Hydroformylation reaction method

Abstract

To provide a good method for hydroformylation. [Solution] The present invention relates to a hydroformylation reaction method. In one embodiment, the hydroformylation reaction method includes (a) contacting an olefin with hydrogen and carbon monoxide in the presence of a homogeneous catalyst in a reactor to provide a reaction fluid, the reactor comprising one or more reaction zones; (b) removing a portion of the reaction fluid from a first reaction zone; (c) passing at least a portion of the removed reaction fluid through a shear mixer to generate bubbles in the portion of the removed reaction fluid, the hydrogen and carbon monoxide supplied to the reactor being introduced through the shear mixer; and (d) returning the removed reaction fluid to the first reaction zone through one or more nozzles, the returned reaction fluid coming out of each nozzle being a jet, the mixing energy density supplied to the reactor by the jet being 500 watts / m³ 3 That's all.

Description

Technical Field

[0001] The present invention generally relates to a hydroformylation reaction method.

[0002] Introduction Hydroformylation is a reaction of an olefin with H2 and CO in the presence of a homogeneous rhodium catalyst modified with an organic phosphorus ligand, producing an aldehyde according to the following equation.

[0003]

Equation

[0004] Typically, the hydroformylation reaction is carried out in a liquid phase in which synthesis gas (a gas mixture of H2 and CO) is sparged into a reaction fluid containing a liquid olefin, the product aldehyde, heavy materials, and a homogeneous rhodium / ligand catalyst.

[0005] In order for the reaction to occur, since H2 and CO need to be dissolved in the reaction fluid, effective gas-liquid mixing is important in both the initiation and maintenance of the hydroformylation reaction.

[0006] In addition, it is necessary to remove the heat generated by the exothermic hydroformylation reaction and control the temperature of the reactor under the desired reaction conditions. This is typically achieved by means of an internal cooling coil, or by recirculating the reaction fluid through an external heat exchanger and returning the cooled reaction fluid to the reactor, or by both.

[0007] Furthermore, under the same conditions as the above hydroformylation reaction, the obtained aldehyde may further react and be hydrogenated in situ to obtain the corresponding alcohol. And hydroformylation under amination conditions can be regarded as a variant of the hydroformylation reaction.

[0008] Another secondary catalytic activity of some hydroformylation catalysts is the hydrogenation or isomerization of double bonds (e.g., olefins with internal double bonds) to saturated hydrocarbons or α-olefins, and vice versa. Avoiding these secondary reactions of hydroformylation catalysts is crucial for establishing and maintaining specific hydroformylation reaction conditions within the reactor. Even slight deviations from process parameters can lead to the formation of significant amounts of unwanted secondary products; therefore, maintaining substantially identical process parameters across the entire volume of reaction solution in the hydroformylation reactor can be extremely important. Furthermore, a volume of the reactor where synthesis gas is not sufficiently dispersed or dissolved contributes neither to the reaction nor to the reactor's productivity. In addition, many hydrolyzable catalysts degrade in the absence of synthesis gas at reaction temperatures, and regions of low-dispersion or dissolved synthesis gas contribute to reduced catalytic performance. Alternatively, many rhodium phosphine catalysts decompose in high-CO environments, so regions of excessively dissolved synthesis gas concentrations should also be avoided. Therefore, a highly dispersed and homogeneous gas mixture (determined by high gas stagnation or gas fraction) is the most desirable result. Generally, in the hydroformylation of olefins with a homogeneous rhodium catalyst modified with an organophosphorus ligand, it is advantageous to establish optimal concentrations of hydrogen and carbon monoxide dissolved in the liquid reaction medium.

[0009] The concentration of dissolved carbon monoxide (CO) in the reaction mixture is particularly important and is a critical control variable in a hydroformylation reactor. While the dissolved CO concentration in the reaction mixture cannot be directly measured, it is typically monitored and approximated using online analyzers to determine the partial pressure of CO in the reactor's vapor space, which is presumed to be in equilibrium with the reaction liquid phase. This approximation improves when the reaction fluids in the reactor are more uniformly mixed, better approximating a fully backed-mixed reaction mixture, such as in the classical CSTR model.

[0010] To achieve a high conversion rate, reactors with multiple zones, such as those described in U.S. Patent No. 5,728,893, are preferred. However, in reactors with two or more reaction zones, measuring the CO partial pressure in the upper space only indicates the CO concentration in the upper zone, and not necessarily the CO concentration in the lower reaction zone. This becomes even more important when the upper reaction zone is not a back-mixed reactor. In the latter case, it is even more important that the feed to the non-back-mixed reaction zone is as uniform as possible in order to achieve the most uniform and / or predictable CO distribution possible.

[0011] The hydrocarbon (paraffin) formation reaction, the formation of high-boiling aldehyde condensates (i.e., high-boiling products or "heavy products"), and the decomposition rate of organophosphorus-rhodium catalysts are also affected by the reaction temperature. In the case of backmixing reactors, it is important to avoid the formation of gradients with respect to the reaction temperature and the concentration of dissolved CO in the volume of reaction liquid present in the reactor. In other words, it is important to establish and maintain nearly identical operating conditions across the entire liquid volume. Therefore, it is preferable to avoid non-uniform distribution of reactants and temperature within the reaction zone. However, other non-backmixing reactors, such as plug-flow reactors and bubble reactors, have gradients, and it is known that controlling these reactors in this way is more difficult.

[0012] Means for supplying synthesis gas and ensuring good distribution have been recognized for some time. Scientific papers, for example, focusing on stirring speed, and the technique disclosed in International Publication No. 2018 / 236823 concerning a backmix reactor without mechanical stirrers, teach that good distribution of synthesis gas is important for good reactivity and reactor performance.

[0013] Therefore, it is desirable to have a hydroformylation reactor design, preferably a multi-zone hydroformylation reactor design, that provides a highly dispersed and uniform synthesis gas and temperature distribution within the reactor without using a mechanical stirrer, thereby establishing a good initial synthesis gas distribution. [Overview of the Initiative]

[0014] The present invention relates in general to a hydroformylation reaction method for preparing aldehydes by reacting olefins with carbon monoxide and hydrogen gas in a liquid phase. In various embodiments with high temperatures of 50°C to 145°C and pressures of 1 to 100 bar in the presence of a catalyst, some of these gases are dispersed in the reaction mixture in the form of bubbles, and others are dissolved in the reaction mixture. Embodiments of the present invention can advantageously provide thorough gas-liquid mixing of the reaction fluid in the reactor without the use of a mechanical stirrer.

[0015] It has been found that by utilizing high-speed fluid flow, (1) synthesis gas can be introduced as a flow with a well-distributed flow of microbubbles, and (2) momentum and shear force can be imparted to the reaction liquid to not only mix the reactor contents but also disperse the synthesis gas bubbles, thereby uniformly distributing the bubbles and mixing the entire reaction zone. In some embodiments of the present invention, despite not being located at the top of the reactor as in the design of conventional Venturi gas-liquid mixing reactors, the entire reactor fluid can achieve remarkably uniform temperature and gas-liquid mixing, as evidenced by a higher and more uniform gas fraction or gas load within the reactor, and a constant and uniform temperature. In addition, the uniformly mixed microbubbles facilitate the introduction of process fluid into non-back-mixing reaction zones such as bubble columns or plug-flow reactors, which is difficult in Venturi-type reactor designs.

[0016] In one embodiment, the hydroformylation reaction method comprises (a) contacting an olefin with gaseous hydrogen and carbon monoxide in the presence of a homogeneous catalyst in a reactor to provide a reaction fluid, the reactor comprising one or more reaction zones; (b) removing a portion of the reaction fluid from a first reaction zone; (c) passing at least a portion of the removed reaction fluid through a shear mixer to generate bubbles in the portion of the removed reaction fluid, so that at least a portion of the hydrogen and carbon monoxide supplied to the reactor is introduced through the shear mixer; and (d) returning the removed reaction fluid to the first reaction zone through one or more nozzles, the returned reaction fluid exiting each nozzle being a jet, wherein the mixing energy density supplied to the reactor by the jets is given by the following formula:

[0017]

number

[0018] These and other embodiments are described in more detail in “Modes for Carrying Out the Invention.” [Brief explanation of the drawing]

[0019] [Figure 1]This is a schematic diagram showing an example of a hydroformylation reactor and related equipment that can be used in a hydroformylation reaction method according to one embodiment of the present invention. [Figure 2] This is a schematic diagram showing the angle and other parameters at which the nozzle can be oriented within the reactor, according to some embodiments of the present invention. [Figure 3a] Two embodiments of a shear mixing apparatus that can be used in some embodiments of the present invention are shown, where "G" represents the gas entering the shear mixing apparatus and "L" represents the liquid entering the shear mixing apparatus. [Figure 3b] Two embodiments of a shear mixing apparatus that can be used in some embodiments of the present invention are shown, where "G" represents the gas entering the shear mixing apparatus and "L" represents the liquid entering the shear mixing apparatus. [Figure 4] A series of diagrams illustrating different positions of the nozzle in the reactor, different positions of one or more donut baffles relative to the jet, and the angle of the jet exiting the nozzle, according to some embodiments of the present invention. [Figure 5] Comparative Example A and Examples 1 and 2 of the present invention are shown in color-coded gas volume fraction diagrams. [Figure 6] A color-coded diagram showing the average mass transfer coefficients (KLa) for Comparative Example A and Examples 1 and 2 of the present invention is provided. [Modes for carrying out the invention]

[0020] Hydroformation methods generally involve contacting CO, H2, and at least one olefin under hydroformation conditions sufficient to form at least one aldehyde product, in the presence of a catalyst containing a transition metal and an organophosphorus ligand as components. Optional method components include amines and / or water.

[0021] All references to the periodic table of elements and its various groups are to the version published in the CRC Handbook of Chemistry and Physics, 72nd Ed. (1991-1992), CRC Press, page I-10.

[0022] Unless otherwise stated or implied by the context, all parts and percentages are based on weight, and all test methods are as of the filing date of this application. As used herein, the term "ppmw" means parts per million by weight. For the purposes of U.S. patent practice, any referenced patent, patent application, or publication is incorporated by reference in whole (or its equivalent U.S. version) in particular with respect to definitional disclosures (to the extent that they do not conflict with any definitions specifically provided herein) and general knowledge in the art.

[0023] As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are interchangeable. “Comprise,” “include,” and their variations are not restrictive when these terms appear in the specification and claims. Thus, for example, an aqueous composition containing “a” hydrophobic polymer particles can be interpreted as meaning that the composition contains “one or more” hydrophobic polymer particles.

[0024] Furthermore, in this specification, an enumeration of numerical ranges by endpoints includes all numbers contained within that range (for example, 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). For the purposes of the present invention, it should be understood, in accordance with what those skilled in the art would understand, that a numerical range is intended to include and support all possible subranges that may be contained within that range. For example, the range 1-100 is intended to convey 1.01-100, 1-99.99, 1.01-99.99, 40-60, 1-55, etc.

[0025] As used herein, the term “hydroformylation” is intended to include, but is not limited to, all acceptable asymmetric and non-asymmetric hydroformylation methods that involve converting one or more substituted or unsubstituted olefin compounds or a reaction mixture comprising one or more substituted or unsubstituted olefin compounds into one or more substituted or unsubstituted aldehydes or a reaction mixture comprising one or more substituted or unsubstituted aldehydes.

[0026] In this specification, the terms “reaction fluid,” “reaction medium,” and “catalyst solution” are used interchangeably and may include, but are not limited to, (a) a metal-organophosphorus ligand complex catalyst, (b) free organophosphorus ligands, (c) aldehyde products formed in the reaction, (d) unreacted reactants (e.g., hydrogen, carbon monoxide, olefins), (e) a solvent for the aforementioned metal-organophosphorus ligand complex catalyst and free organophosphorus ligands, and optionally, (f) one or more ligand decomposition products (which may be homogeneous or heterogeneous, and which include those adhering to the surfaces of process equipment), such as oxides and phosphate compounds formed in the reaction. It should be understood that the reaction fluid may be a mixture of gases and liquids. For example, the reaction fluid may include bubbles entrained in the liquid (e.g., hydrogen and / or CO and / or inert substances) or gases dissolved in the liquid (e.g., hydrogen and / or CO and / or inert substances). The reaction fluid may include, but is not limited to, (a) the fluid in the reaction zone, (b) the fluid flow en route to the separation zone, (c) the fluid in the separation zone, (d) the recirculated flow, (e) the fluid drawn out from the reaction zone or separation zone, (f) the drawn-out fluid treated with a buffer solution, (g) the treated fluid returned to the reaction zone or separation zone, (h) the fluid en route to the external cooler, (i) the fluid in the external cooler, (j) the fluid returned from the external cooler to the reaction zone, and (k) ligand decomposition products and their salts.

[0027] As used herein, the term “first reaction zone” in a multi-reaction-zone reactor or reaction series refers to a reaction zone into which the majority of the catalyst is introduced (e.g., a recirculated catalyst or catalyst-containing reaction fluid from an upstream reactor not part of the present invention). “Second reaction zone” follows the first reaction zone, and so on, in that the majority of the catalyst flows from the first reaction zone to the second reaction zone. The advantages of this type of reaction scheme are described in U.S. Patent No. 5,728,893. For the purposes of the present invention, the term “first reaction zone” refers to a reaction zone into which the majority of the olefin, synthesis gas, and catalyst are introduced into the reactor. The majority of the reaction fluid leaving this first reaction zone is then transported through a perforated plate without intermediate piping to the “second reaction zone.” In this context, “first” and “second” refer to the pathways followed by the majority of the catalyst in this reactor, and it is recognized that reaction zones may exist prior to the reactor body not included in the present invention.

[0028] The present invention relates, in general terms, to a hydroformylation reaction method for preparing aldehydes by reacting olefins with carbon monoxide and hydrogen gas in a liquid phase. Embodiments of the present invention advantageously disperse at least a portion of the carbon monoxide and / or hydrogen gas in the reaction fluid in the form of small bubbles. In some embodiments, the method of the present invention can advantageously provide thorough gas-liquid mixing of the reaction fluid without the use of a mechanical stirrer.

[0029] In one embodiment, the hydroformylation process of the present invention comprises: (a) contacting an olefin, hydrogen, and carbon monoxide in the presence of a homogeneous catalyst in a reactor to provide a reaction fluid, wherein the reactor includes one or more reaction zones; (b) removing a portion of the reaction fluid from the first reaction zone; (c) passing at least a portion of the removed reaction fluid through a shear mixing device to generate bubbles in a portion of the removed reaction fluid, wherein at least a portion of the hydrogen and carbon monoxide provided to the reactor is introduced through the shear mixing device; and (d) returning the removed reaction fluid to the first reaction zone through one or more nozzles, wherein the returned reaction fluid exiting each nozzle is a jet, and the mixing energy density provided to the reactor by the jets is represented by the following formula:

[0030] [Number] (where V is the volume (m 3 ) of the reaction fluid in the first reaction zone, N is the total number of jets returned to the first reaction zone such that each jet is uniquely identified using natural numbers from i = 1 to i = N (in steps of 1), ρ i is the average density (kg / m 3 ) at the nozzle port of the reaction fluid returned to the first reaction zone through the i-th jet, Q i is the volumetric flow rate (m 3 / s) of the reaction fluid returned to the first reaction zone through the i-th jet, A i is the cross-sectional area (m 2The following conditions are met: ) ). In some embodiments, in addition to hydrogen and carbon monoxide supplied to the reactor through the shear mixer, an inert gas (e.g., methane, CO2, argon, nitrogen, etc.) may also be present in the synthesis gas supplied to the reactor through the shear mixer. In some embodiments, the average bubble size of the bubbles produced by the shear mixer is 10 nanometers to 3,000 microns. In some embodiments, the average bubble size of the bubbles produced by the shear mixer is 100 microns to 800 microns.

[0031] The flow rate of the reaction fluid through the shear mixer can be important for promoting proper mixing of the reaction fluid. In one embodiment, the flow rate of the reaction fluid through the shear mixer is as follows: q SM >525(μ o / ρ o )P SM (In the formula, q SM This is the flow rate (m³) of the reaction fluid entering the shear mixer. 3 / s) and ρ o This is the density (kg / m³) of the reaction fluid before it enters the shear mixer. 3 ) and μ o P is the viscosity (Pa·s) of the reaction fluid before it enters the shear mixer. SM This satisfies the minimum wet perimeter of the cross-section of the liquid flow inside the shear mixer.

[0032] In some embodiments, the removed reaction fluid is returned to the first reaction fluid through at least two nozzles, each nozzle oriented such that the angle of the nozzle with respect to the horizontal plane (alpha) is between +75° and -75°, and alpha, the angle of the nozzle with respect to a vertical plane passing through the center of the reactor (beta), and the distance from the vertical plane passing through the center of the reactor (phi) are all non-zero when beta is zero.

[0033] In some embodiments, hydrogen and carbon monoxide are provided as synthesis gas, and at least 20% of the synthesis gas provided to the first reaction zone passes through a shear mixer before entering the first reaction zone.

[0034] In some embodiments, at least a portion of the synthesis gas is introduced into the cylindrical reactor through a spurger at a height of less than 50% of the reaction fluid filling height of the first reaction zone.

[0035] In some embodiments, the reactor includes a horizontally oriented ring baffle mounted on the inner wall of the reactor, the ring baffle positioned at a height of less than 90% of the height of the liquid reaction fluid in the first reaction zone, and the solid portion of the ring baffle extends 5-30% of the diameter of the reactor.

[0036] In some embodiments, a stirrer is placed inside the reactor. In some embodiments, the stirrer is not operational. In some embodiments, the stirrer and the returned reaction fluid provide a mixing energy density within the cylindrical reactor.

[0037] In some embodiments, the reactor is oriented vertically.

[0038] In some embodiments, the reactor further includes a second reaction zone, and the reaction fluid flows from the first reaction zone to the second reaction zone without piping. In some further embodiments, the first and second reaction zones are separated by a perforated plate. In some embodiments, the reactor further includes a third reaction zone, and the reaction fluid flows from the second reaction zone to the third reaction zone without piping. In some further embodiments, the second and third reaction zones are separated by a perforated plate.

[0039] In some embodiments, the reactor includes a product outlet nozzle located in the lower part of the reactor and means for preventing gas entrainment, located within the bottom volume of the reactor.

[0040] The hydroformylation method of the present invention provides a reaction fluid by contacting an olefin, hydrogen, and carbon monoxide in the presence of a homogeneous catalyst in a reactor, wherein the reactor comprises one or more reaction zones.

[0041] Hydrogen and carbon monoxide may be obtained from any suitable source, including petroleum cracking and refining operations. Synthesis mixtures are a preferred source of hydrogen and CO. Synthesis gas is the name given to gas mixtures containing varying amounts of CO and H2. The methods of production are well known. Hydrogen and CO are typically the main components of synthesis gas, but synthesis gas may also contain CO2 and inert gases such as N2 and Ar. The molar ratio of H2 to CO varies considerably, but is generally in the range of 1:100 to 100:1, and usually 1:10 to 10:1. Synthesis gas is commercially available and is often used as a fuel source or as an intermediate for the production of other chemicals. The H2:CO molar ratio for chemical production is often 3:1 to 1:3, and is usually targeted at about 1:2 to 2:1 for most hydroformylation applications.

[0042] In typical embodiments of the hydroformylation method, a solvent is advantageously used. Any suitable solvent that does not excessively interfere with the hydroformylation method may be used. Examples of suitable solvents for rhodium-catalyzed hydroformylation methods include those disclosed in U.S. Patents 3,527,809, 4,148,830, 5,312,996, and 5,929,289. Non-limiting examples of suitable solvents include saturated hydrocarbons (alkanes), aromatic hydrocarbons, water, ethers, aldehydes, ketones, nitriles, alcohols, esters, and aldehyde condensation products. Specific examples of solvents include tetraglyme, pentane, cyclohexane, heptane, benzene, xylene, toluene, diethyl ether, tetrahydrofuran, butyraldehyde, and benzonitrile. Organic solvents may also contain dissolved water up to the saturation limit. Exemplary preferred solvents include ketones (e.g., acetone and methyl ethyl ketone), esters (e.g., ethyl acetate, di-2-ethylhexyl phthalate, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), hydrocarbons (e.g., toluene), nitro hydrocarbons (e.g., nitrobenzene), ethers (e.g., tetrahydrofuran (THF)), and sulfolanes. In rhodium-catalyzed hydroformylation methods, it may be desirable to use an aldehyde compound as the main solvent that corresponds to the aldehyde product to be produced and / or a higher boiling point aldehyde liquid condensation by-product that may be produced in situ during the hydroformylation method, for example, as described in U.S. Patents 4,148,830 and 4,247,486. The main solvent usually ultimately contains both the aldehyde product and the higher boiling point aldehyde liquid condensation by-product ("heavy matter") due to the nature of the continuous method. The amount of solvent is not particularly important and should be sufficient to provide the desired amount of transition metal concentration in the reaction medium. Typically, the amount of solvent ranges from about 5% to about 95% by weight, based on the total weight of the reaction fluid. A mixture of solvents may also be used.

[0043] Embodiments of the present invention are applicable to improvements of conventional continuous mixed gas-phase / liquid-phase CSTR rhodium-phosphorus complex-catalyzed hydroformylation methods for producing aldehydes in the presence of free organophosphorus ligands. Such hydroformylation methods (also referred to as “oxo” methods) and their conditions are well known in the art, as exemplified, for example, by the continuous liquid recirculation method in U.S. Patent No. 4,148,830, the phosphite-based methods in U.S. Patents No. 4,599,206 and No. 4,668,651, and also include methods described in U.S. Patents No. 5,932,772 and No. 5,952,530. Such hydroformylation methods generally involve the production of aldehydes by reacting an olefin compound with hydrogen and carbon monoxide gas in a liquid reaction medium containing a soluble rhodium-organophosphorus complex catalyst, free organophosphorus ligands, and a higher boiling point aldehyde condensation byproduct. Generally, rhodium metal concentrations ranging from approximately 10 ppm by weight to approximately 1000 ppm by weight, calculated as free metal, are sufficient for most hydroformylation methods. Some methods use rhodium concentrations of approximately 10–700 ppm by weight, often 25–500 ppm by weight, calculated as free metal.

[0044] Therefore, as in the case of rhodium-organophosphorus complex catalysts, any conventional organophosphorus ligand can be used as a free ligand, and such ligands and methods for producing them are well known in the art. A wide variety of organophosphorus ligands can be used in the present invention. Examples include, but are not limited to, phosphine, phosphine, phosphinophosphine, bisphosphine, phosphonite, bisphosphonite, phosphinite, phosphoramidite, phosphinophosphoamidite, bisphosphoramidite, and fluorophosphine. The ligand may contain a chelate structure and / or contain multiple P(III) moieties such as polyphosphine, polyphosphoramidite, and mixed P(III) moieties such as phosphine-phosphoramidite, fluorophosphine-phosphine. Of course, mixtures of such ligands can also be used as needed. Therefore, the hydroformylation method of the present invention can be carried out with any excess amount of free phosphorus ligand, for example, at least 0.01 moles of free phosphorus ligand per mole of rhodium metal present in the reaction medium. Generally, the amount of free organophosphorus ligands used depends only on the desired aldehyde product, as well as the olefin and complex catalyst used. Therefore, for most purposes, the amount of free phosphorus ligands present in the reaction medium is in the range of approximately 0.01 to 300 or more per mole of rhodium present (measured as free metal). For example, generally, large amounts of free triarylphosphine ligands, such as triphenylphosphine, including more than 50 moles, and sometimes more than 100 moles, per mole of rhodium, have been used to achieve satisfactory catalytic activity and / or catalytic stabilization. Other phosphorus ligands, such as alkylarylphosphines and cycloalkylarylphosphines, can also help provide acceptable catalytic stability and reactivity without excessively hindering the conversion of certain olefins to aldehydes, even when the amount of free ligands present in the reaction medium is only 1 to 100 moles, and sometimes 15 to 60 moles, per mole of rhodium present.In addition, other phosphorus ligands (e.g., phosphines, sulfonated phosphines, phosphites, diorganophosphites, bisphosphites, phosphoramidites, phosphonites, fluorophosphites) can help provide acceptable catalytic stability and reactivity without hindering the conversion of certain olefins to aldehydes, even when the amount of free ligands present in the reaction medium is as low as 0.01 to 100 moles, and in some cases as low as 0.01 to 4 moles, per mole of rhodium present.

[0045] More specifically, exemplary rhodium-phosphorus complex catalysts and exemplary free phosphorus ligands are disclosed, for example, in U.S. Patent Nos. 3,527,809, 4,148,830, 4,247,486, 4,283,562, 4,400,548, and 4,482,749, European Patent Application Publications Nos. 96,986, 96,987, and 96,988 (all published on December 28, 1983), and International Publication No. 80 / 01690 (published on August 21, 1980). Among the more preferred ligands and complex catalysts that may be mentioned are, for example, the triphenylphosphine ligand and rhodium-triphenylphosphine complex catalyst of U.S. Patent Nos. 3,527,809, 4,148,830 and 4,247,486, the alkylphenylphosphine and cycloalkylphenylphosphine ligand of U.S. Patent No. 4,283,562, and the rhodium-alkylphenylphosphine and rhodium-cycloalkylphenylphosphine complex catalyst, and the diorganophosphine ligand and rhodium-diorganophosphine complex catalyst of U.S. Patent Nos. 4,599,206 and 4,668,651.

[0046] As further described above, hydroformylation reactions are typically carried out in the presence of higher-boiling aldehyde condensation byproducts. The nature of the sequential hydroformylation reactions available herein is that they generate such higher-boiling aldehyde byproducts (e.g., dimers, trimers, and tetramers) in situ during the hydroformylation method, as described more fully, for example, in U.S. Patents 4,148,830 and 4,247,486. Such aldehyde byproducts provide excellent carriers for liquid catalyst recycling methods. For example, initially, the hydroformylation reaction can be carried out in the absence or presence of small amounts of higher-boiling aldehyde condensation byproducts as the solvent for the rhodium complex catalyst, or the reaction can be carried out in the presence of 70% by weight, even 90% by weight, or even more, of such condensation byproducts based on the total liquid reaction medium. In general, weight ratios of aldehyde to higher boiling aldehyde condensation byproducts in the range of approximately 0.5:1 to 20:1 are sufficient for most purposes. Furthermore, it should be understood that small amounts of other conventional organic cosolvents may be present if necessary.

[0047] As described above, the hydroformylation reaction conditions can vary over a wide range, but generally, it is more preferable to carry out the method at a total gas pressure of less than about 3100 kilopascals (kPa) of hydrogen, carbon monoxide, and the olefin unsaturated starting compound, more preferably less than about 2415 kPa. The minimum total pressure of the reactants is not particularly important and is limited mainly by the amount of reactants required to obtain the desired reaction rate. More specifically, the partial pressure of carbon monoxide in the hydroformylation reaction method of the present invention can be about 1 to 830 kPa, and possibly about 20 to 620 kPa, while the partial pressure of hydrogen can be about 30 to 1100 kPa, and possibly about 65 to 700 kPa. Generally, the molar ratio of gaseous hydrogen to carbon monoxide, H2:CO, may be in the range of about 1:10 to 100:1 or more, and possibly about 1:1.4 to about 50:1.

[0048] Furthermore, as described above, the hydroformylation reaction method of the present invention can be carried out at a reaction temperature of approximately 50°C to approximately 145°C. However, hydroformylation reactions are typically carried out at reaction temperatures of approximately 60°C to approximately 120°C, or approximately 65°C to approximately 115°C.

[0049] Of course, the specific method by which the hydroformylation reaction is carried out and the specific hydroformylation reaction conditions used are not strictly important to the present invention and should be understood as being able to be broadly modified and adjusted to suit individual needs in order to produce specific desired aldehyde products.

[0050] Because internal cooling coils alone often lack sufficient heat removal capacity (limited heat transfer area per coil volume), external cooling loops (pump circulation of reactor contents via an external heat exchanger (cooler)) are typically used in high-exothermic hydroformylation reactions such as those involving low-carbon olefins (C2 to C5). In addition, internal cooling coils displace the volume of the internal reactor, increasing the size of the reactor for a given production rate. However, in some embodiments, at least one internal cooling coil is located inside the reactor, typically in the first reaction zone. In some embodiments, such an internal cooling coil can be added to an external cooling loop. In preferred embodiments, the liquid process fluid used to generate the jet (separately or in conjunction with a variation of a high-shear microbubble generator) passes through a heat exchanger (preferably before the microbubble generator) before being reintroduced into the same reaction zone. The flow of the cooled process fluid can be varied to ensure optimal temperature control of the reaction zone, for example, as taught in U.S. Patent No. 9,670,122 (particularly Figure 3).

[0051] Preferred examples of olefins that can be used as reactants in the present invention include ethylene, propylene, butene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 2-butene, 2-methylpropene, 2-pentene, 2-hexene, 2-heptene, 2-e Examples include tylhexene, 2-octene, styrene, 3-phenyl-1-propene, 1,4-hexadiene, 1,7-octadiene, 3-cyclohexyl-1-butene, allyl acetate, allyl butyrate, methyl methacrylate, vinyl methyl ether, vinyl ethyl ether, allyl ethyl ether, n-propyl-7-octenoate, 3-butenenitrile, 5-hexenamide, 4-methylstyrene, and 4-isopropylstyrene. Mixtures of isomers (e.g., butene raffinate) can also be used. The resulting aldehyde products may be hydrogenated and converted to corresponding alcohols that can be used as solvents or in the preparation of plasticizers, or subjected to other subsequent reactions such as aldol condensation to higher aldehydes, oxidation to corresponding acids, or esterification to produce corresponding acetate, propionic acid, or acrylic acid esters.

[0052] Olefin starting materials are introduced into the reactor by any convenient technique, either as a gas (optionally, together with the incoming synthesis gas feed), as a liquid in the reactor, or as part of a recirculation loop before entering the reactor. One particularly useful method is to introduce the olefin feed and the synthesis gas feed in very close proximity to each other by using a separate olefin spurger (described later) next to or below a jet or optional synthesis gas spurger.

[0053] To help explain the operation of some embodiments of the hydroformylation reaction method of the present invention, Figure 1 is referenced here. Figure 1 shows a non-limiting example of a cylindrical reactor 1 that can be used to carry out the hydroformylation reaction method according to one embodiment of the present invention. Reactor 1 contains a reaction fluid which is a mixture of olefin, hydrogen, carbon monoxide, a homogeneous catalyst, an aldehyde product, a solvent, and other components. The reactor has three reaction zones 1A, 1B, and 1C. A portion of the reaction fluid is removed from the first reaction zone 1A through an outlet 3 at the bottom of the reactor. At least a portion of the removed reaction fluid passes through two shear mixers 4 and, as shown in Figure 3a or Figure 3b, fresh or recirculated synthesis gas (with or without inert substances) is introduced to generate bubbles in the portion of the removed reaction fluid. The removed reaction fluid is returned to the first reaction zone 1A through two nozzles 5. The nozzles and their orientation will be described further below. The removed reaction fluid is returned to the first reaction zone 1A through nozzles 5 that form one or more liquid jets of the reaction fluid to be returned, which impart momentum and gas-liquid mixing to most of the reactor fluid. A shear mixer is described in U.S. Patent No. 5,845,993, which is incorporated herein by reference.

[0054] With respect to the reaction fluid removed from the bottom of reactor 1 via flow 2, the crude product and catalyst mixture can be removed from flow 2 via a product-catalyst separation zone (not shown). This flow 2 may also pass through a thermal removal process so that the returning process fluid is cooled to cool the reaction zone.

[0055] As used herein, the terms “shear mixer,” “high shear mixer,” “microbubble generator,” and “high shear microbubble generator” are interchangeable and refer to equipment capable of generating bubbles with an average size of 3,000 microns or less in a fluid. Key features and advantages of shear mixers that can be used in embodiments of the present invention are that they consist entirely of static piping components (e.g., no moving parts or mechanical seals, no maintenance required, no potential for leaks / failures), thus improving inherent safety, mechanical reliability, low environmental emissions, and plant uptime. Examples of shear mixers that can be used in embodiments of the present invention are described in U.S. Patent No. 5,845,993, incorporated herein by reference. Generally, a shear mixer includes a pressurized gas conduit or chamber in contact with a single (or more) turbulent liquid flow separated by a perforated surface. The gas enters the liquid flow through the perforations, driven by the shear stress generated by the liquid flow. Two typical embodiments of such a shear mixer are shown in Figure 3. For example, in one embodiment (Figure 3a), the shear mixer has an internal channel that carries a liquid flow (L). An outer concentric jacket is attached to this channel, which is connected to a pressurized gas inlet (G). A portion of the internal channel enclosed by the outer jacket is perforated by numerous punctures. These punctures are where the gas (G) from the outer jacket enters the liquid (L) flow in the internal channel in the form of a gas dispersion in the liquid, consisting of small bubbles. In this invention, the liquid (L) is at least a portion of the removed reaction fluid that is returned to the first reaction zone, and the gas (G) is the synthesis gas.

[0056] In some embodiments, a portion of the synthesis gas may be introduced into the first reaction zone via conventional sparging (as disclosed, for example, in International Publication No. 2018 / 236823), in addition to the synthesis gas introduced via a shear mixer. In other embodiments, the sole source of synthesis gas supplied to the first reaction zone is via a shear mixer.

[0057] In embodiments of the present invention, since bubbles are generated by a shear mixer, the mixing energy introduced into the first reaction zone without the use of conventional sparging differs from that described in International Publication No. 2018 / 236823. The momentum generated by the flow through the shear mixer needs to uniformly distribute the bubbles throughout the entire reaction fluid, starting from the nozzle exit. In some embodiments where conventional sparging is used, the majority of the momentum from the jet exiting the nozzle does not need to reach the bottom of the first reaction zone, but only needs to distribute the bubbles throughout the entire first reaction zone. To achieve suitable mixing and gas dispersion, there are several reactor and nozzle design considerations that need to be addressed, as further described below.

[0058] As shown in the following mixed energy density formula, the inventors have found that the mixed energy density (power supplied per unit volume) provided by the jet is 500 W / m³. 3 We have found that superior results are achieved when the energy exceeds a certain value. In the absence of such mixing energy, the turbulence of the reaction fluid is low (or zero), resulting in larger gas bubble sizes. Due to increased buoyancy and detachment from the liquid, these bubbles rise rapidly to the gas-liquid interface, reducing gas stagnation within the reactor. Generating and maintaining small bubbles is crucial for producing a uniform reaction fluid that provides better gas-liquid mixing, gas stagnation, and more reproducible reactor performance. Smaller bubbles result in maximum gas stagnation and maximize the mass transfer area between the bubbles and the liquid dissolving the synthesis gas (optimized gas volume / surface ratio). Conversely, very small bubbles can be trapped within the liquid streamlines near outlet nozzles (e.g., to external recirculation pumps / heat exchangers or at the reactor product outlet), which can adversely affect downstream equipment. Therefore, a key feature of this invention is the ability to consistently generate bubbles within an appropriate size range.

[0059] Referring again to Figure 1, the reaction fluid is removed from the bottom of the reactor 1 via outlet 3 and returned to the reactor via two or more nozzles 5, which are optionally terminated at a flow divider plate or limiting nozzles (described later). In some embodiments, the two or more nozzles 5 may be oriented in a symmetrical pair, a symmetrical triple configuration, or other symmetrical arrangement.

[0060] The nozzle 5 may be oriented to direct the liquid jet downward, upward, or both. In some embodiments, the nozzle may be oriented so that the liquid jet does not point toward the central longitudinal axis of the reactor 1 (for example, not toward the central axis of the reactor). Preferably, the liquid jet is not oriented strictly horizontally or strictly vertically, or directly toward the vertical axis or center of the reactor. The orientation of the nozzle will be further described below in relation to Figure 2.

[0061] In some embodiments, multiple sets of symmetrical nozzles can be arranged in different nozzle orientations (radial positions) and / or at different heights within the reactor 1. In some embodiments, various liquid feeds (e.g., liquid olefin feed, liquid catalyst flow from an upstream reactor, liquid catalyst flow from a product-catalyst separation zone, etc.) can be supplied to the reactor 1 via the shear mixer 4. In some embodiments, one or more of these feeds may be combined with the returned removed reaction fluid and supplied to the reactor 1 via at least one shear mixer. If the liquid feed is from an upstream reactor, some synthesis gas may be present, but this corresponds to a small amount of synthesis gas compared to the synthesis gas introduced by the shear mixer 4. In the embodiment shown in Figure 1, a fresh liquid olefin feed 6 is combined with the returned reaction fluid 7 and supplied to the reactor 1 via the shear mixer.

[0062] The removed reaction fluid that is returned exits each nozzle 5 as a jet. As used herein, the terms “jet,” “directed jet,” and “directed flow” are used interchangeably and are described in International Publication No. 2018 / 23623, except that the synthesis gas is supplied by one or more shear mixers rather than sparging. The jet may be the output or a separate flow of one or more shear mixers specifically designed to mix the first reaction zone (either separately from or in conjunction with the shear mixers).

[0063] The jet provides a downward backflow, counteracting the natural buoyancy of the bubbles and maintaining the entrainment of the bubbles in the liquid circulating throughout the backmix reactor, resulting in a more uniform distribution of synthesis gas bubbles throughout the backmix liquid phase. As the synthesis gas dissolves and reacts, the bubbles contract, which further helps maintain their distribution within the backmix liquid phase and facilitates good gas mass transfer into the liquid phase. This uniformly mixed liquid reaction fluid moves across permeable physical barriers, such as perforated partitions (described later), into the non-agitated reaction zone, so that in some embodiments, the reaction proceeds in a controlled manner without the need to supply external mixing energy.

[0064] The jet of reactant fluid being returned provides the reactant fluid with a mixing energy density to properly mix the reactants in the reactant fluid and promote the reaction.

[0065] In some embodiments, the jet provides sufficient mixing energy density so that a stirrer or other mechanical source of mixing energy is not required. The jet is given by the following formula:

[0066]

number

[0067] The flow rate of the reaction fluid through the shear mixer can also be important to ensure that adequate mixing energy is supplied to the first reaction zone. Therefore, in some embodiments, the flow rate of the reaction fluid through the shear mixer is as follows: q SM >525(μo / ρ o )P SM (In the formula, q SM This is the flow rate (m³) of the reaction fluid entering the shear mixer. 3 / s) and ρ o This is the density (kg / m³) of the reaction fluid before it enters the shear mixer. 3 ) and μ o P is the viscosity (Pa·s) of the reaction fluid before it enters the shear mixer. SM (q is the minimum wet perimeter of the cross-section of the liquid flow inside the shear mixer) is satisfied. The flow rate of the reaction fluid entering the shear mixer (q SM )(m 3 ( / s), density of the reaction fluid before it enters the shear mixer (ρ o )(kg / m 3 ), and the viscosity (μ) of the reaction fluid before it enters the shear mixer. o (Pa·s) can be measured using techniques known to those skilled in the art based on the teachings herein. Minimum wet perimeter (P) of the cross-section of the liquid flow inside the shear mixer. SM ) can be determined as follows: In the case of a conventional pipe transporting the reaction fluid through a shear mixer, P SM This is obtained by multiplying π by the inner diameter of the pipe (P SM =ID tube ). In some cases, an inner tube may also be present, and the reaction fluid may flow through an annular region between the outer wall of the inner tube and the inner wall of the outer tube. In this case, P SM This is obtained by multiplying π by the sum of the outer diameter of the inner tube and the inner diameter of the outer tube (P SM =π(OD inner tube +ID outer tube ))

[0068] In one embodiment, all jets are from a shear mixer. In another embodiment, some jets are solely for imparting mixing energy density, while others are from one or more shear mixers. In yet another embodiment, a multizone reactor has shear mixer jet loops in multiple reaction zones within the reactor, each jet loop recirculating fluid removed from the same zone from which it was removed. In yet another embodiment, a multizone reactor can be configured to remove reaction fluid from a first reaction zone and return the reaction fluid to a second reaction zone as a jet via a shear mixer. In a further embodiment, all zones within the reactor body have jets from a high shear mixer. In a preferred embodiment, the second reaction zone is selected from a bubble column reactor, a plug flow reactor, a piston flow reactor, a gas or bubble lift (tubular) reactor, a packed bed reactor, or a venturi reactor, rather than a backmix reactor. Examples of non-reverse-mixing reactors include U.S. Patents No. 5,367,106, No. 5,105,018, No. 7,405,329, and No. 8,143,468.

[0069] The position and orientation of the nozzles within the reactor are important, especially when two or more nozzles are provided. For example, arranging two nozzles so that the jets exiting them are directly oriented toward each other should generally be avoided. Figure 2 is a schematic side view and two top views of a cylindrical reactor 100 to show the position and orientation of nozzle 105 according to some embodiments of the present invention. Figure 2 also shows a donut baffle 110 (described further below) located below nozzle 105 within the reactor 100. Alpha (α) is the angle of the nozzle with respect to the horizontal plane. In some embodiments, when the horizontal angle is 0°, α may be in the range between 75° (upward angle) and -75° (downward angle). In some embodiments, when the horizontal angle is 0°, α may be in the range between 45° (upward angle) and -60° (downward angle). Beta (β) is the angle at which the nozzle is oriented to the left or right with respect to the centerline. In some embodiments, if the orientation of the nozzles is 0°, with the nozzles facing straight across the reactor, then β is approximately 5° to 90° (the nozzles are oriented clockwise when viewed from above the reactor) or -5° to -90° (the nozzles are oriented counterclockwise when viewed from above the reactor). β should be -5° to 5° if phi (φ) is greater than 0°. Phi (φ) is the distance the nozzles are offset from the reactor centerline when viewed from above. φ should be 50% or less of the cross-sectional diameter of the reactor. In some embodiments where at least two nozzles return the removed reaction fluid to the reactor, each nozzle is oriented such that the angle of the nozzle with respect to the horizontal plane (alpha (α)) is +75° to -75°, and alpha (α), the angle of the nozzle with respect to a vertical plane passing through the center of the reactor (beta (β)), and the distance from the vertical plane passing through the center of the reactor (phi (φ)) when beta is zero are all non-zero.

[0070] In some embodiments, the flow of the returning reaction fluid is not a single line, but it should be understood that the majority of the reaction fluid returning to the reactor through a single nozzle is within a relatively narrow range of α and β values. Where the terms “vertical” and “horizontal” are used for the purposes of this application in relation to the flow of the returning reaction fluid in a fluid splitter, those terms may be understood in terms of angles α and β, respectively. That is, a “vertical flow” or “vertical jet” is oriented upward and / or downward with a non-zero α and essentially zero β. A “horizontal flow” or “horizontal jet” is oriented leftward and / or rightward with an essentially zero α and a non-zero β. The term “directed flow” generally refers to a flow where both α and β are non-zero. A “directed flow” may include a flow from a shear mixer, or other flows that return to but do not pass through a shear mixer.

[0071] Referring further to Figure 2, delta (δ) is the distance the nozzle protrudes from the reactor wall into the reactor. In some embodiments, δ is less than 50% of the reactor diameter. In some embodiments, δ is 50% or less of the radius of the cylindrical reactor. In some embodiments, δ is at least 10% of the radius of the cylindrical reactor. In some embodiments, δ is 10% to 45% of the radius of the cylindrical reactor. In some embodiments, the ends of the flow dividers can be approximately coplanar with the reactor wall such that δ is approximately 0% of the radius of the cylindrical reactor.

[0072] In some embodiments, additional sets of nozzles can be provided at the same or different heights or at different angles (α and / or β), as shown in Figure 2. Figure 4 is a series of diagrams showing different positions of nozzles 205 within reactor 200, different positions of one or more donut baffles 210 relative to the jets (not referenced but represented by arrows exiting the ports of nozzles 205), and angles of the jets exiting nozzles 205, according to some embodiments of the present invention. A shear mixer 215 is also shown, but is not referenced in the figures of Figure 4.

[0073] Phi (ψ) is the distance to which the nozzle tip is located (as a percentage of the reaction fluid filling height). As used herein, “reaction fluid filling height” refers to the height of the liquid in the reactor from the bottom of the reactor. In embodiments where the reactor has headspace in the bottom portion, as shown in Figure 2, all heights referred to as measured from the bottom of the reactor are measured from the tangent 102 across the reactor directly above the headspace. If the reactor has a flat bottom, as further shown in Figure 2, all heights referred to as measured from the bottom of the reactor are measured from the physical bottom. ψ is less than 100% of the reaction fluid filling height. In some embodiments, ψ is less than 90% of the reaction fluid filling height. In some embodiments, ψ is 75% to 80% of the reaction fluid filling height.

[0074] Each shear mixer is designed to introduce synthesis gas bubbles into the removed reaction fluid. While not bound by theory, the thorough mixing with high liquid velocity and small initial bubble size provided by embodiments of the present invention minimizes synthesis gas bubble coalescence, promotes bubble size reduction by shear, and ensures uniform gas-liquid distribution and temperature throughout the reaction zone. The natural buoyancy of small synthesis gas bubbles is offset by the viscosity of the liquid and the turbulence of the liquid mass. Similarly, if the non-agitated reaction zone is above the first reaction zone, the natural buoyancy that causes bubbles to rise and over permeable physical barriers such as a grid or perforated plate separating the two zones is offset by the viscosity of the liquid and the turbulence of the liquid mass. Excessively large bubbles rise too rapidly, resulting in less gas stagnation and a non-uniform distribution. In some embodiments, the average size of bubbles produced by the shear mixer may range from 10 nanometers to 3,000 microns. In some embodiments, the average size of bubbles produced by the shear mixer is 3 to 3,000 microns. In some embodiments, the average size of bubbles produced by the shear mixer is 30 to 3,000 microns. In some embodiments, the average size of bubbles produced by the shear mixer is 100 to 800 microns.

[0075] The method by which the reaction fluid is returned affects the effectiveness of the mixing energy provided. In some embodiments, the reaction fluid may be returned using piping having one or more flow divider plates installed at the end of the piping and inserted and attached to the reactor's recirculation return nozzle. In some embodiments, the reaction fluid may be returned using a nozzle or flow orifice located at the end of the piping, as further described below, and inserted and attached to the reactor's recirculation return nozzle. In each case, the velocity of the resulting liquid jet is a function of the flow area of ​​the nozzle or orifice, or the flow area created between the flow divider plate and the inner wall of the piping, and the mass flow rate and density of the reaction fluid being returned. The combination of flow area and flow velocity creates a jet of reaction fluid in the reactor, which imparts momentum and causes gas-liquid and liquid-liquid mixing of the bulk fluid in the reactor. Furthermore, the returned reaction fluid is divided and directed in multiple directions.

[0076] The term “flow divider” as used herein encompasses both nozzles and flow divider plates located within the reactor recirculation return pipe. In either case, the flow divider directs the flow of the returning reaction fluid. As further described below, in some embodiments, the flow divider directs the flow of the returning reaction fluid horizontally. In some embodiments, the flow divider directs the flow of the returning reaction fluid vertically. In some embodiments, the flow divider directs the flow of the returning reaction fluid both horizontally and vertically. A flow divider including a flow divider plate located at the end of the pipe is described in further detail in International Publication No. 2018 / 236823, which is incorporated herein by reference.

[0077] In some embodiments, horizontal donut baffles above or below the nozzle are used to reduce the flow or channeling effect within the reactor from the jet. A donut baffle is a flat ring plate fixed to the reactor wall, having a central opening that functions to divert channeling flow along the reactor wall. Non-limiting examples of the arrangement of such horizontal donut baffles are shown in Figures 1 (reference no. 14), 2 (reference no. 110), and 4 (reference no. 210). As shown in Figure 2, the donut baffle 110 extends from the reactor wall by a distance (γ). In some embodiments, the donut baffle extends from the reactor wall by a distance (γ) which is 5% to 25% of the reactor diameter. In some embodiments, the vertical position of the donut baffle within the reactor may also be important. As shown in Figure 2, the donut baffle 110 is positioned at a specific height (λ) from the bottom of the reactor. In some embodiments, the donut baffles may be positioned at a height (λ) from the bottom of the reactor, which is 90% or less of the reaction fluid filling height. Other techniques may be used to minimize the possibility of flow or channeling effects from the reaction fluid entering the reactor as a jet (see, for example, the positions of donut baffle 14 in Figure 1 and donut baffle 210 in Figure 4).

[0078] In some embodiments, such as the embodiment shown in Figure 1, the reaction fluid passes from a first reaction zone through a product outlet nozzle 3 at the bottom of the reactor. In such embodiments, the reactor may include a gas entrainment prevention means 8 located within the bottom volume of the reactor. Such means may be in the form of an entrainment separator, a conical condenser, one or more perforated plates, or a packed bed. A packed bed 8 is shown in Figure 1. Such a gas entrainment means 8 is particularly desirable when the jet is inclined downward, but may not be necessary if the recirculation pump can tolerate small entrained gas bubbles.

[0079] In some embodiments, when a single reactor includes multiple reaction zones, perforated partition plates can be placed between the reaction zones. For example, as shown in Figure 1, the reaction fluid from the first reaction zone 1A passes over the perforated partition plate 10 into the second reaction zone 1B. The perforated partition plate 10 can help to ensure that the reaction fluid rising into the second reaction zone 1B is uniform and that a substantial amount of synthesis gas is included for the continuation of the reaction. This is particularly desirable for bubble reactors, plug flow reactors, and packed column reactors, as the reactants are highly homogeneous and diffusion is not restricted.

[0080] In the embodiment shown in Figure 1, the second perforated partition plate 12 separates the second reaction zone 1B from the third reaction zone 1C.

[0081] For effectiveness, the perforations in a perforated partition plate should be uniformly distributed to evenly distribute the rising fluid across the cross-section of the reactor. In plug-flow reactors or packed-bed column reactors, the perforations should direct the flow so that each tube or column obtains the same fluid flow. The design of perforated partition plates or trays is well known in the art. A typical perforated partition plate / tray has a porosity of 15–40% (preferably 20–30%), and the perforations should be uniformly distributed across the entire surface. The perforations may be uniform, or they may have different diameters of equivalent hole diameters, typically ranging from 1 / 8 inch to 2 inches. The holes may be circular, square, slotted, or other shapes, and may have additional features (e.g., countersunk holes, raised holes), but should not accumulate large amounts of gas beneath the perforated partition plate. In some embodiments, wire mesh or similar rigidly supported material may be used as an alternative to the perforated partition plate.

[0082] A vertical baffle may be attached to the inner wall of the first reaction zone to shear and lift radial streamlines from the container wall, thereby providing further mixing and minimizing rotational flow.

[0083] Returning to Figure 1, the final reaction zone 1C contains a reactor outlet 9 for transporting the reaction fluid to the next reactor or product-catalyst separation zone (not shown).

[0084] In addition, in embodiments where multiple reactors are arranged in series, an optional gas purge flow 14 from reactor 1 may be discharged, spread, and sent to a plant fuel gas header or another reactor. Analysis of this purge flow 14 can provide a convenient means of measuring the CO partial pressure in the upper reaction zone for reaction control.

[0085] Although not shown in Figure 1, the system also includes other standard equipment components that are readily recognizable and implementable by those skilled in the art, such as pumps, heat exchangers, cooling coils, valves, level sensors, temperature sensors, and pressure sensors.

[0086] In some embodiments, the removed reaction fluid returned to the first reaction zone through one or more nozzles can provide at least 50% of the total mixed energy density to the first reaction zone. In some embodiments, the removed reaction fluid returned to the first reaction zone through one or more nozzles can provide at least 85% of the total mixed energy density to the first reaction zone. In some embodiments, the returned reaction fluid can provide substantially all or 100% of the total mixed energy density to the first reaction zone. It should be understood that the total mixed energy density includes the mixed energy provided by the operating agitator (if present), the jet of the returned reaction fluid, or other sources of mixed energy density, but does not include any minute mixed energy density provided by introducing synthesis gas, olefins, or other reactants into the reactor. For example, there is some minute mixed energy density provided by the hydraulic flow of liquid reaction fluid passing from the first reaction zone through subsequent reaction zones (e.g., through baffles, if present), but this is also not included. In embodiments where the liquid jet generated by the returning reaction fluid provides substantially all or 100% of the mixing energy density, the reactor either does not include a stirrer or includes a non-operating stirrer.

[0087] If a stirrer is present and operating, the contribution of the mixing energy density from the stirrer is given by the following equation: P=N pg ×ρN 3 D 5 (In the formula, N pg This can be calculated using the impeller's gassed power number, ρ being the density of the reaction fluid, N being the rotational speed of the agitator (rev / s), and D being the diameter of the impeller.

[0088] Surprisingly, it has been found that by using the shear mixing apparatus described herein, it is possible to enable the operation of a hydroformylation reactor without operating a stirrer, while providing the same level of gas-liquid and liquid-liquid mixing of the reaction fluid. By increasing the flow rate of the reaction fluid being returned, stable operation can be enabled without operating a stirrer, and excellent gas dispersion into the liquefied reaction fluid can be facilitated. Some embodiments of the present invention have the advantage of enabling continuous operation of a reactor with a stirrer until the unit can be shut down for repair, thus avoiding unplanned production losses, by providing adequate mixing within the reactor without using a stirrer, in the event of problems with the stirrer motor, stirrer seal, stirrer shaft / impeller, steady bearing or similar stirrer-related issues, and thus avoiding unplanned production losses. In other words, in retrofits, some embodiments of the present invention may enable repairs without operating the existing stirrer and / or while the reactor continues to operate. In the case of new reactors, some embodiments of the present invention can advantageously eliminate the cost of a stirrer, as well as the need for stirrer seals and steady bearings that require maintenance / replacement, and can eliminate seal leaks.

[0089] Herein, some embodiments of the present invention will be described in detail in the following examples. [Examples]

[0090] In this embodiment, the performance of three designs was evaluated using a computational fluid dynamics ("CFD") tool. Comparative Example A is a representative example of the prior art using a mechanical agitator. Examples 1 and 2 of the present invention represent embodiments of the present invention that utilize a shear mixer without a mechanical agitator. The objective is to demonstrate the equivalence and / or improvement in performance criteria of the agitator-free designs of the present invention (Examples 1 and 2 of the present invention) to a conventional mechanically agitated design (Comparative Example A). In this embodiment, CFD was used to evaluate performance with respect to (a) mixing efficiency (i.e., mixing time), (b) gas dispersion (i.e., gas volume fraction and overall gas stagnation uniformity), (c) degassing (i.e., volume %) of gas in the bottom recirculation line, and (d) mass transfer (i.e., mean mass transfer coefficient (KLa) in the first reaction zone).

[0091] The importance of synthesis gas dispersion For several reasons, it is important to have highly dispersed and well-dispersed synthesis gas within the reactor. Only synthesis gas dispersed and dissolved in the reaction fluid can react. Therefore, synthesis gas introduced into the reactor is rapidly dispersed and dissolved in the reaction fluid instead of rising as bubbles at the gas-liquid interface, leaving the reactor's vapor space and becoming unusable for the reaction. Furthermore, any volume in the reactor where synthesis gas is not dispersed or dissolved does not contribute to the reaction or the reactor's productivity due to a lack of reactants. Thus, a highly dispersed (high gas stagnation or gas fraction) and homogeneous gas mixture is the most desirable outcome.

[0092] Methods for evaluating effectiveness in CFD To evaluate the mixing characteristics of the present invention, it is useful to examine the gas distribution from CFD modeling to identify both the uniformity of the gas distribution and the range of the gas load. Commercial experience with well-agitated CSTR reactors shows that the gas load values ​​range from 5 to 12%. While CFD modeling programs can be used to predict the overall or average gas load values ​​for the entire reactor, this may underestimate the local effects of areas with high or low gas loads and short residence times (e.g., piping inlets / outlets, nearby agitator impellers, etc.).

[0093] Effectiveness of mixing: Mixing time θ mix • For a well-mixed system, the mixing time θ mix Typically, this corresponds to the average liquid residence time θ. res It should be less than 10% to 20%. (See below: Paul, EL, VAAtiemo-Obeng and SMKresta, eds. 2004. Handbook of Industrial Mixing: Science and Practice. John Wiley & Sons, Inc.) • In this CFD simulation, for the first reaction zone in each embodiment, the mixing time θ mix I evaluated it. • A well-known tracer injection method was implemented. The simulation was first run without tracer. Once a steady state was reached, tracer was continuously injected into the fresh feed inlet, and its concentration was tracked in the first reaction zone. At each simulation time step, the coefficient of variation (CoV) was evaluated as the volume standard deviation of the concentration relative to its volume mean. • Mixing time was defined as the flow time at which CoV reached 5%.

[0094] Gas dispersion: Gas volume fraction and overall uniformity of gas stagnation To evaluate the mixing characteristics of the present invention, it is convenient to investigate the gas distribution from CFD modeling to determine both the uniformity of the gas distribution and the degree of gas loading. • Commercial experience with well-agitated CSTR reactors indicates that the gas load is in the range of 5–12%.

[0095] Degassing: Percentage of gas volume in the bottom recirculation line The bottom outlet of the reaction vessel typically leads to a centrifugal pump used to recirculate the fluid. • If the synthesis gas bubbles are small enough, they may be carried into the outlet. If the entrainment is large enough, the presence of the gas may damage the pump. • For safe pump operation, it is essential to maintain the gas volume fraction in the bottom recirculation line between less than 3% and 5%. • In CFD modeling, this volume fraction was tracked, and this value was reported for each case.

[0096] Mass transfer: The overall effectiveness of gas-liquid system reactions, such as hydroformylation systems, is based on the rate at which the synthesis gas components (CO and H2) move into the liquid phase. The mass transfer rate of synthesis gas into the liquid phase in any given reaction zone is directly proportional to the average value of the mass transfer coefficient (kLa) in that reaction zone. In this embodiment, CFD modeling was used to directly obtain the average value of the mass transfer coefficient (KLa) in the first reaction zone. For this purpose, a method well described in the literature was used. See Gimbun, Reilly and Nagy, "Modelling of mass transfer in gas-liquid stirred tanks agitated by Rushton turbine and CD-6 impeller: A scale-up study," Chemical Engineering Research and Design 87 (2009) 437-451. To ensure equivalent performance between two reactors performing the same gas-liquid reaction under identical operating and supply conditions, the total volume KLa values ​​should be equivalent. Generally, a higher KLa value is preferable.

[0097] Operating conditions and parameters For each of the examples, the following operating conditions and parameters were used. The operating pressure was approximately 15 bar (absolute pressure). At this pressure, the density of liquid propylene was approximately 775 kg / m³. 3 The density of synthesis gas is approximately 9.06 kg / m³. 3 The supply flow rates of synthesis gas and liquid propylene for each example are also shown in Table 1. The viscosity of liquid propylene is 3.8 × 10⁻⁶. -4 The viscosity of synthesis gas in Pas is 1.8 × 10⁻⁶. -5The pressure is assumed to be Pa.s. The gas-liquid surface tension between synthesis gas and liquid propylene is assumed to be 18 dynes / cm (0.018 N / m), in line with the typical value for similar organic substances.

[0098] Comparative example A The original reactor was a mechanically agitated tank with a diameter of 5.5 meters and a cylindrical section height of 10 meters, capped at the top and bottom by two identical 2:1 semi-ellipsoidal heads. The tank's volume was vertically divided into three reaction zones (numbered 1-3 from bottom to top) by two horizontal baffles. The baffles were identical stainless steel plates with the same diameter as the tank and a single central orifice with a diameter of 0.7 meters. In addition, the tank was fitted with four identical vertical baffles positioned at 90° intervals along the reactor wall.

[0099] Synthesis gas was introduced using two identical ring spargers located in the first reaction zone (0.2 m above the lower tangent) and the second reaction zone (0.2 m above the lower horizontal baffle). The agitator is a shaft fitted with three impellers: a standard gas distribution turbine in the bottom compartment and two hydrofoils in the second and third reaction zones. The agitator operates at 89 rpm.

[0100] A degassing ring, concentric with the reactor body, was attached to a bottom dish-shaped head surrounding the bottom recirculation nozzle.

[0101] Table 1 summarizes the reactor dimensions and flow rates.

[0102] [Table 1]

[0103] Example 1 of the present invention The reactor dimensions (diameter and L / D) are the same as those of Comparative Example A. There is no stirrer; instead, mixing and gas dispersion are performed using a recirculation jet entering the first reaction zone. In addition, the following other modifications were made compared to Comparative Example A. 1. The liquid recirculation flow rate was increased 16-fold. 2. Gas Introduction and Bubble Size: The sparging was removed. The synthesis gas was then introduced directly into the recirculation flow using two shear mixers, each located just upstream of the recirculation inlet nozzle. These shear mixers were designed to introduce the gas into the reactor with an average bubble diameter of 300 microns. Details of the shear mixers are described in the final section on shear mixers in the Examples section. 3. Horizontal baffles: The horizontal baffles in the design of Comparative Example A were replaced with perforated stainless steel plates. These plates have a 20% opening area to allow the two-phase (gas-liquid) reaction fluid to pass vertically upward from the bottom compartment to the middle compartment. 4. Nozzles: The wedge inserts were removed from the recirculation inlet nozzles. Each recirculation inlet nozzle has a curved section at its end, thereby, a. The gas-liquid jet enters at a vertical angle of 20 degrees (α) (downward along the central axis of the reactor) and an azimuth angle of 30 degrees (β) (counterclockwise around the central axis of the reactor). b. Reduce the nozzle diameter to a nominal size of 7 inches at the end using a standard conical reducer (12 inches x 7 inches). c. The nozzle opening into which the two-phase jet enters the first reaction zone was positioned 2.52 m above the lower tangent of the reactor and at a height (δ) of 0.45 m radially inward from the inner wall of the reaction vessel. 5. Internal degassing: The degassing ring was removed. A filled bed with a void ratio of 36% and a total height of 1.375 m was installed in its place. 6. Internal: To prevent gas channeling to the second reaction zone, a donut baffle was added to the first reaction zone. A donut baffle with a width of 0.59 m was placed 2 m above the lower tangent. 7. Bottom recirculation nozzle: The nozzle size was increased from the original 16 inches to 22 inches to reduce the rate of liquid exiting the reactor.

[0104] Table 2 summarizes the various dimensions and other parameters of Example 1 of the present invention.

[0105] [Table 2]

[0106] As mentioned above, Figure 2 defines various parameters for characterizing the orientation and position of the nozzles in the reactor. Table 3 provides the values ​​of these parameters for Examples 1 and 2 of the present invention.

[0107] [Table 3]

[0108] Example 2 of the present invention Embodiment 2 of the present invention is the same as Embodiment 1 of the present invention, except for the following changes. 1. Internal degassing: The fill bed was removed. In its place, a laminate of three horizontal perforated boards was used. The perforation area fractions were 30% (top board), 20% (middle board), and 15% (bottom board). The gap between the boards was 0.25 m.

[0109] result The results of the CFD modeling are shown in Tables 4A and 4B.

[0110] [Table 4]

[0111] [Table 5]

[0112] As shown in Table 4, Examples 1 and 2 of the present invention have comparable performance to Comparative Example A (e.g., mixing time, kLa, and volume %) of gas in the recirculation line, despite not having a mechanical stirrer. Examples 1 and 2 of the present invention also have significantly lower power consumption (see P / V).

[0113] Figures 5 and 6 show color-coded gas volume fractions and KLa color-coded diagrams for Comparative Example A and Examples 1 and 2 of the present invention. As shown in Figure 5, the examples of the present invention have a very uniform gas volume fraction.

[0114] shear mixing device The shear mixing apparatus used in Examples 1 and 2 of the present invention is of the type described in U.S. Patent No. 5,845,993. Each apparatus consists of a pressurized gas conduit or chamber in contact with one (or more) turbulent liquid flows separated by a perforated surface. The gas enters the liquid flow through the perforations, driven by the shear stress generated by the liquid flow.

[0115] In Examples 1 and 2 of the present invention, as shown in Figure 3a, the shear mixer consists of an internal channel that carries a liquid flow. An outer concentric jacket connected to a pressurized gas inlet is attached to this internal channel. A portion of the internal channel enclosed by the outer jacket is perforated by numerous punctures. These punctures are where the gas from the outer jacket enters the liquid flow in the internal channel in the form of a gas dispersion in the liquid, consisting of small bubbles. In Examples 1 and 2 of the present invention, the liquid is the reaction fluid removed from the reactor, and the gas is the synthesis gas.

[0116] The shear mixer was configured to provide an average bubble size of 300 microns. The dimensions and flow rate of the shear mixer used to achieve this average bubble size are shown in Table 5.

[0117] [Table 6]

Claims

1. A method for hydroformylation, (a) Providing a reaction fluid by contacting an olefin, hydrogen, and carbon monoxide in the presence of a homogeneous catalyst in a reactor, wherein the reactor includes one or more reaction zones, (b) Removing a portion of the reaction fluid from the first reaction zone, (c) passing at least a portion of the removed reaction fluid through a shear mixer to generate bubbles in the portion of the removed reaction fluid, wherein at least a portion of the hydrogen and carbon monoxide supplied to the reactor is introduced through the shear mixer, (d) Returning the removed reaction fluid to the first reaction zone through one or more nozzles, wherein the returned reaction fluid exiting each nozzle is in the form of a jet. Includes, The mixing energy density supplied to the reactor by the jet is given by the following formula: [Math 1] (In the formula, V is the volume of the reaction fluid in the first reaction zone (m³) ３ ) where N is the total number of jets returned to the first reaction zone such that each jet is uniquely identified using a natural number from i=1 to i=N (in increments of 1), ρ ｉ This is the average density (kg / m³) of the reaction fluid at the nozzle port as it is returned to the first reaction zone through the i-th jet. ３ ) and Q ｉ This is the volumetric flow rate (m) of the reaction fluid that is returned to the first reaction zone through the i-th jet. ３ / s) and A ｉ This is the cross-sectional area (m²) of the i-th nozzle through which the reaction fluid flows, at the position where the reaction fluid exits the nozzle and enters the first reaction zone. ２ ) Satisfying method.

2. The flow rate of the reaction fluid passing through the shear mixing device is as follows: q ＳＭ >525(μ) ｏ / r ｏ )P ＳＭ (In the formula, q ＳＭ The flow rate (m) of the reaction fluid entering the shear mixing device is ３ / s) and ρ ｏ The density of the reaction fluid before it enters the shear mixing apparatus (kg / m³) ３ ) and μ ｏ This is the viscosity (Pa·s) of the reaction fluid before it enters the shear mixing apparatus, and P ＳＭ (This is the minimum wet perimeter of the cross-section of the liquid flow inside the shear mixing apparatus.) The method according to claim 1, which satisfies the requirements of claim 1.

3. The method according to claim 1 or 2, wherein at least two nozzles return the removed reaction fluid to the reactor, and each nozzle is oriented such that the angle of the nozzle with respect to the horizontal plane (alpha) is between +75° and -75°, and alpha, the angle of the nozzle with respect to a vertical plane passing through the center of the reactor (beta), and the distance from the vertical plane passing through the center of the reactor when beta is zero (phi) are all non-zero.

4. The method according to any one of claims 1 to 3, wherein hydrogen and carbon monoxide are provided as synthesis gas, and at least 20% of the synthesis gas provided to the first reaction zone passes through the shear mixing apparatus before entering the first reaction zone.

5. The method according to any one of claims 1 to 4, wherein hydrogen and carbon monoxide are provided as synthesis gas, and at least a portion of the synthesis gas is introduced into the cylindrical reactor through a spurger at a height of less than 50% of the reaction fluid filling height of the first reaction zone.

6. The method according to any one of claims 1 to 5, wherein the reactor includes a horizontally oriented ring baffle attached to the inner wall of the reactor, the ring baffle is positioned at a height of less than 90% of the height of the liquid reaction fluid in the first reaction zone, and the solid portion of the ring baffle extends to 5 to 30% of the diameter of the reactor.

7. The method according to any one of claims 1 to 6, further comprising a stirrer disposed within the cylindrical reactor.

8. The method according to claim 7, wherein the agitator and the returned reaction fluid provide a mixing energy density within the cylindrical reactor.

9. The method according to claim 7, wherein the agitator does not operate.

10. The method according to any one of claims 1 to 9, wherein the reactor is oriented vertically.

11. The method according to any one of claims 1 to 10, wherein the reactor further includes a second reaction zone, and the reaction fluid flows from the first reaction zone to the second reaction zone without piping.

12. The method according to claim 11, wherein the first reaction zone and the second reaction zone are separated by a perforated plate.

13. The method according to claim 11 or 12, wherein the reactor further includes a third reaction zone, and the reaction fluid flows from the second reaction zone to the third reaction zone without piping.

14. The method according to claim 13, wherein the second reaction zone and the third reaction zone are separated by a perforated plate.

15. The method according to any one of claims 1 to 14, wherein the average bubble size of the bubbles generated by the shear mixing device is 10 nanometers to 3,000 microns.

16. The method according to any one of claims 1 to 15, wherein the reactor includes a product outlet nozzle located in the lower part of the reactor, and the reactor includes means for preventing gas encompassion, located within the bottom volume of the reactor.

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