Reduction of heat exchanger fouling

Abstract

A method of reducing or inhibiting fouling deposit formation from liquid hydrocarbons within an anaerobic environment. The method includes a liquid hydrocarbon and an antifouling composition combined to reduce or inhibit deposits when the liquid hydrocarbon is heated to temperatures of about 100°C or greater in an anaerobic environment. The antifouling composition includes one or more linear or branched alkali or alkaline earth metal salts and / or one or more nitrogen-containing alkenyl succinimides.

Description

REDUCTION OF HEAT EXCHANGER FOULINGCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 U.S.C. § 120 to US Non-Provisional Application No. 19 / 402,117 filed on November 26, 2025, which claims the benefit of U.S. Provisional Application No. 63 / 730,868, filed on December 11, 2024, which are both hereby incorporated herein by reference in their entirety.TECHNICAL FIELD

[0002] The present disclosure relates to methods for providing antifouling for liquid hydrocarbons, such as petroleum hydrocarbons, petrochemical fluids, and / or heating oils, during processing at elevated temperatures.BACKGROUND

[0003] In processing of liquid hydrocarbons, such as petroleum hydrocarbons, liquid petrochemicals, and / or olefin industrial fluids to suggest but a few examples, the hydrocarbons are commonly heated to elevated temperatures of about 100°C or higher, about 300°C or higher, and often up to about 600°C or higher. Similarly, liquid hydrocarbon fluids are often used as heating oils on the hot side of a heat exchange system. In both instances, the liquid hydrocarbons are subjected to the elevated temperatures that tends, in some instances, to result in degradation and / or fouling deposits, which typically build up at the hot surfaces of the heat exchanger or other processing equipment hot surfaces. These deposits are often deleterious to operations due to reduced heat transfer from the buildup. In some instances, excessive buildup of deposits may also have a negative cascade impact to performance because the subsequent lower heat transfer requires even more heat on the supply side to yield the same effective heating rate, which then causes even further degradation to occur. In addition to the thermodynamic problems of the fouling, such deposits and degradation can also cause other problems beyond heat exchanger surfaces because the deposits can also cause blockages in process passages, reduce flow rates, clog filters, and / or block valves.

[0004] Unfortunately, the exact nature of the formed deposits is difficult to fully characterize. However, due to the process conditions generally being conducted in largely anaerobic conditions, it is believed that the deposits have a general composition similar to coke, varnish,163005438.1and / or sludge. These materials result from the thermal cracking and / or rearrangement of the oil molecules forming high molecular weight compounds and more thermodynamically stable compounds such as aromatics. The nature of the deposits produced, therefore, makes removing them after formation challenging. The need to remove deposits manually can lead to significant cost to process operations as units need to be removed from service for cleaning and restoration.SUMMARY

[0005] In one approach or embodiment, a method of reducing, inhibiting, or cleaning-up fouling deposit formation from liquid hydrocarbons within an anaerobic environment is described herein. In aspects of this approach, the method includes combining a liquid hydrocarbon and an antifouling composition to reduce, inhibit, or clean-up deposits when the liquid hydrocarbon is heated to temperatures of about 100°C or greater in an anaerobic environment. In other aspects, the antifouling composition includes (a) one or more linear or branched alkali or alkaline earth metal salts, (b) one or more nitrogen-containing alkenyl succinimides, and / or combinations of (a) and (b).

[0006] In yet other approaches or embodiments, the methods of the previous paragraph may include other features, steps, or embodiments in any combination. These other features, steps, or embodiments include one or more of the following: wherein the antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts, and preferably wherein the one or more linear or branched alkali or alkaline earth metal salts is one or more linear or branched alkyl benzene or toluene sulfonates; and / or wherein the linear or branched alkyl benzene or toluene sulfonate has a total base number (TBN) as measured per ASTM D2896 of less than 250 mg KOH / g; and / or wherein the linear or branched alkyl benzene or toluene sulfonate has a TBN as measured per ASTM D2896 of about 100 mg KOH / g or less, or more preferably a TBN of about 50 mg KOH / g or less; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts provide up to about 500 ppm of metal (e.g., calcium) to the liquid hydrocarbon (or about 25 to about 400 ppm calcium, about 30 to about 300 ppm calcium); and / or wherein the antifouling composition includes the (b) one or more nitrogencontaining alkenyl succinimides, and preferably wherein the one or more nitrogen-containing alkenyl succinimides is a polyisobutylene succinimide and wherein the polyisobutylene substituent thereof has a number average molecular of about 500 to about 5,000 g / mol (or about263005438.1500 to about 3,000 g / mol, or about 700 to about 2,500 g / mol, or about 800 to about 2,000 g / mol, or about 900 to about 1,500 g / mol); and / or wherein the nitrogen-containing alkenyl succinimide is derived by reacting polyisobutylene with an acylating agent to form an acylated polyisobutylene and reacting the acylated polyisobutylene with a nitrogen source; and / or wherein the acylating agent is fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid, dimethyl maleic acid, hexylmaleic acid, anhydrides thereof, or combinations thereof; and / or wherein the nitrogen source is ammonia, a polyalkylene polyamine, polyethylene polyamines having 5 or an average of 5 nitrogen atoms, diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylamine hexamine (PEHA), or combinations thereof; and / or wherein the nitrogen-containing alkenyl succinimide is post-treated with boron, boron compounds, urea, thiourea, dimercapto thiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compound or combinations thereof; and / or wherein the polyisobutylene (PIB) has greater than about 50 mol percent of terminal double bonds (or greater than 60 mol percent, greater than 70 more percent, greater than 80 mol percent, or greater than 90 mol percent of terminal double bonds); and / or wherein antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts and the (b) one or more nitrogen-substituted alkenyl succinimides; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts has a TBN as measured per ASTM D2896 of less than 250 mg KOH / g and the one or more nitrogen- containing alkenyl succinimides has an alkenyl substituent thereof having a number average molecular weight of about 1600 g / mol or less; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts has a total base number (TBN) as measured per ASTM D2896 of 250 mg KOH / g or more and the one or more nitrogencontaining alkenyl succinimides has an alkenyl substituent thereof having a weight average molecular weight greater than 1600 g / mol; and / or wherein the antifouling composition further includes a phosphorus containing compound selected from thiophosphates, dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus- containing carboxylic esters, ethers, or amine salts thereof, or mixtures thereof; and / or wherein the phosphorus-containing compound is a phosphorodithioic acid, ester, and / or salt thereof;363005438.1and / or wherein the phosphorus-containing compound is a phosphorodithioc acid, ester, or salt thereof derived from one of ethylhexanol, iso-propanol, iso-butanol, or combinations thereof (preferably, from ethylhexanol and isobutanol); and / or wherein the phosphorodithioic acid, ester, or salt thereof includes one or more of a phosphorodithioic acid including O,O-bis(2-ethylhexyl and iso-butyl) esters with triethylamine.

[0007] In yet other approaches, the present disclosure provides an antifouling composition suitable for use with liquid hydrocarbons and preferably suitable for use with liquid hydrocarbons at elevated temperatures (e.g., about 100°C or greater as defined above) and within an anaerobic environment. The antifouling composition may be used in any embodiment of the methods as described in the present Summary. In aspects, the antifouling composition includes (a) one or more linear or branched alkali or alkaline earth metal salts and / or (b) one or more nitrogen-containing alkenyl succinimides and (c) optionally one or more phosphorus containing compounds.

[0008] In yet other approaches or embodiments, the antifouling composition of the previous paragraph may include other features or embodiments in any combination. These other features or embodiments include one or more of the following: wherein the antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts, and preferably wherein the one or more linear or branched alkali or alkaline earth metal salts is one or more linear or branched alkyl benzene or toluene sulfonates; and / or wherein the linear or branched alkyl benzene or toluene sulfonate has a total base number (TBN) as measured per ASTM D2896 of less than 250 mg KOH / g; and / or wherein the linear or branched alkyl benzene or toluene sulfonate has a TBN as measured per ASTM D2896 of about 100 mg KOH / g or less, or a TBN of about 50 mg KOH / g or less; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts provide up to about 500 ppm of metal (e g., calcium) to the liquid hydrocarbon (or about 25 to about 400 ppm calcium, about 30 to about 300 ppm calcium); and / or wherein the antifouling composition includes the (b) one or more nitrogen-containing alkenyl succinimides, and preferably wherein the one or more nitrogen-containing alkenyl succinimides is a polyisobutylene succinimide and wherein the polyisobutylene substituent thereof has a number average molecular of about 500 to about 5,000 g / mol (or about 500 to about 3000 g / mol, or about 700 to about 2500 g / mol, or about 800 to about 2000 g / mol, or about 900 to about 1500 g / mol); and / or wherein the nitrogen-containing alkenyl succinimide is derived by reacting463005438.1polyisobutylene with an acylating agent to form an acylated polyisobutylene and reacting the acylated polyisobutylene with a nitrogen source; and / or wherein the acylating agent is fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid, dimethyl maleic acid, hexylmaleic acid, anhydrides thereof, or combinations thereof; and / or wherein the nitrogen source is ammonia, a polyalkylene polyamine, polyethylene polyamines having 5 or an average of 5 nitrogen atoms, di ethylene triamine (DETA), tri ethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylamine hexamine (PEHA), or combinations thereof; and / or wherein the nitrogen-containing alkenyl succinimide is post-treated with boron, boron compounds, urea, thiourea, dimercapto thiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compound or combinations thereof; and / or wherein the polyisobutylene (PIB) has greater than about 50 mol percent of terminal double bonds (or greater than 60 mol percent, greater than 70 more percent, greater than 80 mol percent, or greater than 90 mol percent of terminal double bonds); and / or wherein antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts and the (b) one or more nitrogen-containing alkenyl succinimides; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts has a TBN as measured per ASTM D2896 of less than 250 mg KOH / g and the one or more nitrogencontaining alkenyl succinimides has an alkenyl substituent thereof having a number average molecular weight of about 1600 g / mol or less; and / or wherein the one or more linear or branched alkali or alkaline earth metal salts has a total base number (TBN) as measured per ASTM D2896 of 250 mg KOEI / g or more and the one or more nitrogen-containing alkenyl succinimides has an alkenyl substituent thereof having a weight average molecular weight greater than 1600 g / mol; and / or wherein the antifouling composition further includes a phosphorus containing compound selected from thiophosphates, dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic esters, ethers, or amine salts thereof, or mixtures thereof; and / or wherein the phosphorus-containing compound is a phosphorodithioic acid, ester, and / or salt thereof; and / or wherein the phosphorus-containing compound is a phosphorodithioc acid, ester, or salt thereof derived from one of ethylhexanol, iso-propanol, iso-butanol, or combinations thereof (preferably, from ethylhexanol and563005438.1isobutanol); and / or wherein the phosphorodithioic acid, ester, or salt thereof includes one or more of a phosphorodithioic acid including O,O-bis(2-ethylhexyl and iso-butyl) esters with triethylamine.

[0009] In yet other approaches, the present disclosure provides for the use an antifouling composition with liquid hydrocarbons, and preferably at elevated temperatures (e.g., about 100°C or greater as defined above) and within an anaerobic environment, to achieve an average change in delta temperature (e.g., a Temperature Difference Deviation (TDD) as defined hereinbelow) across a 316 stainless steel tube (with the tube at 450°C and liquid hydrocarbons at 200 psi) as measured and described hereinbelow using a Falex FT2 thermal fouling apparatus (Falex Corporation, Illinois, USA) of about 0°C or more (preferably about 0cC to about 0.5°C average change in delta temperature or TDD). In aspects, the antifouling composition includes any embodiment of the methods or compositions as described in this Summary and at least (a) one or more linear or branched alkali or alkaline earth metal salts; and / or (b) one or more nitrogen-containing alkenyl succinimides; and (c) optionally one or more phosphorus containing compounds.DRAWING FIGURE

[0010] FIG. 1 illustrated an exemplary temperature profile from a Falex Thermal FoulingTester (FT2) suitable for determination of a Temperature Difference Deviation (TDD) as described herein.DETAILED DESCRIPTION

[0011] The present disclosure relates to methods of reducing, inhibiting, and / or cleaning-up fouling deposit formation in liquid hydrocarbons during heating at elevated temperatures, such as temperatures of at least about 100°C or greater, at least about 300°C or greater, at least about 400°C or greater, at least about 500°C or greater, or at least about 600°C or greater. In one embodiment, the method includes adding to or combining with the liquid hydrocarbon an antifouling composition including, in one aspect, (a) one or more linear or branched alkali or alkaline earth metal salts, (b) one or more nitrogen-containing alkenyl succinimides, or combinations of the one or more linear or branched alkali or alkaline earth metal salts and the one or more nitrogen-containing alkenyl succinimides. In another aspect of this embodiment, the methods herein include adding to the liquid hydrocarbon an antifouling composition including663005438.1(a) one or more linear or branched alkali or alkaline earth metal salts; and / or (b) one or more nitrogen-containing alkenyl succinimides; and optionally (c) one or more phosphorus-containing compounds. The present disclosure also relates to such antifouling compositions. As discussed more herein, the discovered antifouling compositions and methods surprisingly provide a synergistic improvement in reducing, inhibiting, and / or cleaning-up fouling deposits of the liquid hydrocarbon at the elevated temperatures and under anaerobic conditions as determined, for instance, by a consistent amount of heat transfer (as defined below as a Temperature Difference Deviation or TDD) over time. As discussed below, heat transfer can be determined using a Falex Thermal Fouling tester (FT2) (Falex Corporation, Illinois, USA)

[0012] Alkali or Alkaline Earth Metal Salts

[0013] In one approach or embodiment, the antifouling composition may include one or more linear or branched alkali or alkaline earth metal salts, which in some embodiments may be linear or branched alkali or alkaline earth metal salts (such as calcium, sodium, and / or magnesium) of petroleum sulfonic acids and / or long chain mono- or di-alkylaryl sulfonic acids with the aryl group being benzyl, tolyl, and xylyl and / or, in other approaches, various phenates or derivatives of phenates. Preferably, the one or more linear or branched alkali or alkaline earth metal salts include one or more linear or branched alkyl benzene or toluene sulfonates.

[0014] Examples of suitable alkali or alkaline earth metal salts include: calcium phenates, calcium sulfur containing phenates, calcium sulfonates, calcium calixarates, calcium salixarates, calcium salicylates, calcium carboxylic acids, calcium phosphorus acids, calcium mono- and / or di-thiophosphoric acids, calcium alkyl phenols, calcium sulfur coupled alkyl phenol compounds, calcium methylene bridged phenols, magnesium phenates, magnesium sulfur containing phenates, magnesium sulfonates, magnesium calixarates, magnesium salixarates, magnesium salicylates, magnesium carboxylic acids, magnesium phosphorus acids, magnesium mono- and / or di-thiophosphoric acids, magnesium alkyl phenols, magnesium sulfur coupled alkyl phenol compounds, magnesium methylene bridged phenols, sodium phenates, sodium sulfur containing phenates, sodium sulfonates, sodium calixarates, sodium salixarates, sodium salicylates, sodium carboxylic acids, sodium phosphorus acids, sodium mono- and / or di- thiophosphoric acids, sodium alkyl phenols, sodium sulfur coupled alkyl phenol compounds, or sodium methylene bridged phenols.763005438.1

[0015] Suitable alkali or alkaline earth metal salts and their methods of preparation are described in greater detail in numerous patent publications, including US 7,732,390; US 4,165,291; and / or US 4,206,062 (and references cited therein), which are incorporated herein by reference. In one approach, the alkali or alkaline earth metal salts suitable for the antifouling composition of the present disclosure is one or more of calcium, sodium, or magnesium sulfonate (e.g., linear or branched alkylbenzene sulfonates having a hydrophilic sulfonate group and a hydrophobic alkylbenzene group). As appreciated, such sulfonate compounds can be neutral to overbased as measured by Total Base Number (TBN) in mg KOH / g as by the methods of ASTM D2896. For example, a low-base or neutral alkali or alkaline earth metal salt herein may have a total base number (TBN) of up to 250 mg KOH / gram (e.g., 0 to 250, 0 to about 100, or 0 to about 50, or 0 to about 25 mg KOH / g). Overbased alkali or alkaline earth metal salts may have a total base number (TBN) of 250 mg KOH / gram or greater, about 300 mg KOH / gram or greater, about 350 mg KOH / gram or greater, about 375 mg KOH / gram or greater, or about 400 mg KOH / gram or greater (e.g., 250 to about 500, about 300 to about 450, about 350 to about 450, or about 350 to about 400 mg KOH / g). The overbased alkali or alkaline earth metal salts may also have a metal to substrate ratio of from 1.1 :1 or less, or from 2: 1 or less, or from 4: 1 or less, or from 5: 1 or less, or from 7: 1 or less, or from 10: 1 or less, or from 12: 1 or less, or from 15: 1 or less, or from 20: 1 or less. In one embodiment, suitable alkali or alkaline earth metal salts for the antifouling composition are neutral to low-based calcium sodium, and / or magnesium sulfonates (e.g., linear or branched alkylbenzene sulfonates having a hydrophilic sulfonate group and a hydrophobic alkylbenzene group) with a TBN of 0 to 250, 0 to about 100, or 0 to about 50, and in other embodiment, the alkali or alkaline earth metal salts are overbased calcium, sodium, and / or magnesium sulfonates having a TBN of 250 or higher.

[0016] In one embodiment, the antifouling composition may provide about 0.05 to about 2 weight percent of the alkali or alkaline earth metal salts (e.g., calcium sulfonate) to the liquid hydrocarbon medium and, in other embodiments, about 0.08 to about 1 weight percent, about 0.1 to about 0.5 weight percent, or about 0.1 to about 0.2 weight percent of the alkali or alkaline earth metal salt (such as an linear or branched alkyl benzene sulfonate). In other approaches, the antifouling compositions include amounts of the alkali or alkaline earth metal salts to provide about 10 to about 1000 ppm metal (e.g., calcium) to the liquid hydrocarbon medium, or in other embodiments, about 20 to about 500 ppm metal, or about 30 to about 200 ppm metal (e.g.,863005438.1calcium), or about 30 to about 160 ppm metal (e.g., calcium) to the liquid hydrocarbon medium (and in other embodiments, about 20 to about 50 ppm metal (e.g., calcium) or in further embodiments, about 100 to about 200 ppm metal (e.g., calcium)).

[0017] The alkali or alkaline earth metal salts herein also provide a soap content to the liquid hydrocarbon. As understood, soap content generally refers to the amount of neutral organic acid salt and otherwise reflects the cleansing ability, detergency, and / or dirt suspending ability of the alkali or alkaline earth metal salt. As used herein, the soap content of a liquid hydrocarbon can be determined by ASTM D3712. Further discussion on determining soap content can be found in FUELS AND LUBRICANTS HANDBOOK, TECHNOLOGY, PROPERTIES, PERFORMANCE, AND TESTING, George Totten, editor, ASTM International, 2003, relevant portions thereof incorporated herein by reference. In embodiments, the alkali or alkaline earth metal salts of the antifouling composition may contribute about 0.2 mmol to about 8 mmol of soap to the liquid hydrocarbon, and in other embodiments, about 0.5 mmol to about 4 mmol, about 0.5 to about 2 mmol, or about 0.5 to about 1 mmol of soap to the liquid hydrocarbon.

[0018] Nitrogen-containing alkenyl succinimide

[0019] In another approach or embodiment, the antifouling composition may also include (either individually or combined with the metal salts discussed above) one or more nitrogencontaining alkenyl succinimide compounds, such as a polyisobutylene succinimide with a number average molecular weight of the polyisobutylene substituent of about 350 to about 50,000 g / mol; about 350 to about 10,000; or about 350 to about 5,000; or about 500 to about 3,000; or about 800 to about 2000, or about 900 to about 1500 as measured by GPC.

[0020] Polyisobutylene succinimide compounds and their preparation are disclosed, for instance in U.S. Pat. No. 7,897,696 or U.S. Pat. No. 4,234,435, which are incorporated herein by reference. In one approach, the alkenyl substituent of the succinimide compound may be prepared from polymerizable monomers containing about 2 to about 16, or about 2 to about 8, or about 2 to about 6 carbon atoms. Succinimide moieties are typically the imide formed from a polyamine, typically a poly(ethyleneamine). In embodiments, the nitrogen-substituted succinimide may provide about 600 to about 1000 ppm of nitrogen.

[0021] Preferred amines suitable for forming the nitrogen-containing alkenyl succinimide compounds may be selected from polyamines and hydroxylamines. Examples of polyamines that963005438.1may be used include, but are not limited to, diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), and higher homologues such as pentaethylamine hexamine (PEHA), heavy polyamines, and the like. A suitable heavy polyamine is a mixture of polyalkylene-polyamines comprising small amounts of lower polyamine oligomers such as TEPA and PEHA (pentaethylene hexamine) but primarily oligomers with 6 or more nitrogen atoms, 2 or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures. A heavy polyamine preferably includes polyamine oligomers containing 7 or more nitrogen atoms per molecule and with 2 or more primary amines per molecule. The heavy polyamine comprises more than about 28 weight percent (e.g. greater than about 32 weight percent) total nitrogen and an equivalent weight of primary amine groups of 120 to 160 grams per equivalent.

[0022] In some approaches, suitable polyamines are commonly known as PAM and contain a mixture of ethylene amines where TEPA and pentaethylene hexamine (PEHA) are the major part of the polyamine, usually less than about 80%. Typically, PAM has 8.7 to 8.9 milliequivalents of primary amine per gram (an equivalent weight of 115 to 112 grams per equivalent of primary amine) and a total nitrogen content of about 33 to 34 weight percent Heavier cuts of PAM oligomers with practically no TEPA and only very small amounts of PEHA but containing primarily oligomers with more than 6 nitrogen atoms and more extensive branching, may produce compounds with improved dispersancy.

[0023] In an embodiment, the present disclosure further comprises at least one polyisobutylene succinimide derived from polyisobutylene with a number average molecular weight in the range about 350 to about 50,000; about 350 to about 5000; about 350 to about 3000; or about 800 to about 2000; or about 800 to about 1500 as determined by GPC. In some embodiments, the polyisobutylene (PIB), may have greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol% content of terminal double bonds. Such PIB is also referred to as highly reactive PIB (“HR-PIB”). HR-PIB having a number average molecular weight ranging from about 800 to about 5000, as determined by GPC, is suitable for use in embodiments of the present disclosure. Conventional PIB, which may also be used, typically has less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol% content of terminal double bonds.1063005438.1

[0024] An HR-PIB having a number average molecular weight ranging from about 900 to about 3000 may be suitable, as determined by GPC. Such HR-PIB is commercially available, or can be synthesized by the polymerization of isobutene in the presence of a non-chlorinated catalyst such as boron trifluoride, as described in US Patent No. 4,152,499 to Boerzel, et al. and U.S. Patent No. 5,739,355 to Gateau, et al. When used in the aforementioned thermal ene reaction, HR-PIB may lead to higher conversion rates in the reaction, as well as lower amounts of sediment formation, due to increased reactivity. A suitable method is described in U.S. Patent No. 7,897,696.

[0025] In one embodiment, the present disclosure further comprises at least one compound derived from polyisobutylene succinic anhydride (“PIBSA”). The PIBSA may have an average of between about 1.0 and about 2.0 succinic acid moieties per polymer. The percent actives of the alkenyl or alkyl succinic anhydride can be determined using a chromato-graphic technique. This method is described in column 5 and 6 in U.S. Pat. No. 5,334,321. The percent conversion of the polyolefin is calculated from the % actives using the equation in column 5 and 6 in U.S. Pat. No. 5,334,321.

[0026] In another embodiment, the nitrogen-containing alkenyl succinimide compounds herein may be derived from a polyalphaolefin (PAO) succinic anhydride. In one embodiment, the compound may be derived from olefin maleic anhydride copolymer. As an example, the compound may be described as a poly-PIBSA. In an embodiment, the compound may be derived from an anhydride which is grafted to an ethylene-propylene copolymer. A suitable class of nitrogen-containing compounds may be derived from olefin copolymers (OCP), more specifically, ethylene-propylene dispersants which may be grafted with maleic anhydride. A more complete list of nitrogen-containing compounds that can be reacted with the functionalized OCP are described in U.S. Patent Nos. 7,485,603; 7,786,057; 7,253,231; 6,107,257; and 5,075,383; and / or are commercially available.

[0027] A suitable nitrogen-containing alkenyl succinimide compound may also optionally be post-treated by conventional methods by a reaction with any of a variety of agents. Among these post treat reactants are boron, boron compounds, urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and1163005438.1phosphorus compounds. US 7,645,726; US 7,214,649; and US 8,048,831 are incorporated herein by reference in their entireties.

[0028] In addition to the carbonate and boric acids post-treatments, the compounds may be post-treated, or further post-treatment, with a variety of post-treatments designed to improve or impart different properties. Such post-treatments include those summarized in columns 27 to 29 of US 5,241,003, hereby incorporated by reference. Such treatments include, treatment with: Inorganic phosphorous acids or anhydrates (e.g., U.S. Pat. Nos. 3,403,102 and 4,648,980); Organic phosphorous compounds (e.g., U.S. Pat. No. 3,502,677); Phosphorous pentasulfides; Boron compounds as already noted above (e.g., U.S. Pat. Nos. 3,178,663 and 4,652,387); Carboxylic acid, polycarboxylic acids, anhydrides and / or acid halides (e.g., U.S. Pat. Nos. 3,708,522 and 4,948,386); Epoxides polyepoxiates or thioexpoxides (e.g., U.S. Pat. Nos. 3,859,318 and 5,026,495); Aldehyde or ketone (e.g., U.S. Pat. No. 3,458,530); Carbon disulfide (e.g., U.S. Pat. No. 3,256,185); Glycidol (e.g., U.S. Pat. No. 4,617,137); Urea, thiourea or guanidine (e.g., U.S. Pat. Nos. 3,312,619; 3,865,813; and British Patent GB 1,065,595); Organic sulfonic acid (e.g., U.S. Pat. No. 3,189,544 and British Patent GB 2,140,811); Alkenyl cyanide (e.g., U.S. Pat. Nos. 3,278,550 and 3,366,569); Diketene (e.g., U.S. Pat. No. 3,546,243); A diisocyanate (e.g., U.S. Pat. No. 3,573,205); Alkane sultone (e.g., U.S. Pat. No. 3,749,695); 1,3- Dicarbonyl Compound (e.g., U.S. Pat. No. 4,579,675); Sulfate of alkoxylated alcohol or phenol (e.g., U.S. Pat. No. 3,954,639); Cyclic lactone (e.g., U.S. Pat. Nos. 4,617,138; 4,645,515;4,668,246; 4,963,275; and 4,971,711); Cyclic carbonate or thiocarbonate linear monocarbonate or polycarbonate, or chloroformate (e.g., U.S. Pat. Nos. 4,612,132; 4,647,390; 4,648,886;4,670, 170); Nitrogen-containing carboxylic acid (e.g., U.S. Pat. 4,971,598 and British Patent GB 2,140,811); Hydroxy-protected chlorodicarbonyloxy compound (e.g., U.S. Pat. No. 4,614,522); Lactam, thiolactam, thiolactone or dithiolactone (e.g., U.S. Pat. Nos. 4,614,603 and 4,666,460); Cyclic carbonate or thiocarbonate, linear monocarbonate or polycarbonate, or chloroformate (e.g., U.S. Pat. Nos. 4,612,132; 4,647,390; 4,646,860; and 4,670,170); Nitrogen-containing carboxylic acid (e.g., U.S. Pat. No. 4,971,598 and British Patent GB 2,440,811); Hydroxyprotected chlorodicarbonyloxy compound (e.g., U.S. Pat. No. 4,614,522); Lactam, thiolactam, thiolactone or dithiolactone (e.g., U.S. Pat. Nos. 4,614,603, and 4,666,460); Cyclic carbamate, cyclic thiocarbamate or cyclic dithiocarbamate (e.g., U.S. Pat. Nos. 4,663,062 and 4,666,459); Hydroxy aliphatic carboxylic acid (e.g., U.S. Pat. Nos. 4,482,464; 4,521,318; 4,713,189);1263005438.1Oxidizing agent (e.g., U.S. Pat. No. 4,379,064); Combination of phosphorus pentasulfide and a polyalkylene polyamine (e.g., U.S. Pat. No. 3,185,647); Combination of carboxylic acid or an aldehyde or ketone and sulfur or sulfur chloride (e.g., U.S. Pat. Nos. 3,390,086; 3,470,098); Combination of a hydrazine and carbon disulfide (e.g. U.S. Pat. No. 3,519,564); Combination of an aldehyde and a phenol (e.g., U.S. Pat. Nos. 3,649,229; 5,030,249; 5,039,307); Combination of an aldehyde and an O-diester of dithiophosphoric acid (e.g., U.S. Pat. No. 3,865,740); Combination of a hydroxyaliphatic carboxylic acid and a boric acid (e.g., U.S. Pat. No. 4,554,086); Combination of a hydroxyaliphatic carboxylic acid, then formaldehyde and a phenol (e.g., U.S. Pat. No. 4,636,322); Combination of a hydroxyaliphatic carboxylic acid and then an aliphatic dicarboxylic acid (e.g., U.S. Pat. No. 4,663,064); Combination of formaldehyde and a phenol and then glycolic acid (e.g., U.S. Pat. No. 4,699,724); Combination of a hydroxyaliphatic carboxylic acid or oxalic acid and then a diisocyanate (e.g. U.S. Pat. No.4, 713, 191); Combination of inorganic acid or anhydride of phosphorus or a partial or total sulfur analog thereof and a boron compound (e.g., U.S. Pat. No. 4,857,214); Combination of an organic diacid then an unsaturated fatty acid and then a nitrosoaromatic amine optionally followed by a boron compound and then a glycolating agent (e.g., U.S. Pat. No. 4,973,412); Combination of an aldehyde and a triazole (e.g., U.S. Pat. No. 4,963,278); Combination of an aldehyde and a triazole then a boron compound (e.g., U.S. Pat. No. 4,981,492); Combination of cyclic lactone and a boron compound (e.g., U.S. Pat. No. 4,963,275 and 4,971,711). The above-mentioned patents are herein incorporated in their entireties.

[0029] The TBN of suitable nitrogen-containing alkenyl succinimide compounds for the antifouling compositions herein may be from about 10 to about 65 mg KOH / g, on an oil-free basis, which is comparable to about 5 to about 30 TBN if measured on a sample containing about 50% diluent oil. TBN is measured by the method of ASTM D2896.

[0030] In yet other embodiments, the nitrogen-containing alkenyl succinimide compounds may be a hydrocarbyl substituted succinamide or succinimide. In approaches, the hydrocarbyl substituted succinamide or succinimide may be derived from a hydrocarbyl substituted acylating agent reacted with a polyalkylene polyamine and wherein the hydrocarbyl substituent of the succinamide or the succinimide is a linear or branched hydrocarbyl group (e.g., polyisobutylene) having a number average molecular weight of about 350 to about 5,000; about 350 to about 2000, about 800 to about 2000, or about 800 to about 1500 as measured by GPC using1363005438.1polystyrene as a calibration reference. In some approaches, the acylating agent may, for instance, fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid, dimethylmaleic acid, hexylmaleic acid, anhydrides thereof, or combinations thereof. In other approaches, the nitrogen source is ammonia, a polyalkylene polyamine, polyethylene polyamines having 5 or an average of 5 nitrogen atoms, diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylamine hexamine (PEHA), or combinations thereof. In further approaches, the nitrogen-substituted alkenyl succinimide is post-treated with boron, boron compounds, urea, thiourea, dimercapto thiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compound or combinations thereof.

[0031] In some approaches, the polyalkylene polyamine used to form the nitrogen-containing alkenyl succinimide compounds may have the Formulawherein each R and R’, independently, is a divalent Cl to C6 alkylene linker, each Ri and R2, independently, is hydrogen, a Cl to C6 alkyl group, or together with the nitrogen atom to which they are attached form a 5- or 6-membered ring optionally fused with one or more aromatic or non-aromatic rings, and n is an integer from 0 to 8. In other approaches, the polyalkylene polyamine is selected from the group consisting of a mixture of polyethylene polyamines having an average of 5 to 7 nitrogen atoms, triethylenetetramine, tetraethylenepentamine, and combinations thereof.

[0032] In embodiments herein, the antifouling composition may include amounts of the nitrogen-containing alkenyl succinimide compounds in an amount sufficient to provide up to about 1 weight percent, based upon the weight of the liquid hydrocarbon. In other embodiments, amounts of the nitrogen-containing alkenyl succinimide compounds that can be used may be about 0.01 weight percent to about 1 weight percent, or about 0.02 weight percent to about 0.5 weight percent, about 0.03 to 0.1 weight percent, or about 0.05 weight percent to about 0.08 weight percent based upon the weight of the liquid hydro carbon.1463005438.1

[0033] Phosphorus-Containing Compound

[0034] In one approach or embodiment, the antifouling composition may also include optional amounts of one or more phosphorus-containing compounds. Examples of suitable phosphorus-containing compounds include, but are not limited to, thiophosphates, dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic esters, ethers, or amine salts thereof, and mixtures thereof.

[0035] In one embodiment or approach, the antifouling composition may include a phosphate, thiophosphate, or thiophosphoric acid or ester compound or salt thereof having the structure of Formula I below:(Formula I) wherein Ri of Formula I is sulfur or oxygen; R2 and R3 are, independently, one of -OR5 or - OH, and each R5 if included is, independently, a C3 to C20 linear or branched alkyl group, a C5 to C6 cycloalkyl group, a phenyl group, or a C6 to Cl 8 alkylphenol group. R4 of Formula 1 is -SH, -OH, or if a salt, then one of -S’, or -O’. In other approaches, Ri is preferably sulfur, R2 and R3 are, independently, the -ORs group with each Rs being the same or different and a C3 to CIO linear or branched alkyl group. In yet other approaches, each Rs is preferably an isopropyl group, an isobutyl group, or an ethylhexyl group (such as a 2-ethylhexyl group).Examples of suitable phosphorus compounds are further described in US 11,958,785, which is incorporated herein by reference.

[0036] In other approaches or embodiments, the phosphorus-containing compound of the antifouling composition includes one or more phosphorodithioic acids, esters, and / or salts thereof, such as one or more of O,O-bis(alkyl) phosphorodithioic acid, ester, or amine salts thereof. In some approaches, the phosphorodithioic acids, esters, and / or salts may include one or more monoalkyl phosphorodithioic acid esters, dialkyl phosphorodithioic acid ester, and / or mixtures thereof wherein the alkyl groups thereof may be linear, branched, or cyclic. The monoalkyl or the dialkyl phosphorodithioic acid esters may also be amine salts. In approaches or1563005438.1embodiments, exemplary phosphorodithioic acids, esters, and / or amine salts thereof may be represented by Formula II(Formula II) wherein Re and R7 of Formula II above may be independently hydrogen or a linear, branched, or cyclic hydrocarbyl group; Rs, R$>, Rio and R11 of Formula II may be independently hydrogen or a hydrocarbyl group (e.g., a Cl to CIO hydrocarbyl group) and at least one of Rs to R11 of Formula II is a hydrocarbyl group. Examples of a suitable alkyl or hydrocarbyl groups for Re and / or R7 of Formula II include straight-chain or branched alkyl groups such as, but not limited to, propyl, butyl, pentyl, hexyl, ethylhexyl, heptyl, octyl, nonyl, and / or decyl groups (and iso-variants thereof). In yet further exemplary approaches, Re and R7 of Formula II may be a cyclic hydrocarbyl group and examples include cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, dimethyl cyclopentyl, methylcyclopentyl, dimethyl cyclopentyl, methylethylcyclopentyl, diethylcyclo- pentyl, methylcyclohexyl, dimethylcyclohexyl, methylethylcyclohexyl, diethylcyclohexyl, methylcycloheptyl, dimethylcycloheptyl, methylethyl-cycloheptyl, and / or di ethylcycloheptyl. In one embodiment, the amine salt of the phosphorodithioic acids or esters includes one or more of O,O-bis(2-ethylhexyl) phosphorodithioic amine salts of triethylamine, O,O-bis(isobutyl) phosphorodithioic amine salts of triethylamine, or mixtures thereof.

[0037] The amine salt of any phosphoric ester herein may be derived from a primary, secondary, or tertiary amine, or mixtures thereof. Exemplary amines suitable for the salt may be aliphatic, cyclic, aromatic or non-aromatic, but commonly is an aliphatic amine. Examples of suitable primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, bis- (2-ethylhexyl)amine, octylamine, and dodecyl-amine, and fatty amines such as n-octylamine, n- decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine or oleyamine. Examples of suitable secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine, methylethylamine, ethylbutylamine, N-methyl-l-amino-cyclo-hexane, and / or ethylamylamine. The secondary1663005438.1amines may also be cyclic amines such as piperidine, piperazine and morpholine. Examples of suitable tertiary amines may include triethyl amine, tri-n-butylamine, tri-n-octylamine, tridecylamine, tri-laurylamine, tri-hexadecylamine, and / or dimethyl-oleylamine.

[0038] In embodiments, the phosphorus-containing compound may be present in the liquid hydrocarbon in amounts of about 1 weight percent or less, about 0.5 weight percent or less, about 0.1 weight percent or less, or about 0.05 weight percent or less. In other embodiments, the phosphorus-containing compound may be in the liquid hydrocarbon in amounts of 0.005 to about 1 weight percent, about 0.008 to about 0.5 weight percent, about 0.01 to about 0.1 weight percent, or about 0.01 to about 0.08 weight percent, about 0.01 to about 0.05 weight percent.

[0039] Antifouling Composition

[0040] As noted above, the present application provides for a method of reducing, inhibiting, and / or cleaning-up fouling deposit formation from liquid hydrocarbons and maintaining a Temperature Difference Deviation ( TDD) within an anaerobic environment by combining a liquid hydrocarbon and an antifouling composition to reduce, inhibit, and / or clean-up deposits when the liquid hydrocarbon is heated to temperatures of about 100cC or greater in an anaerobic environment (in other embodiments, at least about 300°C or greater, at least about 400°C or greater, at least about 500°C or greater, or at least about 600°C or greater and, in other approaches, about 1000°C or less, about 900°C or less, about 800°C or less, or about 700°C or less or any other ranges between such noted temperatures) In approaches or embodiments, the antifouling composition includes (a) the above-described one or more linear or branched alkali or alkaline earth metal salts, (b) the above described one or more nitrogen-containing alkenyl succinimides, or combinations of (a) and (b), which are added or combined with a liquid hydrocarbon. The antifouling composition may optionally include the above-described phosphorus compounds as well.

[0041] In one embodiment, and when the antifouling composition includes both the abovedescribed one or more linear or branched alkali or alkaline earth metal salts and the abovedescribed one or more nitrogen-containing alkenyl succinimides, then the one or more linear or branched alkali or alkaline earth metal salts has a TBN as measured per ASTM D2896 of less than 250 mg KOH / g (preferably less than about 100 mg KOH / g, and most preferably, less than about 50 mg KOH / g) and the one or more nitrogen containing alkenyl succinimides has an1763005438.1alkenyl substituent thereof (preferably polyisobutylene) having a number average molecular weight of about 1600 g / mol or less (and preferably about 350 to about 1600 g / mol, and more preferably about 800 to about 1600 g / mol).

[0042] In another embodiment, and when the antifouling composition includes both the above-described one or more linear or branched alkali or alkaline earth metal salts and the above described one or more nitrogen-containing alkenyl succinimides, then the one or more linear or branched alkali or alkaline earth metal salts has a total base number (TBN) as measured per ASTM D2896 of about 250 mg KOH / g or more (preferably about 250 to about 500 mg KOH / g or other ranges of overbased metal salts described above) and the one or more nitrogencontaining alkenyl succinimides has an alkenyl substituent thereof (preferably polyisobutylene) having a weight average molecular weight greater than 1600 g / mol (preferably greater than 1600 to 5000 g / mol and most preferably about 1800 to about 2500 g / mol).

[0043] Optional Additives:

[0044] The methods and antifouling compositions herein may also include a number of optional additives combined with the select componentry discussed above and as needed to meet performance standards.

[0045] In approaches or embodiments herein, the antifouling composition may optionally include one or more thiadiazole compounds or hydrocarbyl-substituted derivatives. Examples of the thiadiazole compound that may be used include, but are not limited to, 2,5-dimercapto-l,3,4- thiadiazole, 2-mercapto-5-hydrocarbylthio-l,3,4-thiadiazole, 2-mercapto-5-hydrocarbyl dithio-1.3.4-thiadiazole, 2,5-bis(hydrocarbylthio)- 1,3,4-thiadiazole, or 2,5-bis(hydrocarbyl dithio)-1.3.4-thiadiazoles. The 1,3,4-thiadiazoles are generally synthesized from hydrazine and carbon disulfide by known procedures. See, for example, US 2,765, 289; US 2,749,311; US 2,760,933; US 2,850,453; US2,910,439; US 3,663,561; US 3,862,798; and US 3,840,549.

[0046] In approaches, the thiadiazole or derivative thereof includes one or more compounds having a structure of Formula III:(Formula III)1863005438.1wherein each R1 of Formula III is independently hydrogen or sulfur, each R2 of Formula III is independently an alkyl group, n is an integer of 0 or 1 and if R1 is hydrogen then the integer n of the adjacent R2 moiety is 0 and if R1 is sulfur then the n of the adjacent R2 moiety is 1, and with the proviso that at least one R1 is sulfur. In other approaches, the thiadiazole additive is a blend of compounds of Formula Illa and Formula Illb shown below:(Formula Illa) wherein within Formula Illa each integer n is 1, each R1 is sulfur, and each R2 is a C5 to C15 alkyl group, preferably a C8 to C12 alkyl group; and(Formula Illb) wherein within Formula Illb one integer n is 1 with an associated R2 group being a C5 to C15 alkyl group (preferably a C8 to C12 alkyl group) and the other integer n is 0 and with both R1 groups being sulfur. In some embodiments, the sulfur-providing additive includes a blend of Formula Illa and Illb with Formula Iva being a majority of the blend and in other approaches, the blend of Illa and Illb is about 75 to about 90 weight percent of Illa and about 10 to about 25 weight percent of Illb (or other ranges therewithin). In another approach, the sulfur-providing additive is a 2,5 dimercapto 1,3,4 thiadiazole including a blend of 2,5-bis-(nonyldithio)-l,3,4- thiadiazole (such as about 75 to about 90%) and 2,5-mono-(nonyldithio)-l,3,4-thiadiazole (such as about 10 to about 25%).

[0047] In yet other approaches, the antifouling compositions herein may also include one or more sulfur-containing compounds selected from sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, and / or sulfurized olefins (see, for example U.S. Pat. Nos. 2,995,569; 3,673,090; 3,703,504; 3,703,505; 3,796,661; 3,873,454 4,119,549;4,119,550; 4,147,640; 4,191,659; 4,240,958; 4,344,854; 4,472,306; and 4,711,736), dihydrocarbyl polysulfides (see for example U.S. Pat. Nos. 2,237,625; 2,237,627; 2,527,948; 2,695,316; 3,022,351; 3,308,166; 3,392,201; 4,564,709; and British 1,162,334), functionally- substituted dihydrocarbyl polysulfides (see for example U.S. Pat. No. 4,218,332), and63005438.1polysulfide olefin products (see for example U.S. Pat. No. 4,795,576). Other suitable examples include organo-sulfur compounds selected from sulfurized olefins, sulfur-containing amino heterocyclic compounds, ,5-dimercapto-l,3,4-thiadiazole, polysulfides having a majority of S3 and S4 sulfides, sulfurized fatty acids, sulfurized branched olefins, organic polysulfides, and mixtures thereof.

[0048] One example of sulfur-containing compound includes one or more polysulfides composed of one or more compounds represented by the formula: Ra-Sx-Rb where Raand Rb are hydrocarbyl groups each of which may contain 1 to 18, and in other approaches, 3 to 18 carbon atoms and x is may be in the range of from 2 to 8, and typically in the range of from 2 to 5, especially 3. In some approaches, x is an integer from 3 to 5 with about 30 to about 60 percent of x being an integer of 3 or 4. The hydrocarbyl groups can be of widely varying types such as alkyl, cycloalkyl, alkenyl, aryl, or aralkyl. Tertiary alkyl polysulfides such as di-tert-butyl trisulfide, and mixtures comprising di-tert-butyl trisulfide (e.g., a mixture composed principally or entirely of the tri, tetra-, and pentasulfides) may be used. Examples of other useful dihydrocarbyl polysulfides include the diamyl polysulfides, the dinonyl polysulfides, the didodecyl polysulfides, and the dibenzyl polysulfides.

[0049] Another example of sulfur-containing compounds included sulfurized isobutenes made by reacting an olefin, such as isobutene, with sulfur. In one embodiment, sulfurized isobutene (SIB), notably sulfurized polyisobutylene, typically has a sulfur content of from about 10 to about 55%, desirably from about 30 to about 50% by weight. A wide variety of other olefins or unsaturated hydrocarbons, e.g., isobutene dimer or trimer, may be used to form the sulfurized olefin extreme pressure agents. Various methods have been disclosed in the prior art for the preparation of sulfurized olefins. See, for example, U.S. Pat. No. 3,471,404 to Myers; U.S. Pat. No. 4,204,969 to Papay et al.; U.S. Pat. No. 4,954,274 to Zaweski et al.; U.S. Pat. No. 4,966,720 to DeGonia et al.; and U.S. Pat. No. 3,703,504 to Horodysky, et al, each of which his incorporated herein by reference.

[0050] In other approaches or embodiments, suitable sulfur compound may include one or more sulfurized polyolefin oligomer or polymer having a structure of Formula IV R-Sx-R-[Sx-R-Sx]n-R (Formula IV) wherein each R of Formula IV above is, independently, derived from an olefin (preferably, a C2 to C6 linear or branched carbon chain or hydrocarbyl group or other olefin as described below),2063005438.1x is an integer of at least 1 , and preferably an integer from 1 to 5 (or an integer of 2 to 4 or an integer of 2 to 3), and n is an integer such that the overall sulfurized polyolefin oligomer or polymer has a weight average molecular weight of about 300 to about 800, preferably about 500 to about 750, or more preferably about 600 to about 750. In approaches, the sulfurized polyolefin oligomer has about 30 to about 50 weight percent total sulfur, preferably, about 40 to about 50 weight percent total sulfur, and more preferably, about 40 to about 45 weight percent total sulfur. As discussed more below, the sulfurized polyolefin oligomer herein is made by a three-step process. Examples of such sulfur containing compounds are described further in US 11,873,461, which is incorporated herein by reference.

[0051] The first step of the process to form such a sulfurized polyolefin is the reaction of an olefin with a sulfur halide to form an adduct or an intermediate sulfurized olefin reaction product. Suitable olefins for this first reaction step may be any unsaturated aliphatic hydrocarbons, and in some approaches, are olefins having 2 to 18 carbon atoms, in other approaches, 2 to 12 carbons, or in further approaches, 2 to 6 carbons. Examples of suitable olefins include, but are not limited to, ethylene, propylene, isopropylene, 1 -butene, 2-butene, isobutene, 1-pentene, 2-pentene, 2-methyl-l -butene, 3 -methyl- 1 -butene, 2-methyl-2-butene, 1- hexene, 2-hexene, 3 -hexene, 2-methyl-l -pentene, 2-methyl-2-pentene, 2-ethyl-2-butene, neopentylene, hexane, octane, styrene, aco-diolefms, 1,5-hexadiene, 1,6-heptadiene, 1,7- octadiene, branched chain alpha-olefins, methyl-pentene, methyl-heptene, and the like olefins as well as mixtures thereof. Suitable olefins may also include branched olefins such as isobutene, 2-methyl-l -butene, 1 -methyl-2-butene, 2-methyl-2-pentene and the like as well as mixtures thereof. Preferably, the olefin is isobutylene.

[0052] Suitable sulfur halide reactants for preparing the adduct or the intermediate sulfurized olefin reaction product of the first reaction step may be selected from sulfur monochloride, sulfur dichloride, disulfur dibromide, sulfur dibromide, or mixtures thereof. Preferably, the sulfur halide is sulfur monochloride, which those of skill appreciate is S2CI2.

[0053] In approaches, the selected olefin may be added to the sulfur halide as a gas or liquid to form the adduct or the intermediate sulfurized olefin reaction product as a first step to form the extreme pressure additives herein. Preferably, the olefin is added beneath the surface of the sulfur halide as a gas. In practice, the selected olefin is added until the reaction with the sulfur halide stops as indicated, for instance, by loss of an exotherm. In approaches, about2163005438.10.4 to about 2 moles of olefin per each 0.3 to 0.8 moles of sulfur halide (such as sulfur monochloride) is suitable for the first reaction step of the methods herein.

[0054] In yet other approaches, the antifouling compositions herein may also include one or more phosphonate monoesters and, in particular, hydrocarbyl phosphonate monoesters. In some approaches, the hydrocarbyl phosphonate monoesters have the following Formula V(Formula V) wherein Ri of Formula V, the hydrocarbyl moiety, is a linear or branched C12 to C30 hydrocarbyl chain and R2, the monoester moiety, of Formula V is a linear or branched Cl to C4 alkyl group. In alternative approaches, R2 is a methyl or ethyl group.

[0055] Suitable phosphonates may also include primary alkyl acyclic hydrocarbyl phosphonates in which the primary alkyl group includes 1 to 4 carbon atoms and in which the acyclic hydrocarbyl group bonded to the phosphorus atom contains 12 to 30 carbon atoms and, in some approaches, is a linear hydrocarbyl group free of acetylenic unsaturation. In other approaches, the acyclic hydrocarbyl group includes 12 to 24 carbon atoms, and in yet further approaches, 12 to 20 carbon atoms.

[0056] Exemplary phosphonate compounds include methyl hydrocarbyl phosphonates, ethyl hydrocarbyl phosphonates, propyl hydrocarbyl phosphonates, butyl hydrocarbyl phosphonates, iso-butyl hydrocarbyl phosphonates, and wherein, in each case, the hydrocarbyl group is preferably linear, saturated, or contains one or more olefinic double bonds with each double bond preferably being an internal double bond. Other suitable compounds include those in which the hydrocarbyl group bonded to the phosphorus atom contains 16 to 20 carbon atoms or 18 to 20 carbon atoms. A particularly suitable phosphonate monoester compound may be ethyl octadecyl phosphonate or methyl octadecyl phosphonate. Other examples of suitable phosphonate monoesters include, but are not limited to, methyl triacontyl phosphonate, methyl triacontenyl phosphonate, methyl eicosyl phosphonate, methyl hexadecyl phosphonate, methyl hexadecenyl phosphonate, methyl tetracontenyl phosphonate, methyl hexacontyl phosphonate, methyl dodecyl phosphonate, methyl dodecenyl phosphonate, ethyl triacontyl phosphonate, ethyl triacontenyl phosphonate, ethyl eicosyl phosphonate, ethyl hexadecyl phosphonate, ethyl2263005438.1hexadecenyl phosphonate, ethyl tetracontenyl phosphonate, ethyl hexacontyl phosphonate, ethyl dodecyl phosphonate, ethyl dodecenyl phosphonate, and the like compounds, and mixtures thereof.

[0057] In yet other embodiments, the antifouling compositions herein may also include a phosphite, such as a phosphite diester, and in particular, a diester hydrogen phosphite. In some approaches, the phosphite diester may have the following Formula VI(Formula VI) wherein each R3 of Formula VI is independently selected form a Cl to a C30 hydrocarbyl chain. In some approaches, the phosphite may be a dialkyl or a dialkenyl hydrogen phosphite ester. The alkyl or alkenyl groups of the phosphite may independently contain from 1 to about 30 carbon atoms, in other approaches, about 10 to about 24 carbon atoms, and in yet further approaches, about 10 to about 20 carbon atoms. A number of dialkyl or dialkenyl phosphites may be suitable, such as lower to higher dialkyl / dialkenyl phosphites including the lower dialkyl phosphites of dimethyl, diethyl, dipropyl, dibutyl, dipentyl, and dihexyl phosphites and the higher alkenyl phophites of dioleyl, dicetyl, and distearyl phosphites. Also mixed alkyl / alkenyl phosphites, made from a mixture of alcohols, are useful in the present composition. Examples of mixtures of alcohols include ethyl and butyl alcohol, propyl and pentyl alcohol, and methyl and pentyl alcohol to suggest a few. Mixtures of those phosphites mentioned above may also be included in the compositions. A particularly useful phosphite is dioleyl hydrogen phosphite.

[0058] In yet other embodiments, the antifouling compositions herein may further include phosphonate diesters. In some approaches, the phosphonate diesters may have the following Formula VII(Formula VII) wherein R4 of Formula VII is a C l to C30 hydrocarbyl chain and each Rs of Formula VII is independently a Cl to CIO alkyl group and preferably a Cl to C4 alkyl group. In some embodiments, suitable phosphonate diesters may include O,O-di-(primary alkyl)acyclic2363005438.1hydrocarbyl phosphonates in which the primary alkyl groups are the same or different and each independently containing 1 to 4 carbon atoms and in which the acyclic hydrocarbyl group bonded to the phosphorus atom may contain 12 to 30 carbon atoms and is a linear hydrocarbyl group free of acetylenic unsaturation. Exemplary compounds include O,O-dimethyl hydrocarbyl phosphonates, 0,0-diethyl hydrocarbyl phosphonates, 0,0-dipropyl hydrocarbyl phosphonates, 0,0-dibutyl hydrocarbyl phosphonates, O,O-diiso-butyl hydrocarbyl phosphonates, and analogous compounds in which the two alkyl groups differ, such as, for example, O-ethyl-O- methyl hydrocarbyl phosphonates, O-butyl-O-propyl hydrocarbyl phosphonates, and O-butyl-O- isobutyl hydrocarbyl phosphonates, wherein in each case the hydrocarbyl group is linear and is saturated or contains one or more olefinic double bonds, each double bond preferably being an internal double bond. Suitable compounds include compounds in which both O,O-alkyl groups are identical to each other. Other suitable compounds include compounds in which the hydrocarbyl group bonded to the phosphorus atom contains 16 to 20 carbon atoms. A particularly suitable hydrocarbyl phosphonate diester is dimethyl octadecyl phosphonate. Other examples of suitable phosphonate diesters include, but are not limited to, dimethyl triacontyl phosphonate, dimethyl triacontenyl phosphonate, dimethyl eicosyl phosphonate, dimethyl hexadecyl phosphonate, dimethyl hexadecenyl phosphonate, dimethyl tetracontenyl phosphonate, dimethyl hexacontyl phosphonate, dimethyl dodecyl phosphonate, dimethyl dodecenyl phosphonate and the like, and combinations thereof.

[0059] In general terms, various embodiments of suitable antifouling compositions may include components in the relative ranges listed in the following table where the noted components are set relative to the amount of nitrogen-containing alkenyl succinimide used in the particular embodiment.

[0060] Table 1 A: Embodiments of Suitable Antifouling Compositions (wt%)

[0061] Table IB: Exemplary treat rates of various embodiments of Antifouling Compositions in Liquid hydrocarbons2463005438.1

[0062] The relative amounts of each component above represent the ratios of each component, based upon the weight in the liquid hydrocarbon to be treated. Additives used in formulating the compositions described herein may be blended into the liquid hydrocarbon individually or in various sub-combinations. However, it may be suitable to blend all of the components concurrently using a concentrate.DEFINITIONS

[0063] For purposes of this disclosure, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th Ed. Additionally, general principles of organic chemistry are described in "Organic Chemistry", Thomas Sorrell, University Science Books, Sausolito: 1999, and "March’s Advanced Organic Chemistry", 5th Ed., Ed.: Smith, M.B. and March, ., John Wiley & Sons, New York: 2001, the entire contents of which are hereby incorporated by reference.

[0064] As described herein, compounds may optionally be substituted with one or more substituents, such as are illustrated generally above, or as exemplified by particular classes, subclasses, and species of the disclosure.

[0065] Unless otherwise apparent from the context, the term “major amount” is understood to mean an amount greater than or equal to 50 weight percent, for example, from about 80 to about 98 weight percent relative to the total weight of the composition. As also used herein, the term “minor amount” is understood to mean an amount less than 50 weight percent relative to the total weight of the composition.

[0066] As used herein, the term "hydrocarbyl group" or "hydrocarbyl" is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of a molecule and having a predominantly hydrocarbon character. Examples of hydrocarbyl groups include: (1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic radical); (2) substituted hydrocarbon substituents, that is,2563005438.1substituents containing non-hydrocarbon groups which, in the context of the description herein, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxy); (3) hetero-substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this description, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Hetero-atoms include sulfur, oxygen, nitrogen, and encompass substituents such as pyridyl, furyl, thienyl, and imidazolyl. In general, no more than two, or as a further example, no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; in some embodiments, there will be no non-hydrocarbon substituent in the hydrocarbyl group.

[0067] As used herein the term "aliphatic" encompasses the terms alkyl, alkenyl, alkynyl, each of which being optionally substituted as set forth below.

[0068] As used herein, an "alkyl" group refers to a saturated aliphatic hydrocarbon group containing 1-12 (e.g., 1-8, 1-6, or 1-4) carbon atoms. An alkyl group can be straight or branched. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-heptyl, or 2-ethylhexyl. An alkyl group can be substituted (i.e., optionally substituted) with one or more substituents such as halo, phospho, cycloaliphatic [e.g., cycloalkyl or cycloalkenyl], heterocycloaliphatic [e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl], nitro, cyano, amido [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl) carbonylamino, (heterocycloalkylalkyl) carbonylamino, heteroarylcarbonylamino, heteroaralkyl carbonylamino alkylaminocarbonyl, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, arylaminocarbonyl, or heteroarylaminocarbonyl], amino [e.g., aliphaticamino, cycloaliphatic amino, or heterocycloaliphaticamino], sulfonyl [e.g., aliphatic-SCh-], sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamide, oxo, carboxy, carbamoyl, cycloaliphaticoxy, heterocyclo aliphaticoxy, aryloxy, heteroaryl oxy, aralkyloxy, heteroarylalkoxy, alkoxycarbonyl, alkyl carbonyloxy, or hydroxy. Without limitation, some examples of substituted alkyls include carboxyalkyl (such as HOOC-alkyl, alkoxycarbonylalkyl, and alkylcarbonyloxyalkyl), cyanoalkyl, hydroxyalkyl, alkoxyalkyl, acylalkyl, aralkyl, (alkoxyaryl)alkyl, (sulfonylamino) alkyl (such as (alkyl-SC>2-amino)alkyl), aminoalkyl, amidoalkyl, (cycloaliphatic)alkyl, or2663005438.1haloalkyl.

[0069] As used herein, an "alkenyl" group refers to an aliphatic carbon group that contains 2- 8 (e.g., 2-12, 2-6, or 2-4) carbon atoms and at least one double bond. Like an alkyl group, an alkenyl group can be straight or branched. Examples of an alkenyl group include, but are not limited to allyl, isoprenyl, 2-butenyl, and 2-hexenyl. An alkenyl group can be optionally substituted with one or more substituents such as halo, phospho, cycloaliphatic [e.g., cycloalkyl or cycloalkenyl], heterocycloaliphatic [e.g., heterocycloalkyl or hetero cycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic) carbonyl, (cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl], nitro, cyano, amido [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (hetero cycloalkyl) carbonylamino, (heterocyclo alkylalkyl) carbonylamino, heteroarylcarbonylamino, heteroaralkylcarbonylamino alkylamino carbonyl, cycloalkylaminocarbonyl, hetero cyclo alkyl ami nocarbonyl, aryl ami nocarbonyl, or heteroarylaminocarbonyl], amino [e.g., aliphaticamino, cycloaliphaticamino, heterocyclo aliphaticamino, or aliphaticsulfonylamino], sulfonyl [e.g., alkyl-SCh- , cycloaliphatic-SCh-, or aryl-SCh-], sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamide, oxo, carboxy, carbamoyl, cycloaliphaticoxy, heterocycloaliphaticoxy, aryloxy, heteroaryloxy, aralkyloxy, heteroaralkoxy, alkoxycarbonyl, alkylcarbonyloxy, or hydroxy. Without limitation, some examples of substituted alkenyls include cyanoalkenyl, alkoxyalkenyl, acylalkenyl, hydroxyl alkenyl, aralkenyl, (alkoxyaryl) alkenyl, (sulfonylamino)alkenyl (such as (alkyl-SCh-amino) alkenyl), aminoalkenyl, amidoalkenyl, (cycloaliphatic)alkenyl, or haloalkenyl.

[0070] As used herein, an "alkynyl" group refers to an aliphatic carbon group that contains 2- 8 (e.g., 2-12, 2-6, or 2-4) carbon atoms and has at least one triple bond. An alkynyl group can be straight or branched. Examples of an alkynyl group include, but are not limited to, propargyl and butynyl. An alkynyl group can be optionally substituted with one or more substituents such as aroyl, heteroaroyl, alkoxy, cycloalkyloxy, heterocycloalkyloxy, aryloxy, heteroaryloxy, aralkyl oxy, nitro, carboxy, cyano, halo, hydroxy, sulfo, mercapto, sulfanyl [e.g., aliphaticsulfanyl or cycloaliphaticsulfanyl], sulfinyl [e.g., aliphaticsulfinyl or cycloaliphaticsulfinyl], sulfonyl [e.g., aliphatic-SCh-, aliphaticamino-SCh-, or cycloaliphatic-SCh-], amido [e.g., aminocarbonyl, alkylaminocarbonyl, alkylcarbonylamino, cyclo alkylaminocarbonyl, heterocycloalkylaminocarbonyl, cycloalkylcarbonylamino, arylamino carbonyl, aryl carbonyl ami no, aralkylcarbonylamino, (heterocycloalkyl) carbonylamino, (cycloalkylalkyl)2763005438.1carbonylamino, heteroaralkylcarbonylamino, heteroaryl carbonylamino or heteroaryl amino carbonyl], urea, thiourea, sulfamoyl, sulfamide, alkoxycarbonyl, alkyl carbonyloxy, cyclo aliphatic, heterocycloaliphatic, aryl, heteroaryl, acyl [e.g., (cycloaliphatic) carbonyl or (hetero cyclo aliphatic)carbonyl], amino [e.g., aliphaticamino], sulfoxy, oxo, carboxy, carbamoyl, (cycloaliphatic)oxy, (heterocyclo aliphatic) oxy, or (heteroaryl)alkoxy.

[0071] As used herein, an "amino" group refers to -NRXRYwherein each of Rxand R is independently hydrogen, alkyl, cycloakyl, (cycloalkyl)alkyl, aryl, aralkyl, heterocycloalkyl, (heterocycloalkyl)alkyl, heteroaryl, carboxy, sulfanyl, sulfinyl, sulfonyl, (alkyl)carbonyl, (cycloalkyl)carbonyl, ((cycloalkyl)alkyl)carbonyl, arylcarbonyl, (aralkyl)carbonyl, (heterocyclo alkyl) carbonyl, ((heterocycloalkyl)alkyl)carbonyl, (heteroaryl)carbonyl, or (heteroaralkyl) carbonyl, each of which being defined herein and being optionally substituted. Examples of amino groups include alkylamino, dialkylamino, or arylamino. When the term "amino" is not the terminal group (e.g., alkylcarbonylamino), it is represented by -NRX-. Rxhas the same meaning as defined above.

[0072] As used herein, a "cycloalkyl" group refers to a saturated carbocyclic mono- or bicyclic (fused or bridged) ring of 3-10 (e.g., 5-10) carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbomyl, cubyl, octahydro-indenyl, decahydro-naphthyl, bicyclo[3.2.1]octyl, bicyclo[2.2.2] octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2.]decyl, bicyclo[2.2.2]octyl, adamantyl, or ((aminocarbonyl)cycloalkyl)cycloalkyl.

[0073] As used herein, a "heterocycloalkyl" group refers to a 3-10 membered mono- or bicylic (fused or bridged) (e.g., 5- to 10-membered mono- or bicyclic) saturated ring structure, in which one or more of the ring atoms is a heteroatom (e.g., N, O, S, or combinations thereof). Examples of a heterocycloalkyl group include piperidyl, piperazyl, tetrahydropyranyl, tetrahydrofuryl, 1,4-dioxolanyl, 1,4-dithianyl, 1,3-dioxolanyl, oxazolidyl, isoxazolidyl, morpholinyl, thiomorpholyl, octahydrobenzofuryl, octahydrochromenyl, octahydrothio chromenyl, octahydroindolyl, octahydropyrindinyl, decahydroquinolinyl, octahydrobenzo[Z>] thiopheneyl, 2-oxa-bicyclo[2.2.2]octyl, l-aza-bicyclo[2.2.2]octyl, 3-aza-bicyclo[3.2.1]octyl, and 2,6-dioxa-tricyclo[3.3.1.0]nonyl. A monocyclic heterocycloalkyl group can be fused with a phenyl moiety to form structures, such as tetrahydroisoquinoline, which would be categorized as heteroaryls.2863005438.1

[0074] A "heteroaryl" group, as used herein, refers to a monocyclic, bicyclic, or tricyclic ring system having 4 to 15 ring atoms wherein one or more of the ring atoms is a heteroatom (e.g., N, O, S, or combinations thereof) and in which the monocyclic ring system is aromatic or at least one of the rings in the bicyclic or tricyclic ring systems is aromatic. A heteroaryl group includes a benzofused ring system having 2 to 3 rings. For example, a benzofused group includes benzo fused with one or two 4 to 8 membered heterocycloaliphatic moi eties (e.g., indolizyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[Z>]furyl, benzo[Z>]thiophenyl, quinolinyl, or isoquinolinyl). Some examples of heteroaryl are pyridyl, IH-indazolyl, furyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, tetrazolyl, benzofuryl, isoquinolinyl, benzthiazolyl, xanthene, thioxanthene, phenothiazine, dihydroindole, benzo[l,3]dioxole, benzo[b] furyl, benzo[b] thiophenyl, indazolyl, benzimidazolyl, benzthiazolyl, puryl, cinnolyl, quinolyl, quinazolyl, cinnolyl, phthalazyl, quinazolyl, quinoxalyl, isoquinolyl, 4H-quinolizyl, benzo-1,2,5- thiadiazolyl, or 1,8-naphthyridyl.

[0075] Without limitation, monocyclic heteroaryls include furyl, thiophenyl, 2H-pyrrolyl, pyrrolyl, oxazolyl, thazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,3,4-thiadiazolyl, 2H-pyranyl, 4-H-pranyl, pyridyl, pyridazyl, pyrimidyl, pyrazolyl, pyrazyl, or 1,3,5-triazyl. Monocyclic heteroaryls are numbered according to standard chemical nomenclature.

[0076] Without limitation, bicyclic heteroaryls include indolizyl, indolyl, isoindolyl, 3H- indolyl, indolinyl, benzo[Z>]furyl, benzo[6]thiophenyl, quinolinyl, isoquinolinyl, indolizinyl, isoindolyl, indolyl, benzo[Z>]furyl, bexo[Z>]thiophenyl, indazolyl, benzimidazyl, benzthiazolyl, purinyl, 4H-quinolizyl, quinolyl, isoquinolyl, cinnolyl, phthalazyl, quinazolyl, quinoxalyl, 1,8- naphthyridyl, or pteridyl. Bicyclic heteroaryls are numbered according to standard chemical nomenclature.

[0077] As used herein, the term “treat rate” refers to the weight percent of a component in the liquid hydrocarbon.

[0078] The weight average molecular weight (Mw) and the number average molecular weight (Mn) may be determined with a gel permeation chromatography (GPC) instrument obtained from Waters or the like instrument and the data processed with Waters Empower Software or the like software. The GPC instrument may be equipped with a Waters Separations Module and Waters Refractive Index detector (or the like optional equipment). The GPC operating conditions may include a guard column, 4 Agilent PLgel columns (length of 300x7.5 mm; particle size of 5 p,2963005438.1and pore size ranging from 100-10000 A) with the column temperature at about 40°C. Unstabilized HPLC grade tetrahydrofuran (THF) may be used as solvent, at a flow rate of 1.0 mL / min. The GPC instrument may be calibrated with commercially available poly(methyl methacrylate) (PMMA) standards having a narrow molecular weight distribution ranging from 960 - 1,568,000 g / mol. The calibration curve can be extrapolated for samples having a mass less than 500 g / mol. Samples and PMMA standards can be in dissolved in THF and prepared at concentration of 0.1 to 0.5 wt. % and used without filtration. GPC measurements are also described in US 5,266,223, which is incorporated herein by reference. The GPC method additionally provides molecular weight distribution information; see, for example, W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography,” John Wiley and Sons, New York, 1979, also incorporated herein by reference.EXAMPLES

[0079] A better understanding of the present disclosure and its many advantages may be clarified with the following examples. The following examples are illustrative and not limiting thereof in either scope or spirit. Those skilled in the art will readily understand that variations of the components, methods, steps, and devices described in these examples can be used. Unless noted otherwise or apparent from the context of discussion in the Examples below and throughout this disclosure, all percentages, ratios, and parts noted in this disclosure are by weight. Reference to any standardized test method, unless apparent from the context of its use herein, refers to the version publicly available at the time of this disclosure.

[0080] EXAMPLE 1

[0081] This example uses a fouling test apparatus that determines the performance of the chemistry in conditions that closely approximate those experienced in real world heat exchange. The evaluation of this example used a heated tube that approximates the oil heat transfer interface where oil and the antifoulant chemistry are passed over the tube in a repeated fashion. The tube can be measured for fouling performance in a number of ways including measuring the amount of energy required to maintain a steady temperature, the change in temperature from tube inlet to outlet, or by physically measuring the amount of deposit accumulated. The evaluations of this Example measured the accumulated deposits.3063005438.1

[0082] The measurements conducted for this Example used a Falex FT2 thermal fouling apparatus (Falex Corporation, Illinois, USA). This device included a 316 stainless steel tube that was heated to about 450°C under a pressure of about 200 psi with a flow rate of the liquid hydrocarbon under evaluation of about 4 mL / min for about 6 hours. The amounts of deposits were measured for each experiment at the end of the 6 hour test. Table 2 below details the results obtained showing that a commercially available comparative example in Fluid 2 was able to reduce the fouling amount observed as compared to an untreated liquid hydrocarbon (e.g., Fluid 1). Fluid 2 included an antifoulant composition of an alkaline earth alkyl phosphonate phenate sulfide, an alkyl phosphonate phenate sulfide, an amine neutralized alkyl phosphonate, and / or mixtures thereof (Hi TEC® 686) and as described, for example, in US 4,828,674 or US 5,314,643. Fluid 3 included only a nitrogen-containing alkenyl succinimide in the antifouling composition, but did not provide performance better than the control fluid 2 in terms of deposits. Fluid 4 included only an alkali or alkaline earth metal salts as the antifouling composition, but also did not provide performance better than the control in terms of deposits. In contrast, by mixing the components of fluid 3 and 4, a large synergistic response is observed in terms of deposits in fluid 5. The addition of a third component enables an even further synergy in the form of fluid 6.

[0083] Table 2: Test results obtained using Falex FT2 thermal fouling apparatus.

[0084] The fluid compositions and treat rates are further detailed in Table 3. The nitrogencontaining alkenyl succinimide used in the evaluations was a 1300 number average molecular weight polyisobutylene-substituted succinimide dispersant.

[0085] The alkali or alkaline earth metal salt used in the evaluations was a low-based calcium sulfonate detergent having a TBN of 0 to 50 (ASTM D2896), and the phosphorodithioic acid,3163005438.1ester, or salt used in the evaluations was phosphorodithioic acid mixed with O,O-bis(2- ethylhexyl and iso-butyl) esters with triethylamine (CAS number: 68909-91-1).

[0086] Table 3: Fluid Compositions

[0087] As shown in Table 2 and 3, when the nitrogen-containing alkenyl succinimide or the alkali or alkaline earth metal salts were used individually as the antifouling composition, neither achieved fouling improvement in the context of deposits better than the control using the known HiTEC® 686 Additive. Thus, it was not expected that using combinations of such additives would achieve dramatically improved fouling performance over the control in terms of deposit control.

[0088] EXAMPLE 2

[0089] Further evaluations of antifouling compositions were conducted using the Falex FT2 thermal fouling apparatus (Falex Corporation, Illinois, USA) of Example 1 to evaluate heat transfer. In this Example, heat transfer was evaluated via a Temperature Difference Deviation (TDD) from the start to the end of the evaluation to determine the amount of temperature change across the tube from the start to the end of the testing. A negative TDD reflected poor heat transfer, deposit formations, or fouling of the tube. A zero TDD reflected a constant ability to provide heat transfer or an ability to keep the tube clean. A positive TDD reflected an improved heat transfer and / or the ability to clean-up the tube.

[0090] The Temperature Difference Deviation (TDD) as used herein was determined as follows (and example is provided in FIG. 1): (1) the difference between the inlet and the outlet temperatures at the start of testing was measured to determine a Delta Temp (Start), which was determined as an average of the Delta Temp (Start) temperatures over a 20 minute time span centered at 30 minutes into the testing. (2) the difference between the inlet and the outlet temperatures at the end of testing was measured to determine a Delta Temp (End), which was an3263005438.1average of the Delta Temp (Start) temperatures over a 20 minute time ending at 6 hours into the testing. The Temperature Difference Deviation (TDD) in °C was (2) the Delta Temp (End) subtracted from (1) the Delta Temp (Start).

[0091] In this Example, the following additives were evaluated in the antifouling composition and added to a liquid hydrocarbon:(A) Succinimide (1): 1300 number average molecular weight polyisobutylene-substituted succinimide(B) Succinimide (2): 2100 number average molecular weight polyisobutylene-substituted succinimide(C) Succinimide (3): 950 number average molecular weight polyisobutylene-substituted succinimide(D) Succinimide (4): 1600 number average molecular weight polyisobutylene-substituted succinimide(E) Metal Salt (1): low-based calcium sulfonate having a TBN of 0 to 50 (ASTM D2896) and having about 2 to about 3 weight percent calcium(F) Metal Salt (2): overbased calcium sulfonate having a TBN of about 300 to about 320 (ASTM D2896) and having about 11 to about 12 weight percent calcium(G) Metal Salt (3): overbased calcium phenate having a TBN of 250 (ASTM D2896) and having about 9 to about 10 weight percent calcium(H) Metal Salt (4): low-based calcium phenate having a TBN of about 153 (ASTM D2896) and about 5 to about 6 weight percent calcium(I) Phosphorus (1): phosphorodithioic acid mixed with O,O-bis(2-ethylhexyl and isobutyl) esters with tri ethylamine (CAS number: 68909-91-1).

[0092] The antifouling compositions of Table 4 below were compared to a liquid hydrocarbon alone (API Group I base soil , AP / E Core 150) and then the liquid hydrocarbon with the Hi TEC® 686 Additive (0.1 wt%) of Example 1. The testing was consistent to that described in Example 1 and utilized the Falex FT2 thermal fouling apparatus with a 316 stainless steel tube that was heated to about 450°C under a pressure of about 200 psi with a flow rate of the liquid hydrocarbon under evaluation (API Group I base oil, AP / E Core 150) of about 4 mL / min for about 6 hours. The Temperature Difference Deviation (TDD), as defined above, was calculated for each antifouling composition (with a minimal detectable difference of 0.09).3363005438.1Table 4 below includes the amount of additive (wt%) in the liquid hydrocarbon (API Group I, AP / E Core 150).

[0093] Table 4: Antifouling Compositions (wt%)

[0094] For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0095] It is to be understood that each component, compound, substituent or parameter disclosed herein is to be interpreted as being disclosed for use alone or in combination with one or more of each and every other component, compound, substituent or parameter disclosed herein.

[0096] It is further understood that each range disclosed herein is to be interpreted as a disclosure of each specific value within the disclosed range that has the same number of3463005438.1significant digits. Thus, for example, a range from 1 to 4 is to be interpreted as an express disclosure of the values 1, 2, 3 and 4 as well as any range of such values.

[0097] It is further understood that each lower limit of each range disclosed herein is to be interpreted as disclosed in combination with each upper limit of each range and each specific value within each range disclosed herein for the same component, compounds, substituent or parameter. Thus, this disclosure to be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range. That is, it is also further understood that any range between the endpoint values within the broad range is also discussed herein. Thus, a range from 1 to 4 also means a range from 1 to 3, 1 to 2, 2 to 4, 2 to 3, and so forth.

[0098] Furthermore, specific amounts / values of a component, compound, substituent or parameter disclosed in the description or an example is to be interpreted as a disclosure of either a lower or an upper limit of a range and thus can be combined with any other lower or upper limit of a range or specific amount / value for the same component, compound, substituent or parameter disclosed elsewhere in the application to form a range for that component, compound, substituent or parameter.

[0099] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or can be presently unforeseen can arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they can be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.3563005438.1

Claims

CLAIMSWhat is claimed is:

1. A method of reducing or inhibiting fouling deposit formation from liquid hydrocarbons within an anaerobic environment, the method comprising combining a liquid hydrocarbon and an antifouling composition to reduce or inhibit deposits when the liquid hydrocarbon is heated to temperatures of about 100°C or greater in an anaerobic environment and wherein the antifouling composition includes (a) one or more linear or branched alkali or alkaline earth metal salts, (b) one or more nitrogen-containing alkenyl succinimides, or combinations of (a) and (b).

2. The method of claim 1, wherein the antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts, and wherein the one or more linear or branched alkali or alkaline earth metal salts is one or more linear or branched alkyl benzene or toluene sulfonates.

3. The method of claim 2, wherein the linear or branched alkyl benzene or toluene sulfonate has a total base number (TBN) as measured per ASTM D2896 of less than 250 mg KOH / g.

4. The method of claim 2, wherein the linear or branched alkyl benzene or toluene sulfonate has a TBN as measured per ASTM D2896 of about 100 mg KOH / g or less.

5. The method of any preceding claim, wherein the one or more linear or branched alkali or alkaline earth metal salts provide up to about 500 ppm of calcium to the liquid hydrocarbon.

6. The method of any preceding claim, wherein the antifouling composition includes (b) the one or more nitrogen-containing alkenyl succinimides, and wherein the one or more nitrogen-containing alkenyl succinimides is a polyisobutylene succinimide and wherein the3663005438.1polyisobutylene substituent thereof has a number average molecular of about 500 to about 5,000 g / mol.

7. The method of any preceding claim, wherein the nitrogen-containing alkenyl succinimide is derived by reacting polyisobutylene with an acylating agent to form an acylated polyisobutylene and reacting the acylated polyisobutylene with a nitrogen source.

8. The method of claim 7, wherein the acylating agent is fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid, dimethylmaleic acid, hexylmaleic acid, anhydrides thereof, or combinations thereof.

9. The method of any of claims 7 to 8, wherein the nitrogen source is ammonia, a polyalkylene polyamine, polyethylene polyamines having 5 or an average of 5 nitrogen atoms, diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylamine hexamine (PEHA), or combinations thereof.

10. The method of any of claims 7 to 9, wherein the nitrogen-containing alkenyl succinimide is post-treated with boron, boron compounds, urea, thiourea, dimercapto thiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compound or combinations thereof.

11. The method of any of claims 7 to 10, wherein the poly isobutylene (PIB) has greater than about 50 mol percent of terminal double bonds.

12. The method of any preceding claim, wherein antifouling composition includes the (a) one or more linear or branched alkali or alkaline earth metal salts and the (b) one or more nitrogen-containing alkenyl succinimides.

13. The method of claim 12, wherein the one or more linear or branched alkali or alkaline earth metal salts has a TBN as measured per ASTM D2896 of less than 250 mg KOH / g3763005438.1and the one or more nitrogen-containing alkenyl succinimides has an alkenyl substituent thereof having a number average molecular weight of about 1600 g / mol or less.

14. The method of claim 12, wherein the one or more linear or branched alkali or alkaline earth metal salts has a total base number (TBN) as measured per ASTM D2896 of about 250 mg KOH / g or more and the one or more nitrogen-containing alkenyl succinimides has an alkenyl substituent thereof having a weight average molecular weight greater than 1600 g / mol.

15. The method of any preceding claim, wherein the antifouling composition further includes a phosphorus containing compound selected from thiophosphates, dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus- containing carboxylic esters, ethers, or amine salts thereof, or mixtures thereof.

16. The method of claim 15, wherein the phosphorus-containing compound is a phosphorodithioic acid, ester, and / or salt thereof.

17. The method of claim 15, wherein the phosphorus-containing compound is a phosphorodithioc acid, ester, or salt thereof derived from one of ethylhexanol, iso-propanol, isobutanol, or combinations thereof.

18. The method of claim 17, wherein the phosphorodithioic acid, ester, or salt thereof includes one or more of a phosphorodithioic acid including O,O-bis(2-ethylhexyl and iso-butyl) esters with tri ethyl amine.

19. An antifouling composition suitable for use with liquid hydrocarbons, the antifouling comprising: (a) one or more linear or branched alkali or alkaline earth metal salts; (b) one or more nitrogen-substituted alkenyl succinimides; and (c) optionally one or more phosphorus containing compounds.3863005438.

120. The antifouling composition of claim 19, wherein the antifouling composition is of any claim 1 to 18.3963005438.1

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