CA1144177A - Refinement of sulfonated hydrocarbons - Google Patents

Abstract

REFINEMENT OF SULFONATED HYDROCARBONS
Abstract In a process for the production of sulfonated hydro-carbon, e.g., a petroleum fraction and crude oil, enhanced separation of the unreacted hydrocarbon from the sulfonate product is obtained by two separations. The acidic product obtained from the sulfonation of the hydrocarbon is subjected to an incomplete separation from the unreacted hydrocarbon wherein from about S to about 15 percent by volume of the free unreacted hydrocarbon is retained in the product.
Thereafter, the product is neutralized and subjected to a final separation in which the remainder of free unreacted hydrocarbon is removed from the sulfonated product.

Description

Descri~tion RE~INEMENF 0~ SULFONATED HYDP~OCARBONS
. ... . _ Techn~cal Field This invention relates to the sulfonation of hydro-os carbons, e.g., petroleum fractions and cxude oils, and, more specifically, to a process for the separation of unreacted hydrocarbons from the final sulfonate product.

Bac~round Art Prior Art Statement .. . . ... . _ ...
Single extraction of unreacted hydrocarbons from petroleum sulfonates is well known in the art, fox example, U.S. 3,493,048 and U.S. 3,504,744. Re. 22,548 to Brandt uses water to cause the separation of aqueous sulfuric and sul-fonic acids and then uses sodium chloride to extract these acids from organic sulfonic acids. Thereafter, ~.he or~anic sulfonic acids are neutralized. Brandt also discloses the use of solvents such as ethyl alcohol, dioxane, acetone, et cetera, in the extraction process.
Gale, et al. in U.S. 3 ~ 653 r 437 teaches a sin~le solvent 20 process for the removal o unreacted oLls from neutralized petroleum sulfonate surfactant mixtures. Isopropyl alcohol is the prefexred solvent of &ale's process. The art also discloses the extraction of unreacted hydrocarbons from ~ petroleum sulfonates either prior to or after the neutra-25 lization of the sulfonates, e.g. U.S. 4,144,266. Extraction solvents of water, alcohol, low molecular weight hydro-carbons or mixtures of these are generally preferred.
However, the single extractions of unreacted oi' taught by the prior art are incomplete in that ovex a 30 period of several weeks additional unreacted oil of up to about 4 percent will separate from the sulonate product.
The presence of this unreacted oil adversely affects the filterability of a slug containing the sulfonate, e.g., a 114~177 micellar dispersion, which is used in an oil recovery process.
It is an object of the present invention to effect a complete separation of free unreacted hydrocarbon from the sulfonate bv a two step separation process. Not only does this improve the filterability of a slug containing the sulfonate which is used in an oil reeovery proeess and result in a savings through the recovery of valuable oil, but as a result of the incomplete initial separation of the present process, additional savings are realized through a decrease in settling times and size of settling tanks required for a two step separation.
Disclosure of Invention Sulfonated h~tdrocarbons are refined in a two step separation process to remove unreacted hydrocarbons. First, the acidie hydrocarbon sulfonate is subjeeted to a partial separation from the unreaeted hydroearbon wherein the aeidie hydroearbon sulfonate phase retains from about 5 to about 15 pereent by volume of free unreaeted hydroearbon. Thereafter, the aeidic sulfonate is neutralized and the remaining free unreaeted hydrocarbon is separated from the hydroearbon sul-fonate produet. If, during the initial separation, a oomplete separation is obtained between the aeidie hydroearbon produet and the free unreaeted hydrocarbon, then a portion of the unreacted hydroearbon should be readded to the acidic sulfonate prior to the neutralization step in order to obtain a product eontaining from about 5 to about 15 pereent free unreaeted hydrocarbon~ The presence of some raffinate in the sulfonated product after the first separation is necessary to reduee the separation time needed to separate the neutralized sulfonated produet fro~ the free unreacted hvdrocarbon.

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1~4~77 According to a specific aspect of the invention there is provided in a process for the preparation of petroleu~
sulfonates comprising contactin~ sulfur trioxide with a hydrocarbon selected from the group consistin~ of crude oils, topped crude oils, gas oils and mixtures thereof in a reaction zone at a temperature of from about 27C to about 121C and a pressure of from about 0.01 to about 150 atmospheres for a reaction time of from ahout 0.001 to about 3600 seconds wherein from about 5 to about 30 kilograms of sulfur trioxide are contaeted with each 100 kilograms of hydrocarbon, the improvement comprising: (a) allowing the sulfonate product mixture to separate into a free unreacted hydrocarbon phase and an acid sulfonated product phase; (b) separating the sulfonate produet mixture into a phase containing a portion of the free unreacted hydroearbon and an acid sulfonated product phase eontaining the remainder of the free unreacted hydrocarbon sueh that the remainder of free unreaeted hvdrocarbon eauses a faster separation between unreacted hydrocarbon and neutralized sulfonate product than is possible if a complete separation were effeeted between the free unreaeted hydroearbon and the sulfonated produet mixture to be neutralized; (e) neutralizing with a base the acid sulfonated produet mixture eontaining the remainder of the free unreaeted hydrocarbon of step (b); and (d) thereafter removing all of the free unreacted hydrocarbon from the neutralized sulfonated product mixture at a rate of from about 0.3 to about 0.6 hours per foot of emulsion.
Aeeording to a further speeifie aspeet of the invention there is provided a process of enhancing the separation of unreaeted hydrocarbons from the sulfonated product mixture -2a-.~ ,.... , ,~, cb/~\

~btained by contacting about 5 to about 30 kilograms sulfur trioxide per lnO kilograms of a hydrocarbon selected from the group consisting of crude oils, top crude oils, gas oils and mixtures thereof in a reaction zone at a temperature of from about 27~C to ahout 121C and a pressure from about 0.01 to about 150 atmospheres for a reaction time of from about 0.001 to about 3600 seconds to form a sulfonated product mixture from which a raffinate comprising free unreacted hydrocarbons separates, the method comprising the steps of: (a) removing a portion of the raffinate thereby leaving the remainder of the raffinate with the sulfonated product mixture; (b) neutralizing with a base the sulfonated product mixture containing the remainder of the raffinate to form a neutralized sulfonated product mixture and a second raffinate; and (c) thereafter removing the second raffinate from the neutralized sulfonated product mixture, the remainder of the raffinate in step (a) being in an amountsufficient to enhance the separation rate of the second raffinate and the neutralized sulfonated product mixture thereby enabling the removing of step (c) to take place at a rate faster than that which would take place if substantially all of the raffinate has been removed prior to step (b).
The preferred extraction solvents are water and low molecular weight aqueous alcohols.
The process of the present invention is particularly useful in the production of crude oil sulfonates. While 2b-.A, cb/~

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such sulfonates produced by this invention are intended to find their primary use in oil recovery processes, they, or fractions thereof, are also useful in other known appli~
cations of sulfonates, such as flotation, cutting oils and S insecticide carriers.

Brief Description of Drawings Figure 1 is a schematic representation of the process of the present invention..
Figure 2 is a graphic representation of the settling time o~ the neutrali2ed sulfonate as a function of retained raffinate.

_st Mode for Carr~ing Out the Invention The process of the present invention is applicable to any process for the sulfonation of hydrocarbons wherein unreacted hydrocarbons are present. It is especiàlly bene-ficial when mixed hydrocarbons, such as crude oil, aresulfonated to produce petroleum sulfonates. The term crude oil as used herein includes whole crudes, crude oils which have been "topped" to remove the lighter ends having boiling points below about 150 C and preferably below a~out 315 C
and mixtures of whole and topped crude oils. The crude oils may be pure hyarocarbons or may contain sulfur, halo~en and nitrogen moieties. Preferred crude oils are those with aromatic or olefinic portions having molecular weights in the range of from about 200 to about 1,000, preferably from about 300 to about 800 and more preferably about 350 to about 500. The percent aromatics and ole~ins in the crude oil is preferably from about 10 to about 95, more preferably from about 20 to about 80 and most preferably from about 25 to about 50 weight percent.
Sulfonation reactoxs which are conventionally utilized in proce ses for the sulfonation of hydrocarbons including, for example, the falling of film, scraped.surface and stir-red tank xeactors, may be used in the process of this inven-tion. In those instances where a sulfur trioxide diluent is . . .

li.4417'7 .!

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used,, a back mixed tubular reactor is preferred and the materials introduced into the tubular reactor should he in turbulent flow.
It is preferred that an anhydrous sulfur trioxide feed 05 that is free oE impurities such as sulfuric acid, which can cause deleterious side reactions, be used~ From about 5 to about 30, preferably from about 7 to about 2Q and more preferably from about 8 to about 15 kilo~xams o~ sulfur trioxide is fed into ~he sul~onation reactor per 100 kilo~
grams o~ crude oil. The sulfur trioxide can be either a liquid or vaporized state; however, the vaporixed state is preferxed.
The sulfur trioxide can be diluted with liquid or gaseous low molecular weight aliphatics, sulur dioxide, air, nitrogen or other inert gases. Examples of liquid diluent solvent include, ethy1ene dichloride, txichloro-ethylene, nitrobenzene and similar substantially inert polar solvents. These are introduced into the sulfonation xeactor to dissolve the sulfonic acids in the unreacted hydrocar-~0 bons. The desirability of a specific diluent is c~penden~upon the reactivity of the crude oil being sulfonated.
Heavy viscous crudes, such as gas oils, o~ten re~uire a diluent while less-viscous crudes can be sulfonated with or without a diluent. A preferred diluent for less viscous crudes, e.g., whole crude oil, is recycled sul~onic acids from the sulfonation reactor which contains su~fur dioxide and light hydrocarbons.
Generally, the diluent solvent is used in a concen-tration of from about 0 to about 20 kilograms, preferably from about 1 to about 10 kilograms and more preferably from about 3 to about 8 kilograms per kilogram of su~fur tri-oxide. Except when the diluent is a sulfonic acid, it is preferred that the reaction solvent be removed, e.g., by steam stripping, prior to the separation o~ any unreacted hydrocarbons from the sulfonated hydrocarbon.
The reactor conditions are not narrowly critical. The temperature will normally be in the rang~ of from about ~144~7 27 C ~o abou~ 121 C, pre~erably from abQUt 38 C to about 93 C and more preferably from about 55 C to about 82 C. Pressures will range from about 0.01 to about 150, preferably from about 0.15 to about 75 and moxe preferably 05 from about 0.2 to a~out 5 atmospheres. The xeaction times will be from about 0.001 to about 3600, prefexably ~rom about 0.01 to about 360 and more pre~erably from about 0.02 to about 60 seconds.
Additional materials can be introduced into the sul-fonation reactor~ These include known catalysts which ~onot appear to be needed but may be used i~ desixed, and sulfonation additives which, inter alia, may aid in control ling the equivalent weight distribution of the product mixture. ~he additives are useful in amounts xanging rom about 0 to about 20, preferably from about l to about 15 and more preferably from about 2 to about 20 kilogxams of addi-tive per 100 kilograms o crude oil feed stock. The addi-tives are of~en sulfonated or sulfated and become a compo-nent of the product mixture. The additives are i~corporated in the feed stocks beore or auring sul~onation.
Useful additives include aromatic hydrocarbons, ole-finic hydrocarbons, or oxygenated hydrocarbons and pre-ferably have molecular weights in the range of rom 20~ to about l,OOO, more preferably from about 300 to about 800 and 2S most preferably 350 to about 500. Specific examples of additives include oxo alcohol bottoms which are describea by Hatch~ L.F., Higher Oxo Alcohols, Enjay Co., Inc. 1957 and .
ndustrial and Engineering Chemistry, Vol. Sl, No. 3, pp.
257-258; oxo alcohols alkylated with from about 1 to about S0 moles of alkylene oxides, such as ethylene or propylene oxide; catalytic cycle oil axomatics, see ~.S.3,317,44~; and ultraformer polymer bottoms which are mixtures o~ alkylated benzenes and asphaltenes.
After the hydrocarbon is sulfonated, it ;s prefexrea that the water be added to the acid sulonate product mix-ture in order to expedite the separation ~etween the aci~
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1~44~77 ~6-sulfonates and unreac~ed hydrocarbons. Water is added in an amou~t o from a~out 0.1 to a~out 3.0, preferably from about 0.3 to a~out l.S and more preferably from about 0.6 to about 1.O kilograms per kilogram of the acid su~fonate product 05 mixture. T~ereafter, the water and acid sulfo~ate product mixture is permitted to settle until the acid sulfonate phase contains from about 5 to abou~ 15 percent b~ volume o free unreacted hydrocarbon.
After the separation has taken place, the xaffinate is separated from the sulfonic acids. The resultant sulfonic acid mixture mus~ contain from about 5 to about 15 percent of raffinate If the separation is more complete, then raffinate should ~e readded to the acid sulfonate mixture to obtain a mixture containing from a~out 5 to about 15 percent raffinate. q~he presence of greater or lesser amounts of xaffinate will not prevent the complete se~aration of raf-finate rom ~he sulfonated product; however, more time wi~
be required for the second separation.
The thus partially xefined sulfonic acid mixture is then neutralized with sufficient base, prefexably a mono valent base, such as sodium or potassium h~dxoxide or a~mo-nia, to form a neutralized pe~roleum sulfonate. Additional water can be added during the neutraliæation process, as or example, when it is used as the carrier of the neutralizin~
2S agent.
After neutralization to obtain petroleum sulfonate, the petroleum sulfonate mixture is allowed to settle to effect the separation bet~een the remaining raffinate and the petroleum sulfonates. The raffinate is then remo~ed from the sulfonate pxoduct. No further separation of unreacted -oils from the petroleum sulfonates will thereafter occur.
The ~mount of time required for each of the separations of the present refinement pxocess i5 depen~ent upon several parameters, for example, size of the settling tank, ~mount of product being subjected to the process, temperature, and ` 1144177 amount of unreacted hydrocarbon. The amount of unreacted hydrocarbon is affected, for example, by the composition of -the feedstock'sulfonated' and the amount of sulfur trioxide used in the sulfonation process. Since the interaction of 05 these parameters are'understood by those skilled in the art, the amount of time for each separation in a given pxocess is readily determined by one skilled in the art. Gener~lly, the first partial separation of the acidic product ~;- 1 take from'about 1 to about 2 hours per foot of emulsion. The time required for the second separation will be a~fected by the amount of raffinate the neutralized product contains. When from about 5 to about 15 percent by volume raffinate is present, the second separation will generally take from about 0.3 to about 0.6 hours per foot of emulsion.
The separation of the unreacted hydrocarbon from the 'sulfonate can be done as a batch operation or as a conti-nuous'operation.
Xf the hydro~arbon feedstoc'~ contains wax, then kero- -sene may be added to the partially separated acidic sul-fonate prior to the neutralization of the acidic sulfonate.
The ~erosene is added in an amount of from about 0.05 to about 0.5 kilograms per kilogram of acid sulfonate product.
The reined petroleum sulfonates produced by the process of this'invention are useful in the formulation of micellar dispersions comprised of hydrocarbon, water and petroleum sulfonate, which are utilized in oil recovery processes. Examples of such micellar dispersions include micellar flooding of subterranean reservoirs with systems of the type taught by H. J. Hill, J. Reisberg, and G. L. Stege-meier, J. Pet T_ch., 186 tFeb~ 1973), wherein relativelydilute aqueous "solutions n o~ sur~actant and/or cosurfactant are injected, the process of R. L. Reed, et al., U.S.
Patent 3,885,628 wherein a multiphase system is injected;
and U.S. Patent 3,082,822 issued to L. W. Holm et al., wherein substantially small slugs of anhydrous-soluble oils 11~4177 are alternately injected with small slugs of ~ater or other aqueous media. The neutralized sulfonates used in such micellar dispersions should have an a~erage equivalent weight of from about 350 to about 525, preferably from about 05 395 to abou-t 440 and more preferably from about ~00 to about 4~0. Ge~erally, the water soluble petroleum su~fonates have a lower equivalent wei~ht, whereas, the more o-il soluble petroleum sulfonates have higher equivalent wei~hts. These petroleum sulfonates are also useful in other t~pes of sur~actant floods used in oil reco~ery processes.
Figure 1 exemplifies the process of the present inven-tion. Cruae oil and sulfur trioxide vapor enter a sulfo-nation reactor 3 through lines 1 and 2, respectively.
The resultant product mixture containing sulfonic acids and unreacted oils is conducted by conduit 4 to a liquid/~as separator 5. Sulfur dioxide, light hydrocarbons and diluent solvent, ~hen it is usea, are separated and xemoved from the sulfonated product mixture via conduit 6. If desired, these gaseous proaucts, e.g., sulfur dioxide and light hydrocar-bons, can be recycled to the sulfonation reactor for use asa reaction solvent. If a diluent solvent is used which re-mains in the liquid phase, it can be removed by an~ appro~
priate means at any time later in the process. While the ,~ sulfonated product mixture is being conducted throu~h f ~
conduit 7 to settler 8, water is added to the mixtur~ The water and sulfonated product mixture are then allowed to separate in settler 8 until the acidic sulfonate pxoduct mixture contains from 5 to about 15 percent b~ vo~ume o~
free unreacted hydrocarbon. The free unreacted h~drocarbons are then removed by conduit 10 and ultimately recombined with the raffinate obtained by the separation of the neu-tralized petroleum sulfonate. The sulfonic acids from settler 8 are conaucted by conduit 11 to neutralizer 12, wherein the sulfonic acids are neutralized by the addition of a base supplied t~ough conduit 13. Water can be added, .
~g if desired, to the neutrali~er, thxou~h a separate con~it 14 or via conduit 13 as a carrier for the base. The sul-fonation product is then conducted through line 15 to an-other settler 16. If needed, kerosene can be added to the 05 sulonated product via conduit 17 prior to i~s introduction in either settler 8 or settler 16~ The addition of this kerosene is as an adjunct to extract waxes from the petro-leum sulfonate. The petroleum sul~onate is then allowed t:o settle until a complete phase separation has occured between the unreacted oil and the petroleum sulfonate. Thereafter, the xaffinate is separated from the sulfonate an~ remo~ed from the settler via conduit 18. The crude oil s~lfonate is removed via conduit 19 and thereafter incorporated into a micellar dispersion for use in an oil xecovery process.

Sam~les of different crude oils were prepaxed by sulfonating each crude oil at a rate of a~out 450 kilograms per hour with 45 kilograms per hour of sulfur trioxide at a temperature of about 80 CO The vapor stream was then separated from the liquid stream containing sul~onic acids, sulfuric acid, sulfurous acid and unreacted oils~ Then, the liquia stream was mixed with about 400 kilo~rams of fresh water per hour and enough ammonia to obtain a pH of about 6.
In some cases approximately 220 kilo~rams of kerosene per hour were also added at this point to reduce the ~inal wax content of the crude oil sulfonate product. This neutral-ized liquid stream was allowed to settle ~or about 4 hours in a settling tank having a 3800 liter capacity in order to effect a phase separation between the raffinate tunreacted oil) and the crude oil sulfonate (COS). These two phases were separated and the crude oil sulfonate contained no detectable free oil as it left the settler. Thereafter, the COS was allowed to settle for the time indicated in Table 1. -The amount of residual raffinate which separated from the COS during this time period is also ~iven in Table 1. The 1144~77 raffinate continued to come out of solution ~or ~everal days and often for several weeks.

TABL~ 1 Residual 05 - Time Period Xaf~inate Sam~le Cr~de:~il Feedstock ~Iours~ - (vol. ~) 1 Bailey/North Craw- 0 0 ford County, 3 0.5 Indiana (Kerosene 5 1. n added during 7 1.3 neutralization) 8 ~7 1.9 Sl 2.X
121 ~-~
244 ~.6 364 2.7

2 Baile~/North Craw- 0 0 ford County, 3 . 0.5 Indiana ~Kerosene S 1.1 added during 7 1.~
neutralization) 8 1.4 27 l.g 97 2.
~20 ~-~
340 ~.6

3 Muddy Creek 42 . ~. n

4 Indiana 50 0.8 Bailey 111 2.8 6 North Crawford County77 ~.3 30 ~ Bailey/Muddy Creek 216 ~-~
8 Bridgeport 16~ 1.0 .

~ ... .
A crude oil sulf~ate was prepared by sulfonating 450 kilograms per hour of Craword County, Xllinois cxude oil with 45 kilograms of sul~ur trioxide at a temperature of 80 C. Samples of the thus obtained acidic crude oil sulfo-nate (ACOS) were allowed to settle and separate into a .

1~44~77 raffinat~ and acidic cxude'oi.l sulfonate.phases. The two phases were then subjected to an incomplete separation and the amount of raffinate which the separated acidic crude oil sulfonate containea is given in Fi~ure 2. With some o 05 the samples, additional raffinate was remixe~ into the already separated acidic crude oil sulfona~e. Thereafter, all of the samples were neutralized with suf.ic:ient ammonia to obtain a crude oil sulfonate~rafinate mixture having a pH about 6-6.5. Each of the samples was allowed to settle and the time required for complete separation ~etween the ~eutxalized cxude oil sulfonate and the xaffinate is given in Figure 2.

Four hundred fifty kilograms per hour of a Crawford County, Illinois crude oil was reacted with 45 ~ilo.grams per hour of sulfur trioxide at a temperature of 82 C. A~ter separating off the vapor stream, composed mostly of light hydrocarbons and sulfur dioxide, the xemaining stream, i.e.
the sulfonic acid p~ase, co~posed most~y o sulfonic acids, ~- sulfuric acid, sulfurous acid and nnreacted hydrocarbQns, was processed in the following ways:
Sample l:
The sulfonic acid phase was mixed with ~50 kilograms per hour of resh water and enough ammonia to ~i~e a pH of about 6, then allowed to separate over four hours'at 70 C
in a 3800 liter settler. Foux samples of ~he crude oil sulfonate stxeam fxom the settler were held or varying time periods at 70 C in volumetric flasks to determine how much residual rafinate would separate into a top phase. A
residual rafinate layer of 1.1 percent by volume was ob-tained from a sample held for twenty hours; 1.6 and 1.7 percent by volume residual raffinates were obtained from two samples held for three'days and a sample hel~ for 28 days showed a raffinate layer of 2.0 percent by vol~une.
T~e average'time'required for complete settling of the neutralized stream into a raffinate phase and the pet'roleum ., ~ .

11441~7 ~12-sulfonate phase was 9S minutes. The settling time was obtained by taking about foot high samples of the neutral-ized stream in 1000 milliliter gradua~ed cylinders, main taining the temperature o the samples at 70 C and then 05 measuring the time required to ob~ain the phase separation.
Sample 2:
.

The sulfonic acid phase was treated wi~h ~50 kilo~rams per hour of fresh water, then ~is mixture was settled ~t 60 C in a 3400 liter settler with a resiclence ~ime of about 3.5 hours. The two streams from the settler, the ra~finate and acid crude oil sulfonate, were then recombined and neutralized with ammonia to a pH of about 6. '~his mix, which containea about 38 percent ~y volume raffinate, was then put through a second settler o 380Q :Liter capacity at 70 C and a residence time of about 4 hours. ~fter sepa-ration of the neutralized COS and raffinate, ~amples o the crude oil sulfonate were held at 70 C in ~olumetri~ flasks for several hours, at which time a~out 0O~ volume percent residual raffinate separated to the top o~ the ~rude oil sulfonate. More raffinate would have separat:ed c>ut had this sample been held longer at 70 C.
Sample 3:
Fresh water, at a rate of 450 kilo~rams per hour, was added to the sul~onic acid phase, then this mixture was allowed to separate in a 3400 liter settler with a xesi~ence time of about 3.5 hours at a temperature o~ ~0 ~. A
stream of clear raffinate was removed from the top of the settler. The acid crude oil sulfonate stream from the bottom o the settler was not clear and it ~ontained about 40% of the total raffinate. This stream was neutraliæed with ammonia to a pH of about 6, and then put through a second settler of 3800 liter capacity at 10 ~ and a resi-dence time of about 5 hours. Samples of this neutrali2ed stream entering the second settler were ~atch settled at 70 C and showed 10.3 and 16.4 volume percent raffinate.
Samples of the raffinate free crude oil sulfonate stream ~ere held at 70 C in volumetric flasks for several hours.
No residual raffinate was ohserved. Obser~ation for several more hours stlll showed no residual raffinate.
Sam~le 4:
S The run conditions were the same as those of Sample 3, except that the first settler was at abou~ 60 C and the acid crude oil sulfonate from the first settler con~ained about 10 percent of the total ~af~inate. Samples o~ the neutrali~ed stream entering the second settler were batch settled at 70 C and showed 3.5, 8.8, and 3.3 volume percent ra~finate. Samples o~ the raffinate free crude oil su~fo-nate fxom the second settler were held at temperature ~n volumetric flasks for several hours. No residual raffinate separated to the top. Observation for several more houxs still showed no residual raffinate.

EX~MPLE 4 Four hundred fifty kilograms per hour of a Crawford County, Illinois crude oil was reacted with 45 kilo~rams per houx of sulfur trioxide at 80 C. After separating off the vapor stream, composed primarily of light hydrocarbons and sul~ur dioxide, the remaining stream, i.e. the sulfonic acid phase, composed mostly o~ sul~onic acids, sulfuric acid, sulfurous acia and unreacted hydrocarbons was mixed with ~50 kilograms per hour of fresh water and put into a 3400 liter settler for a residence time of about 3.5 hours. This acid separation and a second separation at nearly neutral con-ditions were varied, as described in each of the following . ~ samples.' Sample 1: -In this sample, two separate acid separations were conducted at a temperature of 50 C (Sample lA) and 70 C
(Sample lB~. Both resulted in a clear rafffina-te stream and a nearly clear acid crude~oil sulfonate ~ream. Both acid crude oil sulfonate streams wexe n~ ralized with ammonia to ... . .

~144177 .

a pH of about ~ and then allowed to reside for a~out 6 hours in a second settler at a temperature of 70 C. ~ sample o~
about one foot height of each of the neutralized crude oil sulfonate was taken in a 1000 millilite~ graduated c~linder S and held at 70 C. Sample lA too~ 45 minutes t~ completely separate and 2.4 percent by volume of raffinate was removed;
Sample lB took 50 minutes to completely separa~e and 2.9 percent by volume of raffinate was removed.
Samples 2-4:
Additional samples were subjected to the same two step separation process of Sample 1 with the exception that the acid separation was not complete. The amount o~ raffinate left in the acid crude oil sulfonate is in~icatea in Table 2 as are the results of the neutraliæed ~eparation.

Settlin~ Rafinate time of ~emo~ed Temperature Raffinate Neutrali~ea ~n ~nd of Acid left in COS (min- Separation 20 SeparationACOS (vol.~ tes~ (vol.%) .._ . . . . .
50 ~ 7-8 24 10.3 70 C 5.5-6.5 ~2 ~.
70 C 14 40 16.4 Sample 5:
In this sample the acid separation was conducted at a temperature of 60 C. The separated ra~finate was recombined with all of the acid cxude oil sul~onate stream ana then neutralized with an~onia to a pH of about 6. This neutral-ized stream was flowed into a second settler where it settle~ for 4 hours at a temperature of 70 C. A sample of one-~oot height taken of this neutrali~ed inlet stream to the second settler took 135 minutes to completel~ separate and 38.1 percent by volume of raffinate was removed.

Claims (26)

Claims

1. In a process for the preparation of petroleum sulfonates comprising contacting sulfur trioxide with a hydrocarbon selected from the group consisting of whole crude oil, topped crude oil and mixtures thereof in a reac-tion zone, at a temperature of from about 27° C to about 121° C, at a pressure of from about 0.01 to about 150 atmo-spheres and for a reaction time of from about 0.001 to about 3600 seconds wherein from about 5 to about 30 kilograms of sulfur trioxide are contacted with each 100 kilograms of hydrocarbon, the improvement comprising;
adding from about 0.1 to about 3.0 kilograms of water per kilogram of the sulfonated product mixture;
partially removing free unreacted hydrocarbons to obtain an aqueous/sulfonated product mixture containing from about 5 to about 15 percent by volume of the free unreacted hydrocarbons;
neutralizing with a base the sulfonated product containing from about 5 to about 15 percent of the free unreacted hydrocarbons; and thereafter removing all of the free unreacted hydrocarbons from the neutralized product mixture

2. In a process for the preparation of petroleum sulfonates comprising contacting sulfur trioxide with a hydrocarbon selected from the group consisting of whole crude oil, topped crude oil, and mixtures thereof in a reaction zone, at a temperature of from about 27° C to about 121° C, at a pressure of from about 0.01 to about 150 atmo-spheres and for a reaction time of from about 0.001 to about 3600 seconds wherein from about 5 to about 30 kilograms of sulfur trioxide are contacted with each 100 kilograms of hydrocarbon, the improvement comprising;
adding from about 0.1 to about 3 kilograms of water per kilogram of the sulfonated product mixture;

removing free unreacted hydrocarbons from the aqueous/sulfonated product mixture;
adding a portion of the unreacted hydrocarbons back to the product mixture so that the product mixture contains from about 5 to about 15 percent by volume of free unreacted hydrocarbons;
neutralizing with a base the sulfonated product mixture containing a portion of the free unreacted hydro-carbons: and removing the free unreacted hydrocarbons from the neutralized product mixture.

3. The process of Claim 1 or Claim 2 wherein from about 0.05 to about 0.5 kilograms of kerosene are added per kilogram of product mixture after the first removal of free unreacted hydrocarbons and prior to the neutralization of the product mixture.

4. The process of Claim 1 wherein the contact between the hydrocarbon and the sulfur trioxide occurs in the presence of from about 0 to about 20 kilograms of a diluent, substantially inert to reaction with the sulfur trioxide, per kilogram of the sulfur trioxide present in the reaction zone.

5. The process of Claim 4 wherein the diluent is selected from the group consisting of ethylene dichloride, trichloroethane, nitrobenzene, nitropropane, sulfur dioxide, refined light paraffins, crude oil light ends, air, nitrogen, natural gas and mixtures thereof.

6. The process of Claim 1 or Claim 2 wherein said hydrocarbon has an average molecular weight in the range of from about 200 to about 1,000 and contains from about 10 to about 95 percent by weight aromatics.

7. The process of Claim 1 or Claim 2 wherein said hydrocarbon consists essentially of whole crude oil.

8. The process of Claim 1 or wherein said hydrocarbon consists essentially of topped crude oil.

9. The process of Claim 8 wherein said contact between the sulfur trioxide and the hydrocarbon occurs in the pres-ence of a diluent selected from the group consisting of ethylene dichloride, trichloroethane, nitrobenzene, nitro-propane, sulfur dioxide, refined light paraffins, crude oil light ends, air, nitrogen, hydrocarbon gases and mixtures.
thereof at a temperature of from about 27° to about 121° C
and a pressure of from about 0.01 to about 150 atmospheres and wherein there are present for each kilogram of sulfur trioxide from about 1 to about 20 kilograms of the diluent.

10. In a process for the preparation of sulfonates useful in the preparation of micellar dispersions for sup-plemented recovery of oil, said sulfonates having an average equivalent weight of from about 350 to about 525, by con-tacting sulfur trioxide with hydrocarbon selected from the group consisting of whole crude oil, topped crude oil or mixtures thereof, at a temperature of from about 27 to about 121° C, at a pressure of from about 0.01 to about 150 at-mospheres and for a reaction time of from about 0.001 to about 3600 seconds wherein from about 5 to about 30 kilo-grams of sulfur trioxide are contacted with each 100 kilo-grams of hydrocarbon, the improvement comprising:
partially extracting the sulfonated portion of the product mixture with from about 0.3 to about 1.5 kilograms of water per kilogram of product mixture to obtain an aqueous/sulfonated product mixture containing from about 5 to about 15 percent by volume of free unreacted hydrocarbon neutralizing with a monovalent base the sulfonated product containing from about 5 to about 15 percent free unreacted hydrocarbon;
permitting the sulfonate product and free unre-acted hydrocarbon to separate; and removing the free unreacted hydrocarbon from the sulfonated product.

11. In a process for the preparation of sulfonates useful in the preparation of micellar dispersions for supplemented recovery of oil, said sulfonates having an average equivalent weight of from about 350 to about 525, by contacting sulfur trioxide with hydrocarbon selected from the group consisting of whole crude oil, topped crude oil or mixtures thereof, at a temperature of from about 27 to about 121°C, at a pressure of from about 0.01 to about 150 atmospheres and for a reaction time of from about 0.001 to about 3600 seconds wherein from about 5 to about 30 kilograms of sulfur trioxide are contacted with each 100 kilograms of hydrocarbon, the improvement comprising:
partially extracting the sulfonated portion of the product mixture with water to obtain an aqueous/sulfonated product mixture containing from about 5 to about 15 percent b. volume of free unreacted hydrocarbon;
neutralizing with a monovalent base the sulfonated product containing from about 5 to about 15 percent free unreacted hydrocarbon;
permitting the sulfonate product and free unreacted hydrocarbon to separate; and removing the free unreacted hydrocarbon from the sulfonated product.

12. In a process for the preparation of petroleum sulfonates comprising contacting sulfur trioxide with a hydrocarbon selected from the group consisting of crude oils, topped crude oils, gas oils and mixtures thereof in a reaction zone at a temperature of from about 27°C to about 121°C and a pressure of from about 0.01 to about 150 atmospheres for a reaction time of from about 0.001 to about 3600 seconds wherein from about 5 to about 30 kilograms of sulfur trioxide are contacted with each 100 kilograms of hydrocarbon, the improvement comprising:
(a) allowing the sulfonate product mixture to separate into a free unreacted hydrocarbon phase and an acid sulfonated product phase;
(b) separating the sulfonate product mixture into a phase containing a portion of the free unreacted hydrocarbon and an acid sulfonated product phase containing the remainder of the free unreacted hydrocarbon such that the remainder of free unreacted hydrocarbon causes a faster separation between unreacted hydrocarbon and neutralized sulfonate product than is possible if a complete separation were effected between the free unreacted hydrocarbon and the sulfonated product mixture to be neutralized;
(c) neutralizing with a base the acid sulfonated product mixture containing the remainder of the free unreacted hydrocarbon of step (b); and (d) thereafter removing all of the free unreacted hydrocarbon from the neutralized sulfonated product mixture at a rate of from about 0.3 to about 0.6 hours per foot of emulsion.

13. A process of enhancing the separation of unreacted hydrocarbons from the sulfonated product mixture obtained by contacting about 5 to about 30 kilograms sulfur trioxide per 100 kilograms of a hydrocarbon selected from the group consisting of crude oils, top crude oils, gas oils and mixtures thereof in a reaction zone at a temperature of from about 27°C to about 121°C and a pressure from about 0.01 to about 150 atmospheres for a reaction time of from about 0.001 to about 3600 seconds to form a sulfonated product mixture from which a raffinate comprising free unreacted hydrocarbons separates, said method comprising the steps of:
(a) removing a portion of said raffinate thereby leaving the remainder of said raffinate with said sulfonated product mixture;
(b) neutralizing with a base said sulfonated product mixture containing said remainder of said raffinate to form a neutralized sulfonated product mixture and a second raffinate; and (c) thereafter removing said second raffinate from the neutralized sulfonated product mixture, the remainder of said raffinate in step (a) being in an amount sufficient to enhance the separation rate of said second raffinate and said neutralized sulfonated product mixture thereby enabling the removing of step (c) to take place at a rate faster than that which would take place if substantially all of said raffinate has been removed prior to step (b).

14. The process of Claim 13 wherein step (a) comprises removing substantially all of said raffinate and thereafter adding a portion of the raffinate as said remainder to said sulfonated product mixture prior to the neutralizing of step (b).

15. The process of Claim 13 further comprising adding an extraction solvent to the sulfonated product mixture prior to step (a).

16. The process of Claim 13 or Claim 15 wherein the sulfonate product mixture prior to its neutralization contains an amount of said remainder of said raffinate which will cause a separation between the neutralized sulfonate product and free unreacted hydrocarbon to occur at a rate of from about 0.3 to about 0.6 hours per foot of emulsion.

17. The process of Claim 13 or Claim 15 wherein the sulfonate product mixture prior to its neutralization contains from about 7 to about 12 percent by volume of said remainder of said raffinate.

18. The process of Claim 15 wherein the extraction solvent is used in an amount of from about 0.1 to about 3 kilograms per kilogram of sulfonated product mixture.

19. The process of Claim 18 wherein the extraction solvent is selected from the group consisting of water and a low molecular weight aqueous alcohol.

20. The process of Claim 19 wherein the hydrocarbon to be sulfonated is selected from the group consisting of crude oils and topped crude oils and the extraction solvent is water.

21. The process of Claim 19 wherein the hydrocarbon to be sulfonated is a gas oil and the extraction solvent is a low molecular weight aqueous alcohol.

22. In a process for the preparation of petroleum sulfonates useful in the preparation of micellar dispersions for supplemental recovery of oil, said sulfonates having an average equivalent weight of from about 350 to about 500 by contacting sulfur trioxide with hydrocarbon selected from the group consisting of crude oils, topped crude oils, gas oils and mixtures thereof at a temperature of from about 38°C
to about 93°C and a pressure of from about 0.15 to about 75 atmospheres for a reaction time of from about 0.01 to about 360 seconds wherein from about 7 to about 20 kilograms of sulfur trioxide are contacted with each 100 kilograms of hydrocarbon, the improvement comprising:
(a) partially extracting free unreacted hydrocarbon from the sulfonated product mixture with from about 0.1 to about 3.0 kilograms of an extraction solvent per kilogram of sulfonated product mixture to obtain sulfonated product mixture containing from about 7 to about 12 percent by volume of the free unreacted hydrocarbon;
(b) neutralizing with a monovalent base the sulfonated product mixture containing from about 7 to about 12 percent free unreacted hydrocarbon;
(c) permitting the sulfonate product mixture and free unreacted hydrocarbon to separate; and (d) removing all of the free unreacted hydrocarbon from the neutralized sulfonated product.

23. The process of Claim 22 wherein the extraction solvent is used in an amount of from about 0.3 to about 1.5 kilograms per kilogram of the sulfonated product mixture.

24. The process of Claim 22 wherein the extraction solvent is selected from the group consisting of water or a low molecular weight aqueous alcohol solution.

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25. The process of Claim 24 wherein the hydrocarbon sulfonate is selected from the group consisting of crude oils and topped crude oils and the extraction solvent is water.

26. The process of Claim 24 wherein the hydrocarbon feedstock sulfonate is a gas oil and the extraction solvent is a low molecular weight aqueous alcohol selected from the group consisting of aqueous ethanol and aqueous propanol.
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