CN110560042B

CN110560042B - Method for preparing propylene by propane dehydrogenation

Info

Publication number: CN110560042B
Application number: CN201810566764.5A
Authority: CN
Inventors: 吴省; 缪长喜; 洪学思; 姜冬宇
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2018-06-05
Filing date: 2018-06-05
Publication date: 2021-10-01
Anticipated expiration: 2038-06-05
Also published as: CN110560042A

Abstract

The invention relates to a method for preparing propylene by propane dehydrogenation, which mainly solves the problem of low activity of Cr-series dehydrogenation catalysts prepared by the prior art. The method adopts the direct contact reaction of a propane raw material and a catalyst to obtain propylene, and is characterized in that the reaction pressure is 0.01-1 MPa, the temperature is 520-650 ℃, and the mass space velocity is 0.2-8 h^‑1(ii) a The catalyst comprises the following components in parts by weight: a) 1-30 parts of Cr and/or W element or oxide thereof; b) 0.01-5 parts of at least one element selected from IVB group of the periodic table or its oxide; c) 69-96 parts of alumina carrier, the problem is solved well, and the method can be used for industrial application of propane dehydrogenation.

Description

Method for preparing propylene by propane dehydrogenation

Technical Field

The invention relates to a method for preparing propylene by propane dehydrogenation.

Background

Propylene has wide application, and is also used for producing acrylonitrile, propylene oxide, acrylic acid, isopropanol and the like besides polypropylene, but the increase of the demand of the polypropylene is always the key of the increase of the demand of the propylene. The annual growth rate of propylene is expected to be kept at 5% in the future, in order to enable the propylene yield to meet the requirements of downstream derivatives, the method for preparing propylene by adopting ethylene co-production and light oil (naphtha and light diesel oil) cracking technology cannot meet the growth of the demand, the catalytic dehydrogenation process is a commonly used preparation method for preparing low-carbon olefins at present, low-carbon alkanes are generally used for preparing corresponding olefins by dehydrogenation, wherein propylene is obtained by dehydrogenation of corresponding propane, and therefore, the method for preparing propylene by taking propane as a raw material for dehydrogenation reaction is vigorously developed in various countries in the world. The propane dehydrogenation reaction is a strong endothermic reaction and is limited by thermodynamic equilibrium, so that a relatively ideal propylene yield can be obtained under the conditions of low pressure and high temperature, and the problems of poor catalyst performance, low selectivity and the like caused by the aggravation of propane cracking reaction and deep dehydrogenation due to excessively high reaction temperature.

The industrial propane dehydrogenation technology mainly comprises a Pt catalyst and a Cr catalyst, and comprises an Oleflex process of UOP, a Catofin process of Lummus, a STAR process of Uhde, a PDH process of Linde, an FBD process developed by Snamprogetti-Yarsintez cooperation and the like, wherein the industrial devices are mostly the Oleflex technology and the Catofin technology, and the catalysts applied to the Oleflex technology and the Catofin technology are respectively the Pt catalyst and the Cr catalyst. The Pt dehydrogenation catalyst is used for dehydrogenation of low-carbon alkane, has the advantages of environmental friendliness, high activity and the like, and has high price, complex preparation and high requirement on purity of reaction raw materials. The Cr catalyst has low price, relatively high activity and low requirement on the purity of raw materials, but has certain influence on the environment, frequent regeneration is needed in the reaction process, the regeneration and other conditions are harsh, and the performance requirements on all aspects of the Cr catalyst are higher.

Chinese patent CN103769156 uses ammonia treated alumina as carrier, Cr as active component, potassium, manganese, cobalt, iron, nickel and the like as auxiliary agent, and prepares dehydrogenation catalyst by co-impregnation method, the Cr content is 2-6%, the auxiliary agent content is 0.1-5%, the catalyst has better selectivity, but the activity is relatively low. The dehydrogenation catalyst disclosed in the Chinese patent CN100406415C has a chromium oxide content of 5-30%, and the actual chromium oxide content in example 1 is about 24%, which belongs to a high Cr content catalyst. Chinese patent CN 102019178A reports a catalyst for preparing propylene by propane dehydrogenation, and preparation and application thereof, wherein the content of chromium oxide is 10-20%, the reaction temperature is 590 ℃, the absolute pressure is 0.105MPa, and the space velocity is 900 hours^-1Under the condition, the conversion rate of propane is 40% and the selectivity of propylene is 85% when the reaction is carried out for 5 min. Chinese patent CN101940922A reports a low-carbon alkane dehydrogenation catalyst, which takes Cr as an active component and alkali metal as an auxiliary agent, and the reaction temperature is 645 ℃ and the liquid hourly space velocity is 600 hours^-1The conversion of propane at atmospheric pressure for 30 minutes was 47%, and propylene was recoveredThe selectivity was about 89%. Although the catalyst has better activity, the content of the chromium oxide is up to 10-45% by weight of the catalyst, which undoubtedly puts higher requirements on environmental protection.

Although the propane dehydrogenation catalyst has been developed, the catalyst still has problems of low activity, especially the selectivity and stability of the existing Cr-based dehydrogenation catalyst are also insufficient. W has more applications in the petrochemical industry, and can enable the catalyst to have better catalytic activity and selectivity through the synergistic effect with Cr. According to the invention, Cr and/or W are used as the active components of the catalyst, and the IVB group of the periodic table of elements is added in the preparation process, and the result shows that the propane dehydrogenation catalyst prepared by the method has high catalyst activity and good industrial application prospect.

Disclosure of Invention

One of the technical problems to be solved by the invention is the problem of low activity of the propane dehydrogenation catalyst in the prior art, and provides a method for preparing propylene by propane dehydrogenation. The second technical problem to be solved by the present invention is to provide a method for preparing a catalyst corresponding to the first technical problem.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: a method for preparing propylene by propane dehydrogenation comprises the step of directly contacting and reacting a propane raw material with a catalyst to obtain propylene, and is characterized in that the reaction pressure is 0.01-1 MPa, the temperature is 520-650 ℃, and the mass space velocity is 0.2-8 h^-1(ii) a The catalyst comprises the following components in parts by weight:

a) 1-30 parts of Cr and/or W element or oxide thereof;

b) 0.01-5 parts of at least one element selected from IVB group of the periodic table or its oxide;

c) 69-96 parts of Al₂O₃And (3) a carrier.

In the technical scheme, the parts of Cr and/or W elements or oxides thereof are 5-23 parts by weight of the propane catalyst.

In the technical scheme, the parts of Cr and/or W elements or oxides thereof are 10-18 parts by weight of the propane catalyst.

In the above technical solution, it is more preferable that the alloy simultaneously includes Cr and W elements or oxides thereof, wherein the weight ratio of Cr to W element is: (0.1-10): 1. in this case, the use of both Cr and W has an unexpected synergistic effect in improving the catalytic activity of the propane dehydrogenation catalyst.

In the above technical solution, preferably, the alloy simultaneously includes Cr and W elements or oxides thereof, wherein the weight ratio of Cr to W elements is: (0.25-4): 1.

in the technical scheme, the part of the element selected from IVB group of the periodic table or the oxide thereof is 0.01-3 parts by weight of the propane catalyst, wherein the element of IVB group is selected from at least one of Ti and Zr.

In the technical scheme, the range of the IVB group element or the oxide thereof in the periodic table is 0.3-3 parts by weight of the propane catalyst.

In the above technical solution, it is more preferable that the group ivb element of the periodic table or the oxide thereof is a mixture of Ti and Zr.

In the above technical solution, more preferably, the group ivb element of the periodic table or an oxide thereof is a mixture of Ti and Zr, where Ti: the weight ratio of Zr is (0.25-5): 1, and the mixture of Ti and Zr has unexpected synergistic effect on the aspect of improving the catalyst activity of the propane dehydrogenation catalyst.

The Cr element and the W element are used together and cooperate with the IVB element, so that the catalyst has unexpected synergistic effect on the aspect of improving the catalyst activity of the propane dehydrogenation catalyst.

In the technical scheme, the specific surface of the adopted alumina carrier is 50-500 m²(g) the pore diameter is 5-40 nm.

In the technical scheme, more preferably, the specific surface range of the alumina carrier is 117-350 m²The pore diameter is 8-25 nm.

To solve the second technical problem, the invention adopts the following technical scheme: a method of preparing a catalyst for propane dehydrogenation comprising the steps of:

a) pressing and screening the alumina with certain specific surface area and aperture, selecting 20-40 meshes for screening, and roasting at 400-600 ℃ for 0.5-12 hours to obtain a pretreated carrier I;

b) mixing a carrier I with a soluble salt solution containing Cr and/or W and a soluble solution in the IVB group of the periodic table to obtain a mixture I, and adjusting the pH value of the mixture I to 1-7 by using an inorganic ammonia or inorganic ammonium salt solution at the temperature of 10-80 ℃ to obtain a mixture II;

c) and (3) soaking the mixture II for 0.5-8 hours at the temperature of 10-100 ℃, filtering, drying, and roasting at 300-800 ℃ for 0.5-12 hours to obtain the required propane dehydrogenation catalyst.

The soluble salt of Cr can be selected from one of nitrate, acetate or oxalate; the W soluble salt is selected from tungstate, metatungstate or acetate. Ti and Zr are selected from one of nitrate, acetate and other soluble salts.

In the technical scheme, the preferable scheme of the inorganic ammonia or inorganic ammonium salt is selected from ammonia water, ammonium carbonate or ammonium bicarbonate, and the preferable range of the pH value of the solution is 1-7, and the more preferable range is 1-3; the preferable range of the dipping temperature is 50-80 ℃, the preferable range of the dipping time is 1-3 hours, the preferable range of the roasting temperature of the catalyst is 400-600 ℃, and the preferable range of the roasting time is 4-8 hours.

The method for producing propylene of the invention focuses on the reaction section, and propane is converted into propylene through the catalyst bed. The fresh propane feed is combined with propane recycle from the bottoms of the product separation column and the de-oiling column overhead as feed to the reactor. The raw material is heated and gasified by steam and a heat exchanger, and the heated and gasified material is heated to the reaction temperature in a feeding heating furnace and then sent to a reactor. The hot discharge material of the reactor is cooled after heat exchange with the raw material of the reactor, and is sent to the compression section of the device. The propane is maintained at a negative pressure in the reactor and while the system is still under vacuum conditions, the reactor is thoroughly purged with steam, thereby sweeping the catalyst and residual hydrocarbons from the reactor and entering the recovery section. The regeneration air is provided by a regeneration air turbine or air compressor which is preheated early in the air heater before entering the reactor. The regeneration air, in addition to serving to burn the catalyst to remove coke, is also used to restore the bed temperature to the initial operating conditions. During regeneration, heat is supplemented by controlled injection of fuel gas, which is combusted within the catalyst bed. When the regeneration is completed, the reactor is pumped to vacuum again, and the next operation cycle is entered.

In a laboratory, the reaction raw material is propane, the reaction pressure is 0.01-1 MPa, the temperature is 520-650 ℃, and the mass space velocity is 0.2-8 h^-1(ii) a The reaction raw material and the catalyst are directly contacted and reacted to obtain the propylene. The catalyst prepared by the method is subjected to activity evaluation in an isothermal fixed bed reactor, and the process for preparing propylene by propane dehydrogenation comprises the following steps:

the flow rate of propane gas is adjusted through a mass flow meter, the propane gas enters a preheating zone to be preheated, then the propane gas enters a reaction zone, a heating section and a reaction section of a reactor are heated by electric heating wires to reach a preset temperature, and the length of a reaction tube of the reactor is about 400-580 mm, wherein the inner diameter of the reaction tube is phi 9 mm-phi 6 mm. The reacted gas was passed through a condensing pot and then analyzed for composition by gas chromatography. The conversion rate of the propane is obtained by multiplying the content of the propane which accounts for the sum of the contents of all gas-phase products after the reaction by 100 percent; selectivity of olefin as a percentage of propylene content in other gas components than propane after reaction, i.e. propylene content divided by C₁、C₂、C₄And the percentage of the sum of the propylene contents.

The activity and selectivity of dehydrogenation reaction of propane dehydrogenation Cr series catalyst are related to catalyst components, and the technological condition in the operation process has great influence on the dehydrogenation reaction. Cr and/or W are added together, and the IVB element is added, so that the acid-base characteristics, the surface characteristics and the like of the surface of the catalyst can be changed, and the catalyst has higher activity. When the catalyst obtained by adopting the preparation conditions is used in the propane dehydrogenation reaction, the propane conversion rate is 43 percent, the propylene selectivity is 90.9 percent, and the technical effect of preparing propylene by propane dehydrogenation is better.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

52.66 g of chromium nitrate and 3.78 g of sodium titanate were weighed and added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²Adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water for the alumina carrier with the pore diameter of 15nm per gram, soaking the alumina carrier in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at the temperature of 550 ℃ for 4 hours to obtain the required catalyst.

The flow of propane gas is regulated by a mass flow meter, the propane gas enters a preheating zone for preheating, and then enters a reaction zone, a heating section and a reaction section of the reactor are heated by electric heating wires to reach a preset temperature, and the reactor is a quartz tube with the inner diameter of phi 6mm and the length of 400 mm. The reacted gas was passed through a condensing pot and then analyzed for composition by gas chromatography.

The catalyst evaluation conditions in the isothermal fixed bed reactor were as follows: 0.5 g of the catalyst is loaded into the isothermal fixed bed reactor, the reaction pressure is normal pressure, and the gas mass space velocity is 1.0 hour^-1And the reaction temperature is 580 ℃. The results are shown in Table 1.

[ example 2 ]

52.66 g of chromium nitrate and 3.78 g of sodium titanate were weighed and added to 100 ml of deionized water, and 87 g of a solution having a specific surface area of 340m was added²Adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water for the alumina carrier with the pore diameter of 9nm, soaking the alumina carrier in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 3 ]

52.66 g of chromium nitrate and 3.78 g of sodium titanate were weighed and added to 100 ml of deionized water, and 87 g of a specific surface area 173m was added²Alumina carrier with 12nm pore diameter, regulating pH value to 3.5 with 2.5% ammonia water, and soaking in 80 deg.C water bath for 1 hrAnd (3) taking out the sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 4 ]

52.66 g of chromium nitrate and 3.78 g of sodium titanate were weighed and added to 100 ml of deionized water, and 87 g of a solution having a specific surface area of 45m was added²Adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water for the alumina carrier with the aperture of 28nm per gram, then soaking the alumina carrier in a water bath with the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven with the temperature of 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample for 4 hours at the temperature of 550 ℃ to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 5 ]

52.66 g of chromium nitrate and 10.44 g of zirconium nitrate were weighed and added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 6 ]

Ammonium tungstate 10.94 g and sodium titanate 3.78 g were weighed into 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and as a resultSee table 1.

[ example 7 ]

Ammonium tungstate 10.94 g and zirconium nitrate 10.44 g were weighed into 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 8 ]

52.66 g of chromium nitrate, 1.89 g of sodium titanate and 5.22 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 9 ]

52.66 g of chromium nitrate, 1.26 g of sodium titanate and 6.96 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 7 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 10 ]

31.44 g of chromium oxalate, 7.40 g of titanium nitrate and 3.48 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²Alumina carrier with pore diameter of 15nm and 2.5% ammoniaAdjusting the pH value of the solution to 5 by water, then soaking the solution in water bath at 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample at 550 ℃ for 4 hours to obtain the required catalyst. The prepared catalyst was charged into a fixed bed reactor, and activity evaluation was performed at 550 ℃ and the results are shown in table 1.

[ example 11 ]

Ammonium tungstate 10.94 g, sodium titanate 1.89 g and zirconium nitrate 5.22 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 7 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 12 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 13 ]

Ammonium tungstate 10.94 g, sodium titanate 2.52 g and zirconium acetate 2.66 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 14 ]

26.33 g of chromium nitrate, 2.59 g of tungsten acetate and 3.78 g of sodium titanate were weighed into 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 15 ]

13.17 g of chromium nitrate, 2.73 g of ammonium tungstate and 3.78 g of sodium titanate were weighed into 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 16 ]

60.57 g of chromium nitrate, 12.54 g of ammonium tungstate and 3.78 g of sodium titanate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 17 ]

39.5 g of chromium nitrate, 8.18 g of ammonium tungstate and 3.78 g of sodium titanate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²Adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking in 50 ℃ water bath for 1 hour, taking out a sample, filtering, drying in a 120 ℃ oven for 8 hours, putting the sample into a muffle furnace, and roasting at 550 ℃ for 4 hours to obtain the alumina carrier with the pore diameter of 15nmTo the desired catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 18 ]

47.4 g of chromium nitrate, 9.81 g of ammonium tungstate and 3.78 g of sodium titanate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 19 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate and 10.44 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 20 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate, 1.89 g of sodium titanate and 5.22 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 21 ]

42.13 g of chromium nitrate, 2.19 g of ammonium tungstate, 1.89 g of sodium titanate and 5.22 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²Alumina carrier with 15nm pore diameter and 2.5% ammonia waterThe pH value is 3.5, then the sample is immersed in a water bath at 50 ℃ for 1 hour, then the sample is taken out and filtered, the sample is dried in a 120 ℃ oven for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, thus obtaining the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 22 ]

10.53 g of chromium nitrate, 8.75 g of ammonium tungstate, 1.89 g of sodium titanate and 5.22 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 23 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate, 1.26 g of sodium titanate and 6.96 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 24 ]

42.13 g of chromium nitrate, 2.19 g of ammonium tungstate, 1.26 g of sodium titanate and 6.96 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 25 ]

10.53 g of chromium nitrate, 8.75 g of ammonium tungstate, 1.26 g of sodium titanate and 6.96 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 26 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate, 2.52 g of sodium titanate and 3.48 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 27 ]

42.13 g of chromium nitrate, 2.19 g of ammonium tungstate, 2.52 g of sodium titanate and 3.48 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 28 ]

10.53 g of chromium nitrate, 8.75 g of ammonium tungstate, 2.52 g of sodium titanate and 3.48 g of zirconium nitrate were weighed and added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with the pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and drying againThe sample is put into a muffle furnace to be roasted for 4 hours at the temperature of 550 ℃, and the required catalyst is obtained. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 29 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate, 0.53 g of sodium titanate and 8.7 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 30 ]

42.13 g of chromium nitrate, 2.19 g of ammonium tungstate, 0.53 g of sodium titanate and 8.7 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 31 ]

10.53 g of chromium nitrate, 8.75 g of ammonium tungstate, 0.53 g of sodium titanate and 8.7 g of zirconium nitrate were weighed and added to 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 32 ]

26.33 g of chromium nitrate, 5.47 g of ammonium tungstate, 3.15 g of sodium titanate, and 1.74 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and then added87 g specific surface area 117m²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 33 ]

42.13 g of chromium nitrate, 2.19 g of ammonium tungstate, 3.15 g of sodium titanate and 1.74 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 34 ]

10.53 g of chromium nitrate, 8.75 g of ammonium tungstate, 3.15 g of sodium titanate and 1.74 g of zirconium nitrate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The evaluation conditions were the same as in example 1, and the results are shown in Table 1.

[ example 35 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions:normal pressure and 520 ℃ of temperature; the mass space velocity of the propane is 1.0h^-1. The results are shown in Table 2.

[ example 36 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: normal pressure and 620 ℃ of temperature; the mass space velocity of the propane is 1.0h^-1. The results are shown in Table 2.

[ example 37 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: normal pressure and 650 ℃ of temperature; the mass space velocity of the propane is 1.0h^-1. The results are shown in Table 2.

[ example 38 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: the pressure is 1MPa, and the temperature is 620 ℃; the mass space velocity of the propane is 1.0h^-1. The results are shown in Table 2.

[ example 39 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: the pressure is 0.05MPa, and the temperature is 620 ℃; the mass space velocity of the propane is 1.0h^-1. The results are shown in Table 2.

[ example 40 ]

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: normal pressure and 620 ℃ of temperature; the mass space velocity of the propane is 0.2h^-1. The results are shown in Table 2.

[ example 41 ] to provide a pharmaceutical composition

Ammonium tungstate 10.94 g, sodium titanate 1.26 g and zirconium acetate 5.32 g were weighed into 100 ml of deionized water, and 87 g of specific surface area 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. The propane raw material reacts with the catalyst under the following conditions: normal pressure and 620 ℃ of temperature; the mass space velocity of the propane is 8h^-1. The results are shown in Table 2.

Comparative example 1

42.13 grams of chromium nitrate was weighed,2.19 g of ammonium tungstate, 100 ml of deionized water, 87 g of specific surface area 117m²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 2

10.94 g of ammonium tungstate was weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 3

52.66 g of chromium nitrate, 0.68 g of sodium carbonate and 3.03 g of ferric nitrate were weighed into 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 3.5 by using 2.5% ammonia water, soaking in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 4

10.53 g of chromium nitrate and 8.75 g of ammonium tungstate were weighed, added to 100 ml of deionized water, and 87 g of a specific surface area of 117m was added²Alumina carrier with pore diameter of 15nm, regulating pH value of the solution to 3.5 with 2.5% ammonia water, soaking in 50 deg.C water bath for 1 hr, taking out sample, filtering, and oven drying at 120 deg.CDrying for 8 hours, and then putting the sample into a muffle furnace to be roasted for 4 hours at the temperature of 550 ℃ to obtain the required catalyst. The propane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

TABLE 1

[ examples 35 to 41 ]

The catalyst prepared in example 12 was used for propane dehydrogenation, and the reaction conditions and evaluation results are shown in Table 2.

TABLE 2

Claims

1. A method for preparing propylene by propane dehydrogenation comprises the step of directly contacting and reacting a propane raw material with a catalyst to obtain propylene, and is characterized in that the reaction pressure is 0.01-1 MPa, the temperature is 520-650 ℃, and the mass space velocity is 0.2-8 h^-1(ii) a The catalyst comprises the following components in parts by weight:

a) 1-30 parts of oxides of two elements of Cr and W;

b) 0.01-5 parts of a mixture of oxides of two elements of Ti and Zr in the IVB group of the periodic table;

c) 69-96 parts of Al₂O₃And (3) a carrier.

2. The method for preparing propylene by propane dehydrogenation according to claim 1, wherein the amount of the oxide of Cr and W is 5-23 parts by weight based on the weight of the catalyst.

3. The method for preparing propylene by propane dehydrogenation according to claim 2, wherein the weight ratio of Cr to W in the catalyst is as follows: (0.1-10): 1.

4. the method for producing propylene by dehydrogenation of propane according to claim 1, wherein the amount of the mixture of oxides of two elements, Ti and Zr, in group IVB of the periodic Table is 0.01 to 3 parts by weight based on the weight of the catalyst.

5. The method for producing propylene by dehydrogenation of propane according to claim 4, wherein the amount of the mixture of oxides of two elements, Ti and Zr, in group IVB of the periodic Table is 0.3 to 3 parts by weight based on the weight of the catalyst.

6. The method for producing propylene by dehydrogenation of propane according to claim 4, wherein in the catalyst, the molar ratio of Ti: the weight ratio of Zr is (0.25-5): 1.

7. The method for producing propylene by dehydrogenation of propane according to claim 1, wherein Al is₂O₃The specific surface area of the carrier is 50-500 m²The pore diameter is 5-40 nm.

8. The method for producing propylene by dehydrogenation of propane according to claim 7, wherein Al is₂O₃The specific surface area of the carrier is 117-350 m²The pore diameter is 8-25 nm.

9. The method for producing propylene by dehydrogenation of propane according to any one of claims 1 to 8, wherein the method for producing the catalyst comprises the steps of:

a) al with a certain specific surface area and aperture₂O₃Tabletting and screening the carrier, selecting 20-40 meshes for screening, and carrying out 400-600 ℃ treatmentRoasting for 0.5-12 hours to obtain a pretreated carrier I;

b) mixing a carrier I with a required amount of soluble solution containing Cr and W and soluble solution in IVB group of the periodic table of elements to obtain a mixture I, and adjusting the pH value of the mixture I to 1-7 by using inorganic ammonia or inorganic ammonium salt solution at the temperature of 10-80 ℃ to obtain a mixture II;

c) and (3) soaking the mixture II for 0.5-8 hours at the temperature of 10-100 ℃, filtering, drying, and roasting at 300-800 ℃ for 0.5-12 hours to obtain the required catalyst.