MXPA98006858A - Ammonium hydroxides as mercapt depurers - Google Patents

Abstract

A method for the depuration of mercaptans in a hydrocarbon fluid is disclosed. According to the method, an effective mercaptan cleansing amount of an aqueous cleansing composition is added to the fluid. The composition comprises a quaternary ammonium hydroxide of the formula R1R2R3R4NOH, R1 and R2 are independently alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven about eighteen carbon atoms , R3 is an alkyl group of two to about eighteen carbon atoms, an aryl group of two to about eighteen carbon atoms or an alkylaryl group of four to about eighteen carbon atoms, R2 and R3 can be attached to form a heterocyclic ring including N and optionally an oxygen atom, R4 is - (CH2CH2O) nH, wherein n is an integer from one to about eighteen, or -CHR5CHR6Y, wherein R5 and R6 are independently, hydrogen, alkyl groups of one or about eighteen atoms of carbon, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven to approximately eighteen carbon atoms. And it's a non-acid group. Also disclosed are compositions and related methods

Description

AMMONIUM HYDROXIDES AS MERCAPTANO DEPURATORS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mercaptan derivatives in hydrocarbon fluids and more -particularly to the use of quaternary ammonium hydrides as mercaptan scavengers. 2. Description of the Prior Art Hydrocarbon fluids, such as crude oil, crude oil emulsions, oil field condensates, petroleum residues, and often, refined fuels still contain a variety of mercaptans, including mercaptans with a weight relatively low molecular Due to the volatility of the mercaptans with a relatively low weight, (for example, CH ^ SH methyl mercaptan, CH-CH-SH ethyl mercaptan and CH, CH2SH2SH propyl mercaptan) tend to fire vapors in some places, where their malodorous odors cause problems in the storage areas and around them, and through the pipes and in the shipping systems used to transport the hydrocarbons. To solve these problems attempts have been made using various additives. For example, it has been found that choline or choline hydroxide solves the evolution of hydrogen sulphide and the clearance of mercaptans. For example, see US patents. No. 4,594,147 granted to Roof et al., No. 4,867,865 granted to Roof and No. 5,183,560 granted to Roof et al. However, choline and hydroxide are not well suited for many uses and media such as crude oil. Although choline and choline hydroxide can purify mercaptans in such media, they also form a volatile and malodorous by-product with the sulfur compounds that occur naturally in such media. Therefore, the use of choline hydroxide choline to control odors associated with lightweight mercaptans is nullified by media such as crude oil. So the cited patents granted to Roof and Roof and co-workers fail to address this problem instead of describing the use of choline or choline hydroxide in the more refined fuel oils. European application No. 0 538 819 A3 issued to Roof et al. Describes the use of the oil-soluble quaternary ammonium compounds of the formula: to purify various sulfur compounds, including the -mercaptans, of certain oils, especially heavy residual fuels of high ebolution. These compounds, -prepared under anhydrous conditions, are those described herein as "internal ions"; that is, the positive charge on the nitrogen and the negative charge on the oxygen cause all the electrically neutral compounds, without the presence of opposite ions, such as the halides. The European application stresses the importance of the oil solubility of these compounds, none should be more oil soluble than the choline base, and they are dispersed by means of oil that is more fully treated to more effectively reduce the concentration of the compounds of undesirable sulfur. However, the compositions of the European patent application suffer from certain disadvantages. For example, compositions that are produced with high yields, and at low costs, and that reduce mercaptan concentrations more effectively are still desired, therefore, despite the reports of these techniques, the industry is still looking for other components. and methods for a more effective and efficient depuration of mercaptans with low molecular weight SHORT DESCRIPTION OF THE INVENTION The present invention, therefore, is directed to a novel method for purifying mercaptans in a hydrocarbon fluid. With the method, an effective amount of the mercaptan scavenger of a water treatment composition comprising a quaternary ammonium hydroxide is added to the fluid.The quaternary ammonium hydroxide can be re-dissolved. A -i- 1 present by the formula R R R R N OH. R and R independently are alkyl groups of one to eighteen carbon atoms, aryl groups of six to eighteen carbon atoms or alkylaryl groups of seven to eighteen carbon atoms. R 3 is an alkyl group of two to eighteen carbon atoms, an aryl group of two to eighteen carbon atoms or alkylaryl groups of seven to eighteen carbon atoms. R and 3 R can be joined to form a heterocyclic ring including N and optionally an oxygen atom. R corresponds to the formula - (CH2CH20) H, wherein n is an integer from one to about three or more, or the formula -CHR CHR Y, wherein R and R independently are hydrogen, alkyl groups of one to about eighteen atoms carbon, aryl groups of six to about eighteen carbon atoms and alkylaryl groups of seven to about eighteen carbon atoms, and Y is a non-acidic group corresponding to the formula -OH, -SR 7 or -NR7R8, wherein R7 and R8 are independently hydrogen, alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven to about eighteen carbon atoms. The present invention is also directed to a novel method for the preparation of a quaternary ammonium hydroxide. According to the method, a tertiary amine is reacted with ethylene oxide or propylene oxide, in the presence of water. The tertiary amine corresponds to the formula RRRN, where R, R and R are defined as in the preceding paragraph, and R 2 and R 3 can be joined to form a heterocyclic ring including N and optional . an oxygen atom. The method produces a quaternary ammonium hydroxide of the formula R R R R N 0 H ~, wherein R 1, R 2 and R 3 are as defined above, and wherein m is 1, 2 or 3. Among the various advantages of this invention it can be seen that the method is provided to more effectively and efficiently purify mercaptans than by conventional methods; such a method is provided for selectively purifying the light mercaptans against the heavier weight mercaptans; the method is provided so that it does not tend to generate new compositions with a bad smell; and it is also provided for making a purifying composition useful in such a method. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES In accordance with the present invention, it has been found that certain quaternary ammonium hydroxyls are surprisingly more preferred mercaptan derivatives which selectively deposit low weight mercaptans, preferably higher weight mercaptans. . The effectiveness of the hydroxides is especially surprising in view of the findings that the hydroxides are significantly more effective than the compounds that differ only by the opposite ion (ie, provided it is not hydroxide), and that in In preferred cases, the hydroxides are still more effective scavengers of the mercaptan than the corresponding internal ions (ie, R, N + R'O- in -I- _ where R-.NR 'OH OH is the preferred hydroxyde). The selectivity of the hydroxides reduces the waste that can be found unnecessarily in the scrubbers of the higher weight mercaptans, and thus allows the depuration of the less desirable mercaptans with relatively small amounts of hydroxyl. And even though, the aforesaid European patent application emphasizes the importance of the solubility of the oil of its compounds in place of its effectiveness, a superior efficiency of hydroxyls has been found in the depuration of mercaptans in hydrocarbons, although it is expected that the hydroxyls are significantly less soluble in the oil than their corresponding internal ions. In addition, it has been found that the introduction of oxygen, such as spraying the fluid treated with air, dramatically increases the purification activity. The quaternary ammonium hydroxide can be represented by the formula R1R2R3R4N + OH-. R1 and R2 independently are alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven to about eighteen carbon atoms. R 3 is an alkyl group of two to eighteen carbon atoms, an aryl group of two to about eighteen carbon atoms or alkylaryl groups of seven to about 4 to 4 cb atoms. R corresponds to the formula - (CH2H20) nH, where n is an integer from one to about three or more of the formula - (CHCH1HO) "m (CH- £ CH - - 0) nH, where CH3 and n are integers from zero to about eighteen (independently selected, except that m + n is almost approximately eighteen), or the formula -CHR CHR Y, wherein R and R independently are hydrogen, alkyl groups from one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven to about eighteen carbon atoms, and Y is a non-acidic group corresponding to the formula -OH, -SR 7 or -NR7R8, wherein R7 and R8 independently are hydrogen, alkyl groups of one to about eighteen carbon atoms, aryl groups of one to about eighteen carbon atoms or arylalkyl groups of seven to about eighteen carbon atoms. Preferably, R4 is - (CH2CH20) nH OR -CHR5CHR Y, wherein n, R, R and Y are defined as above. 1 2 3 - In the choline base, each of R, R and R is 1 2 methyl. Now it has been found that when one of R, R and 3 R is larger than methyl, you can carry out the purification still in crude oil without volatility, nor a purification with bad smell that is a byproduct of the trimethylamine generated with the use of the choline base. Therefore, R has been designated as the radical having at least two carbon atoms. In the preferred forms, 1 2 R and R are alkyl groups of eighteen or less carbon atoms and more preferably, lower alkyl groups of six carbons or less, especially three carbons or less, and optionally methyl groups. More desirably, 3 R is a fatty group, such as from eight to about -teen carbon atoms, especially from ten to about fourteen carbon atoms, such as group 3 coco. However, alternatively, R may be a benzyl group or substituted aryl groups, for example, alkylbenzyl groups, such as il-benzyl, or an alkyl group of at least two carbon atoms may be even less desirable. . In other less preferred embodiments, 2 3 R and R can be joined to form a heterocyclic ring including N and optionally an oxygen atom. In the latter case, a morpholine can be formed. It has been found that the ring products are less effective than the other products and are more difficult to prepare by the oxyalkylation of a tertiary amine. 4 R, as noted, corresponds to the formula of - (CH 2 CH 20) H, wherein n is an integer from one to about eighteen of the formula - (CH? -CiHO) I? L ÍCH £ -.CH? -O ) TíH, in don- CH3 of myn are integers from zero to about eighteen (independently selected except that m + n is almost about eighteen), or the formula -CHR CHR Y, where R and R and Y are as defined previously. It has been found that the inclusion of such R groups in the quaternary compound significantly increases the performance of the compound as a mercaptan scavenger on the termination of the quaternary tetra-alkyl compounds. In the preferred mode, R corresponds to the formula -CHR CHR Y, wherein R 5 and R 6 are hydrogen, or lower alkyls of at least six carbon atoms, especially hydrogen, and Y is -OH. However, when the quaternary compound is prepared by reacting a tertiary amine with an alkylene oxide to form a quaternary compound, wherein 4 R is -CH 2 CH 2 OH, the quaternary compounds are also formed wherein R is the ether or the polyether group - (CH 2 CH 2 O) H. Thus, a composition containing the quaternary compounds wherein R is -CH 2 CH 2 OH , often also contain quaternary compounds wherein R. is an ether or a group of the polyether - (CH ^ H ^ O) H. However, - generally, in the case that the quaternary compound is prepared by the oxyalkylation of a tertiary amine, the amine is reacted with the alkylene oxide in an approximate molar ratio of 1: 1, so that while part of the amine remains unreacted, thereby leaving part of the alkylene oxide available for the formation of the polyether, the chain that is formed of the ether and polyether typical in te is short; n is mainly one, two or three. The quaternary ammonium hydrides of this invention can be prepared by a variety of known techniques that will be readily apparent to those skilled in the art. For example, quaternary ammonium hydroxides can be prepared rapidly by the ion exchange techniques of the available quaternary ammonium halides, the quaternary ammonium halides can be passed through an ion exchange column to be extruded into an ion exchange resin. ion exchange, exchanging the halide ion for the OH ions (Y ions, where Y is as defined above and does not correspond to OH) from the column. So according to this method to produce the hydroxide, the halide R 1R2R3R4N + Z-, where R 1, R2, R3 and R4 are as defined in the above broader definition and Z is a halide, is contacted with an ion exchange resin having hydroxide ions to form the compound R 1 R 2 R 3 R 4 N + OH. Alternatively, the quaternary ammonium hydrides of this invention can be prepared by the oxy-alkylation of the tertiary amines in the presence of water. Techniques for the oxyalkylation of tertiary amines have been described, for example, in the European patent application mentioned above, but the European application needs the reaction to be carried out under anhydrous conditions. The anhydrous conditions were necessary for the formation of the internal ions of the European application. However, the benefits of hydrides have now been discovered. Such compounds are formed when oxyalkylation is carried out in the presence of water. And surprisingly it has been found that the reaction carried out in the presence of water results in yields of the quaternary ammonium hydroxide product which are significantly higher than the yields of the quaternary ammonium internal ion causing the reaction to be carried out under anhydrous conditions. In addition, carrying out the reaction in the presence of water allows the use of less oxide per amine than is necessary for the non-aqueous reaction of the European application of Roof et al. (Ie, a molar ratio of 1 may be used). : 1, in opposition to the formation of bubbles of the oxide through the amine as it was denominated by Roof and collaborators). In addition, the aqueous reaction proceeds much faster than the non-aqueous reaction proceeds and thus the quaternary product can be formed in much less time. Where Y, R 4 is a non-acidic group other than OH * a similar reaction can be carried out, for example, with an alkylene sulfide or alkylene imine instead of alkylene oxide. So the inventor of the present invention has discovered that when the oxyalkylation reaction is carried out in the presence of water, the resulting quaternary ammonium hydroxides are not only more effective scavengers of the mercaptan in certain preferred cases than are the Internal ions that have been produced having a reaction that is carried out with no water, but higher yields are also produced than those that have had internal ions. Therefore, more in detail, wherein R 4 of the quaternary ammonium hydroxide ^ R ^ N + OH "is hydroxyethyl or hydroxypropyl, or in case R 4 is an ether or a polyether group as described above, the hydroxide can be prepare by reacting a tertiary amine, such as in the form of R! R2R3N with alkylene oxide, in the presence of water.The alkylene oxide may be a propylene oxide, but ethylene oxide is preferred. preferred in which the quaternary ammonium compound is not a hydroxide, but that R 4 corresponds to the formula cecc of -CHR CHR Y, wherein R and R are defined as above and Y is a non-acidic group corresponding to the Formula -SR 7 d -NR7R8, an alkylene sulfide or alkylene imine, respectively, can be replaced by the -alkylene oxide and the same procedures can be followed.R 1, R 2 and R 3 of the tertiary amine are as defined above However, preferably R is a methyl and more preferably R 2 is also a methyl. Although R 2 and R 3 can be joined to form a heterocyclic ring including N and optionally an oxygen atom, such as to form a morpholine derivative, said compositions have been found to be more difficult to undergo an oxyalkylation without the compensation for producing more powerful debuggers, so that R 2 and R3 do not join in most desirable configurations. R 3 is preferably a fatty group of approximately six to twenty carbon atoms. The reaction is carried out in an aqueous solvent. For example, the solvent may comprise approximately 50% to 95% by weight of an alcohol, such as de-isopropyl or preferably methanol and approximately between 5% to 50% by weight of water. A typical solvent formulation, therefore, may comprise, based on weight, two parts of the solvent in relation to one part of water. The active ingredients may constitute approximately 70% by weight of the reaction mixture (the rest 30% is the solvent). In a preferred preparation method, the tertiary amine is stirred in the solvent and the system is pressurized with added alkylene oxide in a molar ratio of about 1: 1 relative to the amine. The molar ratio is generally in the approximate range between 1: 1 to 1.5: 1 of alkylene oxide relative to the amine. The reaction is typically carried out at a temperature of about 70 ° C, preferably between about 40 ° C to 50 ° C, with continuous agitation and its termination is signaled by decreasing the atmospheric pressure. The resulting mixture, in addition to the unreacted solvent, is a combination of the quaternary compounds, wherein R is the formulas -CH2CH2OH and - (CH2CH20) H, wherein n is as defined above, an unreacted amine, and the glycols formed from the reaction of alkylene oxide and water. Other ammonium hydroxides, quaternary 4, where R corresponds to the formula - (CHI ¿C | HO) m (CH ¿-CH "0) nH CH- or the formula CHR CHR Y, where m, n, R, R and Y are as defined above, and can be prepared by standard techniques, such as by injection or by simple emptying and can be dispersed throughout the fluid by agitation or other agitation. The additive is incorporated at a sufficient level to purify the mercaptans to a desired degree and will depend on the content of the mercaptans in the medium and the corresponding stoichiometry. However, typical additive levels may be in the order of about 100 to 10,000, preferably 500 to 5,000 ppm based on the weight of the medium to be treated. The medium can be any hydrocarbon fluid, preferably a liquid. For example, excellent results have been obtained for the treatment of crude oil, petroleum residues, and fuels such as kerosene. It will be recognized that while the fluids are referred to as hydrocarbon fluids, in some cases, (for example, crude oil emulsions), the hydrocarbons may comprise less than half the fluid by weight. The product is particularly useful for the treatment of crude oil in which no additional foul-smelling compound is added as has been associated with the use of choline for the treatment of crude oil. However, results superior to those achieved with the use of other compositions, such as the internal ion of the aforesaid European patent application, have been found in relation to a variety of hydrocarbon media.

In addition, it has been found that significantly greater degrees of purification result when the medium is first oxygenated, such as by aereation before the addition of the mercaptan scavenger. Although, the present inventor does not wish to be bound by a particular theory, it is considered that the mechanism by which this debugging occurs is in accordance with the following sequence of the reaction, wherein R 1 R 2 R 3 R 4 N + OH is the scavenger and RSH is mercaptan: 1 2 3 4 + - - 1 2 3 4 + RRRRN PH + RSH RS + H20 + RRR ° RN 2 RS ~ + O- RSSR (disulfide) So, improved results have been observed in increase, when the Amount of oxygen is added by aeration or by the formation of air bubbles in the medium increasing up to 100% of the stoichiometry of this reaction scheme. Furthermore, with an amount of air greater than 100%, no improved debugging has been found that is much greater than that associated with stoichiometric addition at 100%. Effective debugging at the ambient temperature of the hydrocarbon fluid can be carried out (eg, approximately 20 ° C for stored crude oil, residues or fuels), but the performance of the scrubber has been found to be improved at higher temperatures -Approximately between 50 ° C to 75 ° C. The scrubber tends to decompose even at higher temperatures, approximately such as 100 ° C. However, the decomposition at such temperatures occurs relatively slowly, while the time for the reaction between the scavenger and the mercaptans is relatively short, it usually takes only four hours to substantially reduce the mercaptan level. scrubbers can be used at such high temperatures with good results It has been found that the quaternary ammonium scavengers of this invention selectively react with the low molecular weight mercaptans, without imparting to the system their particular odor. particularly that the scrubbers clean the methyl mercaptan in preference to the ethyl mercaptan, and the methyl mercaptan in preference to the n-propyl mercaptan, and the n-propyl er-captan in preference to the n-butyl mercaptan, and thus Also, it has been observed that the scrubbers react selectively with the linear mercaptans on the branched ercaptans. So the scrubbers allow the removal of most volatile mercaptans, which are the largest contributors to odor problems, the scrubber waste is limited in collateral reactions with no less volatile mercaptans. The following examples describe the preferred embodiments of the invention. Other embodiments will be apparent within the scope of the present claims - a person skilled in the art by consideration of the specification or practice of the invention described herein. It is intended that the specification, together with the examples, be considered only in exemplary manner, the scope and spirit of the invention being indicated by the following claims after the examples. In the examples, all percentages are given based on weight unless otherwise indicated. EXAMPLE 1 A tertiary amine (ADMA C Amine, from Ethyl Coro., 77 g, 0.35 mol, methanol (92.4 g) and water (12.6 g, 0.70 mol) was placed in an adapted glass autoclave with cooling coils, an agitator , a thermal well and an ethylene oxide supply tube The reactor was sealed and the ethylene oxide (15.4 g, 0.35 mole) was added in one portion, with nitrogen to aid in the addition, immediately after the addition of the ethylene oxide, the reactor 2 had a total pressure of 1.40 kg / cm (20 psi) and a container temperature of 20 ° C. After one hour, a maximum temperature of 26 ° C. was reached. 1.12 kg / cm 2 (16 psi) after 90 minutes The product was analyzed by titration and contained 1.22meq / g of quaternary ammonium hydroxide and 0.57 meq / g of the tertiary amine.Relative yields are shown in Example 8 EXAMPLE 2 The same procedure as followed in Example 1, except that the water was omitted, an internal salt compound was prepared as it was known in the aforementioned European application granted to Roof and collaborators. Thus, 80.1 g (0.364 mole) of the amine was reacted in 96.1 g of methanol with 16.0 g (0.364 mole) of ethyl oxide. After 90 minutes, the product had 1.23 meq / g of quaternary ammonium hydroxide and 0.72 meq / g of tertiary amine. The relative yields are shown in Example 8. EXAMPLE 3. Several quaternary ammonium hydrides were prepared from the alkoxylated tertiary amines and added to the crude oil samples at 50 ° C containing 169.82 ppm of 1-propanethiol (mercaptan of propyl) and the concentrations of 1-propanothiol were measured. The results are reported in the following table, wherein each quaternary ammonium hydroxide is identified by the tertiary amine and the alkylene oxide ("ALCOXIDE", either an ethylene oxide, referred to as EtO, or a propylene oxide referred to as PrO), the concentrations of the quaternary ammonium hydroxide ("QUATERNARY CONTENT") and the unreacted amine (WITH NON-REACTIONED AMINE TAPE ") in the samples are given in equivalents of one thousandth part per gram, and the concentration of 1 -propanothiol in the sample after the treatment as measured according to ASTM D-3227 is given in ppm In Table "% REDUCTION" refers to the percentage reduction of 1-propanothiol that was achieved. CONTENT CONTENT% DE RE DO DO CUENCA DE AMINA OF 1-PROPA DUCCION TERNARIO WITHOUT REACTION No additional compound 169.82 Methyl-morpholine EtO 2.04 0.96 127.71 25 Di etilcoco EtO 1.23 0.61 119.86 29 2-hidroxietilmorfo lina EtO 0, .54 2.34 126.49 26 Di ethylbenzyl EtO 0, .812 1.624 88.26 48 Dimetilcoco PrO 0, .847 1,493 160.74 5 Methylmorpholine EtO 1. .334 1.66 75.38 56 Dimethyl Ethanol EtO 3. .85 0.40 112.55 34 Dimethyl alcohol EtO 1, .26 1.17 110.19 EXAMPLE 4 The selectivity of mercaptan of 70% ammonium hydroxide of N- (2-hydroxyethyl) -N, N-dimethyl-N-coco in a solution of isopropanol and water in crude oil at 50 ° C by GC analysis (using a specific sulfur detector) for approximately two hours after the addition of 1000 ppm of the hydroxide. A second sample of the debugger was prepared and tested in the same way. The following table shows the mercaptan content (in ppm) of the crude oil for each of the various mercaptans (identified by the type of thiol) before and after the treatment and the reduction of the corresponding percentage of this mercaptan. Io DEPURADOR 2 or MERCAPTANO DEPURADOR CONTENT CONTENT INITIAL CONTENT AFTER% OF RE AFTER RE% OF TRANSLATION OF TRANSLATION TREATMENT Methanethiol 91 21 77 52 43 Ethanethiol 85 32 62 58 32 2-Propanothiol 50 30 40 41 18 2-Methyl-2-Propa no thiol 7.3 5.4 26 6.7 8 1-Propanothiol 21 10 52 17 19 2-Butanethiol 45 32 29 41 9 EXAMPLE 5 The effectiveness of ammonium hydroxide of N- (2-hydroxyethyl) -N, N-dimethyl-N-coco was compared for the reduction of 1-propanethiol in kerosene fuel at 50 ° C with the corresponding salts with various ions opposite and with the corresponding internal salt (that is, without an opposite ion). The mercaptan content of 1-propyl (1-propanothiol) was measured 1 hour after the treatment according to ASTM D-3227.

The following results were obtained, where the thiol content is the content of 1-propanothiol provided in ppm and the% REDUCTION refers to the percentage of reduction in content achieved of 1-propanothiol. These results show an improvement better than 20% in the purification with the ammonium hydroxide of N- (2-hydroxyethyl) -N, N-dimethyl-N-co-co against the scrubber with the internal ammonium salt. of N- (2-hydroxyethyl) -N, N-dimethyl-N-coco (35% reduction of 1-pro-panothiol against 29% reduction of 1-propanothiol). CONTENT OF TIOL% OF REDUC COMPOSITION AFTER THE TRATAM. IN ADDITIONAL COMPOUND 260.7 Ammonium hydroxide N- (2-hydroxy, ethyl-N, N-dimethyl-N-coco 169.7 35 N- (2-hydroxy-ethyl) -N, N-dimethyl-N ammonium acetate -coco 229.6 12 Ammonium Chloride of N- (2-hydroxy-ethyl) -N, N-dimethyl-N-coco 259.7 0 N- (2-hydroxyethyl) -N, N-dimethyl-N-coco ammonium citrate 230.6 12 Ammonium bisulfate of N- (2-hydroxy-ethyl) -N, N-dimethyl-N-coco 259.9 0 Internal ammonium salt of N- (2-hydroxyethyl) -N, N-dimethyl-N-coco (without an opposite ion) 184.3 29 EXAMPLE 6 The effect of the presence of air was investigated by adding 3000 ppm of a solution of N- (2-hydroxyethyl) -N, N-dimethyl-N-coconut ammonium hydroxide to two samples of oil field condensates at 50 ° C, one of which was sprayed with air before the addition of the additive. The concentrations of the various mercaptans in the feed and after the treatment were measured after eight hours of storage and are given in the following table in ppm, as is the corresponding reduction percentage ("% REDUCTION"). CONTENT CONTENT% OF RE-CONTENT% OF RE OF FOOD-AFTER DUCTION AFTER THE DUCTION OF TRAFFIC. MERCAPTANO TREATMENT (WITHOUT AIR) (WITH AIR) Methanethiol 15 12 20 2 87 Ethanethiol 94 40 57 16 83 2-Propanothiol 120 72 40 56 53 2-Methyl-2-pro panothiol 61 47 23 49 20 1-Propanothiol 48 25 48 13 73 2-Butanethiol 159 108 32 92 42 2-Methyl-l-propa notiol 30 18 40 13 57 1-Butanediol 73 49 33 46 37 2-Meti1-3-butaño tiol 21 17 19 17 19 2-Pentanothiol 58 39 33 37 36 3-Pentanothiol 24 17 29 17 29 EXAMPLE 7 Ammonium hydroxide solutions of N- (2-hydroxy-1) -N, N-dimethyl-N-coconut were added to petroleum samples crude oil in test operations at room temperature from 50 ° C to 75 ° C. The initial mercaptan concentration (0 in) was measured as the mercaptan concentration at five minutes, sixty minutes and 120 minutes after the addition of the solution. The following table presents the results that provide the concentration of the additive solution and the concentrations of mercaptan ("RSH to min.") In 'ppm. Ambient Temperature 50 ° C 75 ° C Additive Concentration 1000 2000 1000 2000 10002000 RSH at 0 min 743 743 727 727 757 757 RSH to 5 min 701 640 661 645 714 549 RSH at 60 min 581 521 573 541 533 505 RSH at 120 min 518 517 458 434 420 354 EXAMPLE 8 The ladimethylcocoamine is reacted with ethylene oxide in two reactions carried out under identical conditions, except that a reaction was carried out under anhydrides, while the other was carried out in the presence of water. The resulting yield of the quaternary compound (internal salt for these preparations under anhydrous conditions and the hydroxide for these preparations in the presence of water) was measured at various times during the reaction and is presented in the following table in terms of milligrams. of KOH per gram. The internal salt prepared under anhydrous conditions is identified as "ANH" and the hydroxide prepared in the presence of water is identified as "WATER". Performance at 30 minutes Performance at 60 rain Performance at 90 minutes ANH WATER ANH WATER ANH WATER 57.3 65.0 59.4 67.6 63.1 68.1 EXAMPLE 9 Various quaternary compounds were prepared in the presence of water under anhydrous conditions by the ethoxylation of the tertiary amines. The concentrations of the resulting quaternary com pound and the unreacted amine were measured at the end of the reaction and% yield was calculated. The results are as follows, with the concentration of the quaternary compound ("QUATERNARY CONTENT") and the concentration of the unreacted amine ("NON REACTED AMPLE CONTENT") which are provided in thousandths equivalent per gram.

AMINA WATER CONTENT WHEN% REAM CONTENT WITHOUT REACTION TERNARIO CIONAR Dimetilcoco SI 1.21 0.56 68 Dimethylcoccus NO 1.27 0.62 67 Dimethylbenzyl SI 1.64 0.58 74 Dimethylbenzyl NO 1.73 0.97 64 Methylmorpholine SI 1.33 1.6 45 Methylmorpholine NO 1.45 1.87 44 Samples of the resulting compositions containing quaternary compounds were then added to kerosene at 50 ° C containing ethanethiol. The additive composition was added to the kerosene at a concentration of 500 ppm of the composition and the ethanethiol concentration was measured one hour after the addition of the composition, according to ASTM D-3227. The following results were obtained with the content of ethanethiol that is provided in ppm. AMINA WATER CONTENT OF ETHANE% OF REDUCTION DIOL WITHOUT ADDITIONAL COMPOUND 241 Dimethylcoccus SI 173 28.22 Dimetilcoco NO 177 26.56 Dimethylbenzyl SI 201 16.60 Dimethylbenzyl NO 209 13.28 Methylmorpholine SI 219 9.13 Methylmorpholine NO 205 14.94 This procedure was repeated with different amounts of the additive compositions, the selected amounts were adjusted to different levels of the quaternary compound in each composition. Sufficient composition was added in each operation to achieve a concentration of 500 ppm of assets in each test. The results were the following. AMINA WATER CURRENT DOSE CONTENT% REDUC (ppm) ETANOTIOL CION without an additional compound 241 Dimetilcoco SI 715 153 36.51 Dimetilcoco NO 681 156 35.27 Dimethylbenzyl SI 527 199 17.43 Dimethylbenzyl NO 500 205 14.94 Methylmorpholine SI 650 214 11.20 Methylmorpholine NO 597 201 16.60 EXAMPLE 10 Further experiments were carried out with the N- (2-hydroxyethyl) -N, N-dimethyl-N-coconut amino hydroxide to test the effect of oxygen. The hydroxide was added at a concentration of 2000 ppm in each of the two samples of crude oil. Before the addition, one of the samples was sprayed with air to produce an oxygen level with a stoichiometric level of 75% based on 750 ppm of the total mercaptans. The initial concentrations of the various mercaptans in the samples were measured and their concentrations were measured again after 1.5 hours of the hydroxide addition. The following results were obtained, with the concentrations given in ppm. MERCAPTANO CONTENT CONTENT 1 i% REDUC- CONTENT% INITIAL Hrs sin 02 CCION 1 hrs. REDUC with 02 CCION Methanethiol 97 69 28.87 15 84.54 Ethanethiol 75 56 25.33 22 70.67 2-Propanothiol 41 36 12.20 22 46.34 1-Propanothiol 17 14 17.65 6.7 60.59 2-Butanethiol 37 35 5.41 24 35.14 2-Methyl-l-propa notiol 3.8 3.9 0 2.1 44.74 2-Methyl-3-butanediol 3.5 3.2 8.57 2.6 25.71 2-Pentenothiol 16 15 6.25 11 31.25 3-Pentanothiol 7.7 7.4 3.90 5.9 23.38 Additional tests were carried out on the influence of oxygen with the addition of 2000 ppm of the ammonium hydroxide of N- (2-hydroxyethyl) -N, N-dimethyl-N-coco in crude oil at 50 ° C containing 200 ppm of 1-propanothiol. The test was conducted with four oil samples. No oxygen was added to one of the samples, oxygen was added at a stoichiometric level of 50% to the second sample, oxygen at a stoichiometric level of 100% was added to the third sample, and oxygen at a stoichiometric level of 200% was added. add to the remaining sample. The reduction percentage for 1-propnoltiol was determined for each sample after seven hours of the hydroxide addition with the following results. OXYGEN ADDED% REDUCTION OF 1-PROPANE-% STYCHIOMETHICAL TIOL 0 16 50 28 100 51 200 57 EXAMPLE 11 Samples were prepared in hexane containing approximately 25 ppm of MeSH, 25 ppm of EtSH and 50 ppm of PrSH. Each of the two samples was tested with an equimolar amount (approximately 300 ppm) of the quaternary compound, one with the quaternary ammonium hydroxide (Petrolite product) and the other with the internal salt, the compounds that were prepared in Examples 1 and 2, previous. An untreated preform was also prepared. The samples were heated at 60-65 ° C for one hour, analyzed by gas chromatography, allowed to stand at room temperature overnight, and analyzed again. The results are shown in the following table.

SHOWS% DISMINU% DISMINU% DIS DISTANCE TOTAL TION OF MINIMUM OF DISH MeSH EtSH OF PRSH MINIMUM RHS Internal salt, 1 hour of heating 78.7 54.3 49.8 55.2 OH Quaternary, 1 hour of heating 71.4 51.5 48.1 52.4 Internal salt , 20 hours 76.5 51.1 44.5 50.5 OH Quaternary, 20 hours 73.6 54.1 48.3 53.1 These results showed the nominal differences within the margin of experimental errors and even had the relative efficacy of the compositions. It is considered that the reduction of some values during the night was due to inaccuracies in the method, as opposed to some kind of decomposition. By virtue of the foregoing, it will be noted that various advantages of the invention are achieved and other advantages can be achieved. Various changes can be made to the above methods and compositions without departing from the spirit of the invention, it is intended that all the content comprised in the above description will be interpreted in an illustrative sense and not in a limiting sense.

Claims (19)

1. NOVELTY OF THE INVENTION Having described the invention as above, we consider what is contained in the following: CLAIMS 1. A method for purifying mercaptans in a hydrocarbon fluid, which comprises adding to the fluid an effective amount of the mercaptan scavenger of a composition of aqueous depuration comprising the quaternary ammonium hydroxide of the formula R 1 R 2 R 3 R 4 NOH, wherein R 1 and R 2 independently are selected from the group consisting of alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms, and alkylaryl groups from seven to about eighteen carbon atoms 3, and R is selected from the group consisting of the alkyl groups of two to about eighteen carbon atoms, the aryl groups of six to about eighteen carbon atoms; carbon and alkylaryl groups from seven to about eighteen carbon atoms arbono, however with the proviso that R 2 and R 3 can be joined to form a heterocyclic ring including N and optionally oxygen, and 4 R is selected from the group consisting of - (CH 2 C? LO) H wherein n is a whole of one to about eighteen carbon atoms, and -CHR CHR Y, wherein R and R independently are selected from the group consisting of hydrogen, alkyl groups of one to eighteen carbon atoms, aryl groups of six to about eighteen atoms, carbon atoms and alkylaryl groups from seven to about eighteen carbon atoms, and Y is a non-acidic group selected from the group consisting of -OH, -SR 7 and -NR7R8, in 7 8 where R and R are independently selected of the group consisting of hydrogen, alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms and alkylaryl groups of seven to about eighteen carbon atoms.
2. 2. A method as described in the claim 1, where R 2 and R3 do not join.
3. 3. A method as described in the claim 2, wherein R 4 is -CH 2 CH 2 OH.
4. 4. A method as described in the claim 3, where R is methyl.
5. 5. A method as described in claim 3, wherein each R1 and R2 are methyl.
6. 6. A method as described in claim 3, wherein R is coconut.
7. 7. A method as set forth in claim 1, wherein the hydrocarbon fluid contains some relatively low molecular weight raker-cáptans and other relatively high molecular weight mercaptans and the addition of the depuration composition causes a reduction in proportionally greater than mercaptans with a relatively low weight than mercaptans with a relatively high molecular weight.
8. A method as described in claim 3, wherein the hydrocarbon fluid contains some relatively low molecular weight mercaptans and other mercaptans with a relatively high molecular weight and the addition of the depuration composition results in a greater proportional reduction. of the mercaptans with relatively low molecular weight than the mercaptans with a relatively high molecular weight.
9. 9. A method as described in claim 1, wherein oxygen is also added to the hydrocarbon fluid.
10. 10. A method as described in claim 1, wherein the hydrocarbon fluid is crude oil.
11. 11. A method as described in claim 2, wherein the hydrocarbon fluid is crude oil.
12. 12. A method as described in claim 3, wherein the hydrocarbon fluid is crude oil.
13. 13. A method as described in claim 5, wherein the hydrocarbon fluid is crude oil.
14. 14. A method for the preparation of a quaternary ammonium hydroxide comprising reacting in the presence of water, 1 2 3 a tertiary amine of the formula RRRN, wherein R 1 and R 2 independently are selected from the group consisting of groups alkyl from one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms and alkylaryl groups of seven to about eighteen carbon atoms, and R is selected from the group consisting of alkyl groups of two to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms and alkylaryl groups of seven to about eighteen carbon atoms, however with the proviso that R 2 and R 3 can be joined to form a heterocyclic ring including N and optionally an oxygen atom, with a dioxide of alkylene of two to three carbon atoms, to produce a quaternary ammonium hydroxide 1 2 3 4 1 2 3 of the formula RRRR NOH, wherein R, R and R are defined 4 as above, and R is - (CH 2 CHO) H, wherein m is 2 or 3. CH3
15. 15. A method as described in claim 14, wherein the alkylene oxide is ethylene oxide and m is 2.
16. 16. A method as described in claim 2. cacidn 15, where R and R do not join.
17. 17. A method as described in claim 14, wherein R is methyl.
18. 18. A method as described in claim 16, wherein R 1 and R 2 are each methyl.
19. 19. A method as described in claim 18, wherein R 3 is coco. DISCLOSURE OF THE DISCLOSURE A method for the depuration of mercaptans in a hydrocarbon fluid is disclosed. According to the method, an effective mercaptan cleansing amount of an aqueous cleansing composition is added to the fluid. The composition comprises a quaternary ammonium hydroxide of the formula R'R2R3R4NOH. R1 and R2 are independently alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven about eighteen carbon atoms. R3 is an alkyl group of two to about eighteen carbon atoms, an aryl group of two to about eighteen carbon atoms or an alkylaryl group of four to about eighteen carbon atoms. R2 and R3 may be linked to form a heterocyclic ring including N and optionally an oxygen atom. R4 is - (CH2CH20) nH, where n is an integer of one to about eighteen, or -CHR5CHR6Y, wherein R5 and R6 are independently, hydrogen, alkyl groups of one to about eighteen carbon atoms, aryl groups of six to about eighteen carbon atoms or alkylaryl groups of seven to about eighteen carbon atoms. And it's a non-acid group. Related compositions and methods are also disclosed.