COMPOSITION OF SEQUESTRANT FOR APPLICATION TO THE ELIMINATION AND/OR REDUCTION OF HYDROGEN SULFIDE AND/OR MERCAPTANS IN FLUID

Abstract

The invention discloses a sequestrant composition for application to the elimination and/or reduction of hydrogen sulfide and/or mercaptans in fluid, particularly the reduction or elimination of hydrogen sulfide from gases and liquids, including gaseous and liquid hydrocarbons, and sewage gases, especially from natural gas and liquid hydrocarbon streams. The composition uses a main scavenger agent and sequestration rate accelerator additive that also acts as a precipitation prevention agent. The use of the composition is described as being the main scavenger agent for a 1,3-dioxolane alkyl, alkenyl and/or hydroxyl derivative and ketone-based accelerator additives that include -diketones and cyclic ketones, saturated and/or -unsaturated.

Claims

1. Composition of sequestrant for application to the elimination and/or reduction of hydrogen sulfide and/or mercaptans in fluid, wherein the composition comprises a mixture that comprises: a) from 0.01% to 99.99% by weight of at least one main sequestrant of hydrogen sulfide and/or mercaptans, that will eliminate or reduce hydrogen sulfide and/or mercaptans in solution through the formation of monothioglycol, trithiepanes and/or thioacetaldehyde derivatives (Component A); and b) from 99.99% to 0.01% by weight of at least one enhancer agent that increases the main sequestrant removal rate and that will mitigate, avoid or prevent the formation of solids and precipitates and by the subsequent generation of polysulfides through gem-thiols and/or hydroxythiols, unsaturated sulfates through enethiols and/or via dihydroxysulfides through hydroxythiols (Component B), wherein: Component A comprises a mixture of one or more 1,3-dioxolane derivatives represented by the structural formula below: ##STR00007## wherein: R and R.sup.1 independently represent H, an alkyl chain from CH.sub.3 to C.sub.6H.sub.13, a C.sub.2-C.sub.6 alkenyl chain, aryl, or alkylaryl, and R.sup.2 and R.sup.3 independently represent H, OH, an alkyl chain from CH.sub.3 to C.sub.6H.sub.13, a C.sub.2-C.sub.6 alkenyl chain, CH.sub.2OH, aryl, or alkylaryl; Component B comprises one or more ketone-type carbonyl compounds represented by the structural formula below: ##STR00008## wherein: R.sup.1 and R.sup.2 independently represent a C.sub.1-C.sub.8 alkyl chain, a C.sub.2-C.sub.8 alkenyl chain, aryl, cyclic alkenyl, hydroxy alkyl, or hydroxy alkenyl.

2. Composition according to claim 1, wherein Component A is selected from one or more of the following 1,3-dioxolane derivatives: A1) 2-ethyl 2-methyl 1,3-dioxolane-4-ol; and/or A2) 2-ethyl 2-methyl 1,3-dioxolane; and/or A3) 2,2-dimethyl 1,3-dioxolane; and Component B is selected from one or more of the following ketone derivatives: B1) 2,3-butanedione; and/or B2) cyclohexyl cyclohexanene; and/or B3) 3-methyl 3-heptene-5-one.

3. Composition according to claim 2, wherein the ratio between Component A and Component B is 50:50.

4. Composition according to claim 2, wherein the ratio between Component A and Component B is 75:25.

5. Composition according to claim 1, wherein the hydrogen sulfide and/or mercaptan sequestrant product is substantially free of water.

6. Composition according to claim 1, wherein the hydrogen sulfide and/or mercaptan sequestrant product has a pH in the range of 4 to 11.

7. A method of using a sequestrant composition to reduce or eliminate hydrogen sulfide and/or mercaptans from a gas containing water and/or liquid and/or gaseous hydrocarbons, comprising the step of introducing the sequestrant composition of claim 1 to a gas containing water and/or liquid and/or gaseous hydrocarbons, wherein the sequestrant composition reduces or eliminates hydrogen sulfide and/or mercaptans from the gas containing water and/or liquid and/or gaseous hydrocarbons.

8. A method of using a sequestrant composition to reduce or eliminate hydrogen sulfide and/or mercaptans present in aqueous solutions and/or brines and/or water/oil dispersions and/or water/oil emulsions and/or oil/water emulsions, comprising the step of introducing the sequestrant composition of claim 1 to an aqueous solution and/or brines and/or water/oil dispersions and/or water/oil emulsions and/or oil/water emulsions, wherein the sequestrant composition reduces or eliminates hydrogen sulfide and/or mercaptans from the aqueous solution and/or brines and/or water/oil dispersions and/or water/oil emulsions and/or oil/water emulsions.

9. A method of using a sequestrant composition to reduce or eliminate hydrogen sulfide and/or mercaptans from a refined fuel, comprising the step of introducing the sequestrant composition of claim 1 to a refined fuel, wherein the sequestrant composition reduces or eliminates hydrogen sulfide and/or mercaptans from the refined fuel.

10. A method of using a sequestrant composition to reduce or eliminate hydrogen sulfide and/or mercaptans from a paraffin wax and/or asphaltenes and/or bitumen and/or petroleum coke, comprising the step of introducing the sequestrant composition of claim 1 to a paraffin wax and/or asphaltenes and/or bitumen and/or petroleum coke, wherein the sequestrant composition reduces or eliminates hydrogen sulfide and/or mercaptans from the paraffin wax and/or asphaltenes and/or bitumen and/or petroleum coke.

11. A method of using a sequestrant composition to reduce, eliminate or remove hydrogen sulfide and/or mercaptans from sewage gas and/or wastewater, comprising the step of introducing the sequestrant composition of claim 1 to sewage gas and/or wastewater, wherein the sequestrant composition reduces or eliminates hydrogen sulfide and/or mercaptans from the sewage gas and/or wastewater.

12. Composition according to claim 1, wherein the sequestrant product is in aqueous solution.

13. Composition according to claim 1, wherein the sequestrant product is dissolved in a hydrocarbon.

14. Composition according to claim 1, wherein the sequestrant product is dissolved in an alcohol and/or glycol and/or mixtures thereof.

15. Composition according to claim 1, wherein the sequestrant product is dissolved in a solvent.

16. Composition according to claim 1, wherein the sequestrant product is dispersed and/or emulsified in a hydrocarbon and/or water.

17. Composition of claim 1, wherein the fluid is a stream of liquid, liquid-gas or gas containing hydrogen sulfide, sulfhydryl and/or mercaptans in solution.

18. Composition of claim 3, wherein the mixture comprises: Mixture 1: 50% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% B3 (3-methyl 3-heptene-5-one); and/or Mixture 2: 50% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% B2 (cyclohexyl cyclohexanene); and/or Mixture 3: 50% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% B1 (2,3 butanedione); and/or Mixture 4: 50% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B3 (3-methyl 3-heptene-5-one); and/or Mixture 5: 50% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B2 (cyclohexyl cyclohexanene); and/or Mixture 6: 50% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B1 (2,3 butanedione); and/or Mixture 7: 50% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B3 (3-methyl 3-heptene-5-one); and/or Mixture 8: 50% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B2 (cyclohexyl cyclohexanene) 50%; and/or Mixture 9: 50% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B1 (2,3 butanedione).

19. Composition of claim 4, wherein the mixture comprises: Mixture 1: 75% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 25% B3 (3-methyl 3-heptene-5-one); and/or Mixture 2: 75% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 25% B2 (cyclohexyl cyclohexanene); and/or Mixture 3: 75% A1 (2-ethyl 2-methyl 1,3-dioxolane) and 25% B1 (2,3 butanedione); and/or Mixture 4: 75% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B3 (3-methyl 3-heptene-5-one); and/or Mixture 5: 75% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B2 (cyclohexyl cyclohexanene); and/or Mixture 6: 75% A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B1 (2,3 butanedione); and/or Mixture 7: 75% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B3 (3-methyl 3-heptene-5-one) 25%; and/or Mixture 8: 75% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B2 (cyclohexyl cyclohexanene) 25%; and/or Mixture 9: 75% A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 25% B1 (2,3 butanedione).

20. The method of claim 9, wherein the refined fuel is a liquefied petroleum gas and/or gasoline and/or naphtha and/or kerosene and/or other hydrocarbons.

Description

DETAILED DESCRIPTION OF THE GROUNDS FOR THE INVENTION

[0024] Despite the grounds for some of the above-mentioned inventions stating that the reaction between cyclic hemiacetal derivatives such as 1,3-dioxolane and hydrogen sulfide does not occur in the same way as it does with linear hemiacetals, or even does not happen at all, and although the available literature on this type of reaction is insufficient, there are some reports describing the reaction of acetals and hydrogen sulfide as somewhat similar to hydrolysis. However, from the nature of the products formed, it is possible to define that bonds are ruptured during thiolysis by 1,3-dioxolane derivatives at the initial step in the hydrogen sulfide sequestration process.

[0025] For 1,3-dioxolane derivatives (a), the oxygen-alkylidene rupture should thus lead to the formation of (1) both mercaptan and the semitial structure (b) or its transformation product, trithioacetaldehyde, also called 2,4,6-trimethyl 1,3,5-trithiane (c). At the same time, oxygen alkyl rupture (2) should lead to acetaldehyde (d) and monothioglycol (e).

[0026] It has been found that 1,3-dioxolane derivative thiolysis in the presence of an acid catalyst is conducted mainly in the direction of (1), forming trithioacetaldehyde (c). The acetaldehyde that may be formed here probably results from the decomposition of the acetal-acid catalyst complex intermediary. The sequestration reaction described in this Invention is conducted through the formation of a highly active intermediary through carbonium ions reacting with hydrogen sulfide and sulfhydryl ions during a nucleophilic attack.

##STR00001##

[0027] The action of the sequestration potentiation additive is based on the reaction where, if hydrogen sulfide is placed in contact with a ketone (f) in the presence of a basic medium, different gem-dithiols yields are formed (g) or thioketones (h), in special cases. Particularly, gem-dithiols will be formed more easily from aldehydes than from ketones, which present steric hindrance. Gem-dithiols are cold-formed very easily from ketones in basic mediums.

##STR00002##

[0028] Where:

[0029] R=CH.sub.3 to C.sub.6H.sub.13

[0030] R=CH.sub.3 to C.sub.6H.sub.13

[0031] R=CH.sub.3; R=cyclohexyl

[0032] R=Preferably to C.sub.6H.sub.13 (including Vinyl)

[0033] R=Preferably to C.sub.6H.sub.13 (including Vinyl)

[0034] The reaction conditions for the synthesis of gem-dithiols or thioketones that are dependent on the ketone that is converted and may consequently be generalized only within a temperature range of 0 C. to 20 C., prove to be favorable; under higher temperatures, such as those encountered during oil and gas exploration and production activities (30 C. to 150 C.), heterocyclic sulfur compounds occur as secondary products.

[0035] In terms of preventing precipitation through the solubilization of hydrogen sulfide sequestration by-products using 1,3-dioxolanes and hemicetal derivatives (especially ethylene glycol hemiformal derivatives), the addition of aldehydes and especially ketones in order to produce hydroxy thiols or the corresponding conjugate acids proves efficient. As is well-known, the reaction between primary carbonyls (e.g. formaldehydes), as well as simple ketones such as acetone, ethyl methyl ketone and hydrogen sulfide leads to the formation of thioformaldehyde or its trimer s-trithiane.

[0036] Especially in the case of hemiformals such as ethylene glycol hemiformal, which may eventually eliminate hydronium ions to produce thiones (i) or thials, depending on the starting carbonyl, or trimerize directly to form trithiane (ii), hydroxythiols (v) may undergo dehydration to form enethiols (viii), followed by condensation to form unsaturated sulfides (vii) or undergo simple condensation giving rise to ,-dihydroxysulfides (ix). Ketones (iv) react with hydrogen sulfide to form hydroxythiols (v) which may in turn react again with hydrogen sulfide to produce gem-thiols (VI). Products (v) and (vi) may both be subject to spontaneous condensation generating polysulfides (iii) which continue in the organic chain without precipitating and may be eliminated during oil or gas desulfurization post-treatment processes. Under dehydration conditions, the balance will be shifted to the formation of sulfide polymers (iii) in the presence of excess hydrogen sulfide or oligomeric products (vii and ix) in the presence of carbonyls other than simple ketones and aldehydes.

##STR00003##

[0037] Preferably, the accelerator additive is based on a carbonyl compound, preferably a ketone containing 1 to 10 carbon atoms. Specifically, but not limited to ketones: acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanene, alkyl cyclohexanene, hexanenes and heptanones or ketones with to 8 carbon atoms, preferably using ketone with chains of 5 to 8 carbon atoms, saturated or unsaturated, cyclohexanenes and/or saturated or unsaturated alkyl cyclohexanenes.

SUMMARY OF THE INVENTION

[0038] This invention addresses the formulation composition of a for scavenger agent for hydrogen sulfide and/or mercaptans in gas and/or liquid streams, including gaseous and/or liquid hydrocarbons. The composition resulting from this Invention describes hydrogen sulfide sequestration by the use of the so-called main sequestrant.

[0039] This invention discloses increased kinetics in the reaction of the so-called main sequestrant caused by the presence of a enhancer agent.

[0040] The formulation resulting from this Invention discloses the sequestration of hydrogen sulfide and/or mercaptans by the main sequestrant, with faster sequestration and reductions and/or elimination of precipitate formation through concomitant use of the enhancer agent.

[0041] The formulation resulting from this Invention is comprised of the products to be called the main sequestrant, corresponding to one or more alkyl, alkenyl, cycloalkyl or cycloalkenyl derivatives or hydroxyl or alkyl hydroxyl, or 1,3-dioxolane polyhydroxyl, or alkenyl hydroxyl derivatives.

[0042] The products called enhancer agents correspond to one or more ketone derivatives of alkyl, cycloalkyl, or alkenyl and may contain one or more hydroxyl clusters and one or more unsaturations.

[0043] The formulation of product of the Invention comprises the use of at least one or more products as described in [00035], individually and/or concomitantly with at least one of the products to be called enhancer agents as described in [00036].

DISCLOSURE OF THE INVENTION

[0044] This invention relates to the composition of a high-efficiency hydrogen sulfide and/or mercaptan scavenger agent. The scavenger agent disclosed in this Invention corresponds to a product or mixture of products to be called the main sequestrant corresponding to one or more of alkyl, alkenyl and/or hydroxyl 1,3-dioxolane derivatives, to be used alone or in mixtures with products called the enhancer agent, corresponding to carbonyl derivatives of alkyl, cycloalkyl, alkenyl and/or cycloalkenyl, and may contain one or more hydroxyl clusters.

[0045] This invention provides an effective method for the rapid removal, partial reduction and/or complete elimination of hydrogen sulfide from fluids and liquid and/or gaseous streams when drilling oil and/or natural gas extraction wells; and the storage, transportation and/or treatment of acidic streams resulting from oil production and/or natural gas processes.

[0046] The product addressed by this Invention may be deployed for the elimination and/or reduction of hydrogen sulfide from hydrocarbons such as crude oil, bitumen and/or asphalt, as well as brine and/or other oil-water mixtures and/or other liquid wastes from oil and/or gas production wells and non-oil treatment streams (e.g. liquid wastes from mining, industrial drilling and other construction operations), as well as for the stowage or storage of production water, oil, gas, tars and/or any other petroleum hydrocarbons (e.g. offshore storage facilities).

[0047] The product described in this Invention is particularly suitable for the removal of hydrogen sulfide and its derivatives, including mercaptans and thiols from gas streams, and vapor space in refined oil and natural gas storage tanks, in addition to flare gases and hydrodesulfurization units, but is not limited to such applications.

[0048] The product described in this Invention is particularly suitable for the elimination of hydrogen sulfide when drilling groundwater, liquid and/or gaseous hydrocarbon wells; the production of liquid and/or gaseous hydrocarbons during liquid and/or gaseous hydrocarbons primary, secondary and enhanced recovery activities, including crude, natural gas, shale oil and shale gas, but is not limited to only such applications.

Main Sequestrant

[0049] This invention addresses the use of one or mixture of two or more 1,3-dioxolane derivatives called the main sequestrant. The main sequestrant used in this Invention includes at least one of the 1,3-dioxolane derivatives represented by the following structural formula:

##STR00004##

[0050] Where:

[0051] R and/or R=H and/or CH.sub.3 to C.sub.6H.sub.13

[0052] R=R=CH.sub.3 to C.sub.6H.sub.13 (alkyl or alkenyl, including vinyl)

[0053] R.sup.2 and/or R.sup.3=H

[0054] R.sup.2=OH

[0055] R.sup.3=OH

[0056] R.sup.2=R.sup.3=CH.sub.3 to C.sub.6H.sub.13 (alkyl or alkenyl, including vinyl)

[0057] R.sup.2 and/or R.sup.3=CH.sub.2OH

[0058] R.sup.2 and/or R.sup.3=CH, OH (n=1 and m=2n+1H) (alkyl or alkenyl, including vinyl)

[0059] R and/or R and/or R.sup.2 and/or R.sup.3=Aryl or alkylaryl

[0060] In a preferred embodiment, this Invention uses the derivatives alone or in a mixture of two or more of the following 1,3-dioxolane derivatives: 2-methyl 1,3-dioxolane and/or 2,2-dimethyl-1,3-dioxolane and/or 2-ethyl 2-methyl 1,3-dioxolane-4-ol and/or 2,2-methyl 1,3-dioxolane-4-ol and/or 2-ethyl-2-methyl 1,3-dioxolane-4-ol and/or 2-ethyl 2-methyl 1,3-dioxolane and/or 2-methyl 1,3-dioxolane and/or 4-methyl 1,3-dioxolane and/or 2-vinyl 1,3-dioxolane and/or 2-phenyl 1,3-dioxolane

[0061] In a preferred embodiment, this Invention recommends the use of the following 1,3-dioxolane derivatives: 2-ethyl 2-methyl 1,3-dioxolane-4-ol and/or 2-ethyl 2-methyl 1,3-dioxolane and/or 2,2-dimethyl 1,3-dioxolane.

[0062] The composition of the main sequestrant comprises the use of the 1,3-dioxolane derivatives mentioned in item [00043] either independently or in mixtures of two or more derivatives.

[0063] Preferably, for binary mixtures of 1,3-dioxolane derivatives (e.g. a1, a2 and a3) as disclosed in item [00045], the mixtures are comprised of possible combinations of a1a2, a2a3, a1a3 and so on, where the proportions of the derivatives may vary from 0% to 99.9%.

[0064] Preferably, for ternary mixtures of 1,3-dioxolane derivatives (e.g. a1, a2 and a3) as disclosed in item [00045], the mixtures are comprised of the possible combinations of a1, a2 and a3, where diversity of the mixture will be established by the ratio between each of the derivatives.

[0065] Preferably, 0.01% to 99.99% for a1 concentrations relative to a2 and/or a3.

[0066] Preferably, mixtures of more than three of the 1,3-dioxolane derivatives disclosed in item [00045], comprised of the possible combinations and proportions among the selected derivatives.

Additive

[0067] This invention describes the use of one or more derivatives of the so-called main sequestrants concomitantly with synergistic agents called the accelerator additives, which act together to enhance the hydrogen sulfide removal kinetics and also prevent the formation of precipitation caused by the low solubility of the products resulting from the reaction between hydrogen sulfide and the so-called main sequestrant.

[0068] The above-mentioned enhanced kinetics of the main sequestrant is taken to be that observed when compared to the removal rate in the presence of the additive.

[0069] The above-mentioned improvement to the main sequestrant kinetics in the presence of the additive is taken to be that observed when compared to other triazine-based hydrogen sulfide sequestrants or in non-cyclic hemiformals or carboxyl metal complexes.

[0070] Preferably, the so-called accelerator additives correspond to ketone-type carbonyl compounds.

[0071] Particularly, the so-called accelerator additive corresponds to ketones with 3 to 8 carbon atoms, and may be alkyl and/or alkenyl ketones (with one or more unsaturations), linear ketones and/or branched ketones, cyclic ketones, cyclic alkyl and/or alkenyl ketones, hydroxy ketones (linear, branched and/or cyclic), substituted aryl alkyl ketones and alpha-diketones.

[0072] The composition of the accelerator additive comprises use of the carbonyl compounds disclosed in item [00052] either independently or in mixtures of two or more compounds.

[0073] Preferably, the ketones indicated for use in the so-called accelerator additive include alkyl ketones (e.g. acetone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isopropylketone, butyl ethyl ketone, methyl amyl ketone, methyl hexyl ketone, methyl heptyl ketone, methyl isobutyl ketone, and/or diketones (e.g. 2,3-butanedione) and/or cyclic ketones (e.g. cyclohexanene 2-cyclohexyl cyclohexanene), and/or hydroxy ketones (e.g. 4-hydroxy 4-methyl diacetone), and/or alkyl ketones, substituted aryl (e.g. methyl naphthyl ketone) and/or alkenyl ketones (e.g. 3-methyl 3-heptene-5-one), but is not restricted solely to those listed above.

[0074] Specifically, the ketones suggested for use in the so-called accelerator additive correspond to 2,3-butanedione (b1) and/or cyclohexyl cyclohexanene (b2) and/or 3-methyl 3-heptene-5-one (b3).

[0075] Preferably, for binary mixtures of the carbonyl compounds disclosed in items [00053 and/or 00054], mixtures comprised of possible combinations of additives (b1, b2 and b3): b1b2, and b2b3 b1b3.

[0076] Preferably, for the ternary mixtures of carbonyl compounds disclosed in items [00053 and/or 00054], mixtures comprised of possible combinations of additives (b1, b2 and b3), where the diversity of each mixture will be established by the relation among each of the selected derivatives.

[0077] Preferably, for the above-mentioned mixture of three components disclosed in items [00053 and/or 00054], mixtures comprised of possible combinations of selected additives.

Formulation

[0078] The formulation composition discloses the use of an agent called the primary sequestrant and an agent called the accelerator additive.

[0079] In preferred embodiment, the formulation composition discloses the use of 1,3-dioxolane derivatives as main sequestrants and ketone-type compounds as the accelerator additives.

[0080] Preferably, the main sequestrant may be added alone or in mixtures of the so-called main sequestrants as disclosed in item [00037], concomitantly with one or more so-called accelerator additives as disclosed in items [00053 and/or 00054].

[0081] In a preferred embodiment, the compositions resulting from this Invention use the following, either alone in mixtures called the main sequestrants: 2-ethyl 2-methyl 1,3-dioxolane-4-ol (a1) and/or 2-ethyl 2-methyl 1,3-dioxolane (a2) and/or 2,2-dioxolane (a3).

[0082] Particularly, it is suggested that the product formulations of this Invention preferably use the following, either alone or in a mixture of the so-called accelerator additives: 2,3-butananedione (b1) and/or cyclohexyl cyclohexanene (b2) and/or 3-methyl 3-heptene-5-one (b3).

[0083] In a preferred embodiment, the formulation addressed by this Invention indicates the use of a main sequestrant a1, a2 or a3, together with a accelerator additive b1, b2, b3, and possible combinations thereof.

[0084] Particularly, the main sequestrant may be at concentrations of 99.99% in relation to the accelerator additive.

[0085] In a preferred embodiment, main sequestrant concentrations of more than 50% of the total formulation are suggested.

[0086] Particularly, use of the following proportions is suggested for the main sequestrant and the additive: 50:50, 60:40, 70:30, 80:20, 90:10.

[0087] In a preferred embodiment, use of the following proportions is suggested for the main sequestrant and the accelerator additive: respectively 75:25.

[0088] Countless variations are permitted within the scope of this application, thus underscoring the fact that this Invention is not limited to the particular configurations/embodiments described above.

[0089] In a particular embodiment, the formulation of the hydrogen sulfide and/or mercaptan sequestrant resulting from this Invention may use one or more 1,3-dioxolane derivatives separately from the accelerator additive.

[0090] In a recommended embodiment, the main sequestrant consisting of a 1,3-dioxolane derivative should be deployed concomitantly with the accelerator additive.

[0091] Consequently, the invention provides a sequestrant composition for application to the elimination and/or reduction of hydrogen sulfide and/or mercaptans in fluid, with fluid taken as meaning any liquid, liquid-gas or gas streams containing hydrogen sulfide, sulfhydryl and/or mercaptans in solution, characterized in that it comprises a mixture that includes: [0092] a) 0% to 99.99% by weight of at least one main sequestrant of hydrogen sulfide and/or mercaptans that will eliminate or reduce hydrogen sulfide and/or mercaptans in solution through the formation of thioacetaldehyde derivatives, monothioglycol and/or trithiepanes, to be called Component A; and [0093] b) 99.99 to 0% by weight of at least one enhancer agent that will increase the main sequestrant removal speed and mitigate, avoid or prevent the formation of solids and precipitates through the subsequent generation of polysulfides via gem-thiols and/or hydroxythiols, unsaturated sulfates via enethiols and/or via dihydroxysulfides through hydroxythiols, to be called Component B, [0094] where: [0095] at least one Component A is used, consisting of a mixture of one or more 1,3-dioxolane derivatives represented by the structural formula below:

##STR00005## [0096] whereby: [0097] R and/or R corresponds to H and/or CH.sub.3 to C.sub.6H.sub.13, and/or [0098] R or R corresponds to CH.sub.3 or C.sub.6H.sub.13 chain, which may be alkyl or alkenyl (including vinyl); and/or [0099] R.sup.2 and/or R.sup.3 corresponds to H; and/or [0100] R.sup.2 and/or R.sup.3 corresponds to OH; and/or [0101] R.sup.2 and/or R.sup.3 corresponds to CH.sub.3 to C.sub.6H.sub.13 (alkyl or alkenyl, including vinyl); and/or [0102] R.sup.2 and/or R.sup.3 corresponds to CH.sub.2OH and/or C.sub.nH.sub.mOH (n=1 and 2n+1=H) (alkyl or alkenyl, including vinyl); and/or [0103] R and/or R.sup.1 and/or R.sup.2 and/or R.sup.3=Aryl or alkylaryl; [0104] using at least one Component B, corresponding to ketone-type carbonyl compounds that include linear, branched, aromatic and/or cyclic ketones, substituted aryl alkyl ketones and alpha-diketones represented by the structural formula below:

##STR00006## [0105] in which: [0106] R.sup.1 and/or R.sup.2 correspond to the C.sub.nH.sub.2n+1, alkyl chains, preferably containing from C.sub.1 to C.sub.8; and/or [0107] R.sup.1 and/or R.sup.2 correspond to the C.sub.nH.sub.2n alkenyl chains, preferably containing C.sub.1 to C.sub.8; and/or [0108] R.sup.1 and/or R.sup.2 correspond to aryl, cyclic alkenyl, hydroxy alkyl and/or hydroxy alkenyl.

[0109] In a preferred embodiment of the composition according to the invention: [0110] Component A is preferably selected from one or more of the following 1,3-dioxolane derivatives: [0111] a1) 2-ethyl 2-methyl 1,3-dioxolane-4-ol; and/or [0112] a2) 2-ethyl 2-methyl 1,3-dioxolane; and/or [0113] a3); 2,2-dimethyl 1,3-dioxolane; and/or [0114] Component B is preferably selected from one or more of the following ketone derivatives: [0115] b1) 2,3-dutanedione; and/or [0116] b2) cyclohexyl cyclohexanene; and/or [0117] b3) 3-methyl 3-heptene-5-one.

[0118] In another preferred embodiment of the composition according to the above-mentioned invention, the ratio between Component A and Component B is 50:50, preferably but not limited to: [0119] Mixture 1: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% B3 (3-methyl 3-heptene-5-one) 50%; and/or [0120] Mixture 2: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% B2 (cyclohexyl cyclohexanene) 50%; and/or [0121] Mixture 3: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 50% b1 (2,3 butananedione) 50%; and/or [0122] Mixture 4: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B3 (3-methyl 3-heptene-5-one) 50%; and/or [0123] Mixture 5: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) 50% and b2 (cyclohexyl cyclohexanene) 50%; and/or [0124] Mixture 6: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% b1 (2,3 butananedione) 50%; and/or [0125] Mixture 7: A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% B3 (3-methyl 3-heptene-5-one) 50%; and/or [0126] Mixture 8: a3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) 50% and b2 (cyclohexyl cyclohexanene) 50%; and/or [0127] Mixture 9: A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 50% b1 (2,3 butananedione) 50%.

[0128] In another preferred embodiment of the composition according to the above-mentioned invention, the ratio between Component A and Component B is respectively 75:25, preferably but not limited to: [0129] Mixture 1: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 75% B3 (3-methyl 3-heptene-5-one) 25%; and/or [0130] Mixture 2: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 75% B2 (cyclohexyl cyclohexanene) 25%; and/or [0131] Mixture 3: A1 (2-ethyl 2-methyl 1,3-dioxolane) and 75% b1 (2,3 butananedione) 25%; and/or [0132] Mixture 4: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 75% B3 (3-methyl 3-heptene-5-one) 25%; and/or [0133] Mixture 5: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) 75% and b2 (cyclohexyl cyclohexanene) 25%; and/or [0134] Mixture 6: A2 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 75% b 1 (2,3 butananedione) 25%; and/or [0135] Mixture 7: A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 75% B3 (3-methyl 3-heptene-5-one) 25%; and/or [0136] Mixture 8: a3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) 75% and b2 (cyclohexyl cyclohexanene) 25%; and/or [0137] Mixture 9: A3 (2-ethyl 2-methyl 1,3-dioxolane-4-ol) and 75% b1 (2,3 butananedione) 25%.

[0138] In another preferred embodiment of the composition according to the above-mentioned invention, the hydrogen sulfide and/or mercaptan sequestrant product is substantially free of water.

[0139] In another preferred embodiment of the composition according to the above-mentioned invention, the hydrogen sulfide and/or mercaptan sequestrant product has a pH in the range of 4 to 11.

[0140] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is used to reduce or eliminate hydrogen sulfide and/or mercaptans from a gas containing water and/or liquid and/or gaseous hydrocarbons.

[0141] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is used to reduce or eliminate hydrogen sulfide and/or mercaptans present in aqueous solutions and/or brines and/or water/oil dispersions and/or water/oil emulsions and/or oil/water emulsions.

[0142] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is used to reduce or eliminate hydrogen sulfide and/or mercaptans from a refined fuel, including liquefied petroleum gas and/or gasoline and/or naphtha and/or kerosene and/or other hydrocarbons.

[0143] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is used to reduce or eliminate hydrogen sulfide and/or mercaptans from other refined fractions, including paraffin waxes and/or asphaltenes and/or bitumen and/or petroleum coke.

[0144] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is used to reduce, eliminate or remove hydrogen sulfide and/or mercaptans from sewage gas and/or wastewaters, including industrial and/or domestic liquid wastes.

[0145] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is in solution.

[0146] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is dissolved in a hydrocarbon.

[0147] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is dissolved in an alcohol and/or glycol and/or mixtures thereof.

[0148] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is dissolved in water.

[0149] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is dissolved in combinations of the solvents described above.

[0150] In another preferred embodiment of the composition according to the above-mentioned invention, the sequestrant product is dispersed and/or emulsified in a hydrocarbon and/or water.

[0151] In another preferred embodiment of the composition according to the above-mentioned invention, the main sequestrant described as Component A in the formulation may also be used alone as a hydrogen sulfide and/or mercaptan sequestrant, without the addition of the accelerator additive called Component B.

EXAMPLES

[0152] In all the examples, a hydrogen sulfide concentration of 100 ppm was generated in situ from Na.sub.2S.9H.sub.2O and an aqueous solution of 0.01 M NaOH pH 11. Then 100 ppm of the sequestrant or the additive or mixtures thereof were added (total concentration of main sequestrant+additive system=100 ppm). The mixtures were agitated for 1 hour at 25 C. and the final concentration of the residual H.sub.2S was measured. The residual sulfide was quantified by electrochemical titration, using a standard 0.01 M AgNO.sub.3 titrant solution and a modified Ag/Ag.sub.2S electrode. Dilutions were made using distilled water as required before quantification, with the corresponding dilution factor used subsequently. All the assays were accompanied by 100 ppm of hydrogen sulfide in a blank aqueous solution of 0.01 M NaOH pH 11 with no sequestrants or additives. Expressed as a sequestration percentage, efficiency was measured through comparing residual concentrations with the concentration defined for the blank solution with no sequestrants and/or additives.

Example 1

[0153] The sequestration capabilities of H.sub.2S scavenger agents based on 1,3-dioxolane derivatives and/or enhancer agents were compared to the capacity of standard sequestrants to remove nitrogenated (hexahydro-3,5-tris (hydroxyethyl)-s-triazine) and non-nitrogenated (1,6-dihydroxy 2,5-dioxahexane).

Example 2

[0154] The sequestration capabilities of three formulations were assessed, containing an H.sub.2S scavenger agent based on 1,3-dioxolane derivatives and an ketone-based enhancer additive in a 75:25 ratio respectively.

Example 3

[0155] The initial hydrogen sulfide sequestration rate was through sulfide removal kinetics in solution for three 1,3-dioxolane derivatives and two standard scavengers, one non-nitrogenated and one nitrogenated: (1,6 dihydroxy 2,5-dioxahexane) and (hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine, respectively. Successive samples were removed for two hours, and the residual H.sub.2O concentration was measured. Graphs were constructed for the residual concentration (ppm) x time and the initial removal rates were obtained from the resulting curves.

Example 4

[0156] The effect of an added enhancer on the initial hydrogen sulfide sequestration rate from 1,3-dioxolane derivatives was assessed in 75:25 binary mixtures of sequestrant and additive respectively. Successive samples were removed for two hours and the residual H.sub.2O concentration was measured. Graphs were constructed for the residual concentration (ppm) x time and the initial removal rates were obtained from the resulting curves.

TABLE-US-00001 TABLE 1 Hydrogen Sulfide Sequestration Efficiencies observed for 1,3-Dioxolane Derivatives. Sequestration Sequestrant Assessed Abbrev. Efficiency % 2-methyl-1,3-dioxolane 22MD 88.5 2,2-dimethyl-1,3-dioxolane 22DMD 88.9 2-ethyl-2-methyl-1,3-dioxolane-4- 2E2MDOL 90.5 methanol 2-ethyl-2-methyl-1,3-dioxolane 2E2MD 89.5 *1,6-dihydroxy-2,5-dioxahexane DHDH 88.8 **Hexahydro-1,3,5-tris(hydroxyethyl)-s- TAZ 90.9 triazine

TABLE-US-00002 TABLE 2 Hydrogen Sulfide Sequestration Efficiencies observed for ketone derivatives assessed as enhancer additives. Enhancer Additive Abbrev. Sequestration Efficiency % Methyl-ethylketone MEK 68.3 2,3-butanedione BDK 82.6 Cyclohexyl-cyclohexanene CHCK 75.8 4-hydroxy-4-methyl-pentanone 4H4MP 70.8 2-cyclohexanene 2CH 70.3 Diethylketone DEK 59.7 2-methyl-3-hydroxy-heptenone 3M3H5 73.7

TABLE-US-00003 TABLE 3 Hydrogen Sulfide Sequestration Efficiencies observed for binary mixtures deriving from 1,3-dioxolane derivatives and three ketones assessed. Main Sequestrant Enhancer additive % Sequestrant 2E2MDOL BDK 88.8 2E2MD BDK 81.3 22DM BDK 82.8 2E2MDOL CHCK 83.5 2E2MD CHCK 82.9 22DM CHCK 87.6 2E2MDOL 3M3H5 84.4 2E2MD 3M3H5 84.9 22DMD 3M3H5 93.2

TABLE-US-00004 TABLE 4 Comparison of Initial Sequestration Rates observed for four pure 1,3-dioxolane derivatives and two pure nitrogenated (**) and non-nitrogenated (*) standard sequestrants. Initial Sequestration Rate Main Sequestrant Abbrev. (ppm min.sup.1) 2-methyl-1,3-dioxolane 22MD 15.30 2,2-dimethyl-1,3-dioxolane 22DMD 15.06 2-ethyl-2-methyl-1,3-dioxolane-4- 2E2MDOL 18.80 methanol 2-ethyl-2-methyl-1,3-dioxolane 2E2MD 17.53 *1,6-dihydroxy-2,5-dioxahexane DHDH 15.03 **Hexahydro-1,3,5-tris(hydroxyethyl)-s- TAZ 17.56 triazine

TABLE-US-00005 TABLE 5 Increases in Initial Sequestration Rates observed for binary mixtures with three 1,3-dioxolane derivatives and three ketones assessed. Main Enhancer Initial Sequestration Increase in initial Sequestrant Additive Rate (ppm min.sup.1) Sequestration Rate % 2E2MDOL BDK 22.55 16.64 2E2MD BDK 22.08 20.61 22DMD BDK 22.17 32.10 2E2MDOL CHCK 22.22 15.40 2E2MD CHCK 22.18 20.96 22DMD CHCK 22.47 33.00 2E2MDOL 3M3H5 22.30 15.72 2E2MD 3M3H5 22.27 21.30 22DMD 3M3H5 22.82 34.03