Antipolymerization agent compositions containing naphthoquinone and hydroxylamine and methods of use

Abstract

Compositions and methods for inhibiting and retarding polymerization of monomeric compositions are described that use naphthoquinone and hydroxylamine. When present in a monomer-containing composition, the combination of naphthoquinone and hydroxylamine provides an unexpectedly beneficial anti-polymerization agent effect, inhibiting the formation of unwanted fouling polymers. The anti-polymerization agent combination can be added to a hydrocarbon composition, such as petroleum, that can include a polymerizable component, such as styrene, where the hydrocarbon composition is purified or processed, such as in the case of distillation.

Description

Technical Field

[0001] The present invention relates to compositions and uses of naphthoquinones in combination with hydroxylamines for reducing polymer formation in monomer-containing compositions. Background Art

[0002] Ethylenically unsaturated monomers, such as vinyl aromatic monomers such as styrene, may be present in process streams or refined products made by various chemical industrial processes. However, these monomer types may be undesirably polymerized by free radical polymerization, especially at high temperatures. As a result, solid deposits of polymers are formed on the surface of process equipment during industrial manufacturing, processing, handling or storage. The resulting polymers may be problematic and cause equipment "fouling" and product contamination. Therefore, this may require treatment equipment to remove the polymer, or may require processing steps that require shutdown operations for physical or mechanical removal. Equally important, polymer materials contaminate the processed streams, thereby requiring steps to remove the contaminants from the composition stream or the stored composition. Therefore, these undesirable polymerization reactions lead to a loss of production efficiency because they consume expensive reagents and may require additional steps to clean the equipment and / or remove the undesirable polymers. In compositions with vinyl aromatic monomers, undesirable polymerization reactions are particularly problematic.

[0003] In order to minimize undesired polymerization reactions, compounds that act as anti-polymerization agents are often added to process streams or stored compositions.Two classes of anti-polymerization agents have been developed to minimize unwanted polymerization reactions: polymerization inhibitors and polymerization retarders.

[0004] Polymerization inhibitors inhibit the occurrence of polymerization reactions. However, these compounds are usually consumed quickly. For example, in emergency situations due to mechanical or processing problems, and in cases where it is not possible to add more inhibitor, the previously added inhibitor will be consumed quickly. Subsequently, the unwanted polymerization reaction will then occur rapidly.

[0005] Polymerization retarders slow down the rate of polymerization but are not as effective as polymerization inhibitors. However, polymerization retarders are generally not consumed as quickly as polymerization inhibitors, making them more useful in emergency shutdown operations.

[0006] Retardants such as sulfur and dinitrophenol (DNP) compounds such as 2,6-dinitrophenol, 2,4-dinitrocresol and 2-sec-butyl-4,6-dinitrophenol (DNBP) have been used in anti-aggregation methods. However, DNP and sulfur retardants release NO x and SO x Gases, thus making their use problematic. In addition, DNP-based retarders are highly toxic, which is a concern during handling.

[0007] Another class of compounds designed to be used as safer alternatives to DNP blockers is based on methylated quinone chemistry. Methylated quinones slow the rate of polymer formation under static conditions and do not need to be frequently re-fed into the process stream, but some methylated quinone compounds do not show good stability. Examples of methylated quinone compounds are found in U.S. Patent Nos. 4,003,800, 5,583,247 and 7,045,647.

[0008] Another chemical approach to anti-polymerization technology for high temperature processing of vinyl monomers is 4-hydroxy-2,2,6,6-trimethylolpropane (HTEMPO). Although effective, HTEMPO and its derivatives are effective inhibitors rather than effective retarders.

[0009] Technical challenges regarding polymerization inhibitors and retarders, as well as stability and safety issues, remain in this technical field. In addition, the present disclosure is associated with the discovery that, although it is desirable to combine polymerization inhibitors and retarders in the same composition, the mixtures often suffer from compatibility issues, which reduce the effectiveness of the polymerization inhibitor and retarder activity.

[0010] Recognizing the problems associated with the current state of the art of anti-polymerization agents, the present invention relates to a combination composition that is safer and more effective as an anti-polymerization agent in general and as a retarding agent in particular. Summary of the invention

[0011] Disclosed herein are compositions and methods for reducing polymer formation in compositions that include monomers or that can form monomers. The disclosed methods use naphthoquinones and hydroxylamines as combined anti-polymerization agents that, when used together, exhibit unexpectedly beneficial anti-polymerization effects, such as synergistic anti-polymerization effects. Mixtures of naphthoquinones and hydroxylamines provide excellent activity in inhibiting unwanted polymerization of monomers such as styrene in various applications, such as in synthesis, refining, or storage. By using the naphthoquinone and hydroxylamine combinations of the present invention, polymer contamination can be reduced and additional processing steps can be minimized or avoided. In addition, by acting to inhibit and retard polymerization, the mixture can minimize the accumulation ("fouling") of unwanted polymers on processing or storage equipment, and thus reduce the maintenance costs of such equipment. Moreover, the combination of the present invention allows for a reduction in reagents added to the treated (e.g., hydrocarbon) composition, thereby providing a higher level of refined product purity and reducing the overall cost of the product and the costs associated with its production. In addition, the combination of the present invention can avoid the use of other anti-polymerization compounds that are unsafe, expensive, poorly effective, or a combination thereof.

[0012] Furthermore, in certain embodiments, naphthoquinones and hydroxylamines may be advantageously combined in a single package formulation for addition to a composition that may contain or may form a monomer, wherein the combination exhibits unexpectedly beneficial anti-polymerization effects, such as synergistic anti-polymerization effects, in use.

[0013] In an embodiment, the present disclosure provides a method for inhibiting polymerization of a monomer in a composition containing a monomer. The method includes one or more steps of adding components including naphthoquinone and hydroxylamine to a composition capable of forming a polymerizable monomer. The hydroxylamine has the formula I: HO-NR 1 R 2 , where R 1 and R 2 At least one or both of are carbon-containing groups having 1 to 12 carbon atoms, optionally substituted with one or more hydroxyl groups, wherein if R 1 or R 2 If it is not a carbon-containing group, it is -H; or Formula II:

[0014]

[0015] Where X is -(CHR 5 ) w -, where R 5 Selected from -H, R 3 and R 4 , R 3 is selected from -H and alkyl, and R 4 is selected from -H and -OH, y is 0 or an integer in the range of 1 to 3, z is 0 or an integer in the range of 1 to 3, and w is an integer in the range of 1 to 4. The naphthoquinone and hydroxylamine present in the composition inhibit polymerization of the polymerizable monomers.

[0016] Exemplary naphthoquinones include 1,4-naphthoquinone, 1,3-naphthoquinone, 1,2-naphthoquinone, and derivatives thereof, such as aminated derivatives of naphthoquinone.

[0017] In an exemplary embodiment, the method may include adding the naphthoquinone and hydroxylamine components to a hydrocarbon composition, such as a hydrocarbon composition that is subjected to purification or processing of one or more hydrocarbon components of the composition. The hydrocarbon composition may be derived from a petroleum material and may include a polymerizable component such as styrene, or one or more components that are capable of forming a polymerizable component. For example, the naphthoquinone and hydroxylamine components may be added to a hydrocarbon composition that is subjected to a distillation step, or may be added to a refined composition, prior to storage or transportation.

[0018] In other embodiments, the present disclosure provides an additive composition comprising naphthoquinone, hydroxylamine and a suitable solvent or solvent system. The naphthoquinone and hydroxylamine can be present in the additive composition in a predetermined concentrated amount, so that when the additive composition is added to a composition containing monomers, the concentrated amount is diluted to a working amount that acts in an unexpected (e.g., synergistic) manner to inhibit the polymerization of the monomers. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a graph of polystyrene formation over time in a styrene monomer solution in the presence of 400 ppm of N,N-diethylhydroxylamine (DEHA), 400 ppm of 1,4-naphthoquinone (1,4-NQ), a combination of 200 ppm each of DEHA and 1,4-NQ, and 400 ppm of 2,4-dinitro-6-sec-butylphenol (DNBP).

[0020] Figure 2 is a graph of polystyrene formation over time in a styrene monomer solution in the presence of 400 ppm DEHA, 400 ppm 1,4-NQ, an unexpected (eg, synergistic) combination of 200 ppm each of DEHA and 1,4-NQ, and 400 ppm DNBP.

[0021] Figure 3 is a graph of polystyrene formation over time in a styrene monomer solution in the presence of 400 ppm dibenzylhydroxylamine (DBzHA), 400 ppm 1,4-NQ, an unexpected (eg, synergistic) combination of 200 ppm each of DBzHA and 1,4-NQ, and 400 ppm of DNBP. DETAILED DESCRIPTION

[0022] Although the present disclosure provides references to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the present invention. References to various embodiments do not limit the scope of the claims appended hereto. In addition, any examples set forth in this specification are not intended to limit and only set forth some of the many possible embodiments of the appended claims.

[0023] Additional advantages and novel features of the invention will be set forth in part in the description which follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned by routine experimentation in practicing the invention.

[0024] The present disclosure provides methods and compositions that use naphthoquinone and hydroxylamine, and in combination, are highly effective in preventing the formation of unwanted polymers in compositions comprising monomers. The observed anti-polymerization effect has been shown to be unexpectedly beneficial, meaning that the degree of inhibition of polymer formation when naphthoquinone and hydroxylamine are used in combination is greater than the degree of inhibition of polymerization when naphthoquinone and hydroxylamine are used alone, acting at the same total anti-polymerization agent concentration.

[0025] An "unexpected beneficial anti-polymerization agent combination effect" can be observed when the combination of two anti-polymerization agents (a first anti-polymerization agent and a second anti-polymerization agent) provides a polymerization inhibition level at a total anti-polymerization agent concentration that is greater than the polymerization inhibition level when the first anti-polymerization agent or the second anti-polymerization agent is used alone in an amount based on the total anti-polymerization agent concentration of the combination. For example, a first anti-polymerization agent that is used at a first concentration (e.g., 200 ppm) and provides an anti-polymerization activity of "80" at a polymerization level (e.g., polystyrene formation), and a second anti-polymerization agent that is also used at a first concentration (e.g., 200 ppm) and provides an anti-polymerization activity of "90" at a polymerization level (e.g., polystyrene formation), when the first anti-polymerization agent and the second anti-polymerization agent are used in combination at a total concentration of 200 ppm (e.g., 100 ppm each of the first anti-polymerization agent and the second anti-polymerization agent), the "expected" level of anti-polymerization activity will be "85" (the average of the polymerization levels using the first anti-polymerization agent and the second anti-polymerization agent). Thus, if the total concentration of the combination of the first anti-polymerizing agent and the second anti-polymerizing agent is less than "85" (expected average), or particularly less than "80" (first anti-polymerizing agent), the combination of anti-polymerizing agents is considered to provide "unexpected" anti-polymerization activity because each anti-polymerizing agent does not antagonize the other anti-polymerizing agent, and the combination performs better than the average of the two, or performs better than the first anti-polymerizing agent or the second anti-polymerizing agent at the same concentration. When the first anti-polymerizing agent and the second anti-polymerizing agent are used in combination, this unexpected level of polymerization inhibition may optionally be referred to as "synergistic," such as "synergistic anti-polymerization activity." Testing for unexpected anti-polymerization activity may be performed even if the first anti-polymerizing agent and the second anti-polymerizing agent are used in combination at different concentrations. Here, the "expected" anti-polymerization activity may also be calculated based on the average values ​​of the first anti-polymerizing agent and the second anti-polymerizing agent used individually at the total anti-polymerizing agent concentration. The beneficial anti-polymerization activity of the combination of naphthoquinone and hydroxylamine may result from the ability of the combination to very effectively inhibit and retard polymer formation in a monomer composition, where such activity may be observed over a period of time, as exemplified herein.

[0026] The ability of the naphthoquinone and hydroxylamine combination of the present invention can be expressed as a percentage (%) reduction compared to naphthoquinone and hydroxylamine used at a total concentration or compared to the average value of naphthoquinone and hydroxylamine used at each total concentration. For example, using the test method described herein, the formation of polymers in a monomer composition containing a total concentration of naphthoquinone and hydroxylamine can be determined under conditions that promote polymer formation and optionally over a period of time (measured in % w / w). The amount of polymer formed in the combined composition of naphthoquinone and hydroxylamine (each used at half the total concentration) is then determined and compared to the average value of naphthoquinone and hydroxylamine or to the naphthoquinone or hydroxylamine used at each total concentration. In an embodiment, the combination shows a polymerization reduction of 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more, such as up to about 90% or more, or a reduction in the % amount within any of these numerical values, compared to the average value or compared to naphthoquinone and hydroxylamine used at each total concentration.

[0027] For example, when a combination of naphthoquinone and hydroxylamine is introduced into a hydrocarbon composition comprising a polymerizable monomer or a compound capable of forming a polymerizable monomer, such as a hydrocarbon composition comprising styrene, an unexpected (e.g., synergistic) anti-polymerization effect can be observed. The combination can be introduced into a hydrocarbon composition undergoing refining, or can be introduced into a refined hydrocarbon composition, such as a hydrocarbon composition being transported or stored.

[0028] As used herein, "anti-polymerization agents" are compounds that can reduce the formation of polymers by one or more free radical polymerizable compounds. Anti-polymerization agents can be more specifically classified into polymerization inhibitors and polymerization retarders. In the presence of polymerizable monomers, polymerization inhibitors inhibit the formation of polymers by these monomers during the induction time. After the induction time has passed, the formation of polymers occurs at a rate substantially the same as the rate at which the polymerization inhibitor is formed in the absence of the polymerization inhibitor. Polymerization retarders do not exhibit an induction time, but instead, once added to a polymerizable monomer composition, reduce the rate of polymer formation relative to the rate at which it is formed in the absence of the composition composition. In contrast to polymerization retarders, polymerization inhibitors are generally consumed rapidly. Although polymerization retarders slow down the rate of polymerization reactions, they are not as effective as polymerization inhibitors. However, polymerization retarders are generally not consumed as quickly as polymerization inhibitors. The combination of naphthoquinone and hydroxylamine components of the present invention can provide a beneficial anti-polymerization effect, thereby reducing polymer formation in the presence of a monomer-containing composition by inhibiting and retarding polymer formation. This beneficial activity can be observed over a period of time, as exemplified herein.

[0029] Aspects of the present disclosure provide compositions for inhibiting monomer polymerization, the compositions comprising naphthoquinone and hydroxylamine. Compositions including these components (and any one or more optional components) can be in a desired form, such as in liquid form, dry form or as a suspension or dispersion. Naphthoquinone and hydroxylamine can be in a desired physical state in the composition, such as a dissolved state, a partially dissolved state, a suspended state or a dry mixture. Moreover, naphthoquinone and hydroxylamine can be in a desired form in the composition, such as optionally in a granular form. If one or more components are in a granular form, the particles can be optionally described in terms of particle size (e.g., particles of a size range) and / or shape. In the case of understanding the physical properties of each compound, the form of the composition and the state of the components thereof can be selected by selecting naphthoquinone and hydroxylamine. The form of the composition and the state of the components thereof can also be affected by including one or more optional components (such as a solvent or a solvent mixture or other excipient compounds (such as a surfactant, a dispersant, etc.) The form of the composition and the state of the components therein can also be affected by temperature, and the properties of the composition can optionally be described in the environment of a specific temperature (e.g., at storage temperature (such as 5°C or below), at room temperature (25°C), or at temperatures used for synthesis and / or processing of monomers (e.g., about 100°C or higher, about 150°C, about 175°C, etc.)).

[0030] Compositions including naphthoquinone and hydroxylamine can optionally include other components in the composition (e.g., described as a composition "comprising" naphthoquinone and hydroxylamine). For example, such compositions can include other components such as solvents, surfactants, dispersants, etc. If optional components are present in the composition, they can be described in terms of weight relative to one or more of the naphthoquinone and hydroxylamine in the composition. The optional components can be present in an amount greater than the weight of either naphthoquinone and hydroxylamine, or less than the amount of either naphthoquinone and hydroxylamine, or the total amount of naphthoquinone and hydroxylamine.

[0031] As used herein, the term "optional" or "optionally" means that the subsequently described object (e.g., compound) or event (e.g., process step), amount or circumstance can but need not occur, and that the description includes instances where the object, event, amount or circumstance occurs and instances where it does not.

[0032] The compositions of the present disclosure may include those recited compounds, and may optionally include other components of the composition, but in very small amounts (e.g., described as a composition consisting "essentially of the recited components"). For example, such compositions may include one or more other components, but in an amount no greater than about 1% by weight, about 0.5% by weight, or about 0.1% by weight of the total composition. A composition consisting essentially of naphthoquinone, hydroxylamine, and solvent may optionally include one or more other components, but in an amount less than about 1% by weight of the total composition. In a composition "consisting of the recited components," no measurable amount of other components other than the recited components are present.

[0033] Likewise, in some embodiments, the chemistry of the disclosed compounds, including naphthoquinone and hydroxylamine, may be described in terms of compounds that are "consisting of certain atoms or certain chemical groups." For example, in embodiments of the present disclosure, a compound such as a hydroxylamine component may be composed of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), and will not have any other types of atoms in the compound besides C, H, O, and N. As another example, a compound composed of a hydrocarbyl group, a hydroxyl group, and an amine group would not have any other chemical groups besides these.

[0034] As used herein, the terms "substantially" and "consisting essentially of" used in describing embodiments of the present disclosure to modify, for example, the type or amount of an ingredient in a composition, a property, a measurable amount, a method, a position, a value, or a range, refer to changes that do not affect the entire composition, property, amount, method, position, value, or range in a manner that invalidates the intended composition, property, amount, method, position, value, or range. Examples of intended properties include, by way of non-limiting example only, dispersibility, stability, rate, solubility, and the like; intended values ​​include weight of added components, concentration of added components, and the like. Effects on the modified process include effects caused by changes in the type or amount of materials used in the process, variability in machine settings, effects of environmental conditions on the process, and the like (where the manner or degree of the effects does not negate one or more of the intended properties or results), and similar approximate considerations. Where modified by the terms "substantially" or "consisting essentially of", the appended claims include equivalents of these types and amounts of materials.

[0035] As used herein, the term "about" used in describing the embodiments of the present disclosure to modify, for example, the amount of ingredients in the composition, concentration, volume, process temperature, process time, yield, flow rate, pressure and similar values ​​and ranges thereof, means that it can be, for example, by typical measurement and processing procedures for preparing compounds, compositions, concentrates or formulations for use; by errors due to negligence in these procedures; by differences in the manufacture, source or purity of the starting materials or ingredients used to carry out the method, and similar considerations. The term "about" also encompasses amounts that differ from a specific starting concentration or mixture due to aging of the formulation, and amounts that differ from a specific starting concentration or mixture due to mixing or processing the formulation. When modified with the term "about", the attached claims include equivalents of these amounts. In addition, unless the context clearly limits, in the case of using "about" to describe any range of values, such as "about 1 to 5", the enumeration means "1 to 5" and "about 1 to about 5" and "1 to about 5" and "about 1 to 5".

[0036] Some R groups in the formula of the present disclosure may include hydrocarbon-containing groups such as alkyl groups (including linear, branched and cyclic alkyl groups), aryl groups, alkylaryl groups (e.g., ethyl-benzyl), arylalkyl groups (e.g., propyl-phenyl) and combinations thereof. Cyclic alkyl or aryl groups may have fused structures, such as decahydronaphthalene, naphthalene, tetradecahydroanthracene, anthracene, etc. In some embodiments, the hydrocarbon group of the formula of the present disclosure may be defined by the number of carbon atoms in the group, such as 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbons, 1 to 6 carbons, 1 to 5 carbons, 1 to 4 carbons, or 1 to 3 carbons.

[0037] The compositions and methods of the present disclosure include or use naphthoquinones. In embodiments, the compositions and methods of the present disclosure use one or more naphthoquinones having chemical structures based on 1,4-naphthoquinone and 1,2-naphthoquinone structures according to Formula III and Formula IV, respectively.

[0038]

[0039] In embodiments, in Formula III and Formula IV, R 1 -R 6 is -H, providing compounds 1,4-naphthoquinone and 1,2-naphthoquinone.

[0040] Alternatively, R 1 , R 2 , R 3 or R 4 Two adjacent groups (i.e., R 1 and R 2 ; R 2 and R 3 ; or R 3 and R4 ) to form one or more ring structures. This can provide, for example, anthracene, a fused ring structure derived from naphthoquinone.

[0041] The compositions and methods of the present disclosure include or use naphthoquinones. In embodiments, the compositions and methods of the present disclosure use one or more naphthoquinones having chemical structures based on 1,4-naphthoquinone and 1,2-naphthoquinone structures according to Formula III and Formula IV, respectively.

[0042] In embodiments, in Formula III and Formula IV, R 1 -R 6 is -H and provides compounds 1,4-naphthoquinone and 1,2-naphthoquinone, respectively.

[0043] In an embodiment, R 1 -R 6 One or more of is a chemical group other than -H, such as a chemical group selected from alkyl, aryl, alkylaryl and arylalkyl groups of 1 to 24 carbon atoms.

[0044] In an embodiment, the naphthoquinone is an aminated naphthoquinone. For example, in Formula III or Formula IV, the naphthoquinone may include one or more amine groups, wherein -R 5 and / or -R 6 One or both of them are -NR 5 R 6 , where R 5 and R 6 Selected from hydrogen, alkyl, aryl, alkylaryl and arylalkyl groups having from 1 to 24 carbon atoms. Exemplary aminated naphthoquinone anti-aggregants may have the following general chemical structures: 2-amino-1,4-naphthoquinone, 2,3-diamino-1,4-naphthoquinone, 2-amino-1,3-naphthoquinone, 4-amino-1,3-naphthoquinone, 2,4-diamino-1,3-naphthoquinone, 3-amino-1,2-naphthoquinone, 4-amino-1,2-naphthoquinone and 3,4-diamino-1,3-naphthoquinone.

[0045] Exemplary aminated naphthoquinones are described in Applicant's U.S. Patent No. 11,312,792 (Masere, April 26, 2022), the disclosure of which is incorporated herein by reference.

[0046] The compositions and methods of the present disclosure include or use hydroxylamine and naphthoquinone, which together in a monomer-containing composition provide an unexpected (eg, synergistic) anti-polymerization effect.

[0047] Hydroxylamine compounds have one or more amine groups bonded to a hydroxyl group. In some embodiments, the hydroxylamine compound is a "primary hydroxylamine," which refers to a compound having a nitrogen atom bonded to a hydroxyl group (-OH), hydrogen (-H), and a chemical group that is not a hydroxyl group or hydrogen (such as a hydrocarbon-containing group). In some embodiments, the hydroxylamine compound is a "secondary hydroxylamine," which refers to a compound having a nitrogen atom bonded to a hydroxyl group (-OH) and two chemical groups that are not a hydroxyl group or hydrogen (such as a hydrocarbon-containing group), or alternatively the secondary hydroxylamine is a cyclic compound in which the nitrogen is a heteroatom in the ring structure and is also bonded to a hydroxyl group.

[0048] Hydroxylamines can also be described in terms of atomic composition, for example, hydroxylamines have one or more primary hydroxylamine groups and / or one or more secondary hydroxylamine groups, and at least 1, at least 2, at least 3, or at least 4 carbon atoms, and up to 60, up to 48, up to 36, up to 24, up to 18, up to 15, or up to 12 carbon atoms. In some preferred embodiments, the hydroxylamine has a carbon number in the range of 3 to 24, in the range of 3 to 18, or in the range of 3 to 15.

[0049] The hydroxylamine may contain one or more oxygen atoms, wherein at least one of the oxygen atoms is in the form of a hydroxyl group bonded to the nitrogen on the hydroxylamine group. In embodiments, the hydroxylamine has a number of oxygen atoms in the range of 1 to 8, in the range of 1 to 6, in the range of 1 to 4, or in the range of 1 to 3. In embodiments where the hydroxylamine contains two or more oxygen atoms, most or all of the oxygen atoms may be in the form of hydroxyl groups in the hydroxylamine.

[0050] Hydroxylamine can be composed of certain atoms but not others. In some embodiments, hydroxylamine is composed of nitrogen, carbon, oxygen, and hydrogen atoms.

[0051] In an embodiment, the hydroxylamine has the formula I: HO-NR 1 R 2 , where R 1 and R 2 At least one or both of are carbon-containing groups having 1 to 12 carbon atoms, optionally substituted with one or more hydroxyl groups, wherein if R 1 or R 2 If it is not a carbon-containing group, it is -H. Formula I (HO-NR 1 R 2 ) 1 It can be selected from (i) C1-C12 alkyl groups, (ii) C1-C8 alkyl groups, and (iii) C1-C6 alkyl groups, wherein (i) to (iii) have a linear, branched or cyclic structure, or a combination thereof. Formula I (HO-NR 1 R 2) 2 It can be selected from (iv) -H and C1-C12 alkyl groups, (v) -H and C1-C8 alkyl groups, or (vi) -H and C1-C6 alkyl groups, wherein the alkyl groups in (iv) to (vi) have a linear, branched or cyclic structure, or a combination thereof, and wherein any one or more of the alkyl groups in (i) to (vi) are optionally substituted by one or more hydroxyl groups.

[0052] In an embodiment, Formula I (HO-NR 1 R 2 ) 1 or / and R 2 One or both of R may be selected from linear, branched and cyclic alkyl, aryl, alkyl-aryl and aryl-alkyl C1-C12 groups. 1 or / and R 2 The radicals include those such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, cyclohexyl, 1-, 2- and 3-methylbutyl, 1,1-, 1,2- or 2,2-dimethylpropyl, 1-ethyl-propyl, 1-, 2-, 3- or 4-methylpentyl. , 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl or 3,3-dimethylbutyl, 1-ethylbutyl or 2-ethylbutyl, 1-ethyl-1-methylpropyl and 1,1,2-trimethylpropyl or 1,2,2-trimethylpropyl, methylcyclopentyl; heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 4,4-dimethylpentyl, cycloheptyl, 1-methylcyclohexyl and 2-methylcyclohexyl; octyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 5-ethyl hexyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3-ethyl-2-methylpentyl, 3-ethyl-3-methylpentyl, 2,2,3-trimethylpentyl, 2,2,4-trimethylpentyl, 2,3,3-trimethylpentyl, 2,3,4-trimethylpentyl and 2,2,3,3-tetramethylbutyl.

[0053] In an embodiment, Formula I (HO-NR 1 R 2 )1 or / and R 2 One or both of may be independently selected from hydroxylated linear, branched and cyclic alkyl, aryl, alkyl-aryl and aryl-alkyl C1-C12 groups. In some embodiments, R 1 and R 2 One or both of them have the formula: -(CR 10 2 ) q (CHOH)(CH 2 ) z R 11 , where R 10 is independently selected from -H and alkyl, wherein q and z are independently (-) (covalent bond), or an integer in the range of 1 to 12, and R 11 is selected from C1-C12 linear, branched or cyclic alkyl, aryl, alkyl-aryl and aryl-alkyl optionally substituted with one or more hydroxyl groups. In embodiments, q and z are independently (-), 1 or 2. In some embodiments, R 10 =H; q is 1; z is (-); and R 11 is selected from C1-C12 straight chain, branched or cyclic alkyl, aryl, alkyl-aryl and aryl-alkyl groups. Exemplary alkyl, alkyl-aryl and aryl-alkyl groups are described herein. Formula: -(CR 10 2 ) q (CHOH)(CH 2 ) z R 11 Exemplary substances include the following groups:

[0054]

[0055] In an embodiment, the carbon-containing group of formula I (HO-NR 1 R 2 ) 1 or / and R 2 One or both of R contain an aryl group. 1 and R 2 One or both of them have the formula V:

[0056]

[0057] Where R 6 are independently selected from -H, -OH and alkyl, wherein v is an integer in the range of 1 to 6, R 7 are independently selected from -H, -OH and alkyl, wherein q is an integer in the range of 1 to 5.

[0058] In an embodiment, -(CHR 6 ) v - includes the formula exemplified by the following groups -(CR 10 2 ) q (CHOH)(CH 2 ) z -:

[0059]

[0060] In some embodiments, the hydroxylamine is selected from benzylhydroxylamine, N-phenethyl-hydroxylamine, N-(3-phenyl-propyl)-hydroxylamine, N-(4-phenyl-butyl)-hydroxylamine, N-(5-phenyl-pentyl)-hydroxylamine, N-(6-hexyl-propyl)-hydroxylamine, N-(3-phenyl-2-methyl-propyl)-hydroxylamine, and N-(4-phenyl-3-methyl-butyl)-hydroxylamine;

[0061] In some embodiments, the hydroxylamine is selected from dibenzylhydroxylamine, N,N-bis(phenylethyl)hydroxylamine, N,N-bis(3-phenylpropyl)hydroxylamine, N,N-bis(4-phenyl-butyl)-hydroxylamine, N,N-bis(5-phenyl-pentyl)-hydroxylamine, N,N-bis(6-hexyl-propyl)-hydroxylamine, N,N-bis(3-phenyl-2-methyl-propyl)-hydroxylamine, and N,N-bis(4-phenyl-3-methyl-butyl)-hydroxylamine.

[0062] In some embodiments, the hydroxylamine is selected from N-(2-phenyl-1-hydroxy-ethyl)hydroxylamine, N-(3-phenyl-2-hydroxy-propyl)-hydroxylamine, N-(4-phenyl-2-hydroxy-butyl)-hydroxylamine, N-(5-phenyl-2-hydroxy-pentyl)-hydroxylamine, N-(6-hexyl 2-hydroxy-propyl)-hydroxylamine,

[0063] In some embodiments, the hydroxylamine is selected from N,N-bis(2-phenyl-1-hydroxy-ethyl)hydroxylamine, N,N-bis(3-phenyl-2-hydroxy-propyl)-hydroxylamine, N,N-bis(4-phenyl-2-hydroxy-butyl)-hydroxylamine, N,N-bis(5-phenyl-2-hydroxy-pentyl)-hydroxylamine and N,N-bis(6-hexyl 2-hydroxy-propyl)-hydroxylamine.

[0064] In some embodiments, the compound of Formula I is selected from N,N-dimethylhydroxylamine, N-methyl-N-ethylhydroxylamine, N-methyl-N-propylhydroxylamine, N-methyl-N-isopropylhydroxylamine, N-methyl-N-propylhydroxylamine, N-methyl-N-butylhydroxylamine, N-methyl-N-isobutylhydroxylamine, N-methyl-N-tert-butylhydroxylamine, N,N-diethylhydroxylamine, N-ethyl-N-propylhydroxylamine, N-ethyl-N-isopropylhydroxylamine, N-ethyl-N-propylhydroxylamine, N-ethyl-N-butylhydroxylamine, N-ethyl-N-isobutylhydroxylamine, N-ethyl-N-tert-butylhydroxylamine, N,N-dipropylhydroxylamine, N,N-diisopropylhydroxylamine, N-propyl-N-butylhydroxylamine, N-isopropyl-N-butylhydroxylamine, N-propyl-N-isobutylhydroxylamine, N-propyl-N-tert-butylhydroxylamine, N-isopropyl-N-isobutylhydroxylamine and N-isopropyl-N-tert-butylhydroxylamine.

[0065] In some embodiments, the compound of Formula I is selected from N-methylhydroxylamine, N-ethylhydroxylamine, N-propylhydroxylamine, N-isopropylhydroxylamine, N-butylhydroxylamine, N-isobutylhydroxylamine, N-tert-butylhydroxylamine, N-sec-butylhydroxylamine, N-pentylhydroxylamine, N-cyclopentylhydroxylamine, N-isopentylhydroxylamine, N-neopentylhydroxylamine, N-hexylhydroxylamine, N-cyclohexylhydroxylamine, N-1-methylbutylhydroxylamine, N-2-methylbutylhydroxylamine and N-3-methylbutylhydroxylamine, N-1,1-dimethylpropylhydroxylamine, N-1,2-dimethylpropylhydroxylamine or N-2,2-dimethylpropylhydroxylamine, N-1-ethyl- Propylhydroxylamine, 1-methylpentylhydroxylamine, 2-methylpentylhydroxylamine, 3-methylpentylhydroxylamine or 4-methylpentylhydroxylamine, N-1,1-dimethylbutylhydroxylamine, N-1,2-dimethylbutylhydroxylamine, N-1,3-dimethylbutylhydroxylamine, N-2,2-dimethylbutylhydroxylamine, N-2,3-dimethylbutylhydroxylamine or N-3,3-dimethylbutylhydroxylamine, N-1-ethylbutylhydroxylamine or N-2-ethylbutylhydroxylamine, N-1-ethyl-1-methyl-propylhydroxylamine and N-1,1,2-trimethylpropylhydroxylamine or N-1,2,2-trimethylpropylhydroxylamine and N-methylcyclopentylhydroxylamine.

[0066] In some embodiments, the compound of Formula I is selected from N-hydroxymethylhydroxylamine, N-1-hydroxyethylhydroxylamine or N-2-hydroxyethylhydroxylamine, N-1-hydroxypropylhydroxylamine, N-2-hydroxypropylhydroxylamine or N-3-hydroxypropylhydroxylamine, N-1-hydroxypropylhydroxylamine or N-2-hydroxypropylhydroxylamine, N-1-hydroxybutylhydroxylamine, N-2-hydroxybutylhydroxylamine, N-3-hydroxybutylhydroxylamine or N-4-hydroxybutylhydroxylamine, N -1-hydroxyisobutylhydroxylamine, N-2-hydroxyisobutylhydroxylamine or N-3-hydroxyisobutylhydroxylamine, N-1-hydroxysec-butylhydroxylamine, N-2-hydroxysec-butylhydroxylamine or N-3-hydroxysec-butylhydroxylamine, N-2-hydroxy-tert-butylhydroxylamine and N-1-N-hydroxypentylhydroxylamine, N-2-N-hydroxypentylhydroxylamine, N-3-N-hydroxypentylhydroxylamine, N-4-N-hydroxypentylhydroxylamine or N-5-N-hydroxypentylhydroxylamine;

[0067] In some embodiments, the compound of Formula I is selected from N,N-bis(hydroxymethyl)hydroxylamine, N,N-bis(1-hydroxyethyl or 2-hydroxyethyl)hydroxylamine, N,N-bis(1-hydroxypropyl, 2-hydroxypropyl or 3-hydroxypropyl)hydroxylamine, N,N-bis(1-hydroxypropyl or 2-hydroxypropyl)hydroxylamine, N,N-bis(1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl or 4-hydroxybutyl)hydroxylamine, N,N-bis(1-hydroxyisobutyl, 2-hydroxyisobutyl or 3-hydroxyisobutyl)hydroxylamine, N,N-bis(1-hydroxysec-butyl, 2-hydroxysec-butyl or 3-hydroxysec-butyl)hydroxylamine, N,N-bis(2-hydroxy-tert-butyl)hydroxylamine and N,N-bis(1-N-hydroxypentyl, 2-N-hydroxypentyl, 3-N-hydroxypentyl, 4-N-hydroxypentyl or 5-N-hydroxypentyl)hydroxylamine.

[0068] In some embodiments, the hydroxylamine has Formula II:

[0069]

[0070] Where X is -(CHR 5 ) w -, where R 5 Selected from -H, R 3 and R 4 , R 3 is selected from -H and alkyl, and R 4 is selected from -H and -OH, y is 0 or an integer in the range of 1 to 3, z is 0 or an integer in the range of 1 to 3, and w is an integer in the range of 1 to 4.

[0071] Exemplary materials of Formula II include N-hydroxypyrrolidine, N-hydroxypiperidine, azepanol, and azocanol.

[0072] Other exemplary materials of Formula II include alkylated (such as having C1-C6 alkylation) N-hydroxypyrrolidines, N-hydroxypiperidines, azepanols and azocanols, hydroxylated N-hydroxypyrrolidines, N-hydroxypiperidines, azepanols and azocanols, and compounds having both alkylation and hydroxylation.

[0073] The hydroxylamines of the present disclosure are generally in liquid or solid form at room temperature (25°C). Some hydroxylamines having about 12 carbon atoms or an alkyl chain length of about 12 may be in solid form at room temperature. In some embodiments, the melting point of the hydroxylamine compounds of the present disclosure is in the range of about -50°C to about 200°C, in the range of about -30°C to about 150°C, or in the range of about -10°C to about 125°C. In some embodiments, the boiling point of the hydroxylamine compounds of the present disclosure is about 100°C or higher, about 110°C or higher, about 120°C or higher, about 130°C or higher, about 140°C or higher, about 150°C or higher, about 160°C or higher, about 170°C or higher, about 175°C or higher, about 180°C or higher, about 185°C or higher, about 190°C or higher, 195°C or higher, such as in the range of about 100°C to about 300°C or about 150°C to about 250°C.

[0074] The amount of naphthoquinone and hydroxylamine in the composition can be described in various ways, such as by weight percentage (wt%) of each component in the composition or by molar amount of the compound. These compounds can also be described according to the weight ratio in the composition or according to the amount relative to each other in the composition.

[0075] In some embodiments, naphthoquinone and hydroxylamine are used in the composition in a desired molar ratio, such as in a range of 10:1 to 1:10, in a range of 5:1 to 1:5, in a range of 2.5:1 to 1:2.5, in a range of 2:1 to 1:2, in a range of 1.5:1 to 1:1.5, in a range of 1.25:1 to 1:1.25, or in a range of 1.1:1 to 1:1.1. In some embodiments, naphthoquinone and hydroxylamine are used in approximately the same molar amount.

[0076] The naphthoquinone and hydroxylamine may be present in the composition together with a solvent or a combination of solvents. The solvent or combination of solvents may be selected such that at least one of the naphthoquinone and hydroxylamine is soluble in the solvent or combination of solvents. If the hydroxylamine is a liquid at ambient conditions, the solvent may be selected such that it is miscible with the hydroxylamine.

[0077] In embodiments, hydroxylamine may also be used as a solvent and may be used to solvate naphthoquinone. In these embodiments, hydroxylamine may be used in a desired amount relative to naphthoquinone, or even in an amount greater than naphthoquinone.

[0078] The composition may also include one or more solvents. Useful solvents include any solvent in which the combination of naphthoquinone and hydroxylamine is soluble or stably suspended. In some embodiments, the solvent or solvent combination may be selected from water-soluble or water-miscible solvents, such as diol-based solvents and hydrophobic solvents, such as aromatic solvents, paraffin solvents, or mixtures thereof.

[0079] Exemplary glycol solvents include, but are not limited to, C 1 -C 8 Glycols such as ethylene glycol, propylene glycol, diethylene glycol, and triethylene glycol; ethers of such glycols such as diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycols, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and low molecular weight polypropylene glycols, and the like, and combinations thereof. Commercial solvents such as Butyl Carbitol and Butyl CELLOSOLVE can be used and are available from DOW TM , which mainly contains Butyl CARBITOL TM , which is mainly composed of ethylene glycol monobutyl ether.

[0080] Other exemplary hydrophobic solvents include heavy aromatic naphtha, toluene, ethylbenzene, and isomeric hexanes, and mixtures of two or more thereof.

[0081] The amount of one or more solvents in the composition comprising naphthoquinone and hydroxylamine is not particularly limited. In some embodiments, the amount of one or more solvents in the composition may be about 10% to 50% by weight, about 20% to 50% by weight, or about 25% to 50% by weight, or about 10% to 40% by weight, or about 10% to 30% by weight, or about 20% to 40% by weight, or about 25% to 40% by weight of the total composition.

[0082] In some embodiments, the composition comprises naphthoquinone in an amount ranging from 5% to 45% by weight; hydroxylamine in an amount ranging from 5% to 45% by weight; and a solvent or solvent combination in an amount ranging from 10% to 90% by weight. In some embodiments, the composition comprises naphthoquinone in an amount ranging from 15% to 35% by weight; hydroxylamine in an amount ranging from 15% to 35% by weight; and a solvent or solvent combination in an amount ranging from 30% to 70% by weight. In some embodiments, the composition comprises naphthoquinone in an amount ranging from 20% to 30% by weight; hydroxylamine in an amount ranging from 20% to 30% by weight; and a solvent or solvent combination in an amount ranging from 30% to 70% by weight. Compositions comprising naphthoquinone and hydroxylamine in concentrations above the "working" concentrations (typically measured in ppm) of naphthoquinone or hydroxylamine may be referred to as "concentrates" or "raw" compositions.

[0083] Any desired method may be used to prepare the compositions of the present disclosure. In some modes of preparation, a solution of naphthoquinone or hydroxylamine and a solvent may first be obtained by the user, such as a commercial preparation, and then the naphthoquinone or hydroxylamine is subsequently added, such as in a point-of-use procedure.

[0084] A composition comprising a mixture of naphthoquinone and hydroxylamine, optionally containing a solvent, can be provided as a "shelf-stable" composition, and then the composition is subsequently used in a process for inhibiting monomer polymerization. For example, the method of the present disclosure can include the steps of preparing a composition of naphthoquinone or hydroxylamine, then storing the composition for a period of time, and then using the composition in a process for inhibiting monomer polymerization.

[0085] A method of mitigating polymerization of monomers in a composition containing monomers can be performed by adding naphthoquinone and hydroxylamine to the composition containing polymerizable monomers. Naphthoquinone and hydroxylamine inhibit polymerization of polymerizable monomers, and their beneficial use in combination provides a greater degree of polymerization inhibition than the additive inhibition of the inhibitors used individually at corresponding concentrations. In other words, the combination of naphthoquinone and hydroxylamine provides an unexpected (e.g., synergistic) effect of inhibiting polymerization of monomers, which in turn provides benefits for various processes where it is desired to inhibit polymerization of monomers.

[0086] As noted herein, naphthoquinones and hydroxylamines, when used together in a monomer-containing composition, can provide unexpected (e.g., synergistic) effects, which in turn can eliminate the need for one or more other types of polymerization inhibitors to be used concomitantly with the naphthoquinones and hydroxylamines. Other types of polymerization inhibitors that may not be used at the same time as the naphthoquinones and hydroxylamines or that may be used in very small concentrations can include compounds containing nitroxides, amine oxides, nitro groups, nitroso groups, and nitrone groups.

[0087] For example, if present, any nitroxide, amine oxide, nitro, nitroso and nitrone containing compounds may optionally be present in the working composition with the monomers in an amount of less than 50 ppm, less than 25 ppm, less than 10 ppm, less than 5 ppm, less than 2.5 ppm, less than 2 ppm, less than 1.5 ppm, less than 1 ppm, less than 0.75 ppm or less than 0.5 ppm.

[0088] Exemplary nitroxide-containing inhibitors include di-tert-butyl nitroxyl, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl (HTMPO), 4-oxo-2,2,6,6-tetramethylpiperidinyl-1-oxyl (OTEMPO), which can be excluded from the additive composition of the present disclosure or added to the monomer composition without accompanying the naphthoquinone and hydroxylamine. These types of compounds may not be used at the same time as the naphthoquinone and hydroxylamine, or may be used in very small concentrations, as indicated herein.

[0089] Exemplary hydroxylamine-containing polymerization inhibitors include, but are not limited to, 1-hydroxy-2,2,6,6-tetramethylpiperidine (TEMPOH), 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine (HTMPOH), and 1-hydroxy-4-oxo-2,2,6,6-tetramethylpiperidine (OTEMPOH), N,N-diethylhydroxylamine, and N-isopropylhydroxylamine. These types of compounds may not be used at the same time as naphthoquinone and hydroxylamine, or may be used in very small concentrations, as noted herein.

[0090] Exemplary nitro-containing polymerization inhibitors include, but are not limited to, nitrobenzene, nitrophenol, dinitrophenol, 2,4-dinitro-6-sec-butylphenol, 2,4-dinitro-o-cresol, and diphenylpicrylhydrazyl. These types of compounds may not be used at the same time as naphthoquinone and hydroxylamine, or may be used in very small concentrations, as noted herein.

[0091] Exemplary nitroso-containing polymerization inhibitors include, but are not limited to, nitrosobenzene, nitrosophenol, dinitrosophenol, dinitrosotoluene, nitrosophenylhydroxylamine. These types of compounds may not be used at the same time as naphthoquinone and hydroxylamine, or may be used in very small concentrations, as indicated herein.

[0092] Although it is preferred to use naphthoquinones and hydroxylamines to provide anti-polymerization without the use of nitroxide, amine oxide, nitro, nitroso, and nitrone-containing compounds, or optionally with very small amounts of such compounds, the methods of the present disclosure do not exclude the use of a composition containing monomers that has been previously treated with a nitroxide, amine oxide, nitro, nitroso, or nitrone-containing compound, nor do they exclude methods in which such compounds are added all at once after the naphthoquinone and hydroxylamine treatment. For example, the present disclosure contemplates a composition containing hydrocarbons and monomers that has been previously treated with, for example, a nitroxide compound, and then, after a period of time in which the nitroxide compound loses its effectiveness, naphthoquinones and hydroxylamines are added to the composition containing hydrocarbons and monomers. Optionally, the present disclosure also contemplates a composition containing hydrocarbons and monomers that has been treated with naphthoquinones and hydroxylamines and then subsequently treated with a compound other than naphthoquinones and hydroxylamines.

[0093] The polymerizable monomers that are inhibited from polymerization may include vinyl or ethylenically unsaturated groups. For example, naphthoquinone and hydroxylamine may be added to a composition comprising one or more of the following polymerizable monomers: acrylic acid, acrylonitrile, alkylated styrene, butadiene, chloroprene, divinylbenzene, ethyl acrylate, ethyl methacrylate, isoprene, methacrylic acid, methyl methacrylate, methyl acrylate, alpha-methylstyrene, methacrylonitrile, styrene, styrene sulfonic acid, vinyltoluene, and vinylpyridine.

[0094] The polymerizable monomers may be present in a crude mixture of compounds, a semi-refined mixture of compounds, or a fully refined mixture of compounds. For example, naphthoquinones and hydroxylamines may be added to a process stream comprising polymerizable monomers. In the method, components may be added before, during, or after a processing step (such as distillation) (or a combination thereof), wherein the compounds in the composition are separated from one another. The components may inhibit polymerization of the monomers at any one or more stages in the processing system and minimize fouling of the equipment.

[0095] Alternatively, the naphthoquinone and hydroxylamine components can be added to a process stream that includes a compound capable of polymerizing a monomer. For example, in a composition that includes a compound capable of forming a polymerizable monomer as an unwanted by-product, if a polymerizable monomer is indeed formed as a by-product, the presence of naphthoquinone and hydroxylamine can inhibit the polymerization of the monomer and thus minimize fouling of the equipment.

[0096] In some modes of practice, naphthoquinone and hydroxylamine are introduced into a composition containing monomers to provide the desired amount of each agent in the composition. The naphthoquinone and hydroxylamine can be introduced simultaneously, such as delivered from a composition of mixed components, or can be delivered separately or partially in combination, either sequentially or in an overlapping manner.

[0097] If the naphthoquinone and the hydroxylamine are introduced sequentially into the monomer-containing composition, the addition is preferably performed to allow the naphthoquinone and hydroxylamine combination to provide an unexpected (eg, synergistic) anti-polymerization effect to the composition.

[0098] The components are finally introduced into the composition containing monomers to provide naphthoquinone and hydroxylamine of the desired concentration. For example, at a polymerizable monomer concentration in the range of 50ppm to 200ppm, naphthoquinone is present in the composition in an amount in the range of 50ppm to 500ppm, and hydroxylamine is present in the composition in an amount in the range of 50ppm to 500ppm. In some practical modes, naphthoquinone is present in the composition in an amount in the range of 75ppm to 400ppm, and hydroxylamine is present in the composition in an amount in the range of 75ppm to 400ppm. In some practical modes, naphthoquinone is present in the composition in an amount in the range of 100ppm to 300ppm, and hydroxylamine is present in the composition in an amount in the range of 100ppm to 300ppm. In some practical modes, naphthoquinone is present in the composition in an amount in the range of 150ppm to 250ppm, and hydroxylamine is present in the composition in an amount in the range of 150ppm to 250ppm.

[0099] The term "fouling" refers to the formation of polymers, prepolymers, oligomers and / or other materials that are insoluble in the feed stream and / or precipitate out of the feed stream and deposit on the equipment under the operating conditions of the equipment. Subsequently, the naphthoquinones and hydroxylamines and compositions of the present disclosure may be referred to as "antifoulants" because they inhibit or reduce such formation.

[0100] The naphthoquinone and hydroxylamine components may be used in conjunction with compositions containing polymerizable monomers and "process equipment" (e.g., reactors, reactor beds, piping, valves, distillation columns, trays, condensers, heat exchangers, compressors, fans, impellers, pumps, recirculators, intercoolers, sensors, etc.) that are associated with the process and that may be fouled by polymerization of the monomers. The term also includes collections of these components where more than one component is part of a "system."

[0101] In a preferred method of use, the composition of naphthoquinone, hydroxylamine and optional solvent disclosed herein is used together with a process involving a distillation tower for separating and purifying vinyl monomers. For example, in a process known in the art, ethylbenzene can be subjected to a catalytic dehydrogenation reaction, thereby causing the formation of styrene. The reaction product containing styrene also contains other compounds, such as aromatic compounds (such as toluene and benzene), unreacted ethylbenzene and other materials (such as polymers). This mixture of compounds is usually fractionated using one or more distillation towers. Typically, heat is used to help separate the components in the distillation tower. After distillation, the fractionated components can be separated into pure product streams with higher purity.

[0102] The naphthoquinone and hydroxylamine composition can be introduced into the stream leading from the reaction bed to the distillation column, or it can be added directly to the distillation column. The inhibitor composition can be added before heating the monomer composition or while heating the monomer composition in the distillation column. In some embodiments, the boiling point of the naphthoquinone and / or hydroxylamine is greater than the desired compound (e.g., a monomer such as styrene) subjected to the distillation column, and during the distillation process, the desired compound is separated from the hydroxylamine due to the temperature difference. In embodiments, the boiling point difference between the compound of interest and the naphthoquinone and / or hydroxylamine is about 10°C or higher, about 15°C or higher, about 20°C or higher, about 25°C or higher, about 30°C or higher, about 35°C or higher, about 40°C or higher, about 45°C or higher, or about 50°C or higher.

[0103] Alternatively, or in addition to adding the inhibitor composition during the distillation process, the inhibitor composition can be added to a distillation effluent stream, such as a purified styrene stream.

[0104] The components of naphthoquinone and hydroxylamine can be used in conjunction with "petroleum products", which refers to any hydrocarbon product obtained from an underground reservoir, any product derived therefrom, or any mixture thereof. The polymerizable monomer is present in the petroleum product or can be chemically derived from the petroleum product. Non-limiting examples of petroleum products include, but are not limited to, crude oil, crude oil after distillation, crude oil fractions, heavy oil or asphalt, hydrogenated oil, refined oil, by-products of petroleum product processing (such as pyrolysis, hydroprocessing or phase separation), or a mixture of two or more of these. Liquid petroleum products are petroleum products that are substantially liquid at 20°C.

[0105] The components of naphthoquinone and hydroxylamine can be added to or can be present in a "petroleum process stream", which refers to any petroleum product placed in petroleum process equipment and in fluid contact with its inner surface. A petroleum process stream may include one or more polymerizable monomers, or one or more polymerizable monomers that can form as by-products. A process stream can be substantially static, such as a petroleum product placed in a settler (separator) or storage container for a selected contact time, such as up to two years. A process stream can be substantially dynamic, such as a liquid petroleum product placed in a pipe during the transportation of the product from a first location to a second location. In some embodiments, the process stream includes one or more other components related to petroleum processing; such components are not particularly limited.

[0106] As used herein, the terms "petroleum process equipment", "petroleum process equipment" and similar terms mean a man-made article having an interior surface comprising metal, further wherein one or more petroleum products are in contact with a metallic fluid at any temperature for any period of time as further determined by the context. Petroleum process equipment includes articles used to remove petroleum products from underground reservoirs, to transport one or more petroleum products from a first location to a second location, or to separate, refine, treat, separate, distill, react, meter, heat, cool, or contain one or more petroleum products.

[0107] In embodiments, the composition comprising naphthoquinone and hydroxylamine is thermolytically stable and has anti-polymerization activity in a process stream or other composition containing polymerizable monomers at a temperature of about 20°C to about 400°C, e.g., about 100°C to 400°C, or about 100°C to 350°C, or about 100°C to 300°C, or about 100°C to 250°C, or about 100°C to 200°C, or about 100°C to 150°C.

[0108] In embodiments, a composition comprising naphthoquinone and hydroxylamine may be introduced into a composition having polymerizable monomers, such as a liquid petroleum process stream, in a batch, continuous, or semi-continuous manner. In some embodiments, the naphthoquinone and hydroxylamine are introduced manually; in other embodiments, their introduction is automated. In embodiments, the amount of naphthoquinone and hydroxylamine introduced in a selected time unit varies with the variable composition of the associated process stream. Such dosage variations may be performed manually by periodically testing the internal surfaces of the process equipment and then adjusting the amount of the composition up or down based on the test results; or automatically by monitoring one or more conditions inside the petroleum process equipment and signaling the need to apply more of the composition to the process stream.

[0109] In some embodiments, naphthoquinone and hydroxylamine are added to a petroleum product that is a crude oil, reduced crude oil, heavy oil, asphalt, coker feed, hydrotreater influent, hydrotreater effluent, flashed crude oil, light cycle oil, or a diesel or naphtha refinery stream. In embodiments, the compounds are added to petroleum process equipment that is typically associated with the collection, processing, transportation, or storage of one or more of crude oil, distilled crude oil, crude oil fractions, heavy oil, asphalt, coker charge, flashed crude oil, light cycle oil, or a diesel or naphtha refinery stream, including pipelines and related infrastructure for fluidly connecting process equipment items together to facilitate processing of process streams disposed therein.

[0110] Equipment containing a composition containing a polymerizable monomer treated with naphthoquinone and hydroxylamine can reduce or eliminate scaling on the interior surfaces of the equipment. In embodiments, scaling is measured as a relative increase in solid retention in the treated composition compared to solid retention in an untreated composition over the same time period. In embodiments, scaling is measured as a relative decrease in the weight or volume of precipitate produced by the same contact time period of the treated process stream in the relevant process equipment item relative to a selected contact time period of the process equipment with the corresponding untreated process stream. In other words, the reduction in scaling is a relative decrease in the measured weight or volume of solids deposited or precipitated from process equipment in contact with the treated process stream over a selected time period compared to the weight or volume of solids deposited or precipitated from the untreated process stream over the same time period.

[0111] Naphthoquinones and hydroxylamines can also inhibit unwanted polymerization and fouling of process equipment in primary fractionation processes, light ends fractionation, non-aromatic halide vinyl fractionation, process gas compression, dilution steam systems, caustic treatment towers, quench water towers, butadiene extraction, propane dehydrogenation, diesel and gasoline fuel stabilization, olefin metathesis, styrene purification, hydroxy hydrocarbon purification, or retard the polymerization of resins and compositions containing ethylenically unsaturated species.

[0112] The naphthoquinone and hydroxylamine can be added at any given point and one or more locations in the process. For example, the anti-fouling composition can be added directly at the intercooler or compressor or upstream of the intercooler or compressor. In order to inhibit or reduce fouling, naphthoquinone and hydroxylamine can be added to the process equipment continuously or intermittently as needed.

[0113] The naphthoquinones and hydroxylamines can be introduced into the desired system by any suitable method. For example, they can be added neat or in the form of a diluted solution. In some embodiments, the composition containing the naphthoquinones and hydroxylamines can be applied as a solution, emulsion, or dispersion, sprayed, dripped, poured, or injected into a desired opening in the system or onto process equipment or process condensate. In some embodiments, the composition can be added with wash oil or tempered water.

[0114] After the composition is introduced into the process equipment, it can be observed that the treated process equipment has less deposition on the equipment compared to the process equipment without the composition. The reduction or inhibition of scaling can be evaluated by any known method or test. In some embodiments, the reduction or inhibition of scaling can be obtained by measuring the time required for gelation of samples with and without the anti-scalant composition. For more details, see the experimental section.

[0115] The following illustrative, non-limiting examples are provided.Examples 1 to 5, 7 to 10, and 12 to 14 detail the preparation of experimental composition components or show formulations for comparative purposes.

[0116] The following abbreviations are used with reference to the following examples and general disclosure: 1,4-naphthoquinone (1,4-NQ), 1,2-naphthoquinone (1,2-NQ), hydroxylamine (HA), N,N-diethylhydroxylamine (DEHA), piperidinol (Pipol), N-isopropylhydroxylamine (IPHA), N,N-bis(2-hydroxypropylhydroxylamine (HPHA), N,N-bis(2-hydroxy-2-phenylethyl)hydroxylamine (BHPhEHA), styrene, butadiene (BD), isoprene, methyl methacrylate (MMA), dibenzylhydroxylamine (DBzHA), 4-hydroxy-2,2,6,6-trimethylpiperidinium oxide (HTMPO), 2,4-dinitro-6-sec-butylphenol (DNBP), 7-phenylmethylquinone (QMPh); comparative example (CE).

[0117] Example 1: Styrene polymerization treated with 400 ppm DEHA (CE)

[0118] 200 g of a styrene solution with 400 ppm DEHA was prepared. The 4-tert-butylcatechol stabilizer was removed from the styrene solution just before the treatment composition was added. An alumina column was used to remove the stabilizer. The reaction mixture was charged into a 1 L three-necked round bottom flask. A magnetic follower was added to the flask, after which a water-cooled condenser and a thermocouple were fixed to two of the three necks. In order to remove dissolved oxygen and exclude atmospheric oxygen from the flask, a stream of nitrogen was passed through the reaction mixture through a gas line in the third neck of the reaction flask. The loaded flask was placed in a heating block that had been preheated to 115°C. The start of the kinetic study was designated as the point at which the temperature of the reaction solution reached 115°C. At this point, a sample was taken from the reaction mixture, diluted with toluene, and the concentration of the polymer was determined by a proprietary method. After 20 minutes, and every 20 minutes thereafter, a sample was taken from the flask and the amount of polymer was determined as described above. The results are shown in Tables 1 and Figure 1 middle.

[0119] Example 2: Polymerization of Styrene Treated with 400 ppm 1,4-NQ (CE)

[0120] A solution of 200 g of fresh clean styrene (with 400 ppm 1,4-naphthoquinone) was prepared. This solution was used to determine the effectiveness of 1,4-naphthoquinone as an anti-polymerization agent using the procedure in Example 1. The results are shown in Tables 1 and Figure 1 middle.

[0121] Example 3: Polymerization of Styrene Treated with 200 ppm DEHA and 200 ppm 1,4-NQ

[0122] Using the procedure of Example 1, a 200 g styrene solution (with 200 ppm DEHA and 200 ppm 1,4-naphthoquinone) was prepared to determine the performance of the two anti-polymerization agents used in combination with each other. The results are shown in Tables 1 and Figure 1Using the combination of 1,4-NQ and DEHA, the inhibition of styrene polymerization was greater than that expected given the results obtained when 1,4-NQ and DEHA were each used at the same total concentration. For comparison purposes, the "expected" anti-polymerization activity level at the 100 minute time point and based on the individual results (without testing the combination of 1,4-NQ and DEHA of the present invention) would be 4.195 ((3.45+4.94) / 2)% (w / w) polymer. However, the combination of 1,4-NQ and DEHA of the present invention (each used at 200 ppm) showed a polymerization level of 0.58% ((w / w) polymer) at 100 minutes, which is a significant and unexpected reduction in polymerization compared to the predicted value of 4.195. This polymerization level of 0.58 is approximately 86% lower than the expected average of 4.195.

[0123] Example 4: Polymerization of Styrene Treated with 400 ppm DNBP (CE)

[0124] A composition of 200 g of fresh clean styrene and 400 ppm DNBP was prepared and tested for anti-aggregation agent kinetics according to the procedure of Example 1. The results are shown in Tables 1 and Figure 1 middle.

[0125] Table 1. Polystyrene concentrations (w / w %) from a study of styrene polymerization kinetics at 115°C anaerobic conditions. Styrene reaction solution with 1,4-NQ, DEHA, unexpected (e.g., synergistic) combinations of DEHA and 1,4-NQ, and for comparative Comparative DNBP treatment.

[0126]

[0127] Example 5: Polymerization of Styrene Treated with 400 ppm Piperidinol (CE)

[0128] A solution of 200 g of fresh clean styrene and 400 ppm piperidinol was prepared and tested for anti-polymerization agent reaction kinetics using the procedure in Example 1. The results are shown in Tables 2 and Figure 2 middle.

[0129] Example 6 Polymerization of Styrene Treated with 200 ppm Piperidinol and 200 ppm 1,4-NQ

[0130] A solution of 200 g of styrene with 200 ppm piperidinol and 200 ppm 1,4-NQ was prepared, and the performance of the two anti-polymerization agents used in combination was determined according to the procedure in Example 1. The results are shown in Tables 2 and Figure 2 Using the combination of 1,4-NQ and piperidinol, the inhibition of styrene polymerization was greater than would be expected given the results obtained when 1,4-NQ and piperidinol were used individually at the same total concentrations.

[0131] Table 2. According to 115 ℃ Polystyrene concentration (w / w%) for kinetic studies under anaerobic conditions. Solutions were treated with 1,4-NQ, piperidinol, and an unexpected (eg, synergistic) combination of 1,4-NQ and piperidinol. For comparison, Use DNBP.

[0132]

[0133] Example 7: Polymerization of Styrene Treated with 400 ppm DBzHA (CE)

[0134] The anti-polymerization agent reaction kinetics of 200 g of fresh clean styrene solution (containing DBzHA anti-polymerization agent metered into the solution at a concentration of 400 ppm) were tested using the procedure in Example 1. The results are shown in Tables 3 and Figure 3 middle.

[0135] Example 8: Polymerization of Styrene Treated with 200 ppm DBzHA and 200 ppm 1,4-NQ

[0136] A solution of 200 g of styrene, 200 ppm DBzHA and 200 ppm 1,4-NQ was prepared, and the performance of the two anti-polymerization agents used in combination was measured according to the procedure in Example 1. The results are shown in Tables 3 and Figure 3 Using the combination of 1,4-NQ and DBzHA, the inhibition of styrene polymerization was greater than expected considering the results obtained when 1,4-NQ and DBzHA were used individually at the same total concentrations.

[0137] Table 3. Polystyrene concentration (w / w %) during styrene polymerization kinetics study at 115°C under anaerobic conditions. The styrene reaction solution was treated with 1,4-NQ, DBzHA, and an unexpected (eg, synergistic) combination of DBzHA and 1,4-NQ. DNBP was used for comparison.

[0138]

Claims

1. A method for reducing polymer formation in a composition containing monomers, the method comprising: include: To a composition comprising a polymerizable monomer or a compound capable of forming a polymerizable monomer component is added: Naphthoquinone, and Hydroxylamine of the formula: Formula I: HO-NR 1 R 3 , where R 1 and R 2 At least one or both of are carbon-containing groups having 1 to 12 carbon atoms, optionally substituted with one or more hydroxyl groups, wherein if R 1 or R 2 is not a carbon-containing group, then -H; or Formula II: Where X is -(CHR 5 ) w -, where R 5 Selected from -H, R 3 and R 4 , R 3 is selected from -H and alkyl, and R 4 is selected from -H and -OH, y is 0 or an integer in the range of 1 to 3, z is 0 or an integer in the range of 1 to 3, and w is an integer in the range of 1 to 4, wherein the naphthoquinone and the hydroxylamine reduce polymer formation in the composition.

2. The method according to claim 1, wherein R 1 is selected from (i) a C1-C12 alkyl group, (ii) a C1-C8 alkyl group, or (iii) a C1-C6 alkyl group, wherein (i) to (iii) are linear, branched or cyclic alkyl groups, or a combination thereof; and R 2 Selected from (iv) -H and C1-C12 alkyl groups, (v) -H and C1-C8 alkyl groups, or (vi) -H and C1-C6 alkyl groups, wherein the alkyl groups in (iv) to (vi) are linear, branched or cyclic, or a combination thereof, and wherein any one or more of the alkyl groups in (i) to (vi) are optionally substituted with one or more hydroxyl groups.

3. The method according to claim 2, wherein R 1 is selected from (A) methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, cyclohexyl, 1-methylbutyl, 2-methylbutyl and 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl or 2,2-dimethylpropyl, 1-ethyl-propyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl or 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl or 3,3-dimethylbutyl, 1-ethylbutyl or 2-ethylbutyl, 1-ethyl-1-methylpropyl and 1,1,2-trimethylpropyl or 1,2,2-trimethylpropyl and methylcyclopentyl, and R 2 Selected from (A) and -H, wherein either of (A) is optionally substituted with one or more hydroxy groups.

4. The method according to claim 3, wherein the compound of formula I is selected from N,N-dimethylhydroxylamine, N-methyl-N-ethylhydroxylamine, N-methyl-N-propylhydroxylamine, N-methyl-N-isopropylhydroxylamine, N-methyl-N-propylhydroxylamine, N-methyl-N-butylhydroxylamine, N-methyl-N-isobutylhydroxylamine, N-methyl-N-tert-butylhydroxylamine, N,N-diethylhydroxylamine, N-ethyl-N-propylhydroxylamine, N-ethyl-N-isopropylhydroxylamine, Propylhydroxylamine, N-ethyl-N-propylhydroxylamine, N-ethyl-N-butylhydroxylamine, N-ethyl-N-isobutylhydroxylamine, N-ethyl-N-tert-butylhydroxylamine, N,N-dipropylhydroxylamine, N,N-diisopropylhydroxylamine, N-propyl-N-butylhydroxylamine, N-isopropyl-N-butylhydroxylamine, N-propyl-N-isobutylhydroxylamine, N-propyl-N-tert-butylhydroxylamine, N-isopropyl-N-isobutylhydroxylamine and N-isopropyl-N-tert-butylhydroxylamine.

5. The method according to claim 3, wherein the compound of formula I is selected from N-methylhydroxylamine, N-ethylhydroxylamine, N-propylhydroxylamine, N-isopropylhydroxylamine, N-butylhydroxylamine, N-isobutylhydroxylamine, N-tert-butylhydroxylamine, N-sec-butylhydroxylamine, N-pentylhydroxylamine, N-cyclopentylhydroxylamine, N-isopentylhydroxylamine, N-neopentylhydroxylamine, N-hexylhydroxylamine, N-cyclohexylhydroxylamine, N-1-methylbutylhydroxylamine, N-2-methylbutylhydroxylamine and N-3-methylbutylhydroxylamine, N-1,1-dimethylpropylhydroxylamine, N-1,2-dimethylpropylhydroxylamine or N-2,2-dimethylpropylhydroxylamine, N- 1-ethyl-propylhydroxylamine, 1-methylpentylhydroxylamine, 2-methylpentylhydroxylamine, 3-methylpentylhydroxylamine or 4-methylpentylhydroxylamine, N-1,1-dimethylbutylhydroxylamine, N-1,2-dimethylbutylhydroxylamine, N-1,3-dimethylbutylhydroxylamine, N-2,2-dimethylbutylhydroxylamine, N-2,3-dimethylbutylhydroxylamine or N-3,3-dimethylbutylhydroxylamine, N-1-ethylbutylhydroxylamine or N-2-ethylbutylhydroxylamine, N-1-ethyl-1-methyl-propylhydroxylamine and N-1,1,2-trimethylpropylhydroxylamine or N-1,2,2-trimethylpropylhydroxylamine and N-methylcyclopentylhydroxylamine.

6. The method according to claim 3, wherein the compound of formula I is selected from N-hydroxymethylhydroxylamine, N-1-hydroxyethylhydroxylamine or N-2-hydroxyethylhydroxylamine, N-1-hydroxypropylhydroxylamine, N-2-hydroxypropylhydroxylamine or N-3-hydroxypropylhydroxylamine, N-1-hydroxypropylhydroxylamine or N-2-hydroxypropylhydroxylamine, N-1-hydroxybutylhydroxylamine, N-2-hydroxybutylhydroxylamine, N-3-hydroxybutylhydroxylamine or N-4-hydroxybutylhydroxylamine, N-1-hydroxyisobutylhydroxylamine, N-2-hydroxyisobutylhydroxylamine or N-3-hydroxyisobutylhydroxylamine, N-1-hydroxysec-butylhydroxylamine, N-2-hydroxysec-butylhydroxylamine or N-3-hydroxysec-butylhydroxylamine, N-2-hydroxy-tert-butylhydroxylamine and N-1-N-hydroxypentylhydroxylamine, N-2-N-hydroxypentylhydroxylamine, N-3-N-hydroxypentylhydroxylamine Amine, N-4-N-hydroxypentylhydroxylamine or N-5-N-hydroxypentylhydroxylamine; or N,N-bis(hydroxymethyl)hydroxylamine, N,N-bis(1-hydroxyethyl or 2-hydroxyethyl)hydroxylamine, N,N-bis(1-hydroxypropyl, 2-hydroxypropyl or 3-hydroxypropyl)hydroxylamine, N,N-bis(1-hydroxypropyl or 2-hydroxypropyl)hydroxylamine, N,N-bis(1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl or 4- N,N-bis(1-hydroxyisobutyl, 2-hydroxyisobutyl or 3-hydroxyisobutyl)hydroxylamine, N,N-bis(1-hydroxysec-butyl, 2-hydroxysec-butyl or 3-hydroxysec-butyl)hydroxylamine, N,N-bis(2-hydroxy-tert-butyl)hydroxylamine and N,N-bis(1-N-hydroxypentyl, 2-N-hydroxypentyl, 3-N-hydroxypentyl, 4-N-hydroxypentyl or 5-N-hydroxypentyl)hydroxylamine.

7. The method according to claim 1, wherein R as the carbon-containing group having 1 to 12 carbon atoms 1 and R 2 One or both of contain an aryl group, optionally wherein R 1 and R 2 One or both of them have the following formula: Where R 6 are independently selected from -H, -OH and alkyl, wherein v is an integer in the range of 1 to 6, R 7 are independently selected from -H, -OH and alkyl, wherein q is an integer in the range of 1 to 5.

8. The method according to claim 7, wherein the formula is: R 6 are independently selected from -H and -OH, v is an integer in the range of 1 to 4, R 7 is -H and q is 5, wherein the compound optionally Selected from benzylhydroxylamine, N-phenethyl-hydroxylamine, N-(3-phenyl-propyl)-hydroxylamine, N-(4-phenyl-butyl)-hydroxylamine, N-(5-phenyl-pentyl)-hydroxylamine, N-(6-hexyl-propyl)-hydroxylamine, N-(3-phenyl-2-methyl-propyl)-hydroxylamine and N-(4-phenyl-3-methyl-butyl)-hydroxylamine; Selected from dibenzylhydroxylamine, N,N-bis(phenylethyl)hydroxylamine, N,N-bis(3-phenylpropyl)hydroxylamine, N,N-bis(4-phenyl-butyl)-hydroxylamine, N,N-bis(5-phenyl-pentyl)-hydroxylamine, N,N-bis(6-hexyl-propyl)-hydroxylamine, N,N-bis(3-phenyl-2-methyl-propyl)-hydroxylamine and N,N-bis(4-phenyl-3-methyl-butyl)-hydroxylamine; is selected from N-(2-phenyl-1-hydroxy-ethyl)hydroxylamine, N-(3-phenyl-2-hydroxy-propyl)-hydroxylamine, N-(4-phenyl-2-hydroxy-butyl)-hydroxylamine, N-(5-phenyl-2-hydroxy-pentyl)-hydroxylamine, N-(6-hexyl 2-hydroxy-propyl)-hydroxylamine, Selected from N,N-bis(2-phenyl-1-hydroxy-ethyl)hydroxylamine, N,N-bis(3-phenyl-2-hydroxy-propyl)-hydroxylamine, N,N-bis(4-phenyl-2-hydroxy-butyl)-hydroxylamine, N,N-bis(5-phenyl-2-hydroxy-pentyl)-hydroxylamine and N,N-bis(6-hexyl 2-hydroxy-propyl)-hydroxylamine.

9. The method according to any one of the preceding claims, wherein the naphthoquinone is 1,4-naphthoquinone, 1,3-naphthoquinone or 1,2-naphthoquinone.

10. The method according to any one of the preceding claims, wherein the naphthoquinone is an aminated naphthoquinone anti-polymerization agent selected from the group consisting of 2-amino-1,4-naphthoquinone, 2,3-diamino-1,4-naphthoquinone, 2-amino-1,3-naphthoquinone, 4-amino-1,3-naphthoquinone, 2,4-diamino-1,3-naphthoquinone, 3-amino-1,2-naphthoquinone, 4-amino-1,2-naphthoquinone and 3,4-diamino-1,3-naphthoquinone.

11. The method of any one of the preceding claims, wherein the polymerizable monomer comprises a vinyl or ethylenically unsaturated group.

12. The method of claim 11, wherein the polymerizable monomer is selected from the group consisting of acrylic acid, acrylonitrile, alkylated styrene, butadiene, chloroprene, divinylbenzene, ethyl acrylate, ethyl methacrylate, isoprene, methacrylic acid, methyl methacrylate, methyl acrylate, α-methylstyrene, methacrylonitrile, styrene, styrene sulfonic acid, vinyltoluene, and vinylpyridine.

13. The method according to any one of the preceding claims, wherein the composition comprises one or more non-polymerizable hydrocarbons.

14. The method according to any one of the preceding claims, wherein the naphthoquinone is present in the composition in an amount ranging from 50 ppm to 500 ppm and the hydroxylamine is present in the composition in an amount ranging from 50 ppm to 500 ppm, optionally wherein the naphthoquinone is present in the composition in an amount ranging from 75 ppm to 400 ppm and the hydroxylamine is present in the composition in an amount ranging from 75 ppm to 400 ppm, optionally wherein the naphthoquinone is present in the composition in an amount ranging from 100 ppm to 300 ppm and the hydroxylamine is present in the composition in an amount ranging from 100 ppm to 300 ppm, optionally wherein the naphthoquinone is present in the composition in an amount ranging from 150 ppm to 250 ppm and the hydroxylamine is present in the composition in an amount ranging from 150 ppm to 250 ppm.

15. A method according to any one of the preceding claims, wherein the adding is performed during purification or processing of one or more hydrocarbon components of the composition.

16. The method of claim 15, wherein processing of the one or more hydrocarbons comprises a distillation step.

17. A method according to any preceding claim, carried out prior to storage or transport of the composition.

18. A method according to any one of the preceding claims, wherein the naphthoquinone is used at a first concentration and the hydroxylamine is used at a second concentration, wherein the first concentration and the second concentration together are a total concentration, and the combination of the naphthoquinone and the hydroxylamine together provides a level of polymer formation that is lower than the level of polymer formation observed when the naphthoquinone and the hydroxylamine are used individually at the total concentration, or is an average of the levels of polymer formation when the naphthoquinone and the hydroxylamine are used individually at the total concentration.

19. The method of claim 18, wherein the combination of the hydroxylamine and the naphthoquinone provides a reduction in polymerization of 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more, such as up to about 90% or more, or a % reduction within a range of any of these values, compared to the average or compared to naphthoquinone and hydroxylamine used individually at the total concentration.

20. An additive composition for inhibiting monomer polymerization, the composition comprising: Naphthoquinone, and Hydroxylamine of the formula: Formula I: HO-NR 1 R 2 , where R 1 and R 2 At least one or both of are carbon-containing groups having 1 to 12 carbon atoms, optionally substituted with one or more hydroxyl groups, wherein if R 1 or R 2 is not a carbon-containing group, then -H; or Formula II: Where X is -(CHR 5 ) w -, where R 5 Selected from -H, R 3 and R 4 , R 3 is selected from -H and alkyl, and R 4 is selected from -H and -OH, y is 0 or an integer in the range of 1 to 3, z is 0 or an integer in the range of 1 to 3, and w is an integer in the range of 1 to 4.

21. The composition of claim 20, further comprising an organic solvent.

22. The composition according to claim 21, in, The amount of naphthoquinone is in the range of 5% to 45% by weight; The amount of hydroxylamine is in the range of 5% to 45% by weight; and The amount of the organic solvent is in the range of 10 to 90% by weight.

23. The composition according to claim 22, in, The amount of naphthoquinone is in the range of 15% to 35% by weight; The amount of hydroxylamine is in the range of 15% to 35% by weight; and The amount of the organic solvent is in the range of 30 to 70% by weight.

24. Use of a composition according to any one of claims 20 to 23 for reducing polymer formation in a composition.

25. Use of a composition according to any one of claims 20 to 23 in a hydrocarbon refining or hydrocarbon purification process.

26. Use of a composition according to any one of claims 20 to 23 for the storage or transportation of hydrocarbon compositions.

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