 0a et 'a relatively vsmall cost and SWithiria time 'period vvhich has been much shortened over Athe present accepted methods.

necesi er @green 'Casi intra-atie@ en,

isreduced to an inappreciable A Y 'my hand. i It Will be understood that YWhere theusu'a'l processes l having for their; purpose thepr'otuate thellcast, my process-'gives a uniform product of green cast for both red and pale "oils Without further treatment. v

Blending of bottoms from `cracked fuel with a distillate is 'one artificial expedient, Whilethe 'use of bright vstock is another. Such additional-treatments are enormousily erpensive from the standpoint of operation, but have heretofore been necessary'to vgive the oil the desired color and render it marketable. Y

My process obviates this and not only shortens materially time of `operation and cost of blending material, but actually utilizes the majorpart of the bottoms Which Yare considered the valuable constitutent and Were hertofore generally unused in the direct vrefining treatment. By using "a caustic crude and following the steps heretofore outlined, my process gives'a clear product having a- 'percepticle and stable greenish cast.A i

I claim:` v

l. The process of refining oil vvhich coinprises introducing the oil into a still, adding a smallv quantity ofVv dilute, caustic, all- Akali solution thereto, distilling'off the lighter fractions, continuing distillation of the remaining charge of Vcaustic and oilY until substantially live percent of bottoms remain,

reducing said last mentioned distillate by heating to V remove lighter fractions only, subjecting the reduced distillate to a vchemical treatment vvith acid of less than ninetyveight percent concentration, removing the .f

sludge, treating With absorbent clay to decolorize the oil, ltering theV oil, and subjecting the oil Vto la brightening treatment.

2. The process of refining oil' which comprises introducing the oil into Ia still, adding .1 `a small quantiyfof dilute,-

caustic, alkali solution thereto, Vdistilling off the lighter Y fractions, continuing 'distillation of the remaining charge of caustic and oil until 'substantially Vfive percent of bottoms remain, reducing said last mentioned distillate by heating to remove lighterV fractions only,

subjecting Vthe reduced distillate to a chemical treatnient W'ith yacid of less than ninety- `eight percent concentration, vremoving the sludge, heating the distillate to reaction temperature-With a decolorizing agent, introducing a decolorizing agent into the distillate vv'hen 'the latter is at sucha temperature that the agent Will immediately react,

continuously filtering to separate the oil and "agent, and subjecting the filtered distillate,

While still-in heatedy condition', to a vacuum treatment.

' In testimony vvlier'eof I have hereunto set WILLIAM T.- 'BRYANT.

prey-'artificial mener acqui-'re and aeoen- Egli

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