Defoamer composition, method for preparing defoamer composition and method for defoaming industrial process stream

Abstract

A defoamer composition, a method for preparing a defoamer emulsion, and a method for defoaming an industrial process stream. The defoamer composition comprises a microcrystalline wax and a long chain fatty alcohol in an aqueous emulsion. The defoaming compositions can be effectively and efficiently used in relatively high temperature industrial process streams.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the priority of U.S. Application Serial No. 18 / 059,975, filed on November 29, 2022, the content of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to defoaming compositions and their uses, as well as methods for preparing defoaming compositions. The defoaming compositions are particularly suitable for the pulp and paper industry, as well as any other processing industry where foaming is not desired. Background Art

[0004] Defoamers are widely used in many industries, including but not limited to the pulp, paper, petroleum, textile, and mining industries, water treatment, paints and coatings, food and beverage processing, and agriculture.

[0005] Defoamers typically consist of defoaming agents (such as but not limited to ethylenebis(stearamide) (EBS) and / or hydrophobic silica), carrier fluids, and various other additives.

[0006] Defoamers mainly have two functions, which are defoaming and preventing foaming. The rapid knockdown and persistence of a defoamer provide important information about the performance of the defoamer. The formation of foam in a solution reduces the density of the solution. The addition of a defoamer destroys the foam, and the density of the solution increases again. The rate of density increase due to the addition of the defoamer indicates the speed at which the defoamer acts, which is referred to as the rapid knockdown phase. The faster the rapid knockdown, the more effective the defoamer; however, the defoaming effect is temporary and over time, the defoamer begins to fail, and as the foam begins to regenerate, the density begins to decrease again. The duration or persistence of the defoamer indicates the time for which the defoamer acts. The longer the duration or persistence of the defoamer, the more effective the defoamer. An ideal defoamer should have rapid knockdown and long duration or be able to persist for a long time, i.e., the foam disappears rapidly after the addition of the defoamer, and it takes a long time for the foam to regenerate.

[0007] Currently in the pulp and paper industry, silicone-based defoamers are preferred compared to other defoamers due to lower dosage requirements and cost-effectiveness.

[0008] Nevertheless, silicone-based defoamers themselves also pose inherent challenges and problems. Some of these challenges are characterized by environmental and regulatory, transfer / deposition, and cost-benefit issues and are further associated with complex manufacturing processes. However, in order to extend the duration of silicone-based defoamers, larger amounts of these defoamers will need to be used in the process. Since there are relatively high amounts of hydrophobic components (such as silicone compounds) in the process, this will in turn lead to additional inherent problems. Hydrophobic components tend to adhere to the fibers, and excessive hydrophobic components will require additional washing steps later in the process. Therefore, it is necessary to limit the amount of hydrophobic components in the final fiber, and excessive silicone-based defoamers cannot be a reliable solution to the limited duration of defoamers.

[0009] For a long time, various industries have been seeking alternatives to silicone-based defoamers, partly aiming to overcome the challenges encountered by silicone-based defoamers so far. Water-based defoamers are an alternative, but their applicability is limited. Water-based defoamers typically contain long-chain fatty alcohols and hydrocarbon oils or waxes or both. These defoamers are formulated as oil-in-water emulsions by means of an emulsification process. However, existing water-based defoamers still pose challenges, including a significant loss of defoaming efficiency and effectiveness at high temperatures (75 °C or higher), non-compliance with environmental or other regulations, or lack of storage stability, or a combination thereof.

[0010] Therefore, there is still a need to develop new and effective defoamers that are environmentally friendly, cost-effective, easy to prepare, and stable, but at the same time are characterized by showing a longer duration even at high temperatures along with showing a rapid defoaming phase. SUMMARY OF THE INVENTION

[0011] The present invention provides a defoamer composition comprising an aqueous phase and an organic phase emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long-chain fatty alcohol, the microcrystalline wax having a melting point of at least about 83 °C and the at least one long-chain fatty alcohol having a carbon chain length of C 22 or longer and a melting point of at least about 62 °C. Embodiments of the present invention exhibit improved environmental regulatory compliance, improved food and beverage regulatory compliance, higher storage stability, or enhanced defoaming performance (even at high temperatures), or a combination thereof.

[0012] The present invention also provides a method for defoaming in an industrial process stream, the method comprising the step of adding to the industrial process stream an amount of a defoamer composition effective to defoam or prevent foaming in the industrial process stream, the defoamer composition comprising an aqueous phase and an organic phase emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long-chain fatty alcohol, the microcrystalline wax having a melting point of at least about 83 °C and the at least one long-chain fatty alcohol having a carbon chain length of C22 or longer and having a melting point of at least about 62 °C.

[0013] In addition, provided herein is a method for preparing an antifoam composition in an amount effective to defoam or prevent foaming in an industrial process stream, the method comprising the steps of: (1) heating a mixture comprising water, at least one microcrystalline wax, and at least one long-chain fatty alcohol sufficiently to liquefy any solids, the microcrystalline wax having a melting point of at least about 83 °C, and the at least one long-chain fatty alcohol having a carbon chain length of C 22 or longer and having a melting point of at least about 62 °C, and (2) adding at least one emulsifier and at least one surfactant to the mixture; and (3) homogenizing the mixture to form an emulsion comprising an organic phase emulsified into an aqueous phase.

[0014] Additional aspects will be set forth in part in the description that follows, and in part will be obvious from the specification, or may be learned by practice of the aspects described herein. The advantages described herein can be realized and attained by the elements and combinations particularly pointed out in the appended claims. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A FEAT result graph of an antifoam composition according to an embodiment of the present invention together with comparative examples tested at 75 °C is depicted.

[0016] Figure 2 Depicts as used to create Figure 1 A FEAT bar graph of the defoaming performance of the same antifoam composition according to an embodiment of the present invention together with comparative examples tested at 75 °C for the graph.

[0017] Figure 3 A FEAT result graph of an antifoam composition according to an embodiment of the present invention together with comparative examples tested at 85 °C is depicted.

[0018] Figure 4 Depicts as used to create Figure 3 A FEAT bar graph of the defoaming performance of the same antifoam composition according to an embodiment of the present invention together with comparative examples tested at 85 °C for the graph.

[0019] Figure 5 A FEAT result graph of an antifoam composition according to an embodiment of the present invention tested at 85 °C to show the effect of dosage is depicted.

[0020] Figure 6 A graph of the storage stability of the viscosity over time of an antifoam composition according to an embodiment of the present invention tested at 5 °C, room temperature, and 40 °C is depicted. Detailed Embodiments

[0021] Embodiments of the present invention described herein include defoaming compositions that are water-based emulsions and can be used effectively and efficiently in industrial process streams at relatively high temperatures. Embodiments of the present invention include defoaming compositions that exhibit improved environmental regulatory compliance, improved food and beverage regulatory compliance, higher storage stability, or enhanced defoaming performance (even at high temperatures), or combinations thereof.

[0022] Defoaming Composition

[0023] Generally, a defoaming composition according to an embodiment of the present invention comprises an aqueous phase and an organic phase emulsified in the aqueous phase, and comprises at least one long-chain fatty alcohol and at least one microcrystalline wax and at least one long-chain fatty alcohol, the microcrystalline wax having a melting point of at least about 83 °C, and the at least one long-chain fatty alcohol having a carbon chain length of C 22 or longer and a melting point of at least about 62 °C.

[0024] Suitable long-chain fatty alcohols according to embodiments of the present invention include C 22 to C 28 , or even longer monohydric to trihydric alcohols. These alcohols include natural fatty alcohols and synthetic fatty alcohols. The fatty alcohols may be selected from the group consisting of: C 22 alcohol, C 24 alcohol, C 26 alcohol, C 28 alcohol, C 30 alcohol, C 32 alcohol and C 34 alcohol, each having a single carbon atom number. Alternatively, the fatty alcohol may be selected from mixed fatty alcohols having different carbon atom numbers and a carbon chain length of at least C 22 . If synthetic alcohols are used, the fatty alcohols may be obtained from alkyl aluminum oxides by the Ziegler process and may also be obtained by hydroformylation. Generally, the fatty alcohols obtained by such processes are mixed saturated straight-chain alcohols.

[0025] The melting point of suitable long-chain fatty alcohols according to embodiments of the present invention may be at least about 62 °C, or about 62 °C to about 67 °C.

[0026] The defoaming agent composition according to an embodiment of the present invention may comprise at least one long-chain fatty alcohol present in the defoaming agent composition in an amount of about 8% to about 30% by weight or about 10% to about 20% by weight based on the weight of the defoaming agent composition.

[0027] Suitable microcrystalline waxes according to embodiments of the present invention include microcrystalline waxes having a melting point of about 83°C to about 99°C, or about 85°C to about 99°C, or about 90°C to about 99°C, or higher than about 90°C. The defoaming agent composition according to embodiments of the present invention may comprise at least one microcrystalline wax in an amount of about 5% to about 25% by weight or about 6% to about 15% by weight based on the weight of the defoaming agent composition in the defoaming agent composition.

[0028] The defoaming agent composition according to embodiments of the present invention may further comprise at least one emulsifier or a combination of a plurality of emulsifiers. Suitable emulsifiers according to embodiments of the present invention include surfactants, which may be anionic surfactants or nonionic surfactants or both. In addition, suitable surfactants according to embodiments of the present invention include polyethers. The nonionic surfactant may be present in the defoaming agent composition according to embodiments of the present invention in an amount of about 0.01% to about 10% by weight of the defoaming agent composition. Suitable anionic surfactants according to embodiments of the present invention may include sodium dodecyl polyoxyethylene ether sulfate, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium hexadecyl sulfate, sodium hexadecyl benzene sulfonate, and sodium dodecyl diphenyl ether disulfonate, etc. The anionic surfactant may be present in the defoaming agent composition according to embodiments of the present invention in an amount of about 0.01% to about 5% by weight of the defoaming agent composition.

[0029] The defoaming agent composition according to embodiments of the present invention may further have a bioenergy content of at least 50% or at least 60%. The bioenergy content means the amount of bio-based carbon in a material or product, expressed as a percentage of the weight (mass) of the total organic carbon in the material or product, which percentage is determined by testing a representative sample using the American Society for Testing and Materials specification D6866. Bio-based carbon means new carbon (such as carbon directly from plants) rather than fossil fuel-based organic carbon. The total organic carbon includes both new carbon and fossil fuel-based carbon.

[0030] The defoaming agent composition according to an embodiment of the present invention can act as a defoaming agent at a temperature of at least 75 °C, or at least 85 °C or at least 90 °C, or at a temperature of 75 °C to 95 °C or at a temperature of 85 °C to 95 °C. Such high-temperature performance is unexpected because conventional water-based defoaming agent compositions generally act well as defoaming agents at relatively low temperatures (such as below 75 °C) and do not act as defoaming agents at higher temperatures (such as 75 °C or higher). Even at a temperature of 75 °C to 95 °C, based on FEAT results, the defoaming agent composition according to an embodiment of the present invention also exhibits rapid defoaming and duration or persistence in terms of foam suppression.

[0031] The defoaming agent composition according to an embodiment of the present invention is relatively stable, which means that they can still maintain most of their viscosities during an extended storage time. For example, when the embodiment of the present invention is stored at a temperature of about 40 °C for up to 100 days, the embodiment of the present invention exhibits a viscosity < 1500 cP; or when it is stored at a temperature of about 23 °C for up to 100 days, it exhibits a viscosity < 900 cP; or when it is stored at a temperature of about 5 °C for up to 100 days, it exhibits a viscosity < 800 cP.

[0032] The defoaming agent composition according to an embodiment of the present invention can be free of one or more of oil, silicone oil, silica, or ethylenebisstearamide. The defoaming agent composition according to an embodiment of the present invention can be free of oil, silicone oil, silica, or ethylenebisstearamide or any combination thereof. Therefore, the defoaming agent composition according to an embodiment of the present invention is more likely to meet regulatory requirements, such as meeting environmental regulations or Food and Drug Administration or BfR regulations, and thus is applicable to food and beverage applications.

[0033] Method for preparing a defoaming composition

[0034] Generally, the defoaming composition according to an embodiment of the present invention can be prepared by a method including the following steps: sufficiently heating a mixture containing water, at least one microcrystalline wax, and at least one long-chain fatty alcohol to liquefy any solids, the melting point of the microcrystalline wax being at least about 83 °C, and the carbon chain length of the at least one long-chain fatty alcohol being C 22 or longer and the melting point being at least about 62 °C; adding at least one emulsifier and at least one surfactant to the mixture; and homogenizing the mixture to form an emulsion containing an organic phase emulsified into an aqueous phase.

[0035] The emulsion of the present invention comprises organic phase droplets in a continuous aqueous phase. The organic phase droplets comprise at least one long-chain fatty alcohol and at least one microcrystalline wax. The term "emulsion" refers to a combination of at least two liquids, where one liquid is present as droplets in the other liquid. See, IUPAC, Compendium of Chemical Terminology: IUPAC Recommendations, 2nd Edition, compiled by A.D. McNaught and A. Wilkinson, Blackwell, Oxford (1997).

[0036] The emulsion can comprise any amount of the aqueous phase and the organic phase by weight, as long as it is beneficial for defoaming.

[0037] The method for preparing a defoaming agent composition according to an embodiment of the present invention further comprises adding a sizing agent, such as fortified rosin, to the mixture before the homogenization step.

[0038] The method for preparing a defoaming agent composition according to an embodiment of the present invention further comprises adding a thickening agent to the emulsion. The thickening agent according to an embodiment of the present invention is mainly used to adjust the viscosity of the emulsion to improve the stability of the emulsion. Suitable thickening agents according to an embodiment of the present invention include xanthan gum, guar gum, polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylic acid, polyacrylamide, polyacrylate, etc. The thickening agent can be present in the defoaming agent composition according to an embodiment of the present invention in an amount of about 0.1% to about 2.0% by weight of the defoaming agent composition or about 0.2% to about 1.0% by weight of the defoaming agent composition.

[0039] The method of preparing an antifoam composition according to an embodiment of the present invention further comprises adding an antimicrobial agent to the emulsion. The antimicrobial agent is an antimicrobial chemical that can prevent, render harmless, or exert control over any harmful organisms. Examples of non-oxidizing antimicrobial agents useful in the compositions of the present invention (particularly for pulp and paper processes) include, for example, 2-bromo-2-nitropropane-1,3-diol, 5-chloro-2-methyl-4-isothiazolin-3-one, DBNPA, n-octyl-isothiazolin-3-one, MBT, quaternary ammonium compounds, THPS, and glutaraldehyde. In an embodiment, the antimicrobial agent is selected from the group consisting of glutaraldehyde, 2,2-dibromo-3-nitrilopropionamide (DBNPA), 2-bromo-2-nitropropane-1,3-diol (bronopol), 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT), n-alkyl dimethyl benzyl ammonium chloride, didodecyl dimethyl ammonium chloride (DDAC), alkenyl dimethyl ethyl ammonium chloride, tetrakis (hydroxymethyl) phosphonium sulfate (THPS). The antimicrobial agent is typically present in the emulsion in an amount of from about 0.05% to about 1.0% by weight of the emulsion or from about 0.1% to about 0.5% by weight of the emulsion, if any.

[0040] Method for defoaming industrial process streams

[0041] Generally, an antifoam composition according to an embodiment of the present invention can be used to defoam an industrial process stream in a method that comprises the step of adding to the industrial process stream an amount of the antifoam composition effective to defoam or prevent foaming in the industrial process stream, the antifoam composition comprising: an aqueous phase; and an organic phase emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long-chain fatty alcohol, the microcrystalline wax having a melting point of at least about 83 °C and at least one long-chain fatty alcohol having a carbon chain length of C 22 or longer and a melting point of at least about 62 °C.

[0042] The defoaming methods according to embodiments of the present invention can be practiced in any industrial process involving foaming, including process streams common in the processing or manufacturing of wood pulp, paper, textiles, cement, or paint, as well as processes for treating industrial wastewater, food processing, and oil drilling. These methods can actually be used in any industrial water system where foaming problems exist, but are particularly applicable to recirculating water systems, such as paper-making systems, cooling water systems (including cooling towers, open-loop and closed-loop cooling units), industrial raw water systems, drinking water distribution systems, disinfected drinking water systems, oil production or recovery systems (oilfield water systems, drilling fluids), fuel storage systems, metal processing systems, heat exchangers, reactors, equipment for storing and treating liquids, boilers and related steam generation units, radiators, flash units, refrigeration units, reverse osmosis equipment, gas scrubbing units, blast furnaces, sugar evaporation units, steam power plants, geothermal units, nuclear cooling units, water treatment units, pond recirculation units, mining circuits, closed-loop heating units, process fluids for operations such as drilling, boring, milling, reaming, drawing, broaching, turning, cutting, sewing, grinding, thread cutting, planing, spinning, and rolling, hydraulic oils, coolants, and the like. In some embodiments, the industrial process stream is an industrial process stream in a cement preparation process or a paint preparation process.

[0043] In one embodiment, the defoamer composition and / or emulsion disclosed herein is added or metered into the pulp and / or paper-making processing system. The composition can generally be used throughout the system to minimize and prevent foaming. In certain instances, the composition is added to the short loop of the system. Other examples of suitable addition points are large water storage towers for process water (recirculating water towers, filtrate water towers), clear or turbid filtrate storage tanks, pulpers or process streams upstream / downstream of the pulper, broke systems or process streams upstream / downstream of containers therein, cable pits or process streams upstream / downstream of the pits, paper machine mixing chests or process streams upstream / downstream of the chests, fresh water tanks, warm water tanks, and spray water tanks. Suitable addition points in a pulp mill system include digesters, thick stock streams, washers (such as thick stock washers), black liquor streams in the sulfate process or red liquor or brown liquor in the sulfite process. The composition can be fed continuously or periodically in batches. The composition can be replenished about 6 to about 24 times per day for about 3 to about 45 minutes each time, or for example, about 12 to about 24 times per day for about 10 to about 30 minutes each time.

[0044] Additional details regarding specific industrial processes are provided below for reference.

[0045] Paper-making process

[0046] In the paper industry, the sulfate process is a commonly used alkaline pulping process. In this process, waste chemicals can be recovered and reused, thereby reducing processing costs. A major drawback of this process is the formation of foam during the pulp screening and washing procedures.

[0047] The sulfate process (e.g., as taught in Liebling U.S. Patent No. 3,215,635) first cooks wood chips in a digester and then removes the waste chemicals for reuse. The resulting pulp fibers are then washed in a brown stock washer to remove a large amount of residual chemicals. These washers consist of a series of large vats (usually three or four in number) that alternately dilute the pulp with water and thicken it by picking up the pulp on a large rotating screen. The pulp is transported from the brown stock washer to a screening chamber (where it is again diluted with water) and passed through a vibrating screen, which now receives fully delignified fibers and rejects non-pulped fiber clumps, fiber knots, and other foreign matter. Since the diluted pulp is subject to vigorous agitation during screening, the foam problem in the screening chamber can be very severe. The water removed from the pulp after the screening operation is called diluted black liquor, and for economic reasons, it is usually used as the dilution water for the third and fourth stages of the brown stock washer. Diluted black liquor is a foaming material that contains, for example, about 0.001% to 0.1% solids by weight and has a pH of about 12. The foaming of diluted black liquor increases with an increase in the wood resin content used in this process.

[0048] Defoamers can be used in alkaline pulp mills during the screening operation in order to complete screening more effectively and prevent the pulp thickener used after the screening operation from being clogged by entrained air. When a water-dispersible defoamer is used during the screening operation, the control of foam and entrained air in the screening operation helps to improve the washing efficiency of the pulp during the alkaline pulping process. This is because the improved screening efficiency of the pulp makes it easier for the pulp to flow through the thickener and subsequent washers.

[0049] In paper recycling operations, the deinking detergents used to deink paper also cause severe defoaming problems. A detailed description of such processes can be found in standard textbooks such as A.M. Schwartz and J.W. Perry, SURFACE ACTIVE AGENTS, Volume I (1949); and SURFACE ACTIVE AGENTS AND DETERGENTS, Volume II (1958), Interscience Publishers, New York, the description of which is incorporated herein by reference.

[0050] A deinking agent is used in solution in a substantially aqueous medium in an amount ranging from about 0.3% to about 3% based on the paper weight. The temperature of the deinking solution can vary within any range from room temperature (including about 40°F to about 70°F (about 4°C to about 20°C)) to about 200°F (about 95°C). The process is generally carried out at an alkaline pH (i.e., from about 7.0 to about 11.5). Generally, the percentage of cellulose by weight in the deinking aqueous solution should be less than 10%, and preferably less than 6.0%, or between about 4.0% and 6.0%.

[0051] After the deinking treatment, the defibered material is poured into a tank or other reservoir and then diluted with water to a solids content between about 0.5% and about 1.5% (including about 1.0%) (based on the solution weight). After dilution, the pulp is separated from the solution and washed and thickened by known methods. Optionally, the pulp is then acidified to a pH between about 4 and about 6.5 (including about 4.5 to about 5.5), thickened and then formed into a web. The recovered pulp can be mixed with fresh virgin sulfate or sulfite pulp, or with additional recovered pulp, to manufacture cellulose products such as newspapers and the like. An antifoaming agent can be added during any of the above stages to control or prevent foam formation.

[0052] Cement preparation process

[0053] Reliably managing antifoaming chemicals is also a key step in cement production applications to prevent excessive foaming due to entrained air and avoid operational difficulties. Most of the chemical additives required for preparing cement slurries are surface-active molecules with an amphiphilic structure; on the one hand, they are soluble in the aqueous phase, and on the other hand, they are insoluble in the aqueous phase (or have limited solubility). This surface activity is responsible for stabilizing the gas-liquid interface and preventing excessive foam and air generation. Such additives include cement retarders, dispersants, filtration control additives, gas migration control agents, and ductility improvement additives. Chemicals used to enhance cement grinding are also considered to cause a certain degree of foaming.

[0054] The sources of air in the cement slurry include the air already contained in the system and the air entrained during mixing. This is a complex process affected by various factors such as the mixing method, the physical and chemical properties of the well cement, the water ratio and quality, the dosage and properties of the foaming agent, other chemical additives and supplementary cementitious materials (SCM), and a series of other parameters. The antifoaming agents of the present invention can be added at any time during the cement preparation sequence. They can be added to water or cement powder before the water and powder are mixed, or they can be added to the wet cement after the water and powder are mixed.

[0055] Textile preparation process

[0056] Defoamers are also employed during the scouring, desizing, bleaching, and dyeing operations of textile wet processing. In textile processing, scouring, desizing, and bleaching operations are used to remove foreign substances on the fabric, such as warp sizing, processing oils, dirt, and natural waxes, and detergents that typically generate foam are commonly used. These operations are carried out prior to dyeing to ensure that the prepared substrate will uniformly accept the dye.

[0057] Conventional defoamers can redeposit insoluble materials on the fabric during processing. If these insoluble materials are not removed prior to dyeing, they can form resist spots in the fabric where the dye cannot penetrate or, in the case of some synthetic fibers, oil spots where the fabric will actually be dyed darker at that spot. The defoamers of the present invention do not have this problem. They defoam during the higher temperature portion of the process employing a foaming surfactant and are then rinsed off at a lower temperature in a subsequent stage of the process.

[0058] Textile dyeing processes also employ foaming surfactants as wetting agents and post-scouring aids to remove loose dye substances. During the dyeing process, materials that will not redeposit on the fabric must be used to control foam. The defoamer compositions disclosed herein can also be applied during the dyeing process, where the actual dyeing will be carried out at a higher temperature using the disclosed defoamer, and then the article will subsequently be rinsed clean at a lower temperature.

[0059] The defoamer compositions according to embodiments of the present invention can be added to an industrial process stream and act as a defoamer when the industrial process stream is at a temperature of at least 75 °C, or at least 85 °C or at least 90 °C, or at a temperature of 75 °C to 95 °C or at a temperature of 85 °C to 95 °C.

[0060] Examples

[0061] The present invention will be further illustrated by the following examples, but these examples should not in any way be construed as limiting its scope. In contrast, it should be clearly understood that various other aspects, embodiments, modifications, and their equivalents can be resorted to without departing from the spirit of the present invention or the scope of the appended claims, and such embodiments, aspects, modifications, and their equivalents are implied to those of ordinary skill in the art after reading the description herein. Therefore, other aspects of the present invention will be clear to those of skill in the art in view of the specification and practice of the present invention disclosed herein. Example 1 – High Temperature Water-Based Defoamer Composition According to an Embodiment of the Present Invention

[0062] In this example, the defoamer composition according to an embodiment of the present invention is prepared in the form of an aqueous emulsion according to the formulation in Table A below. The amounts of the components are shown in parts by weight. The process for preparing the defoamer composition is as follows: (A) Add hot water, long-chain fatty alcohol, microcrystalline wax, biological wax, emulsifier, and salt to a reactor, and heat the reactor with stirring to 90°C to 98°C; (B) When all solids are melted under stirring at 90°C to 98°C, add fortified rosin and emulsifier to the reactor and mix for 0.5 to 1.0 hour; (C) Add an anionic surfactant to the reactor and stir at 90°C to 98°C for 2 to 10 minutes; (D) Immediately homogenize the emulsion solution from (C) at 6500 to 8500 rpm for 30 to 90 seconds; (E) Add a thickening agent to the homogenized emulsion solution from (D) and stir for 2 to 8 minutes; (F) Then add cold water, and rapidly cool the emulsion solution under stirring through ice water for 10 to 20 minutes; (G) Finally, add sodium nitrite, an antimicrobial agent, and stir for 0.5 to 1 hour.

[0063] Table A. Formulation of the defoamer composition in Example 1

[0064]

[0065]

[0066] Foam elimination and inhibition performance test

[0067] The foam elimination and inhibition performance of the defoamer composition in the example of Example 1 and a comparative defoamer composition (comparative example) were tested using the following method. The comparative defoamer composition is commercially available and sourced from Kemira Oyj in Helsinki, Finland, and includes: Kemira FT1950 (water-based defoamer, Comparative Example 1), FT4869 (oil-based defoamer, Comparative Example 2), FT6016 (silicone emulsion defoamer, Comparative Example 3), and FT6006 (silicone emulsion defoamer, Comparative Example 4).

[0068] A foam and entrained air test (FEAT) was conducted to test the defoaming performance of the example of Example 1 and the comparative examples, and the results are shown in Figures 1 to 5 . The FEAT method records the relationship between density and time, and these defoamer compositions were tested at 75°C and 85°C using a foaming medium of synthetic white water - 2% black liquor (pH = 5.70) from IP Savanna, GA at 40% power.

[0069] The FEAT test uses a test device that is used to determine the efficacy of defoamer compositions in a laboratory environment. The device measures the change in filtrate density over time after the introduction of the defoamer composition. The measure of the change in filtrate density is a direct measurement of the change in entrained air. For example, in a pulp and paper mill, the presence of entrained air can interfere with paper formation and drainage.

[0070] The experimental setup includes a water bath, temperature control, a foam column, a micropump, a densitometer, a computer, and acquisition software. The testing of samples utilizes a recirculating foam column connected to a pump. A hose leading from the pump is connected to the densitometer, which in turn returns and connects to the top of the foam column. A foaming medium is added to the test unit and pumped through the unit to fill the pipeline. Once the pump is started and the density drops due to air entrainment, the defoamer composition is added. The test runs for a predetermined time, and a sufficient number of data points are collected through the data acquisition software. A line graph is generated to show the change in liquid density over that time period. Then the area under the curve for each test is calculated. Those samples with the highest area under the curve measurements are the ones with the best performance.

[0071] For Example 1 and the comparative examples, white water is used as the foaming medium. Figure 1 and Figure 2 The results shown were obtained by heating 400 ml of the foaming medium to 75 °C and circulating the heated foaming medium. As the foaming medium circulates, the density of the medium drops due to foam formation.

[0072] At 75 °C, the defoamer composition of Example 1 showed improved efficacy compared to the defoamer composition of the comparative example.

[0073] When the medium density reaches the required minimum point, 15 μL of each defoamer composition is added to the defoaming medium. As Figure 1 shown, for the defoamer composition of Example 1, the density (i.e., the rapid defoaming phase) rapidly increases to a maximum density of approximately 0.992 g / cm3 in about 50 seconds. Thereafter, the density gradually decreases. The performance measured by the area under the curve (AUC) as shown in Figure 2 confirms these findings, where the defoamer composition of Example 1 showed the highest performance at 30 seconds and 3 minutes compared to the defoamer composition of the comparative example.

[0074] Similarly, at 85 °C, the defoamer composition of Example 1 showed improved efficacy compared to the defoamer composition of the comparative example.

[0075] Use the same process as Figure 1 and Figure 2 to obtain Figure 3 、 Figure 4 and Figure 5The data shown is different in that the defoamer performance is tested at 85 °C, and 15 μL of each defoamer composition is added to one group and 25 μL of each defoamer composition is added to another group. As Figure 3 shown, for the defoamer composition of Example 1, after adding 15 μL of each defoamer composition, the density (i.e., the rapid defoaming stage) rapidly increased to a maximum density of approximately 0.992 g / cm3 within about 50 seconds; and for the defoamer composition of Example 1, after adding 25 μL of each defoamer composition, the density (i.e., the rapid defoaming stage) rapidly increased to a maximum density of approximately 0.984 g / cm3 within about 50 seconds. Thereafter, the density gradually decreased. As measured by the area under the curve (AUC) shown by Figure 4 and Figure 5 the performance confirmed these findings, where the defoamer composition of Example 1 showed comparable or better performance after 30 seconds and 3 minutes compared to the defoamer composition of the comparative example. In addition, Figure 5 shows the performance relative to the defoamer compositions fed at 15 μL and 25 μL.

[0076] Stability performance test

[0077] The following method was used to test the stability of the defoamer compositions in the examples of Example 1 and the comparative examples.

[0078] An NDJ-8 viscometer was used and the test was carried out under the conditions of a #2 rotor and 6 rpm. In this test mode, the measurement range was 0 to 5000 mPa·s. After storage at 5 °C, room temperature (about 25 °C) and 40 °C for up to about 70 days, the viscosity change of the emulsion was measured. The test results are shown in Figure 6 and it can be seen that the emulsion prepared by the method according to Example 1 has excellent storage stability.

[0079] Examples

[0080] Examples of the present invention include but are not limited to the following:

[0081] Example 1. A defoamer composition comprising:

[0082] An aqueous phase; and

[0083] An organic phase, the organic phase being emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long-chain fatty alcohol, the melting point of the microcrystalline wax being at least about 83 °C, and the carbon chain length of the at least one long-chain fatty alcohol being C 22 or longer and the melting point being at least about 62 °C.

[0084] Example 2. The defoamer composition according to Example 1, wherein the carbon chain length of the at least one long-chain fatty alcohol is C22 to C 28 。

[0085] Example 3. The defoaming agent composition according to Example 1, wherein the carbon chain length of at least 80% by weight of the at least one long-chain fatty alcohol is C 22 to C 28 。

[0086] Example 4. The defoaming agent composition according to Example 1, wherein the melting point of the at least one long-chain fatty alcohol is from about 62 °C to about 67 °C.

[0087] Example 5. The defoaming agent composition according to any one of the foregoing examples, wherein the at least one long-chain fatty alcohol is present in the defoaming agent composition in an amount of from about 8% to about 30% by weight based on the weight of the defoaming agent composition.

[0088] Example 6. The defoaming agent composition according to any one of the foregoing examples, wherein the at least one long-chain fatty alcohol is present in the defoaming agent composition in an amount of from about 10% to about 20% by weight based on the weight of the defoaming agent composition.

[0089] Example 7. The defoaming agent composition according to any one of the foregoing examples, wherein the melting point of the microcrystalline wax is at least about 90 °C.

[0090] Example 8. The defoaming agent composition according to any of Examples 1 to 6, wherein the melting point of the microcrystalline wax is from about 83 °C to about 99 °C, or from about 85 °C to about 99 °C, or from about 90 °C to about 99 °C.

[0091] Example 9. The defoaming agent composition according to any one of the foregoing examples, wherein the at least one microcrystalline wax is present in the defoaming agent composition in an amount of from about 5% to about 25% by weight based on the weight of the defoaming agent composition.

[0092] Example 10. The defoaming agent composition according to any one of the foregoing examples, wherein the at least one microcrystalline wax is present in the defoaming agent composition in an amount of from about 6% to about 15% by weight based on the weight of the defoaming agent composition.

[0093] Example 11. The defoaming agent composition according to any one of the foregoing examples, which further comprises at least one emulsifier.

[0094] Example 12. The defoaming agent composition according to any one of the foregoing examples, which further comprises at least one surfactant.

[0095] Example 13. The defoaming agent composition according to any one of the foregoing examples, wherein the bioenergy content of the defoaming agent composition is at least 50% or at least 60%.

[0096] Example 14. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition functions as a defoaming agent at a temperature of at least 75°C.

[0097] Example 15. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition functions as a defoaming agent at a temperature of 75°C to 95°C.

[0098] Example 16. The defoaming agent composition according to any one of the preceding examples, wherein when the defoaming agent composition is stored at a temperature of about 40°C for up to 100 days, the defoaming agent exhibits a viscosity < 1500 cP; or when it is stored at a temperature of about 23°C for up to 100 days, it exhibits a viscosity < 900 cP; or when it is stored at a temperature of about 5°C for up to 100 days, it exhibits a viscosity < 800 cP.

[0099] Example 17. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition does not contain oil.

[0100] Example 18. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition does not contain silicone oil.

[0101] Example 19. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition does not contain silica.

[0102] Example 20. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition does not contain ethylene bisstearamide.

[0103] Example 21. The defoaming agent composition according to any one of the preceding examples, wherein the defoaming agent composition does not contain oil, silicone oil, silica or ethylene bisstearamide.

[0104] Example 22. A method for defoaming in an industrial process stream, the method comprising the step of adding to the industrial process stream an amount of a defoaming agent composition effective to defoam or prevent foaming in the industrial process stream, the defoaming agent composition comprising:

[0105] An aqueous phase; and

[0106] An organic phase, the organic phase being emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long-chain fatty alcohol, the melting point of the microcrystalline wax being at least about 83°C, and the carbon chain length of the at least one long-chain fatty alcohol being C22 or longer and the melting point being at least about 62°C.

[0107] Example 23. The method according to Example 22, wherein when the antifoaming agent composition is added to the industrial process stream, the temperature of the industrial process stream is at least 75 °C.

[0108] Example 24. The method according to Example 22, wherein when the antifoaming agent composition is added to the industrial process stream, the temperature of the industrial process stream is from 75 °C to 95 °C.

[0109] Example 25. A method for preparing an amount of an antifoaming agent composition effective to defoam or prevent foaming in an industrial process stream, the method comprising the steps of:

[0110] heating a mixture comprising water, at least one microcrystalline wax, and at least one long-chain fatty alcohol sufficiently to liquefy any solids, the microcrystalline wax having a melting point of at least about 83 °C, and the at least one long-chain fatty alcohol having a carbon chain length of C22 or longer and a melting point of at least about 62 °C;

[0111] adding at least one emulsifier and at least one surfactant to the mixture; and

[0112] homogenizing the mixture to form an emulsion comprising an organic phase emulsified into an aqueous phase.

[0113] Example 26. The method according to Example 25, wherein the surfactant is an anionic surfactant.

[0114] Example 27. The method according to Example 25, further comprising adding fortified rosin to the mixture prior to the homogenizing step.

[0115] Example 28. The method according to Example 25, comprising adding a thickening agent to the emulsion.

[0116] Example 29. The method according to Example 25, further comprising adding an antimicrobial agent to the emulsion.

[0117] Example 30. The method according to Example 25, wherein the industrial process stream is a thick stock stream or a black liquor stream in a pulp washing process.

[0118] All cited disclosures are incorporated herein by reference in their entirety. Additionally, in the event that the definition or use of a term in a reference incorporated by reference is inconsistent with or contrary to the definition of that term provided herein, the definition of the term provided herein shall apply and the definition of the term in the reference shall not apply.

[0119] Although specific aspects of conventional techniques have been discussed to facilitate the disclosure of various embodiments, the applicant does not in any way disclaim such technical aspects, and it is contemplated that the present disclosure may cover one or more of such conventional technical aspects discussed herein.

[0120] The present disclosure may address one or more problems and deficiencies of known methods and processes. However, it is contemplated that various embodiments may prove useful for addressing other problems and deficiencies in several technical fields. Accordingly, the present disclosure should not necessarily be construed as limited to addressing any specific problem or deficiency discussed herein.

[0121] In this specification, when referring to or discussing a document, act, or item of knowledge, such reference or discussion does not admit that the document, act, or item of knowledge or any combination thereof was publicly available, known to the public, part of common general knowledge, or otherwise constituted prior art as of the priority date; or known in connection with an attempt to solve any problem addressed in this specification.

[0122] In the descriptions provided herein, the terms "comprising", "is", "including", "having", and "containing" are used in an open-ended manner and should thus be construed to mean "including but not limited to". Unless otherwise specified, when a composition, system, or method is claimed or described as "comprising" various steps or components, such composition, system, or method may also "consist essentially of" the various steps or components or "consist of" the various steps or components.

[0123] The terms "a", "an", and "the" are intended to include plural alternatives, e.g., at least one. For example, unless otherwise specified, the disclosure of "a first monomer", "a polymer composition", etc. is intended to cover a mixture or combination of one or more than one first monomer, polymer composition, etc.

[0124] Various numerical ranges may be disclosed herein. When the applicant discloses or claims any type of range, the applicant's intention is to separately disclose or claim each possible number that the range can reasonably cover, including the endpoints of the range and any sub-ranges and combinations of sub-ranges covered, unless otherwise specified. Additionally, all numerical endpoints of the ranges disclosed herein are approximate. As a representative example, the applicant discloses in some embodiments that an antifoaming agent composition is effective at a temperature of from 85°C to 95°C. This range should be understood to cover temperatures of from about 85°C to about 95°C and further to cover each of "about" 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, and 94°C (including any ranges and sub-ranges between any of these values).

[0125] As used herein, the term "about" means ±10% of the numerical value of the number being used.

Claims

1. An antifoaming agent composition, comprising: An aqueous phase; and An organic phase, which is emulsified in the aqueous phase and contains at least one microcrystalline wax and at least one long-chain fatty alcohol, the melting point of the microcrystalline wax being at least about 83 °C, and the carbon chain length of the at least one long-chain fatty alcohol being C 22 or longer and having a melting point of at least about 62 °C.

2. The defoaming agent composition according to claim 1, wherein the carbon chain length of the at least one long-chain fatty alcohol is C 22 to C 28 .

3. The defoaming agent composition according to claim 1, wherein at least 80% by weight of the at least one long-chain fatty alcohol has a carbon chain length of C 22 to C 28 .

4. The antifoaming agent composition according to claim 1, wherein the melting point of the at least one long-chain fatty alcohol is from about 62°C to about 67°C.

5. The antifoaming agent composition according to claim 1, wherein the at least one long-chain fatty alcohol is present in the antifoaming agent composition in an amount of from about 8% to about 30% by weight based on the weight of the antifoaming agent composition.

6. The antifoaming agent composition according to claim 1, wherein the at least one long-chain fatty alcohol is present in the antifoaming agent composition in an amount of from about 10% to about 20% by weight based on the weight of the antifoaming agent composition.

7. The antifoaming agent composition according to claim 1, wherein the melting point of the microcrystalline wax is at least about 90°C.

8. The antifoaming agent composition according to claim 1, wherein the melting point of the microcrystalline wax is from about 83°C to about 99°C, or from about 85°C to about 99°C, or from about 90°C to about 99°C.

9. The antifoaming agent composition according to claim 1, wherein the at least one microcrystalline wax is present in the antifoaming agent composition in an amount of from about 5% to about 25% by weight based on the weight of the antifoaming agent composition.

10. The antifoaming agent composition according to claim 1, wherein the at least one microcrystalline wax is present in the antifoaming agent composition in an amount of from about 6% to about 15% by weight based on the weight of the antifoaming agent composition.

11. The antifoaming agent composition according to claim 1, further comprising at least one emulsifier.

12. The antifoaming agent composition according to claim 1, further comprising at least one surfactant.

13. The antifoaming agent composition according to claim 1, wherein the bioenergy content of the antifoaming agent composition is at least 50% or at least 60%.

14. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition functions as an antifoaming agent at a temperature of at least 75°C.

15. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition functions as an antifoaming agent at a temperature of from 75°C to 95°C.

16. The antifoaming agent composition according to claim 1, wherein when the antifoaming agent composition is stored at a temperature of about 40°C for up to 100 days, the antifoaming agent exhibits a viscosity < 1500 cP; or when it is stored at a temperature of about 23°C for up to 100 days, it exhibits a viscosity < 900 cP; or when it is stored at a temperature of about 5°C for up to 100 days, it exhibits a viscosity < 800 cP.

17. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition is oil-free.

18. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition is silicone oil-free.

19. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition is silica-free.

20. The antifoaming agent composition according to claim 1, wherein the antifoaming agent composition is ethylene bis-stearamide-free.

21. The defoaming agent composition according to claim 1, wherein the defoaming agent composition does not contain oil, silicone oil, silica or ethylene bisstearamide.

22. A method for defoaming in an industrial process stream, the method comprising the step of adding to the industrial process stream an amount of a defoaming agent composition effective to defoam or prevent foaming in the industrial process stream, the defoaming agent composition comprising: an aqueous phase; and an organic phase, the organic phase being emulsified in the aqueous phase and comprising at least one microcrystalline wax and at least one long chain fatty alcohol, the microcrystalline wax having a melting point of at least about 83 °C, and the at least one long chain fatty alcohol having a carbon chain length of C22 or longer and a melting point of at least about 62 °C.

23. The method according to claim 22, wherein when the defoaming agent composition is added to the industrial process stream, the temperature of the industrial process stream is at least 75 °C.

24. The method according to claim 22, wherein when the defoaming agent composition is added to the industrial process stream, the temperature of the industrial process stream is from 75 °C to 95 °C.

25. A method for preparing an amount of a defoaming agent composition effective to defoam or prevent foaming in an industrial process stream, the method comprising the steps of: heating a mixture comprising water, at least one microcrystalline wax and at least one long chain fatty alcohol sufficiently to liquefy any solids, the microcrystalline wax having a melting point of at least about 83 °C, and the at least one long chain fatty alcohol having a carbon chain length of C22 or longer and a melting point of at least about 62 °C; adding to the mixture at least one emulsifier and at least one surfactant; and homogenizing the mixture to form an emulsion comprising an organic phase emulsified into an aqueous phase.

26. The method according to claim 25, wherein the surfactant is an anionic surfactant.

27. The method according to claim 25, further comprising adding fortified rosin to the mixture before the homogenizing step.

28. The method according to claim 25, further comprising adding a thickening agent to the emulsion.

29. The method according to claim 25, further comprising adding an antimicrobial agent to the emulsion.

30. The method according to claim 25, wherein the industrial process stream is a thick stock stream or a black liquor stream in a pulp washing process.

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