One pass deoxygenation process for producing polyacrylamide

Abstract

The invention relates to a method and an apparatus for degassing a monomer composition. In particular, the present disclosure provides a method and apparatus for deoxygenating a monomer solution during transfer from a monomer storage tank to a reactor. The degassing is carried out in one pass by combining a jet of nitrogen with a monomer solution in a Venturi injector (Venture Injector). The degassing method and apparatus of the present invention provide enhanced degassing performance.

Description

[0001] Related applications

[0002] This invention relates to and claims the benefit of priority to U.S. Provisional Application No. 63 / 513,517, filed July 13, 2023, and Finnish Application No. FI 20236045, filed September 21, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This invention relates to a method and apparatus for degassing monomer compositions. Specifically, this disclosure provides a method and apparatus for deoxygenating a monomer solution during transfer from a monomer storage tank to a reactor. Degassing is performed repeatedly by combining a jet of nitrogen with the monomer solution in a Venturi injector. Background Technology

[0004] Monomer degassing is a particularly important unit operation step in polymer manufacturing, especially for acrylamide polymers, namely emulsion polyacrylamide (EPAM) and dry polyacrylamide (DPAM), as well as other polymer products. The presence of dissolved oxygen (DO) tends to inhibit polymerization in the monomer solution, thus allowing the monomer solution to be prepared and pumped into the feed tank before being pumped into the polymerization reactor without undesirable polymerization. Typically, the monomer solution is transferred to the polymerization reactor and then degassed by various methods before polymerization begins.

[0005] In the first commonly used degassing option, the monomer mixture is degassed in a tilting reactor after being cooled; examples of this method have been implemented in existing polymer production plants. In tilting reactor applications, after the monomer solution is pumped into the reactor, N2 is injected through the pipe inlet into the bulk monomer solution for 40 to 60 minutes or longer. This allows for the achievement of target DO values ​​of ≤ 500 ppb (more preferably ≤ 200 ppb). These target DO values ​​must be achieved before polymerization begins.

[0006] The second degassing option consists of injecting and degassing the monomer solution using a bubble column. N2 is injected through the bubble column into the bulk monomer solution. Gas introduction occurs at the bottom of the column, inducing turbulence to enable gas exchange. This second method is used in several industrial applications, but it is not suitable for tilting reactors because they require higher flow rates compared to belt reactor technology.

[0007] Both the tilting reactor degassing option and the bubble column degassing option require large volumes of nitrogen and excessively long degassing times.

[0008] This invention addresses these limitations and needs by providing a novel and efficient method and apparatus for degassing monomer solutions using a Venturi ejector. The invention proposes a novel system and procedure for deoxygenating a monomer solution during transfer from a storage tank to a reactor. During the transfer from the monomer storage tank to the reactor, the monomer can be transferred after cooling and degassing.

[0009] The object of this invention is to provide a method and apparatus for degassing a monomer solution repeatedly via a Venturi ejector during transfer from a feed tank to a reactor. The method of this invention allows for repeated degassing by injecting pressurized nitrogen into the Venturi ejector. Summary of the Invention

[0010] This invention relates to a method and apparatus for degassing monomer compositions. Specifically, this disclosure provides a method and apparatus for deoxygenating a monomer solution during transfer from a monomer storage tank to a reactor. Degassing is performed repeatedly by combining a jet of nitrogen with the monomer solution in a Venturi injector. The method and apparatus of this invention provide more efficient degassing, allowing for increased monomer degassing capacity, reduced monomer degassing time, and reduced N2 consumption compared to conventional degassing methods.

[0011] On one hand, the present invention provides a method for degassing a monomer composition, the method comprising:

[0012] (a) Providing or generating a liquid monomer composition in a feed tank, wherein the monomer solution contains an initial dissolved oxygen (DO) content;

[0013] (b) Cooling the monomer solution to a temperature below 10°C, thereby forming a cooled monomer composition;

[0014] (c) Injecting a jet of N2 gas into the gas inlet of a Venturi injector at a certain N2 flow rate;

[0015] (d) The cooled monomer composition is pumped into the kinetic fluid inlet of the Venturi injector at a certain kinetic flow rate, and the jet of N2 gas is allowed to contact the cooled monomer composition, thereby forming a gas-liquid mixture;

[0016] (e) Pumping the gas-liquid mixture through a pipe of a certain length having an inner diameter (ID); and

[0017] (f) The gas-liquid mixture is pumped through a degasser and gas-liquid separation is allowed to occur, thereby forming a degassed monomer composition with a final DO content;

[0018] Steps (a)-(f) are performed consecutively.

[0019] In some exemplary embodiments, the method further includes

[0020] (a) Determining the initial DO content of the liquid monomer composition and / or the cooled monomer composition; and

[0021] (b) After step (f), determine the final DO content of the degassed monomer composition.

[0022] In some exemplary implementations of the method:

[0023] (a) The initial DO content ranges from 2-20 ppm, 4-18 ppm, 8-16 ppm, or 10-14 ppm; and / or

[0024] (b) The final DO content includes the required DO content in the range of < 500 ppb, 10-500 ppb, 50-450 ppb, 100-400 ppb or 200-300 ppb.

[0025] In some exemplary embodiments, the method further includes:

[0026] (a) Pumping the gas-liquid mixture through a static mixer located upstream of the pipeline of the specified length;

[0027] (b) Pumping the degassed monomer composition to a discharge tank or storage tank;

[0028] (c) The degassed monomer composition is pumped into a polymerization reactor, wherein a polymerization reaction is initiated;

[0029] (d) Optionally, after step (f), if the final DO content is greater than the desired DO content and / or if further degassing is required, the degassed monomer composition is recycled back into the feed tank and subjected to a second degassing pass, the second degassing pass comprising repeating steps (b)-(g).

[0030] (e) Optionally, the degassed monomer composition is subjected to a third, fourth, and / or fifth degassed pass, wherein the third, fourth, and / or fifth degassed pass comprises subsequently recycling the degassed monomer composition back into the feed tank and repeating steps (b)-(g); or

[0031] Any combination of (f)(a)-(e).

[0032] In some exemplary implementations of the method:

[0033] (a) The feed tank includes a cooling component and a component for agitating the liquid monomer composition;

[0034] (b) The temperature is low enough to prevent polymerization of the liquid monomer composition, and the range is -5°C to 10°C; 0-10°C or 3-5°C;

[0035] (c) The power flow rate is controlled by a screw pump arranged in a line between the feed tank and the Venturi injector;

[0036] (d) The N2 flow rate is controlled by a gas flow meter and one or more pressure regulators, regulator valves and / or needle valves arranged in a line between the pressurized N2 source and the Venturi injector.

[0037] (e) When the gas-liquid mixture flows downstream of (i) the Venturi injector, (ii) between the Venturi injector and the degasser, or (iii) within the pipe of a certain length, the gas-liquid mixture contains a Reynolds number (Re) in the range of 2300-8000, 3000-8000, 4000-8000, or 4000-6000, and / or contains turbulence;

[0038] (g) The gas-liquid mixture comprises the cooled monomer composition and finely ground N2, the finely ground N2 comprising dissolved N2, atomized N2, micro N2 bubbles and / or macro N2 bubbles, wherein the finely ground N2 is small enough to allow gas-liquid mass transfer of DO, dissolved gas and / or volatile molecules from the cooled monomer composition to the finely ground N2, thereby allowing removal of the DO, the dissolved gas and / or the volatile molecules from the cooled monomer composition;

[0039] (h) The pipe of a certain length provides residence time for the gas-liquid mixture between the Venturi injector and the degasser, and optionally includes a coiled pipe.

[0040] (i) The degasser includes a hydraulic separator and an exhaust port; or

[0041] Any combination of (j)(a)-(h).

[0042] In some exemplary embodiments of the method, one or more of the following are adjusted to achieve the desired final DO content:

[0043] (a) The Reynolds number characterizing the gas-liquid mixture;

[0044] (b) The N2 flow rate;

[0045] (c) the dynamic flow velocity;

[0046] (d) The inner diameter (ID) of the pipe of a certain length;

[0047] (e) The length (L) of the pipe of a certain length; or

[0048] Any combination of (f)(a)-(e).

[0049] In some exemplary embodiments of the method, the liquid monomer composition comprises:

[0050] (a) An aqueous monomer solution comprising water and at least one monomer, wherein the at least one monomer comprises one or more nonionic monomers, one or more anionic monomers, one or more cationic monomers, or any combination thereof; wherein

[0051] (i) The one or more nonionic monomers are selected from the group consisting of monomers containing primary amides, including acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and any combination thereof;

[0052] (ii) The one or more cationic monomers are selected from: acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate di ... Methyl methacrylate sulfate quaternary salt, dimethyl methacrylate benzyl chloride quaternary salt, dimethyl methacrylate sulfate, dimethyl methacrylate hydrochloride, methacryloyl dimethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkylammonium halides, including but not limited to diallyl diethylammonium chloride and diallyl dimethylammonium chloride (“DADMAC”), and any combination thereof; and

[0053] (iii) The one or more anionic monomers contain functional groups selected from the following: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamido-tert-butylsulfonic acid (ATBS), acrylamido-methanesulfonic acid, acrylamido-ethanesulfonic acid, 2-hydroxy-3-acrylamido-propanesulfonic acid, styrene sulfonic acid, and vinyl phosphonic acid, their corresponding alkali metals, alkaline earth metals, and ammonium salts, and any combination thereof;

[0054] (b) comprising 1-70% by weight, 5-50% by weight, 25-45% by weight, or 30-40% by weight of at least one of the monomers; or

[0055] Any combination of (c)(a)-(c).

[0056] In some exemplary implementations of the method:

[0057] (a) The liquid monomer composition comprises acrylamide, acrylic acid, acrylamide tert-butylsulfonic acid (ATBS), or any combination thereof; or

[0058] (b) The degassed monomer composition is used to produce dry polyacrylamide (DPAM) or emulsion polyacrylamide (EPAM).

[0059] In some exemplary implementations of the method:

[0060] (a) The method results in the degassed monomer composition having the desired final DO content after a first degassed cycle, wherein the first degassed cycle comprises a single application of steps (a)-(f) according to claim 1; and / or

[0061] (b) The method results in (i) increased monomer degassing capacity, (ii) reduced monomer degassing time, (iii) reduced N2 consumption, or (iv) any combination of (i)-(iii) compared to conventional methods for degassing monomer compositions, wherein the conventional methods involve injecting N2 gas through a pipeline or bubble column to the bulk monomer composition in a reactor or storage tank.

[0062] On the other hand, the present invention provides a degassed monomer composition that can be obtained by the method according to any one of claims 1 to 9, wherein the degassed monomer composition contains a desired final DO content in the range of < 500 ppb, 10-500 ppb, 50-450 ppb, 100-400 ppb, or 200-300 ppb.

[0063] On the other hand, the present invention provides an apparatus for degassing a monomer composition, the apparatus comprising:

[0064] (a) A monomer feed tank, the monomer feed tank comprising a cooling component and a component for stirring the liquid monomer composition;

[0065] (b) A component, piping, and Venturi ejector for controlling the kinetic flow rate of the liquid monomer composition, the Venturi ejector comprising a kinetic fluid inlet, a gas inlet, and an outlet, wherein the component for controlling the kinetic flow rate and the piping are arranged in a line between the monomer feed tank and the kinetic fluid inlet on the Venturi ejector.

[0066] (c) A pressurized N2 source and components for controlling the N2 flow rate, said components being arranged in line with the gas inlet on the Venturi injector; and

[0067] (d) A pipe of a certain length having an inner diameter (ID) and a degasser, wherein the pipe of a certain length is arranged in a line between the outlet of the Venturi injector and the degasser.

[0068] In some exemplary embodiments, the device further includes:

[0069] (a) a dissolved oxygen (DO) meter, said DO meter being arranged in contact with the liquid monomer composition and located upstream of the Venturi injector; and / or

[0070] (b) A second dissolved oxygen (DO) meter, which is arranged to contact the degassed liquid monomer composition and is located downstream of the degasser.

[0071] In some exemplary embodiments, the device further includes

[0072] (a) A gas-liquid mixing component, optionally a static mixer, said component being arranged downstream of the degasser;

[0073] (b) A discharge tank, storage tank or polymerization reactor located downstream of the degasser;

[0074] (c) A component that allows N2 to flow into the discharge tank, the storage tank, or the polymerization reactor;

[0075] (d) Optionally, the degassed liquid monomer composition is recirculated to the monomer feed tank or directly to a component in the kinetic fluid inlet of the Venturi injector; or

[0076] The combination of (e)(a) and (c).

[0077] In some exemplary embodiments of the device:

[0078] (a) The cooling component includes a cooling coil, and the stirring component includes a stirrer;

[0079] (b) The components for controlling the dynamic flow rate include a screw pump and a single-unit flow meter;

[0080] (c) The component for controlling the N2 flow rate includes a gas flow meter and one or more N2 pressure regulators, one or more N2 regulator valves and / or one or more N2 needle valves arranged in a line between the pressurized N2 source and the gas inlet on the Venturi injector.

[0081] (d) The pipe of a certain length includes straight pipes or conduits, coiled pipes or conduits, or combinations thereof;

[0082] (e) The degasser includes a hydraulic separator and an exhaust port; or

[0083] Any combination of (f)(a)-(e).

[0084] In some exemplary embodiments, the device further includes:

[0085] (a) One or more pressure sensors, one or more flow meters, one or more rotor flow meters;

[0086] (b) A feed tank discharge valve, wherein the feed tank discharge valve is arranged in a line between the individual feed tank and the screw pump;

[0087] (c) A hydraulic separator discharge valve, which is located downstream of the degasser. Attached Figure Description

[0088] The present invention will now be described in more detail with reference to the accompanying drawings.

[0089] Figure 1 An exemplary piping and instrumentation diagram (PID) with numbering is provided for the degassing test unit according to Embodiment 1.

[0090] Figure 2 An exemplary rendering of the degassing test unit according to Embodiment 1 is provided.

[0091] Figure 3 An exemplary rendering of the pilot plant layout of the degassing test unit according to Embodiment 1 is provided.

[0092] Figure 4 An exemplary image is provided showing the layout of a pilot plant for a degassing test unit constructed in Aberdeen, USA, according to Embodiment 1.

[0093] Figure 5 A second exemplary image is provided showing the layout of a pilot plant for a degassing test unit built in Aberdeen, USA, according to Embodiment 1.

[0094] Figure 6 A third exemplary image is provided showing the layout of a pilot plant for a degassing test unit built in Aberdeen, USA, according to Embodiment 1.

[0095] Figure 7 A fourth exemplary image is provided showing the layout of a pilot plant for a degassing test unit built in Aberdeen, USA, according to Embodiment 1.

[0096] Figure 8An exemplary graph is provided showing the modeling results of dissolved oxygen (DO) relative to pipeline length according to Example 2.

[0097] Figure 9 An exemplary graph summarizing the statistical effects of DO content based on the main parameters of Example 4 is provided.

[0098] Figure 10 An exemplary dissolved oxygen (DO) prediction graph is provided, illustrating the relationship between actual DO and predicted DO according to Example 4.

[0099] Figure 11 An exemplary graph of statistical curves is provided, illustrating the effect of key parameters on DO content and degassing time according to Example 4. Detailed Implementation

[0100] Before describing the present invention, the following definitions are provided. Unless otherwise stated, all terms should be interpreted in accordance with the understanding of those skilled in the art.

[0101] definition

[0102] Unless otherwise expressly stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0103] As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural references. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” may mean “a,” but also include plural references such as “one or more” and “at least one.”

[0104] As used herein, the term “or” in the claims is used to mean “and / or” unless it is explicitly stated that it refers only to alternatives or that alternatives are mutually exclusive, but this disclosure supports the definition of “and / or” as referring only to alternatives.

[0105] As used in this article, the term “about” means ± 10% of the value of the number being used.

[0106] As used herein, unless otherwise stated, the term "or combinations thereof" as used herein refers to all permutations and combinations of the items listed preceding the term.

[0107] Processes and equipment

[0108] The term “in a line” refers to any component or equipment in an industrial setup that is connected to other components or equipment via a pipe, conduit, or any conduit, through which an industrial process flow (e.g., a monomer solution) may flow, for example, by pumping.

[0109] As used herein, the terms “upstream” and “downstream” refer to the relative orientation of components, equipment, or materials within an industrial process or apparatus through which fluid or liquid materials can flow, for example, by pumping. The pumped fluid encounters the upstream location before encountering the downstream location.

[0110] As used herein, the term "one pass" or "first pass" refers to subjecting a monomer solution to a single application of degassing using the apparatus of the present invention.

[0111] As used herein, the term “residence time” refers to the contact time between nitrogen gas before degassing and the industrial process stream (e.g., monomer solution).

[0112] As used herein, the term "Reynolds number" or "Re" is a dimensionless quantity in fluid mechanics that, by measuring the ratio between inertial forces and viscous forces, helps predict the flow patterns of fluids and fluid-gas mixtures under different conditions. For the purposes of this invention, the Reynolds number (Re) refers to the gas-liquid mixture formed when pressurized N2 gas is forced into a liquid monomer through the gas inlet of a Venturi ejector, thereby mixing with the kinetic fluid of the liquid monomer pumped to the kinetic fluid inlet of the Venturi ejector. When the N2 gas contacts the liquid monomer, a gas-liquid mixture is formed, which is pumped downstream of the Venturi ejector, optionally through a static mixer, and further optionally through a length of pipe, and into a degasser. At low Reynolds numbers, the flow of the gas-liquid mixture tends to be predominantly laminar (sheet-like), while at high Reynolds numbers, turbulence dominates. The Reynolds number of the flowing gas-liquid mixture can be calculated using any of several methods known in the art. Laminar flow occurs when the calculated Reynolds number is less than 2300. A Reynolds number exceeding 4000 indicates turbulence. When the flow occurs between laminar and turbulent conditions (Re 2300 to Re 4000), the flow condition is called critical. Critical flow is neither perfectly laminar nor perfectly turbulent, but a combination of both.

[0113] As used herein, the term "dynamic flow rate" refers to the flow rate of liquid entering the dynamic fluid inlet of a Venturi ejector.

[0114] As used herein, the term "Venturi injector" refers to an eductor adapted to accept a pressurized N2 stream. The term "ejector" generally refers to a device used to mix gas and liquid. When pressurized water enters the injector inlet, it contracts toward the ejection chamber and becomes a high-speed jet. Typically, the increased velocity through the contraction causes a decrease in absolute pressure, creating a vacuum that draws in liquid or gaseous additives (e.g., N2) through the suction port and thoroughly mixes them into the kinetic fluid stream. In other words, as the fluid passes through the small diameter (constriction) of the venturi, the pressure decreases, creating a vacuum based on Bernoulli's law. As the jet diffuses toward the injector outlet, its velocity decreases, and it resumes flow in a fully mixed state, with slightly less energy than when it entered the injector.

[0115] In this invention, a pressurized N2 gas stream is injected or forced into the liquid monomer kinetic fluid stream through a gas inlet passing through a Venturi injector (i.e., an eductor), thereby providing a higher N2 flow rate into the liquid stream and a more turbulent gas-liquid mixture achievable under a vacuum created by the Bernoulli effect. This results in turbulence in the N2 gas-liquid mixture when pumped between the Venturi injector and the degasser. In some exemplary embodiments, when flowing (i) downstream of the Venturi injector, (ii) between the Venturi injector and the degasser, or (iii) within the length of the conduit, the Reynolds number (Re) of the N2 gas-liquid mixture is greater than 2300, greater than 4000, greater than 5000, or greater than 6000 for at least a portion of the distance between the Venturi injector and the degasser. In other embodiments, the Reynolds number (Re) of the N2 gas-liquid mixture is greater than 4000, greater than 5000, or greater than 6000 for at least part or all of the distance between the Venturi injector and the degasser. A Reynolds number greater than 4000 for the flowing gas / liquid mixture indicates turbulence.

[0116] In some embodiments, other forms of ejectors can be used directly or are adapted for use as devices for mixing pressurized or compressed N2 gas into a liquid polymer kinetic fluid. In some embodiments, other forms of ejectors include hootenanny or liquid jet pumps, a simple type of pump that utilizes the Venturi effect to pump or move fluids (air, liquid, or gas) in a closed line.

[0117] Industrial process flow

[0118] As used herein, the term "process flow" or "industrial process flow" generally refers to any aqueous fluid, solution, slurry, or dispersion generated during any type of industrial process, such as those associated with chemical manufacturing, polymer manufacturing, pulp and paper industries, oil or gas extraction or recovery (including recovery, extraction, refining, or waste treatment), waste treatment, water treatment, painting and coating, food and beverage processing, mining, textiles, agriculture, or any part thereof. Exemplary embodiments of a process flow include an aqueous monomer solution to be degassed and polymerized. The methods and apparatus of the present invention for degassing can be applied to any process flow requiring degassing of aqueous solutions or process flows.

[0119] As used herein, the term "aqueous solution" or "solution" refers to a mixture of water and one or more water-soluble solutes, which are completely dissolved with little or no undissolved solute residue (e.g., monomer). The solution may be homogeneous.

[0120] As used herein, the term "emulsion" refers to a multiphase fluid system in which droplets are dispersed in another immiscible liquid. An emulsion is a mixture of two or more normally immiscible (immiscible or non-mixable) liquids, exhibiting liquid-liquid phase separation. An emulsion comprises two phases, a "dispersed / internal phase" and a "continuous / external phase," which are liquids. In an emulsion, one liquid (dispersed phase) is suspended or dispersed as individual droplets throughout another liquid (continuous phase). The typical main components of an emulsion are two liquid phases (typically oil and water) and an emulsifier that stabilizes the interface between the two liquid phases. Emulsifiers can be various molecules, such as polymers, amphiphilic surfactants, and proteins, and can also be colloidal particles.

[0121] polymer

[0122] As used herein, the terms “polymer” or “polymer additive” and similar terms are used in their ordinary meaning as understood by those skilled in the art, and are therefore used herein to refer to or describe macromolecules (or groups of such molecules) that may contain repeating units. Polymers can be formed in a variety of ways, including by polymerizing monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise stated, polymers may comprise “homopolymers” that may contain substantially the same repeating units, which can be formed, for example, by polymerizing a particular monomer. Unless otherwise stated, polymers may also comprise “copolymers” that may contain two or more different repeating units, which can be formed, for example, by copolymerizing two or more different monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise stated, polymers or copolymers may also comprise “terpolymers” or “quaternary copolymers,” which generally refer to polymers containing three, four, or more different repeating monomer units. As used herein, the term “polymer” is intended to include both the acidic form of the polymer and its various salts. Polymers can be inherently amphoteric, that is, containing both anionic and cationic substituents, but not necessarily in equal proportions.

[0123] As used herein, “emulsion polyacrylamide (EPAM)” means an emulsion polymer in which at least one polymer is an acrylamide-containing polymer. In some embodiments, based on the total amount of all components of the emulsion polyacrylamide (EPAM), the emulsion polyacrylamide (EPAM) contains a small amount of water, for example less than about 12% by weight, about 10% by weight, about 5% by weight, about 3% by weight, about 2.5% by weight, about 2% by weight, or about 1% by weight.

[0124] As used herein, "emulsion polymer" generally refers to a reverse emulsion (water-in-oil), in which water droplets containing the polymer are suspended in an oil phase (also known as a hydrophobic phase). In some embodiments, the emulsion polymer contains a small amount of water, such as less than about 12 wt%, about 10 wt%, about 5 wt%, about 3 wt%, about 2.5 wt%, about 2 wt%, or about 1 wt%, based on the total amount of all components of the emulsion polymer. The emulsion polymer is encapsulated in oil bubbles (droplets) called micelles. It is immobilized there by a surfactant. The surfactant makes the surface tension of the micelles greater than that of the surrounding water. If the water concentration increases or the micelles are broken by agitation, the polymer is released into the water and begins to polymerize. In some embodiments, EPAM may contain about 33% active polymer, 10% oil, and the remainder water and surfactant. In contrast, DPAM is 95% active, which enables more efficient transport and storage.

[0125] As used herein, "dry polymer" refers to a solid polymer in powder, granular, or combination thereof that is substantially free of or anhydrous. A non-limiting example is polyacrylamide powder or dry polyacrylamide (DPAM), which is a polymer or copolymer containing acrylamide.

[0126] As used herein, the term "polyacrylamide" or "PAM" generally refers to polymers and copolymers containing an acrylamide moiety, and the term covers any polymer or copolymer (including terpolymers) containing an acrylamide moiety, such as one or more acrylamide polymers (copolymers) and additional monomers capable of copolymerizing with acrylamide. Furthermore, PAM may include any of the polymers or copolymers discussed herein.

[0127] As used herein, the term "monomer" generally refers to nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, betaine monomers, and zwitterionic-pair monomers.

[0128] As used herein, the term "nonionic monomer" generally refers to a monomer having a neutral charge. Exemplary nonionic monomers may comprise, but are not limited to, monomers comprising the group consisting of: acrylamide ("AMD"), methacrylamide, vinyl, allyl, ethyl, etc., all of which may be substituted with side chains selected from, for example, alkyl, aralkyl, dialkyl, ethoxy, and / or hydrophobic groups. In one exemplary embodiment, the nonionic monomer may comprise AMD. In some embodiments, the nonionic monomer may comprise, but is not limited to, vinylamides (e.g., acrylamide, methacrylamide, N-methacrylamide, N,N-dimethylacrylamide), 4-acryloylmorpholine, maleic anhydride, N-vinylpyrrolidone, vinyl acetate, N-vinylformamide, and their derivatives, such as hydroxyethyl(meth(acrylate)CH2=CR-COO-CH2CH2OH (I) and CH2=CR-CO-N(Z1)(Z2) (2) N-substituted (meth)acrylamide (II), R = H or Me; Z1 = 5-15C alkyl; 1-3C alkyl substituted with 1-3 phenyl, phenyl, or 6-12C cycloalkyl (both optionally substituted), and Z2 = H; or Z1 and Z2 are each 3-10C alkyl; (II) is N-tert-hexyl, tert-octyl, methylundecyl, cyclohexyl, benzyl, diphenylmethyl, or triphenylacrylamide. Nonionic monomers include N-isopropylacrylamide, N-vinylformamide, methacrylamide; N-alkylacrylamide, including but not limited to N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, and N-butylacrylamide; N,N-dialkylacrylamide, including but not limited to N,N-dimethylacrylamide and N,N-diethylacrylamide; N-alkylmethylacrylamide; alkyl acrylates; hydroxyalkyl acrylates and hydroxyalkyl methacrylates, including but not limited to methyl acrylate, 2-hydroxy acrylate... Ethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate; dialkyl acrylates and dialkyl methacrylates, including but not limited to 2,3-dihydroxypropyl acrylate, 3,4-dihydroxybutyl acrylate, 2,3-dihydroxypropyl methacrylate (DHPMA), and 3,4-dihydroxybutyl methacrylate; alkyl acrylates, including but not limited to methyl methacrylate; acrylonitrile; N-vinylmethylacetamide, N-vinylmethylformamide; N-vinyl acetate, glyoxylated acrylamide, and vinylpyrrolidone. For example, nonionic monomers can be combined with acrylamide to form copolymers.

[0129] As used herein, the term "anionic monomer" can refer to an anionic monomer that is substantially all or part (in equilibrium) anionic in a pH range of about 1.0 to about 10.0. Depending on the pKa value of the acidic protons contained therein, anionic monomers may be neutral at low pH levels (e.g., about 0-1, 0-2, or 0-3). Some anionic monomers are obtained in anionic form, such as alkali metal salts, alkaline earth metal salts, and ammonium salts, such as acrylic acid and sodium acrylamide tert-butyl sulfonate (ATBS).

[0130] Examples of anionic monomers that may be used herein include, but are not limited to, anionic monomers comprising acrylic acid, methacrylic acid, maleic acid monomers, acrylic acid, calcium diacrylate, and / or any monomer substituted with a carboxylic acid group or a salt thereof. In some embodiments, the anionic monomer may be substituted with a carboxylic acid group and includes, for example, acrylic acid and methacrylic acid. In some embodiments, the anionic monomer that may be used herein may be a (meth)acrylamide monomer, wherein the amide group has been hydrolyzed to a carboxyl group. According to other embodiments, the monomer may be a derivative or salt of a monomer. Further examples of anionic monomers include, but are not limited to, anionic monomers comprising a sulfonic acid or a sulfonic acid group or both. In some embodiments, anionic monomers that may be used herein may comprise a sulfonic acid functional group, which may comprise, for example, 2-acrylamido-2-methylpropanesulfonic acid (acrylamido-tert-butylsulfonic acid or "ATBS"). In some embodiments, the anionic monomer may comprise an organic acid. In some embodiments, the anionic monomer may comprise acrylic acid, methacrylic acid, maleic acid, itaconic acid, acrylamidomethylpropanesulfonic acid, vinylphosphonic acid, styrene sulfonic acid, and salts thereof, such as sodium, ammonium, and potassium. In other embodiments, the anionic monomer may comprise acrylic acid, methacrylic acid; sulfonic acid, phosphonic acid, maleic acid, itaconic acid, vinyl sulfonic acid, acrylamido-tert-butyl sulfonic acid (ATBS), acrylamido-methanesulfonic acid, acrylamido-ethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinyl phosphonic acid, and their alkali metal salts, alkaline earth metal salts, and ammonium salts. The anionic monomers may be combined, for example, to form a terpolymer of acrylamide, acrylic acid, and acrylamido-tert-butyl sulfonic acid (ATBS). In an exemplary embodiment, one or more acrylamide polymers (polymers) may comprise at least one monoolefinically unsaturated monomer containing an acid group, such as a monomer containing at least one group selected from -COOH, SO3H, or -PO3H2. Examples of such monomers may include, but are not limited to, acrylic acid, methacrylic acid, vinyl sulfonic acid, allyl sulfonic acid, or 2-acrylamido-2-methylpropanesulfonic acid, particularly preferably acrylic acid and / or 2-acrylamido-2-methylpropanesulfonic acid, and most preferably acrylic acid or a salt thereof. In one exemplary embodiment, one or more acrylamide polymers (copolymers), or each of one or more acrylamide polymers (copolymers), may contain acrylic acid and / or 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof.

[0131] As used herein, the term "cationic monomer" generally refers to a monomer that has a positive charge. Examples of this include the monomer acryloyloxyethyltrimethylammonium chloride (Q9). The cationic monomer may also be selected from acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate Methyl sulfate quaternary salts, dimethylaminoethyl methacrylate benzyl chloride quaternary salts, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, and methacrylamide dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salts, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salts, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; and diallyl dialkylammonium halides, including but not limited to diallyl diethylammonium chloride and diallyl dimethylammonium chloride (“DADMAC”), and any combination thereof.

[0132] unit

[0133] As used herein, the term “ppm” refers to parts per million (e.g., mg / L) based on milligrams of solute per liter of aqueous solution or slurry.

[0134] As used herein, the term “ppb” refers to parts per billion (e.g., µg / L) based on milligrams of solute per liter of aqueous solution or slurry.

[0135] As used herein, the phrase “weight%” or “wt.%” means the dry weight of additives in a formulation, solution or slurry multiplied by 100% of the dry weight of solids.

[0136] Detailed description of the invention

[0137] This invention provides a method for removing oxygen from monomers to improve batch processing times for the production of dry polyacrylamide (DPAM) and emulsion polyacrylamide (EPAM) in polymerization processes. Regarding DPAM, this novel method and design can be directly applied to, for example, tilting reactors, but can also be applied to other new technologies, such as tubular reactors. It can be applied to both anionic and cationic DPAM, and more specifically, to production sites worldwide. In the future, it may also be introduced into new facilities, such as those using tubular reactors.

[0138] Currently, the degassing process is carried out through deep tubing within a tilting reactor, which is quite slow and can be accelerated by degassing during monomer transfer. When combined with plant improvements, production capacity can be increased by up to 19%. This capacity increase results in reducing degassing time from the current 40-60 minutes to almost zero.

[0139] In this invention, degassing can be performed repeatedly by injecting nitrogen into a Venturi injector. The kinetic energy of the monomer solution (the power source of the Venturi injector) draws the gas (i.e., N2) into the monomer solution. The method of this invention also employs pressurized, flow-controlled N2 entering the Venturi injector. Mathematical modeling of the process shows that a target level of 200 ppb is feasible if sufficient residence time and turbulence exist in the pipeline after the injector.

[0140] The pilot plant degassing unit was designed and constructed based on previous modeling work. Modeling results showed that, assuming good two-phase mixing, preferably under turbulent conditions, it is theoretically possible to achieve oxygen specifications with one-pass flow by increasing the residence time. Therefore, to verify this assumption, a pilot plant was designed to test different tube length and diameter configurations. When scaled up, the benefits of the method and apparatus of this invention include: (i) increased capacity, (ii) reduction of degassing time from 40-60 minutes to almost zero, and (iii) savings in N2 consumption.

[0141] Venturi injector using pressurized N2

[0142] Venturi ejectors have been successfully used in gas-liquid operations, such as water treatment and wastewater aeration. In absorption processes, the Venturi effect is used to draw gas into the liquid flow through a small orifice, thereby allowing the gas to dissolve in the liquid.

[0143] This is commonly used in gas scrubbers, where gases are removed from exhaust streams. In desorption processes, the Venturi effect can be used to introduce gas into a liquid stream, allowing the gas to bubble and escape from the liquid. This is commonly used in stripping processes, where gas is used to remove volatile components from a liquid. Overall, the use of Venturi ejectors in industry provides an effective and efficient method for enhancing gas-liquid mass transfer in a wide range of applications.

[0144] The Venturi effect creates a vacuum, drawing gas into the liquid flow through a small orifice, thus generating efficient mass transfer. Furthermore, the vacuum created by the Venturi effect eliminates the need for mechanically induced airflow, making the system quite cost-effective in terms of capital expenditure (CAPEX) and easy to operate.

[0145] The (N2) jet entering the liquid flow can be characterized by several variables, including jet diameter, pipe diameter, velocity ratio, and pipe Reynolds number. An important dimensionless parameter is the jet state parameter, which determines the mixing efficiency. The variables studied using a pilot-scale unit are pipe diameter, pipe length, unit temperature, dynamic flow rate, and N2 flow rate.

[0146] This invention improves degassing efficiency by feeding pressurized and flow-rate controlled nitrogen into a Venturi ejector. The system includes an N2 tank, a monomer feed tank with cooling coils and agitator, a screw pump, a Venturi ejector, 6m or 12m of piping (to increase residence time), a degasser, a discharge tank, a pressure sensor, a flow meter, a rotor flow meter, and a dissolved oxygen meter (for measuring DO in the monomer before and after passing through the ejector).

[0147] More specifically, the present invention provides a method based on Figure 1 An apparatus for degassing monomer compositions, the apparatus comprising: a monomer transport tank (20) having a monomer transport tank bottom discharge valve (5) and a monomer transport tank valve (2); and a test water transport tank (19) having a test water transport tank bottom discharge valve (4) and a test water transport tank valve (1) for feeding into a transport discharge manifold (35). The manifold (35) feeds into a transport pump carriage (21) having a transport pump carriage valve (3). Waste is discharged into a waste transport tank (6).

[0148] The delivery pump carriage (21) pumps liquid into a single feed tank equipped with a cooling coil and an agitator (22). The cooling coil is attached to a cold water control valve (11), a cold water supply valve (12), and a cold water return valve (13). The agitator is connected to an agitator valve (36).

[0149] The feed tank (22) is discharged into the screw pump (23) through the feed tank discharge valve (15), and the screw pump is fed into the Venturi ejector (25) through the pipeline. The Venturi ejector includes a power fluid inlet (32), a Venturi ejector gas inlet (33) and a Venturi ejector outlet (34).

[0150] The Venturi ejector outlet (34) is connected to a static mixer (26) and a coiled pipe (27) that serves as the feed to the degasser (hydraulic separator and vent) (28). After gas-liquid separation, the degassed solution is fed through the hydraulic separator vent valve (14) into a discharge tank (29) equipped with a DO probe (30). The discharge tank is equipped with a discharge tank vent valve (7).

[0151] Pressurized nitrogen is fed from the nitrogen tank (pressurized N2 source) (24) into the venturi injector gas inlet (33) through the nitrogen tank valve (8), the nitrogen tank pressure regulator discharge valve (17) and the nitrogen regulator valve (18).

[0152] The nitrogen flow to the discharge tank (29) is controlled by the discharge tank N2 inlet valve (10). The nitrogen flow to the Venturi injector is controlled by the nitrogen valve of the gas flow meter (9). The N2 needle valve (16) controls the flow rate through the gas flow meter (31).

[0153] legend

[0154] (1) Test water transport box valve

[0155] (2) Individual transport box valve

[0156] (3) Transfer pump slide valve

[0157] (4) Test the drain valve at the bottom of the water transport tank

[0158] (5) Bottom drain valve of individual transport box

[0159] (6) Waste transport box

[0160] (7) Exhaust valve of discharge tank

[0161] (8) Nitrogen cylinder valve

[0162] (9) Nitrogen valve of gas flow meter

[0163] (10) N2 feed valve of discharge tank

[0164] (11) Cold water control valve

[0165] (12) Cold water supply valve

[0166] (13) Cold water return valve

[0167] (14) Hydraulic separator discharge valve

[0168] (15) Feed tank discharge valve

[0169] (16) N2 needle valve

[0170] (17) Nitrogen tank pressure regulator discharge valve

[0171] (18) Nitrogen regulator valve

[0172] (19) Test water transport tank

[0173] (20) Individual transport box

[0174] (21) Conveyor pump carriage

[0175] (22) A single feed tank with cooling coils and agitator

[0176] (23) Screw pump

[0177] (24) Nitrogen tank (pressurized N2 source)

[0178] (25) Injector (Venturi injector)

[0179] (26) Static mixer

[0180] (27) Coiled pipe

[0181] (28) Degasser (hydraulic separator and exhaust port)

[0182] (29) Discharge tank

[0183] (30) Dissolved oxygen (DO) probe

[0184] (31) Gas flow meter

[0185] (32) Power fluid inlet of the ejector (Venturi ejector)

[0186] (33) Gas inlet of the ejector (Venturi ejector)

[0187] (34) Injector (Venturi injector) outlet

[0188] (35) Transporting exhaust manifolds

[0189] (36) Agitator valve

[0190] The methods, compositions, and apparatuses disclosed illustratively herein may be practiced in the absence of any elements not specifically disclosed herein and / or any elements specifically disclosed herein. Exemplary embodiments of the invention and their advantages will be further disclosed in the following examples.

[0191] Example

[0192] The embodiments provided herein are for illustrative purposes only, in order to provide a more complete understanding of the invention. These embodiments should not be construed as limiting the invention in any way.

[0193] Example 1: Design of Degassing Test Unit and Degassing Program

[0194] Degassing test unit design

[0195] The apparatus of the present invention for repeatedly deoxygenating a monomer solution comprises an N2 tank, a monomer feed tank with a cooling coil and a stirrer, a screw pump, a Venturi ejector, a 6m or 12m pipe coil for increasing additional residence time, a deaerator, a discharge tank, a DO meter for measuring dissolved oxygen (DO) before and after the monomer passes through the Venturi ejector (ejector), a pressure sensor, a flow meter, a rotor flow meter, and according to... Figure 1 Another component of the diagram.

[0196] Figure 2-3 Exemplary CAD renderings showing different views of the degassing test unit of the present invention are provided. Figure 4-7 Exemplary images showing different views of the pilot layout of a degassing test unit built in Aberdeen, USA.

[0197] Simplified degassing procedure

[0198] The simplified experimental procedure consists of the following steps:

[0199] (A) Pump the monomer solution into the monomer feed tank and determine the initial DO;

[0200] (B) Begin stirring and cool the monomer to the desired temperature (i.e., low enough to prevent polymerization).

[0201] (C) Set the required N2 flow rate;

[0202] (D) Set the required power flow rate;

[0203] (E) Begin pumping the monomer solution through the system;

[0204] (F) Measure the final DO reading of the degassed monomer solution after one pass;

[0205] (G) The N2 flow rate, dynamic flow rate, pipe inner diameter and pipe length can be adjusted, and the process can be repeated if necessary to achieve a target DO content of ≤ 500 ppb or a preferred target DO content of ≤ 200 ppb.

[0206] (H) The degassed monomer solution may (i) be recycled through the degassed system in a second (or third, fourth, etc.) pass, (ii) be stored in a storage tank, preferably under a N2 atmosphere, or (iii) be subjected to polymerization conditions.

[0207] Degassing process of aqueous solution

[0208] use Figure 1 The described apparatus and the complete experimental procedure consist of the following steps:

[0209] 1. Test water operation

[0210] 1.1. Connect all flexible hoses as shown in the flowchart of the monomer solution degassing test equipment.

[0211] 1.2. Ensure all valves are in the closed position.

[0212] 1.3. Connect the hose from the test water transport tank (19) to the transport discharge manifold (35).

[0213] 1.4. Connect the hose from the transport discharge manifold to the inlet of the delivery pump carriage (21).

[0214] 1.5. Connect the hose from the outlet of the delivery pump carriage (21) to the unit feed tank (22).

[0215] 1.6. Open the drain valve (4) at the bottom of the test water transport tank.

[0216] 1.7. Open valve (1) on the transport and discharge manifold (35).

[0217] 1.8. Open the valve (3) on the transfer pump slide (21).

[0218] 1.9. Ensure that the test water transport box (19) is ventilated.

[0219] 1.10. Start the transfer pump carriage (21).

[0220] 1.11. Fill the monomer feed tank (22) to the required level and stop the pump.

[0221] 1.12. Open the feed tank discharge valve (15).

[0222] 1.13. Open the hydraulic separator discharge valve (14).

[0223] 1.14. Open the nitrogen tank valve (8).

[0224] 1.15. Set the required pressure using the nitrogen tank pressure regulator discharge valve (17).

[0225] 1.16. Open the regulator valve (18).

[0226] 1.17. Open the N2 manifold valve (9) of the gas flow meter.

[0227] 1.17.1. Adjust the N2 flow rate using the flow meter needle valve (16) located at the bottom of the flow meter.

[0228] 1.17.2. The N2 flow rate range is 10-100 SCFH; 4.72 L / min-47.2 L / m.

[0229] 1.18. Open the N2 manifold valve (10) to cover the discharge tank (29).

[0230] Close in 1.18.1.30 seconds.

[0231] 1.19. Set the desired frequency on the pump variable frequency drive (VFD) and press the start button.

[0232] 1.20. Press the stop button on the VFD to stop the pump.

[0233] 2. Cold water control of feed tank

[0234] 2.1. Connect the cold water return booster pump to the return hose of the cooling coil in the feed tank.

[0235] 2.1.1. Cold water flows from the cooling coil of the feed tank to the cold water return valve (13).

[0236] 2.2. Open the cold water supply valve (12) and the cold water return valve (13).

[0237] 2.3. The cold water is controlled by the cold water control valve (11) above the individual feed tank (22).

[0238] 2.4. Open the air supply valve of the pneumatic motor of the feed tank mixer to circulate the water in the feed tank.

[0239] 3. Empty the discharge tank

[0240] 3.1. If the monomer solution test is completed.

[0241] 3.1.1. Connect the hose from the transfer pump carriage (21) to the top of the waste handling container (6).

[0242] 3.2. If the test water is to be reused for calibration.

[0243] 3.2.1. Connect the hose from the delivery pump carriage (21) to the test water transport box (19) or the individual feed tank (22).

[0244] 3.3. Open valve (7).

[0245] 3.4. Start the transfer pump slide (21).

[0246] 3.5. After the delivery is completed, stop the pump and close the valve (7).

[0247] 4. Monomer degassing test procedure.

[0248] 4.1. Ensure all valves are in the closed position.

[0249] 4.2. Connect the hose from the individual transport box (20) to the transport and discharge manifold (35).

[0250] 4.3. Connect the hose from the outlet of the delivery pump carriage (21) to the unit feed tank (22).

[0251] 4.4. Open the drain valve (5) at the bottom of the individual transport box.

[0252] 4.5. Open valve (2) on the transport and discharge manifold (35).

[0253] 4.6. Open the valve (3) on the transfer pump slide (21).

[0254] 4.7. Ensure that the individual transport box (20) is ventilated.

[0255] 4.8. Start the transfer pump slide (21).

[0256] 4.9. Fill the monomer feed tank (22) to the required level and stop the pump.

[0257] 4.10. Close the drain valve at the bottom of the individual transport box (5).

[0258] 4.11. Open the discharge valve (15) of the feed tank.

[0259] 4.12. Open the hydraulic separator discharge valve (14).

[0260] 4.13. Open the nitrogen tank valve (8).

[0261] 4.14. Set the required pressure using the nitrogen tank pressure regulator discharge valve (17).

[0262] 4.15. Open the N2 valve (9) of the gas flow meter (31).

[0263] 4.15.1. Adjust the flow rate using the needle valve (16) located at the bottom of the flow meter (31).

[0264] 4.15.2. The N2 flow rate range is 10-100 SCFH; 4.72 L / min-47.2 L / m.

[0265] 4.16. Open the N2 discharge tank inlet valve (10) to cover the discharge tank (29).

[0266] 4.17. Set the desired frequency on the VFD (located on the wall below the disconnect) and press the start button.

[0267] 5. If aggregation occurs

[0268] 5.1. Polymerization in the pipeline is rare. If polymerization is observed, connect the air jet line to the feed tank mixer air supply line.

[0269] 5.2. Place the open end of the air line into the container to introduce oxygen into the solution.

[0270] 5.3. If the polymerization is excessively exothermic.

[0271] 5.3.1. Open the test water transport box valve (1) on the discharge manifold (35).

[0272] 5.3.2. Insert the hose from the delivery pump carriage (21) into the tank and secure the hose.

[0273] 5.3.3. Start the transfer pump.

[0274] 6. Water rinsing after monomer testing

[0275] 6.1. When the individual test is completed or the pipeline is certain to be ruptured, flush the system with water.

[0276] 6.2. Close the cold water supply valve (12) and the cold water return valve (13).

[0277] 6.3. Use a screw pump to empty all the monomers in the feed tank (22).

[0278] 6.4. Follow the “Evacuation Tank Procedure”.

[0279] 6.5. After the delivery is completed, stop the pump and close the exhaust valve of the discharge tank (7).

[0280] 6.6. Ensure that the hose from the test water transport tank (19) to the transport discharge manifold (35) is connected.

[0281] 6.7. Connect the hose from the outlet of the delivery pump carriage (21) to the unit feed tank (22).

[0282] 6.8. Open the drain valve (4) at the bottom of the test water transport tank. Open the valve (1) on the transport drain manifold (35).

[0283] 6.9. Open the valve (3) on the delivery pump slide.

[0284] 6.10. Ensure that the test water transport box (19) is ventilated.

[0285] 6.11. Start the transfer pump slide (21).

[0286] 6.12. Fill the feed tank to the required level and stop the pump.

[0287] 6.13. Follow the steps in 3. Test water run to fill monomer feed tank (22).

[0288] 6.14. Rinse at 60 Hz on the VFD until the monomer feed tank (22) is empty.

[0289] 6.15. Follow procedure 5 again. Empty the discharge tank into the waste transfer container (6).

[0290] 6.15.1. Keep valve (2) open to flush the pipeline of the unit transport box (20).

[0291] 6.16. Close the cold water supply valve (12) and the cold water return valve (13).

[0292] Example 2: Modeling of DO variation with pipeline length

[0293] According to Example 1, the influence of the pipe coil length (27) (i.e., pipe length) on the final DO content of the degassed aqueous monomer solution was modeled for the design of the degassing test unit. Figure 8 A graph showing the modeling results is provided.

[0294] The modeling results indicate that the final DO content of the solution, predicted by modeling, is closely related to the length of the coiled tubing downstream of the N2 jet in the Venturi ejector (25). It is reasonable to conclude from these results that the residence time of the gas-liquid mixture in the tubing between the Venturi ejector (25) and the degasser (28) will allow for a more efficient mass action of DO between the liquid and gas phases, and will also allow more time for N2 to react with O2 to form nitric oxide. Nitric oxide is a gaseous product of N2 deoxygenation and is separated from the aqueous solution at the degasser along with N2, O2, and other volatile components of the gas / liquid mixture. It is reasonable to conclude from these modeling results that a longer tubing will allow for a longer residence time and longer contact between N2 and O2, resulting in higher degassing efficiency.

[0295] Example 3: Pilot-scale degassing of water-ethylene glycol solution (one pass)

[0296] Pilot-scale degassing tests were conducted with a water-ethylene glycol solution to evaluate the degassing system of the present invention, which is safer than monomer mixtures in terms of motive flow rate. Degassing was performed according to Example 1.

[0297] Several variables were adjusted to determine the relative effect of variance on the final Do content after one pass, which was used as a measure of degassing efficiency. The driving flow rate varied between 2.3 and 10.2 L / min. The initial ethylene glycol solution temperature varied between -1.1°C and 5.5°C. The coil tubing length was 6 m or 12 m. The coil tubing inner diameter varied between 4.6 and 10.9 mm. The N2 flow rate varied between 50 and 100 standard cubic feet per hour (SCFH). Table 1 shows the experimental conditions and results after one pass.

[0298] Table 1: Results of degassing of water-ethylene glycol solution.

[0299]

[0300] The results indicate that the method for deoxygenation of the present invention effectively reduces the DO content of ethylene glycol-water solutions from over 10 ppm to 1.570-0.34 ppm, typically below the target of 500 ppb after one pass. The most effective deoxygenation test results were 34 ppb, 90 ppb, and 201 ppb. These results match or exceed the preferred target DO content of 200 ppb after one pass.

[0301] Surprisingly, these results revealed that coil pipe length was only weakly correlated with degassing efficiency. Using shorter pipe lengths (e.g., 6 m), final DO contents were observed to be well below 500 ppb, as low as 201 ppb. These results are surprisingly inconsistent with the modeling results of Example 2, which predicted a strong correlation between pipe length and degassing efficiency. In contrast, these results from Example 3 indicate that the dynamic flow rate and pipe inner diameter have the greatest impact on the final DO content.

[0302] These results provide preliminary proof of concept that the method and apparatus of the present invention are highly effective for degassing aqueous solutions after one pass. The main conclusion drawn from these results is that a pipe length of 6 m appears to be sufficient; therefore, the additional 6 m is not as crucial as initially assumed. The most important parameters appear to be the dynamic flow rate and the pipe diameter.

[0303] Unbound by theory, these results demonstrate the critical importance of ensuring a high Reynolds number for system effectiveness. A higher Reynolds number indicates less laminar flow and more turbulent flow. The results strongly suggest that achieving an optimal high Reynolds number for the Venturi ejector is essential for the production-scale degassing of monomer solutions.

[0304] Example 4: Pilot-scale test of degassing monomer mixture in one pass

[0305] To evaluate the degassing system of the present invention, pilot-scale degassing tests were conducted using an aqueous monomer solution (acrylamide, 38 wt.% active). The monomer mixture represents production in an industrial plant. Degassing was performed according to Example 1.

[0306] Several variables were adjusted to determine the relative effect of variance on the final Do content after one pass, which was used as a measure of degassing efficiency. The driving flow rate varied between 5.2 and 11.9 L / min. The initial ethylene glycol solution temperature was -1.1°C or 3.5°C. The coil length was 6 m or 12 m. The coil inner diameter varied between 7.7 mm and 10.9 mm. The N2 flow rate was 80 standard cubic feet per hour (SCFH) or 100 SCFH. Table 2 shows the experimental conditions and results after one pass.

[0307] Foaming was observed in several runs, particularly at higher N2 flow rates. This fact may have affected the DO readings; however, the expected trend is reliable. The N2 flow rate measurements in the last three experiments in Table 2 are inaccurate; the reported values ​​correspond to the experimental design but not to the actual measured flow rates.

[0308] Table 2: Results of monomer mixtures (acrylamide aqueous solution, 38 wt.% activity)

[0309]

[0310] The results indicate that the deoxygenation method of the present invention effectively reduces the DO content of aqueous monomer solutions from over 13 ppm to 1.7-0.41 ppm, typically below the target of 500 ppb after one pass. These results strongly suggest that a preferred target DO content of 200 ppb can likely be achieved after one pass.

[0311] Statistical analysis of degassing results

[0312] Statistical analysis was performed on all results. Figure 9 A summary graph of the statistical effects of key parameters on DO content is shown. Longer bars indicate a greater impact on the final DO content. The most relevant variable influencing the summary results is the flow rate, followed by the pipe diameter. The least relevant variable is the pipe length.

[0313] These results are consistent with the surprising trend observed in the ethylene glycol-water deoxygenation experiment and further confirm the surprising results observed in the water-ethylene glycol experiment of Experiment 3, indicating that coil pipe length is not very important for efficient degassing. The most efficient deoxygenation experiment was achieved with a pipe length of 6 m and produced a final DO of 412 ppb. These results are surprisingly inconsistent with the modeling results of Example 2, which predicted that pipe length would be closely related to degassing efficiency.

[0314] These results suggest that residence time (related to pipe length) is not as important as initially indicated by modeling. The more significant variable appears to be the kinetic flow rate, followed by pipe ID, and then the N2 velocity. The kinetic flow of the Venturi ejector (creating a vacuum at 3 gpm) can only generate a few ounces of vacuum. Pressurizing N2 into the Venturi ejector results in the fragmentation and atomization of fine N2 bubbles (the smaller the bubbles, the larger the surface area for the N2 to react with O2). This is why N2 pressurization has a significant impact on process efficiency.

[0315] Unbound by theory, these results highlight the critical importance of ensuring a high Reynolds number (through the use of high dynamic flow and pressurized N2) for system effectiveness. A higher Reynolds number indicates less laminar flow and more turbulent flow. Due to the turbulence generated by the high dynamic flow and pressurized N2 entering the Venturi ejector, a larger pipe ID can be used to provide a larger volume, thus enabling more efficient mixing. The results strongly suggest that achieving an optimal high Reynolds number for the Venturi ejector is crucial for the production-scale degassing of monomer solutions.

[0316] Figure 10 A plot of dissolved oxygen (DO) predictions is shown, illustrating the relationship between actual DO and predicted DO. The results of this statistical analysis indicate that the selected parameters provide a satisfactory description of the results.

[0317] Figure 11 Statistical curves illustrating the effects of key parameters on DO content and degassing time are shown. Target levels are represented by horizontal dashed lines. The blue lines represent the boundary conditions for achieving the target final DO level (e.g., 500 bbp or lower) and pumping time (e.g., 25 minutes). The steepness of each curve in the graph indicates the correlation of each variable. The steeper the slope (center black line), the greater the influence of the variable on the final DO or pumping time.

[0318] Figure 11 The results shown illustrate the impact of each operating variable on the target variables (DO and pumping time). These results further confirm that the most relevant variable is the dynamic flow rate, followed by the pipe diameter. Although the preferred target value of 200 ppb was not achieved in the tests, a maximum dynamic flow rate of 10.2 L / min was set due to the technical limitations of the available pumps. Furthermore, the smaller pipe diameter prevented achieving higher flow rates due to the lack of pumping capacity. Therefore, the system can be improved to obtain a preferred target DO of ≤ 200 ppb.

Claims

1. A method of degassing a monomer composition, the method comprising: (a) providing or generating a liquid monomer composition in a feed tank, wherein the monomer solution comprises an initial dissolved oxygen (DO) content; (b) cooling the monomer solution to a temperature below 10 °C, thereby forming a cooled monomer composition; (c) injecting a jet of N2 gas into a gas inlet of a Venturi Injector at a N2 flow rate; (d) pumping the cooled monomer composition into a motive fluid inlet of the Venturi Injector at a motive flow rate, and allowing the jet of N2 gas to contact the cooled monomer composition, thereby forming a gas-liquid mixture; (e) pumping the gas-liquid mixture through a length of tubing having an inner diameter (ID); and (f) pumping the gas-liquid mixture through a degasser and allowing gas-liquid separation to occur, thereby forming a degassed monomer composition having a final DO content; wherein steps (a)-(f) are performed in the order recited.

2. The method of claim 1, further comprising: (i) determining the initial DO content of the liquid monomer composition and / or the cooled monomer composition; and (ii) after step (f), determining the final DO content of the degassed monomer composition.

3. The method of claim 1 or 2, wherein: (i) the initial DO content ranges from 2-20 ppm, 4-18 ppm, 8-16 ppm, or 10-14 ppm; and / or (ii) the final DO content comprises a desired DO content ranging from < 500 ppb, 10-500 ppb, 50-450 ppb, 100-400 ppb, or 200-300 ppb.

4. The method of any one of the preceding claims, further comprising: (i) pumping the gas-liquid mixture through a static mixer located upstream of the length of tubing; (ii) pumping the degassed monomer composition to a drain tank or storage tank; (iii) pumping the degassed monomer composition to a polymerization reactor, wherein a polymerization reaction is initiated; (iv) optionally, after the step (f) of claim 1, if the final DO content is greater than the desired DO content and / or if further degassing is desired, recirculating the degassed monomer composition to the feed tank and subjecting the degassed monomer composition to a second degassing pass comprising repeating the steps (b)-(g) of claim 1; (v) optionally, subjecting the degassed monomer composition to a third degassing pass, a fourth degassing pass, and / or a fifth degassing pass, wherein the third degassing pass, the fourth degassing pass, and / or the fifth degassing pass comprise subsequently recirculating the degassed monomer composition to the feed tank and repeating the steps (b)-(g) of claim 1; or (vi) any combination of (i)-(v).

5. The method of any one of the preceding claims, wherein: (i) the feed tank comprises a cooling means and a means of agitating the liquid monomer composition; (ii) the temperature is sufficiently low to prevent polymerization of the liquid monomer composition and ranges from -5 °C to 10 °C; 0-10 °C or 3-5 °C; (iii) the motive flow rate is controlled by a screw pump arranged in-line between the feed tank and the venturi ejector; (iv) the N2 flow rate is controlled by a gas flow meter and one or more pressure regulators, regulator valves, and / or needle valves arranged in-line between a pressurized N2 source and the venturi ejector; (v) the gas-liquid mixture comprises a Reynolds Number (Re) ranging from 2300-8000, 3000-8000, 4000-8000, or 4000-6000 and / or comprises turbulent flow when the gas-liquid mixture is flowing (i) downstream of the venturi ejector, (ii) between the venturi ejector and the degasser, or (iii) within the length of pipe; (vi) the gas-liquid mixture comprises the cooled monomer composition and finely divided N2, the finely divided N2 comprising dissolved N2, atomized N2, microscopic N2 bubbles, and / or macroscopic N2 bubbles, wherein the finely divided N2 is sufficiently small to allow gas-liquid mass transfer of DO, dissolved gases, and / or volatile molecules from the cooled monomer composition to the finely divided N2, thereby allowing removal of the DO, the dissolved gases, and / or the volatile molecules from the cooled monomer composition; (vii) the length of pipe provides a residence time for the gas-liquid mixture between the venturi ejector and the degasser and optionally comprises a coiled pipe; (viii) the degasser comprises a hydrocyclone and a gas vent; or (ix) any combination of (i)-(viii).

6. The method of any one of the preceding claims, wherein one or more of the following is adjusted to achieve a desired final DO content: (i) the Reynolds number characterizing the gas-liquid mixture; (ii) the N2 flow rate; (iii) the motive flow rate; (iv) the inner diameter (ID) of the length of pipe; (v) the length (L) of the length of pipe; or (vi) any combination of (i)-(v).

7. The method of any one of the preceding claims, wherein the liquid monomer composition comprises: (a) an aqueous monomer solution comprising water and at least one monomer, the at least one monomer comprising one or more non-ionic monomers, one or more anionic monomers, one or more cationic monomers, or any combination thereof; wherein (i) the one or more non-ionic monomers are selected from the group of primary amide containing monomers comprising acrylamide, methacrylamide, ethyl acrylamide, crotonamide, N-methyl acrylamide, N-butyl acrylamide, N-ethyl methacrylamide, and any combination thereof; (ii) the one or more cationic monomers are selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyl dimethyl ammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylate and methacrylate esters and their quaternary or acid salts, including but not limited to dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEMA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate methyl ester quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate methyl ester quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamide and methacrylamide and their quaternary or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide sulfate methyl ester quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide sulfate methyl ester quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl dimethyl ammonium chloride and diallyl dimethyl ammonium chloride ("DADMAC"), and any combination thereof; and (iii) the one or more anionic monomers contain a functional group selected from the group consisting of carboxylic acid, sulfonic acid, phosphonic acid, their corresponding water soluble salts, their corresponding water dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamidotert-butyl sulfonic acid (ATBS), acrylamidomethyl sulfonic acid, acrylamidoethyl sulfonic acid, 2-hydroxy-3-acrylamidopropyl sulfonic acid, styrene sulfonic acid, and vinyl phosphonic acid, their corresponding alkali, alkaline earth, and ammonium salts, and any combination thereof; (b) comprises 1-70 wt%, 5-50 wt%, 25-45 wt%, or 30-40 wt% of the at least one monomer; or (c) any combination of (a)(i)-(iii) and / or (b).

8. The method of any of the preceding claims, wherein (a) the liquid monomer composition comprises acrylamide, acrylic acid, acrylamidyl tertiary butyl sulfonic acid (ATBS), or any combination thereof; or (b) the degassed monomer composition is used to produce dry polyacrylamide (DPAM) or emulsion polyacrylamide (EPAM).

9. The method of any of the preceding claims, wherein: (a) the method results in the degassed monomer composition having the desired final DO content after a first degassing pass, wherein the first degassing pass comprises a single application of the steps (a)-(f) according to claim 1; and / or (b) the method results in (i) increased monomer degassing capacity, (ii) reduced monomer degassing time, (iii) reduced N2consumption, or (iv) any combination of (i)-(iii), as compared to a conventional method of degassing a monomer composition, which comprises sparging N2gas through a pipe or bubble column into a bulk monomer composition in a reactor or storage tank.

10. A degassed monomer composition obtainable by the method of any of claims 1-9, wherein the degassed monomer composition comprises a desired final DO content in the range of < 500 ppb, 10-500 ppb, 50-450 ppb, 100-400 ppb, or 200-300 ppb.

11. An apparatus for degassing a monomer composition, the apparatus comprising: (a) a monomer feed tank comprising cooling means and means for agitating a liquid monomer composition, optionally comprising a liquid monomer composition comprising the initial dissolved oxygen (DO) content according to any of claims 1, 3, 7, or 8; (b) means for controlling a motive flow rate of the liquid monomer composition, a pipe, and a venturi eductor comprising a motive fluid inlet, a gas inlet, and an outlet, wherein the means for controlling the motive flow rate and the pipe are disposed in-line between the monomer feed tank and the motive fluid inlet on the venturi eductor; (c) a pressurized N2source and means for controlling an N2flow rate, which means are disposed in-line with the gas inlet on the venturi eductor; and (d) a length of pipe having an internal diameter (ID) and a degasser, wherein the length of pipe is disposed in-line between the outlet on the venturi eductor and the degasser.

12. The apparatus of claim 11, further comprising: (a) a dissolved oxygen (DO) meter disposed in contact with the liquid monomer composition and upstream of the venturi eductor; and / or (b) a degassed monomer composition outlet; and / or (c) a degassed monomer composition outlet; and / or (d) a degassed monomer composition outlet; and / or (e) a degassed monomer composition outlet; and / or (f) a degassed monomer composition outlet; and / or (g) a degassed monomer composition outlet; and / or (h) a degassed monomer composition outlet; and / or (i) a degassed monomer composition outlet; and / or (j) a degassed monomer composition outlet; and / or (k) a degassed monomer composition outlet; and / or (l) a degassed monomer composition outlet; and / or (m) a degassed monomer composition outlet; and / or (n) a degassed monomer composition outlet; and / or (o) a degassed monomer composition outlet; and / or (p) a degassed monomer composition outlet; and / or (q) a degassed monomer composition outlet; and / or (r) a degassed monomer composition outlet; and / or (s) a degassed monomer composition outlet; and / or (t) a degassed monomer composition outlet; and / or (u) a degassed monomer composition outlet; and / or (v) a degassed monomer composition outlet; and / or (w) a degassed monomer composition outlet; and / or (x) a degassed monomer composition outlet; and / or (y) a degassed monomer composition outlet; and / or (z) a degassed monomer composition outlet; and / or (aa) a degassed monomer composition outlet; and / or (bb) a degassed monomer composition outlet; and / or (cc) a degassed monomer composition outlet; and / or (dd) a degassed monomer composition outlet; and / or (ee) a degassed monomer composition outlet; and / or (ff) a degassed monomer composition outlet; and / or (gg) a degassed monomer composition outlet; and / or (hh) a degassed monomer composition outlet; and / or (ii) a degassed monomer composition outlet; and / or (jj) a degassed monomer composition outlet; and / or (kk) a degassed monomer composition outlet; and / or (ll) a degassed monomer composition outlet; and / or (mm) a degassed monomer composition outlet; and / or (nn) a degassed monomer composition outlet; and / or (oo) a degassed monomer composition outlet; and / or (pp) a degassed monomer composition outlet; and / or (qq) a degassed monomer composition outlet; and / or (rr) a degassed monomer composition outlet; and / or (ss) a degassed monomer composition outlet; and / or (tt) a degassed monomer composition outlet; and / or (uu) a degassed monomer composition outlet; and / or (vv) a degassed monomer composition outlet; and / or (ww) a degassed monomer composition outlet; and / or (xx) a degassed monomer composition outlet; and / or (yy) a degassed monomer composition outlet; and / or (zz) a degassed monomer composition outlet; and / or (aaaa) a degassed monomer composition outlet; and / or (bbbb) a degassed monomer composition outlet; and / or (cccc) a degassed monomer composition outlet; and / or (dddd) a degassed monomer composition outlet; and / or (eeee) a degassed monomer composition outlet; and / or (ff) a degassed monomer composition outlet; and / or (gg) a degassed monomer composition outlet; and / or (hh) a degassed monomer composition outlet; and / or (ii) a degassed monomer composition outlet; and / or (jj) a degassed monomer composition outlet; and / or (kk) a degassed monomer composition outlet; and / or (ll) a degassed monomer composition outlet; and / or (mm) a degassed monomer composition outlet; and / or (nn) a degassed monomer composition outlet; and / or (oo) a degassed monomer composition outlet; and / or (pp) a degassed monomer composition outlet; and / or (qq) a degassed monomer composition outlet; and / or (rr) a degassed monomer composition outlet; and / or (ss) a degassed monomer composition outlet; and / or (tt) a degassed monomer composition outlet; and / or (uu) a degassed monomer composition outlet; and / or (vv) a degassed monomer composition outlet; and / or (ww) a degassed monomer composition outlet; and / or (xx) a degassed monomer composition outlet; and / or (yy) a degassed monomer composition outlet; and / or (zz) a degassed monomer composition outlet; and / or (aaaa) a degassed monomer composition outlet; and / or (bbbb) a degassed monomer composition outlet; and / or (cccc) a degassed monomer composition outlet; and / or (dddd) a degassed monomer composition outlet; and / or (eeee) a degassed monomer composition outlet; and / or (ff) a degassed monomer composition outlet; and / or (gg) a degassed monomer composition outlet; and / or (hh) a degassed monomer composition outlet; and / or (ii) a degassed monomer composition outlet; and / or (jj) a degassed monomer composition outlet; and / or (kk) a degassed monomer composition outlet; and / or (ll) a degassed monomer composition outlet; and / or (mm) a degassed monomer composition outlet; and / or (nn) a degassed monomer composition outlet; and / or (oo) a degassed monomer composition outlet; and / or (pp) a degassed monomer composition outlet; and / or (qq) a degassed monomer composition outlet; and / or (rr) a degassed monomer composition outlet; and / or (ss) a degassed monomer composition outlet; and / or (tt) a degassed monomer composition outlet; and / or (uu) a degassed monomer composition outlet; and / or (vv) a degassed monomer composition outlet; and / or (ww) a degassed monomer composition outlet; and / or (xx) a degassed monomer composition outlet; and / or (yy) a degassed monomer composition outlet; and / or (zz) a degassed monomer composition outlet; and / or (aaaa) a degassed monomer composition outlet; and / or (bbbb) a degassed monomer composition outlet; and / or (cccc) a degassed monomer composition outlet; and / or (b) a second dissolved oxygen (DO) meter arranged to be in contact with the degassed liquid monomer composition and downstream of the degasser.

13. The apparatus of claim 11 or 12, further comprising: (a) a gas-liquid mixing means, optionally a static mixer, arranged downstream of the degasser; (b) a discharge tank, storage tank, or polymerization reactor arranged downstream of the degasser; (c) means to flow N2 into the discharge tank, the storage tank, or the polymerization reactor; (d) optionally, means to recycle the degassed liquid monomer composition into the monomer feed tank or directly into the motive fluid inlet on the venturi eductor; or (e) any combination of (a) to (d) or any combination of (a) and (c).

14. The apparatus of any one of claims 11 to 13, wherein: (a) the cooling means comprises cooling coils and the agitating means comprises an agitator; (b) the means to control motive flow rate comprises a screw pump and a monomer flow meter; (c) the means to control N2 flow rate comprises a gas flow meter and one or more N2 pressure regulators, one or more N2 regulator valves, and / or one or more N2 needle valves arranged in line between the pressurized N2 source and the gas inlet on the venturi eductor; (d) the length of piping comprises straight piping or tubing, coiled piping or tubing, or a combination thereof; (e) the degasser comprises a hydrocyclone and a gas vent; or (f) any combination of (a) to (e).

15. The apparatus of any one of claims 11 to 14, further comprising: (a) one or more pressure sensors, one or more flow meters, one or more rotameters; (b) a feed tank discharge valve arranged in line between the monomer feed tank and the screw pump; (c) a hydrocyclone discharge valve arranged downstream of the degasser; or (d) any combination of (a) to (c).

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