Catalyst for dehydration of hydroxypropionic acid and derivative thereof and method for producing same

Abstract

The present invention relates to a catalyst for dehydration of hydroxypropionic acid and a derivative thereof, and a method for producing same. A catalyst according to an embodiment of the present invention has very excellent life characteristics while exhibiting a high reaction yield and selectivity.

Description

Hydroxypropionic acid and its derivatives dehydration reaction catalyst and method for producing the same

[0001] The present invention relates to a dehydration reaction catalyst for hydroxypropionic acid and its derivatives and a method for producing the same.

[0002] Cross-citation with related applications

[0003] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0081445, filed June 23, 2023, the entire contents of which are incorporated herein by reference.

[0004]

[0005] Acrylic acid is typically synthesized through a two-step oxidation reaction of propylene, a petroleum-derived raw material. However, with the rapid rise in crude oil prices and concerns about future depletion, research is being conducted to obtain unsaturated carboxylic acids, such as acrylic acid, from biomass-based feedstocks.

[0006] Lactic acid can be mass-produced from starch through fermentation, and acrylic acid can be produced through dehydration of lactic acid. Metal phosphate, metal sulfate, or zeolite catalysts are commonly used for lactic acid dehydration. Among these, metal phosphate is being extensively studied, but its low acrylic acid yield is a problem.

[0007] Specifically, international publication WO2011 / 052178 discloses hydroxyapatite (Ca 10 (PO4)6(OH)2) or Sr 10 A synthetic method has been proposed to synthesize unsaturated carboxylic acids or their derivatives by dehydration reaction from hydroxycarboxylic acids or their derivatives using (PO4)6(OH)2 as a catalyst. However, when acrylic acid is synthesized from lactic acid using hydroxyapatite, the yield of acrylic acid is about 50-70%, and when Ca in hydroxyapatite is replaced with Sr, the yield of acrylic acid is about 50-70%. 10In the case of (PO4)6(OH)2, the yield of acrylic acid is even lower, at about 30%.

[0008] Accordingly, there is a need for the development of a manufacturing method and catalyst capable of synthesizing unsaturated carboxylic acids such as acrylic acid or their esters in high yield.

[0009]

[0010] The present specification seeks to provide a dehydration reaction catalyst for hydroxypropionic acid and its derivatives.

[0011] In addition, the present specification provides a method for producing a dehydration reaction catalyst for hydroxypropionic acid and its derivatives.

[0012]

[0013] The present disclosure provides a hydroxypropionic acid and derivative dehydration catalyst comprising a molded body in which hydroxyapatite primary particles are aggregated, wherein the primary particles have a volume average particle diameter of 15 to 150 μm; and a P value expressed by the following mathematical formula 1 is 3.5 to 19.

[0014] [Mathematical Formula 1]

[0015] P=A*B / C

[0016] In the above mathematical expression 1, A is the volume average particle size (㎛) of the powder, B is the crushing strength (N), and C is the specific surface area (m 2 / g) is the value.

[0017]

[0018] In one embodiment, the particle size of the primary particles may be about 25 to about 100 μm.

[0019]

[0020] In one example, the hydroxypropionic acid and its derivatives dehydration reaction catalyst may have an alkali metal content of about 3 wt% to about 8 wt%.

[0021]

[0022] In one example, the alkali metal may be sodium or potassium.

[0023]

[0024] As an example, the apparent density value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst is about 0.8 to about 1.0 g / cm 3 It could be.

[0025]

[0026] According to one example, the crushing strength value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst may be from about 6 to about 20 N.

[0027]

[0028] According to an example, the specific surface area value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst is about 50 to 90 m 2 / g may be.

[0029]

[0030] Meanwhile, the present disclosure provides a method for producing a hydroxypropionic acid and derivative dehydration reaction catalyst, comprising the steps of: preparing a slurry by adding 1 to 50 parts by weight of a binder to 100 parts by weight of hydroxyapatite; forming the slurry to produce a molded body; and drying the molded body.

[0031]

[0032] In one example, the binder may include 0.1 to 10 parts by weight of isopropyl alcohol per 100 parts by weight of hydroxyapatite.

[0033]

[0034] Meanwhile, the present disclosure provides a method for producing acrylic acid, comprising a step of subjecting a hydroxycarboxylic acid or a derivative thereof to a dehydration reaction in the presence of the aforementioned catalyst.

[0035]

[0036] In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

[0037] Additionally, the terms used herein are merely used to describe exemplary embodiments and are not intended to limit the present invention.

[0038] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0039] In this specification, the terms “comprise,” “include,” or “have” are intended to describe a feature, number, step, component, or combination thereof implemented, but do not exclude the possibility of one or more other features, numbers, steps, components, combinations, or additions thereof.

[0040] Additionally, in this specification, when each layer or element is referred to as being formed “on” or “over” each layer or element, it means that each layer or element is formed directly on each layer or element, or that other layers or elements may be additionally formed between each layer, on the object, or on the substrate.

[0041] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this does not limit the invention to a specific disclosed form, but rather encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0042]

[0043] In this specification, hydroxypropionic acid derivatives refers to a group of compounds encompassing all of hydroxypropionic acid and its derivatives, which are carboxylic acids having three carbon atoms in the main chain and one of which is substituted with a hydroxy group.

[0044] In addition, the dehydration reaction of hydroxypropionic acid and its derivatives refers to a reaction in which the hydrogen bonded to the hydroxy group and the carbon next to it in the compound is removed (elimination), thereby forming a carbon-carbon unsaturated double bond.

[0045]

[0046] Hereinafter, the present invention will be described in detail.

[0047]

[0048] According to one aspect of the invention, a hydroxypropionic acid and derivative dehydration catalyst is provided, which comprises a molded body in which hydroxyapatite primary particles are aggregated, the volume average particle diameter of the primary particles being 15 to 150 μm; and the P value represented by the following mathematical formula 1 being 3.5 to 19.

[0049] [Mathematical Formula 1]

[0050] P=A*B / C

[0051] In the above mathematical expression 1, A is the volume average particle size (㎛) of the powder, B is the crushing strength (N), and C is the specific surface area (m 2 / g) is the value.

[0052]

[0053] Apatite compounds are compounds that have an apatite structure, but usually contain calcium and phosphorus, Ca A (PO4) B -It refers to a compound of the calcium phosphate series represented by a chemical formula in the form of -X.

[0054] Among these, hydroxyapatite refers to a compound in which X in the above chemical formula is a hydroxy group, and such hydroxyapatite compound can be used as a catalyst for the dehydration reaction of hydroxypropionic acid and its derivatives for producing unsaturated carboxylic acids due to its unique structure and the presence of acid sites.

[0055] However, when these calcium phosphate series compounds are used as general hydroxyapatite single-phase catalysts, there are problems such as low yield in the dehydration reaction, and in particular, a very short lifespan, which results in low processability, such as a significant decrease in yield as the reaction time elapses.

[0056]

[0057] The inventors of the present invention have discovered that, in a method for producing acrylic acid or the like through a dehydration reaction of hydroxypropionic acid and its derivatives using hydroxyapatite as a catalyst, when hydroxyapatite powder is molded and the molded body is used as a catalyst, if the particle size of the hydroxyapatite powder used for molding is controlled within a certain range, a catalyst having a high reaction yield and selectivity as well as excellent life characteristics can be provided, and thus the present invention has been completed.

[0058]

[0059] According to one embodiment of the invention, a hydroxypropionic acid and derivative dehydration catalyst is provided, which comprises a molded body in which hydroxyapatite primary particles are aggregated, wherein the volume average particle diameter of the primary particles is 15 to 150 μm, and the P value represented by the following mathematical formula 1 is 3.5 to 19.

[0060] [Mathematical Formula 1]

[0061] P=A*B / C

[0062] In the above mathematical expression 1, A is the volume average particle size (㎛) of the powder, B is the crushing strength (N), and C is the specific surface area (m 2 / g) is the value.

[0063]

[0064] According to one embodiment, the volume average particle diameter of the primary particles may be from about 15 to about 150 μm.

[0065] That is, rather than using hydroxyapatite as a catalyst in its crystalline form or in its powder form, a molded body formed into powder is used as a catalyst. At this time, the particle size of the powder constituting the molded body, i.e., the primary particles, may be about 15 to about 150 ㎛, or about 15 ㎛ or more, or about 17 ㎛ or more, or about 20 ㎛ or more, or about 23 ㎛ or more, or about 25 ㎛ or more, and may be about 150 ㎛ or less, or about 140 ㎛ or less, or about 130 ㎛ or less, or about 120 ㎛ or less, or about 110 ㎛ or less, or about 100 ㎛ or less.

[0066] When the primary particles, i.e., hydroxyapatite powder, used to manufacture a shaped catalyst are too small, the powder density within the catalyst shaped catalyst increases, which tends to increase the physical strength. However, this characteristic may cause a problem in that the specific surface area required for the dehydration reaction is reduced. When the primary particles, i.e., hydroxyapatite powder, are too large, the strength of the catalyst shaped catalyst is weak, making it impossible to shape, and problems such as side reactions due to catalyst crushing in the dehydration reaction and increased differential pressure in the reactor may occur.

[0067]

[0068] In one example, the hydroxypropionic acid and its derivatives dehydration reaction catalyst may have an alkali metal content of about 3 wt% to about 8 wt%.

[0069] In hydroxyapatite compounds used as catalysts for the production of unsaturated carboxylic acids or their derivatives, the content of alkali metal in the compound can affect the selectivity in the production of unsaturated carboxylic acids and their derivatives. Specifically, a low content of alkali metal in the catalyst, particularly on the catalyst surface, reduces selectivity, whereas a high content of alkali metal can maintain high selectivity.

[0070] Meanwhile, the molar ratio of calcium to phosphorus on the catalyst surface (Ca / P molar ratio) affects the product yield, i.e., the acrylic acid conversion rate. If the Ca / P molar ratio is too high or too low, the yield may decrease.

[0071] However, when producing unsaturated carboxylic acids or their derivatives, it is difficult to improve both selectivity and conversion simultaneously because selectivity and conversion exhibit a trade-off relationship.

[0072] According to one example of the present invention, the alkali metal content in the catalyst can be maintained at a high level of about 3 wt% to about 8 wt%, and the alkali metal content on the catalyst surface can also be maintained at a high level. Accordingly, the alkali metal content on the catalyst surface can be increased while simultaneously controlling the mixing ratio with Ca and P, thereby further improving the selectivity and conversion rate in the production of unsaturated carboxylic acids and their derivatives.

[0073] Specifically, in the catalyst according to an example, the molar ratio of calcium to phosphorus (P) on the catalyst surface (Ca / P molar ratio) may be about 1.0 or more and about 1.2 or less. More specifically, it may be about 1.0 or more, or about 1.05 or more, or about 1.1 or more, and about 1.2 or less, or less than about 1.2, or about 1.15 or less.

[0074] And, the total molar ratio of calcium and alkali metal to phosphorus on the catalyst surface (molar ratio of (Ca+M) / P) may be about 1.2 or more and about 1.6 or less. More specifically, it may be about 1.2 or more, or about 1.3 or more, and about 1.6 or less, or less than about 1.6, or about 1.5 or less, or about 1.45 or less, or about 1.4 or less.

[0075] The above catalyst may have a high content of alkali metal present on the catalyst surface of about 4 wt% or more and about 8 wt% or less, based on the total weight of elements present on the catalyst surface. More specifically, it may be about 4 wt% or more, or about 5 wt% or more, or about 6 wt% or more, or about 6.5 wt% or more, and about 8 wt% or less, or about 7.5 wt% or less, or about 7 wt% or less.

[0076] Meanwhile, in the present invention, the atomic weight-based element content (at%) of elements including phosphorus, calcium, and alkali metals on the catalyst surface can be measured through XPS analysis.

[0077] From the content (at%) of calcium (Ca), the elemental content (at%) of phosphorus (P), and the elemental content (at%) of alkali metal (M) calculated through the XPS analysis above, the molar ratio of calcium to phosphorus on the catalyst surface can be obtained from the ratio of Ca elemental content (Ca at%) / P elemental content (P at%). In addition, the total molar ratio of calcium to phosphorus and alkali metal can be obtained from the ratio (Ca at%+ M at%) / (P at%).

[0078] In addition, the content (weight%, wt%) of alkali metal present on the catalyst surface can be calculated from the element content (at%) calculated above.

[0079] By controlling the content ratio of phosphorus, calcium and alkali metals on the catalyst surface and the content of the above elements in the catalyst, as described above, the selectivity and conversion rate can be further improved in the production of unsaturated carboxylic acid or its derivative.

[0080]

[0081] Specifically, the content of the alkali metal in the catalyst may be about 3 wt% or more and about 5 wt% or less based on the total weight of the catalyst. More specifically, the content of the alkali metal in the catalyst may be about 3 wt% or more, or about 3.2 wt% or more, and about 5 wt% or less, or about 4.5 wt% or less, about 4 wt% or less, or about 3.7 wt% or less based on the total weight of the catalyst.

[0082] And, the molar ratio of calcium to phosphorus (Ca / P molar ratio) in the catalyst may be about 1.3 or more and about 1.5 or less. More specifically, it may be about 1.3 or more, or about 1.35 or more, or about 1.4 or more, and about 1.5 or less, or about 1.45 or less.

[0083] The total molar ratio of calcium and alkali metal (M) to phosphorus in the catalyst (molar ratio of (Ca+M) / P) may be about 1.2 or more and about 2 or less. More specifically, it may be about 1.2 or more, or about 1.5 or more, or about 1.6 or more, or about 1.65 or more, or about 1.7 or more, and about 2 or less, or about 1.9 or less, or about 1.8 or less, or about 1.75 or less.

[0084] Meanwhile, in the present invention, the content of elements including phosphorus, calcium, and alkali metals in the catalyst can be calculated through inductively coupled plasma spectrometry (ICP), more specifically, inductively coupled plasma optical emission spectrometry (ICP-OES).

[0085]

[0086] According to the invention, the alkali metal may be sodium or potassium, and sodium may be preferred in consideration of its superior improving effect.

[0087] As described above, the catalyst according to the present invention can simultaneously achieve high selectivity and high conversion in the production of unsaturated carboxylic acid or its derivatives by controlling the content ratio of phosphorus, calcium and alkali metals within an optimal range on the catalyst surface and the entire surface.

[0088]

[0089] As an example, the apparent density value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst is about 0.8 to about 1.0 g / cm 3 This can be problematic. If the density is too low, the catalyst strength may be weak, which may lead to side reactions due to catalyst destruction during the dehydration reaction, and problems such as increased pressure differential within the reactor may occur. If the density is too high, the specific surface area may decrease.

[0090]

[0091] According to one example, the crushing strength value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst may be about 6 to about 20 N. That is, the catalyst according to one example of the present invention has an extremely excellent crushing strength value, so that even when exposed to harsh reaction conditions in a state filled inside a reactor, it is not easily crushed, and the filling state can be maintained in the same form as the initial state.

[0092]

[0093] According to one example, the specific surface area value of the hydroxypropionic acid and its derivatives dehydration reaction catalyst is about 50 to about 90 m 2 / g, or about 50 m 2 / g or more, or about 55 m 2 / g or more, or about 60 m 2 / g or more, about 90 m 2 / g or less, or about 85 m2 / g or less, it can have a large specific surface area.

[0094]

[0095] And, the hydroxypropionic acid and its derivative dehydration reaction catalyst may have a P value represented by the following mathematical formula 1 of about 3.5 to about 19, or about 3.5 or more, or about 4.0 or more, or about 5.0 or more, or about 6.0 or more, and may be about 19 or less, or about 17 or less, or about 15 or less, or about 12 or less, or about 10 or less.

[0096] [Mathematical Formula 1]

[0097] P=A*B / C

[0098] In the above mathematical expression 1, A is the volume average particle size (㎛) of the powder, B is the crushing strength (N), and C is the specific surface area (m 2 / g) is the value.

[0099] The above mathematical expression 1 is a parameterization of factors that can directly affect the strength of a catalyst formed by primary particle powder. If the parameter value is too large or too small, the catalyst deactivation time may be shortened, resulting in a problem of a decrease in catalyst performance and a decrease in long-term stability.

[0100]

[0101] In addition, according to another aspect of the invention, a method for producing a hydroxypropionic acid and derivative dehydration reaction catalyst is provided, comprising the steps of: preparing a slurry by adding 1 to 50 parts by weight of a binder to 100 parts by weight of hydroxyapatite; forming the slurry to produce a molded article; and drying the molded article.

[0102]

[0103] According to one example, the manufacturing method may further include a step of grinding hydroxyapatite prior to adding the binder.

[0104]

[0105] For grinding, it may be preferable to use a milling machine such as a jet mill or pin mill in order to control the particle size of the grinding powder produced, i.e., the volume average particle diameter of the primary particles.

[0106]

[0107] The above binder may include a solvent of water or alcohol series (excluding isopropyl alcohol) and isopropyl alcohol, which is a binder component.

[0108] According to an example, the binder may be used in an amount of about 1 part by weight or more, about 5 parts by weight or more, or about 10 parts by weight or more, and about 70 parts by weight or less, or about 60 parts by weight or less, or about 50 parts by weight or less, based on 100 parts by weight of hydroxyapatite.

[0109] If the amount of the above binder used is too little or too much, the formability may be reduced during catalyst production, and the strength of the manufactured catalyst may be reduced.

[0110] However, the content of the binder may vary depending on the particle size, drying temperature, drying time, and other molding conditions.

[0111] And, the binder may include about 0.1 parts by weight or more, or about 1 part by weight or more, or about 3 parts by weight or more, and about 10 parts by weight or less, or about 9 parts by weight or less, or about 8 parts by weight or less of isopropyl alcohol.

[0112] If the content of isopropyl alcohol is too low or too high, the strength of the catalyst being manufactured may be reduced or the specific surface area may be reduced.

[0113] In the step of preparing a slurry by adding a binder to the hydroxyapatite powder and mixing, the mixing method, etc. is not particularly limited.

[0114]

[0115] And, when manufacturing a molded body by molding a slurry, a molding method using an extruder or the like may be preferable.

[0116]

[0117] Afterwards, the molded body formed into a pellet or the like is dried. In the drying step, drying can be performed for about 30 minutes to about 24 hours under conditions of about 10°C or higher, or about 20°C or higher, and about 120°C or lower, or about 110°C or lower.

[0118]

[0119] According to one example, the step of calcining the dried catalyst may be further included.

[0120]

[0121] Meanwhile, the present disclosure provides a method for producing acrylic acid, comprising a step of subjecting a hydroxycarboxylic acid or a derivative thereof to a dehydration reaction in the presence of the aforementioned catalyst.

[0122]

[0123] Meanwhile, the present specification provides a method for producing an unsaturated carboxylic acid and its derivatives using the above catalyst.

[0124] Specifically, the above manufacturing method includes a step of subjecting a hydroxycarboxylic acid or a derivative thereof to a dehydration reaction in the presence of a catalyst for producing the unsaturated carboxylic acid or a derivative thereof.

[0125]

[0126] Specific examples of hydroxycarboxylic acids that serve as raw materials in the method for producing unsaturated carboxylic acids and derivatives thereof according to the present invention include lactic acid, citric acid, 3-hydroxypropionic acid, 3-hydroxy-2-methylpropionic acid, 3-hydroxybutanoic acid, 3-hydroxy-2-methylbutanoic acid, or 2,3-dimethyl-3-hydroxybutanoic acid, and their salts, esters, or dimers and other derivatives thereof can be used.

[0127] The above hydroxycarboxylic acid or its derivative may be used in the form of an aqueous solution dissolved in water, or may be used in the form of a solution dissolved in a mixed solvent in which a hydrophilic organic solvent such as alcohol or ether is mixed with water.

[0128] At this time, the concentration of hydroxycarboxylic acid or its derivative is not particularly limited, but may be 20 wt% or more and 60 wt% or less in consideration of efficiency.

[0129] In addition, the amount of catalyst to be used in the above dehydration reaction can be appropriately selected by considering the type of reactant, reaction time, etc. For example, hydroxycarboxylic acid or its derivative can be added in an amount of 0.05 g or more and 3 g or less per hour per 1 g of catalyst, and more specifically, it can be added in an amount of 0.1 g or more and 1 g or less per hour, or in an amount of 0.5 g or more per hour.

[0130] Additionally, the dehydration reaction can be performed as a continuous reaction using a fixed bed reactor or as a batch reaction. More specifically, it can be performed as a continuous reaction in which the catalyst is charged into a fixed bed reactor and reactants are continuously supplied to the reactor for reaction, thereby continuously producing products.

[0131] In a continuous reaction using the above fixed bed reactor, an inert gas such as nitrogen, argon, or helium may be used as a carrier gas. The amount of carrier gas input is not particularly limited and may be appropriately determined according to reaction conditions such as the amount of reactant input. For example, the carrier gas may be input at a rate of 5 ml / min or more and 500 ml / min or less per 1 g of catalyst.

[0132] In addition, the dehydration reaction may be performed at a temperature of 300°C or higher and 500°C or lower. More specifically, it may be performed at a temperature of 300°C or higher, or 350°C or higher, or 360°C or higher, and 500°C or lower, or 450°C or lower, or 380°C or lower.

[0133] In addition, the above dehydration reaction can be performed at a pressure of 0.5 bar or more and 5 bar or less. More specifically, it can be 0.5 bar or more, or 0.8 bar or more, 5 bar or less, or 2 bar or less, and even more specifically, it can be performed under atmospheric pressure (1±0.2 bar) conditions.

[0134] Also, the reactant hydroxycarboxylic acid or its derivative is 0.05 h -1 Above, 3 h -1 It can be injected at the following Weight Hour Space Velocity (WHSV). More specifically, 0.05 h -1 or 0.1 h -1 or 0.3 h -1 That's it, 3 h -1 or less, or 1 h -1 or less than 0.8 h -1 It can be deployed at WHSV speeds below.

[0135] When the reaction temperature exceeds 500°C, the reaction pressure is less than 0.5 bar, or the reactant supply rate WHSV is 0.1 h -1 If it is less than 300℃, the catalytic activity may increase excessively, causing a hydrogenation cracking side reaction to occur, which may result in a decrease in selectivity. On the other hand, if the reaction temperature is less than 300℃, the reaction pressure is more than 5 bar, or the reactant supply rate WHSV is less than 1 h -1 If it exceeds , the conversion rate decreases, other reaction conditions must be harshly increased, and as a result, there is a concern that the catalyst life will be shortened and the cost in the product separation and recovery step will increase.

[0136] By the dehydration reaction described above, at least a portion of the hydroxycarboxylic acid or its derivative is converted into an unsaturated carboxylic acid or its derivative.

[0137] The method for producing an unsaturated carboxylic acid or a derivative thereof according to the present invention can produce an unsaturated carboxylic acid and a derivative thereof in a high yield by improving the conversion rate for the unsaturated carboxylic acid by using the above-described catalyst.

[0138]

[0139] A catalyst according to one example of the present invention has high reaction yield and selectivity, and excellent life characteristics.

[0140]

[0141] Hereinafter, the functions and effects of the invention will be described in more detail through specific examples. However, these examples are provided merely as examples of the invention and do not define the scope of the invention.

[0142]

[0143] <Example>

[0144] Catalyst manufacturing

[0145] Example 1

[0146] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0147] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0148] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 26 ㎛.

[0149] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 60°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0150]

[0151] Example 2

[0152] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0153] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0154] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 42 ㎛.

[0155] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 60°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0156]

[0157] Example 3

[0158] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0159] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0160] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 60 ㎛.

[0161] For 100 parts by weight of the obtained particles, 25 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 30°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0162]

[0163] Example 4

[0164] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0165] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0166] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 80 ㎛.

[0167] To 100 parts by weight of the obtained particles, 35 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 100°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0168]

[0169] Example 5

[0170] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0171] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0172] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 90 ㎛.

[0173] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 70°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0174]

[0175] Comparative Example 1

[0176] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0177] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0178] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 12 ㎛.

[0179] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 120°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0180]

[0181] Comparative Example 2

[0182] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0183] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0184] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 8 ㎛.

[0185] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 5 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 60°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0186]

[0187] Comparative Example 3

[0188] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0189] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0190] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 160 ㎛.

[0191] For 100 parts by weight of the obtained particles, 28 parts by weight of water and 10 parts by weight of isopropyl alcohol as a binder were added, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder. The pellets were dried at about 60°C for about 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0192]

[0193] Comparative Example 4

[0194] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0195] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0196] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 220 ㎛.

[0197] For 100 parts by weight of the obtained particles, 35 parts by weight of water was added as a binder, mixed well, and pellets of approximately 2.5 mm in size were manufactured using an extruder. The pellets were dried at approximately 150°C for approximately 12 hours to obtain a catalyst molded body in the form of a solid pellet.

[0198]

[0199] Comparative Example 5

[0200] 35 g of HAP and 65 g of CaPP were mixed and placed in a high-temperature, high-pressure reactor, 500 ml of 1 M NaOH solution was added, and the mixture was reacted for 4 hours at 150°C and 5 atm. The resulting white precipitate was filtered and washed to obtain a powdery Na-HAP component catalyst (yield: 90%).

[0201] The powdered catalyst obtained above was finely ground using a jet mill or pin mill. During the grinding, the particle size of the produced particles was controlled by varying the conditions of the milling machine.

[0202] As a result of measuring the particle size using a wet PSD (Particle Size Distribution) analysis device (Microtrac S3500), the average volume particle size was measured to be approximately 500 ㎛.

[0203] For 100 parts by weight of the obtained particles, 25 parts by weight of water and 8 parts by weight of isopropyl alcohol were added as a binder, mixed well, and pellets of about 2.5 mm in size were manufactured using an extruder, but molding failed.

[0204]

[0205] Measurement of crushing strength

[0206] The crushing strength of a single pellet was measured using a strength tester according to ASTM D4179.

[0207]

[0208] Density measurement

[0209] Using COPLEY Tap density, tap density was measured by equalizing the number of taps.

[0210]

[0211] Surface area measurement

[0212] The specific surface area of ​​the catalyst was calculated from the nitrogen gas adsorption amount at liquid nitrogen temperature (77 K) using BELSORP-mino II of BEL Japan.

[0213]

[0214] Lactic acid dehydration reaction progresses

[0215] About 0.71 g of the catalyst prepared in the above Preparation Example 1 was charged into a fixed bed reactor, and a 30 wt% aqueous solution of lactic acid was added at a reaction temperature of 370°C and a normal pressure (1±0.2 bar) at a WHSV of 0.67 h. -1 The dehydration reaction was performed by supplying it.

[0216] During the initial 4 hours of the reaction, the reactants were removed to allow for the reaction stabilization time, and then the liquid product obtained over 2 hours was recovered as a liquid sample using a cooling collector at 4°C, and the reaction was continuously carried out.

[0217] The acrylic acid recovery rate was monitored, and the point at which the recovery rate reached its maximum value was confirmed to indicate that the reaction was activated. The time when the recovery rate decreased by 10% from the reference value was used as the reference point, and the catalyst deactivation time was measured.

[0218] The measurement results are summarized in the table below.

[0219]

[0220] Bulk density (g / ml) Crushing strength (N) Specific surface area (m 2 / g)(*)P=A*B / CDeactivation time (hour)Example 10.9115.864.36.448Example 20.9215.979.18.450Example 30.9610.180.57.555Example 40.919.282.48.958Example 50.919.083.59.759Comparative Example 10.9315.558.43.238Comparative Example 20.9315.745.52.836Comparative Example 30.858.470.419.141Comparative Example 40.815.965.219.943

[0221] (*)A is the particle size, B is the crushing strength, and C is the specific surface area value.

[0222]

[0223] Referring to the table above, in some comparative examples, the deactivation time reached a certain level, but in these cases, the strength was significantly reduced. In cases where the catalyst's crushing strength is low, as in these comparative examples, the catalyst molded body located beneath the catalyst packing layer, which experiences a high load as the reaction progresses, breaks, ultimately preventing the catalyst packing layer from maintaining its shape, thereby compromising the long-term stability of the reaction.

[0224] However, it can be confirmed that the catalyst according to the embodiment of the present invention has a large specific surface area, a very high crushing strength, and excellent long-term stability of the catalyst, which can be estimated by the deactivation time.

Claims

1. Contains a molded body in which primary particles of hydroxyapatite are aggregated, The average volume diameter of the above primary particles is 15 to 150 ㎛; A dehydration reaction catalyst of hydroxypropionic acid and its derivatives, having a P value of 3.5 to 19, represented by the following mathematical formula 1: [Mathematical Formula 1] P=A*B / C In the above mathematical expression 1, A is the volume average particle size (㎛) of the powder, B is the crushing strength (N), and C is the specific surface area (m 2 / g) is the value.

2. In paragraph 1, The average volume diameter of the above primary particles is 25 to 100 ㎛, Hydroxypropionic acid and its derivatives dehydration reaction catalyst.

3. In paragraph 1, An alkali metal content of 3 wt% to 8 wt%, Hydroxypropionic acid and its derivatives dehydration reaction catalyst.

4. In paragraph 3, The above alkali metal is sodium or potassium, a catalyst for the dehydration reaction of hydroxypropionic acid and its derivatives.

5. In paragraph 1, Apparent density value is 0.8 to 1.0 g / cm 3 Dehydration reaction catalyst of phosphorus, hydroxypropionic acid and its derivatives.

6. In paragraph 1, A dehydration reaction catalyst for hydroxypropionic acid and its derivatives having a crushing strength value of 6 to 20 N.

7. In paragraph 1, The specific surface area value is 50 to 90 m 2 / g, hydroxypropionic acid and its derivatives dehydration reaction catalyst.

8. A step of preparing a slurry by adding 1 to 50 parts by weight of a binder to 100 parts by weight of hydroxyapatite; A step of forming the above slurry to produce a molded body; and A method for producing a dehydration reaction catalyst for hydroxypropionic acid and its derivatives, comprising a step of drying the above-mentioned molded body.

9. In paragraph 8, A method for producing a hydroxypropionic acid and its derivative dehydration reaction catalyst, wherein the binder comprises 0.1 to 10 parts by weight of isopropyl alcohol per 100 parts by weight of hydroxyapatite.

10. A method for producing acrylic acid, comprising a step of dehydrating hydroxycarboxylic acid or a derivative thereof in the presence of a catalyst according to paragraph 1.