COMPOSITION AND METHOD FOR INHIBITING THE FORMATION AND GROWITH OF POPCORN POLYMERS

Abstract

A method of minimizing popcorn polymer seed formation, the method adding a treatment composition to a monomer containing system. A method for inhibiting popcorn polymer growth, the method adding a treatment composition to a monomer containing system, wherein the treatment composition comprises a quinone methide, a quinone methide derivative, or a quinone methide analogue based compound, and wherein the system comprises popcorn seed or polymer.

Claims

1. A method of minimizing popcorn polymer seed formation, the method comprising: adding a treatment composition to a monomer containing system, said system being capable of forming popcorn polymer seed or comprises popcorn polymer seeds.

2. The method according to claim 1, wherein said monomer containing system comprises an olefin monomer production system, a monomer recovery process, or a monomer production process.

3. The method according to claim 1, wherein said system comprises styrene, vinyl acetate, acrylic acid, isoprene, 1,3-butadiene, or chloroprene.

4. The method according to claim 1, wherein said treatment composition comprises a quinone methide based compound.

5. The method according to claim 4, wherein said quinone methide based compound comprises a quinone methide oligomer, a quinone methide polymer, or quinone methide derivative.

6. The method according to claim 5, wherein said quinone methide based compound is a quinone methide derivative having the formula (I) ##STR00005## wherein R1 and R2 are independently H, C4 to C18 alkyl; C5 to C12 cycloaklyl; or C7 to C15 phenylalkyl; and R3 is aryl, or aryl substituted with C1 to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy, or mixtures thereof.

7. The method according to claim 5, wherein said quinone methide based compound comprises 4,4-(Phenylmethylene)bis[2,6-bis(2-methyl-2-propanyl)phenol] or 4,4-(Phenylmethoxy)bis[2,6-di-tert-butyl)phenol].

8. The method according to claim 5, wherein said quinone methide based compound comprises 2,6-ditert-butyl-4-((3,5-di-tert-butyl-4-hydroxy-benzylidene)-cyclohexa-2,5-dienone, or 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dienone.

9. The method according to claim 5, wherein said quinone methide derivative comprises 4,4-Methylenebis(2,6-di-tert-butylphenol), 2,2-Methylenebis(6-tert-butyl-4-ethylphenol), 2,2-Methylenebis(4-methyl-6-tert-butylphenol), or 1,3,5-Trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

10. The method according to claim 4, wherein said treatment composition further comprises an antioxidant, an anti-polymerant, a metal chelant, and/or an oxygen scavenger.

11. The method according to claim 10, wherein said treatment composition comprises an antioxidant or an anti-polymerant, and wherein said antioxidant or anti-polymerant comprises amino phenols, amino cresols, phenylene diamine compounds, butylated hydroxytoluene, cresylic acid, butylated hydroxyanisole, p-cresol, p-methoxyphenol, dimethylphenols, propyl gallate, p-(p-methoxybenzylidene)amino)phenol, 2,2-Ethylidenebis(4,6-di-tert-butylphenol), (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl, dialkyl thiodipropinates, aryl and alkylphosphites, metal salts of dithioacids, hydroquinones, or combinations thereof.

12. The method according to claim 10, wherein said metal chelant comprises alkyphenol-formaldehyde-amine adducts, N,N-disalieylidene-1,2-propanediamine, 2,2-methylidene-bis(2,6-di t-butyl-cresol), and combinations thereof.

13. The method according to claim 10, wherein said oxygen scavenger comprises diethylhydroxylamine, hydroxypropyl hydroxylamine, catalyzed hydroxylamines, and combinations thereof.

14. The method according to claim 13, wherein said catalyzed hydroxylamines comprise a combination of hydroquinone with (i) diethylhydroxylamine and/or (ii) hydroxypropyl hydroxylamine.

15. A method for inhibiting popcorn polymer growth, the method comprising: adding a treatment composition to a monomer containing system, wherein said treatment composition comprises a quinone methide, a quinone methide derivative, or a quinone methide analogue based compound, and wherein said system comprises popcorn seed or polymer.

16. The method according to claim 15, wherein said monomer containing system comprises an olefin monomer production system, a monomer recovery process, or a monomer production process.

17. The method according to claim 15, wherein said system comprises styrene, vinyl acetate, acrylic acid, isoprene, 1,3-butadiene, or chloroprene.

18. The method according to claim 15, wherein said treatment composition comprises a quinone methide based compound, said quinone methide based compound comprising a quinone methide oligomer, a quinone methide polymer, or quinone methide derivative.

19. The method according to claim 18, wherein said quinone methide based compound is a quinone methide derivative having the formula (I) ##STR00006## wherein R.sub.1 and R.sub.2 are independently H, C4 to C18 alkyl; C5 to C12 cycloaklyl; or C7 to C15 phenylalkyl; and R.sub.3 is aryl, or aryl substituted with C1 to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy, or mixtures thereof.

20. The method according to claim 18, wherein said quinone methide based compound comprises 2,6-ditert-butyl-4-((3,5-di-tert-butyl-4-hydroxy-benzylidene)-cyclohexa-2,5-dienone, 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dienone.

21. The method according to claim 18, wherein said quinone methide based compound comprises 4,4-(Phenylmethylene)bis[2,6-bis(2-methyl-2-propanyl)phenol] or 4,4-(Phenylmethoxy)bis[2,6-di-tert-butyl)phenol].

22. The method according to claim 18, wherein said quinone methide derivative comprises 4,4-Methylenebis(2,6-di-tert-butylphenol), 2,2-Methylenebis(6-tert-butyl-4-ethylphenol), 2,2-Methylenebis(4-methyl-6-tert-butylphenol), or 1,3,5-Trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

23. The method according to claim 15, wherein said treatment composition further comprises an antioxidant, an anti-polymerant, a metal chelant, and/or an oxygen scavenger.

24. The method according to claim 23, wherein said treatment composition comprises an antioxidant or an anti-polymerant, wherein said antioxidant or anti-polymerant comprises amino phenols, amino cresols, phenylene diamine compounds, butylated hydroxytoluene, cresylic acid, butylated hydroxyanisole, p-cresol, p-methoxyphenol, dimethylphenol s, propyl gallate, p-(p-methoxybenzylidene)amino)phenol, 2,2-Ethylidenebis(4,6-di-tert-butylphenol), (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl, dialkyl thiodipropinates, aryl and alkylphosphites, metal salts of dithioacids, hydroquinones, or combinations thereof.

25. The method according to claim 23, wherein said treatment composition comprises a metal chelant, wherein said metal chelant comprises alkyphenol-formaldehyde-amine adducts, N,N-disalieylidene-1,2-propanediamine, 2,2-methylidene-bis(2,6-di t-butyl-cresol), or combinations thereof.

26. The method according to claim 23, wherein said treatment composition comprises an oxygen scavenger, wherein said oxygen scavenger comprises diethylhydroxylamine, hydroxypropyl hydroxylamine, catalyzed hydroxylamines, or combinations thereof.

27. The method according to claim 26, wherein said catalyzed hydroxylamines comprise a combination of hydroquinone with (i) diethylhydroxylamine and/or (ii) hydroxypropyl hydroxylamine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and other features of the disclosed technology, and the advantages, are illustrated specifically in embodiments now to be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

[0029] FIG. 1 is a graph providing results of an illustrative embodiment of the disclosed technology; and

[0030] FIG. 2 is a graph providing results of an illustrative embodiment of the disclosed technology.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0031] The disclosed technology provides for a treatment composition and method to inhibit the formation and growth of popcorn polymers, and more specifically, a treatment composition and method of minimizing popcorn polymer seed formation and inhibiting popcorn polymer growth. As used herein the terms popcorn and popcorn polymer are used interchangeably and refer to a specific type of porous crosslinked polymer which is proliferous, active, or pyrophoric in nature.

[0032] As previously explained, popcorn polymers can occur in either liquid phase or gaseous phase. Higher monomer concentration is more likely to form popcorn polymers, and where iron rust, oxygen (in presence of iron), or humidity are known initiators for popcorn polymerization. Popcorn polymer formation is basically consisted of two stages. The first stage is popcorn seed formation through a series of transformation steps. The second stage is rapid seed growth into large lumps of popcorn polymer in presence of monomer in a self-accelerated propagation rate, where the seeds will propagate until all monomer is consumed. The growth rate of popcorn polymer increases with time exponentially because new free radical actives sites or seeds are formed due to fracture of popcorn polymer caused by internal stress during growth. Also, termination rate is very low because the active free radicals are sterically immobilized. Because of this reason, the free radicals inside the popcorns have a long life.

[0033] In a first embodiment of the disclosed technology, a method of minimizing popcorn polymer seed formation is provided. The method comprises adding a treatment composition to a monomer containing system. The monomer containing system is capable of forming popcorn polymer seeds, or comprises popcorn polymer seeds. In such embodiments, the method prevents popcorn polymer formation by inhibiting or minimizing the formation of popcorn seeds.

[0034] In some embodiments, the treatment composition is added to an upstream portion of the monomer containing system, such as an ethylene production plant. In such embodiments, the treatment composition is added to all or a portion of a hydrocarbon stream entering/within the condensate stripper/gasoline stripper unit of an ethylene production unit. In some embodiments, the treatment composition is added to all or a portion of a hydrocarbon stream entering/within the charge gas compressor of an ethylene production unit. In some embodiments, the treatment composition is added to all or a portion of a hydrocarbon stream entering or within the ethylene fractionation/purification train (e.g. deethanizer, depropanizer, debutanizer towers and the interconnected series of exchangers, towers, reboilers, etc.).

[0035] The treatment composition comprises a quinone methide based compound. In some embodiments, the quinone methide (QM) based compound comprises a quinone methide oligomer, a quinone methide polymer, or quinone methide derivative. As described herein, quinone methide (QM) and its derivatives can prevent popcorn polymer formation by inhibiting the popcorn seeds formation or growth

[0036] In some embodiments, the quinone methide based compound is a quinone methide derivative having the formula (I)

##STR00003##

wherein R1 and R2 are independently H, C4 to C18 alkyl; C5 to C12 cycloaklyl; or C7 to C15 phenylalkyl; and R3 is aryl, or aryl substituted with C1 to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy, or mixtures thereof.

[0037] In some embodiments, the quinone methide based compound comprises 4,4-(Phenylmethylene)bis[2,6-bis(2-methyl-2-propanyl)phenol], and/or 4,4-(Phenylmethoxy)bis[2,6-di-tert-butyl)phenol].

[0038] In some embodiments, the quinone methide based compound comprises 2,6-ditert-butyl-4-((3,5-di-tert-butyl-4-hydroxy-benzylidene)-cyclohexa-2,5-dienone, and/or 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dienone.

[0039] In some embodiments, the quinone methide derivative comprises 4,4-Methylenebis(2,6-di-tert-butylphenol), 2,2-Methylenebis(6-tert-butyl-4-ethylphenol), 2,2-Methylenebis(4-methyl-6-tert-butylphenol), and/or 1,3,5-Trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0040] In some embodiments, the treatment composition further comprises an antioxidant or an anti-polymerant. It is believed that the presence of the antioxidant or an anti-polymerant as described herein minimizes popcorn seed formation, as well as popcorn seed growth.

[0041] In such embodiments, the antioxidant or anti-polymerant comprises amino phenols, amino cresols, phenylene diamine compounds, butylated hydroxytoluene, cresylic acid, butylated hydroxyanisole, p-cresol, p-methoxyphenol, dimethylphenols, propyl gallate, p-(p-methoxybenzylidene)amino)phenol, 2,2-Ethylidenebis(4,6-di-tert-butylphenol), (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl, dialkyl thiodipropinates, aryl and alkylphosphites, metal salts of dithioacids, hydroquinones, and/or combinations thereof.

[0042] In some embodiments, the treatment composition further comprises a metal chelant. It is believed that the presence of a metal chelant is useful in minimizing popcorn seed formation. In such embodiments, the metal chelant comprises alkyphenol-formaldehyde-amine adducts, N,N-disalieylidene-1,2-propanediamine, 2,2-methylidene-bis(2,6-di t-butyl-cresol), and/or combinations thereof.

[0043] In some embodiments, the treatment composition further comprises an oxygen scavenger. It is believed that the presence of oxygen scavengers is useful in minimizing popcorn seed formation. In such embodiments, the oxygen scavenger comprises diethylhydroxylamine, hydroxypropyl hydroxylamine, catalyzed hydroxylamines, and/or combinations thereof. In some embodiments, the catalyzed hydroxylamines comprise a combination of hydroquinone with (i) diethylhydroxylamine, and/or (ii) hydroxypropyl hydroxylamine.

[0044] In some embodiments, the scavenger composition is added to a downstream portion of the monomer containing system. In some embodiments, the scavenger composition is added to all or a portion of a hydrocarbon stream entering or within the butadiene extractive distillation unit. In some embodiments, the scavenger composition is added to all or a portion of a hydrocarbon stream entering or within a styrene-butadiene rubber production process.

[0045] In yet another embodiment of the disclosed technology, a method for inhibiting popcorn polymer growth is provided. The method provides for adding a treatment composition to a monomer containing system that comprises popcorn seed or polymer which is capable of further growing into larger popcorn polymer. The monomer containing system comprises a quinone methide, a quinone methide derivative, or a quinone methide analogue based compound.

[0046] In some embodiments, the monomer containing system as described herein comprises an olefin monomer production system, a monomer recovery process, or a monomer production process. In some embodiments, the monomer containing system comprises styrene, vinyl acetate, acrylic acid, isoprene, 1,3-butadiene, and/or chloroprene.

[0047] In some embodiments, the quinone methide based compound comprises a quinone methide oligomer, a quinone methide polymer, or quinone methide derivative. It is believed that the disclosed quinone methide based compounds as described herein scavenge the free radicals existing in the popcorn seeds or polymers to deactivate active growth sites, thereby inhibiting popcorn propagations. In some embodiments, the method provides for about 0.1 ppm to about 10,000 ppm (1%) of quinone methide compound in monomer. In some embodiments, the method provides for about 0.1 ppm to about 100,000 ppm (10%) of quinone methide compound in monomer.

[0048] In some embodiments, the quinone methide based compound is a quinone methide derivative having the formula (I)

##STR00004##

wherein R.sub.1 and R.sub.2 are independently H, C4 to C18 alkyl; C5 to C12 cycloaklyl; or C7 to C15 phenylalkyl; and R.sub.3 is aryl, or aryl substituted with C1 to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy, or mixtures thereof.

[0049] In some embodiments, the quinone methide based compound comprises 2,6-ditert-butyl-4-((3,5-di-tert-butyl-4-hydroxy-benzylidene)-cyclohexa-2,5-dienone, and/or 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dienone.

[0050] In some embodiments, the quinone methide based compound comprises 4,4-(Phenylmethylene)bis[2,6-bis(2-methyl-2-propanyl)phenol], and/or 4,4-(Phenylmethoxy)bis[2,6-di-tert-butyl)phenol].

[0051] In some embodiments, the quinone methide derivative comprises 4,4-Methylenebis(2,6-di-tert-butylphenol), 2,2-Methylenebis(6-tert-butyl-4-ethylphenol), 2,2-Methylenebis(4-methyl-6-tert-butylphenol), and/or 1,3,5-Trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0052] The treatment composition further comprises an antioxidant, an anti-polymerant, a metal chelant, and/or an oxygen scavenger.

[0053] In some embodiments, the antioxidant or anti-polymerant comprises amino phenols, amino cresols, phenylene diamine compounds, butylated hydroxytoluene, cresylic acid, butylated hydroxyanisole, p-cresol, p-methoxyphenol, dimethylphenols, propyl gallate, p-(p-methoxybenzylidene)amino)phenol, 2,2-Ethylidenebis(4,6-di-tert-butylphenol), (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl, dialkyl thiodipropinates, aryl and alkylphosphites, metal salts of dithioacids, hydroquinones, and/or combinations thereof.

[0054] In some embodiments, the metal chelant comprises alkyphenol-formaldehyde-amine adducts, N,N-disalieylidene-1,2-propanediamine, 2,2-methylidene-bis(2,6-di t-butyl-cresol), and/or combinations thereof.

[0055] In some embodiments, the oxygen scavenger comprises diethylhydroxylamine, hydroxypropyl hydroxyl amine, catalyzed hydroxyl amines, and/or combinations thereof. In some embodiments, the catalyzed hydroxylamines comprise a combination of hydroquinone with (i) diethylhydroxylamine and/or (ii) hydroxypropyl hydroxylamine.

EXAMPLES

[0056] The present technology will be further described in the following examples, which should be viewed as being illustrative and should not be construed to narrow the scope of the disclosed technology or limit the scope to any particular embodiments.

[0057] Approximately 0.2 g of popcorn seeds received from a chemical plant were added to 10 ml of styrene monomer (inhibitor removed) which was then dosed with 100 ppm inhibitor treatment. The solution was purged using argon for 5 minutes to remove dissolved oxygen, and then placed in an oven at 60? C. to initiate seed growth. Popcorn polymer height was measured and recorded as a function of time. After 45 hours, the popcorn was purified, dried, and then weighed to determine the final polymer amount. Growth rate was calculated according to ln(W.sub.f/W.sub.0) in which W.sub.f is the final popcorn polymer weight and W.sub.0 is the initial seed weight.

[0058] Each test was repeated two times and the average growth rate was calculated. Blank test without any inhibitor treatment was included as control. Different chemical compounds including N,N-Di-sec-butyl-p-phenylenediamine (PDA), 2,6-Di-tert-butyl-4-methylphenol (BHT), N,N-Diethylhydroxylamine (DEHA), Hydroquinone (HQ), 4-Hydroxy-TEMPO (4-OH), and 2,5-Cyclohexadien-1-one,2,6-bis(1,1-dimethylethyl)-4-(phenylmethylene)-(QM) were tested for comparison. The results are summarized in Table 1 below.

TABLE-US-00001 TABLE 1 Popcorn Growth Ave. Growth Growth Popcorn height (mm) weight rate rate rate/hour 4 20 26 45 (final) (45 (45 (Rate Vial Treatment Start hours hours hours hours (g) hours) hours) constant k) 1 Blank 18 18 44 45 45 7.1262 3.54 3.41 0.0758 2 Blank 10 10 42 44 45 5.3116 3.27 3 PDA 13 13 40 43 45 5.5933 3.30 3.37 0.0749 4 PDA 10 10 40 43 45 6.4306 3.44 5 BHT 12 12 45 45 45 7.5058 3.62 3.56 0.0791 6 BHT 12 12 45 45 45 6.6708 3.49 7 DEHA 11 11 13 14 42 2.438 2.50 2.63 0.0584 8 DEHA 15 15 17 18 43 3.1884 2.75 9 HQ 12 12 15 16 35 3.0583 2.72 2.76 0.0613 10 HQ 15 15 20 21 38 3.2626 2.80 11 4-OH 12 12 13 13 41 1.4761 1.97 1.97 0.0438 12 4-OH 12 12 13 13 40 1.4929 1.97 13 QM 13 13 15 15 37 0.4393 0.79 0.56 0.0124 14 QM 12 12 15 15 30 0.2778 0.32

[0059] The growth rate for each chemical compound is compared in FIG. 1. Popcorn height is plotted as function of time in FIG. 2. These results indicate that quinone methide exhibited the best inhibition performance among all the tested compounds. Quinone methide (QM) was very effective in inhibiting popcorn seed propagation, thereby preventing popcorn polymer formation.

[0060] While embodiments of the disclosed technology have been described, it should be understood that the present disclosure is not so limited and modifications may be made without departing from the disclosed technology. The scope of the disclosed technology is defined by the appended claims, and all devices, processes, and methods that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.