CN116037098A - Catalyst for preparing alpha-olefin by alcohol dehydration, preparation method thereof and method for preparing alpha-olefin by alcohol dehydration - Google Patents

Catalyst for preparing alpha-olefin by alcohol dehydration, preparation method thereof and method for preparing alpha-olefin by alcohol dehydration Download PDF

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CN116037098A
CN116037098A CN202111262338.0A CN202111262338A CN116037098A CN 116037098 A CN116037098 A CN 116037098A CN 202111262338 A CN202111262338 A CN 202111262338A CN 116037098 A CN116037098 A CN 116037098A
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oxide
catalyst
group
transition metal
main component
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田保亮
向良玉
张筱榕
彭晖
宋超
唐国旗
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/613—10-100 m2/g
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    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
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    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
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    • C07C2523/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups C07C2523/02 - C07C2523/36 with rare earths or actinides
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Abstract

The invention relates to the technical field of alcohol dehydration, in particular to a catalyst for preparing alpha-olefin by alcohol dehydration, a preparation method thereof and a method for preparing alpha-olefin by alcohol dehydration, wherein the catalyst comprises the following components: 84-99.88wt% of main component, 0.04-6wt% of IIA oxide, 0.05-8wt% of IIIB oxide and 0.03-10wt% of transition metal oxide; wherein the main component is selected from at least one of IVB-group oxides; the transition metal oxide is selected from at least one of group VIB oxide, group VIII oxide, group IB oxide and group IIB oxide. According to the invention, the IIA metal element, the IIIB metal element and the VIB, VIII, IB, IIB metal element are introduced into the main component to reasonably modify the catalyst, so that the carbon deposition phenomenon of the catalyst in the alcohol dehydration reaction can be inhibited, the catalytic performance of the catalyst is improved, and the efficient performance of the alcohol dehydration reaction for preparing alpha-olefin is promoted.

Description

Catalyst for preparing alpha-olefin by alcohol dehydration, preparation method thereof and method for preparing alpha-olefin by alcohol dehydration
Technical Field
The invention relates to the technical field of alpha-olefin preparation by alcohol dehydration, in particular to a catalyst for preparing alpha-olefin by alcohol dehydration, a preparation method thereof and a method for preparing alpha-olefin by alcohol dehydration.
Background
Alpha-olefins being of the formula CH 2 The terminal olefin of =ch-R (R is an alkyl group) is a petrochemical raw material which has been rapidly developed in recent years, and is widely used in various fields such as oil additives, surfactants, plasticizers, bactericides, emulsifiers, and the like. The preparation method of the alpha-olefin comprises alcohol dehydration, paraffin cracking, solvent extraction, fischer-Tropsch synthesis, ethylene oligomerization and the like; the method has the advantages of simple alcohol dehydration process route, mild reaction conditions, high product purity, easy separation, cleaner production process and low energy consumption in the rectification process, and meets the current requirement on green chemical synthesis, and the method is developed into industrial-scale production later. The development of a novel catalyst is a key for solving the technical problem of preparing alpha-olefin by catalyzing alcohol dehydration.
CN 101940938A discloses a heteropolyacid modified alumina ethanol dehydration catalyst and a preparation method thereof; the catalyst comprises the following components in parts by weight: a) 0.5-30 parts of heteropolyacid, b) 70-99.5 parts of oxidationAluminum, wherein the heteropolyacid is selected from H X AB 12 O 40 ·nH 2 O or (NH) 4 ) m HpAB 12 O 40 ·nH 2 O has at least one of the heteropoly acids of keggin structure. The invention mainly solves the problems of higher cost and low ethylene yield of the ethanol dehydration catalyst in the prior art. However, the heteropolyacid catalyst and the product of the invention are difficult to separate, so that the catalyst is difficult to recover.
CN 112275315a discloses a sulfur-modified metal-supported molecular sieve catalyst, a preparation method thereof and application thereof in preparing isosorbide. The sulfur-modified metal-loaded molecular sieve catalyst is obtained by sequentially modifying an H-type molecular sieve through metal salt and a sulfur-containing compound; the amount of the strong acid is 0.45-0.55mmol g -1 The weak acid content is 0.18-0.31mmol g -1 The ratio of B acid to L acid is 3-4. The catalyst realizes the generation of metal acid active center sites in the molecular sieve, and simultaneously adjusts the surface acidity and the diffusion performance of the molecular sieve, so that the catalyst has proper proportion of B acid and L acid and good anti-coking function, and promotes the efficient implementation of sorbitol dehydration reaction. However, the catalyst modified by sulfate ions has poor thermal stability, short service life, easy carbon deposition and inactivation, and SO 4 2- The easy loss in liquid phase reaction leads to the reduction of catalytic activity, thereby limiting the application thereof in industrial production.
EP 3233765B1 discloses a heteropolyacid catalyst with mixed oxide as carrier and its use in the production of ethylene by dehydration of ethanol; the supported heteropolyacid catalyst comprises the following components: i) The mixed oxide of silicon dioxide and transition metal oxide is used as a carrier, wherein the silicon dioxide accounts for more than 50wt% of the weight of the mixed oxide carrier; or ii) a mixed oxide of zirconia and a different transition metal oxide as a support, wherein zirconia comprises more than 50wt% of the weight of the mixed oxide support. Wherein the transition metal oxide is selected from the group consisting of oxides of group IIIB-VIB metals, preferably Sc, Y, la, ti, zr, hf, nb, ta or W. The catalyst exhibits a longer catalyst life in alcohol dehydration reactions than conventional supported heteropolyacid catalysts. However, the specific surface area of the heteropolyacid catalyst is small, which limits the catalytic activity.
CN 108745422A discloses a 1, 4-butanediol dehydration catalyst with adjustable and controllable surface acidity and alkalinity, a preparation method and application thereof; in the method, the carrier is selected from zirconia carriers, and active components are loaded on the zirconia carriers to obtain the supported catalyst. The catalyst prepared by the invention is used for the reaction of preparing 3-butene-1-ol by dehydrating 1, 4-butanediol; however, the catalyst has complex preparation process, complex catalyst composition, relatively low conversion rate of 1, 4-butanediol and selectivity of 3-butene-1-ol.
In view of the above, it is difficult to combine the catalytic activity, the selectivity of the product, the service life and the stability of the existing catalyst for the reaction for preparing α -olefins by dehydration of alcohols.
Disclosure of Invention
The invention aims to solve the problem that the existing catalyst for preparing alpha-olefin by alcohol dehydration is difficult to simultaneously consider the catalytic activity, the selectivity of a product, the service life and the stability, and provides a catalyst for preparing alpha-olefin by alcohol dehydration, a preparation method thereof and a method for preparing alpha-olefin by alcohol dehydration.
In order to achieve the above object, the first aspect of the present invention provides a catalyst for producing α -olefins by dehydration of alcohols, comprising, based on the total amount of the catalyst: 84-99.88wt% of main component, 0.04-6wt% of IIA oxide, 0.05-8wt% of IIIB oxide and 0.03-10wt% of transition metal oxide; wherein the main component is selected from at least one of IVB-group oxides; the transition metal oxide is selected from at least one of group VIB oxide, group VIII oxide, group IB oxide and group IIB oxide.
In a second aspect, the present invention provides a process for preparing a catalyst for the dehydration of alcohols to alpha-olefins, wherein the process comprises: the main component source, IIA group salt, IIIB group salt and transition metal salt are mixed according to the mole ratio of 1:0.0001-0.1:0.0001-0.1: mixing 0.0001-0.1 in solvent to obtain mixed solution; then, the mixed solution is contacted with a precipitator for coprecipitation reaction, and the obtained reaction product is aged; then roasting the aged product;
wherein the main component is selected from at least one of IVB-group metal sources; the transition metal salt is selected from one of a group VIB salt, a group VIII salt, a group IB salt and a group IIB salt.
In a third aspect, the present invention provides a catalyst for preparing alpha-olefins by dehydration of alcohols, prepared by the method according to the second aspect.
In a fourth aspect, the present invention provides a process for the preparation of alpha-olefins by dehydration of alcohols, the process comprising: the dehydration reaction is carried out by contacting an alcohol with the catalyst for producing an alpha-olefin by dehydration of an alcohol described in the first aspect or the third aspect described above in the presence or absence of a carrier gas.
Through the technical scheme, the catalyst is reasonably modified by introducing the IIA group metal element, the IIIB group metal element and the VIB, VIII, IB, IIB group metal element into the main component, so that the carbon deposition phenomenon of the catalyst in the alcohol dehydration reaction can be inhibited, the service life of the catalyst is prolonged, and the efficient operation of the reaction for preparing the alpha-olefin by alcohol dehydration can be realized.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
As previously mentioned, the present invention provides in a first aspect a catalyst for the dehydration of alcohols to α -olefins, wherein the catalyst comprises, based on the total amount of the catalyst: 84-99.88wt% of main component, 0.04-6wt% of IIA oxide, 0.05-8wt% of IIIB oxide and 0.03-10wt% of transition metal oxide; wherein the main component is selected from at least one of IVB-group oxides; the transition metal oxide is selected from at least one of group VIB oxide, group VIII oxide, group IB oxide and group IIB oxide.
According to the invention, the catalyst is reasonably modified by introducing the IIA group metal element, the IIIB group metal element and the transition metal element into the main component, so that the acidity and the alkalinity of the catalyst can be controlled within a certain range, the carbon deposition phenomenon of the catalyst in the alcohol dehydration reaction can be inhibited, the service life of the catalyst is obviously prolonged, and the efficient performance of the alcohol dehydration reaction for preparing alpha-olefin is promoted.
According to the present invention, in order to further reduce the occurrence of side reactions, it is preferable that the catalyst comprises, based on the total amount of the catalyst: 89 to 99.68wt% of a main component, 0.1 to 4wt% of a group IIA oxide, 0.12 to 3.5wt% of a group IIIB oxide, and 0.1 to 3.5wt% of a transition metal oxide.
In some preferred embodiments of the present invention, the group vi B oxide is contained in an amount of 85 parts by weight or more, preferably 89 to 99.68 parts by weight, based on 100 parts by weight of the catalyst, for example, 89 parts by weight, 89.5 parts by weight, 90 parts by weight, 90.5 parts by weight, 91 parts by weight, 91.5 parts by weight, 92 parts by weight, 92.5 parts by weight, 93 parts by weight, 93.5 parts by weight, 94 parts by weight, 94.5 parts by weight, 95 parts by weight, 95.5 parts by weight, 96 parts by weight, 96.5 parts by weight, 97 parts by weight, 97.5 parts by weight, 98 parts by weight, 98.5 parts by weight, 99 parts by weight, 99.68 parts by weight, or any value in the range of any two of the above values.
In some preferred embodiments of the present invention, the group IIA oxide is contained in an amount of 0.04 to 6 parts by weight, preferably 0.1 to 4 parts by weight, for example, may be 0.1 part by weight, 0.5 part by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, or any value in the range of any two of the above values, per 100 parts by weight of the catalyst.
In some preferred embodiments of the present invention, the group IIIB oxide may be present in an amount of 0.05 to 8 parts by weight, preferably 0.12 to 3.5 parts by weight, for example, 0.12 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, or any value in the range of any two values set forth above, per 100 parts by weight of the catalyst, based on the total amount of the catalyst.
In some preferred embodiments of the present invention, the content of the transition metal oxide may be 0.03 to 10 parts by weight, preferably 0.1 to 3.5 parts by weight, for example, may be 0.1 part by weight, 0.15 part by weight, 0.2 part by weight, 0.4 part by weight, 0.8 part by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, or any value in the range of any two of the above-mentioned numerical values, per 100 parts by weight of the catalyst, based on the total amount of the catalyst.
According to the present invention, it is further preferred that the weight ratio of the group IIA oxide, the group iiib oxide, and the transition metal oxide is 0.2 to 20:0.4-10:1, a step of; preferably 0.3-6:0.5-5:1, a step of; more preferably 1 to 5:0.5-2.5:1, a step of; under the preferable conditions, the carbon deposition phenomenon of the catalyst in the alcohol dehydration reaction can be better inhibited, and the service life of the catalyst is further prolonged.
In the invention, in order to improve the coordination performance of the main component, the IIA oxide, the IIIB oxide and the transition metal oxide, the pore channel diffusivity and the pore structure stability of the catalyst are optimized; preferably, the main component is zirconium dioxide.
In the present invention, the group IIA oxide is preferably at least one selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide; more preferably magnesium oxide and/or calcium oxide.
In the present invention, the group IIIB metal is preferably at least one selected from lanthanum oxide, cerium oxide, ytterbium oxide, neodymium oxide and praseodymium oxide; more preferably lanthanum oxide and/or cerium oxide.
In the present invention, the transition metal oxide is preferably at least one selected from the group consisting of chromium oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, and silver oxide; more preferably nickel oxide and/or copper oxide.
In some preferred embodiments of the inventionWherein in the catalyst, the pore volume with the pore diameter in the range of 1.7-2.6nm accounts for more than 65 percent of the total pore volume of the catalyst, and is preferably 70-90 percent; pore volume with the pore diameter smaller than 1.7nm accounts for 0-8% of the total pore volume of the catalyst; in the above preferred embodiments, the selectivity of alpha olefin can be improved, and the carbon deposition phenomenon of the catalyst can be reduced; further preferably, the catalyst has a pore volume of 0.08-0.2 mL.g -1 The specific surface area of the catalyst is 40-120m 2 ·g -1 。
According to the invention, in order to further increase the selectivity of alpha-olefins, the carbon deposition of the catalyst is reduced, the CO of the catalyst 2 The adsorption quantity is 0.15-0.33 mmol.g -1 Preferably 0.27 to 0.33mmol g -1 。
According to the present invention, the amount of the medium strong acid center of the catalyst is preferably less than 45%, preferably less than 25%, based on the total amount of the weak acid center and the medium strong acid center of the catalyst, and the selectivity of the alpha olefin can be further improved and the carbon deposition of the catalyst can be reduced under the above preferred conditions.
The amount of the strong acid center in the catalyst means that the catalyst adopts NH 3 TPD test method, NH at 250-450 DEG C 3 Desorption amount.
In the present invention, the specific surface area, pore volume and the ratio of pore volume of different pore diameters of the catalyst are measured by a nitrogen adsorption-desorption method, see in particular GB/T6609.35-2009.
The present invention is not particularly limited in the manner of compounding the main component and the group IIA oxide, group iiib oxide and transition metal oxide, and the group IIA oxide, group iiib oxide and transition metal oxide may be supported on the main component or may be dispersed in the main component; preferably dispersed in the main component in the present invention. In the present invention, the dispersion or loading of the group IIA oxide, group iiib oxide and transition metal oxide has little influence on the microstructure of the catalyst, and therefore, the resulting catalyst has a similar pore structure to the main component structure.
In the invention, the catalyst can be prepared by adopting the existing method.
In a second aspect, the present invention provides a process for preparing a catalyst for the dehydration of alcohols to alpha-olefins, wherein the process comprises: the main component source, IIA group salt, IIIB group salt and transition metal salt are mixed according to the mole ratio of 1:0.0001-0.1:0.0001-0.1: mixing 0.0001-0.1 in solvent to obtain mixed solution; then, the mixed solution is contacted with a precipitator for coprecipitation reaction, and the obtained reaction product is aged; then roasting the aged product; wherein the main component is selected from at least one of IVB-group metal sources; the transition metal salt is selected from one of a group VIB salt, a group VIII salt, a group IB salt and a group IIB salt.
In the above catalyst preparation method, those skilled in the art will understand that: if the main component source is provided already containing the desired amounts of group IIA salt, group iiib salt and transition metal salt, molding is performed using only such a raw material (main component source), and if the main component source is provided without the group IIA salt, group iiib salt and transition metal salt or element in a low (insufficient) content, the desired element may be additionally introduced.
In the present invention, since the group IIA salt, the group iiib salt and the transition metal salt are introduced during the preparation of the main component, the group IIA salt, the group iiib salt and the transition metal salt are mainly present in the bulk phase of the main component, i.e., dispersed in the main component.
According to the present invention, preferably, the main component source is selected from at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate.
Further preferably, the precipitant is selected from at least one of ammonia, urea, sodium hydroxide and sodium carbonate.
In the present invention, the group IIA salt exists in the form of a solution of a group IIA salt (referred to as solution A), the group IIA salt being selected from at least one of group IIA nitrate, group IIA formate, group IIA oxalate and group IIA lactate; preferably group IIA nitrate; further preferably, the group IIA nitrate is selected from at least one of magnesium nitrate, calcium nitrate, strontium nitrate and barium nitrate, preferably magnesium nitrate and/or calcium nitrate; the solvent in the solution is selected from water and/or ethanol, preferably water.
In the present invention, the group IIIB salt exists in the form of a solution of a group IIIB salt (referred to as solution B), and the group IIIB salt is selected from at least one of a group IIIB nitrate, a group IIIB formate, a group IIIB oxalate and a group IIIB lactate; preferably a group IIIB nitrate; further preferably, the group iiib nitrate is selected from at least one of lanthanum nitrate, cerium nitrate, neodymium nitrate and praseodymium nitrate, preferably lanthanum nitrate and/or cerium nitrate; the solvent in the solution is selected from water and/or ethanol, preferably water.
In the present invention, the transition metal salt is present in the form of a solution of a transition metal salt (referred to as solution C) selected from at least one of a transition metal nitrate, a transition metal formate, a transition metal oxalate and a transition metal lactate; preferably a transition metal nitrate; further preferably, the transition metal nitrate is selected from at least one of chromium nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, zinc nitrate and silver nitrate, preferably nickel nitrate and/or copper nitrate; the solvent in the solution is selected from water and/or ethanol, preferably water.
The invention can mix the solution A, the solution B and the solution C and then add the mixture into a system containing a main component source, or add the mixture into the system containing the main component source separately; when separately added to the system containing the main component source, the order of addition of the solution A, the solution B and the solution C is not particularly limited.
According to the invention, preferably, the aging conditions include: the temperature is 50-90deg.C, for example, 50 deg.C, 55 deg.C, 60 deg.C, 65 deg.C, 70 deg.C, 75 deg.C, 80 deg.C, 85 deg.C, 90 deg.C, or any value in the range of any two values; preferably, the aging time is 1-9h, and may be, for example, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, or any value in the range of any two values described above.
According to the present invention, preferably, the method further comprises: centrifuging, washing and drying the aged product; the drying time can be reasonably selected according to the drying temperature, the amount of materials and the type of drying equipment, and the condition that the water content of the dried materials does not influence the subsequent roasting is taken into account. Preferably, the drying temperature is 80 to 150 ℃, for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, or any value in the range of any two values; the drying time is 5-20h; for example, the value may be 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h, 15.5h, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h, or any value in the range of any two values described above.
According to the present invention, the calcination is capable of removing crystal water in the salt and decomposing the salt to form an oxide, and preferably, the conditions of the calcination include: the temperature is 500-1100 ℃ and the time is 2-20h; illustratively, the firing temperature may be 500 ℃, 525 ℃, 550 ℃, 600 ℃, 625 ℃, 650 ℃, 675 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, or any value in the range of any two values stated above; the firing time may be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h, 15.5h, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h, or any value in the range of any two values recited above.
In a third aspect, the present invention provides a catalyst for preparing alpha-olefins by dehydration of alcohols, prepared by the method according to the second aspect.
Preferably, the catalyst comprises, based on the total amount of the catalyst: 84-99.88wt% of main component, 0.04-6wt% of IIA oxide, 0.05-8wt% of IIIB oxide and 0.03-10wt% of transition metal oxide; wherein the main component is selected from at least one of IVB-group oxides; the transition metal oxide is selected from at least one of VIB group oxide, VIII group oxide, IB group oxide and IIB group oxide;
preferably, the weight ratio of the group IIA oxide, the group iiib oxide and the transition metal oxide is 0.2 to 20:0.4-10:1, a step of; preferably 0.3-6:0.5-5:1, a step of; more preferably 1 to 5:0.5-2.5:1.
preferably, in the catalyst, the pore volume with the pore diameter in the range of 1.7-2.6nm accounts for more than 65% of the total pore volume of the catalyst, and preferably 70-90%; pore volume with the pore diameter smaller than 1.7nm accounts for 0-8% of the total pore volume of the catalyst; the pore volume of the catalyst is 0.08-0.2 mL.g -1 。
Preferably, the specific surface area of the catalyst is 40-120m 2 ·g -1 。
Preferably, the CO of the catalyst 2 The adsorption quantity is 0.15-0.33 mmol.g -1 Preferably 0.27 to 0.33mmol g -1 。
Preferably, the amount of mid-strongly acidic centres of the catalyst is less than 45%, preferably less than 25%, based on the total of the amount of weakly acidic centres and the amount of mid-strongly acidic centres of the catalyst.
In a fourth aspect, the present invention provides a process for the preparation of alpha-olefins by dehydration of alcohols, wherein the process comprises: the dehydration reaction is carried out by contacting an alcohol with the catalyst for producing an alpha-olefin by dehydration of an alcohol described in the first aspect or the third aspect described above in the presence or absence of a carrier gas.
Preferably, the conditions of the dehydration reaction include: the temperature is 240-370 ℃, preferably 250-350 ℃; the pressure is 0.085-0.25MPa; the volume space velocity of the liquid phase is 0.1 to 0.8h -1 Preferably 0.15-0.6h -1 ；
Preferably, when the carrier gas is present, the flow rate of the carrier gas is 15-45mL min -1 Preferably 18-38mL min -1 。
According to the invention, preferably the alcohol is selected from C 2 -C 18 An alcohol of (a); further preferably, the alcohol is selected from the group consisting of 1-propanol, 1-butanol, 1-pentaneAt least one of alcohol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-undecanol, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-hexadecanol, 2-heptadecanol, 2-octadecanol.
In the following examples, the elemental composition of the catalyst was analyzed by plasma emission spectrometry (ICP-MS); test instrument: VISTA Pro CCD spectrometer (Varian);
the specific surface area, pore volume and the ratio of pore volume of different pore diameters of the catalyst are measured by a nitrogen adsorption-desorption method (BET), see GB/T6609.35-2009; instrument name: a fully automatic physico-chemical adsorption analyzer (Automatic Micropore & Chemisorption Analyzer); instrument model: ASAP2420, MICromeritcs, U.S. A.;
CO of catalyst 2 The desorption amount adopts CO 2 -TPD test, desorption temperature 100-600 ℃, test conditions: accurately weighing about 0.1g of sample, placing into a sample tube, and purging with He gas at 10deg.C for min -1 Heating to 600deg.C, standing for 1 hr, cooling to 120deg.C, and changing gas into 10% CO 2 The mixture of He and the catalyst is adsorbed for 60min, then the mixture is changed into He and purged for 1h, counting is started after the baseline is stabilized, and the temperature is 10 ℃ for min -1 And (5) heating to 600 ℃, keeping for 30min, stopping recording, and completing the experiment. Integrating and calculating the peak area to obtain CO 2 Desorption amount (basic site of catalyst); test instrument: a full-automatic chemical adsorption instrument (Automated Catalyst Characterization System); instrument model: autochem 2920, MICROMERITICS, inc. of America;
The amount of the strong acid center in the catalyst adopts NH 3 -TPD test, desorption temperature 250-450 ℃, test conditions: accurately weighing about 0.1g of sample, placing into a sample tube, and purging with He gas at 10deg.C for min -1 Heating to 600 deg.C, standing for 1 hr, cooling to 120 deg.C, and changing gas into 10% NH 3 He mixture, adsorbed for 60min, and then reformedChanging into He gas, purging for 1h, starting counting after the base line is stable, and using 10 ℃ for min -1 And (5) heating to 600 ℃, keeping for 30min, stopping recording, and completing the experiment. Integrating and calculating the peak area to obtain NH 3 Desorption amount. Test instrument: full-automatic chemical adsorption instrument (Automated Catalyst Characterization System) instrument model: autochem 2920, MICROMERITICS, inc. of America.
The amount of weakly acidic center of the catalyst is NH 3 TPD test, desorption temperature is 100-250 ℃, and specific test method is the same as the acid site test method.
The carbon deposition amount of the catalyst adopts O 2 -TPO test, test conditions are: accurately weighing 0.2g of sample, taking argon with the flow rate of 40mL/min as carrier gas, pretreating the sample at 150 ℃ for 60min, cooling to 100 ℃, performing temperature programming oxidation process by programming at the speed of 10 ℃/min to 900 ℃ under the condition that the mixed gas of oxygen with the flow rate of 40mL/min and argon (the oxygen volume fraction is 20%) is taken as analysis gas, and detecting CO in the temperature programming process 2 Signals of gases such as CO. Test instrument: a full-automatic programmed temperature chemical adsorption instrument; instrument model: autochem II 2920, micromeritics Inc. of America.
Example 1
1.62mol of zirconyl nitrate, 0.053mol of calcium nitrate tetrahydrate, 0.034mol of lanthanum nitrate and 0.002mol of chromium nitrate nonahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Ca 2+ The concentration is 0.018mol L -1 、La 3+ The concentration is 0.011mol L -1 、Cr 3+ At a concentration of 0.0007mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 75 ℃ water bath and vigorous stirring, and adjusting the pH to 10.2 to obtain a precipitate system; standing the sediment system in a beaker for 2.4 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 80 ℃ for 2 hours and at 120 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 500 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/La 2 O 3 /Cr 2 O 3 Denoted as catalyst C-1,the test results are shown in tables 1 and 2.
Example 2
1.61mol of zirconyl nitrate, 0.141mol of calcium nitrate tetrahydrate, 0.0014mol of praseodymium nitrate tetrahydrate and 0.086mol of ferric nitrate nonahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Ca 2+ The concentration is 0.047mol L -1 、Pr 3+ At a concentration of 0.0005mol L -1 、Fe 3+ At a concentration of 0.029mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 80 ℃ water bath and vigorous stirring, and adjusting the pH to 9.9 to obtain a precipitate system; standing the precipitate system in a beaker for 2.5h; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 85 ℃ for 2 hours and 130 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 650 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/Pr 2 O 3 /Fe 2 O 3 Catalyst C-2 was recorded and the test results are shown in tables 1 and 2.
Example 3
1.60mol of zirconyl nitrate, 0.0035mol of calcium nitrate tetrahydrate, 0.041mol of neodymium nitrate solution and 0.017mol of cobalt nitrate hexahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.53mol L -1 、Ca 2+ At a concentration of 0.0012mol L -1 、Nd 3+ The concentration is 0.014mol L -1 、Co 3+ The concentration is 0.006mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of water bath at 90 ℃ and vigorous stirring, and adjusting the pH to 10 to obtain a precipitate system; standing the precipitate system in a beaker for 2.65h; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 90 ℃ for 2 hours and 125 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 900 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/Nd 2 O 3 CoO, designated catalyst C-3, and the test results are shown in tables 1 and 2.
Example 4
1.59mol of zirconyl nitrate, 0.04mol of nitric acid tetrahydrateCalcium, 0.0038mol of cerium nitrate and 0.0034mol of nickel nitrate hexahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.53mol L -1 、Ca 2+ The concentration is 0.013mol L -1 、Ce 3+ At a concentration of 0.0013mol L -1 、Ni 2+ At a concentration of 0.0011mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 70 ℃ water bath and vigorous stirring, and adjusting the pH to 10.1 to obtain a precipitate system; standing the sediment system in a beaker for 2.4 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 95 ℃ for 2 hours and 140 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 700 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/CeO 2 NiO, designated catalyst C-4, was tested and the results are shown in tables 1 and 2.
Example 5
1.58mol of zirconyl nitrate, 0.049mol of calcium nitrate tetrahydrate, 0.0079mol of lanthanum nitrate and 0.008mol of copper nitrate trihydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.53mol L -1 、Ca 2+ The concentration is 0.0163mol L -1 、La 3+ The concentration is 0.0026mol L -1 、Cu 2+ The concentration is 0.0027mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of water bath at 65 ℃ and vigorous stirring, and adjusting the pH to 10.2 to obtain a precipitate system; standing the precipitate system in a beaker for 2.7h; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 80 ℃ for 2 hours and at 130 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 600 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/La 2 O 3 CuO, designated catalyst C-5, and the test results are shown in tables 1 and 2.
Example 6
1.62mol of zirconyl nitrate, 0.088mol of calcium nitrate tetrahydrate, 0.002mol of ytterbium nitrate and 0.003mol of zinc nitrate hexahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Ca 2+ At a concentration of 0.029mol L -1 、Yb 3+ The concentration is0.0007mol L -1 、Zn 2+ The concentration is 0.001mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of water bath at 60 ℃ and vigorous stirring, and adjusting the pH to 9.9 to obtain a precipitate system; standing the sediment system in a beaker for 2.3 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 85 ℃ for 2 hours and at 135 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 550 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/Yb 2 O 3 ZnO, designated as catalyst C-6, and the test results are shown in Table 1.
Example 7
1.63mol of zirconyl nitrate, 0.064mol of magnesium nitrate, 0.010mol of cerium nitrate and 0.032mol of nickel nitrate hexahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Mg 2+ The concentration is 0.021mol L -1 、Ce 3+ At a concentration of 0.003mol L -1 、Ni 2+ The concentration is 0.011mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 75 ℃ water bath and intense stirring, and regulating the pH to 10 to obtain a precipitate system; standing the precipitate system in a beaker for 2.8 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, then dried at 90 ℃ for 2 hours, and dried at 140 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 750 ℃ for 2 hours to obtain a sample ZrO 2 /MgO/CeO 2 NiO, designated catalyst C-7, was tested and the results are shown in tables 1 and 2.
Example 8
1.6mol of zirconyl nitrate, 0.077mol of barium nitrate, 0.0006mol of lanthanum nitrate and 0.124mol of copper nitrate trihydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.53mol L -1 、Ba 2+ At a concentration of 0.026mol L -1 、La 3+ At a concentration of 0.0002mol L -1 、Cu 2+ At a concentration of 0.041mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 80 ℃ water bath and vigorous stirring, and adjusting the pH to 10.1 to obtain a precipitate system; the precipitate system was placed in a beakerStanding for 2.9h; then, centrifugal separation was performed, and the obtained precipitate was washed with deionized water to ph=6.5, followed by drying at 90 ℃ for 2 hours, and further drying at 115 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 600 ℃ for 2 hours to obtain a sample ZrO 2 /BaO/La 2 O 3 CuO, designated as catalyst C-8, and the test results are shown in tables 1 and 2.
Example 9
1.59mol of zirconyl nitrate, 0.0008mol of strontium nitrate, 0.09mol of cerium nitrate and 0.0012mol of copper nitrate trihydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.53mol L -1 、Sr 2+ The concentration is 0.0003mol L -1 、Ce 3+ The concentration is 0.03mol L -1 、Cu 2+ At a concentration of 0.0004mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of water bath at 85 ℃ and vigorous stirring, and regulating the pH to be 10.2 to obtain a precipitate system; standing the sediment system in a beaker for 2.2 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 90 ℃ for 2 hours and 125 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 800 ℃ for 2 hours to obtain a sample ZrO 2 /BaO/La 2 O 3 CuO, designated as catalyst C-9, and the test results are shown in tables 1 and 2.
Comparative example 1
A catalyst was prepared in accordance with the method of example 4, except that pseudo-boehmite powder (specific surface area 398m 2 g -1 Pore volume 0.99mL g -1 For every 100g of Al 2 O 3 Calculated powder, sulfur content of 0.85 g) as main component source to obtain sample Al 2 O 3 /CaO/CeO 2 NiO, designated catalyst D-1, was tested and the results are shown in tables 1 and 2.
Comparative example 2
A catalyst was prepared in the same manner as in example 4 except that zirconia powder was used as a main component source to obtain a sample ZrO 2 (powder)/CaO/CeO 2 NiO, designated catalyst D-2, was tested as shown in Table 1 and Table 2.
Comparative example 3
1.62mol of zirconyl nitrate, 0.053mol of calcium nitrate tetrahydrate and 0.034mol of lanthanum nitrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Ca 2+ The concentration is 0.018mol L -1 、La 3+ The concentration is 0.011mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 75 ℃ water bath and vigorous stirring, and adjusting the pH to 10.2 to obtain a precipitate system; standing the sediment system in a beaker for 2.4 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 80 ℃ for 2 hours and at 120 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 500 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/La 2 O 3 Catalyst D-3 was recorded and the test results are shown in tables 1 and 2.
Comparative example 4
A catalyst was prepared in the same manner as in example 1, except that 0.3mol of chromium nitrate nonahydrate was weighed and dissolved in 3L of deionized water to obtain a sample ZrO 2 /CaO/La 2 O 3 /Cr 2 O 3 Catalyst D-4 was identified and the test results are shown in tables 1 and 2.
Comparative example 5
1.62mol of zirconyl nitrate, 0.053mol of calcium nitrate tetrahydrate and 0.002mol of chromium nitrate nonahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、Ca 2+ The concentration is 0.018mol L -1 、Cr 3+ At a concentration of 0.0007mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 75 ℃ water bath and vigorous stirring, and adjusting the pH to 10.2 to obtain a precipitate system; standing the sediment system in a beaker for 2.4 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 80 ℃ for 2 hours and at 120 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 500 ℃ for 2 hours to obtain a sample ZrO 2 /CaO/Cr 2 O 3 Catalyst D-5 was identified and the test results are shown in tables 1 and 2.
Comparative example 6
A catalyst was prepared in the same manner as in example 1, except that 0.12mol of lanthanum nitrate was weighed and dissolved in 3L of deionized water to obtain a sample ZrO 2 /CaO/La 2 O 3 /Cr 2 O 3 Catalyst D-6 was recorded and the test results are shown in tables 1 and 2.
Comparative example 7
1.62mol of zirconyl nitrate, 0.034mol of lanthanum nitrate and 0.002mol of chromium nitrate nonahydrate are dissolved in 3L of deionized water to prepare the zirconium element with the concentration of 0.54mol L -1 、La 3+ The concentration is 0.011mol L -1 、Cr 3+ At a concentration of 0.0007mol L -1 Is a mixed solution of (a) and (b); dropwise adding an ammonia water solution (25 wt%) into the mixture under the conditions of 75 ℃ water bath and vigorous stirring, and adjusting the pH to 10.2 to obtain a precipitate system; standing the sediment system in a beaker for 2.4 hours; then, centrifugal separation is carried out, and the obtained precipitate is washed with deionized water to a pH=6.5, and then dried at 80 ℃ for 2 hours and at 120 ℃ for 2 hours; finally, roasting the dried product in a muffle furnace at 500 ℃ for 2 hours to obtain a sample ZrO 2 /La 2 O 3 /Cr 2 O 3 Catalyst D-7 was identified and the test results are shown in tables 1 and 2.
Comparative example 8
A catalyst was prepared in the same manner as in example 1, except that 0.28mol of calcium nitrate tetrahydrate was weighed and dissolved in 3L of deionized water to obtain a sample ZrO 2 /La 2 O 3 /Cr 2 O 3 Catalyst D-8 was recorded and the test results are shown in tables 1 and 2.
Comparative example 9
A catalyst was prepared in the same manner as in example 1 except that the catalyst was prepared at a calcination temperature of 250℃to give a sample ZrO 2 /CaO/La 2 O 3 /Cr 2 O 3 (250 ℃ C.) denoted as catalyst D-9, and the test results are shown in tables 1 and 2.
Comparative example 10
A catalyst was prepared in the same manner as in example 1 except that the catalyst was prepared at a calcination temperature of 1200℃to give a sampleZrO (R) product 2 /CaO/La 2 O 3 /Cr 2 O 3 (1000 ℃ C.) denoted as catalyst D-10, and the test results are shown in tables 1 and 2.
TABLE 1
Figure BDA0003326222300000171
Figure BDA0003326222300000181
Note that: * the amount refers to the weight of group IIA oxide relative to 100g of catalyst;
** the content refers to the weight of group IIIB oxide relative to 100g of catalyst;
*** the content refers to the weight of transition metal oxide relative to 100g of catalyst.
TABLE 2
Figure BDA0003326222300000182
Note that: * the medium strong acid refers to the percentage content of the amount of the medium strong acid center of the catalyst based on the total amount of the weak acid center and the amount of the medium strong acid center of the catalyst;
** 1.7-2.6nm means that the pore volume with the pore diameter in the range of 1.7-2.6nm accounts for the percentage of the total pore volume of the composite catalyst.
Test example 1
This test example is used to illustrate the process for the preparation of 4-methyl-1-pentene by dehydration of methyl isobutyl carbinol (MIBC).
50mL of the catalyst was weighed and charged into a fixed bed reactor, and preheated at 300℃for 1 hour with nitrogen, methyl isobutyl carbinol was fed into the reaction system by means of a metering pump, and the liquid phase volume space velocity of methyl isobutyl carbinol was 0.3 hour -1 The dehydration reaction is carried out in a reactor, the dehydration reaction temperature is 310 ℃, the reaction pressure is 0.1MPa, and after the reaction is stable (namely, the reaction500 h), the reaction solution was sampled and analyzed, and the analysis results are shown in Table 3.
The sampling analysis method is gas chromatography analysis, and calibration is carried out by preparing a correction factor of a standard sample;
conversion and selectivity were calculated based on the molar content of each component in the reaction liquid (methyl isobutyl carbinol is abbreviated as MIBC, 4-methyl-1-pentene is 4MP1, 4-methyl-2-pentene is 4MP2, and methyl isobutyl ketone is MIBK).
MIBC conversion = 100% -n 1 /[(n 1 +n 2 +n 3 +n 4 )+2×n 5 ]×100％
4MP1 selectivity = n 2 /[(n 2 +n 3 +n 4 )+2×n 5 ]×100％
4MP2 selectivity = n 3 /[(n 2 +n 3 +n 4 )+2×n 5 ]×100％
Wherein n is 1 The molar content of MIBC in the reaction solution; n is n 2 The molar content of 4MP1 in the reaction liquid; n is n 3 The molar content of 4MP2 in the reaction liquid; n is n 4 The molar content of MIBK in the reaction liquid; n is n 5 The molar content of the oligomer in the reaction solution.
4MP1 duty cycle = 4MP 1/(4MP2+4MP1). Times.100%
The 4MP1 ratio is the ratio of 4MP1 selectivity to the sum of 4MP1 and 4MP2 selectivity, i.e. the ratio of alpha-olefin to the sum of alpha-olefin and beta-olefin, indicating that the reaction produces more alpha-olefin, i.e. the selectivity of alpha-olefin is high.
TABLE 3 Table 3
Figure BDA0003326222300000191
Figure BDA0003326222300000201
As can be seen from the data in Table 3, the conversion of catalysts C-1 to C-9 of the present invention was higher than that of comparative catalysts D-1 to D-10.
The catalyst is discharged for characterization after continuous reaction for 1800 hours, and the results show that the carbon deposition amounts of the catalysts C-1 to C-9 prepared by the embodiment of the invention are all lower than 2wt%; whereas the catalysts D-1 to D-10 prepared in the comparative examples had carbon deposition amounts of 3.8 to 10% by weight; the catalysts C-1 to C-9 prepared by the embodiment of the invention have better stability and less carbon deposition.
After the catalysts C-1 to C-9 are subjected to catalytic reaction for 1800 hours, the conversion rate and the selectivity are not obviously changed compared with those of the catalysts at 500 hours; the conversion rate of MIBC is reduced by not more than 1.5%, and the reduction value of the 4MP1 ratio is not more than 1%; the conversion rate and the 4MP1 ratio of the catalyst are obviously reduced by 14-36% when the catalyst is used for catalyzing the reaction for 1800 hours from D-1 to D-10, and the reduction value of the 4MP1 ratio is 20% -50% compared with the conversion rate and the 4MP1 ratio of the catalyst at 500 hours; the catalyst prepared by the embodiment of the invention has longer service life.
Test example 2
This test example is used to illustrate the process for preparing 1-pentene by dehydration of 2-pentanol.
50mL of the catalyst of example 4 was weighed and charged into a fixed bed reactor, preheated with nitrogen at 300℃for 1 hour, and 2-pentanol was fed into the reaction system by a metering pump, the liquid phase volume space velocity of 2-pentanol being 0.4 hour -1 The dehydration reaction was carried out in the reactor at 310℃and 0.1MPa, and after the reaction was stabilized (i.e., 500 hours of reaction), the reaction solution was sampled and analyzed, and the analysis results are shown in Table 4.
The sampling analysis method is gas chromatography analysis, and calibration is carried out by preparing a correction factor of a standard sample; conversion and selectivity were calculated as the molar content of each component in the reaction solution.
2-pentanol conversion = 100% -w 1 /[(w 1 +w 2 +w 3 )+2×w 4 ]×100％
1-pentene selectivity = w 2 /[(w 2 +w 3 )+2×w 4 ]×100％
2-pentene selectivity = w 3 /[(w 2 +w 3 )+2×w 4 ]×100％
w 1 The molar content of 2-amyl alcohol in the reaction liquid; w (w) 2 Is a reaction liquidMolar content of 1-pentene; w (w) 3 The molar content of 2-pentene in the reaction liquid; w (w) 4 The molar content of the oligomer in the reaction solution.
1-pentene ratio=1-pentene/(2-pentene+1-pentene) ×100%
The ratio of 1-pentene to the sum of 1-pentene and 2-pentene selectivity, i.e., the ratio of alpha-olefin to the sum of alpha-olefin and beta-olefin, indicates that the reaction product has more alpha-olefin, i.e., the selectivity of alpha-olefin is high.
TABLE 4 Table 4
Reaction time 2-pentanol conversion% 1-pentene ratio%
500h 92.52 90.3
1800h 92.47 89.9
As can be seen from Table 4, in the reaction of preparing 2-pentene by catalyzing 2-pentanol to dehydrate, the conversion rate of 2-pentanol is up to 92.52%, the selectivity of 1-pentene is up to 90.3%, and after 1800 hours of the catalytic reaction, the conversion rate of 2-pentanol and the selectivity of 1-pentene are not obviously changed compared with 500 hours, which indicates that the catalyst obtained by the embodiment of the invention has long service life.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims (11)

1. A catalyst for the dehydration of alcohols to alpha-olefins, said catalyst comprising, based on the total amount of said catalyst: 84-99.88wt% of main component, 0.04-6wt% of IIA oxide, 0.05-8wt% of IIIB oxide and 0.03-10wt% of transition metal oxide;
wherein the main component is selected from at least one of IVB-group oxides;
the transition metal oxide is selected from at least one of group VIB oxide, group VIII oxide, group IB oxide and group IIB oxide.
2. The catalyst of claim 1, wherein the catalyst comprises, based on the total amount of the catalyst: 89-99.68wt% of a main component, 0.1-4wt% of a group IIA oxide, 0.12-3.5wt% of a group IIIB oxide, and 0.1-3.5wt% of a transition metal oxide;
Preferably, the weight ratio of the group IIA oxide, the group iiib oxide and the transition metal oxide is 0.2 to 20:0.4-10:1, a step of; preferably 0.3-6:0.5-5:1.
3. the catalyst of claim 1 or 2, wherein the group ivb oxide is selected from zirconium oxide;
preferably, the group IIA oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide, and barium oxide;
preferably, the group IIIB oxide is selected from at least one of lanthanum oxide, cerium oxide, ytterbium oxide, neodymium oxide and praseodymium oxide;
preferably, the transition metal oxide is selected from at least one of chromium oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, and silver oxide.
4. A catalyst according to any one of claims 1 to 3, wherein in the catalyst, pore volume in the range of 1.7 to 2.6nm accounts for 65% or more, preferably 70 to 90% of the total pore volume of the catalyst;
preferably, the pore volume of the catalyst is 0.08-0.2 mL.g -1 ；
Preferably, the specific surface area of the catalyst is 40-120m 2 ·g -1 。
5. The catalyst according to any one of claims 1-4, wherein the CO of the catalyst 2 The adsorption quantity is 0.15-0.33 mmol.g -1 ；
Preferably, the amount of mid-strongly acidic centres of the catalyst is less than 45%, preferably less than 25%, based on the total of the amount of weakly acidic centres and the amount of mid-strongly acidic centres of the catalyst.
6. A method of preparing a catalyst for the dehydration of alcohols to alpha-olefins, the method comprising: the main component source, IIA group salt, IIIB group salt and transition metal salt are mixed according to the mole ratio of 1:0.0001-0.1:0.0001-0.1: mixing 0.0001-0.1 in solvent to obtain mixed solution; then, the mixed solution is contacted with a precipitator for coprecipitation reaction, and the obtained reaction product is aged; then roasting the aged product;
wherein the main component is selected from at least one of IVB-group metal sources;
the transition metal salt is selected from one of a group VIB salt, a group VIII salt, a group IB salt and a group IIB salt.
7. The method of claim 6, wherein the main component source is selected from a zirconium source, preferably at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate;
preferably, the precipitant is selected from at least one of ammonia, urea, sodium hydroxide and sodium carbonate.
8. The method of claim 6 or 7, wherein the aging conditions comprise: the temperature is 50-90 ℃ and the time is 1-9h;
Preferably, the roasting conditions include: the temperature is 500-1100 ℃ and the time is 2-20h.
9. A catalyst for the preparation of alpha-olefins by dehydration of alcohols prepared by the method of any one of claims 6 to 8.
10. A process for the dehydration of an alcohol to produce an α -olefin, the process comprising: contacting an alcohol with the catalyst for producing alpha-olefin by dehydration of an alcohol according to any one of claims 1 to 5 and 9 in the presence or absence of a carrier gas to carry out dehydration reaction;
preferably, the conditions of the dehydration reaction include: the temperature is 240-370 ℃, preferably 250-350 ℃; the pressure is 0.085-0.25MPa; the volume space velocity of the liquid phase is 0.1 to 0.8h -1 Preferably 0.15-0.6h -1 ；
Preferably, when the carrier gas is present, the flow rate of the carrier gas is 15-45mL min -1 Preferably 18-38mL min -1 。
11. The method of claim 10, wherein the alcohol is selected from C 2 -C 18 An alcohol of (a);
preferably, the alcohol is selected from at least one of 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-undecanol, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-hexadecanol, 2-heptadecanol, 2-octadecanol.
CN202111262338.0A 2021-10-28 2021-10-28 Catalyst for preparing alpha-olefin by alcohol dehydration, preparation method thereof and method for preparing alpha-olefin by alcohol dehydration Pending CN116037098A (en)

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