Phosphorus-free, oil-soluble molybdenum complex as a high-temperature scale inhibitor

Abstract

Sulfur-containing molybdenum complexes are disclosed for use in compositions and methods for inhibiting or reducing the deposition of foulants on equipment.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 058,023, filed on July 29, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to an antifouling agent composition. Background Art

[0004] The processes involved in oil and gas production, oil, gas and petroleum refining, and the petrochemical industry, such as coking, visbreaking, reforming, hydroreforming, absorption, isomerization, extraction, cracking, fractionation, hydrotreating, and desalination, expose hydrocarbon streams to relatively elevated temperatures. These temperatures are most commonly achieved through furnace heaters and heat exchangers, where hydrocarbon feeds, products, and intermediates come into close contact with heated surfaces. These conditions are known to promote the formation of deposits, which can foul various systems and processes. For example, foulant deposits can limit refining capacity and flow rates. Fouling in furnace heaters can cause heat transfer losses, hot spots throughout the pipeline, and metallurgical distortion problems. Fouling in heat exchangers can result in gradual efficiency losses, heat transfer losses, and pressure drops. These problems can reduce production throughput due to the deposition of material on their internal surfaces. Consequently, process units must be regularly shut down to remove the deposits or replaced.

[0005] Coke is a typical fouling material, which is produced as a direct by-product of polymerization and condensation reactions from the lightest to the heaviest fractions (mellow asphaltenes, asphaltenes and coke). Fouling is generally attributed to the presence of unstable components, such as thermally generated radicals, oxygenated derivatives of hydrocarbons, inorganic impurities present in the hydrocarbon fractions, the presence of olefinically unsaturated hydrocarbons or their polymeric derivatives, etc. Therefore, almost all crude oils and their fractions, as well as process fractions prepared therefrom, contain reactive hydrocarbon components. In addition, almost all crude oils contain small amounts of dissolved oxygen, sulfur and metals in free and / or combined form. If chemical and / or thermal treatments are involved, the reactive parts in the hydrocarbon matrix may trigger polymerization reactions.

[0006] Fouling of heat exchangers and equipment such as furnaces, piping, reboilers, condensers, compressors, and auxiliary equipment is costly due to lost production time and increased man-hours required for disassembly, cleaning, and reassembly of process equipment components. Summary of the Invention

[0007] Compositions and methods are disclosed for inhibiting or reducing foulant deposition, thereby improving system energy efficiency and preventing product quality problems.

[0008] In one aspect of the present application, a method of inhibiting foulant deposition is disclosed, the method comprising:

[0009] A composition comprising a sulfur-containing molybdenum complex having a general formula selected from Formula I or II is introduced into process equipment or a fluid in contact with process equipment:

[0010] Mo2-(SR) n Formula I

[0011] wherein R represents an oxygen-, nitrogen- or carbon-containing compound, such as an alcohol, an alkyl group, an alkenyl group, an amide, an amine group or an aryl group; and n is 4-10.

[0012]

[0013] R and R' each represent an oxygen-, nitrogen- or carbon-containing compound, such as an alcohol, alkyl, alkenyl, amide, amine or aryl group; and X represents oxygen or sulfur and may be the same or different, but wherein at least one X in the formula is sulfur.

[0014] In another aspect, a composition comprising a sulfur-containing molybdenum complex is disclosed for inhibiting the deposition of foulants in contact with process equipment.

[0015] Mo2-(SR) n Formula I

[0016] wherein R represents an oxygen-, nitrogen- or carbon-containing compound, such as an alcohol, an alkyl group, an alkenyl group, an amide, an amine group or an aryl group; and n is 4-10.

[0017]

[0018] R and R' each represent an oxygen-, nitrogen- or carbon-containing compound, such as an alcohol, alkyl, alkenyl, amide, amine or aryl group; and X represents oxygen or sulfur and may be the same or different, but wherein at least one X in the formula is sulfur.

[0019] In yet another aspect is treated process equipment, comprising: process equipment comprising a metal surface; and a fluid source comprising a sulfur-containing molybdenum complex as described in Formulas I, III, and IV, wherein at least a portion of the metal surface is in contact with the fluid source.

[0020] Sulfur-containing molybdenum complexes are used to inhibit the deposition of organic and inorganic materials on equipment during operation of manufacturing and / or chemical processes, which deposits may be undesirable and include, but are not limited to, asphaltenes and coke. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a graphical representation of surface coke deposition in the presence of Test Complex A compared to Comparative Complex 1 and Comparative Complex 2. DETAILED DESCRIPTION

[0022] Although the present disclosure provides references to 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 application. Reference to various embodiments does not limit the scope of the claims appended hereto. Furthermore, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments of the appended claims.

[0023] The publications, patents, and patent documents mentioned in this application are incorporated herein by reference in their entirety, as if individually incorporated by reference. In the event of any inconsistency between this application and a document incorporated by reference, the present application controls and the incorporated document supplements this application.

[0024] As used herein, the term "antifoulant" refers to a complex that prevents, retards, mitigates, reduces, controls and / or delays the deposition of organic and inorganic materials, such as polymers, prepolymers, oligomers and / or other materials, on "process equipment." The term will be understood to refer to the antifoulant itself or to the antifoulant in a composition that may include other antifoulants or compounds or solvents, as determined by the context.

[0025] As used herein, the term "foulants" means organic and inorganic materials deposited on equipment during the operation of a manufacturing and / or petroleum and / or chemical process, which foulants may be unwanted and may be detrimental to the cost and / or efficiency of the process and include, but are not limited to, asphaltenes and coke.

[0026] As used herein, the term "hydrocarbon processing" means processes performed on hydrocarbon materials including, but not limited to, refining, storing, transporting, fractionating, or otherwise affecting the hydrocarbon materials.

[0027] As used herein, the terms "inhibits," "inhibiting," or grammatical equivalents thereof, refer to preventing, retarding, mitigating, reducing, controlling, and / or delaying the deposition of foulants.

[0028] As used herein, the term "passivate" means preventing a reaction between two materials when the two materials are used together by coating at least one of the two materials to an extent that their reactivity relative to each other is substantially reduced.

[0029] As used herein, the term "process equipment" means equipment used to refine, store, transport, fractionate, or otherwise process materials, including but not limited to heaters, heat exchangers, test tubes, piping, heat transfer vessels, process vessels, storage tanks, compressors, fans, impellers, pumps, valves, intercoolers, sensors, etc., which are associated with the process and may be subject to the deposition of foulants. The term also includes groups of interconnected components, such as a gas compressor in an ethylene cracking process.

[0030] As used herein, the terms "optional" or "optionally" mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0031] As used herein, the term "about" in describing modifications, such as amounts of ingredients in compositions, concentrations, volumes, process temperatures, process times, yields, flow rates, pressures, and the like, and ranges thereof, employed in the embodiments of the present disclosure, refers to variations in the numerical amount that may occur, for example, by typical measurement and processing procedures used to prepare compounds, compositions, concentrates, or formulations for use; by inadvertent errors in these procedures; by differences in the manufacture, source, or purity of starting materials or ingredients used to perform the methods, and similar approximate considerations.

[0032] The term "about" also encompasses amounts that vary from a specific starting concentration or mixture due to aging of the formulation, and amounts that vary from a specific starting concentration or mixture due to mixing or processing of the formulation. Where modified by the term "about," the appended claims include equivalents to these amounts. Furthermore, where "about" is used to describe any range of values, such as "about 1 to 5," the recitation is intended to mean "1 to 5" and "about 1 to about 5" and "1 to about 5" as well as "about 1 to 5," unless the context clearly dictates otherwise.

[0033] As used herein, the word "substantially" employed in describing embodiments of the present disclosure to modify, for example, the type or amount of an ingredient in a composition, a characteristic, a measurable amount, a method, a position, a value, or a range, refers to a change that does not affect the overall recounted composition, characteristic, amount, method, position, value, or range in a manner that invalidates the intended composition, characteristic, amount, method, position, value, or range. Examples of intended characteristics, by way of non-limiting example only, include flexibility, partition coefficient, rate, solubility, temperature, and the like; and intended values ​​include thickness, yield, weight, concentration, and the like. Effects on a process modified by "substantially" include effects caused by changes in the type or amount or amount of materials used in the process, changes in machine settings, effects on environmental conditions of the process, and the like, where the manner or degree of the effects does not invalidate one or more intended characteristics or results; and similar proximity considerations. The appended claims wherein modified by the term "substantially" include equivalents of these types and amounts of materials.

[0034] As used herein, any recited range of values ​​contemplates all values ​​within the recited range and should be interpreted as supporting claims reciting any sub-range having endpoints with real values ​​within the recited range. By way of hypothetical illustrative example, disclosure of a range of 1 to 5 in this specification should be considered supporting claims for any of the following ranges: 1-5; 1-4; 1-3; 1-2; 2-5; 2-4; 2-3; 3-5; 3-4; and 4-5, and any range therebetween.

[0035] Compositions and methods for inhibiting the deposition of foulants in equipment and systems, such as those used in petroleum or hydrocarbon processing, are described. The compositions include at least one sulfur-containing molybdenum complex. The sulfur-containing molybdenum complex contains at least one molybdenum center coordinated to at least one sulfur and may include oxygen and oxygen-, nitrogen-, or carbon-containing ligands, including thiolates, sulfides, thiocarbamates, thiocarbonates, thioacids, or polymers thereof, and combinations thereof. The compositions and methods inhibit fouling by acting as an antifoulant, passivating the surface, or both.

[0036] In some embodiments, the sulfur-containing molybdenum complex has the general formula of Formula I or Formula II.

[0037] Mo2-(SR) n Formula I

[0038] wherein Mo is a molybdenum complex, S is sulfur, R represents an oxygen-, nitrogen- or carbon-containing ligand, such as an alcohol, an alkyl, an alkenyl, an amide, an amine or an aryl; and n is 4-10.

[0039]

[0040] wherein R and R' each represent an oxygen-, nitrogen-, or carbon-containing ligand, such as an alcohol, alkyl, alkenyl, amide, amine, or aryl, and R and R' may be the same or different; and X represents oxygen or sulfur and may be the same or different, but wherein at least one X in the formula is sulfur.

[0041] In some embodiments, R or R' represents an alkyl group (straight chain, branched or cyclic) with or without saturation or heteroatoms, or both; a thiolate, a sulfide, a thiocarbamate, a thiocarbonate, a thioacid, an aromatic ring with or without substituents, an organic polysulfide, or an inorganic polysulfide (e.g., S2 to S8).

[0042] In some embodiments, R and R' are each an alkyl group having 2 to 30 carbon atoms; 5 to 20 carbon atoms; 5 to 15 carbon atoms; 5 to 10 carbon atoms, or an aryl group (including alkaryl). In some embodiments, the above carbon number is characterized by one or more hydroxyl groups (e.g., alkyl alcohols), acids, or esters thereof. In some embodiments, the alkyl group is ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl, cyclohexyl, phenyl, naphthyl, tolyl, xylyl, benzyl, and phenethyl. These alkyl groups can be primary, secondary, or tertiary alkyl groups and can be straight or branched. In some embodiments, (alkyl) aryl groups include phenyl, tolyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, and dodecylphenyl, all of which can be primary, secondary, or tertiary alkyl groups and can be straight or branched. Furthermore, (alkyl)aryl includes all positional isomers, wherein the aryl group may have an alkyl substituent at any position. In some embodiments, the (alkyl)aryl group as described above is composed of carbon and hydrogen, and may include heteroatoms such as nitrogen, oxygen, and sulfur.

[0043] In some embodiments, the alcohol group can be a monosubstituted alcohol, a diol, or a bis-ol, or a polyol. In some embodiments, the alcohol is six to ten carbon atoms.

[0044] In some embodiments, the amino group may be a monoamine, a diamine, or a polyamine. In some embodiments, the amine is a dialkylamine having the formula HNR5R6, wherein R5 and R6 are each selected from a straight or branched chain containing 2 to 24 carbon atoms, or 4-13; 8 to 13; or 10 to 20 carbon atoms. R5 may be the same as or different from R6. In some embodiments, R5 and R6 may be aryl groups including (alkyl)aryl groups. In some embodiments, the alkyl group is ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. These alkyl groups may be primary, secondary, or tertiary and may be straight or branched. The alkyl group may be straight or branched, and the alkyl group may be bonded to any position of the phenyl group and mixtures thereof.

[0045] Other molybdenum complexes are sulfur-containing molybdenum dithiolates, molybdenum dithioesters or molybdenum thio-terminated amide complexes.

[0046] In some embodiments, R and R' can be 1-4 rings or aromatic groups.

[0047] In some embodiments, the sulfur-containing molybdenum complex has the following general formula III:

[0048]

[0049] wherein R is as described above. In some embodiments, R is an alkyl group (straight chain, branched chain, or cyclic) with or without saturation or heteroatoms, or both; a thiolate, a sulfide, a thiocarbamate, a thiocarbonate, a thioacid, an aromatic ring with or without substituents, an organic polysulfide, an inorganic polysulfide; and n is 2-10 or 2-6.

[0050] In some embodiments, R in the sulfur-containing molybdenum is a sulfur-containing phenol. In some embodiments, the sulfur-containing phenol is ethylhexylphenol; 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), bis(3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, and 2,2'-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate].

[0051] In some embodiments, R and R' are each an organic polysulfide or an inorganic polysulfide. In some embodiments, the inorganic polysulfide has 2-10, 2-8, or 3-7 sulfur atoms. In some embodiments, the organic polysulfide has the general formula IV:

[0052] R 2 -S x -R 3 Formula IV

[0053] where R 2 and R 3 Each is as described above for R and R'. In some embodiments, R 2 and R 3 Each is an alkyl group (aliphatic, acyclic, aromatic and heterocyclic groups) and R 2 and R 3 may be the same or different; and x is in the range of 2 to 8.

[0054] In some embodiments, the polysulfide is di-(2-ethylhexyl) polysulfide, dibenzyl polysulfide, di-tert-nonyl polysulfide, dilauryl polysulfide, di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl polysulfide, and dicyclohexyl polysulfide.

[0055] In other embodiments, R, R', R 2 and R 3 methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, cyclohexyl, phenyl, naphthyl, tolyl, xylyl, benzyl, phenethyl, ethylhexyl, which are thiolates, thiocarbamates, thiocarbonates, thioacids thereof, and mixtures thereof.

[0056] In some embodiments, the sulfur-containing molybdenum complex is shown below.

[0057]

[0058] wherein arcs represent alkyl chains (straight, branched, and cyclic) with or without saturation or heteroatoms, or both; dithiocarbamates, dithiocarbonates, dithioacids, aromatic rings with or without substituents, organic polysulfides, or inorganic polysulfides.

[0059] In some embodiments, R, R', R 2 and R 3 The thiolates, thiocarbamates, thiocarbonates, thioacids, dithiolates, dithiocarbamates, dithiocarbonates, dithioacids, polymers thereof, and mixtures thereof.

[0060] In some embodiments, R, R', R 2 and R 3is diethyl dithiocarbamate, dipropyl dithiocarbamate, dibutyl dithiocarbamate, dipentyl dithiocarbamate, dihexyl dithiocarbamate, dioctyl dithiocarbamate, didecyl dithiocarbamate, dilauryl dithiocarbamate, di(butylphenyl) dithiocarbamate, di(nonylphenyl) dithiocarbamate or di(2-ethylhexyl) dithiocarbamate or a mixture thereof.

[0061] In some embodiments, the sulfur-containing molybdenum complex contains no phosphorus, or has little or no phosphorus. Such complexes provide longer life for catalysts used in hydrocarbon processing processes.

[0062] Any method known to those skilled in the art can be used to prepare the sulfur-containing molybdenum complex. For example, the sulfur-containing molybdenum complex can be prepared as described in Tribology International, Vol. 27, No. 6, pp. 379-386 (1994); Tribology International, Vol. 53, pp. 150-158 (2012); and U.S. Pat. No. 3,356,702, all of which are incorporated herein by reference in their entirety.

[0063] For example, molybdenum compounds in various oxidation states (e.g., 2-6) can be used and can be represented by the following composition: molybdic acid, ammonium molybdate, molybdenum salts such as MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide, or similar acidic molybdenum compounds. Acidic molybdenum compounds include molybdic acid, ammonium molybdate, and molybdenum trioxide. Molybdates include molybdenum oxide or molybdenum sulfide. The molybdate is reacted with a sulfur source. For example, sulfur sources include sulfur, hydrogen sulfide, sulfur monochloride, sulfur dichloride, phosphorus pentasulfide, R2Sx (wherein R is a hydrocarbon group, preferably a C1-40 alkyl group, and x is at least 2), inorganic sulfides and polysulfides (e.g., (NH4)2Sx, where x is at least 1), thioacetamide, thiourea, and mercaptans of the formula RSH, where R is as defined above. Similarly, conventional sulfur-containing antioxidants such as wax sulfides and polysulfides, olefins, carboxylic acids, esters, and ester-olefins, and alkylphenols and their metal salts can be used as sulfurizing agents.

[0064] In some embodiments, the composition comprises, consists essentially of, or consists of at least one of the described sulfur-containing molybdenum complexes. The sulfur-containing molybdenum complexes can be formulated as antifoulants or passivating compositions for inhibiting the deposition of foulants (e.g., coke) on metal surfaces of process equipment in contact with hydrocarbon materials (in liquid or gaseous form), where the surface or liquid reaches a temperature of 200° C. to 1500° C. In some embodiments, the composition comprises, consists essentially of, or consists of at least one of the described sulfur-containing molybdenum complexes to inhibit fouling by acting as an antifoulant, passivating the surface, or both.

[0065] In some embodiments, the sulfur-containing molybdenum complex is formulated with a solvent such as water; an alcohol such as methanol, ethanol, isopropanol, n-propanol, n-butanol, isobutanol, sec-butanol, tert-butanol, or a higher alcohol such as benzyl alcohol); a ketone such as acetone or methyl ethyl ketone (2-butanone); acetonitrile; an ester such as ethyl acetate, propyl acetate, and butyl acetate; an ether such as diethyl ether or a higher ether, for example, methyl tert-butyl ether, glycol dimethyl ether, diglycol dimethyl ether, ethylene glycol monobutyl ether, ethylene diglycol ethyl ether, 1,4-dioxane, and related substances; an aromatic such as toluene, xylene, diethylbenzene, naphthalene, and related aromatics or refinery fractions (heavy aromatic naphtha, heavy aromatic distillates, and related substances); an aliphatic such as pentane, hexane, heptane, octane, or refined gasoline.

[0066] In some embodiments, solvents suitable for formulation with molybdenum-containing compositions are aliphatics, such as pentane, hexane, cyclohexane, methylcyclohexane, heptane, decane, dodecane, etc.; and aromatics, such as toluene, xylene, heavy aromatic naphtha, diesel, fatty acid derivatives (acids, esters, amides), etc.

[0067] In some embodiments, the one or more solvents comprise 10 wt% to 99 wt% of the sulfur-containing molybdenum complex; 1-25 wt%; 20-50 wt%; 30-75 wt%; 50-75%; 75-100 wt% of the sulfur-containing molybdenum complex.

[0068] In some embodiments, the sulfur-containing molybdenum complex is provided in pure form (ie, without solvent). In some embodiments, the sulfur-containing molybdenum complex is provided as a concentrate.

[0069] In some embodiments, the sulfur-containing molybdenum complex or a composition containing the same includes other additives, such as one or more asphaltene inhibitors, paraffin inhibitors, scale inhibitors, demulsifiers, water clarifiers, dispersants, demulsifiers, defoamers, or any combination thereof. In some embodiments, the sulfur-containing molybdenum complex further includes one or more solvents or mixtures thereof.

[0070] While the effective amount of the sulfur-containing molybdenum complex used depends on many factors, such as local operating conditions, the hydrocarbon being processed, the temperature and other characteristics of the process, in some embodiments, the sulfur-containing molybdenum complex or the sulfur-containing molybdenum complex in the composition is used in the following amounts, based on the weight or volume of the sulfur-containing molybdenum complex in the fluid source: about 0.1 ppm to 10,000 ppm; 0.1 ppm to 3,000 ppm; about 100 ppm to 1500 ppm; about 100 ppm to 1000 ppm; about 500 ppm to 3,000 ppm; about 750 ppm to 3,000 ppm; about 2,000 ppm to 5,000 ppm; ,000ppm; about 3,000ppm to 5000ppm; 100ppm to 3,000ppm; about 1ppm to 1000ppm; about 1ppm to 3,000ppm; about 10ppm to 50ppm; about 50ppm to 100ppm; 100pp to 800ppm; 150ppm to 550ppm; about 1ppm to 250ppm; about 1ppm to 50ppm; about 1ppm to 25ppm; about 1ppm to 5ppm; about 3ppm to 25ppm; about 0.1ppm to 5ppm; or about 0.1ppm to 1ppm.

[0071] The sulfur-containing molybdenum complex can be added by any suitable method. For example, the sulfur-containing molybdenum complex can be added neat or as a dilute solution. In some embodiments, the sulfur-containing molybdenum complex can be introduced as a solution, emulsion, or dispersion, sprayed, dripped, poured, or injected into a desired opening within the system or onto process equipment or process condensate. In some embodiments, the sulfur-containing molybdenum complex can be added with wash oil or ambient temperature water.

[0072] Sulfur-containing molybdenum complexes can be added to process equipment continuously or intermittently as needed to inhibit scaling. In some embodiments, the molybdenum-containing anti-scaling complex is introduced during or after a decoking or cleaning process such as online stripping, mechanical pigging, or steam / air combustion processes. In some embodiments, the molybdenum-containing anti-scaling complex is introduced during a warming process (i.e., returning the unit to process temperature after shutting down and / or cleaning processes). In some embodiments, when the equipment is shut down and decoked and cleaned, a sulfur-containing molybdenum complex is introduced to passivate the surface. In other embodiments, the sulfur-containing molybdenum complex is added and passivation can occur without shutting down the equipment. Any method known in the art can be used to passivate the surface, such as U.S. Patent No. 9,845,437, which is incorporated herein by reference in its entirety.

[0073] In some embodiments, the sulfur-containing molybdenum complex can be pumped or injected into the system in a continuous or intermittent manner to reduce scaling in the process unit. The injection point can be at any or all stages of the process unit.

[0074] The sulfur-containing molybdenum complexes are used on any suitable process equipment, such as process equipment used in the production and refining of oil and gas. In some embodiments, the process equipment includes a thermal conversion unit, a heat exchanger, a visbreaker, a coker, a fired heater, a furnace, a fractionator, or other heat transfer equipment. In some embodiments, the process equipment is a gas compressor. In some embodiments, the process equipment is a coil, a heat exchanger, a transmission line exchanger quencher, a furnace, a separation tower, or a fractionator. The sulfur-containing molybdenum complexes can also be used in other similar applications and used with other equipment. For example, the sulfur-containing molybdenum complexes can be used with any process in which the process equipment will come into contact with unsaturated monomers, such as in an ethylene cracking gas process. Another application is an ethylene and acrylonitrile quench water system. The sulfur-containing molybdenum complexes can be used with ethylene dilution steam generators and acrylonitrile purification systems. Many polymer processes have monomer recovery systems that are subject to fouling and are good target applications for sulfur-containing molybdenum complexes. Water strippers and wastewater strippers used in conjunction with petrochemical processes (such as styrene, butadiene, acrylonitrile and ethylene processes) are potential applications of sulfur-containing molybdenum complexes. In some embodiments, ethylene acid gas scrubbers and butadiene solvent recovery systems are also end-use applications of sulfur-containing molybdenum complexes. Sulfur-containing molybdenum complexes can be used in any process with process equipment that is subject to the formation and deposition of foulants (e.g., polymers) on process equipment. In some embodiments, sulfur-containing molybdenum complexes can prevent polymers from polymerizing and depositing on process equipment in primary fractionation processes, light end fractionation, non-aromatic halogenated vinyl fractionation, process gas compression, dilution steam systems, caustic towers, quenching water towers, butadiene extraction. In some embodiments, sulfur-containing molybdenum complexes can inhibit the polymerization of resins and compositions containing unsaturated substances. In some embodiments, scaling is inhibited by passivating the surface of processing equipment using sulfur-containing molybdenum complexes.

[0075] Sulfur-containing molybdenum complexes are not used in process equipment such as engines, hydraulic brakes, power steering systems, or transmissions, nor are sulfur-containing molybdenum complexes used as coolant additives in hydraulic fluids.

[0076] In some embodiments, the sulfur-containing molybdenum complex is introduced into the fluid by a method suitable for ensuring dispersion of the sulfur-containing molybdenum complex throughout the fluid source being treated. Depending on the application and requirements, the composition comprising the sulfur-containing molybdenum complex can be injected as prepared or formulated in one or more additional solvents. Those skilled in the art will appreciate that the methods disclosed herein are not limited in any way by the method, time, or location of introduction.

[0077] In some embodiments, the sulfur-containing molybdenum complex or the sulfur-containing molybdenum complex in the composition is introduced into the fluid source using various well-known methods, and they can be introduced at many different locations throughout a given system. In one embodiment, an umbilical line is used to pump the composition containing the molybdenum-containing chemical into an oil / gas pipeline. In some embodiments, a capillary column injection system can be used to deliver the composition. U.S. Patent No. 7,311,144 provides a description of apparatus and methods related to capillary injection, the disclosure of which is incorporated herein in its entirety. In other embodiments, the composition containing one or more sulfur-containing molybdenum complexes is injected using mechanical equipment such as a chemical injection pump, a pipe tee, an injection fitting, and the like.

[0078] In some embodiments, the sulfur-containing molybdenum complex is introduced into process equipment or a fluid in contact with process equipment. In some embodiments, the process equipment is used to refine, store, transport, fractionate, or otherwise process hydrocarbons, such as crude oil, natural gas, petroleum, and petroleum fractions.

[0079] The sulfur-containing molybdenum complex or the sulfur-containing molybdenum complex in the composition is introduced into the process equipment to form treated process equipment. In some embodiments, the treated process equipment is observed to experience less foulant deposition than process equipment that does not have the sulfur-containing molybdenum complex or the sulfur-containing molybdenum complex in the composition added.

[0080] The inhibition of foulant formation or foulant deposition can be assessed by any known method or test. In some embodiments, the inhibition of foulant formation and foulant deposition on process equipment can be assessed by measuring the weight gain caused by foulant deposition, as described in Examples 1 and 2.

[0081] The sulfur-containing molybdenum complex or the sulfur-containing molybdenum complex in the composition can be used on any process equipment having a metal surface. In some embodiments, the metal surface of the process equipment is a metal or metal alloy. For example, the metal surface can include steel (including carbon steel, stainless steel, galvanized steel, hot-dip galvanized steel, electrogalvanized steel, annealed hot-dip galvanized steel, or mild steel), nickel, titanium, tantalum, aluminum, copper, gold, silver, platinum, zinc, nickel-titanium alloy (nitinol), alloys of nickel, chromium, iron, iridium, tungsten, silicon, magnesium, tin, alloys of any of the foregoing metals, coatings containing any of the foregoing metals, and combinations thereof. In some embodiments, the metal surface of the process equipment is an iron alloy, carbon steel, stainless steel, nickel-chromium-iron alloy, or other alloys.

[0082] In some embodiments, foulant deposition within process equipment treated with the sulfur-containing molybdenum complex is reduced by at least 50 wt %, compared to process equipment not treated with the molybdenum-containing foulant, and in some embodiments, from about 50 wt % to 100 wt % (wherein a 100 wt % reduction in polymer formation is the elimination of deposition), or from about 50 wt % to 95 wt %, or from about 50 wt % to 90 wt %, or from about 50 wt % to 85 wt %, or from about 50 wt % to 80 wt %, or from about 50 wt % to 75 wt %, or from about 50 wt % to 70 wt %, or from about 55 wt % to 100 wt %, or from about 60 wt % to 100 wt %, or from about 65 wt % to 100 wt %, or from about 70 wt % to 100 wt %, or from about 60 wt % to 95 wt %, or from about 70 wt % to 95 wt %, or from about 60 wt % to 90 wt %, or from about 70 wt % to 90 wt %. The effectiveness of the sulfur-containing molybdenum complexes in reducing fouling can be assessed by measuring the weight gain resulting from foulant deposition, as described in the Examples.

[0083] A method for passivating the surface of process equipment using a molybdenum complex to provide treated process equipment. The treated process equipment reduces (e.g., inhibits) scaling on the metal surface. Examples of passivation are described in U.S. Patent Nos. 4,024,050, 3,522,093, 6,228,253, ASTM A-967, and ASTM A-380, which are incorporated herein by reference in their entireties. In some embodiments, passivation is performed before the process equipment is used in hydrocarbon processing (e.g., before hydrocarbon cracking) and / or after the process equipment has been decoked or cleaned, and is referred to herein as pre-passivation.

[0084] In some embodiments, the sulfur-containing molybdenum complex is introduced into the hydrocarbon feedstock prior to or during processing of the hydrocarbon feedstock and is referred to herein as passivation. In the pre-passivation or passivation process, in some embodiments, the molybdenum complex is introduced continuously or intermittently.

[0085] In some embodiments, the sulfur-containing platinum complex is introduced at an initial dosage rate for a short period of time to produce a coating on the metal surface. In some embodiments, the sulfur-containing platinum complex is introduced at a rate of about 1 ppm to about 3,000 ppm, or about 500 ppm to about 2,000 ppm, and maintained at this level for a period of time ranging from 12 hours to 48 hours, or from 12 hours to 24 hours, until the sulfur-containing platinum complex induces a protective coating (e.g., an unreactive coating) to accumulate on the metal surface. In other embodiments, the sulfur-containing platinum complex is administered at a concentration of at least twice the initial dosage rate for a period of time ranging from 1 hour to 12 hours prior to the introduction of the fluid to be processed. In some embodiments, the sulfur-containing platinum complex is introduced at a rate of about 1000 ppm to about 3,000 ppm for a period of time ranging from 6 hours to 12 hours.

[0086] In other embodiments, the sulfur-containing molybdenum complex is dosed at a concentration of at least twice the initial dosage rate for a period of 1 hour to several hours while the fluid to be processed is introduced.

[0087] Once a protective surface is established, the dosage rate required to maintain protection can be reduced from 1 ppm to 3000 ppm to at least 1 ppm to 1000 ppm. In some embodiments, the dosage for continuously applying the sulfur-containing molybdenum complex to the fluid is 1 ppm to 1500 ppm; 1 ppm to 1000 ppm; 1 to 500 ppm, 1 to 250 ppm, 100 to 200 ppm, or 500 to 1000 ppm without substantially sacrificing protection.

[0088] In some embodiments, a sulfur-containing molybdenum complex is used as disclosed in U.S. Provisional Application No. 63 / 058,010, filed on July 29, 2020.

[0089] Examples

[0090] The following examples are intended to illustrate different aspects and embodiments of the present application and should not be considered to limit the scope of the present application. It should be appreciated that various modifications and changes can be made without following the experimental embodiments described herein and without departing from the scope of the claims.

[0091] Example 1 - High Temperature Organic Scaling Inhibition

[0092] The sulfur-containing molybdenum complexes used as anti-coking inhibitors were evaluated by weight growth of SS304 mesh coupons from coke deposits.A reactor setup was used to simulate coking process conditions and temperatures.

[0093] Table 1 shows the experimental conditions used in the autoclave tests:

[0094] Table 1. Experimental parameters used in high temperature anti-fouling test

[0095]

[0096] Anti-fouling test (continuous dosing process)

[0097] The SS304 mesh (described above) was weighed on an analytical balance and inserted into the high-pressure / high-temperature autoclave vessel. 50 g of the vacuum distillation bottoms were then added to the autoclave. The vessel was then closed and sealed. The vessel was purged with N2 and pressurized. While heating the vessel to 410°C, the reactor contents were continuously mixed. Once the medium reached the target temperature of 410°C, the pyrolysis experiment time began.

[0098] At the end of the reaction time of about 40 minutes, the autoclave was cooled and the reactor pressure was released. Subsequently, the net was removed from the reactor and washed with toluene. The weight gain was measured and the weight gain was calculated.

[0099] Figure 1 The response of test complex A (molybdenum dithiocarbamate) to the tested residual deposit amount is shown in comparison with comparative complex 1 (formaldehyde resin) and comparative complex 2 (olefin copolymer). The repeatability of the pyrolysis experiments in the mentioned reactor was ±1 mg. Figure 1 It was also shown that Test Complex A was equal to or better than the Comparative Complex chemistries.Test Complex A and Comparative Complex 1 reduced surface coke deposition to a similar extent as the current residual feed samples when they were used as anti-coke chemistries.

[0100] Example 2 - High Temperature Organic Scale Inhibition (Prophetic)

[0101] Sulfur-containing molybdenum complexes used as anti-coking inhibitors were evaluated by weight growth of SS304 mesh coupons from coke deposits at pre-passivation doses. A reactor setup was used to simulate coking process conditions and temperatures.

[0102] Table 2 shows the experimental conditions that will be used in the autoclave tests:

[0103] Table 2. Experimental parameters used in high temperature anti-fouling test

[0104]

[0105]

[0106] Net pre-passivation step

[0107] 500 mL of paraffin oil solution was placed in a 1 L glass reactor and heated to 250°C.

[0108] The metal mesh will first be weighed on an analytical balance (four decimal places). Next, the mesh will then be immersed in paraffin oil that will be heated at 250°C and continuously purged with nitrogen. A 1000 ppm dose of the tested antifoulant composition will be added to the heated oil, and the resulting paraffin oil solution will be stirred at 250°C for 1 hour. This heating and introduction of the test antifoulant simulates the process of a real unit, where the passivating agent will be applied in a hydrocarbon medium at a high concentration for a short time (12 to 24 hours) during the heating of the equipment. After 1 hour of passivation, the heating will be stopped. Once the oil has cooled down (≤80°C), the mesh will be removed from the oil, washed with toluene and isopropanol, and dried using a stream of nitrogen.

[0109] The pre-passivated SS304 mesh (described above) will be weighed on an analytical balance (four decimal places) and inserted into the high-pressure / high-temperature autoclave vessel. 50 g of vacuum distillation bottoms or any other type of hydrocarbon stream will then be added to the autoclave. The vessel will then be sealed and tightened using a set of bolts / screws. The atmosphere within the vessel will first be purged with N2 using three rounds of 100 psi N2 fill / release. The vessel will then be pressurized to 100 psi with N2 and then inserted into the heating element or hood. The reactor contents will be continuously mixed while the vessel is heated to 410°C. Once the target temperature of 410°C is reached, the pyrolysis experiment time will begin.

[0110] The autoclave will then be cooled to 350°C, the pressure within the vessel will be released, and then purged with N2. Next, the heating jacket will be turned off, and the vessel temperature will be lowered below 150°C, the autoclave will be removed from the heating jacket and disassembled, and the screen will be removed and cleaned with toluene. The dried screen will be weighed using the same analytical balance that was initially used to weigh the pre-passivated SS304 screen, and the weight gain will be calculated.

[0111] The compounds tested according to the above procedure will be test complexes such as sulfur-containing molybdenum thiols; sulfur-containing molybdenum dialkyldithiocarbamates; sulfur-containing molybdenum dialkyldithiocarbonates; sulfur-containing molybdenum dialkyldithioacids and sulfur-containing molybdenum polysulfides, and will be compared to the following: comparative complexes such as mixtures of mono- and dialkyl phosphates or organic or inorganic polysulfides; or mercaptides or other benchmark anti-scorch chemicals such as magnesium-based products and test complex A, comparative complexes 1 and 2 as described in Example 1.

[0112] The present application disclosed illustratively herein can be suitably practiced in the absence of any elements specifically disclosed herein. In addition, as described herein, each embodiment of the present application is intended to be used alone or in combination with any other embodiment described herein and its modifications, equivalents and alternatives. In various embodiments, the present application suitably comprises the elements described herein and as claimed in the claims, consists essentially of the elements described herein and as claimed in the claims, or consists of the elements described herein and as claimed in the claims. It should be appreciated that various modifications and changes may be made without following the example embodiments and applications shown and described herein and without departing from the scope of the claims.

Claims

1. Use of an antifoulant composition for inhibiting the deposition of foulants in process equipment, wherein the metal surface of the process equipment is in contact with a fluid containing foulants, the use comprising: The antifoulant composition is introduced into the process equipment or fluid, wherein the antifoulant composition comprises a sulfur-containing molybdenum complex having a general formula selected from Formula I, II, III, IV, V, or VI: wherein R of Formula I represents a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and does not contain phosphorus, and n of Formula I is 4-10; wherein R and R' of Formula II each represent a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and do not contain phosphorus; and X of Formula II represents oxygen or sulfur, but at least one X is sulfur; wherein R of formula III represents an oxygen-, nitrogen-, or carbon-containing group and does not contain phosphorus, and n of formula III is 2-6; or Wherein, the arcs in Formula IV, Formula V and Formula VI represent: linear, branched and cyclic alkyl chains with or without saturation, not containing heteroatoms; linear, branched and cyclic alkyl chains with or without saturation, containing heteroatoms; thiolates, sulfides, thiocarbamates, thiocarbonates, thioacids, and aromatic rings with or without substituents.

2. Use according to claim 1, wherein the fluid comprises at least a liquid hydrocarbon material.

3. The use according to claim 1 or 2, wherein the foulant is a foulant selected from the group consisting of coke, sludge, corrosion products, polymers and catalyst fines.

4. The use according to claim 1 or 2, wherein the sulfur-containing molybdenum complex is added to the fluid in a fluid volume in the range of 1 ppm to 3000 ppm.

5. The use according to claim 1 or 2, wherein the fluid comprises one or more asphaltene inhibitors, paraffin inhibitors, scale inhibitors, emulsifiers, water clarifiers, dispersants, demulsifiers, or any combination thereof.

6. The use according to claim 1 or 2, wherein the antifoulant composition comprises a sulfur-containing molybdenum complex having formula III.

7. The use according to claim 1, wherein the antifoulant composition comprises a sulfur-containing molybdenum complex having formula IV.

8. The use according to claim 1, wherein one of the following is present: The antifoulant composition comprises a sulfur-containing molybdenum complex having the general formula I; or The antifoulant composition includes a sulfur-containing molybdenum complex having the general formula II.

9. The method according to claim 1, wherein the sulfide is selected from organic polysulfides and inorganic polysulfides.

10. A composition, wherein the composition comprises: i) a fluid containing scale, and ii) an anti-foulant comprising a sulfur-containing molybdenum complex, wherein the composition comprises 1 ppm to 3000 ppm of the sulfur-containing molybdenum complex by volume of the fluid, and the amount of the anti-foulant is effective to inhibit the deposition of scale when the fluid contacts process equipment, Wherein the sulfur-containing molybdenum complex is selected from Formula I, II, III, IV, V or VI: wherein R of Formula I represents a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and does not contain phosphorus, and n of Formula I is 4-10; wherein R and R' of Formula II each represent a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and do not contain phosphorus; and X of Formula II represents oxygen or sulfur, but at least one X is sulfur; wherein R of formula III represents an oxygen-, nitrogen-, or carbon-containing group and does not contain phosphorus, and n of formula III is 2-6; or Wherein, the arcs in Formula IV, Formula V and Formula VI represent: straight-chain, branched and cyclic alkyl chains with or without saturation, not containing heteroatoms; straight-chain, branched and cyclic alkyl chains with or without saturation, containing heteroatoms; thiolates, sulfides, thiocarbamates, thiocarbonates, thioacids, and aromatic rings with or without substituents.

11. The composition of claim 10, wherein the composition further comprises one or more asphaltene inhibitors, paraffin inhibitors, scale inhibitors, emulsifiers, water clarifiers, dispersants, demulsifiers, or any combination thereof.

12. The composition according to claim 10 or 11, wherein the antifouling agent comprises a sulfur-containing molybdenum complex having formula III.

13. The composition according to claim 10, wherein the antifoulant comprises a sulfur-containing molybdenum complex having Formula IV.

14. The composition according to claim 10, wherein the composition comprises one of the following: The antifoulant composition comprises a sulfur-containing molybdenum complex having formula I; or The antifoulant composition includes a sulfur-containing molybdenum complex having the general formula II.

15. A method for pre-passivating a metal surface of a process equipment, comprising the following steps: An antifoulant composition is contacted with the metal surface of the process equipment, wherein the antifoulant composition comprises a sulfur-containing molybdenum complex having a general formula selected from Formula I, II, III, IV, V, or VI: wherein R of Formula I represents a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and does not contain phosphorus, and n of Formula I is 4-10; wherein R and R' of Formula II each represent a group selected from the group consisting of an alcohol group, an alkyl group, an alkenyl group, and an aryl group and do not contain phosphorus; and X of Formula II represents oxygen or sulfur, but at least one X is sulfur; wherein R of formula III represents an oxygen-, nitrogen-, or carbon-containing group and does not contain phosphorus, and n of formula III is 2-6; or The arcs in Formula IV, Formula V, and Formula VI represent groups selected from: groups consisting of linear, branched, and cyclic alkyl chains that do not contain heteroatoms and may or may not be saturated; linear, branched, and cyclic alkyl chains that contain heteroatoms and may or may not be saturated; thiolates, sulfides, thiocarbamates, thiocarbonates, thioacids, and aromatic rings that may or may not have substituents.

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