US2781315A - Method of purifying, concentrating, and converting petroleum sulfonates with ketones - Google Patents

Method of purifying, concentrating, and converting petroleum sulfonates with ketones Download PDF

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US2781315A
US2781315A US442599A US44259954A US2781315A US 2781315 A US2781315 A US 2781315A US 442599 A US442599 A US 442599A US 44259954 A US44259954 A US 44259954A US 2781315 A US2781315 A US 2781315A
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oil
water
sulfonates
sulfonate
soap
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Ulric B Bray
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Bray Oil Co
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
    • C07C303/42—Separation; Purification; Stabilisation; Use of additives
    • C07C303/44—Separation; Purification

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  • BRAY NLM METHOD'OF PURIFYING CONCENTRATING AND CONVERTING PETROLEUM SULFONATES WITH KETONES 4 Sheets-Sheet 3 Filed July 12. 1954 Feb. 12, 1957 u.
  • This invention relates to the puriiication and concentration of hydrocarbon sulfonates of ⁇ the oil-soluble or mahogany acid type, and to the conversion of these sulfonates to polyvalent metal sulfonates.
  • This applica- 4tion is a continuation-in-part of my earlier application Serial No. 167,798, filed June 13, 1950, issued as Patent No. 2,689,221.
  • the sulfuric acid treatment lof petroleum lubricating oil results also in the production of other sulfonic acids, known as green acids, which are primarily water-soluble and are, therefore, found chieyin the acid sludge layer.
  • green acids sulfonic acids
  • some of these watersoluble green acids are found in the presence of the oilsoluble mahoganyv acids in the oil layer and are objectionable for certain purposes.- Possibly these vagrant watersoluble sulfonic acids pass into the oil layer because they are at the same time moderately oil-soluble, or because they are to that extent solubilized by the action ofthe mahogany acids, or because of the failure to remove the last traces of pepper sludge from the acidtreated oil.
  • these objectionable Water-soluble greenacids are carried over as sulfonate into the oilsoluble sulfonate which is commonlyplaced uponthe market as the sodium salts of the mahogany acids.
  • these sodium mahogany acid salts are commonly converted by metathesis ⁇ into alkaline earth metal sulfonates usually the calcium or barium salts.
  • the calcium salts of the true mahogany acids appear to bealmost entirely insoluble in water although oil-soluble. But the resultant calcium salts of the green acids, whichare readily water-soluble, are lapparently also-oil-solublcrin the presence of mahogany acid salt.
  • Another object is to separate the green acid sulfonates and inorganic sulfatos or other inorganic salts which would form insoluble salts with calcium or other polyvalent metal to be used, as water-soluble forms in a Water and emulsion-breaking liquid layer from whichthe oil and water-soluble, alkali-metal and ammonium mahogany sulfonates present are caused to separate.
  • a particular object is to-remove excess oil before conversion of the mahogany sulfonate to the water-insoluble, polyvalent-metal form.
  • lt is also an object to separate the objectionable inorganic salts mentioned in a Water-soluble form whereby to ⁇ avoid the necessityof subsequently iiltering their insoluble forms from the oil-sulfonate product, and whereby to reduce employment of lter aid and the like-and the incidental costs thereof.
  • individual objects are: to eliminate all green acid sulfonates; to eliminate all objectionable inorganic salts easily and without excessive employment of lter aid; to eliminate easily any proportion of excess oil from the sulfonates; and to provide such a process adaptable to the usual crude sodium sulfonates containing, for example, up to or 85% mineral oil of various lubricating viscosities and from perhaps 0% to 50% or 60% water based on the oil-sulfonate content along with V1% to 5% of inorganic salts, approximately, such as sodium sulfate and sulfi/te.
  • Fig. l is a flow diagram representing the major steps of the process when operated batchwise;
  • Fig. 2 presents curvesV showing Various relationships among various component materials present during the operation of the process
  • Fig. 3 is a ow diagram representing the principal steps of the process when operated continuously in single or multiple stages.
  • Fig. 4 is a ow diagram representing the principal steps of the process when operated countercurrently.
  • water-soluble and oil-soluble are used to signify either partial or cornplete miscibility or solubility in water and oil respectively.
  • soap will sometimes be used to signify the respective sulfonate.
  • concentration refers to the concentration of the sulfonates with respect to the oil present unless some other meaning is obvious.
  • crude petroleum sulfonates In treating crude petroleum sulfonates, various crude materials are encountered, some of which have been extracted from acid-treated oils as in the manufacture of white oils. These extracted crude sulfonates commonly contain between 25% and 60% (usually about 40% or 50%) petroleum oil of various lubricating viscosities, various sulfonate contents between about 30% and about 60% soap including between about one-half percent and 3% green acid soaps, and from 4% to 12% (for example, 8%) of sodium sulfate and sodium sulte of which the sulfate predominates. Where the crude sulfonate is a neutralized sulfonated oil, it will usually contain about 50% to 90% of oil neglecting water and salts present. The inorganic salts content of neutralized sulfonated oil will usually range from 0.75% to 4%.
  • the sulfonates are commonly salts of the alkali metal sodium and are water-soluble. They are to be purified to eliminate the green acid soaps, the sulfites and sulfates mentioned, the water, and any proportion of the oil which is not desired in the nal product and which will be ordinarily referred to herein as excess oil.
  • the green acid soaps are to be removed because of their deleterious effects in the end products, and the sulfates and sulfites are to be removed because they interfere with the emulsifying properties of the sodium sulfonate and constitute impurities therein if permitted to remain.
  • the present invention involves certain new discoveries that I have made. rlfhus, I have found that, at appropriate temperatures, I am able to purify crude, water-soluble, alkali-metal sulfonates before conversion tothe waterinsoluble, polyvalent-metal forms by commingling them with controlled proportions of water and of an emulsionbreaking, oil-soluble, at least partially water-soluble organic liquid, the objectionable inorganic salts and green acid sulfonates passing into a water layer which settles out as a brine upon standing. Such treatment may be effected with very large gallonage and is facilitated where the water is present as a weak sodium chloride solution, for example a solution.
  • excess oil may be separated from the water-soluble alkali-metal sulfonate by controlling the proportions of water and emulsion-breaking liquid respective to the soap-oil content of the crude sulfonate.
  • proportion of water and emulsion-breaking liquid respective to the soap-oil content of the crude sulfonate.
  • emulsion-breaking liquid Generally, by holding the proportion of emulsion-breaking liquid constant at a low level between 5 and volumes (or up to 40 to 50 volumes) per 100 volumes of soap-oil mixture (reckoned together) in the crude stock and adding water in increasing amounts, first a brine phase appears which settles to the bottom and may be drawn off as indicated above. Further additions of water cause an oil phase to appear which rises to the top and is readily separated from the then concentrated soap layer.
  • This rejected oil phase contains only a fraction of a percent of soap but does contain a few percent of the emulsion-breaking liquid and water.
  • the rejection of the excess oil is increased as the proportion of either the emulsion-breaking liquid or water, or both. is increased, and appears to be practically independent of whether or not the brine phase is removed as soon as it appears; but unless the brine phase is removed after appearing, it will go back into solution upon further addition of solvent and water.
  • the alkali-metal soap in the soap-oil concentrate layer which contains the water and the emulsion-breaking liquid, may be easily ⁇ converted to water-insoluble, oil-soluble', polyvalent-metal soap by mixing therewith a water solutionV of a salt of an appropriate polyvalent metal, the mixture being allowed to stand at appropriate ternperatures for a moderate time whereupon sharp separation results between the polyvalent-metal soap and oil layer and the aqueous layer.
  • the emulsion-breaking liquid (which is also often-herein designated as the solvent for convenience), this may be any oil-soluble, at least partially water-soluble organic liquid described below and consisting of carbon, hydrogen and oxygen, of suitably 10W boiling point toY facilitate its removal and recovery from the various phases and of sutiiciently low viscosity not to disturb seriously the various operations.
  • suitable boiling point it is intended to signify a boiling point below the decomposition point of the sulfonates so that the diluent liquid may be eliminated from the productby vaygioiiiia'- tion.
  • Thislclass of emulsion-breaking liquid solvents (which are often herein referred to merely as solvent for convenience) is at present best represented by any :of the liquid ketones having a carbon to oxygen ratio in the respective molecule not higherthanfour atoms of ⁇ carbon to one atom of oxygen, and ⁇ as indicatedin thefollowing list of examples. Morespecifcally, I have successfully used, -for example, the following: Y
  • a second oxygen may be present in a hydroxyl group as in the caseof diacetone alcohol and for the present purpose such a ketone alcohol is placed in the ketone classification and all the oxygens areV calculated as ketone oxygens.V
  • ketone which I have particularly preferred is methyl ethyl ketone (frequently'designated as MEK), partly because of its Vlow cost and easy volatility facilitating recovery by distillation.
  • MEK methyl ethyl ketone
  • the foregoing crude alkali-metal (sodium) sulfonate contains about 7.5% water, 16% total sulfonates, 74.5% oil, and 3% inorganic salts.
  • the inorganic salts are principally ⁇ sodium sulfate with a very minor portion of sodium sullite, both of which are to be removed by this method.V
  • the total sulfonate content consists of .14.5% mahogany acid soap and 1.5% green acid soap. It is desired to remove the green acid soap without loss of mahogany acid soap. It is desired also to remove excess oil and produce a concentrated calcium sulfonate containing 40% soap. It is further desired to convert any trace of sodium sulfonate appearing in the removed oil ⁇ to calcium sulfonate in order that the removed oil may be used in formulating engine oils, rust vpreventive oils, etc.
  • water is added in an amount equal to approximately 20% of the crude stock, corresponding to 21.5% based on the oil-soap content of the crude stock.
  • a 5% sodium chloride solution is employed because the' sodium chloride serves eliciently to displace .the sodium sulfate and the sodium sullite so that the latter salts will come out in a settled brine layer.
  • the ketone may be saturated with water and contain about 30% to 40% water. Appropriate allowance is made for such water content of the solvent in Vformulating the treatment of a batch of stock.
  • vthe lsodium chloride solution and the solvent are in- In using methyl ethyl ketone, or other over nght,forother appropriate period of timewhich may range from four or tive hours up to any other desired time.v During this Vinterval the temperature gradually drops with this volume of material to about F., the temperature, however, being at all times adequately high to assure good separation of a water (brine) phase which settles out in thcbottom of the tank, as indicated, and carries with it all objectionable proportions of green acid soaps, sodium sutlte and sodium sulfate, and similar objectionable inorganic salts.
  • the temperature range of 140 F. to 170 F., above indicated, hasthe further advantage that the separation of solvent vapors is small. In practice such vapors as do accumulate in the top of the tank are conducted to a solvent recovery system.
  • the separated brine layer is Withdrawn from the bottom of the tank.
  • the brine layer measured 12 gallons at about 140 F.
  • the soapsolvent layer measured 76 gallons, there being 52 gallons of oil which was rejected.
  • the withdrawn brine is passed to a still and the dissolved solvent driven ⁇ off and recovered.
  • the above described soap layer containing the oil, solvent, and mahogany soap is passed from the tank 12 through a heater 14 and upon its way to the heater is mixed with a quantity of tap water and/ or solvent sufticient to unbalance the previous solvent relationship between the oil, soap, and solvent so that upon further standing and settling any desired proportion of the excess oil in the soap-oil-solvent layer is rejected depending on the amount of water and/ or solvent added.
  • water equal to 20% of the original charge of crude stock was introduced.
  • the soap-oil solvent mixture with the added water is raised to a temperature of about F. to 170 F. as before, and this mixture is then either returned to the tank 12 or passed to another tank 15 as indicated in the ilow diagram, where it is agitated to insure equilibrium being established again.
  • the heated mixture is again allowed to stand and settle over night, or for several hours, so that the oil rejected by reason of the change in the solvent relationship separates as a supernatant layer above a soap-oil concentrate containing the solvent and the water.
  • the crude stock contained 74.5% oil
  • approximately 90% of the oil in the crude stock was rejected into the supernatant layer, while 10% of the oil in the charge remained in the underlying soap layer.
  • oil appears to be rejected under a given set of conditions until the ratio of soap to oil in the soap containing phase satisfies the equilibrium requirements for that set of conditions (appatently without regard to the quantity of oil in the original charge of stock).
  • the proportion of oil to soap is already below the equilibrium requirements, no oil will be rejected under that particular set of conditions.
  • aqueous soap concentrate (containing the solvent and some oil) which settles out in the tank 15 is next subjected to treatment to convert the alkali-metal, water-soluble, oil-soluble, mahogany sulfonate into a water-insoluble, oil-soluble, polyvalent-metal takY'ISt'oV a heater 16 forest-ore Vits"'temper”attir, and by comniiiigliiig thisconcentrate-with a water solutin'r'f an appropriate polyvalent-metalsalt.
  • the calciumsoap-oil-solvent layer ⁇ is then passed toa still 22 to distill ol the solvent, which is recovered and Sent to storage, and to'dehydrate the oil-soap concentrate to yield a finished productwhich may be placed in storage, as in a receptacle 24, either ⁇ with or without ilte'ring or other further treatment.
  • the heated mixture is allowed to s'tandinthe tanl; .'iuntil thelwater solution "separateswin'l thefbottorn and leaves V'ai supernatant oil layercontaining thesm'all amount of resultant calcium sulfonate.- Suchoil; whichds'commonly of lubricating viscosity, isuseful'in lubricating, rust ⁇ preventing,v and other petroleum compositions Iand is therefore dehydrated and recovered asV a valuable product.
  • calcium sulfonate concentratehaving a sulfated ash value of 7% to 8% may be obtained, and a yield of by-product (rejected) oil havingra sulfated ash value of about 0.02% to 0.10% maybe obtained.
  • the dosages of water (or NaCl solution) and emulsion-breakingliquid are Vbest selected* with respect to each other.
  • Fig.- 2 it is apparent from Fig.- 2 that, for eachy solvencdosagein thelrange of 5% to 15% basedV on theoil-soap'content of the stock, Vthere is :inappropriate range'of water content of the mix (the sumV ofbotlrthe water present inthe stock and the water added) for any given solvent content.
  • This appropriate water contentof the mix will usually be found in the range' of 10% to 60% Water based on ⁇ the oil-soap content of the stock.
  • the yieldv of brine layer was 12 parts as corn'- pared with 15 parts in 'the ⁇ second, but the vbrine in the first case was more concentrated. (Other crude sulfonates will have somewhat different optimum ranges'but the appropriate range will be found Within the'general order of magnitude indicated Ifor the stock shown above.) While the extraction ofY impurities was about the same in the two cases, it -willbe noted that in the rst case only a brine phase separated on settling,'leaving a soap-oil layer orf 118 parts, ⁇ whereas in the second case a rejected oil layer (61 parts) appeared on top of the concentrated and puried soap'layenthereby making three layers.
  • Vit'is preferable toL avoid simultaneous rejection of oil along with thebrine, as for example in one method of operating a continuous extraction column, but in the batch method, simultaneous separation of oil is of little consequence, and the dosages of solvent and water are chosen to give the optimum extraction of salts and other watersoluble impurities regardless of simultaneous rejection of oil from the soap phase.
  • sucient oil is rejected under conditions of optimum extraction of water-soluble impurities, then subsequent rejection of oil is obviously unnecessary and the concentration step istherefore completed along with the purification;
  • the purification conditions chosen do not reject the desired proportion of oil, then the brine phase is removed'and additional water is then added to bring up the vtotal water used (including water originally in the stock) to the place on the curve where the'desired amount of oil is rejected. Instead of adding water, morel solvent, or both solvent and water, may be added to cause additional rejection of oil.
  • the purificationand concentration are to be conducted sepal rately, thebrine'settled in the' purification step should be to 50% based on the oil-sulfonate content.
  • the excess water is removed by evaporation substantially in toto or, if desired, until the amount remaining corresponds to the working range for the usual solvent dosage of 10% to 35%.
  • the evaporation may be by ⁇ distillation or by heating and air blowing. In general the most satisfactory procedure is to remove most of the water and then add back the desired amount as the stock is processed in accordance with this invention.
  • the method of treatment is batchwise for each of the purification, concentration, and conversion steps. In many instances, however, particularly where the demand for the finished sulfonate is steady and of sufficient magnitude, it is desirable to operate the process in a continuous manner.
  • Figure 3 illustrates continuous operation of the process with single stage treatment by the reactants.
  • Pig. 4 illustrates continuous operation of the process with countercurrent iiow of reactants.
  • Many moditications and conrbinations of the steps will be readily apparent to those skilled in the art from the disclosures contained herein. For example, multiple treatments may be given at each step of the process of Fig. 3, when necessary to obtain complete results.
  • the crude sulfonate in a storage tank 31 is fed by a pump 32 at a controlled rate through a line 33 to the processing system.
  • the emulsion-breaking liquid solvent specified herein is charged at a controlled rate lthrough a pump 34 into the line 33 through which the crude sulfonate is owing.
  • Water or aqueous sodium chloride solution is charged through a pump 35 at a controlled rate also into line 33 through which the crude sulfonate and solvent are flowing.
  • the mixture of crude sulfonate, solvent and water flows into a mixer 36 which is equipped with suitable agitators and bafes to insure chemical equilibrium of the reactants and reaction products as they emerge from the top of the mixer 36 -through a line 37 and iiow into a settling vessel or purifier 3S.
  • a settling vessel or purifier 3S In this vessel, the soda brine phase containing sodium sulfite, sodium sulfate and other water-soluble impurities, such as green acid soap', settles to the bottom and the purified sulfonate rises to the top.
  • the settled soda brine is withdrawn through a valve 39 actuated as by a suitable liquid level control device (at Ithe interface) in vessel 38 and sent to a solvent recovery still where the solvent is recovered, and the brine is then discarded.
  • the purified sulfonate practically free of brine droplets overows from the tank 38 to a line 40 through which it is forced by a pump 41 into a mixer 42. Water is charged by Va pump 43 into the line 40 through which the purified sodium sulfonate is owing.
  • Mixer 42 is equipped with suitable agitators and bafes to insure equilibrium between the reactants and reaction products by the time they emerge through an upper line 44 and flow into a settling vessel or oil rejector 45.
  • the mixture entering the vessel 45 stratities into a concentrated soap and oil layer settling to the bottom and a rejected oil layer rising to the top and removed through an upper line 45a.
  • the concentrated soap layer is transferred from the bottom of the vessel 45 through a lower line 46 by a pump 47 and a valve 48 which are controlled by a suitable liquid level device 'in the settling vessel 45.
  • a relatively concentrated calcium chloride solution is charged by a pump 49 into the line 46 through which the concentrated sodium sulfonate is owing, this stream passing to a converter or mixer 50 equipped with suitable agitators and baflles to insure thorough equilibrium between the reactants and reaction products when the mixture emerges at the top through a line 51 by which it is carried into converted concentrate settling vessel SZ.
  • the mixture entering the settling vessel 52 straties into two layers; namely, (1) an aqueous phase containing sodium chloride formed by metathesis from the calcium chloride, excess calcium chloride, and other water-soluble impurities such as the last portions of green acid soaps, and (2) an oily phase consisting of oil, converted sulfonate, and the major portion of the solvent carried through the process to this point.
  • the oily phase rises to the top of the settling vessel 52 and overilows through a line 53 from which it is charged by pump 53a to a solvent recovery still 54.
  • a slurry of calcium hydroxide in either oil, Water, or calcium chloride solution is prepared in an agitator 55 and pumped via a line 55a and a pump 56 into the line 53 carrying the converted soap layer to the solvent recovery still 54.
  • the still 54 is duplicated, one still being used for distillation while the other is being charged, or the converted soap layer supplied by the line 53 is accumulated -in an intermediate storage tank (not shown) while a batch is being run down in the still 54, or the still 54 may be of the continuous type consisting of a tubular heater and fractionating tower.
  • Either steam or vacuum or both may be used in the still to aid removal of the last traces of solvent 'and water from the converted soap layer.
  • the converted soap layer is nally heated to a temperature in the neighborhood of 300 F. and then filtered in a filter press 57 and sent to storage 58.
  • a small amount of diatomaceous earth e. g. Supercel, Hyo
  • the solvent from the converted soap layer is recovered in apparatus 59 for reuse in the process.
  • the calcium brine layer is withdrawn from 'the Abottom of the vessel 63- throughtvsuitableglevel-,controllvalvesf-and pumps (not shown) and is processed'for recovery-of4 dissolvedsolvent and-then discarded.- A- small portion of this brine can be used infftheE agitatorSS, if desired; in making ⁇ a calcium hydroxidel slurry-to-be added Yeither to the concentrated soapalayenbeing ,chargedto the still 54 or to theconverted, rejectedV oilflayer' charged 'tothe still 65.
  • the still 65 when being processed in the still 65 may contain a slurry of calcium hydroxide suspended inl oil or water or brine containing calcium chloridel added from theagitator 55,V as ab'ove indicated, or from an agitator 66 by a pumpt67 via aline 68, to the charge goingtinto the still 65; Irv-this still, both dissolved solvent'A and -water areV removed 'by heating to atemperature in' the neighborhood of SOO'VF. with the useof vacuum ⁇ or steam. The liberated ⁇ solvent is recovered in appropriate apparatus A69- ⁇ for reuse -in the process.
  • the dehydrated solvent-'free oil ⁇ isfiil'teredl-and sent to storage'70 Vfor usen blending lubricatingoils-rust preventives, and the like,orit may be ⁇ fur'ther'relniedto produce white oils.
  • the temperature is'preferably higherthan in the'batch method illustrated in Fig. 1, to insure ecient operation of thecontinuous settling vessels; namely, in the neighborhood of ⁇ l60 F. to 200 F. aspreviously indicated.
  • Appropriate heaters (not shown) are ⁇ employed in much the' same way as shown in Fig. 1. Care is taken to avoid loss of solvent by vaporization, even to the point of operating all mixers and settlers under pressure.
  • the higher boiling solvents of the disclosed class are often preferred'in the continuousfme'thodof operating the process at the 'higherA temperature, because they are more readily'recovered from the various brines and products with less vapor loss.
  • Higher temperatures e. g. 160 F. to 200 F., withL operation under pressure are employed in such countercurrentV operationslin much the sameV manner as for the process of Fig. 3.
  • Figure 4 illustrates a countercurrent, continuous operation of1 the process, the crude sulfonate in storage tank Y 71 being fed by Ia pump 72'at a controlledrate through a line 73 to the processingsystem.
  • TheV emulsion-breaking liquid solvent specified herein is charged'ata controlled rate by1a pump 74 into the line 73 through whichv the crude sulfonate is flowing.
  • the mixture of stock and solventi enterstthe lower portion of acountercurrent extraction column 75 whilewater or aqueous sodiumchlo-V ride is charged at a controlled rate by a pump 76 and a line 77 into the upper portion of the extraction column 75.
  • the water or ⁇ sodium chloride solution works its way downward and extracts from the stock the water-soluble impurities such as sodium sulfate, sodium sulte and the green acid soaps.
  • the brine thus formed settles in the bottom of the column 75 and is withdrawn .through a valve 78 which is actuated by a suitable level control in the column 75 and is sent to a still for recovery ofthe ⁇ solvent dissolved therein..
  • any additional calcium chloride solution introduced bythe pump 102 moves countercurrentto the reacted -oilyy soapy phase risingv in the column 97 and serves to complete the conversion of'sodium'soapto calcium soap.V
  • the converted soap" phase flows out the ltop of'column 97l via'a line 1051 and a pump 106 and is sent tointermediate storage tank 107 whence it is sent to a still-108, for recovery of ⁇ solvent-in apparatusx109, and dehydration before filtering.
  • - Lime-or other reagents' may be 'added to the stock in vthe tank 1ll7 before it is charged to the still 108 by a pump 110.
  • Diatomaceous earth which serves asia iilter aid is added before, during, or after'the :distillation and dehydration.
  • the dehydrated concentrate is passed through a lilter 111 and thefinished calcium sulfonate concentrate is sent to storage 1712.
  • the oil rejected in the rejection column 82 rises upward and settles practically free of entrained water and 'f soap in the top of the column. However it contains a very small proportion of dissolved mahogany soap which should be converted. Therefore, the rejected oilY is passed from the top of the column 82 via a line 115 and a pump 116 into a treating column 118, Aand calcium chloride solution, which may conveniently be the partially spent brine layer settling to the bottom of extraction columnv 97, also is introduced into the top of column 118 via a pump 119 and a line 120, or into the bottom of the column 118 via a pump 121 and a line 122.
  • Any calcium chloride solution introduced via pump 119 is best mixed with the rejected oil phase flowing in the line 115 by passing the mixture through an agitator 123 before it goes into the treating column 118.
  • the operation of the conversion of the small amount of soda soap carried over in the by-product oil owing from the top of the rejection column 82 is similar to the conversion of the concentrated soda soap phase settling to the bottom of the column 82 and converted and separated in the column 97.
  • the converted, rejected oil in the column 118 'rises to the top and is sent via a pump 124 and a line 124a to intermediate storage 125, whence it is charged by a pump 126 to a still 128 for solvent recovery in apparatus 129 and for 'dehydration before filtering. VAfter passing through a filter, this converted, rejected oil is sent to storage for use as a lubricant, or in compounding rust preventivas or lubricants, or the like.
  • the brine phase in the column 118 settles to the bottom and is withdrawn via a valve 131 and a pump 132 which are controlled by Ia suitable liquid level device (not shown) in the lowest portion of the column 118. This brine is distilled for solvent recovery and is nally discarded.
  • this process is also applicable to the treatment of alkali-metal or ammonium sulfonate-ol concentrates of commerce whichr contain around 30% to 60% sulfonates and to 70% oil with impurities in the form of green acid soaps, sulfates, sultes, and the like, although this process is particularly adapted to the treatment of sulfonated oils containing the indicated lower soap contents.
  • the purified polyvalent metal petroleum sulfonates or mahogany soaps obtained in accordance with this invention are usually calcium products
  • the invention nevertheless extends to the preparation of other alkaline earth metal sulfonates, especially barium and strontium salts. These may be prepared with Watersoluble salts of barium and strontium as readily as the calcium product is produced.
  • the process is also applicable to the production of other water-insoluble, oilsoluble sulfonates, and these may include the mahogany acid salts of aluminum, zinc, magnesium, lead, cobalt, nickel, and the like.
  • Concentrates of the above nature may be put to various uses.
  • the above concentrate to calcium, aluminum, barium, magnesium, zinc, and lithium base greases, respectively, has both imparted markedly improved anti-rusting properties and reduced tendencies to bleeding or separation of the oil content of the greases on standing.
  • Rust preventives-constitute another important phase of use of the present product are obtained by diluting the appropriate polyvalent-metal sulfonate con- For example, the 4addition of 5% to 20% of centrate with appropriate carriers, such as anyl mineral oil lubricating fraction suitable for the ultimate use of T16 the product; Commonly, such dilution will yield Va sulfonate content between about .05% and about 6% in the blended product. Ordinarily a satisfactory working proportion is abouty 3% of sulfonate, or within a range of'about 2% to about 4%.
  • lubricating oils for severe service, internal combustion engines, such as aircraft and other heavyduty engines, including diesel engines.
  • sulfonate may be present in proportion to impart rustpreventive characteristics or for other purposes, including promotion of detergent and Wear-reducing characteristics.
  • typical lubricating oils may contain from about 0.5% to as much as 10%, for example 3%, of the purified alkaline earth metal sulfonates of this invention, together with suchother Yadditive constituents as may be deemed desirable.
  • such other materials may include sulfurized alcohols, sulfurized hydrocarbons, thiophosphates, Zinc dithiophosphates, phenolic thioethers, phosphites, metal derivatives of these materials, various oil-soluble detergent soaps, such as the calcium soaps, and similar metal soaps of synthetic' carboxylic acids obtained from the oxidation of paraiimic hydrocarbons, alkyl phenols, pour point depressors, anti-oxidants, viscosity index improvers, and kindred materials known in the lubricating industry.
  • wreka-liquid-15 which comprises: forminga .mixture consisting essen- Vtially or" saidhydrocarb'on oil, said alkali metal mahogany sullionates, said alkali smeftalgreeniacifd sulfonates, 4said water-soluble'inorganic sulfate and sulte, at least l0 parts by volume ot waiter per 100 'parts Vby Yvolume of said hydrocarbon oil and sulfcnates ⁇ and at least 5 Vparts by-volume .per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon voil-soluble emulsion breaking liquid which is a ketone selected from the class consisting of acetone, methyl ethyl ketone, diacetone alcohol, acetyl acetone andacetonyl acetone, the Vamounts of said water and said emulsion breaking liquid 4being suic-ient to produce three separ
  • hydrocarbon oil-soluble emulsion-breaking liquid which is a ketone selected from the class consisting of acetone, methyl ethyl ketone,
  • said Water, said sodium chloride and ⁇ said emulsion-breaking liquid beingsuicient to 'produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon oil, water and-emul-V sion-breaking liquid, a hydrocarbon oil phaserejected from said concentrated mahogany sulfona'te phase and an aqueous phase containingalkali metal green acid sulfon'- ates, water-solubleinorganic sulfate and sulte and a,

Description

Filed July l2, 1954 u. B. BRAY 2 METHOD 0F' PURIFYING, CONCENTRATING AND CONVERTING PETROLEUM SULFONATES WITH KETONES SL31 Si? 4 Sheets-Sheet l U. B. BRAY a METHOD OF PURIFYING, CONCENTRATING AND CONVERTING PETRQLEUM SULFONATES WITH KETONES Filed July l2, 1954 4 Sheets-Shet 2 .UAR/ws, 1050/, Fosrm c ZIA/Qms 12, 1957 u. B. BRAY NLM METHOD'OF PURIFYING, CONCENTRATING AND CONVERTING PETROLEUM SULFONATES WITH KETONES 4 Sheets-Sheet 3 Filed July 12. 1954 Feb. 12, 1957 u. B. BRAY 2,7@9315 METHOD 0F PURIFYING. CONCENTRATING AND CONVERTING PETROLEUM SULFONATES WITH KEITONES Filed July 1:2, 1954 4 Sheets-Sheet 4 om awww United States METHOD F PURIFYING, CQNCENTRATIVNG, `AND CONVERTING PETROLEUM SULFU- NA'IES WITH KETONES i Ulric B; Bray, Pasadena, Calif., assigner to Bray Company, Los Angeles, Calif., a limited partnership Application July 12,1954, Serial No, 442,595* 17 Claims. (Cl. 252-33) This invention relates to the puriiication and concentration of hydrocarbon sulfonates of` the oil-soluble or mahogany acid type, and to the conversion of these sulfonates to polyvalent metal sulfonates. This applica- 4tion is a continuation-in-part of my earlier application Serial No. 167,798, filed June 13, 1950, issued as Patent No. 2,689,221.
In the preparation of some rust preventing compounds and lubricants, and in the preparation of some lubricants for severe service uses and for similar lubricating uses, it has been a practice for many years to employ various metal salts of sulfonic acids derived from the reaction of sulfuric acid and petroleum fractions in the lubricating oil range. These sulfonic acids, and their salts are well known in the petroleum industry. Those most commonlyused forthe present purpose are the oil-soluble acids known as mahogany acids which are found in solution ina supernatant oil layer which accumulates above an acid sludge layer upon settling of `a batch of petroleum lubricating oil following strong sulfuric acid treatment. The sulfuric acid treatment lof petroleum lubricating oil results also in the production of other sulfonic acids, known as green acids, which are primarily water-soluble and are, therefore, found chieyin the acid sludge layer. However, some of these watersoluble green acids are found in the presence of the oilsoluble mahoganyv acids in the oil layer and are objectionable for certain purposes.- Possibly these vagrant watersoluble sulfonic acids pass into the oil layer because they are at the same time moderately oil-soluble, or because they are to that extent solubilized by the action ofthe mahogany acids, or because of the failure to remove the last traces of pepper sludge from the acidtreated oil. As aresult, these objectionable Water-soluble greenacids are carried over as sulfonate into the oilsoluble sulfonate which is commonlyplaced uponthe market as the sodium salts of the mahogany acids. For the purpose of. preparing rust preventing compounds and severe `servicelubricants, these sodium mahogany acid salts are commonly converted by metathesis `into alkaline earth metal sulfonates usually the calcium or barium salts. The calcium salts of the true mahogany acids appear to bealmost entirely insoluble in water although oil-soluble. But the resultant calcium salts of the green acids, whichare readily water-soluble, are lapparently also-oil-solublcrin the presence of mahogany acid salt. Because of theirwater-solubility, they are objectionable in'rust preventives and in lubricating oils where ymoisture maybe encountered, because they appear to weaken the resistance to water of an oil filmV on metal, possibly through favoring the formation of a water-continuous emulsion; whereas the water-insoluble, oil-soluble calcium salts of the true mahoganyacids, when operating in-the presence of water to form emulsions, result in emulsions where vfoil, isrthge continuous phase. inthe case of oilcontinuous emulsions, the oil preferentially wets iron or steel surfaces with the result that the water present in the"emulsion does'not wet the metal and rusting is fic 2. avoided. On the other hand, Where the chemical environment produces water-continuous emulsions, the water phase displaces the oil from the metal surface, thereby reducing or destroying the rust inhibiting effect of the oil. Even though the oil-soluble, water-insoluble sulfonates greatly predominate, nevertheless, appreciable proportions of water-soluble sulfonates result in undesirable stances, to concentrate such mahogany sulfonates with respectV to oil by eliminating excess oil therefrom, and then to convert to polyvalent-metal forms the mahogany sulfonates so puried and concentrated in order that they may be useful in corresponding rust preventive and detergent lubricating oil.
Another object is to separate the green acid sulfonates and inorganic sulfatos or other inorganic salts which would form insoluble salts with calcium or other polyvalent metal to be used, as water-soluble forms in a Water and emulsion-breaking liquid layer from whichthe oil and water-soluble, alkali-metal and ammonium mahogany sulfonates present are caused to separate.
It is also an object to provide a process for Vrecovering oil-soluble, Water-insoluble, polyvalent-metal sulfonates, such as calcium mahogany sulfonates, in oil, whereby excess oil beyond that desired in a given product is easily rejected in the presence of water and certain oil-soluble, emulsion-breaking, organic liquids, such as certain ketones, ethers and glycols. A particular object is to-remove excess oil before conversion of the mahogany sulfonate to the water-insoluble, polyvalent-metal form.
lt is also an object to separate the objectionable inorganic salts mentioned in a Water-soluble form whereby to `avoid the necessityof subsequently iiltering their insoluble forms from the oil-sulfonate product, and whereby to reduce employment of lter aid and the like-and the incidental costs thereof.
It is a stili further object of the invention to provide a process for the recovery of petroleum sulfonates whereby formation of difficulty breaking emulsions, such as theV fable materials and excess petroleum oil areV easily eliminated.
Thus, individual objects are: to eliminate all green acid sulfonates; to eliminate all objectionable inorganic salts easily and without excessive employment of lter aid; to eliminate easily any proportion of excess oil from the sulfonates; and to provide such a process adaptable to the usual crude sodium sulfonates containing, for example, up to or 85% mineral oil of various lubricating viscosities and from perhaps 0% to 50% or 60% water based on the oil-sulfonate content along with V1% to 5% of inorganic salts, approximately, such as sodium sulfate and sulfi/te. Y v
It is also an object to purify and/or concentrate crude `alkali-mahogany sulfonate for use as emulsifying and wetting agents or for other desired uses to which sodium, potassium and/ or ammonium hydrocarbon sulfonates and sulfates may be put.
It is also an object to provide a purification, concentration, and conversion process for crude sulfonates of the indicated character whereby very large batches of crude material of high oil content and relatively low sulfonate content may be so treated with relative ease, as against treatment of only relatively small batches as heretofore.
Other objects of the invention will become apparent from the following description, as will the various features of the invention. In connection with the following speciiication reference is made to the accompanying drawings wherein:
Fig. l is a flow diagram representing the major steps of the process when operated batchwise;
Fig. 2'presents curvesV showing Various relationships among various component materials present during the operation of the process;
Fig. 3 is a ow diagram representing the principal steps of the process when operated continuously in single or multiple stages; and
Fig. 4 is a ow diagram representing the principal steps of the process when operated countercurrently.
Throughout this specification, the terms water-soluble and oil-soluble are used to signify either partial or cornplete miscibility or solubility in water and oil respectively. The term soap will sometimes be used to signify the respective sulfonate. Where reference is made to removal or elimination of green acid soaps or inorganic salts, such terminology is intended to include either complete elimination or reduction of the respective materials to such insignificant proportions that the presence of the remainder does not interfere seriously with subsequent processing or itis not detrimental for uses to which the sulfonate product is eventually to be put. Where the term concentration is used, it refers to the concentration of the sulfonates with respect to the oil present unless some other meaning is obvious.
In treating crude petroleum sulfonates, various crude materials are encountered, some of which have been extracted from acid-treated oils as in the manufacture of white oils. These extracted crude sulfonates commonly contain between 25% and 60% (usually about 40% or 50%) petroleum oil of various lubricating viscosities, various sulfonate contents between about 30% and about 60% soap including between about one-half percent and 3% green acid soaps, and from 4% to 12% (for example, 8%) of sodium sulfate and sodium sulte of which the sulfate predominates. Where the crude sulfonate is a neutralized sulfonated oil, it will usually contain about 50% to 90% of oil neglecting water and salts present. The inorganic salts content of neutralized sulfonated oil will usually range from 0.75% to 4%.
The sulfonates are commonly salts of the alkali metal sodium and are water-soluble. They are to be purified to eliminate the green acid soaps, the sulfites and sulfates mentioned, the water, and any proportion of the oil which is not desired in the nal product and which will be ordinarily referred to herein as excess oil. The green acid soaps are to be removed because of their deleterious effects in the end products, and the sulfates and sulfites are to be removed because they interfere with the emulsifying properties of the sodium sulfonate and constitute impurities therein if permitted to remain. In addition, if these inorganic sulfates and sultes are retained, they are converted into insoluble polyvalent-metal compounds in the conversion stage and in the case of alkali earth metal and lead settle to the bottom of the treating tank as a mud which, in the presence of the sulfonates, is coated with considerable quantities of oil because of the wetting properties of the sulfonates and presentsl here'the problem of dicult separation or the element of unnecessary loss of a substantial proportion of oil and sulfonate.
The present invention involves certain new discoveries that I have made. rlfhus, I have found that, at appropriate temperatures, I am able to purify crude, water-soluble, alkali-metal sulfonates before conversion tothe waterinsoluble, polyvalent-metal forms by commingling them with controlled proportions of water and of an emulsionbreaking, oil-soluble, at least partially water-soluble organic liquid, the objectionable inorganic salts and green acid sulfonates passing into a water layer which settles out as a brine upon standing. Such treatment may be effected with very large gallonage and is facilitated where the water is present as a weak sodium chloride solution, for example a solution.
I have also discovered that excess oil may be separated from the water-soluble alkali-metal sulfonate by controlling the proportions of water and emulsion-breaking liquid respective to the soap-oil content of the crude sulfonate. Generally, by holding the proportion of emulsion-breaking liquid constant at a low level between 5 and volumes (or up to 40 to 50 volumes) per 100 volumes of soap-oil mixture (reckoned together) in the crude stock and adding water in increasing amounts, first a brine phase appears which settles to the bottom and may be drawn off as indicated above. Further additions of water cause an oil phase to appear which rises to the top and is readily separated from the then concentrated soap layer. This rejected oil phase contains only a fraction of a percent of soap but does contain a few percent of the emulsion-breaking liquid and water. The rejection of the excess oil is increased as the proportion of either the emulsion-breaking liquid or water, or both. is increased, and appears to be practically independent of whether or not the brine phase is removed as soon as it appears; but unless the brine phase is removed after appearing, it will go back into solution upon further addition of solvent and water.
The production of both a brine layer containing un'v desirable inorganic salts together with green acid soaps and a rejected oil layer containing excess oil can often be accomplished in one step by careful selection of the treating doses of water and emulsion-breaking liquid, re-
spectively. However, for greatest flexibility and ease of operation by less skilled personnel, it is usually preferred to conduct the purification and oil separation as separate steps, differing from each other mainly in the` amount of water present. Reference to Fig. 2 will show for example that, with a given amount of the particular emulsion-breaking liquid within a suitable range with respect to the oil-soap content of the stock, a brine layerwill appear upon increasing the water present (curves B) before a rejected oil layer will appear (curves A). However, continued increase of the water beyond a certain point causes the brine layer to decrease and eventually disappear; whereas when the critical amount of water has been reached to cause appearance of a rejected oil phase, further additions of Water cause increasing amounts of oil to be rejected and the total amount of oil rejected tends ultimately to approach asymptotically the total amount of oil present in the stock. Likewise, at a given water content up to a certain point, vthe yield of brine phase increases slightly with solvent dosage, but beyond this point increasing dosages of solvent result in decreasing yields of brine, whereas after the rejected oil layer appears, the yield of rejected oil continues to increase with increasing dosages of solvent at a constant water dosage, at least within the range of solvent preferred in this invention.
I have also discovered that after the removal of any brine layer settling to the bottom and the separation ot' `the rejected oil which rises as a supernatant layer, the alkali-metal soap in the soap-oil concentrate layer which contains the water and the emulsion-breaking liquid, may be easily` converted to water-insoluble, oil-soluble', polyvalent-metal soap by mixing therewith a water solutionV of a salt of an appropriate polyvalent metal, the mixture being allowed to stand at appropriate ternperatures for a moderate time whereupon sharp separation results between the polyvalent-metal soap and oil layer and the aqueous layer.
acetates, etc.
efinvw" Plfr t. h foa'tes arej(1) puriiiedby renfoviiginorg'anlc salt :and green acidmsoaps'intii'form Otan-aqueous -brine (2) coni;entrate'd`v by rejecting and removing :excess oil, and (3) `converted tc.: polyvalent-metalsulfontsl These three "steps arel etiiciently controlled I byi'the properfad'-l justinentof three variables;namelyfvariation oflthe proportion'ofwater, as above indicated, employmentfof an' appropriate proportion of emulsion-breaking liquid, and operation at aV suitable temperature.'V
Generally temperature is'not `a critical variable; how# ever,v temperatures mayran`ge in 'the neighbi'lodof 140 F, to 170 Fun/hen thevariousoperation's are con'- ductedfbatchwise, and 160 Fpto 200 F., when conduct'dina continuous manner,` for each of the'puritication, concentration, and conversion steps, are conveniently eno-layed. v
Et'rcien't' proportions of emulsioitt-breitking'liquid ordinarilyrangefrom aboutS lparts 'tolabout30l`pai't'sfr eaoh 100 parts of soap-foil (reckoned together)` in the crude sulfonate to be treated. I
As 'to water contents, while different stockshavets'oi'newhat diterentirequire'ments, as isalw'aysltiue inanytype of treatment of petroleum fractionsv oriderivtives, nevertheless, in general, approximately ,20'parts`f1to 160 parts of Vwater V(preferably largely sodium chloride Vsolution, are etectiv'e in the' purification stagefforeach "100 pa'rts of soap-oil (reckoned together) Vin'th'e"'crt1de""stock to remove objectionable inorganic salts, sodium sulfate and 'sodium sultite,- and the'undesire'd green acid` s`ul fonates- In the conoentratio stagejadditional water and/or emulsion-breaking liquid issupplied iff' 'f excess oil has beenrejctedduri'ri'g the purineH nstp. Ordinarily, 30 to SOVparts'of water totalper 100 parts of soap-oil (reckoned'together) in thev crude 'stock to be treated will givefsuitable rejection of excess oil.`
Additions of either water or the emulsion-breaking organic liquid or'both to a mixture Vwhose'composition is in the range for oil 'rejection will disturb'the solvency equilibrium and cause additional rejectionof oil into the supernatant layer. The resultant underlying "con' centi-ated soap layer'tslp concentrated'with respect to oil) may thus be made to contain oil in that proportion desired in the iinal product.l p
l have discovered that instead of using practically pure water (city drinking water), along with `the'einulsion-breaking liquid, `to wash out weitet-soluble impurities from a crude sodium sultonate-oilV mixture, loanedvan'tageously use an aqueous salty solution in' many instances. Where it is expected that purified sodirn`sulfonate will subsequently be convertedtocalciuin,-bariurn, or strontium suIfOnate, itV is very desirable' to'remove sulfates and sultit'es as far as practical toavoidforination ofthe water-insoluble sulfatesand suliitesA of theseipoly- 'valent metals during'the lconversiony ofthesoap.l The presence of anions which do not givefwater-insoluble salts with the polyvalent metals is not objectionable'from this standpoint, such anions being chlorides, nitrates,
in thewash water effects greater removal of the sodium sulfate and sulte in the brine layer during Vthe purification step, their use is often justied. In general, chlorides of the monovalent metals are preferred, especially sodium chloride because ot both its emciency and relatively low cost. When using sodium chloride solution in place of Water during'puriiicatotn4 the same behavior is obtained as is illustrated by the curves in Fig. 2, except that the amount of brine phase settling out for a given dosage'of solvent and Water, respectively, is both larger in volume 'and more concentrated `in V sulfates and sulites.
ingforganic liquidi and r-tli'e" resulting residue'isrecovered,
Therefore, if the presence of these anions 6 thot nal fprication-'f byfltering-or Scenf nis Whil. l If "al piid coneentratem polyvalent-'metal rsulfonate is'desired-as the end produchthe" concentratedzsoapflayer is reacted with an appropriate?watersolublepolyvalent; metal'salt-suchfascalcium chloride. l Usually'thel polyvalent-mtal-salt-is 'added in the form lof a concentrated aqueous? solution, but Withiproper agitation? the` solid `salt in the form of flakes, powder, orcrystals;mayibeA added directly VVto the' co'nc'entratedsoaplayer.l On vaccount/.of thel presence of :theY emulsion-breaking organic liq'uidgthe reactedlmixture*strtitiesireadily into a converted soap layer; contaningi'also thefre'naining oilland nost offthe emulsion-breakingorganicliquid, and anfaqueousphase containing-by-prduet isalts, excess reagentJ salt, and lla very small proportion of emulsion-breaking organic liquid-L The convertdj soap layer v'is separatedf'and distilledL or otherwise suitably treated` to recover" the ern'ulsionlbreak in'gorga'nic liquid'and finally Y dehydratdl and recovered asltheendproduetefterliltering or centrifuging' While heated".
While'ltempratures are not particularly critical, as mentioned before, nevertheless, at temperatures materially below F., viscosity/conditions become acon? sideiationl because they delay phase separatiom and @at lovv' rnperature's suchas around 100 F., the'separati'on of 5th va'riusphases may befinconveniently slow; Howeverfifsthe'tinie elementlis of little consequence, tempera tur's may be'usd down to 100 F., for example, without ditl'icul'ty.l 5 While"terriperaturesv as highy as 185 F. and up to about 200 F. produce rapid settling, they, neveri thelessf'niay complica-te' fthe matter' of maintaining adequatA conoentiiation of the emulsion-breaking-'-liquidin batchvvifseoperations. Therefore, a l temperatu'reof about S*F., or fromabout- 140 F.' to'l70 F., hasT-been found-'to beI a desirable optimum `and representative of `a goodv compromise betweenA speed 'of separation and settling of the-layers and retention of emulsion-breaking liquidin theV batches during such separation and settling. Discussion of preferred temperatures in continuous operationsris given below.
With -re'spect --to the emulsion-breaking liquid (which is also often-herein designated as the solvent for convenience), this may be any oil-soluble, at least partially water-soluble organic liquid described below and consisting of carbon, hydrogen and oxygen, of suitably 10W boiling point toY facilitate its removal and recovery from the various phases and of sutiiciently low viscosity not to disturb seriously the various operations. At least partially Water-solublesig'nies at least about 0.1% Vto '10% solubility or miscibility in water. By suitable boiling point, it is intended to signify a boiling point below the decomposition point of the sulfonates so that the diluent liquid may be eliminated from the productby vaygioiiiia'- tion. In general, this signifies a boiling point not materially in excess of 400 F., inasmuch as the initial decomposition temperature of a sulfonate, such as calcium sulfonate, may be in the neighborhood of 450 F. to 500 F. However, higher boiling solventscan be recovered by distillation under vacuum.
Thislclass of emulsion-breaking liquid solvents (which are often herein referred to merely as solvent for convenience) is at present best represented by any :of the liquid ketones having a carbon to oxygen ratio in the respective molecule not higherthanfour atoms of `carbon to one atom of oxygen, and` as indicatedin thefollowing list of examples. Morespecifcally, I have successfully used, -for example, the following: Y
, Y C10l ratio Acetone, CHsCOCHs 3:1 Methyl ethyl ketone, CHsCOCzHs 4:1 Diacetone alcohol, CH3COCH2C(OH) (CH3)2` 3:'1 Acetyl acetone, CHsCOCHsCOCI-Isy 2.5.: 1 v'Acetonyhacetone,` CHzCOCzHiCOCHa 3:'1
' As appears from the above list `a second oxygen may be present in a hydroxyl group as in the caseof diacetone alcohol and for the present purpose such a ketone alcohol is placed in the ketone classification and all the oxygens areV calculated as ketone oxygens.V
' The ketone which I have particularly preferred is methyl ethyl ketone (frequently'designated as MEK), partly because of its Vlow cost and easy volatility facilitating recovery by distillation. Y f
1 Having reference to the accompanying batch ilow diagram of Fig; l and also to a particular crude alkali-metal sulfonate which is a neutralized sulfonated oil as an example of various crude sulfonates which have been successfully treated, a preferred method of procedure, which embodies the various laspects of this invention is set out below. Y' Y The foregoing crude alkali-metal (sodium) sulfonate contains about 7.5% water, 16% total sulfonates, 74.5% oil, and 3% inorganic salts.- The inorganic salts are principally` sodium sulfate with a very minor portion of sodium sullite, both of which are to be removed by this method.V The total sulfonate content consists of .14.5% mahogany acid soap and 1.5% green acid soap. It is desired to remove the green acid soap without loss of mahogany acid soap. It is desired also to remove excess oil and produce a concentrated calcium sulfonate containing 40% soap. It is further desired to convert any trace of sodium sulfonate appearing in the removed oil `to calcium sulfonate in order that the removed oil may be used in formulating engine oils, rust vpreventive oils, etc.
Purification stage-To the particular starting material above described, water is added in an amount equal to approximately 20% of the crude stock, corresponding to 21.5% based on the oil-soap content of the crude stock. Preferably a 5% sodium chloride solution is employed because the' sodium chloride serves eliciently to displace .the sodium sulfate and the sodium sullite so that the latter salts will come out in a settled brine layer. The less ,sodium chloride used, the less efficiently are the sulfites and sulfates eliminated. While stronger concentrations of sodium chloride may be employed, or`15% for example, to obtain greater removal of sulfates and sulfites, the additional cost is usually not considered justied. This is particularly because the amounts of sulfates and sultes which are not removed by employment of a 5% sodium chloride solution in the proper dosage are insufficient to detract seriously from the usefulness of the purilied sodium sulfonate as such or as a raw material for making polyvalent-metal sulfonate.
To the crude sulfonate stock there is also added, between about and about 30 parts per 100 parts of stock of the selected emulsion-breaking organic liquid or solvent described, such as methyl ethyl ketone, based on the crude stock. indicated ketone, the ketone may be saturated with water and contain about 30% to 40% water. Appropriate allowance is made for such water content of the solvent in Vformulating the treatment of a batch of stock.
In a particular instance 100 gallons of the described crude sodium sulfonate stock containing about 16% total soap and about 7.5% water were pumped into a treating tank in admixture with 20 gallons of water and 20 gallons of the methyl ethyl ketone as the emulsionbreaking liquid and solvent.
As is represented in the batch ow diagram of Fig. 1,
vthe lsodium chloride solution and the solvent are in- In using methyl ethyl ketone, or other over nght,forother appropriate period of timewhich may range from four or tive hours up to any other desired time.v During this Vinterval the temperature gradually drops with this volume of material to about F., the temperature, however, being at all times adequately high to assure good separation of a water (brine) phase which settles out in thcbottom of the tank, as indicated, and carries with it all objectionable proportions of green acid soaps, sodium sutlte and sodium sulfate, and similar objectionable inorganic salts. Not only do the sultes and sulfates separate in the lower brine layer, but the green acid sulfonates are also carried down in this brine layer because apparently they are preferentially soluble in the water of thebrine layer, whereas the mahogany acid sulfonates which remain in the supernatant layer are preferentially solublein the oil and in the oil-soluble solvent. l
The temperature range of 140 F. to 170 F., above indicated, hasthe further advantage that the separation of solvent vapors is small. In practice such vapors as do accumulate in the top of the tank are conducted to a solvent recovery system. Y
After suicient standing and settling, the separated brine layer is Withdrawn from the bottom of the tank. Inthe particular example above given, the brine layer measured 12 gallons at about 140 F., and the soapsolvent layer measured 76 gallons, there being 52 gallons of oil which was rejected. Preferably the withdrawn brine is passed to a still and the dissolved solvent driven `off and recovered.
Concentration stage-If further concentration is desired, the above described soap layer containing the oil, solvent, and mahogany soap is passed from the tank 12 through a heater 14 and upon its way to the heater is mixed with a quantity of tap water and/ or solvent sufticient to unbalance the previous solvent relationship between the oil, soap, and solvent so that upon further standing and settling any desired proportion of the excess oil in the soap-oil-solvent layer is rejected depending on the amount of water and/ or solvent added. In the speciiic instance water equal to 20% of the original charge of crude stock was introduced. In the heater 14 the soap-oil solvent mixture with the added water is raised to a temperature of about F. to 170 F. as before, and this mixture is then either returned to the tank 12 or passed to another tank 15 as indicated in the ilow diagram, where it is agitated to insure equilibrium being established again.
In the tank 15, the heated mixture is again allowed to stand and settle over night, or for several hours, so that the oil rejected by reason of the change in the solvent relationship separates as a supernatant layer above a soap-oil concentrate containing the solvent and the water. In the example described above, where the crude stock contained 74.5% oil, approximately 90% of the oil in the crude stock was rejected into the supernatant layer, while 10% of the oil in the charge remained in the underlying soap layer. In effect, oil appears to be rejected under a given set of conditions until the ratio of soap to oil in the soap containing phase satisfies the equilibrium requirements for that set of conditions (appatently without regard to the quantity of oil in the original charge of stock). Obviously, if the proportion of oil to soap is already below the equilibrium requirements, no oil will be rejected under that particular set of conditions. As more water and solvent are added,
-however, a point will be reached where oil will be rejected. We have thus been able to concentrate alkali sulfonate to a degree where only 22 parts of oil remained for each 78 parts of sulfonate.
Conversion stage-The aqueous soap concentrate (containing the solvent and some oil) which settles out in the tank 15 is next subjected to treatment to convert the alkali-metal, water-soluble, oil-soluble, mahogany sulfonate into a water-insoluble, oil-soluble, polyvalent-metal takY'ISt'oV a heater 16 forest-ore Vits"'temper"attir, and by comniiiigliiig thisconcentrate-with a water solutin'r'f an appropriate polyvalent-metalsalt. Commonly, calcium su'lfonat'es are produced, and y'for this 'purposea 10% to 40% solution of calcium* chloride in Water is mecd, this soli1`tion-be'ingv commingled Awith the soap-oil concentrate Vasfit'is passed 'to the4 heater 1-6 whereby to raise thetemfonate concentrate in: foil' together with the b'ulkof the solvent-randalim'ited arrniuntofv entraine'cl or 'dissolved wa'terk Inr operatin'gfwith theforiginal `100 gallons of crude sulfonate of Vthelahove example, the Vamount Vof calcium ohlolnide used to convert the mahogany sullfonate in the concentrate-was about pounds'which was dissolved in about eight gallons' of water.` A
In order to provide a consistent control of the concentration of the'sulfonate 'in theend'product, it has been found `both'easy and desirable to' vreject more 'oil than necessary durin'gthe rejection operation and then add vback an'appropriate amount of thesame or anothermore desirable oil at a later'st'ageto regulate the soap: concentration inthe .inalproduct` Where the concentrated sodium sulfonatefisto be converted to a polyvalent'metal sulfona'teytheconcentration adjusting oil may be added before,'during, or after the conversionto the polyvalent^ metal 'sulfonate In the above example, a portion of the rejected oil phase was pumped intoV the conversion tankl following the transfer of the'concentra'ted sodium sulfonate phase to the conversion tank 20.
Normally, int-he conversion-stage'it might be expected that,-in View of past experiences, the calcium or other polyvalent-metalsulfonate formed in such concentrated oilsolution wouldv result in the production of a very refractory water-in-oi1'emulsion. However, in conjunction with the described emulsion-breaking organic-'liquid solvent,` the phases' break readilyan'd separate sharply -in the tank` 20 within' a lfew hours to' yield an-underlying brine layer'of sodium chloride and calciumchloride-in water with a sharply'denedlsupernatantlayer-of polyvalentmetal soap iri'concentrated condition'intth'e oil pres'- entytogethe'r with the -bulkof the emulsionlbreakingliquid used anda proportion-of water which is readily removable during a subsequent:dehydrationI step;k We havel no particular theoryregarding the actionA of the indicated class of organic compound; Apparently the functionfof the emulsiombreakingliquid, is not sov much that of a selectivesolventas that of breaking up anotherwise stable oil-continuous emulsion-,or, possibly that of preventing formation Yofsuch an emulsion.
The calciumsoap-oil-solvent layer` is then passed toa still 22 to distill ol the solvent, which is recovered and Sent to storage, and to'dehydrate the oil-soap concentrate to yield a finished productwhich may be placed in storage, as in a receptacle 24, either `with or without ilte'ring or other further treatment.
Inasmuch las'the-excess'oil 'rejectedv in thev concentration Vstageintank 15 may contain Va very small amount of mahoganysoap, this soap should be converted intocalcium'or other polyvalent-metal soap.- Therefore, such oil, having beenVv passed for 'example to the tank `1S for treatment, is recirculated'through a heater ZS'in ad'rriixture' with the'excesscalcium chloride in the'watei solution draWnfroni-the conversion tank `20, andthe temperature l0 agibeghttilt inserimento '170 F. The heated mixture is allowed to s'tandinthe tanl; .'iuntil thelwater solution "separateswin'l thefbottorn and leaves V'ai supernatant oil layercontaining thesm'all amount of resultant calcium sulfonate.- Suchoil; whichds'commonly of lubricating viscosity, isuseful'in lubricating, rust`preventing,v and other petroleum compositions Iand is therefore dehydrated and recovered asV a valuable product.
calcium sulfonate concentratehaving a sulfated ash value of 7% to 8% may be obtained, and a yield of by-product (rejected) oil havingra sulfated ash value of about 0.02% to 0.10% maybe obtained. i
Referring tovarious` aspects of the above-described treatmenn'nthe purification step the dosages of water (or NaCl solution) and emulsion-breakingliquid are Vbest selected* with respect to each other. it is apparent from Fig.- 2 that, for eachy solvencdosagein thelrange of 5% to 15% basedV on theoil-soap'content of the stock, Vthere is :inappropriate range'of water content of the mix (the sumV ofbotlrthe water present inthe stock and the water added) for any given solvent content. This appropriate water contentof the mix will usually be found in the range' of 10% to 60% Water based on `the oil-soap content of the stock. Furthermore, in the appropriate water range foriany given solvent dosage, there will be a somewhat narrower preferredrrange of water content, as is to be Vexpected rfrom the fact that'with water contents, below and above the app'r'opvriateI range, no Vbrine phase is produced. For exampleya methyl ethyl ketone dosage of 10 parts and a total-water content of 27.5 parts (20 parts added -j- 7.5 parts'in the stock) per 100 parts of stock gave about the same extraction of salts and other impurities (such as green lacid soap) as a ketone `dosage ofi-20 parts and a total water content of 47.5 parts. In the first case the yieldv of brine layer was 12 parts as corn'- pared with 15 parts in 'the`second, but the vbrine in the first case was more concentrated. (Other crude sulfonates will have somewhat different optimum ranges'but the appropriate range will be found Within the'general order of magnitude indicated Ifor the stock shown above.) While the extraction ofY impurities was about the same in the two cases, it -willbe noted that in the rst case only a brine phase separated on settling,'leaving a soap-oil layer orf 118 parts,` whereas in the second case a rejected oil layer (61 parts) appeared on top of the concentrated and puried soap'layenthereby making three layers. Sometimes` Vit'is preferable toL avoid simultaneous rejection of oil along with thebrine, as for example in one method of operating a continuous extraction column, but in the batch method, simultaneous separation of oil is of little consequence, and the dosages of solvent and water are chosen to give the optimum extraction of salts and other watersoluble impurities regardless of simultaneous rejection of oil from the soap phase.
In the event sucient oil is rejected under conditions of optimum extraction of water-soluble impurities, then subsequent rejection of oil is obviously unnecessary and the concentration step istherefore completed along with the purification; On the other hand, if the purification conditions chosen do not reject the desired proportion of oil, then the brine phase is removed'and additional water is then added to bring up the vtotal water used (including water originally in the stock) to the place on the curve where the'desired amount of oil is rejected. Instead of adding water, morel solvent, or both solvent and water, may be added to cause additional rejection of oil. If the purificationand concentration are to be conducted sepal rately, thebrine'settled in the' purification step should be to 50% based on the oil-sulfonate content.
- 11 removed before any appreciable additional water or solvent is added, lest the brine redissolve in the mix.
Often, it is desirable to have present at least enough solvent to saturate or approximately saturate the water present, in order to get good separation. This is true especially where high volume ratios of water (such as higher than the indicated 60% of water based on the oil-sulfonate content) are used, inasmuch as such saturation provides a good means for solvent control. Otherwise, good solvent contents are found in the range of 10% to 50% of the total water content, or within a range of about The economically and operatively preferred range, if not the most eticient range, is from to 40% of the solvent or emulsion-breaking liquid, based on the oil-sulfonate content.
In the event the crude sulfonate as received contains too much water to give a brine phase upon the addition of the speciiied solvent, the excess water is removed by evaporation substantially in toto or, if desired, until the amount remaining corresponds to the working range for the usual solvent dosage of 10% to 35%. The evaporation may be by `distillation or by heating and air blowing. In general the most satisfactory procedure is to remove most of the water and then add back the desired amount as the stock is processed in accordance with this invention.
-In purifying crude sulfonates containing 4a high ratio of soap to oil, it has been found convenient and etiicient 4to add a substantial amount of lubricating oil to the stock or to the mix being treated for the two-fold purpose of reducing the viscosity and reducing the solvent power of the soap phase for Water-soluble impurities. As long as the oil added is of suitable quality, this entails little or no hardship because this amount of oil is easily rejected, after the removal of the brine layer, by addition of water or solvent and thereby recovered. In this instance the rejected oil may be recycled without removal of dissolved or entrained solvent and water.
In the foregoing example of a commercial operation of the process, the method of treatment is batchwise for each of the purification, concentration, and conversion steps. In many instances, however, particularly where the demand for the finished sulfonate is steady and of sufficient magnitude, it is desirable to operate the process in a continuous manner.
Figure 3 illustrates continuous operation of the process with single stage treatment by the reactants. Pig. 4 illustrates continuous operation of the process with countercurrent iiow of reactants. Many moditications and conrbinations of the steps will be readily apparent to those skilled in the art from the disclosures contained herein. For example, multiple treatments may be given at each step of the process of Fig. 3, when necessary to obtain complete results.
Referring to Fig. 3, the crude sulfonate in a storage tank 31 is fed by a pump 32 at a controlled rate through a line 33 to the processing system. The emulsion-breaking liquid solvent specified herein is charged at a controlled rate lthrough a pump 34 into the line 33 through which the crude sulfonate is owing. Water or aqueous sodium chloride solution is charged through a pump 35 at a controlled rate also into line 33 through which the crude sulfonate and solvent are flowing. The mixture of crude sulfonate, solvent and water flows into a mixer 36 which is equipped with suitable agitators and bafes to insure chemical equilibrium of the reactants and reaction products as they emerge from the top of the mixer 36 -through a line 37 and iiow into a settling vessel or purifier 3S. In this vessel, the soda brine phase containing sodium sulfite, sodium sulfate and other water-soluble impurities, such as green acid soap', settles to the bottom and the purified sulfonate rises to the top. The settled soda brine is withdrawn through a valve 39 actuated as by a suitable liquid level control device (at Ithe interface) in vessel 38 and sent to a solvent recovery still where the solvent is recovered, and the brine is then discarded.
The purified sulfonate practically free of brine droplets overows from the tank 38 to a line 40 through which it is forced by a pump 41 into a mixer 42. Water is charged by Va pump 43 into the line 40 through which the purified sodium sulfonate is owing. Mixer 42 is equipped with suitable agitators and bafes to insure equilibrium between the reactants and reaction products by the time they emerge through an upper line 44 and flow into a settling vessel or oil rejector 45. The mixture entering the vessel 45 stratities into a concentrated soap and oil layer settling to the bottom and a rejected oil layer rising to the top and removed through an upper line 45a. The concentrated soap layer is transferred from the bottom of the vessel 45 through a lower line 46 by a pump 47 and a valve 48 which are controlled by a suitable liquid level device 'in the settling vessel 45. A relatively concentrated calcium chloride solution is charged by a pump 49 into the line 46 through which the concentrated sodium sulfonate is owing, this stream passing to a converter or mixer 50 equipped with suitable agitators and baflles to insure thorough equilibrium between the reactants and reaction products when the mixture emerges at the top through a line 51 by which it is carried into converted concentrate settling vessel SZ. The mixture entering the settling vessel 52 straties into two layers; namely, (1) an aqueous phase containing sodium chloride formed by metathesis from the calcium chloride, excess calcium chloride, and other water-soluble impurities such as the last portions of green acid soaps, and (2) an oily phase consisting of oil, converted sulfonate, and the major portion of the solvent carried through the process to this point.
The oily phase rises to the top of the settling vessel 52 and overilows through a line 53 from which it is charged by pump 53a to a solvent recovery still 54. A slurry of calcium hydroxide in either oil, Water, or calcium chloride solution is prepared in an agitator 55 and pumped via a line 55a and a pump 56 into the line 53 carrying the converted soap layer to the solvent recovery still 54. In practice the still 54 is duplicated, one still being used for distillation while the other is being charged, or the converted soap layer supplied by the line 53 is accumulated -in an intermediate storage tank (not shown) while a batch is being run down in the still 54, or the still 54 may be of the continuous type consisting of a tubular heater and fractionating tower. Either steam or vacuum or both may be used in the still to aid removal of the last traces of solvent 'and water from the converted soap layer. The converted soap layer is nally heated to a temperature in the neighborhood of 300 F. and then filtered in a filter press 57 and sent to storage 58. To aid filtration of the dehydrated calcium soap concentrate, a small amount of diatomaceous earth (e. g. Supercel, Hyo), such as 1% to 2% by weight, is added before filtration. The solvent from the converted soap layer is recovered in apparatus 59 for reuse in the process.
Inasmuch as the process depends upon the presence of Water in the various steps, it is usually unnecessary to remove the dissolved water from the solvent recovered from any step in the process. The water layer from the condenser of the solvent recovery system is occasionally rerun to concentrate the solvent.
Since the rejected oil layer rising in the settling and oil-rejecting vessel 45 contains a small amount of sodium mahogany soap which should be converted, such oil is passed by the line 45a from the vessel 45 to a mixer 60 equipped with suitable agitators and baffles to insure equilibrium between reactants and reaction products. Since therbottom aqueous layer in the settling vessel 52, resulting from thereaction of the concentrated soda soap with calcium chloride solution, contains excess calcium chloride, this brine layer also is pumped to the mixer 60 for the purpose of reaction with the soda soap in the rejected oil. This transfer is made by way of a line 61,
arenaria by a pump 60a. Followingareactlon betwe'eirf'calcim chloride and the sulfonate oftherejected toil'in theA mixer 60, the reacted materials leave themixerl 60 4byaline 62 and flow Vinto aV settling ve'sseli63fwhe`re stratification occurs tol yieldffa calcium brine. layer .-'onthefbottomi and a converted oil layer on topa` The converted oillayer is delivered by aline 64and a fpumpfiagto a still 65 for recovery of contained solvent; and, dehydration of;the.oil. The calcium brine layer is withdrawn from 'the Abottom of the vessel 63- throughtvsuitableglevel-,controllvalvesf-and pumps (not shown) and is processed'for recovery-of4 dissolvedsolvent and-then discarded.- A- small portion of this brine can be used infftheE agitatorSS, if desired; in making `a calcium hydroxidel slurry-to-be added Yeither to the concentrated soapalayenbeing ,chargedto the still 54 or to theconverted, rejectedV oilflayer' charged 'tothe still 65. The converted by-,productoilwlayen in` which anytrace of soap carried over fromnthevconcentration of the soda soap `in the` settlingand rejectingvessel 45 `has now been converted in the vessel .63 to'calciumsoap,
when being processed in the still 65 may contain a slurry of calcium hydroxide suspended inl oil or water or brine containing calcium chloridel added from theagitator 55,V as ab'ove indicated, or from an agitator 66 by a pumpt67 via aline 68, to the charge goingtinto the still 65; Irv-this still, both dissolved solvent'A and -water areV removed 'by heating to atemperature in' the neighborhood of SOO'VF. with the useof vacuum` or steam. The liberated `solvent is recovered in appropriate apparatus A69-` for reuse -in the process. The dehydrated solvent-'free oil` isfiil'teredl-and sent to storage'70 Vfor usen blending lubricatingoils-rust preventives, and the like,orit may be`fur'ther'relniedto produce white oils.
In theoper'ation illustrated in'Fig. 3, the temperature is'preferably higherthan in the'batch method illustrated in Fig. 1, to insure ecient operation of thecontinuous settling vessels; namely, in the neighborhood of `l60 F. to 200 F. aspreviously indicated.' Appropriate heaters (not shown) are^employed in much the' same way as shown in Fig. 1. Care is taken to avoid loss of solvent by vaporization, even to the point of operating all mixers and settlers under pressure.
The higher boiling solvents of the disclosed class are often preferred'in the continuousfme'thodof operating the process at the 'higherA temperature, because they are more readily'recovered from the various brines and products with less vapor loss. Higher temperatures, e. g. 160 F. to 200 F., withL operation under pressure are employed in such countercurrentV operationslin much the sameV manner as for the process of Fig. 3.
Figure 4 illustrates a countercurrent, continuous operation of1 the process, the crude sulfonate in storage tank Y 71 being fed by Ia pump 72'at a controlledrate through a line 73 to the processingsystem. TheV emulsion-breaking liquid solvent specified herein is charged'ata controlled rate by1a pump 74 into the line 73 through whichv the crude sulfonate is flowing. The mixture of stock and solventi enterstthe lower portion of acountercurrent extraction column 75 whilewater or aqueous sodiumchlo-V ride is charged at a controlled rate by a pump 76 and a line 77 into the upper portion of the extraction column 75. As the mixture'ofstock and solvent works its way up the column, the water or` sodium chloride solution works its way downward and extracts from the stock the water-soluble impurities such as sodium sulfate, sodium sulte and the green acid soaps. The brine thus formed settles in the bottom of the column 75 and is withdrawn .through a valve 78 which is actuated by a suitable level control in the column 75 and is sent to a still for recovery ofthe `solvent dissolved therein.. The extracted'or` purilied stock containing the bulk of the solvent introduced into the stream of stock in the line 73, passes out of the top fof: the columnfr75" through'ialineE and'1 is forced by'a pump throughffa.l line` 8i eitherfdirectlv into' aufoil rejection or extension column 82 or via an agitator 83 by proper'manipulation offv'alves' 84, Vt' 'f,and S62 Water Vis charged into thesystemat-'a'controlled rate by a pump SSthrough a line 39 by opening a valve 90, and/ or water essed. Sometimes it is desirable to introduce all of -the water via the pump 91 and Vline 93 Vinto :the top section of the column 82, in which case the stock flowing in the vline 81 is made to'bypass Vthe agitator 83 by opening the valvel S4 and closingthe ivalves 85 and S6. The water introduced into the topsection of =thevextraction column Y 8`2- via line 93 washes countercurrently the rejected oil which is rising'upward inthecolumnZ, and also causes rejection of oil from the purified stock in the lower section of the column S2.
In l[other words,"v partial or'fairiy complete rejection of oilrnay be accomplished by thewa'ter introduced along with the stockvia the line Slandagitator 83, while any Water introduced" intol vthe upper section of the column SZ'viav the line 93'seives1towash outY soap dissolved or entrained in the rejected oil'rising' from the bottom of the column. p
Thesoda soap solution 'now concentrated with re- 'spect to oil Ysettles to thebott'omof thecolumn $2 .and
is'removed via'agvalve94 anda pump 95 which are actuatedby a suitable level cont'roldeviceV (nofshown.) in the lowest lsection of the column 82.l The concentrated sodafsoa'p solution` is forced by the pump 95 `via Va line A961into the ,bottoml section ofa conversion'or extraction column 97," going through an agitator 98 or by-passin'gthis Yagitatonby proper operation of valves 99",1lll`9,and`101.l Aqueousjcalcium chloride solution of suitable concentrationV is charged into the column.97 by a pump 102 via-a line 103 into the top section ofthe extraction column 97, or'by a pump 104 into the bottorn sectionofrthe column 97 inl admixture with the concentrated soap stock moving `in the line 96. If calcium chloride solution is introduced into the line 96, it is desirable to agitate` the resulting Vmixture thoroughly before it reaches the column l97` by sending it through the agitator 98 by opening the valves'ltlt) and 101 and closingthe valve'99. If a portion of thecalciumichloride solution yis premixed withthe Ystock in the agitator 98 and introduced into the bottomsection' of the column 97, via the 'linef 96 along with the stock, any additional calcium chloride solution introduced bythe pump 102 moves countercurrentto the reacted -oilyy soapy phase risingv in the column 97 and serves to complete the conversion of'sodium'soapto calcium soap.V The converted soap" phase flows out the ltop of'column 97l via'a line 1051 and a pump 106 and is sent tointermediate storage tank 107 whence it is sent to a still-108, for recovery of` solvent-in apparatusx109, and dehydration before filtering.- Lime-or other reagents'may be 'added to the stock in vthe tank 1ll7 before it is charged to the still 108 by a pump 110. Diatomaceous earth which serves asia iilter aid is added before, during, or after'the :distillation and dehydration. The dehydrated concentrate is passed through a lilter 111 and thefinished calcium sulfonate concentrate is sent to storage 1712.
Thespent or partiallyspent calciumchloride brine resulting from the conversion of the soda soap to calcium'` soap inthe agitator* 98 and conversion` or extrac-k tion columnf97,settles tofthe bottom of thecolumn 97, whence it is withdrawn through a'valve 113 Vand pump 114and sent to a still for'recovery of dissolved solvent. A
The oil rejected in the rejection column 82 rises upward and settles practically free of entrained water and 'f soap in the top of the column. However it contains a very small proportion of dissolved mahogany soap which should be converted. Therefore, the rejected oilY is passed from the top of the column 82 via a line 115 and a pump 116 into a treating column 118, Aand calcium chloride solution, which may conveniently be the partially spent brine layer settling to the bottom of extraction columnv 97, also is introduced into the top of column 118 via a pump 119 and a line 120, or into the bottom of the column 118 via a pump 121 and a line 122. Any calcium chloride solution introduced via pump 119 is best mixed with the rejected oil phase flowing in the line 115 by passing the mixture through an agitator 123 before it goes into the treating column 118. The operation of the conversion of the small amount of soda soap carried over in the by-product oil owing from the top of the rejection column 82 is similar to the conversion of the concentrated soda soap phase settling to the bottom of the column 82 and converted and separated in the column 97.
The converted, rejected oil in the column 118 'rises to the top and is sent via a pump 124 and a line 124a to intermediate storage 125, whence it is charged by a pump 126 to a still 128 for solvent recovery in apparatus 129 and for 'dehydration before filtering. VAfter passing through a filter, this converted, rejected oil is sent to storage for use as a lubricant, or in compounding rust preventivas or lubricants, or the like. The brine phase in the column 118 settles to the bottom and is withdrawn via a valve 131 and a pump 132 which are controlled by Ia suitable liquid level device (not shown) in the lowest portion of the column 118. This brine is distilled for solvent recovery and is nally discarded.
It isto be understood that this process, whether batch or continuous, is also applicable to the treatment of alkali-metal or ammonium sulfonate-ol concentrates of commerce whichr contain around 30% to 60% sulfonates and to 70% oil with impurities in the form of green acid soaps, sulfates, sultes, and the like, although this process is particularly adapted to the treatment of sulfonated oils containing the indicated lower soap contents.
It is also to be understood that where a reference to alkali-metal sulfonates is made in this specification and the claims the expression is to be construed as including also the equivalent ammonium sulfonates.
While the purified polyvalent metal petroleum sulfonates or mahogany soaps obtained in accordance with this invention are usually calcium products, the invention, nevertheless extends to the preparation of other alkaline earth metal sulfonates, especially barium and strontium salts. These may be prepared with Watersoluble salts of barium and strontium as readily as the calcium product is produced. The process is also applicable to the production of other water-insoluble, oilsoluble sulfonates, and these may include the mahogany acid salts of aluminum, zinc, magnesium, lead, cobalt, nickel, and the like.
Concentrates of the above nature may be put to various uses. the above concentrate to calcium, aluminum, barium, magnesium, zinc, and lithium base greases, respectively, has both imparted markedly improved anti-rusting properties and reduced tendencies to bleeding or separation of the oil content of the greases on standing.
Rust preventives-constitute another important phase of use of the present product. These are obtained by diluting the appropriate polyvalent-metal sulfonate con- For example, the 4addition of 5% to 20% of centrate with appropriate carriers, such as anyl mineral oil lubricating fraction suitable for the ultimate use of T16 the product; Commonly, such dilution will yield Va sulfonate content between about .05% and about 6% in the blended product. Ordinarily a satisfactory working proportion is abouty 3% of sulfonate, or within a range of'about 2% to about 4%.
Another important use of the puriiied, polyvalent-metal sulfonate of this invention is in connection with the production of lubricating oils for severe service, internal combustion engines, such as aircraft and other heavyduty engines, including diesel engines. Here the sulfonate may be present in proportion to impart rustpreventive characteristics or for other purposes, including promotion of detergent and Wear-reducing characteristics. For these purposes, typical lubricating oils may contain from about 0.5% to as much as 10%, for example 3%, of the purified alkaline earth metal sulfonates of this invention, together with suchother Yadditive constituents as may be deemed desirable. Depending upon t-he ends sought, such other materials may include sulfurized alcohols, sulfurized hydrocarbons, thiophosphates, Zinc dithiophosphates, phenolic thioethers, phosphites, metal derivatives of these materials, various oil-soluble detergent soaps, such as the calcium soaps, and similar metal soaps of synthetic' carboxylic acids obtained from the oxidation of paraiimic hydrocarbons, alkyl phenols, pour point depressors, anti-oxidants, viscosity index improvers, and kindred materials known in the lubricating industry.
I have also found that the presence of 0.25% to 2% of octyl alcohol orother high molecular weight alcohol jin the finished Vlubricant increases very greatly the effectiveness of the sulfonate addition -in combating corrosion from hydrobromic acid. For example, the addition of 2.5% calcium sulfonate to a heavy-duty motor oil containing 0.75% calcium soap of oxidized petroleum acids and 0.75% calcium salt of tertiary amyl phenol sulfide was sufficient to protect the crankcase interior of engines against rusting from moisturetcondensation, but was insufficient to protect against dilute aqueous hydrobromic acid. The addition of 0.75% of octyl alcohol (Z-ethylhexanol) to the foregoing-oil containing 2.5 sulfonate, as described, gave perfect'protection against hydrobromic acid corrosion.
Additional data involving the treatment of crude sulfonate-oil stock with Various solvents of the present class in various amounts is presented in the following table:
KETONE TREATMENT- VOLUMES 0F STOCK 1 Two layers.
While I have described the process as being appli-cable to petroleum sulfonates pro-duced 4by sulfuric acid treatment of petroleum fractions particularly those in the lubricating oil range, the process is also applicable to Asulfonates produced synthetically by sultonation of hydrocarbons or other compounds from coal tar products or any other source. Also, -the process isV applicable to sulfates (oftcn'called sulfonates) produced by reacting sulfuric acid or sulfur trioxide with alcohols and/ or unsaturated compounds belonging to the classes of hydrocarbons, acids, esters, ketones, ethers, glycerides, waxes, etc.
wrefrein-15 which comprises: forminga .mixture consisting essen- Vtially or" saidhydrocarb'on oil, said alkali metal mahogany sullionates, said alkali smeftalgreeniacifd sulfonates, 4said water-soluble'inorganic sulfate and sulte, at least l0 parts by volume ot waiter per 100 'parts Vby Yvolume of said hydrocarbon oil and sulfcnates `and at least 5 Vparts by-volume .per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon voil-soluble emulsion breaking liquid which is a ketone selected from the class consisting of acetone, methyl ethyl ketone, diacetone alcohol, acetyl acetone andacetonyl acetone, the Vamounts of said water and said emulsion breaking liquid 4being suic-ient to produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon oil, water and emulsion-breaking liquid, a hydrocarbon oil phase rejected from said concentrated mahogany sulfona'te phase and an aqueous phase containing alkali metal green acid sulfonates and water-soluble inorganic sulfate and sulhte; and separating said three phases from each other. Y
2. The process as defined in claim l in which the temperature of said hydrocarbon oil phase and said concentrated sulfonate phase during said separating is between 140 F. and 200 F.
3. The process as defined in claim l in which the emulsion-breaking liquid is methyl ethyl ketone. v
4. The process as defined in claim l in which the emulsion-breaking liquid is acetone.
5. The process as defined in claim l in which the emulsion-breaking liquid is diacetone alcohol.
6. The process as defined in. claim l in which a watersoluble polyvalent metal salt is mixed with the separated concentrated `mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor pro.-
portions of Water and emulsion-'breaking liquid and the separable aqueous phase isl separated from said concentrated polyvalent metal mahogany sulfonate phase,
7. The process of treating a material consisting of a major proportion of hydrocarbon oil -containing alkali metal mahogany sulfonates, alkali m-etal green acid sulfonates and water-soluble inorganic sulfate and sulte, which comprises:V form-ing a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said water-soluble inorganic. sulfate and sulite, sodium chloride, at least l0 parts by volume of water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion-breaking liquid which is a ketone selected from the class consisting of acetone, methyl ethyl ketone,
diacetone alcohol,.acetyl acetone and acetonyl acetone,
the amounts of said Water, said sodium chloride and `said emulsion-breaking liquid beingsuicient to 'produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon oil, water and-emul-V sion-breaking liquid, a hydrocarbon oil phaserejected from said concentrated mahogany sulfona'te phase and an aqueous phase containingalkali metal green acid sulfon'- ates, water-solubleinorganic sulfate and sulte and a,
major Vproportion of said sodium chloride; and separating said three phases from each other.
8. The process as ydelned in claim 'I inwhich a waterrsoluble polyvalent metal salt is mixedwth the separated concentrated mahogany sulonate phase .to convert :the alkali metal mahogany sulfonate therein to av polyvalent metal mahogany sulfonate and produce a separableaqueousph-ase and a concentrated polyvalentmetal mahogany sulfonatephase containing hydrocarbon oil and minor maj-or proportie-11 of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali, metal green acid ,sul-k fonates .and Water-soluble -inorganic sulfate and sulte, whichfcomprises: forming armixturetconsistingressentially of .said hydrocarbon oil, Vsaid alkali -metal mahogany sultomates, said alkali metal `green acidsulfonates, -said waterso-luble inorganic sulfate and suliite, at least 10 parts by volume of water per parts by volume of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion-'breaking liquid which is a ketone selected from the class consisting of acetone, methyl ethyl ketone, diacetone alcohol, acetyl acetone and acetonyl acetone, the amounts of said water and said emulsion-breaking liquid being sucient to produce an aqueous phase containing alkali metal green acid sulfonates and water-soluble sulfate and sulte, and a separable hydrocarbon oil-sulfonate phase containinfy hydrocarbon oil, water, emulsion-breaking liquid and alkali metal mahogany sulfonates; separating said hydrocarbon oil-sulfonate phase from said aqueous phase; mixing with the separated hydrocarbon oil-sulfonate phase an additional amount of a liquid selected from the group consisting of Water, and said emulsion-breaking liquid, the amounts of said water and said emulsion-breaking liquid in Ithe resulting mixture being stucient to produce a concentrated mahoganyV sulfonate phase containing alkali metal mahogany sulfonates, hydrocarbon oil, water and emulsion-breaking liquid and a separable hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase; and separating said hydrocarbon oil phase from said concentrated mahogany sulfonate v phase. l
10. The process as dehned in claim 9 in which the emulsion-breaking liquid is methyl ethyl ketone.
ll. The process as dened in claim 9 in which the emulsion-breaking liquid is acetone.
' 12. The process as defined in claim 9 in which the emulsion-breaking liquid is diacetone alcohol.
13. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and `Water-soluble inorganic sulfate and sulite, Which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates,` said Water-soluble inorganic sulfate and suliite, sodium chloride,- at least 10 parts by volume of water per 100 parts -phase containing hydrocarbon oil, Water, emulsion-breaking liquid and alkali metal Vmahogany sulfonates; separa-ting said hydrocarbon oil-sulfona-tc phase from said aqueous phase; mixing with the separated oil-sulfonate phase an additional amount of a liquid selected from the group concentrated mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of water and emulsion-breaking liquid and Vthe separable aqueous phase is separated from said concentrated ,polyvalent metal mahogany sulfonate phase.
15. The process as defined in claim 13 in which the emulsion-breaking liquid is methyl ethyl ketone.
16. The process as defined in claim 13 in which the emulsion-breaking liquid is acetone.
17. The process as defined in claim 13 in which the emulsion-breaking liquid is diacetone alcohol.
References Cited in they file of this patent UNITED STATES PATENTS 1,901,383 Voogt Mar. 14, 1933 2,084,506 Rosen June 22, 1937 2,168,315 Blumer Aug. 8, 1939 2,522,212 Dammers Sept. 12, 1950

Claims (1)

1. THE PROCESS OF TREATING A MATERIAL CONSISTING OF A MAJOR PROPORTION OF HYDROCARBON OIL CONTAINING ALKALI METAL MAHOGANY SULFONATED, ALKALI METAL GREEN ACID SULFONATES AND WATER-SOLUBLE INORGANIC SULFATE AND SULFITE, WHICH COMPRISES: FORMING A MIXTURE CONSISTING ESSENTIALLY OF SAID HYDROCARBON OIL, SAID ALKALI METAL MAHOGANY SULFONATES, SAID ALKALI METAL GREEN ACID SULFONATES, SAID WATER-SOLUBLE INORGANIC SULFATE AND SULFITE, AT LEAST 10 PARTS BY VOLUME OF WATER PER 100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES AND AT LEAST 5 PARTS BY VOLUME PER 100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES OF A HYDROCARBON OIL-SOLUBLE EMULSION BREAKING LIQUID WHICH IS A KETONE SELECTED FROM THE CLASS CONSISTING OF ACETONE, METHYL ETHYL KETONE, DIACETONE ALCOHOL, ACETYL ACETONE AND ACETONYL ACETONE, THE AMOUNTS OF SAID WATER AND SAID EMULSION BREAKING LIQUID BEING SUFFICIENT TO PRODUCE THREE SEPARABLE PHASES, A CONCENTRATED MAHOGANY SULFONATE PHASE CONTAINING HYDROCARBON OIL, WATER AND EMULSION-BREAKING LIQUID A HYDROCARBON OIL PHASE REJECTED FROM SAID CONCENTRATED MAHOGANY SULFONATE PHASE AND AN AQUEOUS PHASE CONTAINING ALKALI METAL GREEN ACID SULFONATES AND WATER-SOLUBLE INORGANIC SULFATE AND SULFITE; AND SEPARATING SAID THREE PHASES FROM EACH OTHER.
US442599A 1954-07-12 1954-07-12 Method of purifying, concentrating, and converting petroleum sulfonates with ketones Expired - Lifetime US2781315A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4579690A (en) * 1984-12-28 1986-04-01 Shell Oil Company Process for the deoiling of olefin sulfonates
US20070185219A1 (en) * 2005-12-21 2007-08-09 Jean-Francois Argillier Method of Breaking Aqueous Heavy Crude Emulsions by Adding Polar Solvents

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1901383A (en) * 1930-03-31 1933-03-14 Shell Dev Process for recovering the oil-soluble sulphonic compounds formed in the acid refining of mineral oils
US2084506A (en) * 1937-06-22 Process fob preparing improved
US2168315A (en) * 1937-01-19 1939-08-08 Soneborn Sons Inc L Method for the purification of petroleum mahogany sulphonates
US2522212A (en) * 1946-12-19 1950-09-12 Shell Dev Concentration of aqueous solutions of hydrocarbon sulfates and sulfonates

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2084506A (en) * 1937-06-22 Process fob preparing improved
US1901383A (en) * 1930-03-31 1933-03-14 Shell Dev Process for recovering the oil-soluble sulphonic compounds formed in the acid refining of mineral oils
US2168315A (en) * 1937-01-19 1939-08-08 Soneborn Sons Inc L Method for the purification of petroleum mahogany sulphonates
US2522212A (en) * 1946-12-19 1950-09-12 Shell Dev Concentration of aqueous solutions of hydrocarbon sulfates and sulfonates

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4579690A (en) * 1984-12-28 1986-04-01 Shell Oil Company Process for the deoiling of olefin sulfonates
US20070185219A1 (en) * 2005-12-21 2007-08-09 Jean-Francois Argillier Method of Breaking Aqueous Heavy Crude Emulsions by Adding Polar Solvents

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