Method for preparing propylene and acetone by oxidative activation of propane

Abstract

A catalyst for oxidative activation of propane comprises active components and a carrier, the active components are Mo and V elements, and the carrier is selected from one or a combination of more than one of Al2O3, SiO2, kaolin, clay, talc, diatomite, aluminum silicate, magnesium silicate, MgO, CaO and La2O3. The catalyst is applied to preparation of acetone and propylene from propane, propane can be converted into acetone and propylene, and the content of a deep oxidation product COx is low.

Description

Technical Field

[0001] The present application relates to a catalyst, specifically, to a catalyst for oxidative activation of alkanes to prepare olefins and its application. Background Art

[0002] Propane is a common industrial gas, primarily sourced domestically from refinery byproducts and associated gas from oil fields. Reducing carbon emissions and optimizing resource and energy utilization have been key trends in the chemical industry in recent years. The advancement of integrated refining and chemical production will generate significant light alkane resources. As a low-cost, widely available light alkane feedstock, propane is a promising area of ​​research for its direct synthesis into high-value chemical products.

[0003] The traditional propane dehydrogenation process (PDH) is an endothermic process with high energy consumption, requiring high temperatures to produce propylene as a by-product. High temperatures, resulting in high energy consumption, carbon deposition, and catalyst deactivation, are factors limiting the further development of this method. The oxidative dehydrogenation of propane (ODH) process can effectively address this high energy consumption issue. However, the presence of gaseous oxygen in the ODH process makes the intermediates more susceptible to oxidation, producing undesirable oxidation products. Furthermore, since the mixing of oxygen and propane produces explosive gases, the ODH process places strict demands on reaction conditions and catalyst structure.

[0004] There are currently many catalytic systems for the oxidative dehydrogenation of propane. For example, Cr-based catalysts, V-based catalysts, and B-based catalysts. Chinese Patent Application Publication No. CN106964392 synthesized a Cr-based catalyst. By loading Cr and B on a molecular sieve and adding an alkali metal for modification, when the alkali metal is Na, a maximum propylene selectivity of 75% and a propane conversion rate of 43% were obtained. Chinese Patent Application Publication No. CN115582109A synthesized a B-based catalyst. The active components are B and Mg oxides. At 520°C, the catalyst oxidatively activates propane. Chinese Patent Application Publication No. CN113908823 synthesized a vanadium-based catalyst. Using alumina as a carrier and vanadium pentoxide as an active component, sodium oxide was added as an additive to achieve a propylene selectivity of 87.7%, and the propane conversion rate reached 32.4%.

[0005] The common challenge of almost all reactions of selective oxidation and activation of light alkanes to prepare intermediates is to prevent the deep oxidation of the target product. However, due to the presence of functional groups in the target product, it is often more active than the raw alkane. The propane-based oxidation activation process is a very attractive way to utilize abundant propane resources. However, the propane oxidation activation method to prepare propylene and oxygenated compounds still has many problems if it is applied to industrial production. For example, the MoVTeNbO proposed by Mitsubishi Corporation of Japan in the European patent EP0608838 in the 1990s x The catalyst has good effects in the oxidative dehydrogenation of ethane, the selective oxidation of propane to acrylic acid, and the ammoxidation of propane to acrylonitrile. It is an effective catalyst for the oxidation and activation of light alkanes to produce intermediates. For this type of metal oxide catalyst system, the reaction pathway is generally that propane is activated to open the CH bond to produce propylene, followed by further oxidation of propylene to produce oxygenated compounds such as acrylic acid, and then deep oxidation to produce CO x .

[0006] Acetone is another highly valuable substance, primarily used industrially as a solvent in the manufacture of explosives, plastics, rubber, fibers, leather products, oils, greases, spray paints, and other products. It is also a key raw material for the synthesis of various chemical products. Currently, most acetone is produced via the cumene oxidation process, which involves the reaction of propylene with benzene to form cumene, the oxidation of cumene to form cumene hydroperoxide, and the catalytic decomposition of cumene hydroperoxide to produce phenol and acetone. Numerous patents exist for the cumene process.

[0007] Current research on the direct oxidation of propane to produce acetone suffers from low propane conversion and product yield. Chinese Patent Application Publication No. CN114054021A proposes a method for catalytically dehydrogenating propane to produce acetone using a Cu / TiO2 catalyst under photothermal synergy. However, this method requires relatively stringent conditions and produces low yields, making it difficult to commercialize. Summary of the Invention

[0008] One object of the present application is to provide a catalyst for propane oxidation activation, which can improve the selectivity of propylene and acetone when acting at a certain temperature.

[0009] Another object of the present application is to provide a method for preparing acetone and propylene from propane, which uses a specific catalyst to convert propane into acetone and propylene at a relatively low temperature, and the deep oxidation product CO x The content is low.

[0010] On the one hand, a catalyst for propane oxidation activation includes an active component, an M2 metal and a carrier, wherein the active components are Mo and V elements, and the M2 metal is selected from one or a mixture of two or more of the elements Li, Na, K, Cs, Mg, Ca, Sr, and Ba.

[0011] The catalyst is used for the oxidation activation of propane to produce propylene and acetone, which can improve the selectivity of propylene and acetone and also has a relatively high conversion rate of propane.

[0012] On the other hand, a method for preparing acetone and propylene from propane comprises the following steps: propane undergoes an oxidative activation reaction with an oxidant in the presence of the above-mentioned catalyst at a temperature range of 200 to 400° C. to produce propylene and acetone.

[0013] In the reaction process, the reaction conditions are simple and suitable for industrial production, the selectivity of propylene and acetone is high, and the single-pass conversion rate of propane is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention relates to the stability of the catalyst in the alkane oxidation activation reaction system. DETAILED DESCRIPTION

[0015] The following is a detailed description of a propane oxidation activation catalyst of the present application. This does not limit the scope of protection of the present application, which is defined by the claims. Certain specific details are disclosed to provide a comprehensive understanding of each disclosed embodiment. However, those skilled in the relevant art will appreciate that embodiments may be implemented without one or more of these specific details and using other materials, etc.

[0016] Unless the context requires otherwise, in the specification and claims, the terms "include" and "comprising" should be understood as having an open and inclusive meaning, that is, "including, but not limited to".

[0017] The terms "embodiment," "one embodiment," "another embodiment," or "certain embodiments" mentioned in the specification mean that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment. Therefore, "embodiment," "one embodiment," "another embodiment," or "certain embodiments" do not necessarily all refer to the same embodiment. Moreover, specific features, structures, or characteristics may be combined in any manner in one or more embodiments. Each feature disclosed in the specification may be replaced by any alternative feature that can provide the same, equal, or similar purpose. Therefore, unless otherwise specified, the disclosed features are merely general examples of equal or similar features.

[0018] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods in the following examples, for which no specific conditions are specified, are generally based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, all percentages, ratios, proportions, or parts are by weight.

[0019] “Mass space velocity” is the ratio of feed mass to catalyst mass per unit time.

[0020] "Loading amount" refers to the mass fraction of the active component element to the mass fraction of the carrier.

[0021] The difficulty in the selective oxidation activation of propane lies in the fact that propane is a saturated alkane with no functional groups, no lone pairs or π orbital electrons, and a very small C-H bond orbital. In contrast, the target of the selective oxidation reaction of propane is generally an intermediate product, which is more reactive and more easily oxidized than propane. Due to the complexity of the reaction process, in order to obtain valuable intermediates, a multifunctional catalyst is needed that can break the C-H bond of propane to form propylene, and at the same time can selectively further insert oxygen into propylene to form valuable oxygenated compounds, such as acetone, and it is necessary to prevent the formation of undesirable oxygenated compounds and deep oxidation products such as CO. x This means that the catalyst needs to achieve a good balance of oxidation-reduction with propane and the oxidant during the catalytic process, thus posing a great challenge to the surface properties of the catalyst. The catalyst provided in this application can well meet these functions.

[0022] A propane oxidation activation catalyst comprises an active component, an M2 metal and a carrier. The active components are Mo and V elements, and the M2 metal is selected from one or a mixture of two or more of the elements Li, Na, K, Cs, Mg, Ca, Sr and Ba.

[0023] The carrier is selected from one or a combination of more than one of Al2O3, SiO2, kaolin, clay, talc, diatomaceous earth, aluminum silicate, magnesium silicate, MgO, CaO and La2O3.

[0024] The carrier is preferably one or a combination of more than one of Al2O3, SiO2 and kaolin.

[0025] The content of Mo element in the catalyst is approximately between 40wt% and 60wt%.

[0026] The content of V element in the catalyst is approximately between 12wt% and 20wt%.

[0027] In certain embodiments, the content of M2 in the catalyst is between 0.1 and 5 wt%.

[0028] Preferably, M2 is selected from one of the elements Li, Na, K, and Cs, or a mixture of two or more.

[0029] The catalyst in which the active components Mo and V and M2 (one or a mixture of two or more elements selected from Li, Na, K, and Cs) are loaded onto a carrier of Al2O3, SiO2, or kaolin is used in a reaction system for the oxidation and activation of propane to produce propylene and acetone. The deep oxidation product CO x The content is low.

[0030] In some embodiments, M2 is selected from one of Na, K, and Cs elements, or a mixture of two or more thereof.

[0031] Preferably, M2 is selected from one or a mixture of two or more Cs elements.

[0032] In the catalyst of this application, M2 selects alkali metal elements loaded into Al2O3, SiO2, and kaolin, and is applied to the reaction system of preparing propylene and acetone from propane to improve the selectivity of propylene. In particular, metal Cs is selected, which has a low electronegativity and a strong alkalinity of the corresponding oxide, which can effectively reduce the acid sites on the catalyst surface, thereby improving the selectivity of the intermediate product propylene, and the CO in the product is x The content is low.

[0033] In certain embodiments, the content of the carrier in the catalyst is between 10 and 30 wt%.

[0034] The preparation method of the catalyst comprises: mixing a soluble salt of the Mo element and a soluble salt containing the V element with a carrier aqueous solution to obtain a suspension; evaporating the suspension to dryness to form a solid; and drying and calcining the obtained solid to obtain a catalyst.

[0035] The catalyst synthesis method of the present application adopts an evaporation-drying method. Compared with the hydrothermal method, the synthesis process is simple, and energy consumption and cost are low. On the other hand, the crystalline phase of the product synthesized by the hydrothermal method is different from that of the evaporation-drying method. The crystalline phase of the catalyst synthesized by the hydrothermal method is conducive to producing more acrylic acid, acetone, acetic acid, acrolein and other oxygenated products in the propane selective oxidation reaction, while the catalyst synthesized by the evaporation-drying method is conducive to producing a more single oxygenated product, namely acetone and acetic acid, and the acetic acid selectivity is lower, which improves the selectivity of the target products propylene and acetone. As a result, the sum of the selectivities of acetone and propylene produced is higher.

[0036] In certain embodiments, the soluble salt of the Mo element and the soluble salt containing the V element are mixed with the carrier aqueous solution at a temperature of 40 to 90° C. to obtain a suspension.

[0037] Preferably, the soluble salt of the Mo element and the soluble salt containing the V element are mixed with the carrier aqueous solution at a temperature of 60 to 80° C. to obtain a suspension.

[0038] Soluble salts of the Mo element include, but are not limited to, ammonium molybdate; and soluble salts of the V element include, but are not limited to, ammonium metavanadate.

[0039] In certain embodiments, the drying temperature is in the range of 50-110°C; preferably in the range of 60-90°C.

[0040] There is no limit to the drying time, as long as the degree of drying and moisture content reach a certain range.

[0041] Typically, the drying time is 2 hours to 24 hours, preferably, the drying time is 8 hours to 15 hours.

[0042] In certain embodiments, the calcination process is performed in an inert atmosphere at a temperature between 200° C. and 700° C.

[0043] Preferably, the calcination temperature is 400-600°C.

[0044] Calcination time is 1.5 to 3 hours.

[0045] The inert gas can be nitrogen, argon, CO2, etc., preferably nitrogen.

[0046] In certain embodiments, a soluble salt of the Mo element, a soluble salt containing the V element, a soluble salt or hydroxide of M2 is mixed with a carrier aqueous solution at a temperature of 40 to 90° C. to obtain a suspension.

[0047] The amount of the soluble salt of the Mo element, the soluble salt containing the V element, or the soluble salt or hydroxide of M2 can satisfy the ratio between the substances in the above catalyst.

[0048] On the other hand, a method for preparing propylene and acetone by oxidative activation of propane is provided, wherein propane undergoes an oxidative activation reaction with an oxidant in the temperature range of 200 to 400° C. under the action of the above-mentioned catalyst to produce propylene and acetone.

[0049] In certain embodiments, the reaction temperature is in the range of 240-340°C.

[0050] Preferably, the reaction temperature is controlled at 280-320°C. At this temperature, under the action of the above catalyst, the conversion rate of propane, the selectivity of propylene and acetone are kept very good, and CO x The content is low.

[0051] The oxidant can be oxygen, air, hydrogen peroxide or organic peroxide, etc. Oxygen is preferred.

[0052] In certain embodiments, water vapor is introduced into the reaction system.

[0053] The molar ratio of propane to water vapor is 1:(0.1-20).

[0054] Preferably, the molar ratio of propane to water vapor is 1:(1-5).

[0055] Water vapor has a significant effect on the selective oxidation of propane on the composite metal oxide catalyst of the present application. Adding appropriate water vapor to the feed gas will increase the selectivity for oxygen-containing products. Water can simultaneously change the reaction pathway and the surface properties of the catalyst. Specifically, water may compete with propane, propylene or other intermediates for adsorption sites. As the concentration of surface hydroxyl groups increases, the acid-base properties of the catalyst surface will also change. In the presence of appropriate water vapor, the generation rate of oxygen-containing products increases, that is, the selectivity of acetone is improved. The presence of water vapor makes the deep oxidation product CO x The selectivity of propylene decreases, while the selectivity of propylene decreases only slightly, so the sum of the selectivities of propylene and acetone remains very high.

[0056] When the amount of water vapor used exceeds 1:20 (the molar ratio of propane to water vapor), the conversion rate of propane is low, which affects the yield of the final product.

[0057] In the reaction raw materials, the molar ratio of propane to oxygen is 1:(0.1-1).

[0058] Preferably, the molar ratio of propane to oxygen is 1:(0.2-0.4).

[0059] The space velocity is 0.5 to 4.5 L / (g·h), preferably 1 to 3 L / (g·h).

[0060] The unit of space velocity is g, which represents the mass of the catalyst. The volume L is the sum of the feed gas volumes, which includes water vapor, oxygen, and propane. When calculating the volume, water vapor is calculated as an ideal gas. The unit represents the volume of gas (L) passing through per gram of catalyst per hour.

[0061] The reaction is carried out under normal pressure.

[0062] In this reaction, the reaction temperature is relatively low, below 400 ° C, the selectivity of acetone and propylene can reach more than 91%, and the single-pass conversion rate of propane is above 25%. x The content is low.

[0063] Compared with the prior art, the advantages of this application are as follows:

[0064] The catalyst of the present application can directly convert propane into propylene and acetone through catalytic oxidation, and the sum of the selectivities of the two can reach over 90%, which is difficult to achieve for the current direct oxidation of propane to produce propylene or other oxygen-containing compounds.

[0065] Short process. The current acetone production method involves alkylation of propylene to produce cumene, oxidation of cumene to produce cumene hydroperoxide, and catalytic decomposition of cumene hydroperoxide into phenol and acetone. This method has a long process flow. The method proposed in this invention converts propane into acetone in one step, significantly shortening the process flow.

[0066] Low energy consumption, CO x Low emissions. The existing propane oxidation activation process has low selectivity for propylene and generates a large amount of CO x , and has no application value. The method proposed by the present invention has high selectivity in yield of the target product and is feasible. The current propane to propylene route follows the catalytic dehydrogenation route, which is a strong endothermic reaction, has high energy consumption, and the catalyst is easily deactivated. The present invention follows the catalytic oxidation route, which is an exothermic reaction, has low energy consumption, and the catalyst is not easily deactivated. Compared with the existing propane oxidative dehydrogenation technology, the alkane oxidation activation method of the present invention has high selectivity for the target product and is closer to an atom-economic reaction.

[0067] The following is a detailed description of the reaction and calculation process of using the catalyst in the embodiment of the present invention to produce propylene through oxidation and activation of propane and co-produce acetone:

[0068] The catalyst was evaluated using a fixed-bed quartz tube reactor. The catalyst was installed in the middle of the quartz tube and supported by quartz sand on the top and bottom. Propane, oxidant, and water vapor entered from the top of the reactor. Propylene, acetone, and acetic acid were generated under the action of the catalyst. The bottom of the reactor was connected to a liquid condensation device and a gas collection bag.

[0069] In the selective activation of propane to produce propylene and acetone, the reaction products are divided into gas and liquid phases. The gaseous products include CO, CO2, and propylene, while the liquid products are mainly acetone, acetic acid, etc.

[0070] The conversion rate, selectivity and yield were calculated according to the following formula:

[0071] Conversion rate (%) = the amount of propane consumed in the reaction / the amount of propane at the reactor inlet × 100%

[0072] Selectivity (%) = amount of product produced / amount of propane consumed in the reaction × 100% × n / m

[0073] Yield (%) = amount of product material generated / amount of propane material at the reactor inlet × 100% × n / m

[0074] Where n is the number of carbon atoms in the product and m is the number of carbon atoms in propane.

[0075] The substances used in the following examples are all chemically pure and standard, and are all commercially available conventional products.

[0076] Example 1

[0077] Preparation of Mo1V 0.5 Li 0.05 O x / Al2O3 catalyst. Weigh 7.5g of ammonium molybdate tetrahydrate and dissolve it in deionized water at 80℃. Add 2.5g of ammonium metavanadate during stirring. After complete dissolution, add 0.09g of lithium hydroxide monohydrate, the metal source of the M2 component, and continue stirring. Then add 8.9g of aluminum sol (aluminum sol is calculated as Al2O3 with a mass fraction of 20%) until evaporated to dryness. A light yellow solid is obtained. Place the solid in an oven at 80℃ and dry it for 12h. After taking it out, grind it to obtain a light yellow powder. Calcinate the powder in a tubular furnace under N2 atmosphere for 2h at a temperature of 600℃ and a heating rate of 3℃ / min. Finally, a black powder is obtained, which is ground, tableted and sieved to obtain a catalyst.

[0078] In the obtained catalyst, the mass content of Mo element is 50.3 wt%, the mass content of V element is 13.5 wt%, and the mass content of Li element is 0.2 wt%.

[0079] 3g of the above catalyst was weighed and added to a fixed-bed quartz tube reactor for propane selective activation. The reaction conditions were: temperature 300°C, space velocity (GHSV) = 2245 mL / (g·h), standard atmospheric pressure, and a molar ratio of propane, oxygen, and water vapor in the feed gas of 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes of reaction for analysis.

[0080] Example 2

[0081] Preparation of Mo1V 0.5 Na 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that in Example 1, except that the metal source of the M2 component is changed to crystalline sodium acetate, and the added amount is 0.29 g.

[0082] In the obtained catalyst, the mass content of Mo element is 49.6 wt%, the mass content of V element is 13.2 wt%, and the mass content of Na element is 0.6 wt%.

[0083] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0084] Example 3

[0085] Preparation of Mo1V 0.5 K 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that in Example 1, except that the metal source of the M2 component is changed to potassium nitrate, and the amount of potassium nitrate added is 0.21 g.

[0086] In the obtained catalyst, the mass content of Mo element is 49.4 wt%, the mass content of V element is 13.2 wt%, and the mass content of K element is 1 wt%.

[0087] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0088] Example 4

[0089] Preparation of Mo1V 0.5 Cs 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that in Example 1, except that the metal source of the M2 component is changed to cesium hydroxide monohydrate, and the added amount is 0.36g.

[0090] In the obtained catalyst, the mass content of Mo element is 47.6 wt%, the mass content of V element is 12.7 wt%, and the mass content of Cs element is 3.3 wt%.

[0091] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0092] Example 5

[0093] Preparation of Mo1V 0.5 Mg 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that described in Example 1, except that the metal source of the M2 component is changed to magnesium nitrate hexahydrate, and the amount of magnesium nitrate hexahydrate added is 0.54 g.

[0094] In the obtained catalyst, the mass content of Mo element is 50.6 wt%, the mass content of V element is 13.5 wt%, and the mass content of Mg element is 0.6 wt%.

[0095] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0096] Example 6

[0097] Preparation of Mo1V 0.5 Ca 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that described in Example 1, except that the metal source of the M2 component is changed to calcium nitrate tetrahydrate, and the amount of calcium nitrate tetrahydrate added is 0.50 g.

[0098] In the obtained catalyst, the mass content of Mo element is 49.9 wt%, the mass content of V element is 13.3 wt%, and the mass content of Ca element is 1 wt%.

[0099] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0100] Example 7

[0101] Preparation of Mo1V 0.5 Sr 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that in Example 1, except that the metal source of the M2 component is changed to strontium chloride hexahydrate, and the added amount is 0.57g.

[0102] In the obtained catalyst, the mass content of Mo element is 49.2 wt%, the mass content of V element is 13.1 wt%, and the mass content of Sr element is 2.3 wt%.

[0103] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0104] Example 8

[0105] Preparation of Mo1V 0.5 Ba 0.05 O x / Al2O3 catalyst. The catalyst preparation process in this example is the same as that in Example 1, except that the metal source of the M2 component is changed to barium chloride dihydrate, and the added amount is 0.52g.

[0106] In the obtained catalyst, the mass content of Mo element is 51.1 wt%, the mass content of V element is 13.7 wt%, and the mass content of Ba element is 3.7 wt%.

[0107] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0108] Example 9

[0109] Preparation of Mo1V 0.5 Cs 0.05 O x / SiO2 catalyst. The catalyst preparation process in this example is the same as that described in Example 4, except that the carrier sol is changed to silica sol (the mass fraction of silica sol is 30% based on SiO2) and the added amount is 5.94 g.

[0110] In the obtained catalyst, the mass content of Mo element is 47.1 wt%, the mass content of V element is 12.6 wt%, and the mass content of Cs element is 3.3 wt%.

[0111] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0112] Example 10

[0113] Preparation of Mo1V 0.5 Cs 0.05 O x / CaO catalyst. The catalyst preparation process in this example is the same as that described in Example 4, except that the carrier is changed to calcium oxide, and the added amount is 1.78 g.

[0114] In the obtained catalyst, the mass content of Mo element is 48 wt%, the mass content of V element is 12.8 wt%, and the mass content of Cs element is 3.4 wt%.

[0115] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0116] Example 11

[0117] Preparation of Mo1V 0.5 Cs 0.05 O x / La2O3 catalyst. The catalyst preparation process in this example is the same as that described in Example 4, except that the carrier is changed to lanthanum oxide, and the added amount is 1.78g.

[0118] In the obtained catalyst, the mass content of Mo element is 50.5 wt%, the mass content of V element is 13.5 wt%, and the mass content of Cs element is 3.5 wt%.

[0119] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0120] Example 12

[0121] Preparation of Mo1V 0.5 Cs 0.05 O x / Kaolin catalyst. The catalyst preparation process in this example is the same as that in Example 4, except that the carrier is changed to kaolin, and the added amount is 1.78 g.

[0122] In the obtained catalyst, the mass content of Mo element is 50 wt%, the mass content of V element is 13.4 wt%, and the mass content of Cs element is 3.5 wt%.

[0123] 4 g of the above catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0124] The following are examples of different water vapor contents in the reaction feed gas.

[0125] Example 13

[0126] This example uses the Mo1V prepared in Example 4 0.5 Cs 0.05 O x / Al2O3 catalyst, used in the reaction system of producing propylene and acetone from propane.

[0127] The above catalysts were weighed and added to a fixed-bed quartz tube reactor for propane selective activation. The reaction temperature was 300°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and standard atmospheric pressure was used. The molar ratio of propane to oxygen in the feed gas was 4 / 1, and no water vapor was introduced. Gas and liquid samples were collected and analyzed after 120 minutes.

[0128] Example 14

[0129] This example uses the Mo1V prepared in Example 4 0.5 Cs 0.05 O x / Al2O3 catalyst, used in the reaction system of producing propylene and acetone from propane.

[0130] The catalyst was weighed and added to a fixed-bed quartz tube reactor for propane selective activation. The reaction temperature was 300°C, the gas space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 12. Gas and liquid samples were collected after 120 minutes for analysis.

[0131] The following examples are examples of different reaction temperatures.

[0132] Example 15

[0133] This example uses the Mo1V prepared in Example 4 0.5 Cs 0.05 O x / Al2O3 catalyst, used in the reaction system of producing propylene and acetone from propane.

[0134] The catalyst was weighed and added to a reactor for propane selective activation. The reaction temperature was 280°C, the hourly space velocity (GHSV) was 2245 mL / (g·h), and the molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were collected after 120 minutes for analysis.

[0135] Example 16

[0136] This example uses the Mo1V prepared in Example 4 0.5 Cs 0.05 O x / Al2O3 catalyst, used in the reaction system of producing propylene and acetone from propane.

[0137] The catalyst was weighed and added to the reactor. The reaction temperature was 320°C, the space velocity (GHSV) was 2245 mL / (g·h), and the molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were taken for analysis after 120 minutes.

[0138] Example 17

[0139] This example uses the Mo1V prepared in Example 4 0.5 Cs 0.05 O x / Al2O3 catalyst, used in the reaction system of producing propylene and acetone from propane.

[0140] The catalyst was weighed and added to the reactor. The reaction temperature was 340°C, the space velocity (GHSV) was 2245 mL / (g·h), and the molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. Gas and liquid samples were taken for analysis after 120 minutes.

[0141] Comparative Example 1

[0142] In a fixed-bed reactor, only quartz sand was filled, the reaction temperature was 300°C, the molar ratio of the raw gas was propane / oxygen / water vapor = 4 / 1 / 6, the reaction was carried out under standard atmospheric pressure, and gas and liquid samples were taken for analysis after 120 minutes of reaction.

[0143] Comparative Example 2

[0144] Preparation of Mo1V 0.5 O x To prepare a 1.5-μm / Al2O3 catalyst, 7.5 g of ammonium paramolybdate and 2.5 g of ammonium metavanadate were dissolved in 80°C hot water. 8.9 g of alumina sol was then added to the mixture to form a suspension. The suspension was stirred and evaporated to dryness. The mixture was then dried in an 80°C oven overnight and ground to obtain a pale yellow powder. The powder was then calcined in a tube furnace under a nitrogen atmosphere at 600°C for 2 h at a heating rate of 3°C / min. The resulting black powder was ground, tableted, and sieved to obtain the catalyst.

[0145] The above catalyst was loaded into the reactor and the reaction was carried out at a reaction temperature of 300° C. and standard atmospheric pressure. The molar ratio of propane, oxygen and water vapor in the raw gas was 4 / 1 / 6. Samples were taken for analysis after 120 minutes.

[0146] Comparative Example 3

[0147] The catalyst preparation process in this comparative example is the same as that described in Example 4, except that the content of the carrier in the catalyst is adjusted to 50wt%, the molar ratio of the raw gas is propane / oxygen / water vapor = 4 / 1 / 6, and gas and liquid samples are taken for analysis after reacting at 300°C for 120 minutes.

[0148] Comparative Example 4

[0149] The catalyst preparation process in this comparative example is the same as that described in Example 4, except that no carrier component is added to synthesize Mo1V 0.5 Cs 0.05 O x catalyst.

[0150] The above catalyst was added to the reactor, the reaction temperature was 300°C, and under standard atmospheric pressure, the molar ratio of propane, oxygen, and water vapor in the raw gas was 4 / 1 / 6. After reacting at 300°C for 120 minutes, gas and liquid samples were taken for analysis.

[0151] Comparative Example 5

[0152] The catalyst preparation process in this comparative example is the same as that described in Example 3, except that no carrier component is added to synthesize Mo1V 0.5 K 0.05 O x catalyst.

[0153] The results of the Examples and Comparative Examples using an alkali metal M2-modified catalyst for the oxidation and activation of propane to produce propylene and acetone demonstrate that the catalyst effectively improves the selectivity of propylene and acetone as intermediate products of propane oxidation and activation. Furthermore, by controlling the water vapor content in the feed gas, the product composition can be specifically regulated. The reaction results for the Examples and Comparative Examples are shown in Table 1.

[0154] Table 1. Reaction results

[0155]

[0156]

[0157] Experimental Example 1

[0158] This experimental example is a stability test of the catalyst prepared in Example 4.

[0159] 4 g of the catalyst prepared in Example 4 was weighed and added to a reactor for propane oxidation activation reaction. The reaction temperature was 300°C, the space velocity (GHSV) was 2245 mL / (g·h), and the pressure was standard atmospheric pressure. The molar ratio of propane, oxygen, and water vapor in the feed gas was 4 / 1 / 6. The feed gas was continuously introduced over the catalyst for 48 hours. Gas and liquid samples were taken every 2 hours for analysis. The results are shown in the attached figure. Figure 1 shown.

[0160] From the attached Figure 1 From the results shown in FIG. 1 , the selectivity of propylene and acetone (AC) remains stable, and the selectivity of the sum of the two is about 90% or higher.

[0161] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims rather than the foregoing description, and all variations that come within the meaning and range of equivalents of the claims are intended to be included in this application.

Claims

1. A propane oxidation activation catalyst comprising an active component, an M2 metal and a carrier, wherein the active components are Mo and V elements. M2 metal is selected from one or a mixture of two or more of Li, Na, K, Cs, Mg, Ca, Sr, and Ba elements; Preferably, M2 is selected from one or a mixture of two or more elements selected from Li, Na, K, and Cs; More preferably, M2 is selected from Cs elements.

2. The catalyst according to claim 1, characterized in that The content of Mo element in the catalyst is 40wt%-60wt%; The content of V element in the catalyst is between 12wt% and 20wt%; Preferably, the content of M2 in the catalyst is between 0.1 and 5 wt%.

3. The catalyst according to claim 1 or 2, characterized in that The carrier is selected from one or a combination of more than one of Al2O3, SiO2, kaolin, clay, talc, diatomaceous earth, aluminum silicate, magnesium silicate, MgO, CaO and La2O3; Preferably, the carrier is one or a combination of more than one of Al2O3, SiO2, and kaolin; More preferably, the content of the carrier in the catalyst is between 10 and 30 wt%.

4. A method for preparing the catalyst according to claim 1, comprising: A soluble salt of the Mo element, a soluble salt containing the V element, a soluble salt of M2 or a hydroxide and a carrier are mixed and stirred in an aqueous solution to obtain a suspension; the suspension is stirred until it is evaporated to dryness to form a solid; the obtained solid is dried and calcined to obtain a catalyst.

5. The preparation method according to claim 4, wherein the soluble salt of the Mo element and the soluble salt containing the V element are mixed with the carrier aqueous solution at a temperature of 40 to 90° C. to obtain a suspension; Preferably, the soluble salt of the Mo element and the soluble salt containing the V element are mixed with the carrier aqueous solution at a temperature of 60 to 80° C. to obtain a suspension.

6. The preparation method according to claim 4 or 5, characterized in that The drying temperature is in the range of 50-110°C, preferably in the range of 60-90°C; Preferably, the calcination process is carried out in an inert atmosphere at a temperature of 200 to 700°C; More preferably, the calcination temperature is 400-600°C.

7. A method for producing propylene and acetone by oxidative activation of propane, comprising: reacting propane with an oxidant in the presence of a catalyst according to any one of claims 1 to 3 at a temperature of 200 to 400° C. to produce propylene and acetone; Preferably, the reaction temperature is within the range of 240 to 340°C; More preferably, the space velocity is 0.5 to 4.5 L / (g·h); The preferred range is 1 to 3 L / (g·h).

8. The method according to claim 7, characterized in that The oxidant is oxygen, air, hydrogen peroxide or an organic peroxide; preferably oxygen; More preferably, water vapor is introduced into the reaction system.

9. The method according to claim 7 or 8, characterized in that The molar ratio of propane to water vapor is 1:(0.1-20); Preferably, the molar ratio of propane to water vapor is 1:(1-5).

10. The method according to claim 8 or 9, characterized in that In the reaction raw materials, the molar ratio of propane to oxygen is 1:(0.1-1); Preferably, the molar ratio of propane to oxygen is 1:(0.2-0.4).

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