US1988835A - Process for breaking petroleum emulsions - Google Patents

Description

Patented Jan. 22, 1935 v r i v PROCESS FOR BREAKING PETROLEUM EMULSIONS No Drawing. Application March 15, 1934,

Serial No. 715,772 I 9 Claims. (01. 196-4) I This invention relates to the treatment of emul-' relationship to each. other or to the parent fatty sions of. mineral oil and water, such as petroleum acid or' fatty acid compound from which they emulsions, for the purpose of separating the oil were derived. Thus, while modified fatty acids from the water. y do include the salts of modified fatty acids, they Petroleum emulsions are of the w'ater-in-oil. do not include salts of unmodified fatty acids, type, and comprise fine droplets of naturally-ocsuch as soaps, becausea salt of a fatty acid is not curring waters or brines, dispersed in a more or an addition product, Likewise, it is not a substiless permanent state throughout the oil which tution product, because substitution products" constitutes the continuous phase of the emulsion. in the sense that such term is used in organic m They are obtained from producing wells. and from chemistry, is applied not to salts, but to undisso- 10 the bottom of oil storage tanks, and are commonciable or indifferent compounds. Furthermore, ly referred to as cut oil, "roily oil, "emulsified whereas the acid hydrogen involved in salt foroil, and bottom settlings. mation can be replaced only by metals or metal- The object of our invention is to provide a like groups, that is, elements or radicals which novel and. inexpensive process for. separating are electro-positive, substitution may replace the 15 emulsions of the character referred to into their hydrogen of organic compounds by a variety of component parts of oil and water or brine. elements and groups which may be electro-nega- Briefly described, our process consists in sub-. tive. Modified fatty acids retainmost of the jecting a petroleum emulsion of the water-in-oil fundamental characteristics of fatty acids them- 24 type, to the'action of a treating agentror demulselves, and are generally characterized by the 29 sifying agent of the kind hereinafter described, outstanding identifying property of a fatty acid thereby causing the emulsion to break down and or fat, 1. e., the ability to stain paper so .as to separate into-its component parts of oil and wa-- leave a translucent spot, at temperatures above ter or brine, when the emulsion is permitted to rethe melting point, and to undergo saponification.

as main in a quiescent state or subjected to other The treating agent or demulsifying agent conequivalent separatory procedure. templated by our process includes esters of a The treating agent or demulsifying agent used specific kind derived from either fatty acids or in our process consists of an ester of a fatty acid modified fatty acids. In order to keep the disor modified fatty acid, in which the carboxylic hy tinction clear between a. fatty acid and a modi- 80 drogen has been replaced by asulfonated aliphatic fied fatty acid and yet use a term which will be 30 residue; Fatty acids are well known demulsifying inclusive of both classes, the expression fatty agents for water-in-oil emulsions, and are disacid body will be herein used to indicate both closed in U. S. Patent No. 1,223,659, dated April classes of materials. A fatty acid may be indi 24, 1917, to William S. Bax-nickel. Likewise, mod-- cated by the formula R.COOH, in which R is a ified, fatty acids or their salts or esters are well fatty acid radical such as an oleic acid radical,

mown demulsifying agents for water-in-oil emulstearic acid radical, palmitic acid radical, ricinosions, and are disclosed in U. S. Patent No. 1,467,- leic acid radical,-and COOH indicates the con- 831, dated September 11, 1923, to William S. ventional carboxyl radical. If the-fatty acid is Bar-nickel. From the standpoint of said U. S. of the unsaturated type, such as oleic acid,

40 Patent No. 1,467,831, the acidic hydrogen of the ricinoleic acid, etc., and one produces an 'addi- 40 modified fatty acid carboxyl may be replaced by tion product by means of a chemical reagent,

a metal or organic radical, such as a CsHs radical. then the modified fatty acid thus obtained is The expression modified fatty acids is well indicated by theformula RHCOOH, in which understood by those skilled in the art of resolv- XX represents atoms or radicals joined in addiumrso STATES-PATENT OFFI'C at ing petroleum emulsions of the water-in-oil type, tion, such as OH, H804, H503, Cl, Br, CsH4HSO3,

and has been used frequently in the patent litetc. XX may represent the same atoms as in erature to designate a certain well known class of .the case of oleic acid dichlorid XX y materials. For... sake of simplicity and brevity represent an atom and a radical, as in the case only, the following discussion will consider the of oleic acid hydrogen hydrogen sulfate. Inevent carbonfatty acid as yp al of acid, that the fatty acid contained more than one 50 salt and s i y described, O fi d fatty ethylene linkage, such as linoleic acid, then one acids are modifications offatty acids obtained by might obtain a modified fatty acid of the type chemical reaction on a fatty acid or its equiva- RXXXXCOOH, but this is simply considered lent, so-as to resultin an addition product or subas a variety of the R.XX.COOH species.

stitutl'on product, and they bear a simple genetic Just as the fatty acid ef the type R.CQOI-I stirring for ten hours, when may yield addition products, likewise, it may yield substitution products, and such a modified fatty acid may be designated by the formula R'D.COOH, in which R'is a fatty acid radical residue, D is the substituent atom or radical, such as HSOi, CeH4HSO3, a phthalic acid residue, an

oxalic acid residue, an acetic acid residue, a

phosphoric acid residue, chlorine, etc., or a residue of the type R".CO0, in which R. indicates another fatty acid radical residue which may be different, or it maybe the same as R, as in the case of poly acids, such as diricinoleic, triricinoleic, etc., and CO0 is a carboxyl residue.

Fatty acids, such as ricinoleic acid, may yield a modified fatty acid which is both an addition and substitution product. For instance, ricinoleic acid may yield a modified fatty acid which is both an addition and a substitution product and may be indicated by the formula RDXXCOOH, in which the various symbols have the same significance as previously. The formula R.COOH includes fatty acids, such as olelc acid, ricinoleic, stearic acid, etc. The formulas R.XX.COOH, R'D.COOH,'and R'D.XX.COOH include the conventional modified fatty acids. Fatty acid bodies are selected from the class comprising:

R.COOH R.XX.COOH RD.COOH R'D.XX.COOH,

in which the symbols have their previous significance. The above formulas indicate the simple genetic relationship existing among the members of the class.

The treating agent or demulsifying agent employed in our present process is a sulfo aliphatic ester of a fatty acid body, that is the ester of either a fatty acid or a modified fatty acid, in which a sulfo aromatic residue has replaced the carboxylic hydrogen of the fatty acid or modified fatty acid. The production of such sulfo aliphatic esters may be accomplished in a variety of manners. A number of methods for producing such sulfo aliphatic esters are disclosed in U. S. Patent No. 1,881,172, dated October 4, 1982, to Karl Daimler and Karl Platz. Briefly stated, one method contemplates reacting the reaction product of ethyl alcohol and sulfuric-anhydride with a fatty acid at approximately 45 C. and

' the mass is introduced into ice water and the whole is then washed with a solution of sodium chloride. 0n

neutralization, a white paste is obtained which dissolves when diluted with water.

The methods disclosed in said U. S. Patent No. 1,881,172 are applied to fatty acids, but it is obvious that they are also applicable to modified fatty acids of the type previously indicated.

If a fatty acid is indicated by the formula RCOOH, then the sulfo aliphatic ester may be indicated by the formula R.COO(T.SOa.Z), in

which R has the same meaning as previously indicated, COOH is the carboxyl residue, T is the aliphatic residue, S03 is the conventional sulfonic acid residue, and Z represents the hydrogen of the sulfonic acid or its equivalent, such as a metal atom, for example, a sodium or potassium, or else an ammonium radical, basic amine radical, calcium, magnesium, etc., or Z may be an organic radical, such as a 021-15 radical. Corresponding to a sulfo aliphatic ester of the fatty acids, one may obtain the sulfo aliphatic esters of the modified fatty acids, and they may be designated by the following type formulas:

RDXX.C00(T.SO3.Z), in which th symbols have the same significance as previously. It is to be notedthat (T.SO3Z) replaces the carboxylic' hydrogen in both modified and unmodified fatty acids.

As pointed out in U. S. Patent No. 1,881,172, previously referred to, these reagents have a great wetting power, and thus presumably are colloidal in character, and they are surface active. -A great many substances which give colloidal solutions and are hydrophile or lipophile are excellent demulsifying agents for water-inoil emulsions. However, the list of reagents which are capable of acting as wetting agents, frothing agents, emulsifying agents, etc., has increased to such a marked degree that it includes large classes of materials which are not of any significant value as demulsifying agents.

The treating agent that we prefer to use in practising our process is preferably prepared in the following manner: The dry potassium salt of ricinoleicacid is prepared by saponification of castor oil in the conventional manner. To approximately 436 parts by weight of this salt are added approximately 148 parts by weight of -phthalic anhydride and the mixture heated at of the reaction product is substantially nil. The

product thus obtained consists principally of a phthalic acid residue, united through one carboxyl with a glycerol residue, and through the other carboxyl with sodium ricinoleate by combination through the alcoholiform hydroxyl of the ricinoleate. This product is agitated vigorously with dilute hydrochloric acid so as to de; compose the salt, with the liberation of the free glyceryl phthalylricinoleic acid. Care must be taken so as not to decompose the' ester. The ester is then freed of excess water and dried over anhydrous sodium sulfate' TOgthiS ester is then added approximately 200 parts byweight of ethionic acid (obtained from ethyl alcohol and sulfuric anhydride), at a temperature of approximately 45 C., and the mixture stirred for ten hours. This mixture is then introduced into approximately 300 parts by weight of ice water while stirring and the whole mass is subsequently washed with a solution of sodium chloride. On neutralization a white paste is obtained which disolves when diluted with water. The reaction probably takes place according to the equation:

Another treating agent or demulsifying agent that we may use in practising our process, is prepared as follows: Approximately 436 parts by weight of dry potassium ricinoleate is heated at approximately 140 C., with approximately 148 parts of phthalic anhydride until the reaction'is "ricinoleic acid group one tothe phthalic acid group. Of course,. there will be present some of each of the two monoesulfonates posadded. n standing, the ricinoleic ester of the hydroxy ethane sulfonic acid is deposited on the bottom. The top layer is withdrawnand the lower layer neutralized as such or washed again with a 20% solution of sodium chloride and then neutralized.

Still other treating agents or demulsifying agents capable of use in our process, can be produced by reacting allyl alcohol with potassium acid sulflte and forming the hydroxy propane sulfonic acid salt, and subsequently reacting 120 parts by weight of this salt with 155 parts by weight of castor oil and passing a current of dry hydrochloric acid gas through the mixture. After 24 hours the reaction is complete. This product is soluble in water to a clear solution. The reaction product is purified and finished as in the preceding example.

It is understood wherever the replaceable hydrogen is present in the reagent, for instance, the replaceable hydrogen of the carboxyl radical of the phthalic acid residue previously mentioned, that said acid hydrogen maybe replaced by any of the customary radicals, such as sodium, potassium, ammonium, basic amine radicals, ethyl radicals, methyl radicals, etc. Reagents thus produced will show the widest variety in their solubility. Some may be water-soluble, some may be. oil-soluble, some may be soluble in both water .andoil, and some may be substantially insoluble in either oil or water. It appears paradoxical to speak of breaking an oil field emulsion bymeans of areagent which is substantially insoluble in' either oil or water. On the other hand, it must be remembered that oil field emulsions are frequently broken by the addition of onepart of a chemical reagent to 20,000 parts or 30,000 parts of emulsion. Thus, even though a reagent is substantially insoluble in oil and in water, yet it may be sufilciently soluble so that it is entirely dissolved in the minute amount in which it may be used.

The specific form, state, or condition of thetreating agent at the time it is used or applied solvent, such as ethyl. alcohol, methyl alcohol,

isopropyl alcohol, butyl alcohol, kerosene, or any other hydrocarbon solvent, benzol, xylene, solvent naphtha, carbon tetrachloride, pine ofl, etc.

The treating agent can be employed either alone or in admixture or combination with other wellknown treating agents for breaking. petroleum emulsions of the water-in-oil type, such as water softeners, modified fatty acids, petroleum sulfonic acids, or their salts, etc.

In practising our. process, a treating agent or demulsifying agent of the kind above described -isbrought in contactwith the emulsion to be treated, etc.

Having thus described our invention, what we desire to secure by Letters Patent is: i

1. A process for breaking petroleumemulsions of the water-in-oil type, which consists inIsubje'cting the emulsion to the action of a demulsifying agent containing a sulfa-aliphatic ester of a fatty acid of the type R".COO (T.SO:.Z) in which R" is a fatty acid radical, CO0 is a carboxyl residue, T is the aliphatic residue, S03 is the conventional sulfonic acid residue, Z represents the acidic hydrogen atom of the sulfonic acid or its equivalent, and (T.SO:|.Z) replaces the carboxylic hydrogen. 7

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo-aliphatic ester of a modified fatty acid of the type in which R' is a modified fatt acid radical,

in which R'D is a modified fatty acid residue oi the substituted type, D is a substituent atom or radical attached to R, CO0 is a carboxyl residue, T is the aliphatic residue, S03 is the conventional sulfonic acid residue, Z represents the acidic hydrogen atom of the sulfon'ic' acid or its equivalent, and (T.SO3.Z) replaces the carboxylic hydrogen.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo-aliphatic ester of a modified fatty acid of the type" R'D.COO (T5031) in which R'D is a modified fatty acid residue of the substituted type, -D is a substitu'ent dibasic carboxy acid residue attached to R, CO0 is a carboxyl residue, T is the aliphatic residue, S0; is the conventional sulionic acid residue, Z represents the acidic hydrogen atom of the suli'onic acid or its equivalent, and (T.S0a.Z) replaces the carboxylic hydrogen.

5. A process for breaking petroleum emulsions of the water-in-oil type. which consists in subjecting the emulsion to the action of ademulsifying agent containing a sulfa-aliphatic ester of a modified fatty acid of the type in which R'D is a modified fatty acid residue of the substituted type, D is a substituent phthalic acid residue attached to R, CO0 is a carboxyl residue, T is the aliphatic residue, S0: is the conventional sulfonic acid residue, Z represents the acidic hydrogen atom of the sulfonic acid or its eq'uivaient, and (T.SOa.Z) replaces the carboxyiic hydrogen.

6. A process for breaking petroleum emulsions of the water-in-oil type. which consists in subiecting the emulsion to the action of a demulsifying agent containing a sulfa-aliphatic ester of a modified fatty acid of the type R'ncoo (T.SO:.Z) in which R'D is a modified fatty acid residue of the substituted type, D is a substituent phthalic.

R'D.CO0(T.SOa.Z) in which ED is a modified fatty acid radical of the substituted type, D is a substituent phthalic acid residue attached to R, CO0 is a carboxyl residue, 'I' is an ethane derivative, S03 is the conventional sulfonic acid residue, Z represents a metal atom, and (T.SO3.Z) replaces the carboxylic hydrogen.

v 8. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containingthe hydroxy ethane sulfonic ester of phthalyl ricinoleic acid in the form of a water-soluble salt.

9. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing the hydroxy ethane sulionic ester of phthalyl ricinoleic acid in the form of a water-soluble ammonium salt.

MELVIN DE aaoo'ra. ARTHUR F. wmm.