Primary amine-containing polymers useful as scale inhibitors

Patent metadata

Field	Value
Publication number	US-9902617-B2
Application number	US-201514620083-A
Country	US
Kind code	B2
Filing date	Feb 11, 2015
Priority date	Feb 11, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer, or salt thereof, to one or more stages of a wet process phosphoric acid production stream are provided herein, wherein the primary amine-containing polymer includes an A mer according to Formula (I):

where
R is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, halide, or carboxyl;
R 1 is H, C 1 -C 6 alkyl, or C 2 -C 6 alkenyl;
R 2 is H or an A mer according to Formula (I) as herein defined;
R 3 is chosen from a direct bond or a C 1 -C 12 alkyl, C 2 -C 12 alkenyl, or a C 6 -C 12 aryl group; and
n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and

wherein the percentage of primary amines in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

First claim

We claim:

1. A process for inhibiting scale produced during wet process phosphoric acid production, the process comprising:
adding a scale-inhibiting amount of a reagent comprising a primary amine-containing polymer, or salt thereof, to at least one stage of a wet process phosphoric acid production process,

wherein said primary amine-containing polymer comprises an A mer according to Formula (I):

where
R is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, halide, or carboxyl;
R 1 is H, C 1 -C 6 alkyl, or C 2 -C 6 alkenyl;
R 2 is H or an A mer according to Formula (I);
R 3 is chosen from a direct bond or a C 1 -C 12 alkyl, C 2 -C 12 alkenyl, or a C 6 -C 12 aryl group; and
n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and

wherein the percentage of primary amine in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

2. A process according to claim 1 , wherein R and R 1 are H, and R 3 is a direct bond.

3. A process according to claim 1 , wherein the primary amine-containing polymer is a polyvinylamine homopolymer, or a salt thereof.

4. A process according to claim 1 , wherein R and R 1 are H, and R 3 is CH 2 .

5. A process according to claim 1 , wherein the primary amine-containing polymer is a polyallylamine homopolymer, or a salt thereof.

6. A process according to claim 5 , wherein the polyallylamine homopolymer salt is polyallylamine-hydrochloride.

7. A process according to claim 1 , wherein the primary amine-containing polymer further comprises a B mer.

8. A process according to claim 7 , wherein R 3 of said A mer is a direct bond, said B mer unit comprises a compound according to Formula (II):

wherein
R and R 1 are as defined for the A mer according to Formula (I);
R 4 is chosen from H or C 1 -C 4 alkyl;
R 5 is a direct bond or a C 1 -C 12 alkyl; C 2 -C 12 alkenyl, or a C 6 -C 12 aryl group;
R 6 is a C 1 -C 22 alkyl, C 2 -C 22 alkenyl, or C 6 -C 22 aryl group, which group is optionally substituted at one or more substitutable position
n is chosen from 30 mole % to 99 mole % based on the total percentage of mer units in the polymer; and
m is chosen from 1 mole % to 70 mole % based on the total percentage of mer units in the polymer.

9. A process according to claim 8 , wherein the B mer unit according to Formula (II) is

10. A process according to claim 7 , wherein the B mer is derived from a monomer selected from the group consisting of diallylamine, diallyldimethylammonium chloride; acrylamide; N-methylolacrylamide; N-(C 1 to C 22 )alkyl acrylamide, N,N-di-(C 1 to C 22 )alkyl acrylamide, hydroxy alkyl(meth)acrylamide, N-vinylformamide; N-(C 1 to C 22 )alkyl-N-vinylformamide, N-vinylacetamide, N-(C 1 to C 22 )alkyl-N-vinylacetamide, N-vinyl propionamide, N-(C 1 to C 22 )alkyl-N-vinyl propionamide, (meth)acrylic acid; the esters, nitriles, and amides of (meth)acrylic acid; vinyl acetate, vinyl propionate, vinyl alcohol, (C 1 to C 22 )alkyl vinyl ethers, vinylpyrrolidone; polyetheramine; and copolymers thereof.

11. A process according to claim 7 , wherein the B mer is N-vinylformamide, and the primary amine-containing polymer is a poly(vinylamine-co-vinylformamide) copolymer, or a salt thereof.

12. A process according to claim 7 , wherein the B mer is N-vinylacetamide and the primary amine containing polymer is a poly(vinylamine-co-vinylacetamide), or a salt thereof.

13. A process according to claim 7 , wherein the primary amine-containing polymer includes at least two B mer units.

14. A process according to claim 13 , wherein the primary amine-containing polymer is a poly(vinylamine-co-vinylformamide-co-diallyldimethylammonium chloride) terpolymer, or a salt thereof.

15. A process according to claim 13 , wherein said B mer units are N-(C 6 to C 22 )alkyl acrylamide and vinylformamide.

16. A process according to claim 15 , wherein the primary amine-containing polymer is a poly(vinylamine-co-vinylformamide-co-N-t-octylacrylamide) terpolymer, or a salt thereof.

17. A process according to claim 1 , wherein the primary amine-containing polymer is branched.

18. A process according to claim 1 , wherein the weight average molecular weight of the primary amine-containing polymer is from 300 Daltons to 300,000 Daltons.

19. A process according to claim 1 , wherein the percentage of primary amine in the polymer is from 45 mole % to 100 mole % based on the total percentage of mer units in the polymer.

20. A process according to claim 19 , wherein the percentage of primary amine in the polymer is from 55 mole % to 100 mole % based on the total percentage of mer units in the polymer.

21. A process according to claim 7 , wherein the percentage of primary amine in the polymer is from 45 mole % to 99 mole % based on the total percentage of mer units in the polymer.

22. A process according to claim 21 , wherein the ratio of primary amine in the polymer is from 60 mole % to 99 mole %.

23. A process according to claim 1 , wherein the scale produced contains at least one species of scale-forming ion selected from the group consisting of Na 2 SiF 6 ; K 2 SiF 6 ; CaSO 4 +2 H 2 O; CaSO 4 +½ H 2 O; CaSO 4 ; MgSiF 6 +6 H 2 O; Ca 3 (PO 4 ) 2 ; CaHPO 4 ; Si 2 F 6 ; CaSiF 6 +2 H 2 O; CaF 2 ; MgF 2 ; Mg 0.8 Al 1.5 F 6 +X H 2 O, wherein X is an integer ranging from 2 to 10; MgH 2 P 6 O 7 ; Al(PO 3 ) 3 ; NaK 2 AlF 6 ; Ca 3 (AlF 6 ) 2 +4 H 2 O; MgNaAlF 6 +2 H 2 O; and Ca 4 SO 4 AlSiF 13 +10 H 2 O.

24. A process according to claim 1 , wherein the reagent is added to any of the interstitial piping of the phosphoric acid production plant and/or to one or more stages of the phosphoric acid production process selected from the group consisting of the milling stage; the digesting stage; the filtering stage; the evaporation stage; and the clarifying stage.

25. A process according to claim 1 , wherein the scale-inhibiting amount of reagent added to the wet process phosphoric acid production process is from 0.5 g per ton to 5000 g per ton of phosphoric acid.

Assignees

• Cytec Ind Inc

Inventors

• Zhang Lei
• Carr John
• Chen Haunn Lin Tony

Classifications

• C01B25/235 Primary

  Clarification; Stabilisation to prevent post-precipitation of dissolved impurities · CPC title

• C23F14/02

  by chemical means · CPC title

• C01B25/22 Primary

  Preparation by reacting phosphate-containing material with an acid, e.g. wet process · CPC title

• C08F26/04

  Diallylamine · CPC title

• C02F5/12

  containing nitrogen (C02F5/14 takes precedence) · CPC title