Hydrogen sulphide and mercaptans scavenging compositions

1. A composition for scavenging hydrogen sulphide and mercaptans in hydrocarbon streams, said composition comprising an oxazolidine compound and an additive,

the additive being the reaction product of a compound (A) with a compound (B), optionally followed by a quaternization reaction of the reaction product of (A) and (B) with a compound (C), wherein the weight ratio of oxazolidine compound(s) to said additive(s) ranges from 1 to 100,

wherein:

Compound (A) is a polyisobutenyl succinic anhydride (PIBSA),

Compound (C) is a quaternizing agent, and

Compound (B) is selected from:

primary polyamines of formula (II):

H 2 N—[(CHR 3 —(CH 2 ) p —CHR 4 ) q —NH] m —H

wherein:

R 3 and R 4 , which are identical or different, represent hydrogen or an alkyl or alkenyl group comprising from 1 to 4 carbon atoms,

q is an integer varying from 1 to 3,

m is an integer varying from 1 to 10 and

p is an integer equal to 0 or 1;

or

from the group consisting of: N,N-dimethylaminopropylamine, N,N,N-tris(aminoethyl)amine, N,N-dibutylaminopropylamine, N,N-diethylaminopropylamine, N,N-dimethylaminoethylamine, 1-(3-aminopropyl)imidazole, 4-(3-aminopropyl) morpholine, 1-(2-aminoethyl)piperidine, 3,3-diamino-N-methyldipropylamine, and 31 3 -bisamino(N,N-dimethylpropylamine), and N′-(3-(dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine.

2. The composition according to claim 1 , wherein the quaternizing agent (C) is selected from the group constituted by the dialkyl sulphates, the carboxylic acid esters; the alkyl halides, the benzyl halides, the hydrocarbon carbonates, and the hydrocarbon epoxides optionally mixed with an acid, alone or in a mixture.

3. The composition according to claim 1 , wherein said additive comprises: compound (i) the reaction product of a compound (A) with a compound (B).

4. The composition according to claim 1 , wherein the composition comprises from 19 to 99% wt of oxazolidine compound(s) and from 1 to 50% wt of said additive(s), based on the total weight of the composition.

5. The composition according to claim 1 , wherein the weight ratio of oxazolidine compound(s) to said additive(s) ranges from 1 to 50.

6. The composition according to claim 1 , further comprising a solvent.

7. The composition according to claim 6 , wherein the solvent is present in an amount ranging from 1 to 80% wt, based on the total weight of the composition.

8. The composition according to claim 1 , comprising:

from 19 to 80% wt of oxazolidine compound(s),

from 1 to 30% wt of said additive(s), and

from 1 to 80% wt of solvent(s), based on the total weight of the composition.

9. Process for improving the efficiency of an oxazolidine compound for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, the process comprising a step of adding the additive defined in claim 1 in an oxazolidine compound, wherein the weight ratio of oxazolidine compound to said additive ranges from 1 to 100.

10. Hydrocarbon stream comprising hydrocarbons and a composition according to claim 1 .

11. Hydrocarbon stream according to claim 10 , wherein the hydrocarbons are selected from crude oil, fuel oil, fuel, Light Petroleum Gas and natural gas.

12. A method for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, comprising contacting the hydrocarbon stream with the composition according to claim 1 .

13. The composition according to claim 1 , wherein compound (B) is selected from primary polyamines of formula (II).

14. A composition for scavenging hydrogen sulphide and mercaptans in hydrocarbon streams, said composition comprising an oxazolidine compound and an additive,

the additive being the reaction product of a compound (A) with a compound (B), followed by a quaternization reaction of the reaction product of (A) and (B) with a compound (C), wherein the weight ratio of oxazolidine compound(s) to said additive(s) ranges from 1 to 100, wherein:

Compound (A) is a hydrocarbyl-substituted acylating agent,

Compound (C) is a quaternizing agent,

Compound (B) is an alkanolamine comprising one hydroxyl function, one primary amine function, and one tertiary function and from 4 to 16 carbon atoms.

15. The composition according to claim 14 , wherein:

Compound (A) is a polyisobutenyl succinic anhydride (PIBSA),

Compound (B) is an alkanolamine comprising one hydroxyl function, one primary amine function and one tertiary amine function and from 4 to 16 carbon atoms,

Compound (C) is a quaternizing agent.

16. A composition for scavenging hydrogen sulphide and mercaptans in hydrocarbon streams, said composition comprising an oxazolidine compound and an additive, the additive comprising:

(i) a reaction product of a compound (A) with a compound (B), wherein:

Compound (A) is a polyisobutenyl succinic anhydride (PIBSA),

Compound (B) is a nitrogen-containing compound formula (II):

H 2 N—[(CHR 3 —(CH 2 ) p —CHR 4 ) q —NH] m —H

wherein:

R 3 and R 4 , which are identical or different, represent hydrogen or an alkyl or alkenyl group comprising from 1 to 4 carbon atoms,

q is an integer varying from 1 to 3,

m is an integer varying from 1 to 10 and

p is an integer equal to 0 or 1,

or

(ii) a reaction product of a compound (A) with a compound (B), followed by a quaternization reaction of the reaction product of (A) and (B) with a compound (C), wherein:

Compound (A) is a polyisobutenyl succinic anhydride (PIBSA),

Compound (B) is an alkanolamine comprising one hydroxyl function, one primary amine function and one tertiary amine function and from 4 to 16 carbon atoms,

Compound (C) is a quaternizing agent,

wherein the composition comprises from 19 to 99% wt of oxazolidine compound(s) and from 1 to 50% wt of said additive(s), based on the total weight of the composition, and wherein the oxazolidine compound is selected from bisoxazolidines having a structure of formula (I):

wherein

n is an integer ranging from 1 to 6; and

R1 and R2, identical or different, are selected from a hydrogen atom and a linear, branched or cyclic alkyl or alkenyl groups having from 1 to 6 carbon atoms.