CN116041142A - Process for preparing 2-propyl-1-heptanol - Google Patents

Abstract

The invention relates to the technical field of alkanol hydrogenation from alkenal, and discloses a method for preparing 2-propyl-1-heptanol. The method comprises: in the presence of a catalyst, making 2-propyl-2-heptenal A hydrogenation reaction occurs in contact with hydrogen; wherein, the preparation method of the catalyst includes: contacting alumina microspheres with a nitrogen-containing polymer solution, and then performing a first roasting of the contact product under an inert atmosphere to obtain a carrier, and then activating the metal The components are loaded on the carrier. Adopting the method of the present invention can improve the selectivity of 2-propyl-1-heptanol under the premise of ensuring the conversion rate of 2-propyl-2-heptenal.

Description

Process for preparing 2-propyl-1-heptanol

technical field

The invention relates to the technical field of alkanol hydrogenation from alkenal, in particular to a method for preparing 2-propyl-1-heptanol.

Background technique

In recent years, out of consideration for the safety and environmental protection of plasticized products, the industry has begun to use alcohols with higher carbon numbers to produce plasticizers, and decyl alcohol is one of them. 2-Propyl-1-heptanol is one of the important representatives of decanol. Existing routes for producing 2-propyl-1-heptanol mainly include: (1) Obtain C9 olefins through trimerization of propylene or oligomerization of propylene and butene, and then generate 2- Propyl-1-heptanol; (2) Butene is hydroformylated to form valeraldehyde, then condensed to generate 2-propyl-2-heptenal, and then hydrogenated to obtain 2-propyl-1-heptanol.

CN101185893A discloses a catalyst for gas-phase hydrogenation of decenal to produce isodecyl alcohol and a preparation method thereof. The catalyst is prepared by co-precipitation method, which is composed of copper oxide, zinc oxide, aluminum oxide and coagent; the coagent is one or more of the metal element compounds of Na, K, Ni, Co, Mg, Ca and Ba The molar content of copper oxide, zinc oxide and aluminum oxide is 20-70%, 28-70%, and 1-10% respectively, and the molar content of active auxiliary agent is 0.1-2.0%. The catalyst is used for gas-phase hydrogenation of decenal to produce isodecyl alcohol, and has high conversion rate of decenal and selectivity of isodecyl alcohol. However, the gas-phase hydrogenation reaction needs to be carried out at 140-180°C, and subsequent condensation and separation are required, resulting in high energy consumption and complicated processes.

CN1883795A discloses a method for preparing a copper-zinc-aluminum gas-phase aldehyde hydrogenation catalyst. The active components are 10-60% CuO, 20-80% ZnO, 0.1-20% Al ₂ O ₃ , and graphite is used as a carrier for compression molding. Prepare the catalyst. Adopting the step-by-step continuous co-precipitation method, changing the step-by-step intermittent feeding method to a continuous feeding method, the prepared catalyst has a large specific surface and pore volume, a high dispersion of active metal copper, and a greatly improved catalyst activity. However, the gas phase reaction method needs to gasify the raw material aldehyde. For decenal, it is easy to polymerize in the process of gasification phase transition, which reduces the selectivity of the target product alcohol.

CN102666455A A method for preparing decanol by hydrogenating decenal. The method requires at least two reactors, wherein the first reactor uses a copper-based and/or nickel-based catalyst, and the second reactor uses a palladium or ruthenium catalyst, all of which are carried out on a solid catalyst in a liquid phase. The method can hydrogenate decenal into decanol in high yield, and the content of unsaturated decenal in the hydrogenation output is less than 1500ppm. The hydrogenation method of the invention is relatively complicated, and a plurality of reactors are connected in series, and the second reactor uses an expensive noble metal catalyst.

CN104513131B discloses a method for preparing decanol by liquid-phase hydrogenation of decenal. The method uses a Raney nickel catalyst supported by an organic polymer, and decenal flows through the catalyst bed in a liquid state under a hydrogen atmosphere, so that decanol can be obtained with high yield and high selectivity. However, the catalyst is Raney nickel, the price is relatively high and there is a certain risk of combustion during use.

CN106179373A proposes a catalyst for liquid-phase hydrogenation of decenal to produce isodecyl alcohol and a preparation method thereof. The three active components of nickel, copper and chromium are supported on the alumina carrier by precipitation method, and the prepared catalyst has higher conversion rate of isodecanal and selectivity of isodecanol. However, the presence of chromium can cause great harm to the environment and health.

CN113019378A discloses a kind of enal hydrogenation catalyst, and this catalyst can be used for decenal hydrogenation and prepares decyl alcohol, comprises: NiO 5-50%, CuO 5-25%, MgO 0.1-10%, surplus is gamma-Al2O3 . The catalyst is mixed with γ-alumina powder, magnesium source and water-soluble organic matter, and after solid-liquid separation, the product is obtained by first drying and first roasting successively as an intermediate carrier; the obtained intermediate carrier, alumina precursor and Additives are mixed, followed by molding, second drying and second calcination to obtain the carrier; the carrier is impregnated with a mixed solution containing nickel and copper, and after solid-liquid separation, the third drying and third calcination are carried out successively to obtain the alkenal hydrogenation catalyst. It has good anti-coking performance and catalytic activity, which can prolong the service life of the catalyst. However, the catalyst belongs to the traditional molding method, and the particle size distribution of the obtained catalyst is wide, and the particle spacing is large when the catalyst is loaded, and hot spots are prone to appear during the reaction process.

Contents of the invention

In order to solve the problems existing in the prior art that noble metals are used as catalysts for the hydrogenation of alkanols to alkanols, the catalyst cost is high, the metal chromium is used to cause environmental pollution, and the process route of the multi-step hydrogenation method is complex and unsuitable for industrial applications. The invention provides a method for preparing 2-propyl-1-heptanol.

It is well known in the art that for the decanol with an annual output of 100,000 tons, under the condition that the conversion rate remains unchanged, the annual economic benefit can be increased by about 2 million for every 1% increase in the selectivity; The energy consumption of distillation and separation is reduced to achieve the purpose of energy saving, emission reduction and efficiency increase. Therefore in order to improve the decanol selectivity, the invention provides a kind of method for preparing 2-propyl-1-heptanol, described method comprises: in the presence of catalyst, make 2-propyl-2-heptenal and The hydrogenation reaction occurs when hydrogen is contacted;

Wherein, the preparation method of the catalyst includes: contacting the alumina microspheres with a nitrogen-containing polymer solution, and then performing the first roasting on the contact product under an inert atmosphere to obtain a carrier, and then loading the metal active component on the carrier.

The present invention uses specific alumina microspheres to do carbon and nitrogen doping to obtain a carrier, and then supports metal active components to obtain the catalyst of the present invention. The catalyst of the present invention adopts a one-step hydrogenation method to carry out the hydrogenation of 2-propyl-2-heptenal to prepare 2-propyl-1-heptanol and obtain a higher 2- Propyl-2-heptenal conversion and 2-propyl-1-heptanol selectivity.

Detailed ways

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

In the present invention, unless otherwise specified, the diameter of the alumina microspheres refers to the average diameter of the alumina microspheres.

The invention provides a method for preparing 2-propyl-1-heptanol, the method comprising: in the presence of a catalyst, 2-propyl-2-heptenal is contacted with hydrogen to undergo a hydrogenation reaction;

Wherein, the preparation method of the catalyst includes: contacting the alumina microspheres with a nitrogen-containing polymer solution, and then performing the first roasting on the contact product under an inert atmosphere to obtain a carrier, and then loading the metal active component on the carrier.

According to the present invention, preferably, the particle diameter of the alumina microspheres is 200-800 μm, and the coefficient of variation is 3-8%.

According to the present invention, the source of the alumina microspheres is not particularly limited, as long as the particle diameter and coefficient of variation of the alumina microspheres meet the defined range. The alumina microspheres can be prepared by referring to the method described in CN110203953B or CN110282642B. Preferably, the preparation method of the alumina microspheres comprises: using aluminum sol as the dispersed phase, taking an organic solvent as the continuous phase, forming the dispersed phase into droplets under the shearing action of the continuous phase, and solidifying to obtain the gel microspheres , and then dried and calcined to obtain alumina microspheres.

In the method for preparing alumina microspheres according to the present invention, preferably, the aluminum sol has a solid content of 5-8 wt%.

In the method for preparing alumina microspheres according to the present invention, preferably, the organic solvent used in the process of preparing alumina microspheres is C1-C10 monohydric saturated alcohol, preferably octanol.

In the method for preparing alumina microspheres according to the present invention, the drying temperature may be 100-120° C., and the drying time may be 3-15 hours.

In the method for preparing alumina microspheres according to the present invention, the calcination temperature may be 550-1200° C., and the calcination time may be 4-10 hours.

According to the present invention, preferably, the alumina microspheres are prepared in a microchannel reactor. The type of the microchannel reactor is not particularly limited, and the microchannel reactor is a single-channel reactor and/or a multi-channel reactor.

According to a further preferred embodiment of the present invention, the multi-channel reactor is an eight-channel reactor. The structure of the eight-channel reactor is described, and the eight-channel reactor includes a continuous phase distribution layer, a first droplet generation layer, a second droplet generation layer and a dispersed phase distribution layer, wherein the continuous phase distribution layer The layer is composed of a petal-shaped resistance distribution channel and eight fluid outlets at the end, a continuous phase vertical inlet and four positioning holes. Each branch of the fluid passing through is called a first level, and a certain resistance is added before each fluid branch. The width decreases with the increase of the radius of the circle where the starting end of each stage is located; the first droplet generation layer is distributed with eight T-shaped channels, four positioning holes and eight through holes to meet the flow of the continuous phase from the distribution layer to the generation layer. Layer requirements, the structure of the second droplet generation layer is similar to that of the first droplet generation layer, and at the same time, eight droplet outlets are distributed at the end of the main channel of the T-shaped channel; the structure of the dispersed phase distribution layer is similar to that of the continuous phase distribution layer, In addition to the petal-shaped resistance distribution channel and the eight dispersed phase outlets at its end, there is also a dispersed phase fluid inlet and eight product outlets.

According to the present invention, preferably, an eight-channel reactor is used as an example to illustrate the process of preparing alumina microspheres of the present invention. With aluminum sol as the dispersed phase and organic solvent as the continuous phase, adjust the continuous phase flow rate so that the continuous phase fills the continuous phase distribution layer and flows into the droplet generation layer, and then flows out from the outlet. The continuous phase flow rate is finally stabilized at 6-10mL/min , adjust the flow rate of the dispersed phase to 1-4mL/min, so that the dispersed phase fills the dispersed phase distribution layer and flows into the droplet generation layer, and further generates droplets under the shearing action of the continuous phase, and the droplets solidify in the oil column to form a gel The microspheres are dried and calcined to obtain alumina microspheres with a diameter of 200-800 μm and a coefficient of variation of 3-8%.

According to the present invention, the amount of the nitrogen-containing polymer can be selected within a wide range, preferably, relative to 100g of alumina microspheres, the amount of the nitrogen-containing polymer solution in terms of the nitrogen-containing polymer is 0.1 -1g.

According to the present invention, the contact conditions of the alumina microspheres and the nitrogen-containing polymer solution can be selected within a wide range, preferably, the contact temperature is 100-120°C, and the contact time is 4-10h.

According to the present invention, the type of the nitrogen-containing polymer can be selected within a wide range, preferably, the nitrogen-containing polymer in the nitrogen-containing polymer solution is a polymer containing a nitrogen heterocycle, preferably polyethylene At least one of polyvinyl imidazole, polyvinyl pyridine and polyvinyl pyrrolidone, more preferably polyvinyl imidazole.

According to the present invention, the concentration of the nitrogen-containing polymer in the nitrogen-containing polymer solution is not particularly limited, preferably, the concentration of the nitrogen-containing polymer in the nitrogen-containing polymer solution is 0.1-1 wt%. (For example, it can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%).

According to the present invention, preferably, the solvent used in the preparation of the nitrogen-containing polymer solution is alcohol, preferably C1-C4 saturated alcohol, more preferably methanol and/or ethanol.

According to the present invention, the conditions of the first calcination can be selected within a wide range, preferably, the temperature of the first calcination is 400-800° C., and the time is 2-10 h.

According to the present invention, preferably, the preparation method of the catalyst further includes first drying the product obtained by contacting the alumina microspheres with the nitrogen-containing polymer solution, and then performing the first calcination, more preferably, the first dried The temperature is 60-80°C, and the time is 4-12h.

According to the present invention, preferably, the metal active component is Ni.

According to the present invention, preferably, relative to 20 g of carrier, the amount of the metal active component calculated as metal element is 5-20 g.

According to the present invention, preferably, the amount of the metal active component is such that in the obtained catalyst, the content of the metal active component in terms of metal elements is 15-50 wt%.

According to the present invention, preferably, the manner of loading the metal active component on the support is to impregnate the support with an impregnation solution containing the metal active component, and then perform a second calcination under an inert atmosphere.

According to the present invention, preferably, the metal-containing active component impregnating solution is prepared by dissolving a water-soluble metal salt in water, and more preferably, the mass percentage of the metal in the metal-containing active component impregnating solution The content is 10-15wt%.

According to the present invention, the conditions of immersion in the immersion liquid can be selected within a wide range, preferably, the temperature of the immersion is 30-40°C, and the time is 1-5h.

In the present invention, the impregnation method can be any one of the impregnation methods commonly used in the art, such as equal-volume impregnation method, excessive impregnation method, can be one-time impregnation, or multiple impregnation, as long as it can make the metal active The loading of the components only needs to meet the requirements.

According to the present invention, the conditions of the second calcination can be selected within a wide range, preferably, the temperature of the second calcination is 300-600° C., and the time is 4-8 hours.

According to the present invention, preferably, the preparation method of the catalyst further includes performing the first calcination after the second drying of the impregnated carrier, more preferably, the temperature of the second drying is 80-120° C., and the time is 4-12h.

According to the present invention, preferably, the conditions of the hydrogenation reaction include: a temperature of 50-200°C, preferably 90-150°C, a hydrogen pressure of 0.5-8MPa, preferably 3-5MPa, 2-propyl-2- The liquid hourly mass space velocity of heptenal is 0.01-5h ^-1 , preferably 0.02-0.1h ^-1 .

According to the present invention, preferably, the 2-propyl-2-heptenal is contacted with hydrogen in the form of a 2-propyl-2-heptenal solution, and the 2-propyl-2-heptenal solution is The solvent in is C1-C10 saturated alcohol.

According to the present invention, preferably, the molar ratio of the 2-propyl-2-heptenal to hydrogen is 1:50-100.

According to the present invention, preferably, the weight ratio of the 2-propyl-2-heptenal to the C1-C10 saturated alcohol is 1:5-10.

According to the present invention, preferably, the C1-C10 saturated alcohol is decyl alcohol.

The present invention will be described in detail below by way of examples. In the following examples,

Decenal conversion rate = (moles of decenal in the raw material - moles of unreacted decenal) ÷ moles of decenal in the raw material × 100%.

Decanol selectivity=the number of moles of decanol in the product÷(the number of moles of decenal in the raw material-the number of moles of unreacted decenal)×100%.

The diameter of alumina microspheres was tested by scanning electron microscopy.

The test method of the coefficient of variation: measure the number of alumina microspheres in a unit area through a scanning electron microscope, and measure the diameter of each alumina microsphere, and then calculate it according to the formula of the coefficient of variation.

The coefficient of variation is calculated according to the following formula:

所有氧化铝微球颗粒直径平均值。CV: coefficient of variation, n: particle count of alumina microspheres, _Xi : diameter of individual alumina microspheres,

The average diameter of all alumina microspheres.

Preparation example

A microstructure reactor is used to prepare alumina microspheres. The dispersed phase is aluminum sol with a solid content of 7.5wt%. The continuous phase and the liquid in the oil column are organic solvent octanol. First, adjust the flow rate of the continuous phase so that the continuous phase is filled with the continuous phase. The distribution layer flows into the droplet generation layer, and then flows out from the outlet. The flow rate of the continuous phase is finally stabilized at 6-10mL/min. Then adjust the flow rate of the dispersed phase to 1-4mL/min, so that the dispersed phase fills the dispersed phase distribution layer and flows into the droplet generation layer, and further generates droplets under the shearing action of the continuous phase. The droplets were solidified in the oil column to obtain gel microspheres, dried at 120°C for 12 hours, and calcined at 600°C for 4 hours to obtain alumina microspheres with a diameter of 345 μm and a coefficient of variation of 7.2%.

Example 1

(1) The alumina microsphere 100g that preparation example obtains is immersed in the ethanol solution of the polyvinylimidazole (wherein the consumption of polyvinylimidazole is 1g) that concentration is 1wt%, then transfers to in the hydrothermal kettle at 100 ℃ React for 10 hours, cool and filter, dry at 80° C. for 4 hours, then place in nitrogen atmosphere, and bake at 400° C. for 10 hours to obtain a carrier (carbon-doped alumina microspheres).

(2) 20 grams of carrier is placed in 15wt% nickel nitrate aqueous solution (wherein the consumption of nickel nitrate in terms of metal elements is 5g), after soaking at 30°C for 5h, the carrier is taken out, drained, and dried at 80°C for 12 hours, Calcined at 600° C. for 4 hours in a nitrogen atmosphere to obtain a catalyst.

Characterized by X-ray fluorescence spectroscopic analysis (XRF), the loading amount of nickel in the catalyst is 18.9wt%.

Example 2

Step (1) is identical with embodiment 1.

(2) 20 grams of carrier is placed in 15wt% nickel nitrate aqueous solution (wherein the consumption of nickel nitrate in terms of metal elements is 5g), after soaking at 30°C for 5h, the carrier is taken out, drained, and dried at 80°C for 12 hours, Baking at 600° C. for 4 hours in a nitrogen atmosphere.

(3) Repeat the operation of step (2) 3 times to obtain the catalyst.

Characterized by XRF, the nickel loading in the catalyst is 43.7wt%.

Example 3

(1) The aluminum oxide microsphere 100g that preparation example obtains is immersed in the ethanol solution of the polyvinylimidazole (wherein the consumption of polyvinylimidazole is 0.1g) that concentration is 0.1wt%, then transfers to in the hydrothermal kettle React at 120°C for 4 hours, cool and filter, dry at 60°C for 12 hours, then place in a nitrogen atmosphere, and bake at 800°C for 2 hours to obtain a carrier (carbon-doped alumina microspheres).

(2) 20 grams of carrier is placed in 15wt% nickel nitrate aqueous solution (wherein the consumption of nickel nitrate in terms of metal elements is 5g), after soaking at 40°C for 1h, the carrier is taken out, drained, and dried at 120°C for 4 hours, Baking at 300° C. for 8 hours in a nitrogen atmosphere.

(3) Repeat the operation of step (2) 3 times to obtain the catalyst.

Characterized by XRF, the nickel loading in the catalyst is 44.7wt%.

Comparative example 1

The catalyst was prepared according to the method of Example 1, except that the carrier was replaced by alumina tooth balls (purchased from Yinuokai Biotechnology Co., Ltd., with a particle size of 3-4mm).

Characterized by XRF, the nickel loading in the catalyst is 19.5wt%.

Comparative example 2

The catalyst was prepared according to the method of Example 2, except that the carrier was replaced by alumina tooth balls (purchased from Yinuokai Biotechnology Co., Ltd., with a particle size of 3-4mm).

Characterized by XRF, the nickel loading in the catalyst is 45.3wt%.

Comparative example 3

The preparation of the catalyst was carried out according to the method of Example 1, except that the process of preparing the carrier in step (1) was not included, that is, alumina microspheres were directly used as the carrier.

Characterized by XRF, the nickel loading in the catalyst is 19.7wt%.

test case

The performance of preparing 2-propyl-1-heptanol by the catalysts of the above-mentioned examples and comparative examples to 2-propyl-2-heptenal liquid-phase hydrogenation was tested, and 20 mL of catalysts were loaded into the reactor, and In the atmosphere, after reduction at 450°C for 4 hours, hydrogen, liquid 2-propyl-2-heptenal and solvent (2-propyl-1-heptanol) were continuously fed, the reaction temperature, the pressure of hydrogen, the 2-propane The liquid hourly weight space velocity of base-2-heptenal and the weight ratio of 2-propyl-2-heptenal and solvent are shown in Table 1, and the test results are shown in Table 1.

Table 1

Note: Decenal in Table 1 refers to 2-propyl-2-heptenal.

As can be seen from the results in Table 1, the catalyst prepared by the method of the present invention has a higher -Propyl-2-heptenal conversion and higher selectivity to 2-propyl-1-heptanol. Comparing Comparative Example 1-2 with Example 1-3, the metal active component content in the catalyst is basically equivalent, and under the same hydrogenation test conditions, the catalyst of Example 1-3 can be used to ensure that 2-propyl On the premise of the conversion rate of 2-heptenal, the selectivity of 2-propyl-1-heptanol is further improved, and the selectivity is increased by more than 1%.

The preferred embodiments of the present invention have been described in detail above, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (10)

1. A method for preparing 2-propyl-1-heptanol, characterized in that, the method comprises: in the presence of a catalyst, 2-propyl-2-heptenal is contacted with hydrogen to undergo a hydrogenation reaction ; Wherein, the preparation method of the catalyst includes: contacting the alumina microspheres with a nitrogen-containing polymer solution, and then performing the first roasting on the contact product under an inert atmosphere to obtain a carrier, and then loading the metal active component on the carrier. 2 . The method according to claim 1 , wherein, relative to 100 g of alumina microspheres, the nitrogen-containing polymer solution is used in an amount of 0.1-1 g. 3 . The method according to claim 1 , wherein the temperature at which the alumina microspheres are in contact with the nitrogen-containing polymer solution is 100-120° C. and the time is 4-10 hours. 4. The method according to claim 1, wherein the alumina microspheres have a diameter of 200-800 μm and a coefficient of variation of 3-8%; And/or, the nitrogen-containing polymer in the nitrogen-containing polymer solution is a polymer containing a nitrogen heterocycle, preferably at least one of polyvinylimidazole, polyvinylpyridine and polyvinylpyrrolidone, more preferably is polyvinylimidazole; And/or, the concentration of the nitrogen-containing polymer in the nitrogen-containing polymer solution is 0.1-1wt%; And/or, the solvent used in preparing the nitrogen-containing polymer solution is alcohol, preferably C1-C4 saturated alcohol, more preferably methanol and/or ethanol. 5. The method according to claim 1, wherein the temperature of the first calcination is 400-800° C., and the time is 2-10 h. 6. The method according to claim 1, wherein, relative to the 20g carrier, the amount of the metal active component in terms of metal elements is 5-20g; And/or, the metal active component is Ni. 7. The method according to claim 1, wherein the method of loading the metal active component on the carrier is to impregnate the carrier with an impregnation solution containing the metal active component, and then carry out the second calcination under an inert atmosphere ; Preferably, the impregnation temperature is 30-40°C, and the time is 1-5h; Preferably, the temperature of the second calcination is 300-600° C., and the time is 4-8 hours. 8. The method according to claim 1, wherein the conditions of the hydrogenation reaction include: a temperature of 50-200°C, preferably 90-150°C, a hydrogen pressure of 0.5-8MPa, preferably 3-5MPa, 2 The liquid hourly mass space velocity of -propyl-2-heptenal is 0.01-5h ^-1 , preferably 0.02-0.1h ^-1 . 9. The method according to claim 8, wherein the 2-propyl-2-heptenal is contacted with hydrogen in the form of a solution of 2-propyl-2-heptenal, and the 2-propyl-2-heptenal is The solvent in the 2-heptenal solution is a C1-C10 saturated alcohol; And/or, the molar ratio of the 2-propyl-2-heptenal to hydrogen is 1:50-100. 10. The method according to claim 9, wherein the weight ratio of the 2-propyl-2-heptenal to the C1-C10 saturated alcohol is 1:5-10; And/or, the C1-C10 saturated alcohol is decyl alcohol.