EA036744B1 - Synergized acetal composition and method for scavenging sulfides and mercaptans - Google Patents

Abstract

The invention describes the use of a composition comprising I. at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and II. at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, and optionally III. at least one reaction product from III(a). formaldehyde, and III(b). an amine, selected from the group consisting of primary alkyl amines having 1 to 4 carbon atoms, and primary hydroxy alkyl amines having 2 to 4 carbon atoms, and optionally IV. at least one solid 1,3,5-trithiane suppression agent selected from the group consisting of IV(a). alkaline metal salts or alkaline earth metal salts; IV(b). ammonia; alkyl, aryl or alkylaryl amines; IV(c). hydroxy alkyl, hydroxyl aryl or hydroxy alkylaryl amines; or IV(d). multifunctional amines, and IV(e). mixtures of compounds of groups IV(a) to IV(c), wherein alkyl is C1-C20-alkyl, aryl is C6-C20-aryl and alkylaryl is C7-C20-alkylaryl.

Description

The invention relates to a composition and a method for capturing (capturing) hydrogen sulfide from liquids and / or gas using a synergistic combination of acetals with a reaction product of formaldehyde and amines and a solid substance suppression agent. Formulations containing the composition of the invention are particularly well suited for trapping hydrogen sulphide and / or mercaptans while preventing the formation of undesirable emulsions and / or the precipitation of undesirable byproducts often associated with the use of chemicals and / or formulations of the prior art.

The presence of compounds containing a sulfhydryl group (—SH), and in particular hydrogen sulfide, poses problems in many industries. The presence of such compounds can pose serious health, safety and environmental problems. There are many different types of sulfhydryl group-containing compounds (sulfhydryl compounds). The most common molecules of this type include hydrogen sulfide (H2S), organosulfur compounds containing R-SH groups (also called mercaptans), thiocarboxylic acids RC (O) SH, dithiocarboxylic acids RC (S) SH, and related compounds.

In the oil and gas industry, the H2S content of crude oil and natural gas in many areas of the world is high enough to pose a threat to the environment and safety. Hydrogen sulfide is a flammable, corrosive and highly toxic gas. H ₂ S is the most reduced form of sulfur and is produced by sulfate-reducing bacteria (SRB), which are often found in anaerobic oil fields, or produced by thermal cracking and thermochemical sulfate reduction (TSR) hydrocarbons. When crude oil is produced, the pressure is released and dissolved H2S is released and then it can be transferred, for example, into the oil drilling fluid during the drilling process, and this can become hazardous as the drilling fluid is recirculated from the well to the surface. During the crude oil and natural gas recovery phase, H2S gas can pose a significant integrity risk as it is an acid gas and, when dissolved in produced water, creates a highly corrosive environment. In addition, the presence of H ₂ S increases the risk of sulfide stress corrosion cracking, hydrogen embrittlement and pitting of some structural materials, and H ₂ S requires removal for safe handling of liquids and gases.

The odor of sulfhydryl compounds is also a problem, for example in working environments associated with metal processing, but equally in water treatment processes, whether it is tap water (for example, in wastewater treatment) or industrial wastewater (for example, when recycling mine water ). SRBs are often present in fluid recirculation systems, and although bacteria can usually be controlled with biocidal compositions, biology control in the system is often lost, resulting in the formation of hazardous H2S and / or mercaptans in the system. In addition, biocides are ineffective in removing H2S after it has formed and result in only minor removal by either oxidation (for example, with sodium hypochlorite) or the release of small amounts of aldehyde during breakdown (for example, with glutaraldehyde). Sulfhydryl compounds, and especially H ₂ S, can pose environmental, toxicity and integrity problems in gaseous phases in confined spaces such as sewage treatment plants and especially in containers for the transport and storage of moisture-sensitive materials that can release H2S, which can accumulate in gas headspace. It is necessary to have an acceptor that will reduce the concentration of H ₂ S in such places.

The most commonly used acceptors of sulfhydryl compounds are based on metals such as copper, zinc or iron, which are converted to insoluble sulfides. A number of alternative non-metal methods for removing hydrogen sulfide and controlling sulfhydryl odors in hydrocarbon-containing systems have been proposed, including the following:

WO-98/02501 describes the use of bis-oxazolidines prepared by reacting 1,2 or 1,3 amino alcohols containing 3 to 7 carbon atoms with aldehydes containing 4 or fewer carbon atoms, such as 3,3'- methylenebis-5-methyloxazolidine. The relative solubility in oil and water of these products can be controlled by the choice of starting materials. These bis-oxazolidines react with sulfhydryl compounds present in oil and gas streams to neutralize them and therefore remove them;

US-5347004 describes the use of the reaction products of an alkoxyalkyleneamine, optionally in a mixture with ammonia and / or alkylamines with aldehydes to remove H ₂ S from gas streams that bubble into aqueous solutions of the reaction products;

WO-2014/031537 describes the use of an aldehyde-releasing compound, preferably hydantoin, for the removal of sulfhydryl compounds from hydrocarbon liquids;

US-3,928,211 describes the use of inorganic zinc salts (most preferably zinc carbonate), preferably dispersed in aqueous or non-aqueous oil well drilling fluids with an organic dispersant, such as lignin-containing materials, to trap hydrogen sulfide in aqueous drilling fluids;

WO-2002/051968 describes a method for reducing the level of hydrogen sulfide in a liquid or gas by forming

- 1 036744 of liquid or gas treatment with a product that binds H2S, obtained from the reaction of a compound containing a carbonyl group with an alcohol, thiol, amide, thioamide, urea or thiourea. The compound containing the carbonyl group is preferably formaldehyde, and preferably the product can be obtained by reacting formaldehyde with an amine-free alcohol or urea selected from ethylene glycol, propylene glycol, glycerin, diethylene glycol, triethylene glycol, ethyl alcohol, n-butanol, sugar, low molecular weight alcohol, castor oil fatty acid and urea. More specifically, the capture product is used with an amine, especially monoethanolamine or monoethanolamine triazine;

US-4,978,512 discloses a method for reducing H2S levels comprising contacting a medium containing H2S with, inter alia, acetals and bis-oxazolidines.

It is an object of the present invention to provide compositions that can be used to remove sulfhydryl compounds from crude oil, gas production, water production, water addition and combinations thereof, the sulfhydryl compounds being preferably H2S and / or mercaptans, but are not limited to this. Compositions according to the invention should be characterized by increased safety and efficacy compared to compositions and chemicals of the prior art, that is, they should contain low amounts of toxic substances such as formaldehyde, even after long-term storage; have higher trapping efficiency, especially for the treatment of gases such as natural gas; provide effective capture of sulfhydryl compounds in a short contact time. In addition, it is necessary to have an acceptor that does not form unwanted solid by-products and / or does not form emulsions that can inadvertently contaminate the very systems that are treated with them.

Surprisingly, it has been found that a composition comprising at least one reaction product between a monohydric alcohol and an aldehyde or ketone and at least one reaction product between a polyhydric alcohol and an aldehyde or ketone improves the trapping ability of sulfhydryl compounds compared to the reaction products of individual alcohols. Such a composition allows: (i) to reduce the acceptor dose level to obtain the same level of the residual amount of the sulfhydryl compound, and / or (ii) to achieve a lower level of the residual amount of the sulfhydryl compound with the same acceptor dose level. In addition, in combination with at least one reaction product of formaldehyde and amine (hereinafter also referred to as a synergist), the kinetics of removal of H ₂ S and / or mercaptans provided by the reaction products of a monohydric alcohol and a polyhydric alcohol with an aldehyde and / or ketone can be significantly accelerated ... Alternatively, or in addition to the first two components of the composition, the addition of a solids suppressor as an additional synergistic additive assists in the removal of sulfhydryl reaction products in continuous purification processes. In addition, this additive prolongs the breakthrough time of the sulfhydryl compound gas in the contact tower containing the reaction product of a monohydric alcohol and a polyhydric alcohol with an aldehyde and / or ketone.

The use of a synergist and / or additional synergist according to the invention allows the mixed hemiacetals and acetals to react much more efficiently with sulfhydryl compounds and especially with H2S. The mechanism that is believed to be involved in this reaction, but which should not be construed as limiting the invention in any way, is based on the likelihood that the synergistic component preferentially reacts with H2S to form an intermediate reaction complex, which then in turn reacts with a molecule of a hemiacetal, respectively an acetal, reforming the synergist molecule and releasing the corresponding alcohol present in the acetal. After the H2S removal process, the residual synergist acts as a corrosion inhibitor, protecting the integrity of pipelines and equipment in which it is used.

In the scope of this application, the expressions hemiacetal and acetal encompass the reaction products of an alcohol with either an aldehyde or a ketone, i.e. they include semi-ketals, respectively ketals, when ketones are used instead of an aldehyde in the reaction with a monohydric and / or polyhydric alcohol. The expression (semi) acetals encompasses hemiacetals, acetals and mixtures thereof, which are often formed during the reaction of alcohols and carbonyl compounds.

In a first aspect of the invention there is disclosed the use of a composition comprising:

I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and

Ii) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone to capture hydrogen sulphide and / or mercaptans.

In a second aspect of the invention, the use of a composition is disclosed comprising:

I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and

Ii) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, and

III) at least one reaction product of formaldehyde and ammonia and / or amine, selected from the group consisting of primary alkylamines having from 1 to 10 carbon atoms and primary hydro

- 2,036,744 roxyalkylamines having from 2 to 10 carbon atoms, for the capture of hydrogen sulfide and / or mercaptans.

In a third aspect, the invention discloses the use of a composition comprising:

I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and

Ii) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, and

Iii) at least one reaction product of formaldehyde and ammonia and / or amine selected from the group consisting of primary alkylamines having 1 to 10 carbon atoms and primary hydroxyalkylamines having 2 to 10 carbon atoms, and

Iv) at least one inorganic or organic alkaline compound that functions as a solid suppression agent to trap hydrogen sulfide and / or mercaptans.

In a fourth aspect of the invention, there is disclosed the use of a composition according to the first, second or third aspect of the invention as an acceptor for sulfhydryl compounds for use in oilfield operations and process systems.

In a fifth aspect of the invention, there is disclosed a method for trapping sulfhydryl compounds in oilfield operations and process systems, comprising adding to a system susceptible to release of sulfhydryl compounds the composition of the first, second or third aspect of the invention.

In a sixth aspect of the invention, the use of at least one reaction product is disclosed:

Iii) formaldehyde and ammonia and / or an amine selected from the group consisting of primary alkylamines having 1 to 10 carbon atoms and primary hydroxyalkylamines having 2 to 10 carbon atoms, as a synergist in the reaction between

a) I the product of the reaction between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and

a) II the product of the reaction between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, and

b) sulfhydryl compound.

In preferred embodiments of the invention, at least one demulsifier (V) and / or corrosion inhibitor (VI) is present in any aspect of the invention.

Group I

The Group I compound is a reaction product of a monohydric alcohol and an aldehyde or ketone. Monohydric alcohol does not contain nitrogen.

Preferred monohydric alcohols used as starting materials are alkyl, aryl and arylalkyl alcohols containing one hydroxy group and from 1 to 15 carbon atoms, more preferably from 1 to 10 carbon atoms, and especially from 2 to 5 carbon atoms, for example from 1 up to 5, 2 to 15, or 2 to 10 carbon atoms. The hydroxyl group of preferred alcohols is linked to an aliphatic, alicyclic and / or aromatic component, preferably to an aliphatic, alicyclic and / or aromatic hydrocarbon component, and more particularly to an aliphatic or cycloaliphatic component. Aliphatic and cycloaliphatic components can be saturated or unsaturated, preferably they are saturated. Aliphatic components with 3 or more carbon atoms can be linear or branched. More specifically, the monohydric alcohol can be aliphatic. In particular, the alcohol can be an alkyl alcohol. Examples of preferred alcohols are methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, tert-butanol, and various isomers of pentanol, hexanol, heptanol and octanol such as 2-ethylhexanol, and mixtures thereof. Methanol and ethanol are particularly preferred.

Preferred aldehydes or ketones used as starting materials contain one or more carbonyl groups, more preferably one or two carbonyl groups, and particularly preferably one carbonyl group. In addition, preferred aldehydes and ketones contain from 1 to 10 carbon atoms, more preferably from 1 to 7, and particularly preferably from 1 to 4 carbon atoms. In preferred aldehydes, the carbonyl group bears one, and in preferred ketones, two aliphatic, alicyclic and / or aromatic substituents, more preferably aliphatic, alicyclic and / or aromatic hydrocarbon substituents. Preferred aliphatic and cycloaliphatic substituents may be saturated or unsaturated, most preferably saturated. In ketones, both substituents can be the same or different.

In a preferred embodiment, the carbonyl compound is an aldehyde, more preferably mono- or dialdehyde, and particularly preferably formaldehyde. It should be understood that the terms aldehyde and formaldehyde include precursors such as, for example,

- 3 036744 paraformaldehyde, formalin and other chemical forms from which the basic structure of HCHO can be released during reaction with alcohol. Other suitable aldehydes include, for example, acetaldehyde, propionaldehyde, butyraldehyde, glutaraldehyde, and glyoxal. Suitable ketones include, for example, acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, hexanones, and heptanones.

If necessary, mixtures of two or more carbonyl compounds can be used, for example two or more of the aldehydes mentioned above, for example formaldehyde and one or more other aldehydes.

In the reaction between a monohydric alcohol and an aldehyde and / or ketone, some or all of the alcohols can be converted to hemiacetals and / or acetals. In a preferred embodiment, the reaction product is a hemiacetal. In a preferred embodiment, at least 50 mol% alcohol, more preferably 60 to 99 mol% alcohol, especially 65 to 95 mol% alcohol and particularly preferably 70 to 90 mol% alcohol, which corresponds, for example, more than 60 mol.%, more than 65 mol.%, more than 70 mol.% alcohol or from 50 to 99 mol.%, from 50 to 95 mol.%, from 50 to 90 mol.%, from 60 to 95 mol.% , from 60 to 90 mol.%, from 65 to 99 mol.%, from 65 to 90 mol.%, from 70 to 99 mol.%, or from 70 to 95 mol.% of alcohol, is converted into hemiacetals and / or acetals. In case the degree of conversion is low, a certain amount of unreacted monohydric alcohol remains in the composition. The presence of residual alcohol in the reaction mixture has proven to be advantageous, since the formation of a solid precipitate is often reduced during its reaction with sulfhydryl compounds. In addition, the remaining alcohol will act as a solvent.

Group II

The Group II compound is a reaction product of a polyhydric alcohol and an aldehyde or ketone. Polyhydric alcohol does not contain nitrogen.

Preferred polyhydric alcohols used as starting materials contain from 2 to 20 carbon atoms and two or more hydroxyl groups. A preferred polyhydric alcohol contains 2 to 6, more preferably 3 to 6 hydroxyl groups. Preferred polyhydric alcohols contain from 2 to 50, more preferably from 2 to 20, and especially from 3 to 10 carbon atoms, for example from 2 to 10 carbon atoms, from 3 to 50 carbon atoms, or from 3 to 20 carbon atoms. They are preferably aliphatic. Examples of preferred polyhydric alcohols are ethylene glycol, propylene glycol, butylene glycol, pentanediol, neopentyl glycol, hexanediol, glycerin, pentaerythritol, diethylene glycol, triethylene glycol, glycerol oligomer with 215 and especially 3-10 units, such as 3-15 units, such as a sugar molecule (ie, a monosaccharide or disaccharide compound); or a low molecular weight polyvinyl alcohol such that the reaction product with the carbonyl starting material remains liquid. Preferably, the number of hydroxyl groups in the polyhydric alcohol is less than or less than the number of carbon atoms. The most preferred polyols are ethylene glycol and glycerin.

Preferred aldehydes and ketones used as starting materials for Group II compounds are those already described above with respect to Group I. The most preferred aldehyde for Group II compounds is formaldehyde. The aldehyde or ketone used to react with the polyhydric alcohol can be the same as the one used for the monohydric alcohol, or it can be different.

In the reaction between a polyhydric alcohol and an aldehyde and / or ketone, some or all of the hydroxyl groups can be converted to hemiacetals and / or acetals. In a preferred embodiment, at least 50 mol% hydroxyl groups, more preferably 60 to 99 mol% hydroxyl groups, especially 65 to 95 mol% hydroxyl groups, and particularly preferably 70 to 90 mol% hydroxyl groups, for example more than 60 mol.%, more than 65 mol.%, more than 70 mol.% alcohol, or from 50 to 99 mol.%, from 50 to 95 mol.%, from 50 to 90 mol.%, from 60 to 95%, from 60 to 90 mol%, 65 to 99 mol%, 65 to 90 mol%, 70 to 99 mol%, or 70 to 95 mol% of hydroxyl groups are converted to hemiacetals and / or acetals. If the degree of conversion is low, unreacted polyhydric alcohol remains in the composition. The presence of residual hydroxyl groups in the reaction mixture turned out to be advantageous, since the formation of a solid precipitate decreases during their reaction with sulfhydryl compounds.

In a particularly preferred embodiment, the reaction product is advantageously a hemiacetal derived from a polyhydric alcohol. Particularly preferred are reaction products in which the ratio between hemiacetals and acetals on a molar basis is 50: 1 to 1:10 and preferably 20: 1 to 1: 2, for example 50: 1 to 1: 2 or 20: 1 up to 1:10.

Preferred polyhydric hemiacetal compounds that can be used as an acceptor are described by structures (2) to (5) below:

^ R _{2 (2)}

R, where R ₁ is H or C ₁ -C ₈ -alkyl, and

- 4 036744

R2 is H or CH2OH;

HO ^^ O - (CH ₂ ) _p --O - R ₂ (2a) where p is a number from 2 to 10, and

R2 is H or CH2OH;

.. / ^R4 but ₍ h)

OR ³ where R3 and R4 independently represent H or CH2OH;

_<4) o-tcH ^ where m is from 1 to 10, preferably 1 or 2.

Most preferred are structures derived from either glycerol or ethylene glycol. They correspond to formulas (3) and (4) or formula (2), where R1 is H.

In another specific preferred embodiment, the hemiacetal may have the structure below: r ₅ -o o-r ₅ ) - (CH ₂ ) _X ^ (5) r ₅ -o o-R ₅ wherein R5 is H, CH ₃ , (CH ₂ ) zCH ₃ , with the proviso that not all of R5 are hydrogen, z is from 1 to 10, and x is from 1 to 5.

The reactions of aldehydes and ketones with alcohols are described in the literature. Formaldehyde, p. 265, Joseph Frederic Walker, reprinted 1975, Robert E. Krieger Publishing Company Inc. discloses that hemiacetals are obtained when formaldehyde and alcohols are combined under neutral or basic conditions, and that they are readily formed in the case of primary and secondary alcohols.

Synthesis of Group I and Group II compounds can be separate reactions. It is preferably carried out in a simultaneous reaction using one vessel by charging a mixture of a monohydric alcohol and a polyhydric alcohol and reacting this mixture with an aldehyde and / or a ketone. The one-pot reaction is particularly preferred when the aldehyde used for the reaction with the monohydric alcohol is the same as the aldehyde used for the reaction with the polyhydric alcohol.

During the synthesis of compounds of group I and group II, the molar ratio of hydroxyl groups to carbonyl groups is preferably from 20: 1 to 1: 5, and more preferably from 10: 1 to 1: 2, and especially from 2: 1 to 1: 1, such as , from 20: 1 to 1: 2, or from 20: 1 to 1: 1, or from 10: 1 to 1: 5, or from 10: 1 to 1: 1, or from 2: 1 to 1: 5, or from 2: 1 to 1: 2.

Group III

The Group III component is optional. The group III compound is a reaction product of formaldehyde with ammonia and / or an amine, the amine being selected from the group consisting of primary alkyl amines having 1 to 10 carbon atoms and primary hydroxyalkyl amines having 2 to 10 carbon atoms. This group includes a synergistic component of the composition according to the invention.

Preferred primary amines contain 1 to 4 carbon atoms, preferred primary hydroxyamines with 2-4 carbon atoms. Particularly preferred primary hydroxyamines correspond to formula (1)

HO-A-NH2 (1) where A represents a linear or branched alkylene group with 2-4 carbon atoms.

Examples of nitrogen-containing compounds suitable for the present invention include: ammonia, methylamine, ethylamine, propylamine, isopropylamine, monoethanolamine, 1-amino-2-propanol, 3-amino-1-propanol, 2-amino-1-butanol, 3-amino-1 -butanol, 3-amino-1-butanol, 2-ethoxypropylamine, 3ethoxypropylamine, 1-methoxyisopropylamine, and 2-methoxyethylamine, but are not limited to them.

The nitrogen-containing compound and formaldehyde can be reacted in any molar ratio, with a preferred ratio of 1 mol of aldehyde per 10 mol of nitrogen-containing compound to 10 mol of aldehyde per 1 mol of nitrogen-containing compound, with a more preferred ratio of 1 mol of aldehyde per 5 mol of nitrogen-containing compound to 5 mole of aldehyde per mole of nitrogen-containing compound, with an even more preferred ratio being from 1 mole of aldehyde to 3 mole of nitrogen-containing compound to 3 mole of aldehyde per mole of nitrogen-containing compound, and the most preferred ratio being 1 mole of aldehyde to 1 mole of nitrogen-containing compound.

The structure of the aminal formed by the reaction of formaldehyde and nitrogen-containing compound depends on the selected nitrogen-containing compound and the selected molar ratio between formaldehyde and nitrogen-containing compound, which will be obvious to those skilled in the art.

Likewise, it is also possible to react a mixture of the aforementioned nitrogen-containing compounds to form separate aminals or mixtures of different aminals, which is also obvious to the average person skilled in the art.

In one preferred embodiment, the reaction product corresponds to formula (1a)

where R is H or methyl, and n is 1 or 2.

In a particularly preferred embodiment, R is CH3. In another particularly preferred embodiment, n is 1 and R is CH3. The name of this compound is 3,3'-methylenebis-5-methyl-oxazolidine (MBO).

In another preferred embodiment, the reaction product corresponds to formula (1b)

where each R ¹ is C ₁ -C ₄ -αalkyl or C ₂ -C ₄ -hydroxyalkyl. Examples of particularly preferred compounds are hexahydro-1,3,5-trimethyl-s-triazine, hexahydro-1,3,5-triethyls-triazine, hexahydro-1,3,5-tris (hydroxymethyl) -s-triazine and hexahydro- 1,3,5-tris (2-hydroxyethyl) -striazine.

Mixtures of different reaction products of structures 1a and 1b are equally suitable. The substituents R and R ¹ can be the same or different.

Group IV

The Group IV component is optional. The compound of group IV is an inorganic or organic alkaline compound. This group includes a solid suppressor.

The solid usually formed by the reaction of Group I and Group II compounds with hydrogen sulfide is 1,3,5-tritiane. The addition of an alkaline compound to the compounds of groups I and II prevents or at least slows down the formation of poorly soluble 1,3,5-trithiane when interacting with sulfhydryl compounds. Without going into theory, we believe that various intermediates, such as polyoxymethylene sulfide oligomers, are formed and stabilized due to the presence of an alkaline compound of group IV. By preventing the formation of solids, the acceptor composition remains homogeneous, and especially the use in a contact tower allows for a more efficient and quantitative use of the (semi) acetals of the compounds of groups I and II and thus a reduction in the amount of required chemicals. This can lead to an increase in gas breakthrough time in such cleaning methods. In addition, in the case of direct feed for continuous purification of sulfhydryl compounds, for example in natural gas streams, removal of liquid reaction products is much easier than removal of solids, and such reaction products do not lead to pipe fouling.

In addition, in the presence of an alkaline compound of group IV, the stability of compounds I and II is increased, and gassing of formaldehyde is reduced or even prevented. This results in a decrease in the level of free formaldehyde in the space above the composition and thus increases the safety of personnel working with the composition of the invention.

Preferably the compound of group IV is soluble or miscible with a mixture of compounds of groups I and II. In yet another preferred embodiment, the group IV compound is soluble or mixed with a mixture of the groups I and II compounds in the presence of an aqueous solvent.

In a preferred embodiment, the alkaline compound is selected from the group consisting of

IV (a). alkali metal salts or alkaline earth metal salts,

- 6 036744

IV (b). ammonia, alkyl-, aryl- or alkylarylamines,

IV (c). hydroxyalkyl-, hydroxylaryl- or hydroxyalkylarylamines,

IV (d). multifunctional amines, and

IV (e). mixtures of compounds of groups IV (a) -IV (c).

In arylamine, the N atom is bonded to the aromatic system. In an alkylarylamine, the N atom can be bonded to either an aromatic system or an alkyl group.

Preferred alkali metal and alkaline earth metal salt cations IV (a) are derived from lithium, sodium, potassium, rubidium, beryllium, magnesium, calcium and strontium, with sodium, potassium and calcium being particularly preferred. Preferred anions are hydroxyl and carbonate groups, with hydroxyl being particularly preferred. Examples of preferred alkali or alkaline earth metal salts are LiOH, NaOH, KOH, Mg (OH) 2, Ca (OH) 2, Be (OH) 2, Na2CO3, K2CO3, NaHCO3, KHCO3, BeCO3, MgCO3, CaCO3, Mg (HCO3 ^ , Ca (HCO3 ^ and mixtures thereof. Particularly preferred salts of alkali and alkaline earth metals of group IVa are NaOH, KOH, Mg (OH) 2 and Ca (OH) 2.

Group IV (b) amines can be primary, secondary or tertiary amines. Preferred amines have up to 20 carbon atoms, more preferably from 1 to 10 and especially from 2 to 4 carbon atoms, for example from 1 to 20, from 1 to 4, from 2 to 20 or from 2 to 10 carbon atoms. Preferred hydrocarbyl radicals are alkyl, aryl and alkylaryl radicals, with alkyl radicals being particularly preferred. Particularly preferred amines are alkylamines having 1 to 4 carbon atoms per alkyl radical. Examples of particularly preferred amines are methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine and butylamine.

The Group IV (c) hydroxy amine can be a primary, secondary or tertiary amine. It can contain one, two or three hydroxy groups. In a preferred embodiment, each hydrocarbyl nitrogen substituent is substituted with no more than one hydroxy group. Preferred amines have up to 20 carbon atoms, more preferably from 1 to 10 and especially from 2 to 4 carbon atoms, for example from 1 to 20, from 1 to 4, from 2 to 20 or from 2 to 10 carbon atoms. Preferred hydrocarbyl radicals are alkyl, aryl and alkylaryl radicals, with alkyl radicals being particularly preferred. Particularly preferred hydroxyamines are hydroxyalkylamines with 1 to 4 carbon atoms per alkyl moiety. Examples of particularly preferred Group IV (c) hydroxy amines are monoethanolamine, diethanolamine, 1-amino-2propanol, 3-amino-1-propanol, 2-amino-1-butanol, 3-amino-1-butanol, 2-ethoxypropylamine, 3ethoxypropylamine , 1-methoxyisopropylamine, 2-methoxyethylamine, 2- (2-aminoethoxy) ethanol, dimethylethanolamine, N-methyldiethanolamine, and monomethylethanolamine.

Preferred multifunctional amines of group IV (d) contain, in addition to the amino group, at least one additional functional group selected from the group consisting of amino groups, ether groups and acid groups or an ester, amide or salt thereof. Preferred multifunctional amines have up to 50 carbon atoms, more preferably from 1 to 20 and especially from 2 to 10 carbon atoms, for example from 1 to 50, from 1 to 10, from 2 to 50, or from 2 to 20 carbon atoms. Hydrocarbon chains can be linear, branched and / or cyclic. In a preferred embodiment, they contain from 1 to 10 and especially from 2 to 5, for example from 1 to 5 additional amino and / or ester groups. Preferably, amino and / or ether groups are separated by at least two carbon atoms. Examples of particularly preferred multifunctional amines of group IV (d) are ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, poly (ethyleneimine), propylenediamine, dipropylenetriamine, N, N-dimethyldipropylene triamine, aminoethylenepiperazine, aminoethylethanolamine; tallow fatty propylenediamine ethoxylated with 2-20 mol of ethylene oxide; oleylamine ethoxylated with 2-20 mol of ethylene oxide; morpholine and piperazine.

In another preferred embodiment, the multifunctional amines of group IV (d) contain, in addition to the amino group, an acidic group or ester, amide or salt. Preferred acidic groups are sulfonic acids, phosphoric acids, and carboxylic acids. Particularly preferred multifunctional amines carrying a carboxylic acid group are amino acids. Preferred amino acids include proteinogenic and non-proteinogenic amino acids. The amino group and the carboxylic acid group can be located on the same or different carbon atoms. Carboxylic acid groups and other acidic groups are particularly preferred in their neutralized form, for example as alkali or alkaline earth salts. Particularly preferred amino acids contain additional functional groups, including hydroxyl, carboxyl, amide, ether, guanidino, hydroxyphenyl, imidazolyl, and / or additional amino groups. Examples of preferred multifunctional amines carrying an acidic group are glycine, alanine, leucine, isoleucine, proline, serine, threonine, asparagine, glutamine, phenylalanine, tryptophan, tyrosine, valine, aspartic acid, glutamic acid, methionine, sarcosine and taurine and their carboxylate salts with sodium and / or potassium. Especially

7,036,744 preferred amino acids are glycine, lysine, histidine and arginine.

When mixtures IV (d) of alkaline compounds of groups IV (a) to IV (c) are used, they may contain 2 or more, preferably 2 to 10 and especially 3 to 5, for example two, three, four or five different components, selected from groups IV (a) -IV (c). The proportion of each individual compound in the mixture of compounds IV (a) -IV (c) is preferably 5 to 95 wt%, more preferably 10 to 90 wt% and especially 20 to 80 wt%, for example 5 to 90 wt%, 5 to 80 wt%, 10 to 95 wt%, 10 to 80 wt%, 20 to 95 wt%, or 20 to 90 wt%.

Group V

The Group V component is optional. This group includes anti-emulsifiers, demulsifiers and / or non-emulsifiers. The purpose of the presence of Group V compounds is to prevent the formation of emulsions during the cleaning process and to increase the efficiency of the cleaning process. Often metal sulfides, such as iron sulfide, are formed, for example, during corrosion of pipelines and equipment in the presence of sulfhydryl compounds. As fine solids, these substances accumulate at the oil / water interface, thereby stabilizing the water present in the oil, and forming a stable emulsion that can affect phase separation and the availability of sulfhydryl compounds to be removed. The purpose of the anti-emulsifier, demulsifier and / or non-emulsifier is to break the oil / water emulsion by creating a preferred water-moistened surface on the metal sulfide, as well as to change the surface tension at the oil / water interface, stabilized by metal sulfides, in order to coalesce the emulsion.

In a preferred embodiment, the group V anti-emulsifier is part of a composition according to the invention comprising compounds of groups I and II; groups I, II and III; groups I, II and IV or groups I, II, III and IV. Preferred anti-emulsifiers are polymeric non-ionic surfactants, including polysorbates; polymers containing ethylene oxide; polymers containing propylene oxide; copolymers of ethylene oxide and propylene oxide; alkyl polyglucosides such as decyl maltoside; but not limited to alkylphenol ethoxylates and ethoxylated and / or propoxylated alkyl phenol formaldehyde resins. The anti-emulsifier can also be a fatty alcohol alkoxylated with 1-200 mol, preferably with 2-100 mol, and especially with 5-50 mol, for example with 1-100 mol, or 1-50 mol, or 2-50 mol, or 5- 100 mol of alkylene oxide. Examples of preferred alkylene oxides are ethylene oxide, propylene oxide, and mixtures thereof; preferred fatty alcohols have a C ₄ -C ₃₆ alkyl radical and especially a C ₈ -C ₂₄ alkyl radical, for example a C ₄ -C ₂₄ alkyl radical or a C ₈ -C ₃₂ alkyl radical such as cetyl alcohol and oleyl alcohol.

In a preferred embodiment, the anti-emulsifier is a compound of formula (6)

Rn where R ₁₀ is C ₂ -C ₄ -alkylene

R11 is C ₁ -C ₁₈ alkyl k is 1 to 200 m is 1 to 100.

In a preferred embodiment, R ₁₀ is an ethylene or propylene group. R10 can be mixtures of various C ₂ -C ₄ alkylene groups, preferably ethylene and propylene groups.

In another preferred embodiment, R11 is a C ₄ -C ₁₂ alkyl group, more preferably a tertiary butyl group or an isononyl group.

In formula (6), R ₁₀ , R11 and k may be the same in each of the repeating units, or they may differ from one to one.

In another preferred embodiment, k is a number between 2 and 20.

In another preferred embodiment, m is a number between 3 and 20.

In another particular preferred embodiment, the anti-emulsifier is an alkylbenzenesulfonic acid, for example, dodecylbenzenesulfonic acid (7) or its salt with an alkali metal, ammonia or a primary, secondary or tertiary amine, such as methylamine, ethylamine, propylamine, diethylamine, dimethylaminylamine, trimethylamine, trimethylamine ethanolamine, diethanolamine, or triethanolamine.

- 8 036744 he

In another preferred embodiment, the demulsifier is a mixture of at least one compound of formula (6) and alkylbenzenesulfonic acid (7) or a salt thereof. Such a mixture preferably contains compound (6) and sulfonic acid (7) or its salt, in a mass ratio of 5: 1 to 1: 5, more preferably in a mass ratio of 3: 1 to 1: 3.

The polymeric nonionic surfactant can be added to the additional components of the composition according to the invention in pure form, or can preferably be dissolved or suspended in a solvent. Any solvent suitable for dissolving or suspending the polymeric non-ionic surfactant can be used. Examples of suitable solvents include water, ethylene glycol, propylene glycol, butylene glycol, oligoethylene glycols, oligopropylene glycols; ethers including glycol ethers such as methoxyethane, dimethoxyethane and butoxyethanol; alcohols, toluene, xylene, aromatic naphtha, or any combination thereof. The alcohol may include any alcohol suitable for use in oil recovery and for dissolving a polymeric nonionic surfactant, and may preferably be selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butanol, 2-ethylhexanol, or any of them combinations.

Group VI

The Group VI component is optional. This group includes corrosion inhibitors and serves to add corrosion inhibiting functionality to the composition of the invention. The addition of a corrosion inhibitor may not be necessary as the Group III synergist provides sufficient corrosion inhibition to protect the integrity of the overall system.

However, it is often advisable to add an additional corrosion inhibitor to reduce overall corrosivity, and to protect pipes and manufacturing equipment from corrosion caused by petroleum liquids and gases to which the present invention is applied.

A preferred embodiment of the present invention is the use of the alkyldimethylbenzylammonium chloride of formula (8) as a corrosion inhibitor which also lowers the surface tension.

R ⁹ _ 1 ₊

Cl .N-CH where R ⁹ is C ₈ -C ₁₈ alkyl.

The composition of the invention may additionally contain biocides, for example formaldehyde or glutaraldehyde, aqueous dispersants such as polyacrylamide dispersants, oxygen scavengers, antifoam agents such as acetylene diols, silicones or polyethoxylated antifoam agents, and / or flocculants. Preferably, their content is less than 10% by weight, and particularly preferably less than 5% by weight, compared to the components of groups I-VI.

In a preferred embodiment, the composition according to the invention comprises 5 to 60 wt% of the reaction product of the monohydric alcohol described above in group I, preferably 10 to 50 wt% and especially 15 to 40 wt%, for example 5 to 50 wt. %, or 5 to 40 wt%, or 10 to 60 wt%, or 10 to 40 wt%, or 15 to 60 wt%, or 15 to 50 wt%.

In a preferred embodiment, the composition according to the invention comprises 10 to 90% by weight of the reaction product of the polyhydric alcohol described in Group II above, preferably 20 to 80% by weight and especially 25 to 75% by weight, for example 10 to 80% by weight. %, or 10 to 75 wt%, or 20 to 90 wt%, or 20 to 75 wt%, or 25 to 90 wt%, or 25 to 80 wt%.

The molar ratio between the reaction product of a monohydric alcohol and an aldehyde or ketone (group I) and the reaction product of a polyhydric alcohol and an aldehyde or ketone (group II) is preferably 20: 1 to 1:20, preferably 10: 1 to 1:10, and especially 5: 1 to 1: 5, for example, 20: 1 to 1:10, 20: 1 to 1: 5, 10: 1 to 1:20, 10: 1 to 1: 5, 5: 1 up to 1:20 or from 5: 1 to 1:10.

In a preferred embodiment, the composition according to the invention contains from 0.1 to 15 wt.% Of the synergist described above in group III, preferably from 0.5 to 10 wt.% And especially from 1 to 8 wt.%, For example from 0.1 up to 10 wt.% ,. or from 0.1 to 8 wt.%. or from 0.5 to 15 wt.%, or from 0.5 to 8

- 9,036744 wt.%, Or from 1 to 15 wt.%, Or from 1 to 10 wt.%.

In a preferred embodiment, the composition according to the invention contains from 1 to 25 wt.% Of at least one suppressor of solids described above in group IV, preferably from 5 to 20 wt.% And especially from 7 to 18 wt.%, For example from 1 to 20 wt%, or 1 to wt%, or 5 to 25 wt%, or 5 to 18 wt%, or 7 to 25 wt%, or 7 to 20 wt% ...

In a preferred embodiment, the composition according to the invention contains from 0.1 to 10 wt.% Of at least one anti-emulsifier described above in group V, preferably from 0.5 to 5 wt.%.

In a preferred embodiment, the composition according to the invention comprises from 0.1 to 10% by weight of the corrosion inhibitor described in Group VI above, preferably from 0.2 to 5% by weight.

The preferred proportions of the individual compounds of groups I-VI in the composition of the invention are given in relation to the total amount of compounds of groups I-VI. In a preferred embodiment, the compounds of groups I-IV add up to 100% by weight.

The composition according to the invention is preferably used for the oil or gas to be treated in amounts of 0.5 to 50 wppm, more preferably 1 to 30 wppm and especially 2 to 20 wppm. ppm, for example 0.5 to 3 ppmw, 0.5 to 20 ppmw, 1 to 50 ppmw, 1 to 20 ppmw million, 2 to 50 wppm, or 2 to 30 wppm, per 1 ppm sulfur contained in oil or gas.

The use of the neat compositions of the invention has proven particularly successful in gas contact towers.

In a preferred embodiment, compositions according to various aspects of the invention are used in compositions further comprising water. Water in the composition can be formed during the preparation of the hemiacetals, or can be added to the composition to balance the composition. Preferably, water is present at a concentration of 1 to 90 wt%, preferably 5 to 80 wt%, for example 1 to 80 wt% or 5 and 90 wt% of the composition. In another preferred embodiment, water is present to balance up to 100 wt% of the composition.

Alternatively, any composition of the composition in accordance with various aspects of the invention is adjusted to 100% with water and / or glycol and / or alcohol based solvents in accordance with the amounts given above for water alone. Preferred alcohols and glycols are selected from, but not limited to, methanol, ethanol, propan-1-ol, propan-2-ol, ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, 2-butoxyethanol, and mixtures thereof.

The compositions according to the invention can be obtained by mixing compounds of groups I and II, groups I, II and III, groups I, II and IV, respectively, groups I, II, III and IV, each of which, if necessary, is additionally mixed with compounds of groups V and / or VI. The order in which the individual compounds are added is not important. In a preferred embodiment, compounds from groups I and II are formed simultaneously in a reaction in one vessel, and then compounds of groups III and / or IV and, if necessary, groups V and / or VI are added to them. To obtain a specific formulation, water and / or other solvents may be added to the composition of the invention. Alternatively, some or all of the components for preparing a composition of the invention may contain a solvent.

The finished formulation containing the composition according to the invention and the solvent is preferably used in concentrations of 5 to 40,000 mg / l, preferably 50 to 30,000 mg / l, especially 100 to 25,000 mg / l, for example 5 to 40,000 mg / l, from 5 to 25,000 mg / l, from 50 to 40,000 mg / l, from 50 to 25,000 mg / l, from 100 to 40,000 mg / l and from 100 to 30,000 mg / l, calculated on the volume of produced oil or gas intended for processing. The preferred and most suitable concentration of the formulation depends on the activity of the formulation itself, the type and amount of sulfhydryl compounds captured, static conditions, temperature and salinity of the system. In addition, the material class of the equipment used to operate the cleaning process should be considered: if, for example, the contact tower is made of stainless steel, a more concentrated product can be used, while it has been proven that if a poor material of construction is used, such as carbon steel it is preferred to use more dilute product formulations, preferably containing a Group VI corrosion inhibitor.

In the specified range of concentrations, the composition according to the invention provides a significant removal of sulfhydryl compounds from the obtained fluids and provides a certain sulfur content in the produced hydrocarbon as it goes to the market and, therefore, the safety of working with it. In addition, the flowability of the treated hydrocarbon is not impaired because the formation of solid reaction products is prevented.

The present invention also includes a method of using the composition of the invention to trap sulfhydryl compounds present in drilling and mineral oil production cycles, particularly as a component of workover, well servicing, production expansion and flow assurance operations.

The composition of the invention can be introduced into a stream containing the sulfhydryl compound, along with other ingredients known to those skilled in the art. Such others

- 10,036744 ingredients include acids, dispersants, thickeners, lubricants, scale inhibitors, friction reducers, crosslinking agent, surfactants, pH regulator, iron control agents, destructors; this is especially beneficial since any water produced (or reused water) is in contact with the compositions of the present invention.

The use of embodiments of the present invention allows either (i) at a lower dosage of the acceptor to obtain the same level of residual amount of sulfhydryl compound, or (ii) to achieve a lower level of residual amount of sulfhydryl compound when using the same dose of acceptor as compared to hemiacetals and / or acetals in accordance with the prior art. In addition, in combination with the reaction product of formaldehyde and amine, the kinetics of H2S and / or mercaptans uptake provided by a mixture of hemiacetals and / or acetals of a monohydric alcohol and a polyhydric alcohol with an aldehyde and / or ketone can be significantly accelerated. This allows for much more efficient trapping of sulfhydryl compounds, especially in applications where the contact time between oil or gas and the acceptor is short, such as in contact towers and direct feed applications for gas processing. The addition of a solid suppression agent as an additional synergistic additive increases the gas breakthrough time in the system containing sulfhydryl compounds. With the improvement of the capture of sulfhydryl compounds, the formation of complex and difficult to process emulsions is not observed. In addition, embodiments of the present invention will not corrode the oilfield equipment with which they are in contact and will prevent the precipitation of unwanted solids such as polymethylene sulfide oligomers and metal sulfide deposits that are often found in prior art solutions. Other applications of embodiments of the present invention include treatment of water for injection into a wellbore, treatment during drilling and process operations, altering the wettability, and cleaning the well.

Within the present description, percentages are weight percentages, unless otherwise indicated.

Examples of

Obtaining hemiacetals

In the reactor with stirring was charged with alcohols in the amount indicated in the table. 1, together with a 0.25 wt% sodium hydroxide solution of 50 wt%. This mixture was homogenized for 10 minutes before adding paraformaldehyde (93 wt.%) In the amounts indicated in table. 1 for about 30 minutes. The reaction mixture was heated with stirring for 2 h at 80 to 85 ° C. After the reaction time, the mixture was cooled to 30 ° C.

In the reaction products, the molar amounts of hemiacetals relative to the total number of charged hydroxyl groups and the content of free formaldehyde (CH2O) were determined using ¹ H-NMR spectroscopy.

Table 1. Obtaining hemiacetals and acetals

Semi- Loading reaction Reaction product acetal Monohydric alcohol, load (g) Polyhydric alcohol, load (g) Paraformaldehyde (g) (semi-) acetal CH ₂ O (wt%) A1 methanol 500 - 500 98.00% 0.07 A2 ethanol 600 - 420 99% 0.06 AZ iso-propanol 600 - 320 99% 0.08 A4 2-EG 800 - 200 98% 0.11 A5 - ethylene glycol 500 520 97% 0.12 Ab - diethylene glycol 600 360 96% 0.16 A7 - glycerol 600 410 66% 0.05 A8 - pentaerythritol 500 480 98% 0.12 A9 - pentaerythritol 600 430 75% 0.04 AU ethanol one hundred ethylene glycol 490 430 75% 0.02 AP ethanol 80 ethylene glycol 400 470 99% 0.03 A12 methanol 70 glycerol 550 450 70% 0.02 A13 methanol 80 glycerol 570 370 55% 0.02 A14 ethanol 120 glycerol 450 440 80% 0.02 A15 ethanol 160 pentaerythritol 350 440 98% 0.03

2-EG = 2-ethylhexanol

Other materials used hexahydro-1,3,5-trimethyl-s-triazine (HTT) and 3,3'-methylenebis-5-methyloxazolidine (MBO) as synergists according to group III

NaOH (5 wt% aqueous solution), triethylamine (TEA), monoethanolamine (MEA) and piperazine (PIP) were used as solid suppressors according to group IV. All of these materials were commercial.

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Testing the effectiveness of acceptors

In order to demonstrate the improved efficiency of the present invention in removing sulfhydryl compounds over Group I and Group II compounds, respectively, the removal of H2S from oil and from an oil / water mixture was measured.

The oil used was a blend of kerosene with 10% xylene with no bottom sediment and water (BS&W) to simulate oilfield conditions.

The oil and water mixture was a mixture of the above oil and brine (in a 50:50 volumetric ratio of oil to water) to mimic the performance in hydrated crude oil.

In a 500 ml autoclave (Parr reactor) 350 ml of oil, respectively, the oil / brine mixtures were deaerated for 1 h with N2, then saturated with a mixture of acid gas with 0.2 wt% H2S and 99.8 wt% CO2, blowing this gas through oil, respectively, an oil / brine mixture with a flow rate of 0.6 l / min. After equilibration with the acidic gas mixture, 1,000 ppm of the test composition was introduced into the autoclave using an HPLC pump. If mixtures of (semi) acetals were used, their mass ratios are given in table. 2 and 3; the amounts of synergist and solids suppressor are relative to their proportion in the composition and are therefore included in the indicated dosage.

Performance tests were carried out at a temperature of 30 ° C and a pressure of less than 1 bar using a gas chromatograph to measure the H2S output in the gas phase every 2 minutes. Then, the measured values of H2S content (ppm) were plotted versus time (min). The amount of hydrogen sulfide removed is the area above the resulting productivity curve, which was calculated by integrating the curve. For all samples, the curve was integrated up to 60 min after the introduction of the H2S acceptor. As an output parameter of this test, the productivity was determined by L _αkc / kg H2S (liters of H2S acceptor required to remove 1 kg of H2S from the system) for 6 min and 1 h of analysis. All consumption values are the average of three repeated tests. The test results are summarized in table. 2 and tab. 3. Percentage means the average percentage unless otherwise indicated.

Table 2. Performance Tests for H2S Acceptor in Oil (BS&W Zero)

Example (Semi) acetal Synergist (2 wt%) Solids Suppressor Lakd / KG H ₂ S 6 minutes 1 hour P1 (compare) A2 - - 20.76 9.56 P2 (cf.) AZ - - 21.23 10.04 RZ (cf.) A4 - - 32,60 16.20 P4 (compare) A5 - - 18.65 9.01 P5 (compare) Ab - - 18.09 8.47 P6 (cf.) Al + A2 (1: 1) - - 19.12 9.85 P7 (compare) A5 + Ab (2: 1) - - 17.24 8.86 P8 A2 + A5 (1: 4) - - 14.10 7.02 P9 A2 + A5 (1: 1) - - 14.48 7.35 Ryu A4 + A5 (1: 3) - - 13.86 7.13 P11 AU - - 12.95 6.89 P12 AN - - 13.22 6.70 P13 AZ + AB - - 14.27 7.54 P14 (cf.) A2 mvo - 5.65 4.63 P15 (cf.) AZ mvo - 5.86 4.86 P16 (cf.) A4 mvo - 9.98 8.05 P17 (cf.) A5 mvo - 5.10 4.21 P18 (cf.) Ab mvo - 5.28 4.36 P19 A2 + A5 (1: 4) mvo 3.10 2.72 P20 A2 + A5 (1: 1) mvo - 3.21 2.86 P21 A4 + A5 (1: 3) mvo - 3.25 2.80 P22 AU mvo - 2.98 2.61 P23 AP mvo - 2.92 2.55 P24 AZ + Ab (1: 3) mvo - 3.11 2.75 P25 (cf.) A2 mvo 5% MEA 4.76 4.06 P26 (cf.) AZ mvo 8% PIP 4.80 4.12

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P27 (cf.) A4 mvo 10% TEA 8.12 6.95 P28 (cf.) A5 mvo 5% MEA 4.29 3.68 P29 (cf.) Ab mvo 8% PIP 4.23 3.57 RZO A2 + A5 (1: 4) mvo 5% MEA 2.27 1.97 P31 A2 + A5 (1: 1) mvo 5% MEA 2.35 2.04 P32 A4 + A5 (1: 3) mvo 10% TEA 2.64 2.25 RZZ AU mvo 5% MEA 2.12 1.89 P34 AP mvo 5% MEA 2.26 2.00 R35 AZ + Ab (1: 3) mvo 8% PIP 2.49 2.21

Table 3. Performance tests for H2S removal in oil and brine mixture (50:50 volumetric ratio of oil to water phase).

Example (Semi) acetal Synergist Solids Suppressor Unit / kg H ₂ S 6 minutes 1 hour P36 (cf.) A1 - - 23.36 10.04 P37 (cf.) A2 - - 23.82 10.20 P38 (cf.) A5 - - 23.11 9.50 P39 (cf.) A7 - - 20.80 8.91 P40 (cf.) A8 - - 19.64 8.52 P41 (cf.) A9 - - 19.22 8.20 P42 A2 + A5 (1: 4) - - 15.22 6.69 P43 AU - - 15.47 6.77 P44 Al + A7 (1: 3) - - 14.96 6.61 P45 Al + A7 (1: 1) - - 15.82 6.96 P46 A12 - - 14.92 6.48 P47 A13 - - 15.44 6.88 P48 A2 + A8 (1: 1) - - 15.71 6.90 P49 A2 + A8 (1: 5) - - 14.88 6.56 P50 A2 + A9 (1: 1) - - 16.05 7.01 P51 A14 - - 14.66 6.50 P52 (cf.) A1 ntt - 8.76 7.04 P53 (cf.) A2 mvo - 8.40 6.88 P54 (cf.) A5 mvo - 8.56 6.80 P55 (cf.) A7 ntt - 9.30 7.56 P56 (cf.) A8 ntt - 8.07 6.52 P57 (cf.) A9 ntt - 8.41 6.92 P58 A2 + A5 (1: 4) mvo - 6.28 5.44 P59 AU mvo - 6.15 5.26 P60 A1 + A7 (1: 3) ntt - 6.25 5.30 P61 Al + A7 (1: 1) ntt - 6.38 5.45 P62 A12 ntt - 5.84 5.12 P63 A13 ntt - 6.50 5.78 P64 A2 + A8 (1: 1) ntt - 5.95 5.17 P65 A2 + A8 (1: 5) ntt - 5.85 5.03 P66 A2 + A9 (1: 1) ntt - 5.92 5.28 P67 A14 ntt - 6.14 5.19 P68 (cf.) A1 ntt 5% NaOH 6.91 5.72 P69 (cf.) A2 mvo 10% MEA 6.52 5.56 P70 (cf.) A5 mvo 10% MEA 7.05 5.92 P71 (cf.) A7 ntt 5% NaOH 7.33 6.24 P72 (cf.) A8 ntt 10% MEA 6.31 5.25 P73 (cf.) A9 ntt 10% MEA 6.73 5.57 P74 A2 + A5 (1: 4) mvo 10% MEA 4.42 3.86 P75 AU mvo 10% MEA 3.96 3.54 P76 Al + A7 (1: 3) ntt 5% NaOH 4.26 3.68 P77 Al + A7 (1: 1) ntt 5% NaOH 4.49 3.89 P78 A12 ntt 5% NaOH 3.93 3.47 P79 A13 ntt 5% NaOH 4.07 3.62 P80 A2 + A8 (1: 1) ntt 10% MEA 4.18 3.65 P81 A2 + A8 (1: 5) ntt 10% MEA 3.72 3.35 P82 A2 + A9 (1: 1) ntt 10% MEA 4.10 3.67 P83 A15 ntt 10% MEA 3.86 3.38 P84 A2 + A5 (1: 4) - 10% MEA 7.86 4.42 P85 AU - 10% MEA 7.73 4.28 P86 A14 ntt - 6.23 5.35 P87 A14 - 10% TEA 7.82 4.38

- 13 036744

In tests involving a synergist, the MBO ratio was 2 wt%, the HTT ratio was 6 wt% of the capture composition.

Table 2 and 3, the lower was the consumption of the acceptor to remove 1 kg of H ₂ S, the more efficient the acceptor was. In the examples of the invention, mixtures of acetals based on mixtures of monohydric alcohols and polyhydric alcohols are more effective than the individual components. Efficiency is further enhanced by the inclusion of a synergist and / or a solids suppressant. In addition, the inclusion of the synergist increases the reaction rate in the initial phase of the test, as seen from the difference in removal efficiency after 6 minutes versus 1 hour.

Acceptor Performance Tests - Gas Breakthrough

The performance of the H ₂ S acceptors of the invention was evaluated by their ability to remove H ₂ S from a flowing gas stream by passing a gas containing H2S through a liquid column containing an acceptor chemical. An acid gas mixture of 0.2% H2S and 99.8% CO2 was blown at a flow rate of 60 ml / min through 440 ml of a 22% active solution of the acceptor composition in water. Under these conditions, the average time of contact between the gas and the acceptor was about 4 s. Initially, all of the H ₂ S was removed from the gas stream and no H2S was detected in the off-gas. At some point in time (breakthrough time or TBT), the chemical was no longer able to completely capture H ₂ S from the gas stream, and H ₂ S was detected in the exhaust gas. This parameter is a measure of the effectiveness of an acceptor, especially for use in contact towers with short contact times. The longer the breakthrough time, the more effective the chemical acceptor.

The effect of the solids suppression agent was evaluated by visual inspection of the waste liquid with the acceptor after the gas breakthrough test. The degree of particulate formation was characterized as opaque> hazy> opalescent> transparent.

The total concentration of the acceptor compositions in all examples is 22 wt%, i.e. in the examples where a synergist and / or a solid suppressor is present, the concentration of (semi) acetals is reduced accordingly.

Table 4. Gas breakthrough times for various (semi) acetals.

Example (Semi) acetal Synergist Solids Suppressor TW [min] Visual analysis B1 (compare) A1 - - 31 opaque B2 (compare) A2 - - 29 opaque OT (compare) AZ - - 27 opaque B4 (cf.) A5 - - 17 opaque B5 (compare) A7 - - 35 opaque

- 14 036744

Wb (cf.) Al + A2 (1: 1) - - 31 opaque B7 (cf.) A5 + A7 (1: 1) - - 37 opaque AT 8 A2 + A5 (1: 1) - - 45 opaque AT 9 A2 + A5 (1: 4) - - 47 opaque AT 10 AU - - 52 opaque AT 11 AP - - 58 opaque AT 12 A12 - - 55 opaque B13 Al + A7 (1: 4) - - 58 opaque B14 AZ + A7 (1: 2) - - 49 opaque B15 A1 7% MVO - 76 muddy B16 A2 3% NTT - 69 muddy B17 AZ 5% NTT - 74 muddy B18 A5 3% NTT - 78 muddy B19 A7 7% MVO - 77 muddy IN 20 A2 + A5 (1: 1) 3% NTT - 82 muddy AT 21 A2 + A5 (1: 4) 3% NTT - 89 muddy B22 AU 3% NTT - 87 muddy B23 AP 3% NTT - 84 muddy B24 A12 7% MVO - 81 muddy B25 Al + A7 (1: 4) 5% MVO 85 muddy B26 AZ + A7 (1: 2) 5% NTT - 80 muddy B27 A1 - 10% MEA 149 opalescent B28 A2 - 15% PIP 146 opalescent B29 AZ - 15% PIP 134 opalescent VZO A5 - 15% PIP 157 opalescent B31 A7 - 10% MEA 150 opalescent B32 A2 + A5 (1: 1) - 15% PIP 164 opalescent VZZ A2 + A5 (1: 4) - 15% PIP 182 opalescent B34 AU - 15% PIP 169 opalescent B35 AP - 15% PIP 178 opalescent B36 A12 - 10% MEA 171 opalescent B37 Al + A7 (1: 4) - 15% PIP 172 opalescent B38 AZ + A7 (1: 2) - 15% PIP 163 opalescent B39 A1 7% MVO 10% MEA 215 transparent B40 A2 3% NTT 15% PIP 200 transparent B41 AZ 5% NTT 15% PIP 192 transparent B42 A5 3% NTT 15% PIP 226 transparent B43 A7 7% MVO 10% MEA 222 transparent B44 A2 + A5 (1: 1) 3% NTT 15% PIP 298 transparent B45 A2 + A5 (1: 4) 3% NTT 15% PIP 321 transparent B46 AU 3% NTT 15% PIP 334 transparent B47 AP 3% NTT 15% PIP 348 transparent B48 A12 7% MVO 10% MEA 342 transparent B49 Al + A7 (1: 4) 5% MVO 15% PIP 346 transparent B50 AZ + A7 (1: 2) 5% NTT 15% PIP 316 transparent

Comparison of the examples of the invention and comparative examples shows that mixtures of (semi) acetals containing reaction products of monohydric and polyhydric alcohols have a higher TBT than individual components or mixtures of components of the same group. The addition of a Group III synergist increases the H2S uptake activity of (semi) acetals and especially mixtures of (semi) acetals. The cleaning process becomes faster and more efficient. The addition of a solids suppression agent further significantly improves the performance of the acceptor. The formation of solids, which would otherwise impede the accessibility of the acceptor portion and furthermore pose a risk of plugging the effluent lines, is substantially suppressed. Increasing the removal efficiency significantly increases the stoichiometric ability of the added synergist to capture H ₂ S.

Claims (31)

CLAIM 1. Application of a composition comprising: I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and II) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, where the reaction products I and II are selected from hemiacetals and acetals, and said aldehyde or ketone containing 15 036744 contains from 1 to 10 carbon atoms, and said the monohydric alcohol contains from 1 to 15 carbon atoms, and said polyhydric alcohol contains from 2 to 20 carbon atoms and from 2 to 6 hydroxy groups, for trapping hydrogen sulfide and / or mercaptans. 2. Use according to claim 1, wherein the composition further comprises: Iii) at least one reaction product of formaldehyde and a compound selected from the group consisting of ammonia and an amine, where the amine is selected from the group consisting of primary alkylamines having from 1 to 4 carbon atoms and primary hydroxyalkylamines having from 2 to 4 carbon atoms. 3. Use according to claim 1 or 2, wherein the composition further comprises: Iv) at least one inorganic or organic alkaline compound that functions as a solid 1,3,5-trithiane suppressor. 4. Use according to one or more of claims 1 to 3, wherein the aldehyde or ketone contains from 1 to 4 carbon atoms. 5. Use according to one or more of claims 1 to 4, wherein the aldehyde is selected from the group consisting of formaldehyde, paraformaldehyde, glyoxal, acetaldehyde, propionaldehyde, butyraldehyde and glutaraldehyde. 6. Use according to any one of claims 1 to 5, wherein the aldehyde is formaldehyde. 7. Use according to one or more of claims 1 to 6, wherein the monohydric alcohol contains from 1 to 5 carbon atoms. 8. Use according to one or more of claims 1 to 7, wherein the monohydric alcohol is an aliphatic alcohol. 9. Use according to one or more of claims 1 to 8, wherein the monohydric alcohol is selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentanol, hexanol, heptanol and octanol, and any mixture of them. 10. Use according to one or more of claims 1 to 9, wherein the polyhydric alcohol is selected from the group consisting of monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, pentaerythritol, glycerol and glycerol oligomers. 11. Use according to one or more of claims 1 to 3, wherein the reaction product of a polyhydric alcohol and an aldehyde or ketone is selected from the group consisting of compounds of formulas (2) to (5): HO --- (CH ₂ ) _p --- O --- R ₂ (2a) where p is a number from 2 to 10, and R1 is H or C ₁ -C ₈ -alkyl, and R ₂ represents CH ₂ OH, and but / (3) OR ³ where R ³ and R ⁴ independently represent H or CH2OH (4) O— (CH ₂ ) _t where m is from 1 to 10, preferably 1 or 2, and r ₅ -o o — r ₅ ) --- (CH ₂ ) _X - ((5) r ₅ -o o — R ₅ where R ₅ is H, CH ₃ , (CH ₂ ) ₂ CH ₃ z is 1 to 10 x is 1 to 5. 12. The use according to one or more of claims 2 to 11, in which the product III of the reaction of the amine and formaldehyde corresponds to formula (1b) where each R ¹ is C ₁ -C ₄ -αalkyl or C ₂ -C ₄ -hydroxyalkyl. 13. The use according to one or more of claims 2 to 11, in which the product III of the reaction of the amine and formalde- - 16 036744 guides correspond to formula (1a) where R is H or methyl, and n is 1 or 2. 14. Use according to claim 13, wherein the compound of formula (1a) is 3,3'-methylenebis-5methyl-oxazolidine. 15. Use according to one or more of claims 2 to 14, wherein the reaction product III of the amine and formaldehyde is present in the composition in an amount of 1 to 20 wt%, preferably 5 to 15 wt%. 16. Use according to one or more of claims 1 to 15, wherein the composition further comprises an alkyldimethylbenzylammonium chloride of the formula (8) as a corrosion inhibitor R _ 1 ₊ Cl N — CH ₃ \ ³ ch ₃ (8) where R ⁹ is C ₈ -C ₁₈ alkyl. 17. Use according to claim 16, wherein the compound of formula (8) is present in an amount of 0.01 to 5 wt%, preferably 0.5 to 2 wt%. 18. Use according to one or more of claims 1 to 17, wherein the composition further comprises a demulsifier in an amount of 0.1 to 10 wt%, preferably 0.5 to 2 wt%. 19. The use according to claim 18, in which the demulsifier is selected from the group consisting of polysorbates, fatty alcohols; polymers including ethylene oxide; polymers including propylene oxide; copolymers of ethylene oxide and propylene oxide; alkyl polyglucosides, alkyl phenol ethoxylates, alkyl polyethylene oxide, alkyl benzene sulfonic acid, and ethoxylated and / or propoxylated alkyl phenol formaldehyde resins. 20. Use according to claim 18 or 19, wherein the demulsifier corresponds to formula (6) where R ₁₀ represents C2-C ₄ -alkylene, R11 is C ₁ -C ₁₈ alkyl, k is 1 to 200, m is 1 to 100. 21. Use according to claim 18, wherein the demulsifier is dodecylbenzenesulfonic acid. 22. The use according to one or more of claims 18-21, wherein the demulsifier is a mixture of at least one compound of formula (6) and at least one compound of formula (7) in a weight ratio of 5: 1 to 1: 5, preferably in a weight ratio of 3: 1 to 1: 3. - 17 036744 23. Use according to one or more of claims 3 to 22, wherein at least one inorganic or organic alkaline compound IV is selected from the group consisting of: IV (a) alkali metal salts or alkaline earth metal salts; IV (b) ammonia; alkyl-, aryl- or alkylarylamines; IV (c) hydroxyalkyl-, hydroxyaryl- or hydroxyalkylarylamines; IV (d) multifunctional amines containing, in addition to the amino group, at least one additional functional group selected from the group consisting of amino groups, ether groups and acid groups, and their ester, amide or salt; IV (e) mixtures of compounds from groups IV (a) -IV (c); where alkyl is C ₁ -C ₂₀ alkyl, aryl is C ₆ -C ₂₀ aryl, and alkylaryl is C ₁ -C ₂₀ alkylaryl. 24. Use according to one or more of claims 1 to 23, wherein the composition comprises 1 to 50 wt% of the reaction product of a monohydric alcohol and an aldehyde or ketone, preferably 5 to 25 wt%. 25. Use according to one or more of claims 1 to 24, wherein the composition comprises 1 to 95% by weight of the reaction product of a polyhydric alcohol and an aldehyde or ketone, preferably 20 to 75% by weight. 26. Use according to one or more of claims 3 to 25, wherein the composition comprises 0.1 to 10 wt%, preferably 0.5 to 5 wt% of at least one inorganic or organic alkaline compound as an agent suppression of solid 1,3,5-tritian. 27. Use according to one or more of claims 1 to 26, wherein the composition comprises water up to 100 wt%. 28. Use according to one or more of claims 1 to 27, wherein the capture is carried out in liquids or gases derived from subterranean formations. 29. Use according to one or more of claims 1 to 28, wherein the gas collection is carried out in a contact tower or by direct feed to the gas. 30. A method for capturing hydrogen sulfide and / or mercaptans, comprising a stage in which a composition is added to a medium containing such hydrogen sulfide or mercaptans, comprising: I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and II) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, where the reaction products I and II are hemiacetals and / or acetals, and said aldehyde or ketone contains from 1 to 10 carbon atoms, and said monohydric alcohol contains from 1 to 15 carbon atoms, and the specified polyhydric alcohol contains from 2 to 20 carbon atoms and from 2 to 6 hydroxy groups. 31. Use of a reaction product of formaldehyde and a compound selected from the group consisting of ammonia and / or amine, where the amine is selected from the group consisting of primary alkylamines having 1 to 4 carbon atoms and primary hydroxyalkylamines having 2 to 4 atoms carbon, as a synergist in the reaction between hydrogen sulfide and / or mercaptan and a composition comprising: I) at least one reaction product between a nitrogen-free monohydric alcohol and an aldehyde or ketone, and II) at least one reaction product between a nitrogen-free polyhydric alcohol and an aldehyde or ketone, where the reaction products I and II are hemiacetals and / or acetals, and said aldehyde or ketone contains from 1 to 10 carbon atoms, and said monohydric alcohol contains from 1 to 15 carbon atoms, and the specified polyhydric alcohol contains from 2 to 20 carbon atoms and from 2 to 6 hydroxy groups.