Defoaming agent and composition containing same

Abstract

The present disclosure relates to a method of treating an aqueous foamable medium, such as a process stream of a pulping and paper mill, comprising contacting the aqueous process stream with a defoaming agent comprising: a) at least one C12 to C40 Guerbet alcohol; and / or b) at least one polyol ester.

Description

Technical Field

[0001] This disclosure relates to defoamers, particularly suitable for pulp and paper mill applications, based on bio-renewable materials. More specifically, this disclosure relates to the use of at least one selected from polyol esters and C in pulp and paper mill applications. 18 -C 36 Gerbert alcohol compounds are used as defoamers. Background Technology

[0002] In pulp and paper mills, the four main factors generally considered to lead to foam formation are: the presence of an air source; the use of a low-viscosity liquid medium, more specifically an aqueous medium; the mechanical energy applied to the liquid medium in the presence of the air source; and the presence of a compound in the liquid medium that contributes to foam formation and its stability—a surfactant.

[0003] It is understood that pulp and paper mills contain numerous devices for transferring mechanical energy and for agitating, applying shear, or creating turbulence in liquid media. Furthermore, the process stream of the liquid media may contain many compounds with surface-active properties inherent to the pulp source. This is particularly true for alkaline black liquor, for example, where the foam generated during pulp washing is difficult to regulate: alkaline black liquor contains lignin as well as fatty acids and resin acids in saponified or salted forms, which can act as natural foam stabilizers. Exogenous or process-specific surface-active chemicals may also be added to a given liquid process stream, which can stabilize or disperse surface foam: particulate matter, such as fillers and fine powders, can be mentioned in this regard.

[0004] Foam control is necessary in pulp and paper mills for purposes including: minimizing the loss of process chemicals; reducing unwanted foam; enhancing pad dewatering; and increasing the processing capacity of constituent units. Control can be achieved through mechanical defoaming, but this requires capital expenditure on equipment and ongoing investment in its maintenance. Alternatively, foam control can be achieved through chemical defoaming, which has the advantage of not requiring major modifications to the paper mill's processes and related equipment.

[0005] Chemical defoamers can function through a variety of mechanisms. For example, when a treatment composition contains water-insoluble, nonpolar solvents, these solvents can spread on the surface of an aqueous liquid, forming new surfaces that cause surface foam to break down. Reactive defoamers in a treatment composition can react with or couple with foam-stabilizing compounds, producing unstable foam products. Alternatively, defoamers can reduce foam stability by increasing surface tension, decreasing surface viscosity, or reducing hydrogen bonding. In some cases, defoamers may promote foam breakage by creating localized low surface tension points.

[0006] Although many chemical defoamers are known, the use of silicone-based oil-in-water emulsions is very common. These emulsions typically consist of four components: i) water; ii) liquid polysiloxanes, with polydimethylsiloxane, polymethylphenylsiloxane, and polymethylvinylsiloxane being important examples; iii) hydrophobic silica particles; and iv) auxiliary components such as dispersants and surfactants. While they are generally effective as defoamers, it is difficult to manufacture such oil-in-water emulsions with operable stability: the manufacturing process is time-consuming and requires heating, primarily because the viscosity of the defoamer components needs to be reduced before emulsion formation, and shear forces are required to homogenize the silica to the desired uniform particle size in the liquid polysiloxane.

[0007] If the emulsion lacks sufficient stability, phase separation may occur, which reduces defoaming effectiveness and may promote the formation of dirt and deposits. Due to the hydrophobicity of polysiloxanes, these polymers have a high affinity for any hydrophobic surface. Especially when the process stream to be treated is at a high (alkaline) pH or high temperature, the reactive functional groups of polysiloxanes may condense on hydrophobic surfaces: this condensation contributes to the formation of gels, which may accumulate in any part of the plant.

[0008] Besides the issue of deposition, another motivation for reducing the use of polysiloxanes in defoaming processes stems from the fact that these oils tend to have low surface tension, making them prone to leakage from pulp and paper mill equipment. Furthermore, from an environmental perspective, the synthesis of polysiloxanes requires significant energy consumption, which to some extent offsets the benefits of polysiloxanes' degradation in the environment through hydrolysis and cracking, and their non-petroleum-derived origin.

[0009] It may be beneficial to at least partially replace polysiloxanes in defoaming compositions, and this would be particularly desirable if such a substitution could utilize renewable raw materials. However, in turn, such a substitution should not impair the defoaming effect.

[0010] US 2006 / 0128884 A1 (Cheng et al.) discloses an oil-based composition for controlling foam, comprising: a) 6 to 93 wt% of at least one triglyceride oil or mixture of triglyceride oils; b) 12 to 93 wt% of an organosilicon; c) 0.2 to 12.0 wt% of a triglyceride-organosilicon stabilizer; d) 0.2 to 12.0 wt% of hydrophobic silica; e) 0 to 12.0 wt% of one or more surfactants and dispersants; and f) 0 to 10 wt% of one or more thickeners. The composition is characterized in that each triglyceride oil, organosilicon, and organosilicon-triglyceride stabilizer has a flash point of at least 60°C.

[0011] US 2006 / 0128816 A1 (Cheng et al.) discloses an oil-in-water emulsion for controlling foam, comprising: a) an oil blend comprising: at least one triglyceride oil and a silicone oil and / or a modified silicone product, wherein the at least one triglyceride oil is selected from soybean oil, corn oil, castor oil, and mixtures thereof, and the weight ratio of the silicone oil and / or the modified silicone product to the at least one triglyceride oil is from about 6:94 to about 90:10; b) a phospholipid-containing stabilizer contained in the oil blend; c) hydrophobic particles; and d) a nonionic surfactant and a dispersant. The composition is characterized in that the flash point of the oil blend, the stabilizer, and the surfactant and dispersant are all at least 60°C.

[0012] Triglycerides used as partial substitutes for polysiloxanes in these defoaming compositions can be supplied from renewable sources, particularly vegetable and animal oils. Triglycerides may also offer advantages such as low toxicity, low volatility, high flash point, and rapid biodegradability. However, the suitability of some triglycerides may be limited by their poor oxidative stability, poor hydrolytic stability, and high viscosity index.

[0013] Therefore, it is desirable to provide an antifoaming composition that allows for at least partial substitution of polysiloxanes and allows the use of alternative active compounds other than triglycerides, although said active compounds may also be derived from biorenewable sources. Furthermore, other desirable features and characteristics of this disclosure will become apparent from the following detailed description and the appended claims, in conjunction with the accompanying drawings and the background section. Summary of the Invention

[0014] According to a first aspect of this disclosure, a method for treating an aqueous foamable medium is provided, the method comprising contacting the aqueous foamable medium with an antifoaming agent comprising: a) at least one C 12 To C 40 a) Guerbert alcohol; and / or b) at least one polyol ester.

[0015] This disclosure also provides a method for treating an aqueous process stream in a pulp and paper mill, the method comprising contacting the aqueous process stream with a defoamer comprising: a) at least one C 12 To C 40 a) Guerbert alcohol; and / or b) at least one polyol ester.

[0016] In some embodiments, the contact time between the defoamer and the aqueous process stream is 1 to 60 minutes, for example, 1 to 30 minutes. In some embodiments that are not mutually exclusive with the above, the dosage of the defoamer in contact with the aqueous process stream is 0.1 to 1000 ppm by weight, for example, 0.5 to 500 ppm by weight, based on the total weight of the aqueous process stream.

[0017] According to a second aspect of this disclosure, an aqueous emulsion for treating foamable aqueous media is provided, the treated emulsion comprising water and, based on the weight of the emulsion: The first defoamer, comprising 1 to 20% by weight, consists of the following: a) At least one C 12 To C 40 Guerbert alcohol; and / or b) At least one polyol ester; c) at least one water-immiscible liquid polysiloxane, comprising 1 to 30% by weight; and 0 to 5% by weight of d) hydrophobic particles.

[0018] In one exemplary embodiment, the treated emulsion comprises water and, based on the weight of the emulsion: 1 to 15% by weight, for example, 1 to 10% by weight of a first defoamer, which consists of the following: a) At least one C 12 To C 40 Guerbert alcohol; and / or b) At least one polyol ester; 5 to 25% by weight, for example 10 to 25% by weight of c) at least one water-immiscible liquid polysiloxane; and, 1 to 5% by weight, for example 1 to 3% by weight of d) hydrophobic particles.

[0019] The aqueous emulsion is particularly suitable for treating aqueous process flows in pulp and paper mills.

[0020] The at least one C 12 To C 40 Guerbert alcohol is preferably represented by the following formula:

[0021] Where: R g and R h Independently for C1-C 20 Alkyl groups; and, R g and R h The sum of the number of carbon atoms is 12 to 40, for example, 18 to 40 or 18 to 36.

[0022] Exemplary C 12 To C 40 Guerbert alcohols (which may be used alone or in combination) include: 2-hexyl-1-decanol; 2-octyl-1-decanol; 2-octyl-1-dodecanol; 2-hexyl-1-dodecanol; 2-decyl-1-tetradecanol; 2-dodecyl-1-hexadecanol; 2-tetradecyl-1-octadecanol; and 2-hexadecyl-1-eicosyl alcohol.

[0023] When present in defoamers, the polyol ester may comprise or consist of at least one polyol having 2 to 6 hydroxyl groups per molecule and C5-C64. 30 A partial or complete ester composition of saturated or unsaturated straight-chain fatty acids. Examples of such esters (which may be used alone or in combination) include: neopentyl glycol dioleate; trimethylolpropane dioleate; trimethylolpropane trioleate; trimethylolpropane triisostearate; 2-ethyl-2-nonanoyloxymethyl-1,3-propanediol trinonanoate; and pentaerythritol tetraoleate. For example, references may be made to the use of trimethylolpropane trioleate (TMPTO), trimethylolpropane triisostearate, or combinations thereof.

[0024] Each polysiloxane present in portion c) of the aqueous emulsion, in some embodiments, can be characterized as having a viscosity of 100 to 100,000 mPa·s measured at 25°C. Independent of or in addition to this characterization, said or each polysiloxane in portion c) of the aqueous emulsion may have the following general formula (C1): (C1) Where: n is an integer from 20 to 1000; Each R 1 Independently selected from C1-C4 alkyl or C6-C 18 Aryl; and, Each R 2 Independently selected from H, C1-C4 alkyl or C6-C 18 Aryl.

[0025] In an exemplary implementation: each R 1 Independently selected from C1-C2 alkyl or C6 aryl; and each R 2 Independently selected from H, C1-C2 alkyl, or C6 aryl. And in the illustrative embodiments, each R... 1 Independently selected from methyl or phenyl; and each R 2 It is independently selected from H, methyl, or phenyl.

[0026] In some embodiments, portion c) of the aqueous emulsion may contain at least one polysiloxane selected from poly(phenylmethylsiloxane), polydimethylsiloxane, and polymethylhydrosiloxane.

[0027] The hydrophobic particles included as part d) of the composition are preferably characterized by a median particle size (Dv50) of 0.01 to 20 μm as measured by laser diffraction. Independent of or in addition to this particle size characterization, part d) of the aqueous emulsion may, in some embodiments, include or consist of hydrophobic silica particles. Attached Figure Description

[0028] Various other objects, advantages, and features of this disclosure will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and wherein: Figures 1a to 1c depict defoaming test results obtained using the first exemplary composition according to the present disclosure, conducted in a foam tank.

[0029] Figure 2 The defoaming test results obtained using the second and third exemplary compositions according to this disclosure are depicted in a foam tank.

[0030] Figure 3 The defoaming test results obtained using the third and fourth exemplary compositions according to this disclosure are depicted in a foam tank. Detailed Implementation

[0031] The following detailed description is exemplary only and is not intended to limit this disclosure or its application and use. Furthermore, it is not intended to be bound by the foregoing background information or any theories set forth in the following detailed description.

[0032] definition As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise.

[0033] The terms “comprising,” “comprises,” and “comprised of” as used herein are synonymous with “including,” “includes,” “containing,” or “contains,” and are inclusive or open-ended, not excluding additional, unlisted members, elements, or method steps. The phrase “consisting of” is closed-ended, excluding all additional elements. Furthermore, the phrase “substantially constitutes” excludes additional substantive elements but allows the inclusion of non-substantive elements that do not substantially alter the nature of the invention.

[0034] When quantities, concentrations, sizes, and other parameters are expressed as ranges, preferred ranges, upper limits, lower limits, or preferred upper and lower limits, it should be understood that any range obtained by combining any upper or preferred value with any lower or preferred value is also specifically disclosed, regardless of whether the obtained range is explicitly mentioned in the context.

[0035] Furthermore, according to the standard interpretation, a weight range expressed as "from 0 to x" specifically includes 0% by weight: the component defined by this range may be absent from the material, or may be present in the material in an amount of up to x% by weight.

[0036] As used herein, the terms “preferred,” “preferably,” “desirably,” and “particularly” are used to refer to embodiments of this disclosure that may provide particular benefits in certain circumstances. However, listing one or more preferred, preferred, desired, or particularly embodiments does not imply that other embodiments are not useful, nor is it intended to exclude such other embodiments from the scope of this disclosure.

[0037] As used herein, the terms “exemplary” and “illustrative” are intended to be used as examples, instances, or illustrations. Any aspect or design described herein as “exemplary” or “illustrative” is not necessarily to be construed as being superior or more advantageous than other aspects or designs. Rather, the use of the terms “exemplary” and “illustrative” is intended to present concepts in a concrete manner.

[0038] When used throughout this application, the word "may" is used in a permissive sense—meaning potential—rather than in a mandatory sense.

[0039] Unless otherwise stated, all percentages, ratios and proportions used in this article are by weight.

[0040] As used in this article, the room temperature was 23°C ± 2°C.

[0041] As used herein, the term "flash point" refers to the lowest temperature at which a liquid releases a sufficient concentration of vapor within a test vessel to form a flammable mixture with air near the liquid surface. It can be determined using appropriate current standard test methods, including: ASTM D-56, the standard test method for determining flash point using a Tiger closed-cup tester; and ASTM D93, the standard test method for determining flash point using a Pensky-Martins closed-cup tester.

[0042] Unless otherwise specified, the viscosity of the compositions described herein was measured using a Brookfield RVT model viscometer under standard conditions of 20°C and 50% relative humidity (RH). This viscometer was calibrated using oils of known viscosity, ranging from 10 cps to 50,000 cps. Calibration was performed using a set of RV rotors connected to the viscometer. Measurements of the compositions were performed using a No. 6 rotor at 20 revolutions per minute for 1 minute until the viscometer reading stabilized. The viscosity corresponding to the stable reading was then calculated using the calibration.

[0043] Unless otherwise stated, the term "particle size" refers to the largest axis of the particle. For approximately spherical particles, the largest axis is the diameter.

[0044] The term "median particle size (Dv50)" as used in this paper refers to the particle size corresponding to 50% of the sampled particle volume that is greater than the Dv50 value and 50% that is less than the Dv50 value. The particle size was determined using laser diffraction with a particle size analyzer (PSA).

[0045] The degree of esterification of the polyol esters described herein can be determined by a volumetric determination of acid value (AV), which indicates the mass (mg) of potassium hydroxide (KOH) required to neutralize the free acid present in 1g of the ester. Acid value can be determined according to DIN EN ISO 2114.

[0046] As used herein, the term "defoamer" includes materials that have one or more of the following functions: foam suppression, defoaming, or degassing. Foam suppression refers to inhibiting or preventing foam formation. Defoaming refers to reducing or removing existing foam. Degassing refers to trapping the escape of air. It should be noted that the effectiveness of the defoamer in this application is measured by its effectiveness in reducing, minimizing, or removing existing foam. Compounds that have been shown to provide good defoaming effects and compositions containing said compounds are also expected to exhibit foam suppression effects. However, this is not always the case.

[0047] As used herein, the term "aqueous emulsion for treatment" and the abbreviation "treatment emulsion" refer to compositions that actually come into contact with aqueous foamable media (e.g., aqueous process flows in pulp or paper mills). The pH, temperature, and contact time of the treatment emulsion with a given medium are valid variables for the results and can be monitored manually or automatically and adjusted according to efforts to optimize defoaming performance.

[0048] As used herein, the term "dispersion" refers to a composition comprising discrete particles distributed in a continuous liquid medium.

[0049] As used herein, the term "emulsion" refers to a mixture of two or more immiscible liquids held in a liquid suspension, which may be stabilized in the presence of an emulsifier or surfactant. More specifically, the term "aqueous emulsion" refers to a mixture of water or an aqueous solution with an immiscible liquid (e.g., liquid wax, oil, or resin) held in a liquid suspension. When the dispersed phase is the wax, oil, or resin and is in a discontinuous phase, while the dispersion medium is in a continuous phase, it is referred to herein as an oil-in-water emulsion. Conversely, when water or an aqueous solution is the dispersed phase and the oil or wax is the continuous phase, it is referred to as a water-in-oil emulsion. The aqueous emulsions of this disclosure are preferably formulated as oil-in-water emulsions.

[0050] The term "foamable medium" refers to a non-gaseous, non-vaporous fluid material capable of serving as a matrix film for bubbles. In some embodiments, the foamable medium of this disclosure is characterized in that the half-life of the foam formed is at least 10 seconds, for example, at least 20 seconds or at least 40 seconds: the foam half-life refers to the time required for half the initial volume of the foam generated in the foamable medium to return to the bulk liquid phase when placed in a graduated column kept at rest at room temperature and atmospheric pressure. While the defoamers and treatment emulsions of this disclosure are practical for treating aqueous process streams in industrial applications, more specifically in treating aqueous process streams in pulp and paper mills, their use is also contemplated for foamable pharmaceutical and cosmetic compositions, paints, coatings, and adhesives.

[0051] As used herein, the term "aqueous process flow" refers to a liquid flow containing water and to which the treatment emulsion of this disclosure is added. In the context of a pulp and paper mill, the term is intended to cover any flow associated with it, including side flows, recirculating flows, and effluents. In one embodiment, the process flow is an aqueous flow containing suspended particles: as those skilled in the art will understand, the concentration of suspended particles in an aqueous process flow in a pulp and paper mill may vary depending on the stage of processing from which they originate.

[0052] Exemplary aqueous process flows in pulp and paper mills include brown pulp stream, green liquor, white liquor, black liquor, and, for the sulfite process, red liquor or brown liquor. As used herein, the term "green liquor" refers to the liquid produced from the melt of the dissolving sulfate process recovery furnace: green liquor typically contains sodium carbonate (Na₂CO₃), sodium sulfide (Na₂S), and sodium hydroxide (NaOH) as major compounds. As used herein, the term "white liquor" refers to a liquid containing sodium sulfide and sodium hydroxide as major components. As used herein, the term "black liquor" refers to a liquid from the sulfite process, which primarily contains lignin degradation products and other dissolved wood components, as well as sodium sulfide derived from the pulping process. The liquid equivalent to black liquor in the sulfite process is often referred to as "brown liquor," but terms such as red liquor, concentrated liquor, or sulfite liquor may also be used in the art.

[0053] The term "contact time" refers to the period of time during which the processed emulsion comes into contact with the foaming medium. Contact time begins when at least a portion of the processed emulsion comes into contact with the foaming medium (e.g., an aqueous process flow). In some embodiments, the contact time may be determined by the flow rate of the aqueous process flow.

[0054] Water used herein as a (co)solvent or diluent means water with a low solids content as understood by one of ordinary skill in the art. For example, this water may be distilled water, demineralized water, deionized water, reverse osmosis water, boiler condensate, or ultrafiltration water. In some cases, tap water may also be acceptable.

[0055] As used in this article, "solvent" refers to a substance capable of dissolving another substance to form a homogeneous solution; during the dissolution process, neither the solvent nor the dissolved substance undergoes a chemical change. Solvents can be polar or nonpolar. The term "alcohol solvent" includes all water-soluble monohydric alcohols, dihydric alcohols, or polyhydric alcohols that are liquids at 25°C under normal pressure.

[0056] As used herein, the term "water-miscible liquid" refers to a liquid that is completely miscible with water at room temperature. In this regard, liquids that are soluble, readily soluble, or extremely soluble in water, thus requiring the dissolution of 1 g of the compound in ≤ 30 ml of water at room temperature, are particularly preferred.

[0057] As used herein, the term "water-immiscible liquid" refers to a liquid that forms a two-phase system with water. In this regard, liquids that are slightly soluble, very slightly soluble, or almost insoluble in water are particularly preferred, thus requiring the dissolution of 1 g of the compound in ≥ 100 ml of water at room temperature.

[0058] As used in this article, “polyol” refers to any compound containing two or more hydroxyl groups; therefore, the term is intended to cover diols, triols, and compounds containing four or more -OH groups.

[0059] The term "partially esterified" is used to refer to partially esterified polyols (polyhydroxy compounds) in which at least one hydroxyl group is pendulous or unreacted. Therefore, for diols, only one hydroxyl group is esterified. For triols, no more than two hydroxyl groups are esterified.

[0060] The term "C1-C" is used in this article. n The "alkyl" group refers to a monovalent group containing 1 to n carbon atoms, i.e., the group of an alkane, including straight-chain and branched organic groups. Therefore, "C1-C 18An "alkyl" group refers to a monovalent group containing 1 to 18 carbon atoms, i.e., an alkane group, including straight-chain and branched organic groups. Examples of alkyl groups include, but are not limited to: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; tert-butyl; n-pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In this invention, such alkyl groups may be unsubstituted or may be substituted with one or more halogens. For a given part (R), the permissibility of one or more non-halogen substituents within the alkyl group will be noted in the specification, if applicable.

[0061] The "alkoxy" group refers to a monovalent group represented by -OA, where A is an alkyl group: non-limiting examples are methoxy, ethoxy, and isopropoxy.

[0062] The term "C" used in this article 1-n "Alkyl alcohol" refers to compounds with the general formula ROH, where R is a C12-C12 compound. 1-n alkyl.

[0063] The term "C6-C" is used in this article. 18 The "aryl" group, used alone or as part of a larger group (such as "araneyl"), refers to monocyclic, bicyclic, and tricyclic cyclic systems, wherein the monocyclic system is aromatic, or at least one ring in the bicyclic or tricyclic system is aromatic. Bicyclic and tricyclic systems comprise benzofused 2- to 3-membered carbon rings. In this invention, such aryl groups may be unsubstituted or may be substituted with one or more halogens. For a given part (R), the permissibility of one or more non-halogen substituents within the aryl group will be noted in the specification, if applicable. Exemplary aryl groups include: phenyl; (C1-C4)alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthrayl; and anthracel. C6 aryl groups, particularly phenyl, may be especially preferred.

[0064] The materials and compositions disclosed herein may be defined as "substantially free" of certain compounds, elements, ions, or other similar components. The term "substantially free" means that the compound, element, ion, or other similar component was not intentionally added to the material or composition and is present at most in trace amounts, having no (adverse) effect on the desired properties of the material or composition. An exemplary trace amount is less than 1000 ppm by weight of the material or composition. The term "substantially free" includes situations where the particular compound, element, ion, or other similar component is completely absent from the material or composition, or in any amount that cannot be measured with techniques commonly used in the art.

[0065] The term “anhydrous” as used herein is equivalent to the term “substantially anhydrous.” Water is not intentionally added to a given composition and is present at most in trace amounts, having no (adverse) effect on the desired properties of the composition. Gerbert alcohol

[0066] As described above, the treated emulsion of the present invention comprises, based on the weight of the composition, 1 to 20% by weight of a first defoamer, which consists of: a) at least one C 12 To C 40 a) Guerbert alcohol; and / or b) at least one polyol ester. For example, the treated emulsion contains 1 to 15% by weight or 1 to 10% by weight of: a) at least one C 12 To C 40 Guerbert alcohol; and / or b) at least one polyol ester. Therefore, it is envisioned that the first defoamer can be: composed of at least one C 12 To C 40 The composition of Gelbert alcohol is essentially composed of at least one of the C4 groups. 12 To C 40 The composition includes Gerbert alcohol; or, it contains at least one of the C groups. 12 To C 40 A combination of Gerbert alcohol and one or more polyol esters. Similarly, the first defoamer may consist of at least one of the polyol esters; consist substantially of at least one polyol ester; or comprise at least one polyol ester and one or more C... 12 To C 40 A combination of Gelbert alcohols.

[0067] As used in this article, "Gerbert alcohol" refers to a monofunctional primary alcohol in which at least one branch exists on the carbon atom adjacent to the carbon atom containing the hydroxyl group. Chemically, Gerbert alcohol is described as a 2-alkyl-1-alkanol.

[0068] The Gerbert alcohol can be defined by the following general formula:

[0069] Where: R g and R h Independently for C1-C 20 Alkyl groups; and, R g and R h The sum of the number of carbon atoms ranges from 12 to 40.

[0070] In one implementation, R g and R hThe sum of the carbon atoms is 18 to 40 or 18 to 36. Furthermore, exemplary Gelbert alcohols that can be used herein (either alone or in combination) include, but are not limited to: 2-hexyl-1-decanol; 2-octyl-1-decanol; 2-octyl-1-dodecanol; 2-hexyl-1-dodecanol; 2-decyl-1-tetradecanol; 2-dodecyl-1-hexadecanol; 2-tetradecyl-1-octadecanol; and 2-hexadecyl-1-eicosyl alcohol.

[0071] Exemplary guerbert alcohols are available from commercial sources, including: Isofol® 12, 14T, 16, 18T, 18E, 20, 24, 28, 32, 32T and 36 from Sasol Chemicals; and Pripol® 2033 (C) from Jarchem Industries Inc. 36 (Dimer diol). In addition, the Guerbert alcohol that can be used here can also be synthesized directly.

[0072] The Guerbert reaction is a self-condensation reaction in which an aliphatic primary alcohol is converted into its β-alkylated dimer alcohol while losing an equivalent amount of water: the chain length of the Guerbert alcohol produced by the Guerbert reaction depends in principle on the primary alcohol used as the starting material. When a mixture of primary alcohols with different numbers of carbon atoms is used as reactants, a mixture of Guerbert alcohols will be obtained according to different possible condensation reactions.

[0073] The Guerbert reaction is typically carried out at high temperatures (usually above 100°C) and under conditions where the water produced is removed to minimize product inhibition. A catalytic system is also required: this system should provide dehydrogenation, aldol condensation, dehydration, and hydrogenation, and is typically composed of a strong base and a homogeneous or heterogeneous catalyst. The choice of homogeneous or heterogeneous catalyst determines the molecular weight differences in the Guerbert alcohol mixture, but it is important to note that using a heterogeneous catalyst can facilitate product separation. The Guerbert reaction can also be carried out under a supplemental hydrogen atmosphere to promote the hydrogenation of ketones and aldehydes formed as intermediates.

[0074] As stated above, the Gerbert alcohol disclosed herein can be derived from biorenewable resources.

[0075] More specifically, it is envisioned that at least a portion of the primary alcohols in the Guerbert reaction can be obtained through biomass fermentation: guiding references on such fermentation include WO2009 / 079213 (Gevo Inc.); US 2017 / 0002387 A1 (Retsina et al.). Primary alcohols can be obtained from biorenewable sources through… 14 C and 12 Verification can be made using the ratio of C isotopes.

[0076] When obtained through biomass fermentation, primary alcohols contain impurities, particularly acids and esters. These impurities can neutralize basic compounds (e.g., alkali metal hydroxides or alkoxides) used as cocatalysts, thus impairing the Guerbert reaction. Therefore, these impurities should be removed by appropriate separation or capture methods; solvent extraction and ion exchange may be mentioned in this regard. Primary alcohols can also undergo further pretreatment to remove moisture. a) Polyol esters

[0077] As used herein, the term "polyol ester" refers to a partial or complete ester of a polyol with a saturated or unsaturated fatty acid. For completeness, the term "unsaturated" includes both monounsaturated and polyunsaturated fatty acids. There is no intention to limit the methods of obtaining such polyol esters; therefore, polyol esters can be obtained by acid-catalyzed esterification; base-catalyzed esterification; or transesterification of existing esters. These reactions should generally be carried out under anhydrous conditions and in the presence of a stoichiometric excess of polyol.

[0078] According to this disclosure, preferred polyol esters are polyols having 2 to 6 hydroxyl groups per molecule and C5-C6 hydroxyl groups. 30 Partial or complete esters of saturated or unsaturated straight-chain fatty acids.

[0079] C5-C 30 Illustrative examples of saturated straight-chain fatty acids include, but are not limited to: valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, heptadecanic acid, stearic acid, arachidic acid, behenic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, and bermudaolic acid. (C5-C) 30 Illustrative examples of unsaturated straight-chain fatty acids include, but are not limited to: decenoic acid, palmitoleic acid, oleic acid, trans oleic acid, trans oleic acid, brassic acid, erucic acid, nervonic acid, linoleic acid, pine oil, linolenic acid, tung oil, and arachidonic acid. Illustrative examples of suitable polyols from which polyol esters can be derived include: propane-1,2-diol; propane-1,2,3-triol; trimethylolethane (2-(hydroxymethyl)-2-methylpropane-1,3-diol); trimethylolpropane (2-ethyl-2-(hydroxymethyl)propane-1,3-diol); sucrose; sorbitol; and tripropylene glycol (2-[2-(2-hydroxypropoxy)propoxy]prop-1-ol).

[0080] The following complete esters are preferred: i) C5-C 30Saturated or unsaturated straight-chain fatty acids; and ii) polyols having 2 to 6 hydroxyl groups per molecule and a number-average molecular weight of less than 200 Daltons. Exemplary polyol esters according to this embodiment (which may be used herein and may be used alone or in combination) include: neopentyl glycol dioleate; trimethylolpropane dioleate; trimethylolpropane trioleate; trimethylolpropane triisostearate; 2-ethyl-2-nonanoyloxymethyl-1,3-propanediol dinonanoate (trimethylolpropane trinonanoate); and pentaerythritol tetraoleate. Particular reference may be made to trimethylolpropane trioleate (TMPTO) and trimethylolpropane triisostearate.

[0081] It is recognized that fatty acids from which polyol esters can be derived can be obtained from renewable feedstocks, including microbial oils and oils of algal, plant, and animal origin. The extraction of fatty acids from plants is well-established and conducted on a large scale; furthermore, fatty acid production can be regulated beyond natural limitations through breeding techniques or biotechnological methods involving the transfer of exogenous genes to crops. Microalgae can also provide an important source of fatty acids; it has been shown that fatty acid production can be enhanced by selecting the growth conditions in which microalgae are exposed (particularly salt concentration, light intensity, and temperature). c) Water-immiscible liquid polysiloxanes

[0082] The treated emulsion of the present invention comprises, based on the weight of the emulsion, 1 to 30 wt% of c) at least one water-immiscible liquid polysiloxane. For example, the treated emulsion comprises 5 to 25 wt% or 10 to 25 wt% of c) the at least one water-immiscible liquid polysiloxane. The polysiloxane is characterized by a viscosity of 100 to 100,000 mPa·s, for example, 100 to 50,000 mPa·s or 100 to 20,000 mPa·s, measured at 25°C.

[0083] In an embodiment that does not exclude the above-mentioned viscosity characteristics, the liquid polysiloxane present in the emulsion, or each of them being immiscible with water, has the following general formula (C1): (C1) Where: n is an integer from 20 to 1000; Each R 1 Independently selected from C1-C4 alkyl or C6-C 18 Aryl; and, Each R 2 Independently selected from H, C1-C4 alkyl or C6-C 18 Aryl.

[0084] Regarding compounds of formula C1, the preferred formulation is: each R 1 Independently selected from C1-C2 alkyl or C6 aryl; and each R2 Independently selected from H, C1-C2 alkyl, or C6 aryl. In the exemplary polysiloxane according to formula C1: each R 1 Independently selected from methyl or phenyl; and each R 2 The components are independently selected from H, methyl, or phenyl. The use of one or more poly(phenylmethylsiloxane), polydimethylsiloxane, and polymethylhydrosiloxane in the composition may be mentioned.

[0085] Exemplary commercial polysiloxanes available in this disclosure include: Silfar® 350 and 1000 supplied by Wacker Chemie AG; XIAMETER™ PMX-200 supplied by Dow Corning; and SF 96 supplied by General Electric. d) Hydrophobic particles

[0086] Hydrophobic particles are an optional component of the emulsion disclosed herein, and may comprise 0 to 5% by weight of the total emulsion weight. For example, the treated emulsion may contain 1 to 5% by weight or 1 to 3% by weight of the hydrophobic particles. The hydrophobic particle material should be able to be stably dispersed within the emulsion.

[0087] In a broad sense, there is no intention to particularly limit the shape of the hydrophobic particles used in the emulsion: needle-like, spherical, ellipsoidal, cylindrical, bead-like, cubic, or plate-like particles may be used alone or in combination. Furthermore, it is contemplated that agglomerates of more than one particle type may be used. However, this disclosure is not intended to limit the scope of the present invention, and the hydrophobic particles may be characterized by satisfying at least one of the following conditions: i) a specific surface area of ​​at least 50 m² / g, for example, at least 150 m² / g, as determined by multi-point BET nitrogen adsorption; and ii) a median particle size (Dv50) of 0.01 to 20 μm, for example, 0.1 to 20 μm or 0.5 to 15 μm, as determined by laser diffraction. The hydrophobic particles may have a unimodal or multimodal particle size distribution: in some embodiments, the hydrophobic particles may have a unimodal or bimodal particle size distribution.

[0088] Exemplary hydrophobic particulate materials (which may be used alone or in combination) include: hydrophobic silica, such as hydrophobic fumed silica, hydrophobic precipitated silica, and mixtures thereof; hydrophobic clay; hydrophobic sand; hydrophobic minerals; and hydrophobic carbonaceous particles. The use of hydrophobic particulate silica may be specifically mentioned.

[0089] Hydrophobic particulate materials can be prepared by in-situ hydrophobization under heating and optional catalysis. Guiding references for in-situ hydrophobization include: U.S. Patent No. 3,634,288 (Youngs); U.S. Patent No. 4,008,173 (Davis); EP 0726086A2 (Wacker Chemie AG); and U.S. Patent No. 9,114,333 B2 (Burger et al.).

[0090] Such hydrophobic particulate materials can also be prepared by treating initially hydrophilic particles with a hydrophobic agent and optionally a coupling agent (such as a titanate or zirconate aluminate coupling agent). As is known in the art, the treatment can be carried out in solvent-free (dry processing) or in the presence of a solvent (wet processing), which must be removed by, for example, washing, filtration or distillation.

[0091] Examples of hydrophobic agents include: halosilanes, such as C1-C 12 Alkyl halides and C6-C 18 Aryl halosilanes; C1-C 12 Alkoxysilanes; hydrosilanes, such as C1-C 12 Alkylhydrosilanes and C6-C 18 Arylhydrosilanes; disilazanes such as tetramethyldisilazane; fatty acids having 4 to 28 carbon atoms, such as butyric acid, hexanoic acid, lauric acid, stearic acid, oleic acid, behenic acid; fatty alcohols having 4 to 28 carbon atoms, such as n-butanol, n-pentanol, n-octanol, lauryl alcohol, stearyl alcohol, behenyl alcohol; fatty amines having 12 to 22 carbon atoms, such as dodecylamine, stearylamine, oleylamine; polysiloxanes, such as polymethylhydrosiloxane, polydimethylsiloxane, C6-C 10 Aryl-modified polysiloxanes, C2-C6 alkyl-modified polysiloxanes, amino-modified polysiloxanes; and organosilicon resins, such as MQ resins comprising any combination of triorganosilicon units (M units) and siloxy units (Q units).

[0092] Exemplary sources of hydrophobic particulate materials available here include: Aerosil® R202; Aerosil® R805; Aerosil® R812; Aerosil® R812S; Aerosil® R972; Aerosil® R974; Aerosil® R8200; Aerosil® R972; Aeroxide® LE-1; Aeroxide® LE-2 and Aeroxide® LE-3, supplied by Evonik Degussa GmbH. Similar hydrophobic silica particles are also available from Cabot Corporation. e) Additives and auxiliary ingredients

[0093] The emulsions disclosed herein typically also contain adjuvants and additives that can impart improved properties to these compositions. For example, these adjuvants and additives can impart one or more of the following properties: emulsion stability; defoaming ability; and improved water permeability.

[0094] Such additives and auxiliaries include: surfactants; waxes; stabilizers, including UV stabilizers; biocides; and rheology modifiers for adjusting the viscosity and thixotropy of emulsions, examples of which include thickeners, fillers, solvents, and non-reactive diluents. With respect to any additive or auxiliary material, it is preferred that the flash point of said material is at least 60°C, for example, at least 75°C.

[0095] The emulsions disclosed herein may optionally contain at least one surfactant selected from the group consisting of: anionic surfactants; cationic surfactants; amphoteric surfactants; nonionic surfactants; and mixtures thereof. The emulsion may, for example, contain 0 to 10% by weight or 0 to 8% by weight of surfactant based on the total weight of the emulsion.

[0096] In one embodiment, the surfactant contained in the emulsion comprises, is substantially composed of, or is composed of nonionic surfactants. In one embodiment, said or each surfactant contained in the emulsion may be nonionic. The nonionic surfactant used in the emulsion may be characterized by a number average molecular weight (Mn) of 2,000 to 20,000 Daltons, for example, 2,000 to 10,000 Daltons or 2,000 to 8,000 Daltons. Exemplary nonionic surfactants include: polyethylene oxide, such as PEG 300 or PEG 400; fatty alcohols; primary alcohol (C2-C4) alkoxylates; secondary alcohol (C2-C4) alkoxylates; alkylphenol (C2-C4) alkoxylates; alkylamino (C2-C4) alkoxylates; amine polyglycol condensates, such as Triton® CF-32 supplied by Dow Chemical Company; polyoxy(C2-C3) alkylene fatty acid esters; polysorbates; sodium lauryl sulfate; sorbitan monolaurate; sorbitan monooleate; sorbitan monopalmitate; sorbitan trioleate; and silicone surfactants, such as silicone polyether copolymers. However, nonionic silicone surfactants are not preferred.

[0097] Wax is an optional component of the emulsion disclosed herein, and may comprise 0 to 5% by weight or 0 to 2% by weight of the total weight of the emulsion. Unintentionally limiting the invention, the wax used in this invention should have a softening point of 50 to 150°C and may include one or more of the following: polyethylene with a number-average molecular weight (Mn) of 500 to 7500; petroleum waxes, such as paraffin and microcrystalline waxes; synthetic waxes made by polymerizing carbon monoxide and hydrogen, such as Fischer-Tropsch waxes; polyolefin waxes, including functionalized polyolefin waxes, wherein maleated polyethylene, maleated polypropylene, and maleated (ethylene-co-propylene) are mentioned as examples; and hydrogenated animal, fish, or vegetable oils.

[0098] In this disclosure, "stabilizer" is understood as a material that reduces the tendency of an emulsion to separate into two phases. When present, the stabilizer may comprise up to 5% by weight, for example, from 0.1 to 2.5% by weight, based on the total weight of the emulsion. Examples of standard stabilizers suitable for use herein include: lecithin; phospholipids; and grafted or crosslinked silicone polymers.

[0099] One or more biocides may be present in the emulsion to control microbial growth. The total percentage of biocides may be 0 to 1% by weight, for example, 0.01 to 1% by weight, depending on the weight of the emulsion. Suitable examples of biocides include, but are not limited to: 5-chloro-2-methyl-4-isothiazolin-3-one; 2-methyl-4-isothiazolin-3-one; glutaraldehyde; 2,2-dibromo-3-hypopropanamide; 2-bromo-2-nitropropane-1,3-diol; 1-bromo-1-(bromomethyl)-1,3-propanedionitrile; tetrachloroisophthalonitrile; alkyl dimethyl benzyl ammonium chloride; dimethyl dialkyl ammonium chloride; poly(oxyethylene(dimethylimino)ethylene(dimethylimino)ethylene dichloride; methylene dithiocyanate; 2-decylthioethylamine; tetramethylolphosphine sulfate; dithiocarbamate; cyanodithioiminocarbonate; 2-methyl-5-nitroimidazol-1-ethanol; 2-(2-bromo-2-nitrovinyl)furan; β-bromo-β-nitrostyrene; β-nitrostyrene; β-nitrovinylfuran; 2-bromo-2-bromomethyl Glutronitrile; bis(trichloromethyl)sulfone, S-(2-hydroxypropyl)methylthiosulfonate; tetrahydro-3,5-dimethyl-2H-1,3,5-hydrazine-2-thione; 2-(thiocyanomethylthio)benzothiazole; 2-bromo-4'-hydroxyacetophenone; 1,4-bis(bromoacetoxy)-2-butene; bis(tributyltin)oxide; copper sulfate; (2-tert-butylamino)-4-chloro-6-(ethylamino)-triazine; deca- Dialkylguanidine acetate; dodecylguanidine hydrochloride; cocoalkyl dimethylamine oxide; n-cocoalkyl trimethylenediamine; tetraalkyl phosphorus chloride; 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid; 2-(4-thiazolyl)-benzimidazole; o-phenylphenol; 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline; and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one.

[0100] Thickeners are an optional component of the emulsions disclosed herein, comprising 0 to 5% by weight or 0 to 2% by weight of the total emulsion weight. Exemplary thickeners include, but are not limited to: cellulose thickeners and their derivatives; natural gums, such as guar gum, ebony gum, locust bean gum, carrageenan gum, tragacanth gum, and xanthan gum; starch; stearates; fatty alcohols; hydrophobically modified alkali-soluble emulsion polymers (HASE); hydrophobically modified polyurethane-ethoxylated resins (HEUR); and acrylic polymers and crosslinking polymers. The use of cellulose thickeners and their derivatives may be specifically mentioned, examples of which include: carboxymethyl hydroxyethyl cellulose; cellulose, hydroxybutyl methyl cellulose; hydroxyethyl cellulose; hydroxypropyl cellulose; hydroxypropyl methyl cellulose; methyl cellulose; microcrystalline cellulose; and sodium cellulose sulfate.

[0101] If the viscosity can be effectively adjusted, the presence of a co-solvent and a non-reactive diluent in the emulsion of the present invention is not excluded. When present, the co-solvent or diluent should comprise or consist of a non-polar, water-immiscible compound. Such compounds may be selected from: alkanes (R-H); cycloalkanes; branched alkanes; aromatic hydrocarbons (Ar-H); haloalkanes (R-X); and mixtures thereof. Exemplary but non-limiting non-polar, water-immiscible solvents (which may be used alone or in combination) include n-pentane, n-hexane, cyclohexane, n-heptane, isooctane, trimethylpentane, toluene, xylene, and benzene.

[0102] In addition, based on the total weight of the emulsion, the solvent and non-reactive diluent together preferably account for less than 10% by weight, particularly less than 5% by weight or less than 2% by weight. Illustrative implementation plan for treating emulsions

[0103] In a first illustrative embodiment, an aqueous emulsion is provided for treating an aqueous process stream in a pulp and paper mill, the treated emulsion comprising water and, based on the weight of the emulsion: The first defoamer, comprising 1 to 15% by weight, consists of the following: a) At least one C 12 To C 40 Guerbert alcohol is represented by the following formula:

[0104] Where: R g and R h Independently for C1-C 20 Alkyl groups; and, R g and R h The sum of the number of carbon atoms ranges from 12 to 40; c) 5 to 25% by weight of at least one water-immiscible liquid polysiloxane having the general formula (C1). (C1) Where: n is an integer from 20 to 1000; Each R 1 Independently selected from C1-C4 alkyl or C6-C 18 Aryl; and, Each R 2 Independently selected from H, C1-C4 alkyl or C6-C 18 Aryl; and, 1 to 5% by weight of d) hydrophobic particles, wherein the hydrophobic particles are characterized by a median particle size (Dv50) of 0.01 to 10 μm as determined by laser diffraction.

[0105] In a second illustrative embodiment, an aqueous emulsion is provided for treating aqueous process streams in a pulp and paper mill, the treated emulsion comprising water and, based on the weight of the emulsion: The first defoamer, comprising 1 to 15% by weight, consists of the following: a) At least one polyol and C5-C 30 Partial or complete esters formed from saturated or unsaturated straight-chain fatty acids, wherein the polyol has 2 to 6 hydroxyl groups per molecule and a number-average molecular weight of less than 200 Daltons; c) 5 to 25% by weight of at least one water-immiscible liquid polysiloxane having the general formula (C1). (C1) Where: n is an integer from 20 to 1000; Each R 1 Independently selected from C1-C4 alkyl or C6-C 18 Aryl; and, Each R 2 Independently selected from H, C1-C4 alkyl or C6-C 18 Aryl; and, 1 to 5% by weight of d) hydrophobic particles, wherein the hydrophobic particles are characterized by a median particle size (Dv50) of 0.01 to 10 μm as determined by laser diffraction.

[0106] Regarding this second illustrative embodiment, the first defoamer preferably contains or consists of trimethylolpropane trioleate (TMPTO). Methods and Applications

[0107] To form the defined emulsion, the components are brought together and mixed. It is important that mixing ensures a uniform distribution of the components within the emulsion: thorough and effective mixing is crucial for achieving a homogeneous distribution of any constituent particulate material. Therefore, mixing is typically not performed manually, but rather using static mixers, dynamic mixers, colloid mills, rotor-stator homogenizers, or ultrasonic probes. While the order in which the components are mixed and the mixing temperature may not usually be critical, they can certainly be adjusted to ensure the homogeneity of the mixture. In some embodiments, the mixing process can be carried out under reduced pressure to prevent air (e.g., air present in highly dispersed fillers) from being incorporated.

[0108] If necessary, the treatment emulsion can be prepared in advance before application. However, in an interesting alternative embodiment, the concentrated treatment composition can be prepared first by mixing the components with water in a proportion equal to the actual amount of water used in the treatment emulsion; the concentrated treatment composition can then be diluted with the remaining water just before contact with the foaming medium or process stream. It is believed that such concentrated compositions can be prepared and stored as single-component concentrates (convertible by dilution with water only) or multi-component concentrates (where two or more components must be combined and diluted to form a complete working emulsion according to this disclosure). Any dilution can be achieved simply by adding water, particularly deionized and / or demineralized water, under stirring. Similarly, the emulsion can be prepared in a rinsing stream, wherein one or more streams of concentrate are injected into a continuous stream of water.

[0109] In one embodiment, the treatment emulsion disclosed herein is added to or metered into an aqueous foamable medium. The method of addition or metering is not intended to be limited and can indeed be manual or automated. Furthermore, the emulsion can be metered in a batch process, either continuously or intermittently. Those skilled in the art will be able to determine the appropriate dosage and contact time based on the foamable medium being treated, which may be determined through trial and error if necessary. A typical contact time is envisioned to be less than 60 minutes.

[0110] Exemplary methods of adding or metering emulsion streams for processing one or more process streams in a pulping and papermaking system include: using a tank dilution line; spraying, including curtain spraying, compressed air spraying, and electrostatic spraying; introducing into a storage tower or tank supplying a given process stream, such as a fresh water tank, a warm water tank, and a wash water tank; introducing into a headbox; and mixing the emulsion stream with the process stream. In the last mixing operation, the emulsion may be provided via a short loop connected at an angle to the container carrying the process stream.

[0111] In some implementations, the contact time between the emulsion and the process flow can be 1 to 60 minutes, for example 1 to 40 minutes or 1 to 20 minutes.

[0112] Preferably, the treated emulsion according to this disclosure is added to the aqueous process stream such that the amount of the first defoamer is 0.1 to 1000 ppm by weight of the total weight of the process liquid to be defoamed. For example, the amount of treated emulsion added may be: 0.5 to 500 ppm by weight or 1 to 200 ppm by weight of the first defoamer based on the total weight of the aqueous process stream. Another expression (not intended to be mutually exclusive with the previously given) is: the treated emulsion is added such that the amount of the first defoamer is 0.5 to 500 μl or 1 to 200 μl per liter of aqueous process stream.

[0113] The following examples illustrate the present invention and are not intended to limit the scope of the invention in any way. Example

[0114] The following materials were used in the embodiments: Isofol® 20: 2-Octyl-1-dodecanool, supplied by Sasol Chemicals.

[0115] TMPTO: Trimethylolpropane trioleate, supplied by Sigma Aldrich.

[0116] Nopcomaster ENA 2000: A silicone / isopropyl myristate (IPM) based defoamer supplied by Solenis.

[0117] The following test procedures were performed to evaluate the defoaming emulsion.

[0118] Emulsion Preparation Procedure: The aqueous emulsions described below are provided as commercially available water-dilutable products or prepared in situ. The addition of the diluent (water) and any other ingredients is carried out under stirring. Visually perceptible phase separation is not permitted before use of the emulsion.

[0119] Foam tank testing procedure: i) To heat the foam tank testing equipment (7cm in diameter; 45cm in height) to or near the test temperature (80-85°C), preheated process liquid or water (500-800 ml) is pumped into all its pipelines. The pumps used are not continuously running. The introduced liquid is allowed to stand in the pipeline for 30 to 60 seconds. Then the pipeline is drained and refilled with 500 to 600 ml of fresh black liquor.

[0120] ii) Start the recirculation pump to establish a foam height for the introduced liquid. Adjust the recirculation rate as needed to achieve a foam level of 25 to 40 cm (10-16 inches) within 10 to 20 seconds. The foam rise rate varies depending on the quality of the black liquor. To obtain an effective high rise rate, excessive liquid temperature loss must be prevented, and pump cavitation and liquid flow instability must be avoided. The selected foam level is designated as FH0 for all subsequent runs.

[0121] iii) At t=0, use a micropipette to inject 25 μl of the control defoaming emulsion into the filtrate stream at the top of the foam tank: the pump should remain running at this time. Note that the treatment emulsion should be injected directly into the liquid stream, but the micropipette should not be pushed into the liquid: dripping the defoaming emulsion onto the top of the foam or injecting it only into the edge of the stream will result in inconsistent results.

[0122] iv) Immediately after injecting the defoaming emulsion, start a timer or stopwatch (t=0) and record the foam level at 5-second intervals, accurate to the centimeter, up to 125 seconds, provided the foam level does not exceed the initial level (FH0). The foam level decreases upon initial injection of the defoaming emulsion. The percentage of foam knockdown (%) is determined using the following formula: 100 (FH0 -FH min ) / FH0, where FH min This is the minimum foam height recorded within the first 30 seconds after the defoamer is injected (t=30). The time (t) at which this minimum value is reached is also recorded. min ).

[0123] v) At 125 seconds (t=125) or the recording time when the foam reaches its initial level, the pump is turned off. Various parameters characterizing foam persistence can be measured. Foam persistence (P...) 1 This reflects the growth rate of foam height from when the foam is knocked down until t=125s, according to the formula (FH). 125 - FH min ) / (125 - t min ) Determined, where FH 125 This is the foam height recorded at t=125 seconds. Duration (P) 2 The term , s) can also be expressed below as the foam reaching its maximum height (FH) after the foam breaks due to the addition of defoamer. max The time required. Duration (P) 3 The percentage can also be expressed below as the relative deviation of the integral area under the measured foam height versus time curve relative to the control formulation (set as 100%) within the range of 75 to 125 seconds (75 ≤ t ≤ 125).

[0124] vi) After the pump is turned off, continue timing until 60 seconds or the time it takes for the foam to dissipate to the liquid surface (whichever is earlier): record the dissipation time (foam bursting) where applicable, and record any observations on foam stability, the final foam level, and whether there are deposits on the walls of the test equipment.

[0125] vii) In the comparison of defoamer FH min If the depth is not less than 15cm, adjust the dosage of the defoaming emulsion upwards and repeat the knockdown test. Conversely, if the FH of the control defoamer is lower... min If the foam is less than 15cm, but remains below the 15cm mark after 60 seconds (t=60), reduce the dosage of defoamer and repeat the knockdown test. This adjustment is necessary to ensure product differentiation relative to the control product.

[0126] viii) After testing with the control defoamer, drain the liquid from the equipment. Repeat the above test procedure for each defoaming emulsion to be tested—starting with the equipment preheating step. If the time to build up initial foam height exceeds 30 seconds, stop the test and clean the equipment again. If the build-up time remains a problem after repetition, this indicates a change in liquid quality, and the test cycle must be repeated.

[0127] ix) The source of the black liquor and the liquid flow rate through the equipment set by the pump should be consistent with those used for the control defoamer. The product dosage of the defoaming emulsion to be tested should be adjusted to achieve an equivalent active ingredient dosage relative to the stated dosage of the control product.

[0128] x) Each defoaming emulsion to be screened was tested three times in random order. The final data (knockout rate; persistence; dissipation time) for each emulsion were then averaged and listed in the table below, where applicable. Example 1

[0129] Prepare emulsions according to Table 1 below: the percentages are weight percentages based on the total weight of the emulsion.

[0130] Table 1

[0131] For both the control formulation and formulation 1, three foam pool tests (I, II, III) were performed.

[0132] I: In the first test, the defoaming effect of each formulation was evaluated using Southern Cork Black Liquor from Mill 1 at a test temperature of 85°C: the emulsion dosage was 80 μl per liter of treatment liquid.

[0133] II: In the second test, the defoaming effect of each formulation was evaluated using Southern Cork Black Liquor from Plant 2 at a test temperature of 75°C: the emulsion dosage was 80 μl per liter of treatment solution.

[0134] III: In the third test, the defoaming effect of each formulation was evaluated using Northern Cork Black Liquid from the United States at a test temperature of 75°C: the emulsion dosage was 60 μl per liter of treatment liquid.

[0135] The foam pool test results (I, II, III) of these formulations are shown in Figures 1a(I), 1b(II), and 1c(III), respectively. In the first and second tests, formulation 1 showed near-equivalent (I) or better (II) defoaming effects compared to the control formulation throughout the test. In the third test, formulation 1 showed significantly improved initial performance (knockdown rate) compared to the control formulation. Example 2

[0136] Prepare emulsions according to Table 2 below.

[0137] Table 2

[0138] The foam pool test procedure detailed above was conducted using pine black liquor from Brazil at 85°C: the dosage of the active defoamer was 13 ppm by weight, based on the weight of the treated liquor. The test results are shown in Table 3 below. Table 3 Example 3

[0139] Prepare emulsions according to Table 4 below.

[0140] Table 4

[0141] The foam pool test procedure detailed above was performed using Mercer Rosenthal cork black liquor at 85°C: the dosage of the active defoamer was 50 ppm by weight, based on the weight of the treated liquor. The test results are shown in Table 5 below. Table 5

[0142] Prepare emulsions according to Table 6 below.

[0143] Table 6

[0144] The foam pool test procedure detailed above was performed using Type 4.4 cork-based artificial black liquor at 85°C: the emulsion dosage was 50 μl per liter of treatment solution. The foam pool test results for these formulations are shown in the appendix. Figure 2 The figure clearly shows that both TMPTO and C36 Guerbert alcohol can replace isopropyl myristate as active defoamers without impairing emulsion performance. The presence of TMPTO and C36 Guerbert alcohol (Isofol® 20) appears to contribute to improved knockdown performance. Example 5

[0145] Prepare the emulsion according to Table 7 below.

[0146] Table 7

[0147] The foam pool test procedure detailed above was performed using Type 1.2 artificial hardwood black liquor at 82°C: the emulsion dosage was 40 ppm by weight based on the weight of the treatment liquor. The foam pool test results for these formulations are shown in the appendix. Figure 3 Adding TMPTO or 2-octyl-1-dodecanool can improve the persistence of defoaming.

[0148] It should be understood that various changes and modifications to the exemplary embodiments described herein will be apparent to those skilled in the art. These changes and modifications can be made without departing from the scope of the invention and without diminishing its intended advantages. Therefore, it is intended that these changes and modifications be covered by the appended claims. Furthermore, it should be understood that the features of the dependent claims may be embodied in the compositions and methods of each independent claim.

[0149] Many modifications and other embodiments of the invention set forth herein will come to mind once those skilled in the art have benefited from the teachings in the foregoing description and the associated drawings. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, and that these modifications and other embodiments are intended to be included within the scope of the appended claims.

Claims

1. A method for treating an aqueous foamable medium, the method comprising contacting the aqueous foamable medium with a defoamer, the defoamer comprising: a) At least one C 12 To C 40 Guerbert alcohol; and / or, b) At least one polyol ester.

2. The method according to claim 1, wherein the defoamer comprises at least one C having the following formula: 12 To C 40 Guerbert alcohol: in: R g and R h Independently for C1-C 20 Alkyl groups; and, R g and R h The sum of the number of carbon atoms ranges from 12 to 40.

3. The method according to claim 2, wherein R g and R h The sum of the number of carbon atoms ranges from 18 to 40.

4. The method according to claim 2, wherein R g and R h The sum of the number of carbon atoms ranges from 18 to 36.

5. The method according to claim 2, wherein the defoamer comprises at least one C 12 To C 40 Guerbert alcohol is selected from: 2-hexyl-1-decanol; 2-octyl-1-decanol; 2-octyl-1-dodecanol; 2-hexyl-1-dodecanol; 2-decyl-1-tetradecanol; 2-dodecyl-1-hexadecanol; 2-tetradecyl-1-octadecanol; and 2-hexadecyl-1-eicosyl alcohol.

6. The method according to any one of claims 1 to 5, wherein the defoamer comprises at least one polyol and C5-C 30 Partial or complete esters formed from saturated or unsaturated straight-chain fatty acids, wherein each molecule of the polyol has 2 to 6 hydroxyl groups.

7. The method according to claim 6, wherein the defoamer comprises at least one polyol ester selected from: neopentyl glycol dioleate; trimethylolpropane dioleate; trimethylolpropane trioleate; trimethylolpropane triisostearate; 2-ethyl-2-nonanoyloxymethyl-1,3-propanediol dinonanoate (trimethylolpropane trinonanoate); and pentaerythritol tetraoleate.

8. The method according to claim 7, wherein the defoamer comprises trimethylolpropane trioleate (TMPTO) and / or trimethylolpropane triisostearate.

9. The method according to any one of claims 1 to 8, wherein the aqueous foamable medium is a process flow of a pulp and paper mill.

10. The method according to claim 9, wherein the contact time between the defoamer and the aqueous process flow is 1 to 60 minutes.

11. The method according to claim 10, wherein, Based on the total weight of the aqueous process flow, the dosage of defoamer in contact with the aqueous process flow is 0.1 to 1000 ppm by weight.

12. The method according to claim 11, wherein, Based on the total weight of the aqueous process flow, the dosage of defoamer in contact with the aqueous process flow is 0.5 to 500 ppm by weight.

13. An aqueous emulsion for treating aqueous foamable media, said emulsion comprising water and, based on the weight of the emulsion: The first defoamer, comprising 1 to 20% by weight, consists of the following: a) At least one C 12 To C 40 Guerbert alcohol; and / or b) At least one polyol ester; c) at least one water-immiscible liquid polysiloxane, ranging from 1 to 30% by weight; and, 0 to 5% by weight of d) hydrophobic particles.

14. The processed emulsion according to claim 13, comprising water and, based on the weight of the emulsion: The first defoamer, comprising 1 to 15% by weight, consists of the following: a) At least one C 12 To C 40 Guerbert alcohol; and / or b) At least one polyol ester; c) at least one water-immiscible liquid polysiloxane, comprising 5 to 25% by weight; and 1 to 5% by weight of d) hydrophobic particles.

15. The treated emulsion according to claim 13 or 14, wherein the first defoamer comprises or is composed of at least one C having the following formula: 12 To C 40 Guerbert alcohol composition: Where: R g and R h Independently for C1-C 20 Alkyl groups; and, R g and R h The sum of the number of carbon atoms ranges from 12 to 40.

16. The treated emulsion according to claim 15, wherein R g and R h The sum of the number of carbon atoms ranges from 18 to 40.

17. The treated emulsion according to claim 15, wherein R g and R h The sum of the number of carbon atoms ranges from 18 to 36.

18. The treated emulsion of claim 15, wherein the first defoamer comprises or is composed of at least one C 12 To C 40 The composition of the gerbert alcohol is selected from: 2-hexyl-1-decanol; 2-octyl-1-decanol; 2-octyl-1-dodecanol; 2-hexyl-1-dodecanol; 2-decyl-1-tetradecanol; 2-dodecyl-1-hexadecanol; 2-tetradecyl-1-octadecanol; and 2-hexadecyl-1-eicosyl alcohol.

19. The treated emulsion according to any one of claims 13 to 18, wherein the first defoamer comprises or is composed of at least one polyol and C5-C 30 The polyol is composed of partial or complete esters formed from saturated or unsaturated straight-chain fatty acids, and each molecule of the polyol has 2 to 6 hydroxyl groups.

20. The treated emulsion of claim 19, wherein the first defoamer comprises or is composed of at least one polyol ester selected from: neopentyl glycol dioleate; trimethylolpropane dioleate; trimethylolpropane trioleate; trimethylolpropane triisostearate; 2-ethyl-2-nonanoyloxymethyl-1,3-propanediol dinonanoate (trimethylolpropane trinonanoate); and pentaerythritol tetraoleate.

21. The treated emulsion of claim 20, wherein the first defoamer comprises or is composed of trimethylolpropane trioleate (TMPTO) and / or trimethylolpropane triisostearate.

22. The processed emulsion according to any one of claims 13 to 21, wherein the polysiloxane of part c) is characterized by a viscosity of 100 to 100,000 mPa·s measured at 25°C.

23. The treated emulsion according to any one of claims 13 to 22, wherein the polysiloxane in part c) or each of them has the following general formula (C1): (C1) in: n is an integer between 20 and 1000; Each R 1 Independently selected from C1-C4 alkyl or C6-C 18 Aryl; and, Each R 2 Independently selected from H, C1-C4 alkyl or C6-C 18 Aryl.

24. The treated emulsion according to claim 23, wherein in formula C1: Each R 1 Independently selected from C1-C2 alkyl or C6 aryl; and, Each R 2 It is independently selected from H, C1-C2 alkyl or C6 aryl.

25. The treated emulsion according to claim 23, wherein in formula C1: Each R 1 Independently selected from methyl or phenyl; and, Each R 2 It is independently selected from H, methyl, or phenyl.

26. The processed emulsion according to claim 23, wherein portion c) comprises at least one polysiloxane selected from: poly(phenylmethylsiloxane), polydimethylsiloxane, and polymethylhydrosiloxane.

27. The processed emulsion according to any one of claims 13 to 26, wherein the hydrophobic particles are characterized in that the median particle size (Dv50) measured by laser diffraction is 0.01 to 10 μm.

28. The processed emulsion according to any one of claims 13 to 27, wherein portion d) comprises or is composed of hydrophobic particulate silica.

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