Cationic saccharide polymers and methods for use thereof

Abstract

Cationic saccharide polymers may be utilized for mitigating corrosion and / or removing organic pollutants from an aqueous fluid. The cationic saccharide polymers may comprise a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer. A composition comprising the cationic saccharide polymer may be contacted with a metal surface, the metal surface may be exposed to corrosive conditions, and the composition may be allowed to decrease an extent of corrosion of the metal surface. For removal of organic pollutants, an aqueous fluid containing one or more organic pollutants may be contacted with the composition, and an at least partially remediated aqueous fluid having lower concentration of at least one of the one or more organic pollutants may be obtained.

Description

Atty. Docket No.: 075716-000166CATIONIC SACCHARIDE POLYMERS AND METHODS FOR USE THEREOFFIELD

[0001] The present disclosure generally relates to surfactants and, more particularly, methods for use of cationic saccharide polymers as surfactants.BACKGROUND

[0002] Amphiphilic compounds having both hydrophobic and hydrophilic regions within their molecular structure are commonly referred to as "surfactants" or "surfactant compounds." By virtue of their molecular structure, surfactants tend to lower the surface tension at an interface between two components. Other properties impacted by surfactants may include, for example, surface wetting characteristics, emulsification / de-emulsification performance, foaming tendency, and the like.

[0003] Surfactants are utilized in a number of consumer and industrial products and applications. Common uses of surfactants may include, for example, facilitating dissolution or emulsification of otherwise insoluble materials, promoting foaming or detergency, and the like. Other applications of surfactants include, for example, providing resistance to corrosion and promoting removal of organic pollutants from aqueous fluids.

[0004] Although surfactants provide a number of useful benefits, including, but not limited to those discussed above, there are downsides associated with a number of conventional surfactants. Many conventional surfactants are derived from petroleum products and can present toxicity issues as they accumulate in the environment due to their poor biodegradability. Accumulation of conventional surfactants in aquatic environments and toxicity to aquatic life can be particularly impactful. Additionally, the performance of conventional surfactants may become less effective under challenging conditions such as, for example, high salinity, high temperature, or pH extremes.

[0005] Surfactants are commonly used during the recovery of hydrocarbon resources, such as oil and gas, from subterranean formations. Although surfactants may be utilized during various types of oilfield operations, the challenging conditions commonly encountered in subterranean formationsAtty. Docket No.: 075716-000166and in produced hydrocarbon fluids may lead to inadequate performance of the surfactant. Moreover, the potential for environmental damage during oilfield operations may require careful selection of conventional surfactants suitable for a given situation.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Not applicable.DETAILED DESCRIPTION

[0007] The present disclosure generally relates to surfactants and, more particularly, methods for use of cationic saccharide polymers as surfactants.

[0008] Although surfactants find wide use in consumer and industrial products and applications, there are limitations associated with many types of conventional surfactants. Included among these limitations are environmental accumulation, limited biodegradability, and inadequate performance under challenging use conditions.

[0009] The present disclosure addresses the foregoing issues and provides related advantages as well. In particular, the present disclosure describes compositions comprising cationic surfactants that may exhibit improved performance and other advantageous features compared to conventional surfactants. The cationic surfactants are formed, in part, from biodegradable materials and may provide a lower environmental burden than do conventional surfactants.

[0010] In particular, the cationic surfactants of the present disclosure are formed through halohydrin-mediated functionalization of a saccharide polymer. The term "saccharide polymer" is inclusive of both saccharide oligomers and polysaccharides. A wide variety of parent saccharide polymers may be selected for reaction with a halohydrin in order to tailor the surfactancy properties of the resulting cationic saccharide polymer. The halohydrin may introduce a cationic functionality, such as a quaternary ammonium group. The alkyl substituents defining the quaternary ammonium group may likewise be selected to tailor the surfactancy properties of the resulting cationic saccharide polymers in a desired manner. The amount of quaternary ammonium groups incorporated within the cationic saccharide polymers may likewise be adjustedAtty. Docket No.: 075716-000166to facilitate further tailoring of the surfactant performance in various applications.

[0011] In addition to the advantages conveyed by the chemical structure of the cationic saccharide polymers, as well as the ability for ready tailoring thereof, the cationic saccharide polymers may further exhibit improved performance relative to conventional surfactants in at least some applications. As non-limiting examples, the cationic saccharide polymers disclosed herein may provide enhanced corrosion inhibition performance and promote increased removal of organic pollutants, such as perfluoroalkyl substances, relative to that afforded by conventional surfactants, such as cetyltrimethylammonium bromide (CTAB). Additional description of applications in which the cationic saccharide polymers of the present disclosure may provide advantaged performance are discussed in further detail hereinbelow.

[0012] Accordingly, compositions of the present disclosure may comprise a cationic saccharide polymer that is a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer, such as a maltodextrin or other dextrin compound. Halohydrins are a class of organic compounds having a halogen atom and a hydroxyl group located on adjacent carbon atoms. Halohydrins (or the corresponding epoxide) may functionalize maltodextrins and other saccharide polymers via a nucleophilic substitution reaction. Quaternary ammonium halohydrins suitable for use in functionalizing a parent saccharide polymer to produce a cationic saccharide polymer according to the present disclosure may have a structure represented by Compound 1.OH R1U X NR2^R3Compound 1In Compound 1, X is a halide (e.g., Cl, Br, or I; preferably Cl, in which case the halohydrin is a chlorohydrin), A is a C1-C10 alkylene group, and R1, R2, and R3are independently C1-C30 alkyl groups or C1-C18 alkyl groups. Without being bound by theory or mechanism, the corresponding epoxide (e.g.,Atty. Docket No.: 075716-000166Compound 1A) is believed to form under nucleophilic substitution conditions, followed by nucleophilic attack of a hydroxyl group at the less-hindered carbon of the epoxide.R1Compound 1AThus, in some embodiments, the corresponding epoxide may be utilized directly to promote functionalization of a saccharide polymer in a similar manner.

[0013] Alkylene groups are divalent hydrocarbon groups. Suitable alkylene groups may include, but are not limited to, methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-nonylene, 1,8-octylene, 1,9-nonylene, and 1,10-decylene. Optionally, a C2-C10 alkylene group may contain a branch, such as a methyl or ethyl branch. Optionally, a C2-C10 alkylene group may contain a heteroatom such as an oxygen atom or a nitrogen atom that takes the place of a carbon atom in the corresponding parent alkylene group. In some examples, the alkylene group is a methylene group (A is a Cl alkylene group).

[0014] The C1-C30 alkyl groups defining R1, R2, and R3in the halohydrin (or the corresponding epoxide) and in the corresponding cationic saccharide polymers may be straight-chain or branched, or cyclic or non-cyclic. Optionally, any C2-C30 alkyl groups may contain a heteroatom such as an oxygen atom or a nitrogen atom that takes the place of a carbon atom in the corresponding parent alkyl group. In some examples, each of R1, R2, and R3may be selected from among straight-chain C1-C30 alkyl groups or C1-C18 alkyl groups. In some examples, R1, R2, and R3are each a Cl alkyl group. In some examples, at least one of R1, R2, and R3is a straight-chain C8-C18 alkyl group. In some examples, R1may be a straight-chain C1-C18 alkyl group or C8-C18 alkyl group and R2and R3may be a Cl alkyl group (z'.e., a methyl group).

[0015] In some examples, the halohydrin has a structure represented by Compound 2.Atty. Docket No.: 075716-000166Compound 2In Formula 2, R1is a straight-chain C1-C30 alkyl group, a C1-C18 alkyl group, or a C8-C18 alkyl group. The corresponding epoxide (structure not shown) may form as an intermediate during nucleophilic substitution or be used directly for functionalizing the saccharide polymer.

[0016] Parent saccharide polymers that may be functionalized with a quaternary ammonium halohydrin to produce a cationic saccharide polymer are not considered to be particularly limited. The parent saccharide polymer may be a polysaccharide or a dextrin compound. Suitable polysaccharides may include, but are not limited to, dextran, guar, scleroglucan, welan, xanthan, schizophyllan, levan, chitosan, and cellulose. The foregoing polysaccharides each have polymer backbones that are distinguished by a characteristic arrangement of glycosidic bonds between adjacent monosaccharide units. Many of the foregoing polysaccharides are branched, although some are substantially unbranched or not heavily branched. Dextran, for example, is characterized by having predominantly a(l,6) glycosidic bonds between adjacent glucose units (monomers), with a limited number of glucose side chains linked to the main polymer backbone via a(l,3) glycosidic bonds. Depending on the biological source, the extent of branching may vary considerably in dextran and other polysaccharides. In any embodiment here, the cationic saccharide polymer may be formed from dextran.

[0017] Formula 3 below shows the structural formula of a parent dextran before functionalization with a quaternary ammonium halohydrin. The glucose units are linked together along the main polysaccharide backbone via a(l,6) glycosidic bonds. Variable 'x' may range from about 5000 to about 300,000. In addition, multiple side chain glucose units may be linked to the main polysaccharide backbone via a(l,3) glycosidic bonds. The a(l,3) glycosidic bonds are distributed randomly upon the main polysaccharide backbone and are not depicted in Formula 3 in the interest of clarity.Atty. Docket No.: 075716-000166CH2OHOH Formula 3Any hydroxyl group of the polysaccharide may undergo functionalization with the quaternary ammonium halohydrin. The cationic functional groups introduced by the quaternary ammonium halohydrin may be distributed randomly throughout the polysaccharide at loading levels described further herein.

[0018] In illustrative embodiments, the pre-functionalization molecular weight of suitable dextrans may range from about 1 million and about 50 million. In more specific embodiments, suitable dextrans for undergoing functionalization with a quaternary ammonium halohydrin according to the present disclosure may have a pre-functionalization molecular weight ranging of about 1 million to about 5 million, or about 3 million to about 10 million, or about 5 million to about 10 million, or about 10 million to about 20 million, or about 20 million to about 30 million, or about 30 million to about 40 million, or about 40 million to about 50 million. The molecular weights may represent a viscosity average molecular weight measurement method.

[0019] Dextrin compounds typically contain a linear arrangement of saccharide monomers (glucose units), in which the number of glycosidically linked glucose units is much lower than in the related polysaccharides. Maltodextrins are an illustrative type of dextrin compound. Parent maltodextrins are available in a range of oligomer sizes (e.g., 3-20 glucose monomers), which may be selected to afford some tailoring of the surfactancy properties following functionalization with a quaternary ammonium halohydrin. Additional tailoring of the surfactancy properties may be realized throughAtty. Docket No.: 075716-000166selection of the structure of the quaternary ammonium halohydrin (A and R1, R2, and R3) and its quaternary ammonium group.

[0020] Maltodextrins have 3 to about 20 monosaccharide units (monomers) that are covalently linked by a(l,4) glycosidic bonds. Formula 4 below shows the generic structure of a dextrin parent compound having only a(l, 4) glycosic bonds between adjacent glucose monomer units, wherein variable 'a' is a positive integer ranging between 1 and about 18, thereby providing a dextrin containing 3 to about 20 glucose monomer units.Formula 4Other dextrin parent compounds may contain only a(l,6) glycosidic bonds, and such dextrin parent compounds may also form cationic saccharide polymers suitable for use in the disclosure herein. Any hydroxyl group of the dextrin parent compound may undergo functionalization with the quaternary ammonium halohydrin. The cationic functional groups introduced by the quaternary ammonium halohydrin may be distributed randomly throughout the dextrin compound at loading levels described further herein.

[0021] In addition to the number of glucose monomer units that are present, maltodextrins may be characterized in terms of their dextrose equivalent (DE) value. Dextrose equivalent is a measure of the amount of reducing sugars that are present in a saccharide oligomer, particularly a dextrin, expressed as a percentage relative to dextrose. Starch, which is functionally non-reducing, has a defined dextrose equivalent of 0, whereas dextrose itself has a defined dextrose equivalent of 100. Higher dextrose equivalent values are characteristic of a lower number of covalently linked glucose monomers (shorter polymer backbone length). Maltodextrins suitableAtty. Docket No.: 075716-000166for use in the present disclosure may exhibit dextrose equivalent values ranging from about 1 to about 30, or about 3 to about 30, or about 13 to about 25, or about 13 to about 20.

[0022] Maltodextrins suitable for use in the present disclosure may be obtained from hydrolysis or pyrolysis of starch, specifically the amylose component of starch, according to some embodiments. A maltodextrin having Formula 4, for example, may be formed by hydrolysis or pyrolysis of amylose. Alternative dextrins suitable for use in the disclosure herein may be obtained from hydrolysis or pyrolysis of the amylopectin component of starch, in which case the dextrin may contain a(l,6) glycosidic bonds.

[0023] Polysaccharides and dextrin compounds may undergo a reaction with the quaternary ammonium halohydrin under similar conditions to produce the cationic saccharide polymers described herein. The reaction between the saccharide polymer and the quaternary ammonium halohydrin may take place at a temperature suitable for functionalization to take place. In non-limiting examples, the reaction may take place below room temperature, at or near room temperature, or at an elevated temperature. For example, the reaction may take place at a temperature ranging from about 10°C to about 70°C for a period of time ranging from about 1 hour to about 96 hours or about 24 hours to about 96 hours. A higher degree of functionalization may be realized at lower reaction temperatures, such as about 25°C or below. The reaction may be carried out in water or a similar aqueous medium and in the presence of a hydroxide base, such as sodium hydroxide, potassium hydroxide, or any combination thereof.

[0024] Any of the saccharide monomers in the parent saccharide polymer may undergo functionalization with the quaternary ammonium halohydrin. Zero, one, or more than one hydroxyl groups in the saccharide monomers may undergo functionalization.

[0025] The loading of quaternary ammonium groups within the cationic saccharide polymers may range from about 0.5 mol% to about 40 mol%, or about 1 mol% to about 25 mol° / o, or about 5 mol% to about 10 mol%, or about 10 mol% to about 20 mol%, or about 15 mol% to about 30 mol%, based on total moles of quaternary ammonium groups relative to saccharide monomers in the saccharide polymer. Where present, theAtty. Docket No.: 075716-000166quaternary ammonium groups may be arranged randomly within the saccharide monomers, and may be located upon any hydroxyl group within the saccharide monomers.

[0026] The cationic saccharide polymers described hereinabove may be provided, sourced, mixed, stored, or used in a solid form or in a liquid form. Liquid forms may include in a suitable fluid phase. As used herein, the terms "fluid" and "fluid phase" refer to both liquids and gels, including both solutions and suspensions of the cationic saccharide polymer, unless otherwise indicated. The fluid may comprise an aqueous fluid. Suitable aqueous fluids for use herein may include, for example, fresh water, acidified water, seawater, brine ( / .e., a saturated salt solution), or an aqueous salt solution ( / .e., a nonsaturated salt solution). Water-miscible organic co-solvents such as ethanol or ethylene glycol, for example, may be optionally present in combination with an aqueous fluid in the compositions of the present disclosure.

[0027] In some embodiments, the cationic saccharide polymers of the present disclosure may be formulated as a subterranean treatment fluid. Treatment fluids may be used in a variety of subterranean treatment operations to facilitate or promote a particular action within the subterranean formation. As used herein, the terms "treat," "treatment," "treating," and grammatical equivalents thereof refer to any subterranean operation that uses a fluid in conjunction with achieving a desired function and / or for a desired purpose. Unless otherwise specified, use of these terms does not imply any particular action by the treatment fluid or a component thereof. Illustrative treatment operations that may be facilitated through use of the cationic saccharide polymers of the present disclosure include, without limitation, drilling operations, stimulation operations, production operations, remediation operations, sand control operations, and the like, which may include, for example, fracturing operations, gravel packing operations, acidizing operations, descaling operations, consolidation operations, workover operations, cleanup operations, and the like. Alternately, the cationic saccharide polymers of the present disclosure may be used in conjunction with excavation or mining.

[0028] When included in a treatment fluid, the cationic saccharide polymers may be present in an amount ranging from about 0.1 gallons perAtty. Docket No.: 075716-000166thousand gallons (gpt) to about 10 gpt, or about 0.5 gpt to about 5 gpt, or about 1 gpt to about 3 gpt. These concentrations correspond to volume / volume percentages ranging from about 0.01% to about 1%, or about 0.05% to about 0.5%, or 0.1% to about 0.3%. Even lower concentrations in the range of about 0.0005 wt% to about 0.01 wt% (5-100 ppm) may also be suitably used.

[0029] Treatment fluids containing the cationic saccharide polymers may optionally further comprise any number of additives, particularly those that are commonly used in the oilfield services industry. Illustrative additives that may be present in combination with the cationic saccharide polymers of the present disclosure include, but are not limited to, surfactants, viscosifiers, gelling agents, gel stabilizers, anti-oxidants, polymer degradation prevention additives, relative permeability modifiers, scale inhibitors, corrosion inhibitors, chelating agents, foaming agents, defoaming agents, antifoaming agents, emulsifying agents, de-emulsifying agents, iron control agents, proppants or other particulates, particulate diverters, salts, acids, fluid loss control additives, gas, catalysts, other clay control agents, dispersants, flocculants, scavengers, lubricants, breakers, friction reducers, bridging agents, weighting agents, solubilizers, pH control agents (e.g., buffers), hydrate inhibitors, consolidating agents, bactericides, catalysts, the like, and any combination thereof. Suitable examples of these additives will be familiar to one having ordinary skill in the art.

[0030] In subterranean treatment operations or in other applications, the cationic saccharide polymers of the present disclosure may perform various functions. Example functions include corrosion inhibition and removal of one or more pollutants from an aqueous fluid, as described in greater detail hereinafter.

[0031] In some examples, the cationic saccharide polymers may be utilized for preventing or limiting corrosion. These two effects are interchangeably referenced as "corrosion inhibition" herein. Thus, corrosion inhibition may prevent corrosion from occurring in the first place or decrease the rate at which corrosion occurs in a corrosive environment.

[0032] Corrosion refers to the degradation of a metal surface as a consequence of contact with an acid, an acid-generating substance, or a similarAtty. Docket No.: 075716-000166type of corrosive environment. Corrosion may occur as uniform thinning ( / '.e., general corrosion), localized pitting, or any combination thereof. Examples of common types of corrosion include, but are not limited to, rusting of a metal, at least partial metal dissolution, and patina development on a metal surface. Any of these corrosive effects may be mitigated using the cationic saccharide polymers disclosed herein.

[0033] In the oilfield and pipelines, acid gases, such as carbon dioxide and hydrogen sulfide, may be particularly problematic in promoting corrosion. High-concentration salt solutions, such as aqueous brines, may lead to or exacerbate corrosion as well.

[0034] Methods for inhibiting corrosion may comprise: providing a composition comprising a cationic saccharide polymer of the present disclosure, contacting a metal surface with the composition, exposing the metal surface to corrosive conditions, and allowing the composition to decrease an extent of corrosion of the metal surface. Inhibition of corrosion may be evaluated relative to the extent that corrosion occurs upon the metal surface without the cationic saccharide polymer or a similar corrosion inhibitor being present.

[0035] As used herein, the term "inhibit" and its derivatives refer to a lessening of the tendency for a phenomenon (e.g., corrosion) to occur and / or the degree to which that phenomenon occurs. The term "inhibit" does not imply any particular degree or amount of inhibition.

[0036] The cationic saccharide polymer may promote corrosion inhibition by contacting the metal surface prior with the composition prior to the metal surface being exposed to the corrosive conditions. In this instance, the corrosion inhibition may be proactive and protective in nature. Without being bound by theory or mechanism, the cationic saccharide polymer may form at least a partial coating upon the metal surface to exert a corrosioninhibiting effect. Alternately or additionally, the cationic saccharide polymer may promote corrosion inhibition by contacting the metal surface with the composition while the metal surface is being exposed to the corrosive conditions. In this instance, the corrosion inhibition may be reactive in nature, once corrosive conditions have been identified. For example, if the metal surface has not been previously contacted with the cationic saccharideAtty. Docket No.: 075716-000166polymer, the cationic saccharide polymer may be introduced to an aqueous fluid in which corrosive conditions have been identified in order to limit the amount of corrosion taking place.

[0037] In some examples, the cationic saccharide polymer may be present during an acidizing operation conducted in a subterranean formation. In some or other examples, the cationic saccharide polymer may be deployed in a subterranean formation to mitigate the effects of an acid gas, such as carbon dioxide and / or hydrogen sulfide, during hydrocarbon production.

[0038] The cationic saccharide polymer may be present in the composition in an amount effective to inhibit corrosion to a desired degree. In non-limiting examples, the concentration of the cationic saccharide polymer may range from 0.0001 wt% to about 0.1 wt% (1 ppm to 1000 ppm), or about 0.0001 wt% to about 0.01 wt% (1 ppm to 100 ppm), or about 0.01 wt% to about 0.05 wt% (100 ppm to 500 ppm), or about 0.05 wt% to about 0.1 wt% (500 ppm to 1000 ppm) in compositions suitable for inhibiting corrosion.

[0039] In addition to the cationic saccharide polymer, other corrosion inhibitors may also be present in the compositions. Other types of corrosion inhibitors that may be present include, but are not limited to, phosphonates and aldehyde reaction products.

[0040] Suitable metal surfaces to be protected by compositions containing the cationic saccharide polymer may include any metal surface that is susceptible to corrosion. Examples include, but are not limited to, ferrous metals, low alloy metals, stainless steel, copper alloys, brass, nickel alloys, and duplex stainless steel alloys. Example types of metal surfaces that may be protected include, but are not limited to, pipeline interiors, downhole tools, reactor surfaces, and the like.

[0041] Particularly suitable alkyl groups for addressing corrosion may include C10-C18 alkyl groups, or C10-C14 alkyl groups, or C14-C18 alkyl groups.

[0042] In addition to promoting corrosion inhibition, the cationic saccharide polymers of the present disclosure may also be utilized in conjunction with at least partial removal of organic pollutants from aqueous fluids. In particular examples, compositions containing the cationic saccharide polymers of the present disclosure may be utilized to promote at least partialAtty. Docket No.: 075716-000166removal of perfluorinated alkyl substances (PFAS), also referred to as polyfluorinated alkyl substances, from aqueous fluid. PFAS are increasingly being referred to as "forever chemicals" due to their very slow environmental breakdown. Accordingly, effective methods for at least partially removing PFAS from aqueous fluids may be highly desirable.

[0043] Methods for processing aqueous fluids to remove organic contaminants therefrom may comprise: providing a composition comprising a cationic saccharide polymer of the present disclosure, contacting an aqueous fluid containing one or more organic pollutants with the composition, and obtaining an at least partially remediated aqueous fluid after contacting the aqueous fluid with the composition, wherein the at least partially remediated aqueous fluid has a lower concentration of at least one of the one or more organic pollutants.

[0044] In non-limiting examples, contacting between the aqueous fluid and the composition containing the cationic saccharide polymer may take place in a manner to promote a reduction in concentration of at least one of the one or more contaminants. In some examples, the separation of one or more organic contaminants may take place by foaming the aqueous fluid to produce a foam, and separating the foam from the aqueous fluid. The cationic saccharide polymer may promote entrainment of one or more organic contaminants within the foam, and removal of the foam from the aqueous fluid may carry the one or more organic contaminants away from the remaining aqueous fluid, thereby decreasing the concentration of the organic contaminant(s) therein. Without being bound by theory or mechanism, the cationic saccharide polymer may not only promote foaming of the aqueous fluid but also facilitate association of a hydrophobic portion of the one or more contaminants with a bubble structure of the foam. The length of the hydrophobic portion of the one or more organic contaminants may determine how readily the one or more organic contaminants associate with the bubble structure. The structure of the cationic saccharide polymer may further tailor the extent to which the one or more organic contaminants associate with the foam.

[0045] In non-limiting examples, a foam may be produced by introducing a composition containing a cationic saccharide polymer of theAtty. Docket No.: 075716-000166present disclosure to an aqueous fluid, and then bubbling a gas (e.g., air, carbon dioxide, nitrogen, natural gas, or the like) through a column of the aqueous fluid to create the foam. As the foam overflows the top of the column, organic pollutant(s) entrained within the foam are removed from the aqueous fluid.

[0046] The cationic saccharide polymer may be present in the composition in an amount effective to promote foaming and entrainment of one or more organic contaminants within the foam. In non-limiting examples, the concentration of the cationic saccharide polymer may range from about 0.0001 wt% to about 0.1 wt% (1 ppm to 1000 ppm), or about 0.0001 wt% to about 0.01 wt% (1 ppm to 100 ppm), or about 0.001 wt% to about 0.01 wt% (10-100 ppm), or about 0.01 wt% to about 0.05 wt% (100 ppm to 500 ppm), or about 0.05 wt% to about 0.1 wt% (500 ppm to 1000 ppm) in compositions suitable for promoting foaming and entrainment of organic pollutants.

[0047] In more particular examples, the one or more organic pollutants may comprise at least one PFAS. PFAS that may be at least partially removed from aqueous fluids using the cationic saccharide polymers disclosed herein may include, but are not limited to, C3-C12 PFAS, including carboxylic acid PFAS and sulfonic acid PFAS. Examples of PFAS that may be removed from an aqueous fluid according to the disclosure herein include, but are not limited to, PFBA (perfluorobutanoic acid), PFMPA (perfluoro-3-methoxypropanoic acid, 3:3 FTCA (3-perfluoropropylpropanoic acid / 3:3 fluorotelomer carboxylic acid), PFPeA (perfluoropentanoic acid), PFBS (perfluorobutanesulfonic acid), PFHxA (perfluorohexanoic acid), PFHpA (perfluoroheptanoic acid), 5:3 FTCA (3-perfluoropentylpropanoic acid / 5:3 fluorotelomer carboxylic acid), PFHxS (perfluorohexanesulfonic acid), 6:2 FTSA (2-perfluorohexylethanesulfonic acid / 6:2 fluorotelomer sulfonic acid), PFOA (perfluorooctanoic acid), PFHpS (perfluoroheptanesulfonic acid), PFNA (perfluorononanoic acid), PFOS (perfluorooctanesulfonic acid), 8:2 FTSA (2-perfluorooctylethanesulfonic acid / 8:2 fluorotelomer sulfonic acid), PFDA (perfluorodecanoic acid), 4:2 FTSA (2-perfluorobutylethanesulfonic acid / 4:2 fluorotelomer sulfonic acid), PFPeS (perfluoropentanesulfonic acid), and N-EtFOSAA (N-ethyl perfluorooctane sulfonamidoacetic acid).Atty. Docket No.: 075716-000166

[0048] Particularly suitable alkyl groups for promoting PFAS removal may include C10-C18 alkyl groups, or C10-C14 alkyl groups, or C14-C18 alkyl groups.

[0049] In non-limiting examples, the cationic saccharide polymers of the present disclosure may remove at least about 70% of the PFASs or other organic pollutants from an aqueous fluid, or at least about 80% of the PFASs or other organic pollutants from an aqueous fluid, or at least about 90% of the PFASs or other organic pollutants from an aqueous fluid, or at least about 95% of the PFASs or other organic pollutants from an aqueous fluid, or at least about 98% of the PFASs or other organic pollutants from an aqueous fluid, each as measured relative to total mass of the PFASs or other organic pollutants.

[0050] Embodiments disclosed herein include:

[0051] Embodiment 1. A method comprising:providing a composition comprising a cationic saccharide polymer, the cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer;contacting a metal surface with the composition; exposing the metal surface to corrosive conditions; and allowing the composition to decrease an extent of corrosion of the metal surface.

[0052] Embodiment 2. The method of Embodiment 1, wherein the metal surface is contacted with the composition prior to being exposed to the corrosive conditions.

[0053] Embodiment 3. The method of Embodiment 1 or Embodiment 2, wherein the metal surface is contacted with the composition while being exposed to the corrosive conditions.

[0054] Embodiment 4. The method of any one of Embodiments 1-3, wherein the parent saccharide polymer comprises a dextran or a dextrin compound.

[0055] Embodiment 5. The method of any one of Embodiments 1-4, wherein the parent saccharide polymer comprises a maltodextrin.

[0056] Embodiment 6. The method of Embodiment 5, wherein the maltodextrin has a dextrose equivalent of about 10 or greater.Atty. Docket No.: 075716-000166

[0057] Embodiment 7. The method of any one of Embodiments 1-6, wherein the quaternary ammonium halohydrin has a structure represented by OH R1whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

[0058] Embodiment 8. The method of Embodiment 7, wherein at least one of R1, R2, and R3is a C1-C18 alkyl group.

[0059] Embodiment 9. The method of Embodiment 7 or Embodiment 8, wherein A is -CH2-.

[0060] Embodiment 10. The method of any one of Embodiments 7-9, wherein X is chloride.

[0061] Embodiment 11. A method comprising:providing a composition comprising a cationic saccharide polymer, the cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer;contacting an aqueous fluid containing one or more organic pollutants with the composition; andobtaining an at least partially remediated aqueous fluid after contacting the aqueous fluid with the composition, the at least partially remediated aqueous fluid having a lower concentration of at least one of the one or more organic pollutants.

[0062] Embodiment 12. The method of Embodiment 11, wherein the parent saccharide polymer comprises a dextran or a dextrin compound.

[0063] Embodiment 13. The method of Embodiment 11 or Embodiment 12, wherein the parent saccharide polymer comprises a maltodextrin.Atty. Docket No.: 075716-000166

[0064] Embodiment 14. The method of Embodiment 13, wherein the maltodextrin has a dextrose equivalent of about 10 or greater.

[0065] Embodiment 15. The method of any one of Embodiments 11-14, wherein the quaternary ammonium halohydrin has a structure represented byOH R1whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

[0066] Embodiment 16. The method of Embodiment 15, wherein at least one of R1, R2, and R3is a C1-C18 alkyl group.

[0067] Embodiment 17. The method of Embodiment 15 or Embodiment 16, wherein A is -CH2-.

[0068] Embodiment 18. The method of any one of Embodiments 15-17, wherein X is chloride.

[0069] Embodiment 19. The method of any one of Embodiments 11-18, wherein contacting the aqueous fluid with the composition comprises:foaming the aqueous fluid to produce a foam; and separating the foam from the aqueous fluid;wherein at least one of the one or more organic pollutants is entrained within the foam.

[0070] Embodiment 20. The method of any one of Embodiments 11-19, wherein the one or more organic pollutants comprises one or more perfluoroalkyl substances (PFAS).

[0071] Embodiment 21. A composition comprising:a cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin or epoxide and a maltodextrin;wherein the quaternary ammonium halohydrin has a structure represented byAtty. Docket No.: 075716-000166OH R1UR2^R3whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

[0072] Embodiment 22. The composition of Embodiment 21, wherein at least one of R1, R2, and R3is a C1-C18 alkyl group.

[0073] Embodiment 23. The composition of Embodiment 21 or Embodiment 22, wherein A is -CH?-.

[0074] Embodiment 24. The composition of any one of Embodiments 21-23, wherein X is Cl.

[0075] Embodiment 25. The composition of any one of Embodiments 21-24, further comprising:an aqueous carrier fluid.

[0076] To facilitate a better understanding of the disclosure herein, the following examples of various representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the invention.EXAMPLES

[0077] Materials. Maltodextrins having a dextrose equivalent of 23.0-27.0 (MD1) or having a dextrose equivalent of 13.0-17.0 (MD2) were used as received. Dextran having a molecular weight of 3 million daltons was used as received. Quaternary ammonium halohydrins reacted with the maltodextrins or dextran included 3-chloro-2-hydroxypropyl-lauryl-dimethylammonium chloride (HH1) and 3-chloro-2-hydroxypropyl-trimethylammonium chloride (HH2). Particular reaction products are indicated in the data tables below.

[0078] General Procedure for Making Cationic Saccharide Polymers. The selected maltodextrin or dextran and quaternary ammonium halohydrin were reacted by dissolving the maltodextrin or dextran in water and adding the quaternary ammonium halohydrin and a hydroxide base, followedAtty. Docket No.: 075716-000166by stirring at room temperature. Progress of the reaction was evaluated by monitoring the disappearance of the quaternary ammonium halohydrin by HPLC. For MDl, the quaternary ammonium halohydrin was present at a molar ratio of 1 :5 with respect to saccharide monomers in the maltodextrin. For MD2 and dextran, the quaternary ammonium halohydrin was present at a molar ratio of 1:10 with respect to saccharide monomers in the maltodextrin.

[0079] Corrosion Inhibition Procedure and Testing Results. Flat 1018 carbon steel coupons were obtained and weighed. After determining the initial weight, the coupons were contacted with synthetic seawater brine (10370 ppm Na+, 365 ppm K+, 622 ppm Mg2+, 316 ppm Ca2+, 0.1 ppm Sr2+, 17590 ppm Cl’, 2765 ppm SC2-, 146 ppm HCO3 ). that had been purged with carbon dioxide for at least one hour and until the pH reached 4.5-5.5. For initial treatment, an empty bottle was purged with carbon dioxide and then the cationic saccharide polymer, the synthetic brine, and kerosene were added under an atmosphere of carbon dioxide. The concentration of the cationic saccharide polymer was fixed at either 10 ppm or 100 ppm. The coupon was added to the bottle, which was then sealed and agitated for 1 hour on a rotating wheel apparatus. After 1 hour, the coupon was contacted for an additional hour at room temperature with fresh kerosene and synthetic seawater brine lacking the cationic saccharide polymer. Finally, the coupon was contacted with another portion of kerosene and fresh synthetic seawater brine and treated at 176°F for 24 hours.

[0080] Corrosion inhibition testing data is summarized in Table 1. Testing values in Table 1 are averaged values for 3 replicates at each concentration and testing time. Corrosion inhibition is measured as (1- corrosion losssampie / corrosion losscontrol x 100%.Table 1Avg. Mils Corrosion Saccharide Cone, Per Year Inhibition Sample HalohydrinPolymer (ppm) Corrosion Relative to #Loss Blank (%) Blank — — 0 18.50 — 1 MDl HH1 10 10.56 42.9 2 MDl HH1 100 10.05 45.7Atty. Docket No.: 075716-000166Avg. Mils Corrosion Saccharide Cone. Per Year Inhibition Sample HalohydrinPolymer (PPm) Corrosion Relative to #Loss Blank (%) 3 DI HH1 10 6.85 63.0 4 DI HH1 100 6.74 63.6 5 D2 HH1 10 10.18 45.0 6 D2 HH1 100 3.65 80.3

[0081] PFAS Removal Procedure and Testing Results. Removal of PFAS from water was performed by foam fractionation. After dissolving the cationic saccharide polymer in a PFAS-containing aqueous fluid, the aqueous fluid was placed in a column, and air or nitrogen gas was bubbled through the column to create a foam. PFAS molecules absorbed upon the foam bubbles and were removed as the foam overflowed the top of the column.

[0082] PFAS removal data is summarized in Tables 2 and 3. In Tables 2 and 3, the abbreviations correspond to the following chemical names: PFBA = perfluorobutanoic acid; PFMPA = perfluoro-3-methoxypropanoic acid; 3:3 FTCA = 3-perfluoropropylpropanoic acid (3:3 fluorotelomer carboxylic acid); PFPeA = perfluoropentanoic acid; PFBS = perfluorobutanesulfonic acid; PFHxA = perfluorohexanoic acid; PFHpA = perfluoroheptanoic acid; 5:3 FTCA = 3- perfluoropentylpropanoic acid (5:3 fluorotelomer carboxylic acid); PFHxS = perfluorohexanesulfonic acid; 6:2 FTSA = 2-perfluorohexylethanesulfonic acid (6:2 fluorotelomer sulfonic acid); PFOA = perfluorooctanoic acid; PFHpS = perfluoroheptanesulfonic acid; PFNA = perfluorononanoic acid; PFOS = perfluorooctanesulfonic acid; 8:2 FTSA = 2-perfluorooctylethanesulfonic acid (8:2 fluorotelomer sulfonic acid); PFDA = perfluorodecanoic acid; 4:2 FTSA = 2-perfluorobutylethanesulfonic acid; PFPeS = perfluoropentanesulfonic acid; and N-EtFOSAA = N-ethyl perfluorooctane sulfonamidoacetic acid.

[0083] Table 2 shows the PFAS removal data for several cationic saccharide polymers in comparison to cetyltrimethylammonium bromide (CTAB).Atty. Docket No.: 075716-000166Table 2PFAS Removal (%)TotalPFAS Carbons CTAB MD1 / HH1 MD2 / HH1 MD2 / HH2 in PFASPFBA C4 15 33 3 6 PFMPA C4 23 31 25 183:3 C6 6 22 45 24 FTCA PFPeA C5 46 62 65 39 PFBS C4 98 99.8 99.3 72 PFHxA C6 99.1 98 98 95 PFHpA C7 >99.0 >98 >98.3 >98.8 5:3 C8 >98 >98.4 >98.2 >98.0 FTCA PFHxS C6 >98 N / A >93 >96 6:2 C8 >99 >92 >94 >96 FTSA PFOA C8 N / A >98.6 >98.5 >99.0 PFHpS C7 >93 N / A N / A N / A PFNA C9 >97 N / A N / A >90 PFOS C8 NA 94 >95 >97 8:2 CIO >83 N / A N / A N / A FTSA PFDA CIO N / A >96 >93 >95

[0084] Table 3 shows the PFAS removal data for several PFAS-containing aqueous fluids treated with cationic maltodextrins prepared from MD1 and HH1.Atty. Docket No.: 075716-000166Table 3PFAS Removal (%)PFAS Total Aqueous Aqueous Aqueous Carbons Fluid A Fluid B Fluid Cin PFASPFBA C4 33 79 >98.8PFMPA C4 31 N / A N / A3:3 C6 22 >59 N / AFTCA PFPeA C5 62 >99.9 99.2PFBS C4 99.8 >98.6 N / A4:2 C6 N / A >38 N / AFTSA PFHxA C6 98 >99.9 99.0PFPeS C5 N / A >98.5 N / APFHpA C7 >98.2 >99.5 >965:3 C8 >98.4 N / A >64FTCA PFHxS C6 N / A >99.6 N / A6:2 C8 >92 N / A 96FTSA PFOA C8 >98.6 >99.4 >86PFHpS C7 N / A >67 N / APFNA C9 N / A >99.3 >72PFOS C8 94 99.5 >98.58:2 CIO N / A N / A N / AFTSA PFDA CIO >96 >67 >75N- C12 N / A N / A N / AEtFOSAA

[0085] All documents described herein are incorporated by reference herein for purposes of all jurisdictions where such practice is allowed, including any priority documents and / or testing procedures to the extent they are notAtty. Docket No.: 075716-000166inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited thereby. For example, the compositions described herein may be free of any component, or composition not expressly recited or disclosed herein. Any method may lack any step not recited or disclosed herein. Likewise, the term "comprising" is considered synonymous with the term "including." Whenever a method, composition, element, or group of elements is preceded with the transitional phrase "comprising," it is understood that we also contemplate the same composition or group of elements with transitional phrases "consisting essentially of," "consisting of," "selected from the group consisting of," or "is" preceding the recitation of the composition, element, or elements and vice versa.

[0086] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated 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 may vary depending upon the desired properties sought to be obtained by the embodiments of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0087] Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, "from about a to about b," or, equivalently, "from approximately a to b," or, equivalently, "from approximately a-b") disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, theAtty. Docket No.: 075716-000166indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

[0088] One or more illustrative embodiments are presented herein. Not all features of a physical implementation are described or shown in this application for the sake of clarity. It is understood that in the development of a physical embodiment of the present disclosure, numerous implementationspecific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government-related and other constraints, which vary by implementation and from time to time. While a developer's efforts might be time-consuming, such efforts would be, nevertheless, a routine undertaking for one of ordinary skill in the art and having benefit of this disclosure.

[0089] Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to one having ordinary skill in the art and having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present disclosure. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and / or any optional element disclosed herein.

Claims

Atty. Docket No.: 075716-000166CLAIMSWhat is claimed is the following:

1. A method comprising:providing a composition comprising a cationic saccharide polymer, the cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer;contacting a metal surface with the composition;exposing the metal surface to corrosive conditions; and allowing the composition to decrease an extent of corrosion of the metal surface.

2. The method of claim 1, wherein the metal surface is contacted with the composition prior to being exposed to the corrosive conditions.

3. The method of claim 1, wherein the metal surface is contacted with the composition while being exposed to the corrosive conditions.

4. The method of any one of claims 1-3, wherein the parent saccharide polymer comprises a dextran or a dextrin compound.

5. The method of any one of claims 1-3, wherein the parent saccharide polymer comprises a maltodextrin.

6. The method of claim 5, wherein the maltodextrin has a dextrose equivalent of about 10 or greater.

7. The method of any one of claims 1-3, wherein the quaternary ammonium halohydrin has a structure represented byOH R1whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

8. The method of claim 7, wherein at least one of R1, R2, and R3is a Cl- C18 alkyl group.Atty. Docket No.: 075716-0001669. The method of claim 7, wherein A is -CH2-.

10. The method of claim 7, wherein X is chloride.

11. A method comprising:providing a composition comprising a cationic saccharide polymer, the cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin or epoxide and a parent saccharide polymer;contacting an aqueous fluid containing one or more organic pollutants with the composition; andobtaining an at least partially remediated aqueous fluid after contacting the aqueous fluid with the composition, the at least partially remediated aqueous fluid having a lower concentration of at least one of the one or more organic pollutants.

12. The method of claim 11, wherein the parent saccharide polymer comprises a dextran or a dextrin compound.

13. The method of claim 11, wherein the parent saccharide polymer comprises a maltodextrin.

14. The method of claim 13, wherein the maltodextrin has a dextrose equivalent of about 10 or greater.

15. The method of any one of claims 11-14, wherein the quaternary ammonium halohydrin has a structure represented byOH R1whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

16. The method of claim 15, wherein at least one of R1, R2, and R3is a Cl- C18 alkyl group.

17. The method of claim 15, wherein A is -CH2-.

18. The method of claim 15, wherein X is chloride.Atty. Docket No.: 075716-00016619. The method of any one of claims 11-14, wherein contacting the aqueous fluid with the composition comprises:foaming the aqueous fluid to produce a foam; and separating the foam from the aqueous fluid;wherein at least one of the one or more organic pollutants is entrained within the foam.

20. The method of any one of claims 11-14, wherein the one or more organic pollutants comprises one or more perfluoroalkyl substances (PFAS).

21. A composition comprising:a cationic saccharide polymer comprising a reaction product of a quaternary ammonium halohydrin and a maltodextrin;wherein the quaternary ammonium halohydrin has a structure represented byOH R1whereinX is a halide;A is a C1-C10 alkylene group; andR1, R2, and R3are independently C1-C30 alkyl groups.

22. The composition of claim 21, wherein at least one of R1, R2, and R3is a C1-C18 alkyl group.

23. The composition of claim 21 or claim 22, wherein A is -CH2-.

24. The composition of claim 21 or claim 22, wherein X is Cl.

25. The composition of claim 21 or claim 22, further comprising:an aqueous carrier fluid.

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