EP4638403A1 - Improved fouling control in production of vinyl aromatic monomers with dispersant-based chemical treatment - Google Patents

Abstract

A product and method for reducing fouling of a vinyl aromatic monomer including a first composition comprising an effective amount of one or more dispersants and a second composition comprising an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

Description

IMPROVED FOULING CONTROL IN PRODUCTION OF VINYL AROMATIC MONOMERS WITH DISPERSANT-BASED CHEMICAL TREATMENT

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/433/680, filed on December 19, 2022, which is incorporated by reference herein in its entirety.

FIELD

[0002] The disclosed technology relates to compositions, products and methods for reducing fouling during production of vinyl aromatic monomers, such as styrene monomers, using dispersant chemistries.

BACKGROUND

[0003] In styrene production processes, polymers are generated due to thermal polymerization of styrene and other reactive monomers. The amount of polymer generated depends on temperature, time, any catalysts/contaminants. and any other reactive monomers (e.g. divinylbenzene). The undesired polymer side-product can foul the process equipment and/or piping and cause a number of processing, production, and product quality problems such as product contamination.

[0004] Hence, it is desirable to minimize the amount of fouling to be able to meet production and reliability goals. The conventional approach is to use a combination of at least one true polymerization inhibitor and a polymerization retarder to minimize the amount of polymer produced, and prevent the associated fouling and heat transfer problems. However, due to economic controls on dosage of inhibitors and retarders, a significant amount of polymer may still be formed. Additionally, any significant amount of divinylbenzene (DVB) produced during the dehydrogenation step of the production process or brought into the process through a recycle/import stream can lead to formation of insoluble crosslinked co-polymers. For example, the amount of DVB may increase as the dehydrogenation catalyst degrades over time. [0005] A different approach for fouling control in vinyl aromatic monomer production processes is needed.

SUMMARY

[0006] The disclosed technology provides for controlling fouling of vinyl aromatic monomers, such as styrene monomers, using compositions including one or more dispersants.

[0007] Various aspects of the disclosure relate to a product for controlling fouling of a vinyl aromatic monomer comprising a first composition comprising an effective amount of one or more dispersants, and a second composition comprising an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

[0008] In various aspects, the product comprises a first composition comprising an effective amount of one or more dispersants and a second composition comprising an effective amount of one or more polymerization inhibitors.

[0009] In various aspects, the product comprises a first composition comprising an effective amount of one or more dispersants and a second composition comprising an effective amount of one or more polymerization retarders.

[0010] In various aspects, the product comprises a first composition comprising an effective amount of one or more dispersants, a second composition comprising an effective amount of one or more polymerization inhibitors, and a third composition comprising an effective amount of one or more polymerization retarders.

[0011] Various aspects of the disclosure additionally relate to a method of controlling fouling of a vinyl aromatic monomer comprising adding to the monomer a first composition comprising an effective amount of one or more dispersants.

[0012] In various aspects of the disclosed method, the method further comprises adding to the monomer a second composition comprising an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

[0013] In various aspects of the disclosed method, the method comprises adding to the monomer a first composition comprising an effective amount of one or more dispersants, adding to the monomer a second composition comprising an effective amount of one or more polymerization inhibitors, and adding to the monomer a third composition comprising an effective of one or more polymerization retarders.

BRIEF DESCRIPTION OF THE FIGURES

[0014] Those of skill in the art will understand that the figures, described below, are for illustrative purposes only. The figures are not intended to limit the scope of the present teachings in any way.

[0015] FIG. 1A illustrates the settling index for a polymeric mixture containing poly(styrene-co-divinylbenzene) untreated with a dispersant;

[0016] FIGS. 1B-1D shows a graphical representation of the settling index for various mixtures of the disclosed technology, wherein the mixtures contain polyfstyrene- co-divinylbenzene) treated with different dispersants.

[0017] FIG. 2A illustrates the viscosity of untreated styrene samples polymerized with DVB as compared to the viscosity of the same styrene samples treated with an example embodiment of the dispersant of the disclosure.

[0018] FIG. 2B illustrates the viscosity of untreated styrene samples polymerized with DVB as compared to the viscosity of the same styrene samples treated with two example embodiments of dispersants of the disclosure one day after polymerization.

[0019] FIG. 3 illustrates the viscosity of the viscosity of untreated sty rene samples polymerized with DVB as compared to the viscosity of the same styrene samples treated with two example embodiments of dispersants of the disclosure four days after polymerization.

DETAILED DESCRIPTION

[0020] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “abouf ’, is not limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Range limitations may be combined and/or interchanged, and such ranges are identified and include all the sub-ranges stated herein unless context or language indicates otherwise. Other than in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions and the like, used in the specification and the claims, are to be understood as modified in all instances by the term 'about".

[0021] ‘'Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, or that the subsequently identified material may or may not be present, and that the description includes instances where the event or circumstance occurs or where the material is present, and instances where the event or circumstance does not occur or the material is not present.

[0022] As used herein, the terms '‘comprises”, “comprising”, “includes”, “including”, “has”, “having”, or any other variation thereof, are intended to cover a nonexclusive inclusion. For example, a process, method, article or apparatus that comprises a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0023] The singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0024] The disclosed technology provides for products and methods for reducing fouling of vinyl aromatic monomers, such as styrene monomers, using compositions comprising one or more dispersants.

[0025] The products and methods disclosed herein have been found to be effective in maintaining undesirable polymers in styrene production processes, for example, insoluble crosslinked divinylbenzene-styrene copolymers, in a dispersed state. This leads to lower overall viscosity and lower deposit tendency in the styrene production process.

[0026] As used herein, the term “dispersant” refers to a component capable of enhancing the dispersibility of polymers generated due to thermal polymerization of vinyl aromatic monomers.

[0027] As used herein, the term “polymerization inhibitor” refers to chemical compounds added to monomers, such as vinyl aromatic monomers, to prevent their autopolymerization.

[0028] As used herein, the term “polymerization retarder’ refers to molecules that reduce the rate of polymerization of monomers such as vinyl aromatic monomers. [0029] As used herein, the term “an effective amount” refers to any amount of a dispersant, polymerization inhibitor and/or polymerization retarder that is effective in inhibiting polymerization of a vinyl aromatic monomer.

[0030] In various aspects of the disclosed technology, a product for controlling fouling of a vinyl aromatic monomer is disclosed. In various aspects, the product may include a first composition including an effective amount of one or more dispersants. The product may also include a second composition including an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

[0031] In some aspects, the product may include a first composition including an effective amount of one or more dispersants and a second composition including an effective amount of one or more polymerization inhibitors. In other aspects, the product may include a first composition including an effective amount of one or more dispersants and a second composition including an effective amount of one or more polymerization retarders. In some aspects, the product may include a first composition including an effective amount of one or more dispersants, a second composition including an effective amount of one or more polymerization inhibitors, and a third composition including an effective amount of one or more polymerization retarders.

[0032] In various aspects, suitable dispersants may include any component capable of enhancing the dispersibility of polymers generated due to thermal polymerization of vinyl aromatic monomers. In some aspects, suitable dispersants may include any component capable of enhancing the dispersibility of polymers generated due to thermal polymerization of styrene and other reactive monomers. In various aspects, suitable dispersants may include alkenyl succinic acids; alkenyl succinic acid reaction products with polyamines; alkenyl succinic acid reaction products with polyhydric alcohols; alkenyl thiophosphonic acid reaction products with polyhydric alcohols; alkenyl phosphonate, alkenyl esters; metal salts of alkylphenol sulfide; metal salts of alkyd sulfonate; metal salts of aryl sulfonate; metal salts of alkyl salicylate; reaction products of fatty acids and polyamine; reaction products of fatty' acids, formaldehyde and polyamine; reaction products of fatty acid and hydroxylated amine; reaction products of alkylphenol, formaldehyde and polyamine; reaction products of maleic anhydride, alkenyl hydrocarbons, and polyamines; reaction products of maleic anhydride, alkenyl hydrocarbons, polyamines, and aryl anhydride; reaction products of aryl anhydride, alkenyl hydrocarbons, and polyamines; glycolipids; derivatives thereof; or mixtures thereof.

[0033] In various aspects, the dispersant may be present in an amount of between about 1 ppm to about 5000 ppm, or about 1, 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100. 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, or 5000 ppm, or about 1 ppm to about 1000 ppm or about 1 ppm to about 500 ppm, or about 10 ppm to about 100 ppm or about 100 ppm to about 1000 ppm or about 1 ppm to about 100 ppm or about 100 ppm to about 500 ppm, or any amount between any of these values.

[0034] In various aspects, suitable polymerization inhibitors may include any compound added to monomers, such as vinyl aromatic monomers, that prevent their autopolymerization. In some aspects, suitable polymerization inhibitors may include hydroxylamine derivatives. Suitable hydroxylamine derivatives include hydroxylamines having the functional group — NOH — and the general formula Rl-NOH — R2. R1 and R2 may be the same or different and are hydrogen, alkyl, aryl, alkaryl, or hydroxyalkyl groups and may have three to about twenty carbon atoms. In some aspects, suitable hydroxylamine derivatives include 2-propanol, l,l'-(hydroxyimino)bis, 1,1'- (hydroxyimino)dipropan-2-ol, or bis l,l-(2-Propanol)-hydroxyimine. In various aspects, suitable polymerization inhibitors may further include phenolic containing inhibitors, such as 4-tert-butylcatechol. butylated hydroxy toluene, 2,6-ditertbutylphenol, and combinations thereof.

[0035] In various aspects, the polymerization inhibitors may be formulated with a stable free radical. Suitable stable free radicals may include nitroxyl compounds, such as 4-hydroxy-2,2,6,6-tetramethyl-l-piperidinyloxy. or tetramethylpiperidino-N-oxyl, or 1- oxyl-2,2,6,6-tetramethyl-4-piperidinol. or the like.

[0036] In various aspects, suitable polymerization retarders may include any molecule that reduces the rate of polymerization of monomers, such as vinyl aromatic monomers. In various aspects, suitable polymerization retarders may include dinitro phenolic compounds, including 2,6-dinitro-p-cresol, 2,4-dinitrophenol. 2.4-dinitro-o- cresol, and 2,4-dinitro-6-sec-butylphenol and quinone methide. The quinone methide (QM) compound has the formula:

[0037] wherein R3 and R4 are independently H, Cl to C18 alkyl, C5 to C12 cycloalkyl; or C7 to C15 phenylalkyl, and R5 is aryl, or aryl substituted with Cl to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy or mixtures thereof.

[0038] In various aspects, the polymerization inhibitors and polymerization retarders are included in any amount that is sufficient to inhibit polymerization of vinyl aromatic monomers. In some aspects of the method, concentrations of polymerization retarders may range from about 500 to about 1500 ppm or about 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400 or 1500 ppm, or any amount in between any of these values. In various aspects of the method, concentrations of polymerization inhibitors may range from about 50 to about 500 ppm, or about 50, 60, 70, 80, 90, 100, 200. 300, 400 or 500 ppm, or any amount in between any of these values. These amounts may vary according to the conditions under which the vinyl aromatic monomer is being processed, contaminants in the system, and the temperature of the system. At higher processing temperatures and higher monomer contamination, larger amounts of polymerization inhibitors and polymerization retarders may be required.

[0039] In various aspects, the first composition, second composition and/or third composition include a liquid carrier. Suitable liquid carriers may include water, non-polar organic solvents, and combinations thereof. In some aspects, suitable liquid carriers may include toluene, ethyl benzene, aromatic solvent, or the like.

[0040] In various aspects, the product of the disclosed technology may be used in a method of inhibiting the polymerization of vinyl aromatic monomers. In various aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more dispersants. In some aspects, the method may further include adding to the monomer a second composition including an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

[0041] In some aspects of the method, the second composition may include an effective amount of one or more polymerization inhibitors. In other aspects, the second composition may include an effective amount of one or more polymerization retarders.

[0042] In various aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more dispersants; adding to the monomer a second composition comprising an effective amount of one or more polymerization inhibitors; and further adding to the monomer a third composition including an effective amount of one or more polymerization retarders.

[0043] In various aspects of the method, suitable dispersants may include any component capable of enhancing the dispersibility of polymers generated due to thermal polymerization of vinyl aromatic monomers. In various aspects, suitable dispersants may include alkenyl succinic acids; alkenyl succinic acid reaction products with polyamines; alkenyl succinic acid reaction products with polyhydric alcohols; alkenyl thiophosphonic acid reaction products with polyhydric alcohols; alkenyl phosphonate, alkenyl esters; metal salts of alkylphenol sulfide; metal salts of alkyl sulfonate; metal salts of aryl sulfonate; metal salts of alkyl salicylate; reaction products of fatty acids and polyamine; reaction products of fatty⁷ acids, formaldehyde and polyamine; reaction products of fatty acid and hydroxylated amine; reaction products of alkylphenol, formaldehyde and polyamine; reaction products of maleic anhydride, alkenyl hydrocarbons, and polyamines; reaction products of maleic anhydride, alkenyl hydrocarbons, polyamines, and aryl anhydride; reaction products of aryl anhydride, alkenyl hydrocarbons, and polyamines; glycolipids; derivatives thereof; or mixtures thereof.

[0044] In various aspects of the method, the dispersant may be added in an amount of between about 1 ppm to about 5000 ppm, or about 1, 10, 50, 100, 200. 300, 400, 500. 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800. 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900. or 5000 ppm, or about 1 ppm to about 1000 ppm or about 1 ppm to about 500 ppm. or about 10 ppm to about 100 ppm or about 100 ppm to about 1000 ppm or about 1 ppm to about 100 ppm or about 100 ppm to about 500 ppm, or any amount between any of these values.

[0045] In various aspects of the method, suitable poly merization inhibitors may include any compound added to monomers, such as vinyl aromatic monomers, that prevent their auto-polymerization. In some aspects, suitable polymerization inhibitors may include hydroxylamine derivatives. Suitable hydroxylamine derivatives include hydroxyl amines having the functional group — NOH — and the general formula Rl- NOH — R2. R1 and R2 may be the same or different and are hydrogen, alkyl, aryl, alkaryl, or hydroxyalkyl groups and may have three to about twenty carbon atoms. In some aspects, suitable hydroxylamine derivatives include 2-propanol, l,l'-(hydroxyimino)bis, l,l'-(hydroxyimino)dipropan-2-ol, or bis l,l-(2-Propanol)-hydroxyimine. In various aspects, suitable polymerization inhibitors may further include phenolic containing inhibitors, such as 4-tert-butylcatechol, butylated hydroxy toluene, 2,6-ditertbutylphenol. and combinations thereof.

[0046] In various aspects, the method may further include addition of a stable free radical. Suitable stable free radicals may include nitroxyl compounds, such as 4-hydroxy- 2,2,6,6-tetramethyl-l-piperidinyloxy, or tetramethylpiperidino-N-oxyl. or 1 -oxyl-2, 2,6,6- tetramethyl-4-piperidinol, or the like.

[0047] In various aspects of the method, suitable polymerization retarders may include any molecule that reduces the rate of polymerization of monomers, such as vinyl aromatic monomers. In various aspects, suitable polymerization retarders may include dinitro phenolic compounds, including 2,6-dinitro-p-cresol. 2,4-dinitrophenol, 2.4-dinitro- o-cresol, and 2,4-dinitro-6-sec-butylphenol and quinone methide. The quinone methide (QM) compound has the formula: [0048] wherein R3 and R4 are independently H, C l to C18 alkyl, C5 to C12 cycloalkyl; or C7 to C15 phenylalkyl, and R5 is aryl, or aryl substituted with Cl to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy or mixtures thereof.

[0049] In various aspects of the method, the polymerization inhibitors and polymerization retarders may be added in any amount that is sufficient to inhibit polymerization of vinyl aromatic monomers. In some aspects of the method, concentrations of polymerization retarders may range from about 500 to about 1500 ppm or about 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300. 1400 or 1500 ppm, or any amount in between any of these values. In various aspects of the method, concentrations of polymerization inhibitors may range from about 50 to about 500 ppm, or about 50, 60, 70, 80, 90, 100, 200, 300, 400 or 500 ppm, or any amount in between any of these values. These amounts may vary according to the conditions under which the vinyl aromatic monomer is being processed, contaminants in the system, and the temperature of the system.

[0050] In various aspects of the method, the first composition, second composition and/or third composition may include a liquid carrier. Suitable liquid carriers may include water, non-polar organic solvents, and combinations thereof. In some aspects, suitable liquid carriers may include toluene, ethyl benzene, aromatic solvent, or the like.

[0051] In various aspects, the method may include inhibiting polymerization of any vinyl aromatic monomer, including styrene, bromostyrene, divinylbenzene and a- methylstyrene monomers, and combinations thereof.

EXAMPLES

[0052] The present technology⁷ 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.

[0053] Example 1

[0054] Tests for screening dispersant chemistries were conducted using mixtures of crosslinked poly(styrene-co-divinylbenzene), hydrocarbon solvent, such as toluene, and various dispersants.

[0055] Untreated Mixture [0056] A mixture containing 10 mg poly (sty rene-co-divinylbenzene), 6-10 pm, 2% crosslinked, and 25 ml of toluene was prepared in a Turbiscan glass vial at room temperature.

[0057] Experimental Mixture 1

[0058] A mixture containing 10 mg poly(styrene-co-divinylbenzene), 6-10 pm, 2% crosslinked, 25 ml of toluene and 5000 ppm of a polyisobutylene succinimide (Producer 1), or PIBSI, was prepared at room temperature.

[0059] Experimental Mixture 2

[0060] A mixture containing 10 mg poly (sty rene-co-divinylbenzene). 6-10 pm. 2% crosslinked, 25 ml of toluene and 5000 ppm of a poly isobutylene succinimide (Producer 2) was prepared at room temperature.

[0061] Experimental Mixture 3

[0062] A mixture containing 10 mg poly (sty rene-co-divinylbenzene), 6-10 pm. 2% crosslinked, 25 ml of toluene and 5000 ppm of a poly isobutylene succinimide (Producer 3) was prepared at room temperature.

[0063] Test of Settling Time and Measurement of Dispersant Efficacy

[0064] The Untreated Mixture and Experimental Mixtures 1-3 were subjected to hand-shaking in order to disperse the poly(styrene-co-divinylbenzene) polymer. Shaking times and strokes were kept consistent for all samples. After dispersion, the vials were left standing to allow the polymer to settle. The Untreated Mixture was subjected to three different experiments.

[0065] The time of complete settling of the polymer to the bottom of the vial for each mixture was monitored and recorded. Turbidity and transmission measurements were obtained using a Turbiscan procedure in order to determine a settling index for each mixture. The settling index was calculated by finding the standard deviation between each average transmission value between tube heights of 30 mm and 40 mm, for 16 scans of each mixture conducted for a period of 15 minutes.

[0066] The settling index for each mixture is shown in Table 1 below:

[0067] Table 1

[0068] As shown in FIGS. 1A-1D. the Untreated Mixture exhibited a percent transmittance between tube heights of 30 mm and 40 mm that far exceeded that of Experimental Mixtures 1-3, indicating that Experimental Mixtures 1-3 were substantially more effective in inhibiting polymerization when directly compared to an untreated control.

[0069] Example 2

[0070] Rheology Experiment 1

[0071] Styrene was polymerized at 120°C for 1 hour with 100 ppm of DVB. The viscosity of an untreated sample was compared to that of a sample treated with 1000 ppmA of reaction products of alkylphenol, formaldehyde and polyamine ([AP + F + PA]); and a sample treated with 1000 ppmA of PIBSI. As shown in FIGS. 2A and 2B, the reaction products of alkylphenol, formaldehyde and polyamine, reduced the viscosity of the samples by about 20% when compared to the untreated samples, even when tested 1 day after preparation. Also as shown in FIG. 2B, PIBSI reduced the viscosity of the sample by about 4.5%.

[0072] Rheology Experiment 2

[0073] Styrene was polymerized at 120°C for 30 minutes with 100 ppm of DVB. The viscosity of an untreated sample was compared to that of a sample treated with 1000 ppmA of reaction products of alkylphenol, formaldehyde and polyamine; and a sample treated with 1000 ppmA of PIBSI. As shown in FIG. 3, the reaction products of alkylphenol, formaldehyde and polyamine, reduced the viscosity of the sample by about 62% when compared to the untreated sample, 4 days after polymerization. Also as shown in FIG. 3. PIBSI reduced the viscosity of the sample by about 20%.

[0074] Example 3

[0075] Styrene was polymerized for 30 minutes. Reaction products of alkylphenol, formaldehyde and polyamine were added to the sample in combination with various amounts of quinone methide (QM), 2,6-Di-tert-butylphenol (2,6-DTBP) and hydroxypropyl hydroxylamine (HPHA). The percent reduction in viscosity (cP) was assessed for each combination at a shear rate of 1 , with results shown in Table 1 below: [0076] Table 1

[0077] As can be seen from Table 1, at a shear rate of 1, the combination of reaction products of alkylphenol, formaldehyde and polyamine, quinone methide (QM), 2.6-Di-tert-butylphenol (2.6-DTBP). and hydroxypropyl hydroxylamine (HPHA) provided a larger reduction in viscosity than the control samples.

[0078] 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.

Claims

1. A product for reducing fouling during the production of a vinyl aromatic monomer comprising: a first composition comprising an effective amount of one or more dispersants; and a second composition comprising an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

2. The product of claim 1 comprising: a first composition comprising an effective amount of one or more dispersants; and a second composition comprising an effective amount of one or more polymerization inhibitors.

3. The product of claim 1 comprising: a first composition comprising an effective amount of one or more dispersants; and a second composition comprising an effective amount of one or more polymerization retarders.

4. The product of claim 1 comprising: a first composition comprising an effective amount of one or more dispersants; a second composition comprising an effective amount of one or more polymerization inhibitors; and a third composition comprising an effective amount of one or more polymerization retarders.

5. The product of claims 1-4, wherein the one or more dispersants is selected from the group consisting of alkenyl succinic acids; alkenyl succinic acid reaction products with polyamines; alkenyl succinic acid reaction products with polyhydric alcohols; alkenyl thiophosphonic acid reaction products with polyhydric alcohols; alkenyl phosphonate, alkenyl esters; metal salts of alkylphenol sulfide; metal salts of alkyd sulfonate; metal salts of aryl sulfonate; metal salts of alkyl salicylate; reaction products of fatty⁷ acids and polyamine; reaction products of fatty acids, formaldehyde and polyamine; reaction products of fatty acid and hydroxylated amine; reaction products of alkylphenol, formaldehyde and polyamine; reaction products of maleic anhydride, alkenyl hydrocarbons, and polyamines; reaction products of maleic anhydride, alkenyl hydrocarbons, polyamines, and aryl anhydride; reaction products of aryl anhydride, alkenyl hydrocarbons, and polyamines; glycolipids; derivatives thereof; or mixtures thereof.

6. The product of claims 1-5, wherein the one or more dispersants is selected from an alkenyl succinic acid reaction product with polyamines.

7. The product of claims 1-5, wherein the one or more dispersants is selected from reaction products of alkylphenol, formaldehyde and polyamine.

8. The product of claim 1, wherein the one or more polymerization inhibitors comprises a hydroxylamine derivative.

9. The product of claim 1, wherein the one or more polymerization retarders is selected from the group consisting of dinitrobutylphenol, quinone methide, and combinations thereof.

10. The product of claims 1-9, wherein the one or more dispersants is present in an amount of between 1 ppm to 5000 ppm.

11. The product of claim 1, wherein the first composition and second composition further comprise a liquid carrier, wherein the liquid carrier is selected from the group consisting of water, non-polar organic solvents, and combinations thereof.

12. The product of claim 11, wherein the liquid carrier comprises toluene, ethyl benzene, or an aromatic solvent.

13. A method of reducing fouling during the production of a vinyl aromatic monomer comprising: adding to the monomer a first composition comprising an effective amount of one or more dispersants.

14. The method of claim 13 further comprising: adding to the monomer a second composition comprising an effective amount of one or more polymerization inhibitors, an effective amount of one or more polymerization retarders, or combinations thereof.

15. The method of claim 14, wherein the second composition comprises an effective amount of one or more polymerization inhibitors.

16. The method of claim 14, wherein the second composition comprises an effective amount of one or more polymerization retarders.

17. The method of claim 13 comprising: adding to the monomer a first composition comprising an effective amount of one or more dispersants; adding to the monomer a second composition comprising an effective amount of one or more polymerization inhibitors; and adding to the monomer a third composition comprising an effective of one or more polymerization retarders.

18. The method of claims 13-17, wherein the one or more dispersants is selected from the group consisting of alkenyl succinic acids; alkenyl succinic acid reaction products vx i th polyamines; alkenyl succinic acid reaction products with polyhydnc alcohols; alkenyl thiophosphonic acid reaction products with polyhydric alcohols; alkenyl phosphonate, alkenyl esters; metal salts of alkydphenol sulfide; metal salts of alky 1 sulfonate; metal salts of aryl sulfonate; metal salts of alky 1 salicylate; reaction products of fatty acids and polyamine; reaction products of fatty acids, formaldehyde and polyamine; reaction products of fatty acid and hydroxylated amine; reaction products of alkylphenol, formaldehyde and polyamine; reaction products of maleic anhydride, alkenyl hydrocarbons, and polyamines; reaction products of maleic anhydride, alkenyl hydrocarbons, polyamines, and and anhydride; reaction products of aryl anhydride, alkenyl hydrocarbons, and polyamines; glycolipids; derivatives thereof; or mixtures thereof.

19. The method of claims 13-18, wherein the one or more dispersants is selected from alkenyl succinic acid reaction products wi th polyamines.

20. The method of claims 13-18, wherein the one or more dispersants is selected from reaction products of alkylphenol, formaldehyde and polyamine.

21. The method of claim 14. wherein the one or more polymerization inhibitors comprises a hydroxylamine.

22. The method of claim 14, wherein the one or more polymerization retarders is selected from the group consisting of dinitrobutylphenol, quinone methide, and combinations thereof.

23. The method of claim 13-22, wherein the one or more dispersants is added in an amount of between 1 ppm to 5000 ppm.

24. The method of claim 13, wherein the first composition further comprises a liquid carrier, wherein the liquid carrier is selected from the group consisting of water, non-polar organic solvents, and combinations thereof.

25. The method of claim 14, wherein the second composition further comprises a liquid carrier, wherein the liquid carrier is selected from the group consisting of water, non-polar organic solvents, and combinations thereof.

26. The method of claims 13-25, wherein the vinyl aromatic monomer is selected from the group consisting of styrene, bromostyrene, divinylbenzene, a-methylstyrene and combinations thereof.