CN111375415B

CN111375415B - Catalyst for preparing olefin by low-carbon alkane dehydrogenation and preparation method thereof

Info

Publication number: CN111375415B
Application number: CN201811643427.8A
Authority: CN
Inventors: 孙晓丹; 宋永一; 张舒冬; 张庆军; 刘继华; 方向晨
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2022-10-11
Anticipated expiration: 2038-12-29
Also published as: CN111375415A

Abstract

The invention discloses a catalyst for preparing olefin by dehydrogenating low-carbon alkane and a preparation method thereof, wherein the catalyst comprises an active component, an auxiliary agent and a carrier, the active component is one or more of Fe, co, ni, V, mo, cr, mn, cu or Zn, the auxiliary agent is one or more of IA group, IIA group, rare earth elements, al, ti, zr, nb and Ga, and the carrier is silicon-based modified petroleum coke-based active carbon. The preparation method comprises the steps of (1) pretreating petroleum coke, (2) preparing silicon-based modified petroleum coke, and (3) preparing a composite oxide containing an active component and an auxiliary agent; (4) Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and the activating agent and then activating; and (4) washing and drying the sample obtained in the step (4) to obtain the catalyst. The prepared catalyst has the advantages of good dispersion of active components, high utilization rate, high selectivity of low-carbon olefin and the like.

Description

Catalyst for preparing olefin by low-carbon alkane dehydrogenation and preparation method thereof

Technical Field

The invention belongs to the field of chemical catalysis, relates to a catalytic material and a preparation method thereof, and particularly relates to a catalyst for preparing olefin by dehydrogenation of low-carbon alkane and a preparation method thereof.

Background

The low-carbon olefin generally refers to an olefin having a carbon number of 4 or less, and is a very important organic chemical raw material. Ethylene is a very important intermediate in petrochemical industry and is a basic raw material of modern petrochemical industry. Propylene is an important chemical raw material, can be used for synthesizing materials such as polypropylene, polyacrylonitrile, acrolein, acrylic acid, propylene oxide and the like, and can also be used for producing products such as plastics, polypropylene, organic glass, epoxy resin and the like. Isobutene is currently used mainly for the synthesis of the gasoline additive methyl tert-butyl ether (MTBE) and in addition to this for the production of fine chemicals such as isoprene and methyl methacrylate, tert-butyl alcohol and elastomers such as butyl rubber, isoprene rubber and polyisobutylene rubber.

The production of light olefins mainly adopts light hydrocarbon (naphtha, light diesel oil and the like) cracking, and due to the gradual shortage of global petroleum resources and the long-term high-level operation of crude oil price, a new route for replacing the traditional olefin production method is urgently required to be developed. The dehydrogenation preparation of the low-carbon olefin by utilizing the low-carbon alkane which is rich in source and low in price is one of the most promising methods. Dehydrogenation of light alkanes is a strong endothermic reaction, and the ideal olefin yield can be obtained only at a relatively high reaction temperature. However, too high a reaction temperature tends to bring about a series of side reactions, which decrease the selectivity of the olefin and increase the deactivation of the catalyst. While oxidative dehydrogenation of oxygen can solve the above problems, deep oxidation of the alkane inevitably occurs during the reaction, so that the reaction does not yield a high selectivity at the desired conversion.

Carbon dioxide is a weaker oxidant than oxygen. Carbon dioxide is added into a reaction system for preparing olefin by dehydrogenating low-carbon alkane, (1) the equilibrium conversion rate can be improved; (2) Partial energy is provided for dehydrogenation endothermic reaction, and the reaction temperature is reduced; (3) As a mild oxidant, deep oxidation of ethane does not occur, and the selectivity of the product ethylene is ensured; (4) removing carbon deposit to improve the stability of the catalyst; (5) Elimination of some greenhouse gas CO ₂ And meets the current environmental protection requirement. Therefore, the method for preparing the olefin by dehydrogenating the low-carbon alkane in the carbon dioxide atmosphere is a green new process with great application prospect.

CN1339336A discloses a catalyst for preparing ethylene by dehydrogenation of carbon dioxide oxidized ethane at low temperature. The catalyst is prepared by an impregnation method, is composed of porous activated carbon loaded metal oxide, and has an ethylene yield of 14% at a temperature of 973K.

CN106563489A discloses a catalyst which takes small-grain all-silicon silicalite-1 with MFI structure as a carrier and chromium oxide as an active component. In the preparation process, soluble chromium salt is used as a precursor, silicalite-1 zeolite is introduced by an impregnation method, and the supported catalyst is prepared by roasting. The catalyst of the present invention is used in ethane dehydrogenation reaction in carbon dioxide atmosphere, and has high ethylene selectivity and yield. However, the active component chromium of the catalyst is a toxic metal, which is not environment-friendly.

CN101785993B discloses a catalyst for propane dehydrogenation to propylene in carbon dioxide atmosphere. The catalyst is prepared by adopting an impregnation method in the prior art by taking HZSM-5 molecular sieve with high silica-alumina ratio as a carrier and zinc oxide as an active component. The catalyst shows higher steady-state activity and has obvious promotion effect on carbon dioxide.

CN102485331A, CN102728364A, CN102631914A, CN104437568A, CN 104437456A, CN106311201A respectively constructs Fe, co, ni, ru, P, V, cu, sn, pt and Ga catalysts loaded by mesoporous carbon by utilizing the characteristics of high specific surface area, large aperture and favorable diffusion, and the catalysts have better performance of selectively oxidizing isobutane by carbon dioxide to generate isobutene.

Disclosure of Invention

The applicant finds that the existing catalysts for preparing olefin by oxidizing low-carbon alkane with carbon dioxide are all prepared by adopting an impregnation method, and in the process of preparing the catalysts by adopting the impregnation method, the dispersibility of active metal on the surface of a carrier is poor due to the fact that active metal particles are easy to agglomerate, the oxidation capacity is limited when the catalysts are used in the alkane oxidative dehydrogenation process, the catalysts are easy to coke and lose activity due to carbon deposition, and the catalysts are difficult to popularize and apply on industrial devices.

Aiming at the problems in the prior art, the invention provides a catalyst for preparing low-carbon olefin by carbon dioxide oxidation and low-carbon alkane dehydrogenation and a preparation method thereof.

The invention provides a catalyst for preparing low-carbon olefin by carbon dioxide oxidation and dehydrogenation of low-carbon alkane, which comprises an active component, an auxiliary agent and a carrier, wherein the active component is one or more of Fe, co, ni, V, mo, cr, mn, cu or Zn, the auxiliary agent is one or more of IA group, IIA group, rare earth elements, al, ti, zr, nb and Ga, preferably one or more of Mg, K, zr and Ce, and the carrier is silicon-based modified petroleum coke-based activated carbon, wherein based on the weight of the catalyst, the content of an active component oxide is 1-20%, preferably 3-15%, the content of the auxiliary agent oxide is 1-10%, preferably 3-8%, and the content of the carrier is 70-98%, preferably 77-94%.

The catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide has the following properties: the specific surface area is 500-1800 m ² A/g of 700 to 1600m is preferred ² /g。

In the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the active components and the auxiliary agent are embedded into the amorphous defects of the petroleum coke-based active carbon and the active carbon graphite microchip layer, and the size of the active metal crystal grain is 1.5-5.8 nm, preferably 2.5-5 nm.

The second aspect of the invention provides a preparation method of a catalyst for preparing low-carbon olefin by carbon dioxide oxidation and low-carbon alkane dehydrogenation, which comprises the following steps:

(1) Pretreating petroleum coke;

(2) Preparing silicon-based modified petroleum coke;

(3) Preparing a composite oxide containing an active component and an auxiliary agent;

(4) Mixing the silicon-based modified petroleum coke obtained in the step (2), the composite oxide obtained in the step (3) and an activating agent, and activating after uniformly mixing;

(5) And (5) washing and drying the sample obtained in the step (4) to obtain the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the pretreatment in the step (1) comprises the following steps:

(1.1) introducing ammonium phosphate salt into petroleum coke, and then drying;

(1.2) pretreating the sample obtained in the step (1.1) with water vapor-containing gas.

In the method, the ammonium phosphate salt in the step (1.1) is one or more of ammonium phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate, and is preferably ammonium phosphate.

In the above method, the method for introducing the ammonium phosphate salt into the petroleum coke in the step (1.1) is performed according to a method known in the art, and comprises one or more of an equal volume impregnation method, a supersaturated impregnation method and a kneading method, and is preferably a supersaturated impregnation method.

In the method, the drying temperature in the step (1.1) is 60-120 ℃, preferably the drying temperature is 80-100 ℃, the drying time is 2-8 h, and preferably the drying time is 4-6 h. The drying is further preferably carried out under vacuum conditions.

In the method, the weight ratio of the ammonium phosphate salt to the petroleum coke in the step (1.1) is 0.1-1: 1, preferably 0.3 to 0.8:1.

in the above method, the vapor-containing gas in step (1.2) is vapor or a mixed gas of vapor and a carrier gas, and the volume ratio of vapor to carrier gas in the mixed gas is 1; the carrier gas is nitrogen or inert gas, and the inert gas is one or more of helium, neon, argon, krypton and xenon.

In the method, the pretreatment in the step (1.2) comprises a first-stage pretreatment, a second-stage pretreatment and a cooling process, wherein the temperature of the first-stage pretreatment is 150-250 ℃, the preferred temperature is 180-220 ℃, and the pretreatment time is 1-6 hours, the preferred time is 2-4 hours; the second-stage pretreatment temperature is 300-500 ℃, preferably 350-450 ℃, the pretreatment time is 1-6 hours, preferably 2-4 hours, and the second-stage pretreatment is cooled to 20-100 ℃, preferably 40-80 ℃; the cooling process is preferably carried out under nitrogen protection.

In the method, the volume space velocity of the vapor-containing gas in the step (1.2) is 500 to 2000h ^-1 。

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the preparation method of the silicon-based modified petroleum coke in the step (2) comprises the following steps:

(2.1) uniformly mixing a surfactant, a solvent and deionized water to obtain a solution A;

and (2.2) uniformly mixing the petroleum coke pretreated in the step (1), the silicon-containing compound and the solution A, and then filtering, washing and drying to obtain the silicon-based modified petroleum coke.

In the above method, the surfactant in step (2.1) may be one or more of cetyltrimethylammonium bromide (CTAB), organic dicarboxylic acid, and fatty amine, preferably one or more of cetyltrimethylammonium bromide (CTAB), glutaric acid, and dodecylamine; the solvent can be one or more of hydrochloric acid, absolute ethyl alcohol and citric acid, wherein the concentration of the hydrochloric acid is 0.5-2.5M/L; the mass ratio of the surfactant to the solvent to the deionized water is 1:1 to 10:5 to 60. The mixing of step (2.1) may be carried out at room temperature.

In the above method, the silicon-containing compound in step (2.2) may be silica sol, water glass or tetraethoxysilane, preferably tetraethoxysilane; the mass ratio of the petroleum coke (calculated by the mass of the initially added petroleum coke) to the silicon-containing compound (calculated by the mass of the silicon element) after the pretreatment in the step (1) is 1:0.01 to 0.05 of a silicon-containing compound (SiO) _x Mass) and the surfactant in the step (2.1) are in a mass ratio of 1-1.5

In the above method, the mixing in step (2.2) is performed at 20-90 ℃, and the mixing can be performed by any operation in the art that can achieve uniform mixing of two-phase materials, such as mechanical stirring, electrical stirring, and the like, and the mixing time is 2-6 hours.

In the method, the drying temperature in the step (2.2) is 100-150 ℃, and the drying time is 2-12 h.

In the method, the washing in the step (2.2) is carried out by using a proper amount of deionized water until the pH value of the filtrate is neutral.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the composite oxide containing the active component and the auxiliary agent in the step (3) is prepared by the following method:

(3.1) weighing a proper amount of active component soluble salt, assistant-containing metal soluble salt and deionized water to prepare a metal precursor salt solution A;

(3.2) under the stirring condition, uniformly adding the metal precursor salt solution A obtained in the step (3.1) into an organic acid solution, adjusting the pH value to 1-4, then heating at 50-90 ℃, preferably 60-80 ℃ until the solution becomes sticky colloid, and then drying and roasting to obtain the composite oxide.

In the above method, the active component soluble salt in step (3.1) may be one or more of nitrate, sulfate, hydrochloride, manganate, molybdate and vanadate, preferably nitrate, manganate, molybdate or vanadate, specifically may be one or more of iron nitrate, cobalt nitrate, nickel nitrate, ammonium metavanadate, ammonium molybdate, chromium nitrate, potassium permanganate, sodium permanganate, potassium molybdate, sodium molybdate, ammonium molybdate, molybdic acid, copper nitrate and zinc nitrate, and more preferably is one or more of iron nitrate, cobalt nitrate, nickel nitrate, ammonium metavanadate, ammonium molybdate, chromium nitrate, potassium permanganate, potassium molybdate, copper nitrate and zinc nitrate.

In the above method, the soluble salt containing an auxiliary metal in step (3.1) may be one or more of nitrate, sulfate, hydrochloride and oxalate, preferably nitrate, and specifically may be one or more of magnesium nitrate, cerium nitrate, potassium nitrate and zirconium nitrate.

In the above method, the organic acid in step (3.1) is an organic acid containing a carboxyl group, and the organic acid containing a carboxyl group is a hydroxycarboxylic acid composed of C, H, O, specifically, one or more of maleic acid, citric acid, and fumaric acid, and more preferably, citric acid.

In the method, the mass ratio of the organic acid to the active component soluble salt (calculated by the mass of the active component oxide) to the auxiliary agent element-containing soluble salt (calculated by the mass of the auxiliary agent oxide) is 5-15: 1:0.03 to 15, preferably 5 to 10:1:0.15 to 3.4.

In the method, nitric acid or ammonia water is used for adjusting the pH in the step (3.2), and the concentration of the nitric acid or the ammonia water is 0.05-0.5 mol/L; the drying temperature is 80-150 ℃, the drying time is 2-10 h, the preferred drying temperature is 100-120 ℃, and the drying time is 4-6 h; the roasting temperature is 300-800 ℃, the roasting time is 2-8 h, the preferred roasting temperature is 400-600 ℃, and the roasting time is 4-6 h.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the activating agent in the step (4) is one or more of potassium hydroxide, sodium hydroxide, potassium bicarbonate and sodium bicarbonate, and the potassium hydroxide is preferred.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the mass ratio of the composite oxide (calculated by the mass of the active component oxide), the activating agent and the silicon-based modified petroleum coke (calculated by the mass of the initially added petroleum coke) in the step (4) is 0.005-0.16: 0.5 to 4:1, preferably 0.015 to 0.11:1 to 3:1.

in the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the activation process in the step (4) is as follows: uniformly mixing the composite oxide, an activating agent and the silicon-based modified petroleum coke, heating to an activation temperature in a nitrogen or inert atmosphere, cooling to 20-100 ℃ after activation, and performing subsequent treatment, wherein the inert atmosphere is one or more of helium or argon; the activation temperature is 400-900 ℃, preferably 600-800 ℃, and the activation time is 5-120 min, preferably 10-90 min. The activation process is further preferably carried out under the condition of microwave radiation, and the microwave frequency is 2450MHz or 915MHz; the microwave power is 1-10 kw, preferably 2-4 kw per kg of petroleum coke. When the activation is carried out under the microwave radiation condition, the activation is further preferably carried out in two sections, the first section is activated for 10 to 60min under the vacuum condition and at the temperature of between 400 and 600 ℃, inert gas or nitrogen is introduced to the atmosphere under the constant temperature condition, and the temperature is continuously increased to between 700 and 900 ℃ under the microwave radiation condition for activation for 10 to 30min.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the washing in the step (5) is water washing, firstly, the sample obtained in the step (4) is mixed with deionized water, and after uniform mixing, solid-liquid separation is carried out until the pH value of the filtrate is neutral. The mass ratio of the sample obtained in the step (4) to the deionized water is 1:5-1, preferably 1.

In the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the drying temperature in the step (5) is 100-200 ℃, the preferred drying temperature is 120-180 ℃, the drying time is 2-10 h, and the preferred drying time is 4-8 h. The drying is preferably carried out under vacuum.

The third aspect of the invention provides a catalyst for preparing low-carbon olefin by the dehydrogenation of carbon dioxide oxidized low-carbon alkane, which is prepared by the method.

In the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide, the catalyst comprises an active component, an auxiliary agent and a carrier, wherein the active component is one or more of Fe, co, ni, V, mo, cr, mn, cu and Zn, the auxiliary agent is one or more of IA group, IIA group, rare earth elements, al, ti, zr, nb and Ga, preferably one or more of Mg, K, zr and Ce, and the carrier is silicon-based modified petroleum coke-based activated carbon, wherein the content of an oxide of the active component is 1-20%, preferably 3-15%, the content of an oxide of the auxiliary agent is 1-10%, preferably 3-8%, and the content of the carrier is 70-98%, preferably 77-94% on the basis of the weight of the catalyst.

In the catalyst for preparing low carbon olefin by carbon dioxide oxidation and low carbon alkane dehydrogenation, the catalyst for preparing low carbon olefin by carbon dioxide oxidation and low carbon alkane dehydrogenation has the following properties: the specific surface area is 500-1800 m ² A/g of 700 to 1600m is preferred ² /g。

In the catalyst for preparing low-carbon olefin by carbon dioxide oxidation and low-carbon alkane dehydrogenation, the active component and the auxiliary agent are embedded into the amorphous defect of the petroleum coke-based active carbon and the active carbon graphite microchip layer, and the size of the active metal crystal grain is 1.5-5.8 nm, preferably 2.5-5 nm.

The fourth aspect of the invention provides an application of the catalyst in preparation of low-carbon olefin by carbon dioxide oxidation and dehydrogenation of low-carbon alkane.

Compared with the prior art, the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide and the preparation method thereof have the following advantages:

1. in the preparation method of the catalyst, the petroleum coke is pretreated firstly, the ammonium phosphate is introduced into the petroleum coke, and then the petroleum coke is treated by adopting steam-containing gas, so that the ammonium phosphate is promoted to be decomposed in the petroleum coke to generate ammonia gas and phosphoric acid, the generated ammonia gas provides more primary pores for further activation of the petroleum coke, and meanwhile, the generated phosphoric acid can also be used as an activating agent to carry out primary activation on the petroleum coke, so that a developed pore structure is created. Solves the problems of serious equipment corrosion and higher production cost caused by the fact that petroleum coke is compact in structure, high in crystallinity and lack of primary pores required by activation and is activated to form pores by adopting strong alkali with an alkali-coke ratio of more than 3/1 in an inert atmosphere in the prior art.

2. In the preparation method of the catalyst, the phosphoric acid generated by decomposing the ammonium phosphate salt plays a primary activation role on petroleum coke, so that the dosage of a subsequent alkali activator can be reduced, and the catalyst is low in production cost and small in environmental pollution.

3. In the preparation method of the catalyst, siO is introduced into pretreated petroleum coke _x The/surfactant compound is heated by microwave to decompose the surfactant to obtain the active carbon and the worm pore SiO _x The composite carrier improves the connectivity of carrier pore passages, is beneficial to the diffusion of reactants, intermediate products and products in pores, reduces the deep oxidation of the intermediate products and further improves the selectivity of the products.

4. According to the catalyst and the preparation method thereof, active metal and an auxiliary agent are introduced in the petroleum coke activation process, the active metal and the auxiliary agent enter a diffusion path generated by petroleum coke phase through an activating agent, and are combined with amorphous carbon defects or graphite carbon sheet layers under the action of microwave catalysis to form a high-dispersion and stable-state structure, so that the problem of uneven distribution of the active metal caused by weak action of the inert surface of a carbon-based carrier and the metal of a low-carbon alkane dehydrogenation catalyst taking active carbon as the carrier is solved, and the prepared catalyst has the advantages of good dispersion of active components, high utilization rate, high selectivity of low-carbon alkene and the like.

5. The preparation method of the catalyst improves the dispersion degree of active metal on the surface of the carrier, reduces carbon deposition in the reaction process, improves the diffusion rate of alkane oxidative dehydrogenation intermediate products and low-carbon olefin products, reduces deep oxidation of the intermediate products and the products, and further improves the selectivity of the olefin products.

Detailed Description

The technical solutions of the present invention are further illustrated below with reference to examples, but are not limited to the following examples.

The specific surface and pore size distribution of the catalyst in the following examples and comparative examples are shown by using low temperature N ₂ Measured by the adsorption method.

Example 1

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (the volume space velocity of water vapor gas is 500 h) ^-1 ) And then raising the temperature to 400 ℃, continuing to pretreat for 3h, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

And uniformly mixing 8g of hexadecyl trimethyl ammonium bromide, 40g of citric acid and 200g of deionized water to obtain a solution B, weighing 22.25g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, and drying the obtained colloid at 120 ℃ for 4 hours to obtain the silicon-based modified petroleum coke.

Weighing 31.45g of ferric nitrate and 1.36g of cerous nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 2 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, then putting the viscous colloid into an oven, drying for 5 hours at 110 ℃, and roasting the obtained sample at 700 ℃ for 5 hours to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 500 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 40min, introducing nitrogen to the normal pressure, and continuously heating to 800 ℃ under the condition that the microwave power is 0.3kw to activate for 20min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the Fe content of 10 percent of the catalyst by mass in terms of oxide ₂ O ₃ 、5%CeO ₂ 、4.8%SiO ₂ The catalyst for the dehydrogenation of ethane to ethylene is denoted as C-1.

Example 2

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke is ground into powder, then added into the solution A, placed for 1.5h and then filtered, and the solid sample obtained is dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (volume space velocity of water vapor gas is 800 h) ^-1 ) And raising the temperature to 400 ℃, continuing to pretreat for 3 hours, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Uniformly mixing 8g of glutaric acid, 40g of hydrochloric acid (the concentration is 1.5 moL/L) and 230g of deionized water to obtain a solution B, weighing 22.25g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, and drying the obtained colloid at 120 ℃ for 4 hours to obtain the silicon-based modified petroleum coke.

Weighing 11.3g of potassium permanganate and 2.07g of potassium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 1 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, then putting the viscous colloid into an oven, drying for 5 hours at 110 ℃, and roasting the obtained sample at 700 ℃ for 5 hours to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of sodium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 600 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 20min, introducing nitrogen to the normal pressure, and continuously heating to 900 ℃ under the condition that the microwave power is 0.3kw for activation for 10min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the MnO content of 10 percent of the catalyst by mass in terms of oxide ₂ 、5%K ₂ O、4.8%SiO ₂ The catalyst for the dehydrogenation of ethane to ethylene is denoted as C-2.

Example 3

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (the volume space velocity of water vapor gas is 1200 h) ^-1 ) And then raising the temperature to 400 ℃, continuing to pretreat for 3h, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Uniformly mixing 8g of dodecylamine, 40g of anhydrous ethanol and 230g of deionized water to obtain a solution B, weighing 22.25g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, carrying out solid-liquid separation, washing the obtained solid with deionized water until the filtrate is neutral, and drying for 4 hours at 120 ℃ to obtain the silicon-based modified petroleum coke.

Weighing 24.19g of nickel nitrate and 2.88g of zirconium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 3 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide, 200g of potassium bicarbonate and 100g of potassium hydroxide, putting the mixture into a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 400 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 60min, introducing nitrogen to the normal pressure, and continuously heating to 700 ℃ under the condition that the microwave power is 0.3kw for activation for 30min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the catalyst with the mass percentage of oxide accounting for 10 percent of NiO and 5 percent of ZrO ₂ 、4.8%SiO ₂ The catalyst for producing propylene by dehydrogenation of propane is denoted as C-3.

Example 4

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample for 3h at 200 ℃ by using mixed gas with the volume ratio of water vapor to argon of 1:5 (the volume space velocity of the mixed gas is 1200 h) ^-1 ) And then raising the temperature to 400 ℃, continuing to pretreat for 3h, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Weighing 9.24g of ammonium metavanadate and 19.77g of magnesium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 2 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide, 100g of sodium bicarbonate and 200g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 500 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 40min, introducing nitrogen to the normal pressure, and continuously heating to 800 ℃ under the condition that the microwave power is 0.3kw to activate for 20min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, drying at 150 ℃ for 6 hours under the vacuum condition, and obtaining the catalyst with the mass percent of 10 percent V calculated by oxide ₂ O ₅ 、5%MgO、4.8%SiO ₂ The catalyst for the dehydrogenation of propane to propylene is designated as C-4.

Example 5

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (the volume space velocity of water vapor gas is 1200 h) ^-1 ) Then the temperature is raised to 400 ℃, the pretreatment is continued for 3 hours, and then the mixture is cooled to 60 ℃ under the protection of nitrogen, thus obtaining the pretreated petroleumAnd (3) charring.

Weighing 24.19g of nickel nitrate and 1.36g of cerium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 3 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, then putting the viscous colloid into an oven, drying for 5 hours at 110 ℃, and roasting the obtained sample at 700 ℃ for 5 hours to obtain the composite oxide.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the catalyst with the mass percentage of oxide accounting for 10 percent of NiO and 5 percent of CeO ₂ 、4.8%SiO ₂ The catalyst for preparing isobutene by isobutane dehydrogenation is marked as C-5.

Example 6

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (the volume space velocity of water vapor gas is 1200 h) ^-1 ) Then the temperature is increased to 400 ℃, the pretreatment is continued for 3 hours, and then the mixture is put in nitrogenCooling to 60 ℃ under protection to obtain the pretreated petroleum coke.

Weighing 17.53g of cupric nitrate and 2.07g of potassium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to be 4 by adopting a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, then drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 600 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 20min, introducing nitrogen to the normal pressure, and continuously heating to 900 ℃ under the condition that the microwave power is 0.3kw to activate for 10min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the catalyst which accounts for 10 percent of CuO, 5%K by mass in terms of oxide ₂ O、4.8%SiO ₂ The catalyst for preparing isobutene by dehydrogenating isobutane is marked as C-6.

Example 7

Weighing 50g of ammonium dihydrogen phosphate, and dissolving in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (of water vapor gas)The volume space velocity is 1200h ^-1 ) And then raising the temperature to 400 ℃, continuing to pretreat for 3h, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Uniformly mixing 3g of hexadecyl trimethyl ammonium bromide, 13g of citric acid and 80g of deionized water to obtain a solution B, weighing 7.42g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, and drying the obtained colloid at 120 ℃ for 4 hours to obtain the silicon-based modified petroleum coke.

Weighing 12.97g of ferric nitrate and 0.67g of cerous nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 20g of citric acid, and dissolving in 100mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 1 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 400 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 60min, introducing nitrogen to the normal pressure, and continuously heating to 700 ℃ under the condition that the microwave power is 0.3kw to activate for 30min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the Fe content of 5 percent of the catalyst by mass in terms of oxide ₂ O ₃ 、3%CeO ₂ 、2%SiO ₂ The catalyst for the dehydrogenation of ethane to ethylene of (1) is denoted as C-7.

Example 8

Weighing 50g of ammonium hydrogen phosphate, and dissolving in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 90 ℃ for 8h. At 200 deg.C, using steamPretreating the dried solid sample for 3h with mixed gas with the volume ratio of nitrogen being 1:2 (the volume space velocity of the mixed gas is 800 h) ^-1 ) And then raising the temperature to 400 ℃, continuing to pretreat for 3 hours, and then cooling to 40 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Uniformly mixing 11g of dodecylamine, 55g of anhydrous ethanol and 300g of deionized water to obtain a solution B, weighing 30g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, carrying out solid-liquid separation, washing the obtained solid with the deionized water until the filtrate is neutral, and drying for 4 hours at 120 ℃ to obtain the silicon-based modified petroleum coke.

Weighing 43.64g of nickel nitrate and 5.55g of zirconium nitrate, and dissolving in 100mL of deionized water to obtain a solution C; weighing 90g of citric acid, and dissolving in 150mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 2 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

And uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of potassium hydroxide, placing the mixture into a tube furnace, and heating to 800 ℃ to activate for 40min in a nitrogen atmosphere. .

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the catalyst with the mass percentage of oxide accounting for 15 percent of NiO and 8 percent of ZrO ₂ 、5.35%SiO ₂ The catalyst for producing propylene by propane dehydrogenation is marked as C-8.

Example 9

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. At 200 ℃, a mixture of water vapor and helium gas with a volume ratio of 1Pretreating the dried solid sample for 3h with the mixed gas (the volume space velocity of the mixed gas is 1500 h) ^-1 ) And raising the temperature to 400 ℃, continuing to pretreat for 3 hours, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Uniformly mixing 13g of glutaric acid, 65g of hydrochloric acid (the concentration is 1.5 moL/L) and 400g of deionized water to obtain a solution B, weighing 37.1g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution B, stirring for 4 hours, and drying the obtained colloid at 120 ℃ for 4 hours to obtain the silicon-based modified petroleum coke.

Weighing 71.49g of nickel nitrate and 4.02g of cerium nitrate, and dissolving in 150mL of deionized water to obtain a solution C; weighing 150g of citric acid, and dissolving in 200mL of deionized water to obtain a solution D; and dropwise adding the solution C into the solution D under the stirring condition, adjusting the pH value of the obtained mixed solution to 3 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Uniformly mixing the silicon-based modified petroleum coke, the composite oxide and 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, and heating to 900 ℃ in nitrogen atmosphere under the condition that the microwave power is 0.3kw for activation for 20min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the catalyst with the mass percent of 20 percent NiO and 10 percent CeO calculated by oxide ₂ 、5.44%SiO ₂ The catalyst for preparing isobutene by isobutane dehydrogenation is marked as C-9.

Comparative example 1

Weighing 31.45g of ferric nitrate and 1.36g of cerous nitrate, and dissolving in 100mL of deionized water to obtain a solution A; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution B; under the condition of stirring, dropwise adding the solution A into the solution B, adjusting the pH value of the obtained mixed solution to 2 by using a 0.2mol/L nitric acid solution, then heating at 80 ℃ until the solution becomes a sticky colloid, then drying for 5 hours in an oven at 110 ℃, and roasting the obtained sample for 5 hours at 700 ℃ to obtain the composite oxide.

Grinding 100g of petroleum coke into powder, uniformly mixing the powder with the composite oxide and 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 500 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 40min, introducing nitrogen to the normal pressure, and continuously heating to 800 ℃ under the condition that the microwave power is 0.3kw to activate for 20min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the Fe content of 10 percent of the catalyst by mass in terms of oxide ₂ O ₃ 、5%CeO ₂ The catalyst for the dehydrogenation of ethane to ethylene is denoted as D-1.

Comparative example 2

Weighing 50g of ammonium phosphate, and dissolving the ammonium phosphate in 200mL of deionized water to obtain a solution A; 100g of petroleum coke was ground to a powder, then added to solution A, left to stand for 1.5h, then filtered, and the resulting solid sample was dried in an oven at 110 ℃ for 5h. Pretreating the dried solid sample with water vapor at 200 deg.C for 3h (the volume space velocity of water vapor gas is 1200 h) ^-1 ) And raising the temperature to 400 ℃, continuing to pretreat for 3 hours, and then cooling to 60 ℃ under the protection of nitrogen to obtain the pretreated petroleum coke.

Grinding the silicon-based modified petroleum coke into powder, then uniformly mixing the powder with 300g of potassium hydroxide, placing the mixture in a microwave heating furnace with microwave frequency of 2450MHz, vacuumizing, heating to 500 ℃ under the condition that the microwave power is 0.3kw, keeping the temperature constant for 40min, then introducing nitrogen to the normal pressure, and continuing heating to 800 ℃ under the condition that the microwave power is 0.3kw to activate for 20min.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying for 6 hours at 150 ℃ under the vacuum condition.

Weighing 31.45g of ferric nitrate and 1.36g of cerium nitrate, dissolving in 100mL of deionized water, adding into the sample obtained in the step of vacuum drying, stirring uniformly, aging for 2h, then placing in a vacuum drying oven, drying at 150 ℃ for 6h under a vacuum condition, roasting the dried sample at 700 ℃ for 6h under a nitrogen atmosphere, and obtaining Fe accounting for 10 percent of the catalyst by mass in terms of oxide ₂ O ₃ 、5%CeO ₂ 、4.8%SiO ₂ The catalyst for the dehydrogenation of ethane to ethylene is denoted as D-2.

Comparative example 3

Uniformly mixing 8g of hexadecyl trimethyl ammonium bromide, 40g of citric acid and 200g of deionized water to obtain a solution A, weighing 22.25g of tetraethyl orthosilicate, uniformly mixing the tetraethyl orthosilicate with the pretreated petroleum coke and the solution A, stirring for 4 hours, and drying the obtained colloid at 120 ℃ for 4 hours to obtain the silicon-based modified petroleum coke.

31.45g ferric nitrate and 1.36g cerous nitrate are weighed and dissolved in 100mL deionized water to obtain a solution B; weighing 50g of citric acid, and dissolving in 100mL of deionized water to obtain a solution C; and (2) dropwise adding the solution B into the solution C under the stirring condition, adjusting the pH value of the obtained mixed solution to 2 by using a 0.2mol/L nitric acid solution, heating at 80 ℃ until the solution becomes a viscous colloid, then putting the viscous colloid into an oven, drying for 5 hours at 110 ℃, and roasting the obtained sample at 700 ℃ for 5 hours to obtain the composite oxide.

Grinding the activated sample into powder, weighing, and mixing the powder according to a mass ratio of 1:15 and deionized water, fully stirring, then carrying out solid-liquid separation until the pH value of the filtrate is neutral, placing the obtained solid sample in a vacuum drying oven, and drying at 150 ℃ for 6 hours under the vacuum condition to obtain the Fe content of 10 percent of the catalyst by mass in terms of oxides ₂ O ₃ 、5%CeO ₂ 、4.8%SiO ₂ The catalyst for the dehydrogenation of ethane to ethylene is denoted as D-3.

Evaluation conditions were as follows: the reaction for preparing olefin by dehydrogenating light alkane is carried out on a miniature reaction device of a normal pressure fixed bed. The reaction temperature is 500-700 ℃, and the dosage of the catalyst is 200mg. Alkane in the raw material gas: CO 2 ₂ ：N ₂ =1：1：4，GHSV=3000mL﹒g ^-1 ﹒h ^-1 The reaction results are shown in Table 1.

TABLE 1 catalyst Properties and reaction Performance

Claims

1. A catalyst for preparing low-carbon olefin by carbon dioxide oxidation and dehydrogenation of low-carbon alkane comprises an active component, an auxiliary agent and a carrier, wherein the active component is one or more of Fe, co, ni, V, mo, cr, mn, cu or Zn, the auxiliary agent is one or more of IA group, IIA group, rare earth elements, al, ti, zr, nb and Ga, and the carrier is silicon-based modified petroleum coke-based activated carbon, wherein the content of the active component is 1-20%, the content of the auxiliary agent element is 1-10% and the content of the carrier is 70-98% based on the weight of the catalyst;

the preparation method of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide comprises the following steps:

(1) Pretreating petroleum coke; the pretreatment comprises the following steps:

(1.1) introducing ammonium phosphate salt into petroleum coke, and then drying;

(1.2) pretreating the sample obtained in the step (1.1) with water vapor-containing gas;

(2) Preparing silicon-based modified petroleum coke;

2. The catalyst for preparing low-carbon olefin by the dehydrogenation of low-carbon alkane oxidized by carbon dioxide according to claim 1, which is characterized in that: the auxiliary agent is selected from one or more of Mg, K, zr and Ce, and based on the weight of the catalyst, the content of the active component is 3-15%, the content of the auxiliary agent element is 3-8%, and the content of the carrier is 77-94%.

3. The catalyst for preparing low-carbon olefin by the dehydrogenation of low-carbon alkane oxidized by carbon dioxide according to claim 1, which is characterized in that: the specific surface area of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide is 500 to 1800m ² /g。

4. The catalyst for preparing low-carbon olefin by the dehydrogenation of low-carbon alkane oxidized by carbon dioxide according to claim 1 or 3, which is characterized in that: the specific surface area of the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide is 700 to 1600m ² /g。

5. The catalyst for preparing low-carbon olefin by the dehydrogenation of low-carbon alkane oxidized by carbon dioxide according to claim 1, which is characterized in that: in the catalyst for preparing low-carbon olefin by carbon dioxide oxidation and dehydrogenation of low-carbon alkane, active components and auxiliaries are embedded into amorphous defects of petroleum coke-based activated carbon and an activated carbon graphite microchip layer, and the size of active metal crystal grains is 1.5-5.8 nm.

6. The catalyst for preparing low-carbon olefin by the dehydrogenation of low-carbon alkane oxidized by carbon dioxide according to claim 1 or 5, which is characterized in that: in the catalyst for preparing low-carbon olefin by carbon dioxide oxidation and dehydrogenation of low-carbon alkane, active components and auxiliaries are embedded into amorphous defects of petroleum coke-based activated carbon and an activated carbon graphite microchip layer, and the size of active metal crystal grains is 2.5-5 nm.

7. The method for preparing the catalyst for preparing the low carbon olefin by the dehydrogenation of the carbon dioxide oxidized low carbon alkane in any one of the claims 1 to 6, wherein the preparation method comprises the following steps:

(1) Pretreating petroleum coke; the pretreatment comprises the following steps:

(1.1) introducing ammonium phosphate salt into petroleum coke, and then drying;

(2) Preparing silicon-based modified petroleum coke;

(5) And (4) washing and drying the sample obtained in the step (4) to obtain the catalyst for preparing the low-carbon olefin by oxidizing the low-carbon alkane with carbon dioxide and dehydrogenating the low-carbon alkane.

8. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: in the step (1.1), the ammonium phosphate salt is one or more of ammonium phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate.

9. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7 or 8, which is characterized by comprising the following steps of: in the step (1.1), the ammonium phosphate salt is ammonium phosphate.

10. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: in the step (1.1), the drying temperature is 60-120 ℃, and the drying time is 2-8 h.

11. The method for preparing a catalyst for preparing a low-carbon olefin by the dehydrogenation of a low-carbon alkane oxidized by carbon dioxide according to claim 7 or 10, which comprises the following steps: in the step (1.1), the drying temperature is 80-100 ℃, and the drying time is 4-6 h.

12. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to the claim 7 or 10, which is characterized in that: the drying in step (1.1) is carried out under vacuum.

13. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7, which comprises the following steps: in the step (1.1), the weight ratio of the ammonium phosphate to the petroleum coke is 0.1-1: 1.

14. the method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7 or 13, which is characterized by comprising the following steps of: in the step (1.1), the weight ratio of the ammonium phosphate to the petroleum coke is 0.3-0.8: 1.

15. the method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: in the step (1.2), the vapor-containing gas is vapor or a mixed gas of the vapor and a carrier gas, and the volume ratio of the vapor to the carrier gas in the mixed gas is 1; the carrier gas is nitrogen or inert gas, and the inert gas is one or more of helium, neon, argon, krypton and xenon.

16. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7 or 15, which is characterized by comprising the following steps: in the step (1.2), the gas containing water vapor is water vapor or a mixed gas of water vapor and a carrier gas, and the volume ratio of the water vapor to the carrier gas in the mixed gas is 1-1:2; the carrier gas is nitrogen or inert gas, and the inert gas is one or more of helium, neon, argon, krypton and xenon.

17. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7, which comprises the following steps: the pretreatment in the step (1.2) comprises a first-stage pretreatment, a second-stage pretreatment and a cooling process, wherein the temperature of the first-stage pretreatment is 150-250 ℃, and the pretreatment time is 1-6 h; the second stage of pretreatment is carried out at the temperature of 300-500 ℃ for 1-6 h, and the second stage of pretreatment is cooled to 20-100 ℃.

18. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: the pretreatment in the step (1.2) comprises a first-stage pretreatment, a second-stage pretreatment and a cooling process, wherein the temperature of the first-stage pretreatment is 180-220 ℃, and the pretreatment time is 2-4 h; the second stage of pretreatment is carried out at 350-450 ℃ for 2-4 h, and the second stage of pretreatment is cooled to 40-80 ℃.

19. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 17 or 18, which is characterized by comprising the following steps: the cooling process is carried out under the protection of nitrogen.

20. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: the volume space velocity of the vapor-containing gas in the step (1.2) is 500 to 2000h ^-1 。

21. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7, which comprises the following steps: the preparation method of the silicon-based modified petroleum coke in the step (2) comprises the following steps:

and (2.2) uniformly mixing the petroleum coke pretreated in the step (1), a silicon-containing compound and the solution A, and then filtering, washing and drying to obtain the silicon-based modified petroleum coke.

22. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide as claimed in claim 21, wherein the method comprises the following steps: the surfactant in the step (2.1) is one or more of cetyl trimethyl ammonium bromide, organic dicarboxylic acid and fatty amine; the solvent is one or more of hydrochloric acid, anhydrous ethanol and citric acid.

23. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 21 or 22, which is characterized in that: the surfactant in the step (2.1) is one or more of cetyl trimethyl ammonium bromide, glutaric acid and laurylamine.

24. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 21, which comprises the following steps: the mass ratio of the surfactant to the solvent to the deionized water is 1:1 to 10:5 to 60.

25. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide as claimed in claim 21, wherein the method comprises the following steps: in the step (2.2), the silicon-containing compound is silica sol, water glass or ethyl orthosilicate; the mass ratio of the petroleum coke pretreated in the step (1) to the silicon-containing compound is 1: 0.01-0.05, and the mass ratio of the silicon-containing compound to the surfactant in the step (2.1) is 1-1.5.

26. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 25, wherein the method comprises the following steps: in the step (2.2), the silicon-containing compound is tetraethoxysilane.

27. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 21, which comprises the following steps: the mixing in step (2.2) is carried out at 2-90 ℃.

28. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 21, which comprises the following steps: in the step (2.2), the drying temperature is 100-150 ℃, and the drying time is 2-12 h.

29. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: the composite oxide containing the active component and the auxiliary agent in the step (3) is prepared by the following method:

(3.1) weighing active component soluble salt, assistant-containing metal soluble salt and deionized water to prepare a metal precursor salt solution A;

(3.2) under the stirring condition, uniformly adding the metal precursor salt solution A into the organic acid solution, adjusting the pH value to be 1-4, then heating at 50-90 ℃ until the solution becomes sticky colloid, and then drying and roasting to obtain the composite oxide.

30. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, wherein the method comprises the following steps: under the condition of stirring, the metal precursor salt solution A is uniformly added into the organic acid solution, the pH value is adjusted to be 1-4, then the solution is heated at the temperature of 60-80 ℃ until the solution becomes sticky colloid, and then the composite oxide is obtained through drying and roasting.

31. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, wherein the method comprises the following steps: and (3.1) the soluble salt of the active component is one or more of nitrate, sulfate, hydrochloride, manganate, molybdate and vanadate.

32. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 31, which is characterized in that: and (3.1) the soluble salt of the active component is nitrate, manganate, molybdate or vanadate.

33. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 31, which is characterized in that: and (3.1) the soluble salt of the active component is one or more of ferric nitrate, cobalt nitrate, nickel nitrate, ammonium metavanadate, ammonium molybdate, chromium nitrate, potassium permanganate, sodium permanganate, potassium molybdate, sodium molybdate, molybdic acid, copper nitrate or zinc nitrate.

34. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 31, which is characterized in that: and (3.1) the soluble salt of the active component is one or more of ferric nitrate, cobalt nitrate, nickel nitrate, ammonium metavanadate, ammonium molybdate, chromium nitrate, potassium permanganate, potassium molybdate, copper nitrate and zinc nitrate.

35. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, wherein the method comprises the following steps: and (4) the soluble salt containing the auxiliary agent metal in the step (3.1) is one or more of nitrate, sulfate, hydrochloride and oxalate.

36. The method for preparing a catalyst for preparing low carbon olefins by dehydrogenation of low carbon alkanes through oxidation of carbon dioxide according to claim 29 or 35, wherein the method comprises the following steps: and (3.1) the soluble salt containing the auxiliary agent metal is nitrate.

37. The method for preparing a catalyst for preparing a low carbon olefin by the dehydrogenation of a low carbon alkane oxidized by carbon dioxide according to claim 29 or 35, wherein the method comprises the following steps: and (3.1) the assistant-containing metal soluble salt is one or more of magnesium nitrate, cerium nitrate, potassium nitrate and zirconium nitrate.

38. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, wherein the method comprises the following steps: the organic acid in the step (3.1) is carboxyl group-containing organic acid, and the carboxyl group-containing organic acid is hydroxycarboxylic acid consisting of C, H, O.

39. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 38, which comprises the following steps: and (4) the organic acid in the step (3.1) is one or more of maleic acid, citric acid and fumaric acid.

40. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 38, which comprises the following steps: and (4) the organic acid in the step (3.1) is citric acid.

41. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, which is characterized in that: the mol ratio of the organic acid, the active component soluble salt and the soluble salt containing the auxiliary agent element is 5-15: 1:0.03 to 15.

42. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 29 or 41, wherein the method comprises the following steps: the mol ratio of the organic acid, the active component soluble salt and the soluble salt containing the auxiliary agent element is 5-10: 1:0.15 to 3.4.

43. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 29, wherein the method comprises the following steps: in the step (3.2), nitric acid or ammonia water is used for adjusting the pH value, and the concentration of the nitric acid or the ammonia water is 0.05-0.5 mol/L; the drying temperature is 80-150 ℃, the drying time is 2-10 h, the roasting temperature is 300-800 ℃, and the roasting time is 2-8 h.

44. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide according to claim 43, wherein the method comprises the following steps: the drying temperature is 100-120 ℃, and the drying time is 4-6 h; the roasting temperature is 400-600 ℃, and the roasting time is 4-6 h.

45. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: and (4) the activating agent is one or more of potassium hydroxide, sodium hydroxide, potassium bicarbonate and sodium bicarbonate.

46. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7 or 45, which is characterized in that: in the step (4), the activating agent is potassium hydroxide.

47. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7, which comprises the following steps: the mass ratio of the composite oxide in the step (4) to the activating agent to the silicon-based modified petroleum coke is 0.005-0.16 in terms of the mass of active metal elements: 0.5 to 4:1.

48. the method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7 or 47, which is characterized in that: the mass ratio of the composite oxide in the step (4) to the activating agent to the silicon-based modified petroleum coke is 0.015-0.11: 1 to 3:1.

49. the method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: the activation process in the step (4) is as follows: uniformly mixing the composite oxide, the activating agent and the silicon-based modified petroleum coke, heating to an activation temperature in an inert atmosphere, cooling to 20-100 ℃ after activation, and performing subsequent treatment, wherein the activation temperature is 400-900 ℃, and the activation time is 5-120 min.

50. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7 or 49, which is characterized in that: the activation process in the step (4) is as follows: uniformly mixing the composite oxide, the activating agent and the silicon-based modified petroleum coke, heating to an activation temperature in an inert atmosphere, cooling to 20-100 ℃ after activation, and performing subsequent treatment, wherein the activation temperature is 600-800 ℃, and the activation time is 10-90 min.

51. The method for preparing a catalyst for preparing low carbon olefin by dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7, which comprises the following steps: the activation process is carried out under the microwave radiation condition, and the microwave frequency is 2450MHz or 915MHz; the microwave power is 1-10 kW per kg of petroleum coke.

52. The method of claim 51, wherein the carbon dioxide is used to oxidize the lower alkane and the lower alkane to dehydrogenate the lower alkene to produce the lower alkene catalyst, the method comprising the steps of: the microwave power is 2-4 kW per kg of petroleum coke.

53. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes through carbon dioxide oxidation according to claim 51 or 52, wherein the method comprises the following steps: when the activation is carried out under the microwave radiation condition, the activation is carried out in two sections, the first section is activated for 10 to 60min under the vacuum condition and at the temperature of between 400 and 600 ℃, inert gas or nitrogen is introduced to the atmosphere under the constant temperature condition, and the activation is carried out for 10 to 30min after the temperature is continuously raised to between 700 and 900 ℃ under the microwave radiation condition.

54. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: washing in the step (5) is water washing, firstly, mixing the sample obtained in the step (4) with deionized water, uniformly mixing, and then carrying out solid-liquid separation until the pH value of the filtrate is neutral; and (3) the mass ratio of the sample obtained in the step (4) to the deionized water is 1:5-1.

55. The method for preparing a catalyst for preparing light olefins by dehydrogenation of light alkanes oxidized by carbon dioxide as claimed in claim 54, wherein the method comprises the following steps: the mass ratio of the sample obtained in the step (4) to the deionized water is 1.

56. The method for preparing the catalyst for preparing the low-carbon olefin by the dehydrogenation of the low-carbon alkane oxidized by the carbon dioxide according to claim 7, which is characterized by comprising the following steps of: in the step (5), the drying temperature is 100-200 ℃, and the drying time is 2-10 h.

57. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7 or 56, which is characterized in that: in the step (5), the drying temperature is 120-180 ℃, and the drying time is 4-8 h.

58. The method for preparing a catalyst for preparing low carbon olefin by the dehydrogenation of low carbon alkane oxidized by carbon dioxide according to claim 7 or 56, which is characterized in that: the drying in step (5) is carried out under vacuum.

59. Use of the catalyst of any one of claims 1-6 in the dehydrogenation of lower alkanes to lower olefins by oxidation with carbon dioxide.