Patent Application
20230390743
The present invention belongs to the field of dibasic amine preparation, and in particular relates to a catalyst for producing dibasic amine by hydrogenation of dibasic nitrile and a process for preparing the same, a process for producing dibasic amine by hydrogenation of dibasic nitrile and use thereof.
m-Xylylenediamine (meta-benzenedimethanamine) can be used as raw material for epoxy resin curing agent. The curing agent made from m-xylylenediamine can be used as a modified epoxy resin curing agent due to containing aromatic aliphatic amine. Its characteristics include the accelerated curing rate at room temperature; good heat resistance, water resistance, and reagent resistance; and good wetting curing ability and surface gloss. It is widely used in coatings, adhesives, and electronic-grade products.
m-Xylylenediamine is also used as raw material for synthesizing MX nylon and its derivatives, especially MXD6, which is prepared together with adipic acid. This nylon is characterized by high strength and elasticity over a high temperature range, high deformation temperature, low thermal expansion rate (equivalent to alloys). It is suitable for the precision molding and can be used for high-temperature baking and coating. The produced film has high transparency and oxygen impermeability, and is suitable for food packaging. The produced fiber has a high strength.
m-Xylylenediamine can also be used as raw material for polyurethane resin. This can be used to prepare meta-bis(isocyanatomethyl)benzene, which can further synthesize polyurethane resin. This resin is comparable to hexamethylene diisocyanate and has better yellowing resistance than the latter. It can be used in light colored coatings with high coating hardness and low toxicity, and can also be used in synthetic leather.
At present, m-xylylenediamine is mostly produced by catalytic hydrogenation of isophthalonitrile.
Patent application No. CN200680036084.8 discloses a process flow for preparing MXDA (m-xylylenediamine) from IPN (isophthalonitrile) by fixed-bed continuous hydrogenation method. At 170-200° C., IPN is melted and mixed in a liquid form with liquid ammonia and recycled material and dissolved (60° C.). Under the conditions of 60-130° C. and 150-200 bar, in the fixed-bed reactor under the catalysis of Mn-doped non-supported Co catalyst, the per-pass conversion rate is >99%, and the selectivity is >92%.
Patent application No. CN200680035201.9 discusses using the product MXDA recycle material as the IPN solvent, and dissolving at 55-70° C. The technical processes provided in patent applications CN201010150757.0 and CN201010150725.0 mainly comprise: adding the modified Raney Ni catalyst into the stirred reactor in advance, then pumping isophthalonitrile and a ternary mixed solvent (an aromatic hydrocarbon, a low-carbon alcohol, an aliphatic halogenated derivative) and a secondary amine as inhibitor. After dissolved, the reaction is performed at 40-120° C. under 2-10 MPa in a stirred tank to (intermittently) produce MXDA through the hydrogenation.
However, in the prior art, there are still problems such as large catalyst consumption, unsatisfactory product selectivity, and intermittent operation of high-pressure autoclave. Therefore, it is necessary to develop new catalysts with high activity and high selectivity and realize continuous industrial production.
The technical problem to be solved by the present invention is to provide a new catalyst for preparing m-xylylenediamine in high selectivity and a process for preparing the same, in response to the low selectivity in producing m-xylylenediamine by hydrogenation of isophthalonitrile in the prior art.
Therefore, the first aspect of the present invention provides a catalyst for producing dibasic amine by hydrogenation of dibasic nitrile, which comprises the following components or reaction product thereof:
According to some embodiments of the present invention, the relative content of α-NiO in the catalyst is less than 1.5 a.u., preferably less than 0.2 a.u.
According to some embodiments of the present invention, the auxiliary comprises one or more of Cu, Co, Zr, Mo and/or oxides thereof.
The content in “relative content” of the present invention is not an absolute concept of content, but refers to a relative content of a substance determined by comparison of the integral areas of the peaks in the same graph in the same coordinate system, where the size of the integral area of the peak represents the content of the substance in the catalyst. Specifically, for the relative content of α-NiO of the present invention (using a.u. as the unit), the same graph in the same coordinate system refers to the H2-TPR diagram of the catalyst, where the abscissa is the temperature in degrees Celsius (° C.), and the ordinate is the signal value of the TCD (thermal conductivity detector) (it is a quantitative value, for example expressed in the form of a percentage or a decimal). For the relative content of α-NiO of the present invention, when measuring H2-TPR, a catalyst in a fully oxidized state is used, and the amount of the catalyst is 50 mg.
In the present invention, a.u. is an abbreviation of arbitrary unit, which refers to a relative value and is dimensionless.
According to some embodiments of the present invention, the total weight of the catalyst is 100 wt %.
The content of the active component is 5-70 wt %, preferably 10-60 wt %, more preferably 15-50 wt %; the content of the auxiliary is 0.1-60 wt %, preferably 1-50 wt %, more preferably 5-45 wt %; the content of said support is 10-90 wt %, preferably 15-80 wt %, more preferably 20-70 wt %.
According to some other examples of the present invention, based on the parts by weight, the content of the active component is 10-60 parts, preferably 15-55 parts; the content of the auxiliary is 0.1-120 parts, preferably 0.2-90 parts; the content of said support is 0.1-45 parts, preferably 1-35 parts.
According to some embodiments of the present invention, said support is at least one of alumina, silica and zeolite, preferably alumina.
According to some embodiments of the present invention, said support is a support that has been treated at a high temperature of not less than 500° C.
The second aspect of the present invention provides a process for preparing the catalyst according to the first aspect of the present invention, wherein the process comprises the following steps:
According to some embodiments of the present invention, in step 1), the solution of auxiliary salt and the solution of first precipitant are simultaneously added to the water containing the support to perform the first contact.
According to some embodiments of the present invention, in step 2), the solution of auxiliary salt and the solution of second precipitant are simultaneously added to the water containing the modified support obtained from step 1) to perform the second contact.
According to some embodiments of the present invention, in step 1), the resulting solution in the first contact is controlled to the endpoint pH of 6.0-10.0, for example 6.0-8.0.
According to some embodiments of the present invention, in step 2), the resulting solution in the second contact is controlled to the endpoint pH of 6.0-10.0, for example 6.0-8.0.
According to some embodiments of the present invention, the temperature of said first contact is 50-90° C., in some embodiments, said temperature is 70° C.
According to some embodiments of the present invention, the time of said first contact is 3-6 hours.
According to some embodiments of the present invention, the temperature of said second contact is 50-90° C.
According to some embodiments of the present invention, the time of said second contact is 3-6 hours.
According to some embodiments of the present invention, said auxiliary salt is selected from one or more of Mg(NO3)2, Cu(NO3)2, Co(NO3)2, Zn(NO3)2, Zr(NO3)4, and (NH4)2MoO4, preferably selected from one or more of Cu(NO3)2, Zr(NO3)4, (NH4)2MoO4 and Co(NO3)2.
According to some embodiments of the present invention, the auxiliary salt may be a hydrate of salt, for example one or more of Mg(NO3)2·6H2O, Cu(NO3)2·3H2O, Co(NO3)2·6H2O, Zn(NO3)2·6H2O and Zr(NO3)4·5H2O.
According to some embodiments of the present invention, said first precipitant is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate and ammonia water, preferably sodium hydroxide and/or ammonia water.
According to some embodiments of the present invention, said nickel salt is nickel sulphate and/or nickel nitrate, preferably nickel nitrate.
According to some embodiments of the present invention, said second precipitant is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate and ammonia water, preferably selected from one or more of sodium hydroxide, sodium carbonate and sodium bicarbonate.
According to some embodiments of the present invention, in step 1), said solution of auxiliary salt has a concentration of 0.1-1.5 mol/L, preferably 0.3-1.2 mol/L.
According to some embodiments of the present invention, in step (1), said solution of first precipitant has a concentration of 0.4-2.0 mol/L, preferably 0.6-1.6 mol/L.
According to some embodiments of the present invention, in step (1), the content of said support in water is 5-100 g/L, for example 20-80 g/L, or 5-20 g/L, e.g. 8-15 g/L.
According to some embodiments of the present invention, in step 2), said solution of nickel salt has a concentration of 0.2-1.5 mol/L, preferably 0.5-1.2 mol/L.
According to some embodiments of the present invention, in step 2), said solution of second precipitant has a concentration of 0.4-2.0 mol/L, preferably 0.6-1.5 mol/L.
According to some embodiments of the present invention, in step 2), the content of said modified support in water is 10-100 g/L, for example 20-85 g/L, or 10-30 g/L, e.g. 12-25 g/L.
According to some embodiments of the present invention, in step 2), the calcining is performed in an air atmosphere.
According to some embodiments of the present invention, in step 2), the calcining temperature is 300-600° C.
According to some embodiments of the present invention, in step 2), a solution of the nickel salt and a solution of the second precipitant are simultaneously added to the water containing the modified support under the condition of 50-90° C., and mixed, the mixed solution is controlled to the endpoint pH of 6.0-10.0, for example 6.0-8.0, stirred for 3-6 hours, filtered, washed, dried, and calcined at 300-600° C. in an oxygen-containing atmosphere (such as air atmosphere or pure oxygen) to produce a catalyst.
The third aspect of the present invention provides a process for producing dibasic amine by hydrogenation of dibasic nitrile, which comprises contacting the dibasic nitrile with hydrogen gas in the presence of the catalyst according to the first aspect of the present invention or the catalyst prepared with the process according to the second aspect of the present invention to react to produce the dibasic amine.
According to some embodiments of the present invention, the reaction temperature is 50-120° C., preferably 60-80° C.
According to some embodiments of the present invention, said reaction pressure is 4.0-15.0 MPa, for example, 4.0-12.0 MPa, or 6.0-10.0 MPa.
According to some embodiments of the present invention, the liquid hourly space velocity of said reaction is 1-12 hr−1, preferably 2-10 hr−1.
According to some embodiments of the present invention, the molar ratio of hydrogen gas to dibasic nitrile of said reaction is 3:1-70:1, preferably 5:1-20:1.
According to some embodiments of the present invention, said isophthalonitrile is dissolved in liquid ammonia. In some embodiments, the mass fraction of isophthalonitrile is 10%. In some embodiments, the mass fraction of said liquid ammonia is 90%.
The fourth aspect of the present invention provides use of the catalyst according to the first aspect of the present invention, or the catalyst prepared with the process according to the second aspect of the present invention, or the process according to the third aspect of the present invention in producing dibasic amine by hydrogenation of dibasic nitrile, especially producing m-xylylenediamine by hydrogenation of isophthalonitrile.
Generally speaking, the present invention provides the following technical solutions:
The fully oxidized state described herein refers to a catalyst obtained by calcining the corresponding catalyst in an oxygen-containing atmosphere (such as air atmosphere or pure oxygen) at a certain calcining temperature (e.g. 300-600° C.) for a long enough time (e.g. 4 hours, 8 hours, 12 hours, 24 hours, 48 hours, 96 hours, 1 week, 2 weeks, 4 weeks or longer), and the fully oxidized state can also be achieved by other methods, not limited to the above-mentioned calcining methods.
For example, the reaction temperature is 50-120° C., for example 60-80° C.; and/or said reaction pressure is 4.0-15.0 MPa, for example 4.0-12.0 MPa, further for example 6.0-10.0 MPa; and/or the liquid hourly space velocity of said reaction is 1-12 hr−1, for example 2-10 hr−1.
In the present invention, there is no special limitation on dibasic amines and dibasic nitriles, wherein the dibasic nitrile can be aliphatic C4-C24 dibasic nitriles, such as adiponitrile, pimelonitrile, suberonitrile, nonanedinitrile, decanedinitrile, undecanedinitrile, dodecanedinitrile, tridecanedinitrile, tetradecanedinitrile, pentadecanedinitrile, hexadecanedinitrile, heptadecanedinitrile, or octadecanedinitrile, or aromatic C6-C18 dibasic nitriles, such as phthalonitrile, isophthalonitrile, or terephthalonitrile;
The dibasic amine can be aliphatic C4-C24 dibasic amine such as hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, or octadecanediamine, or aromatic C6-C18 dibasic amine such as ortho-benzenedimethanamine, meta-benzenedimethanamine, or para-benzenedimethanamine.
For the supported nickel-based catalyst, there are usually three forms of NiO: free amorphous α-NiO, β1-NiO weakly interacting with the support, and β2-NiO strongly interacting with the support. Too much free amorphous α-NiO in the catalyst will lead to more excessive hydrogenation side reactions to generate hydrogenolysis by-products such as 3-methylbenzylamine and m-xylene.
Herein, the content of α-NiO refers to the weight percent or the relative content of α-NiO relative to the total amount of nickel species as NiO in the catalyst when the catalyst is converted into the fully oxidized state.
The present invention aims at the influence of different NiO types of nickel-based catalysts on the selectivity of target products, and provides a catalyst and process for producing diamine by hydrogenation of dibasic nitrile, especially for producing m-xylylenediamine by hydrogenation of isophthalonitrile. The catalyst and the process of the present invention greatly reduce the generation of excessive hydrogenation by-products and improve the overall selectivity of target products.
wherein (1) α-NiO (300-400° C.): attributed to free amorphous NiO species on the surface; (2) β1-NiO (400-500° C.): attributed to the NiO species weakly interacting with the support; (3) β2-NiO (500-600° C.): attributed to the NiO species strongly interacting with the support.
In order to make the present invention easier to understand, the present invention will be described in detail below in conjunction with the embodiments and accompanying drawings. These embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The used reagents or instruments, for which the manufacturers are not indicated herein, are commercially available or obtained by conventional methods.
The end points of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include the values close to these ranges or values. For numerical ranges, the endpoints of the ranges to each other, the endpoints of the ranges and the individual point values, and the individual point values to each other can be combined with each other to give one or more new numerical ranges, and these new numerical ranges should be construed as specifically disclosed herein.
In the concept used in the present invention, the conversion ratio and the selectivity for producing m-xylylenediamine by hydrogenation of isophthalonitrile are calculated by the following equations:
in which, n: the amount of substance, in unit of mol; IPN: isophthalonitrile; MXDA: m-xylylenediamine; 1: raw materials; 2: product.
1. The test method for the relative content of different types of NiO: the area integration of the H2-TPR curve (the ordinate is % TCD, and the abscissa is temperature) is performed, and the relative content of different types of NiO is calculated based on the hydrogen consumption of the sample, and the unit is a.u. (arbitrary unit). The size of the peak area actually represents the relative content of different types of NiO, and is used for the mutual comparison of NiO between different samples.
In the following examples, the isophthalonitrile used is of the industrial grade and dissolved in liquid ammonia, the mass fraction of isophthalonitrile is 10%, and the mass fraction of liquid ammonia is 90%; the volume fraction of the used hydrogen gas is 99.9%.
The constitution of the catalyst is measured according to the X-ray fluorescence method (with reference to “Petrochemical Analysis Method (RIPP Test Method)”, edited by Yang Cuiding et al., Science Press, published in 1990).
Preparation of modified support: the auxiliary salt Co(NO3)2 was made into a solution I with a concentration of 0.8 mol/L, sodium hydroxide was made into a solution II with a concentration of 1.0 mol/L, and the precursor of the aluminum hydroxide support (pseudo-boehmite) was pretreated at a high temperature of 500° C. and placed in 1 L of water. At 70° C., solution I and solution II were co-currently precipitated, and the endpoint pH was controlled to 7.0. The aging while stirring was performed for 3-6 hours to produce a modified alumina support.
Preparation of catalyst: nickel nitrate was made into a solution III with a concentration of 0.8 mol/L, sodium carbonate was made into a solution IV with a concentration of 1.2 mol/L, and the obtained modified alumina support (50 g) was placed in 1 L of water. At 70° C., solution III and solution IV were co-currently precipitated, and the endpoint pH was controlled to 7.5. The aging while stirring was performed for 4 hours, and then filtering, washing, drying, and calcining in the air atmosphere at 500° C. for 6 hours were performed to produce a catalyst. In the resulting catalyst, the weight of CoO was 0.75 g, the weight of the active component as nickel oxide was 5.25 g, and the weight of the alumina support was 9.0 g. The H2-TPR diagram was shown in
15 g of the obtained catalyst was taken, which contained CoO (0.75 g) in the catalyst components. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
(3) Producing m-Xylylenediamine by Hydrogenation of Isophthalonitrile
A solution of isophthalonitrile in liquid ammonia (3000 mL, the mass fraction of isophthalonitrile was 10%, the mass fraction of liquid ammonia was 90%) and a pure hydrogen gas (the volume fraction of hydrogen gas was 99.9%) were used as raw materials, the used amount of the reduced catalyst was 15 g, and the hydrogenation test was performed under the following conditions: the reaction temperature was 80° C., the reaction pressure was 8.0 MPa, the hydrogen gas/isophthalonitrile molar ratio was 5:1, and the liquid hourly space velocity was 10 hr−1. The reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 97.1%. The content of 3-methylbenzylamine was 0.32% (measured by liquid chromatography).
The catalyst of this example was prepared by the preparation method of the catalyst in Example 1, except that a different content of Co was used in the catalyst: the weight of CoO in the catalyst was 2.25 g. The H2-TPR diagram was shown in
15 g of the catalyst was taken, which contained CoO (2.25 g) in the catalyst. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 98.3%. The content of 3-methylbenzylamine was 0.13%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 1, except that a different content of Co was used in the catalyst: the weight of CoO in the catalyst was 0.5 g. The result of the relative content of α-NiO was shown in Table 1.
15 g of the catalyst was taken, which contained CoO (0.5 g) in the catalyst. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 96.4%. The content of 3-methylbenzylamine was 0.42%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 1, except that a different content of Co was used in the catalyst: the weight of CoO in the catalyst was 4.5 g. The result of the relative content of α-NiO was shown in Table 1.
15 g of the catalyst was taken, which contained CoO (4.5 g) in the catalyst. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 98.4%. The content of 3-methylbenzylamine was 0.11%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 1, except that a different content of Co was used in the catalyst: the weight of CoO in the catalyst was 7.5 g. The result of the relative content of α-NiO was shown in Table 1.
15 g of the catalyst was taken, which contained CoO (7.5 g) in the catalyst. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 98.5%. The content of 3-methylbenzylamine was 0.09%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 2, except that a different auxiliary salt was used: it was Zr(NO3)4. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 98.0%. The content of 3-methylbenzylamine was 0.17%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 2, except that a different auxiliary salt was used: it was Mg(NO3)2. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 97.8%. The content of 3-methylbenzylamine was 0.23%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 2, except that a different auxiliary salt was used: it was Cu(NO3)2. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.7%, the MXDA selectivity was 96.9%. The content of 3-methylbenzylamine was 0.36%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 2, except that a different auxiliary salt was used: it was Zn(NO3)2. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.8%, the MXDA selectivity was 96.4%. The content of 3-methylbenzylamine was 0.41%.
The catalyst of this example was prepared by the preparation method of the catalyst in Example 2, except that a different auxiliary salt was used: it was (NH4)2MoO4. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
The method was the same as that in Example 1, and the reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 98.1%. The content of 3-methylbenzylamine was 0.19%.
The solution of the auxiliary salt Co(NO3)2, the solution III of nickel nitrate, and the solution of the precipitant in Example 1 were added together to the water containing the aluminum hydroxide support having been treated at a high temperature of 500° C., and the endpoint pH of the solution was controlled to 7.0 so that the nickel salt, the auxiliary salt and the precipitant were precipitated together on the support alumina. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the obtained catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
(3) Producing m-Xylylenediamine by Hydrogenation of Isophthalonitrile
A solution of isophthalonitrile in liquid ammonia (3000 mL, the mass fraction of isophthalonitrile was 10%, the mass fraction of liquid ammonia was 90%) and a pure hydrogen gas (the volume fraction of hydrogen gas was 99.9%) were used as raw materials, the used amount of the catalyst was 15 g, and the hydrogenation test was performed under the following conditions: the reaction temperature was 80° C., the reaction pressure was 8.0 MPa, the hydrogen gas/isophthalonitrile molar ratio was 5:1, and the liquid hourly space velocity was 10 hr−1. The reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 95.2%. The content of 3-methylbenzylamine was 0.49%.
The process was identical to that of Example 1 except that the solution of auxiliary salt Co(NO3)2 was not added during the preparation of the catalyst. The H2-TPR diagram was shown in
15 g of the obtained catalyst was taken, which contained no CoO in the catalyst components. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours.
(3) Producing m-Xylylenediamine by Hydrogenation of Isophthalonitrile
A solution of isophthalonitrile in liquid ammonia (3000 mL, the mass fraction of isophthalonitrile was 10%, the mass fraction of liquid ammonia was 90%) and a pure hydrogen gas (the volume fraction of hydrogen gas was 99.9%) were used as raw materials, the used amount of the reduced catalyst was 15 g, and the hydrogenation test was performed under the following conditions: the reaction temperature was 80° C., the reaction pressure was 8.0 MPa, the hydrogen gas/isophthalonitrile molar ratio was 5:1, and the liquid hourly space velocity was 10 hr−1. The reaction results were shown in Table 1. The IPN conversion rate was 99.9%, the MXDA selectivity was 95.6%. The content of 3-methylbenzylamine was 0.58%.
The process was identical to that of Example 1 except that the alumina support had not been treated at a high temperature of 500° C. The result of the relative content of α-NiO in the catalyst was shown in Table 1.
15 g of the obtained catalyst was taken. The catalyst was loaded to 15 mL, and reduced with pure hydrogen gas at 500° C. for 24 hours to produce a reduced catalyst.
(3) Producing m-Xylylenediamine by Hydrogenation of Isophthalonitrile
A solution of isophthalonitrile in liquid ammonia (3000 mL, the mass fraction of isophthalonitrile was 10%, the mass fraction of liquid ammonia was 90%) and a pure hydrogen gas (the volume fraction of hydrogen gas was 99.9%) were used as raw materials, the used amount of the catalyst was 15 g, and the hydrogenation test was performed under the following conditions: the reaction temperature was 80° C., the reaction pressure was 8.0 MPa, the hydrogen gas/isophthalonitrile molar ratio was 5:1, and the liquid hourly space velocity was 10 hr−1. The reaction results were shown in Table 1. The IPN conversion rate was 99.8%, the MXDA selectivity was 94.9%. The content of 3-methylbenzylamine was 0.45%.
It should be noted that the above-mentioned embodiments are only used to explain the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but it is to be understood that the words used therein are words of description and explanation, rather than words of limitation. The present invention may be modified within the scope of the claims of the present invention as specified, and may be modified without departing from the scope and spirit of the present invention. Although the present invention described herein refers to the specific methods, materials and embodiments, it is not intended to be limited to the specific examples disclosed therein, but rather, the present invention extends to all other methods and applications having the same function.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202011164914.3 | Oct 2020 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/126727 | 10/27/2021 | WO |
