CN103566966A - N-alkene isomerization catalyst and preparation method thereof - Google Patents

Abstract

The invention discloses an n-alkene isomerization catalyst which comprises a carrier and a modified compound, wherein the mass ratio of the modified compound to the carrier is (0.01-0.4):1, the carrier comprises a mixed molecular sieve and a binder, the modified compound is selected from phenol, monosaccharide or disaccharide and polyalcohol or organic acid ammonia, and the mixed molecular sieve comprises a mesoporous molecular sieve and a macroporous molecular sieve. According to the catalyst, catalytic active components are modified by the modified compound, and the isomerization selectivity of the catalyst can be remarkably improved.

Description

Normal olefin isomerization catalyst and preparation method thereof

technical field

The invention is an olefin isomerization catalyst and a preparation method thereof, specifically, a normal olefin skeleton isomerization catalyst and a preparation method thereof.

Background technique

With the increasingly stringent environmental protection requirements, the demand for clean gasoline continues to increase. Isobutene, methylpentene and dimethylbutene obtained by skeletal isomerization of normal C ₄ -C ₆ olefins can be etherified to prepare high-octane gasoline additives to improve gasoline quality.

USP5,382,743 discloses a method of using ZSM-35 molecular sieve to carry out skeletal isomerization reaction of n-pentene under the condition of hydrogen, and finds that the reaction under the condition of hydrogen is conducive to improving the reactivity of the catalyst and reducing the loss of activity rate and prolong catalyst life.

USP5,817,907 discloses a method for skeletal isomerization of linear olefins. The catalyst used contains at least one pretreated molecular sieve. , Theta-1, EU-1, OMEGA, Mordenite, Nu-10, Nu-86, Nu-87, Ferrierite ZSM-35, ZSM-12 and ZSM-23. The pretreatment method is to contact the molecular sieve with hydrocarbon molecules containing C ₄ -C ₂₀ in the presence of an inert gas. The preferred hydrocarbons are C ₄ -C ₁₂ monoolefins, polyolefins or alkanes, etc., more preferably C _{4 -C} 20 C ₁₂ alkanes. The space velocity of the pretreatment is 0.1h ^-1 ~ 45h ^-1 , the temperature is 300°C ~ 550°C, the pressure is 0.1MPa ~ 1.0MPa, and the treatment time is 0.5 ~ 48 hours. Pretreatment causes coke to deposit in the pores of the molecular sieve, and the pore volume of the molecular sieve is significantly reduced, thereby improving the selectivity of isomerized olefins and having good stability. However, before the olefin isomerization reaction, a step of high-temperature pre-coking treatment using hydrocarbons as raw materials under an inert atmosphere is added, which complicates the reaction process.

Contents of the invention

The purpose of the present invention is to provide a normal olefin isomerization catalyst and its preparation method. The catalyst uses a modifying compound to modify the catalytic active components, which can significantly improve the isomerization selectivity of the catalyst.

The normal olefin isomerization catalyst provided by the present invention includes a carrier and a modified compound, the mass ratio of the modified compound to the carrier is 0.01-0.4:1, the carrier includes a mixed molecular sieve and a binder, and the The modifying compound is selected from phenol, monosaccharide or disaccharide, polyalcohol or ammonium organic acid, and the mixed molecular sieve includes medium-pore molecular sieve and large-pore molecular sieve.

The present invention mixes large-pore molecular sieves and medium-pore molecular sieves as the active components of the isomerization catalyst, and uses modified compounds to modify the catalytic active components. The preparation method of the catalyst is simple, without adding additional processing procedures, and is easy to control. The obtained catalyst is used in the skeletal isomerization reaction of normal olefins, the isomerization selectivity is obviously improved, and the yield of isomerization products is increased.

Detailed ways

The present invention mixes an appropriate amount of large-pore molecular sieves into the medium-pore molecular sieve, so that the relatively cheap ZSM-5 can be used instead of ZSM-35, so that the mixed molecular sieve has the isomerization performance equivalent to that of ZSM-35. In addition, by using modified compounds Modification of the mixed molecular sieve, the modified compound is deposited on the surface of the molecular sieve, can effectively improve its physical and chemical properties and improve its isomerization performance. The invention adopts a simple in-situ treatment method to prepare the catalyst, is easy to operate, and the content of the modified compound in the catalyst is easy to control.

The molecular sieves of the present invention include medium-pore molecular sieves and large-pore molecular sieves, and the preferred medium-pore molecular sieves are ZSM-5 and ZSM-22 and/or SAPO-11, that is, the preferred combination of medium-pore molecular sieves should at least contain ZSM-5 The combination of molecular sieve and medium pore molecular sieve can be ZSM-5 and ZSM-22, ZSM-5 and SAPO-11, or ZSM-5, ZSM-22 and SAPO-11, and the macroporous molecular sieve is preferably Beta molecular sieve.

The binder in the carrier of the present invention is selected from alumina, silica, titania, magnesia, alumina-magnesia, silica-alumina, silica-magnesia, silica-zirconia, silica - thorium oxide, silica-beryllia, silica-titania, silica-zirconia, titania-zirconia, silica-alumina-thoria, silica-alumina-titania, silica-oxide One or more of alumina-magnesia, silica-alumina-zirconia clay, preferably alumina.

The carrier of the present invention includes 50-99% by mass of mixed molecular sieve and 1-50% by mass of binder, preferably 60-95% by mass of mixed molecular sieve and 5-40% by mass of binder. The mass ratio of the modified compound to the carrier in the catalyst of the present invention is preferably 0.01-0.3:1. In the mixed molecular sieve, the mass ratio of the medium-pore molecular sieve to the large-pore molecular sieve is 5-60, preferably 5-50.

The modified compound contained in the catalyst of the present invention has many kinds, selected from phenol, monosaccharide or disaccharide, polyalcohol or ammonium organic acid.

The first modified compound in the present invention—phenol is preferably a phenolic compound represented by formula (I) and/or a naphthol compound represented by formula (II).

In formula (I) and formula (II), -OH represents the hydroxyl group on the benzene ring or naphthalene ring, and its number can be 1 to 3; Y is a substituent on the benzene ring or naphthalene ring, and its number can be 1~3. In the present invention, for the sake of simplicity, Y can also be hydrogen. When Y is hydrogen, formula (I) or formula (II) respectively represent phenol or naphthol, and the phenol can be phenol, diphenol or Pyrogallol. When Y is an alkyl group of C ₁ to C ₃ or -NH ₂ , the formula (I) is an alkylphenol or aminophenol, and the formula (II) is an alkylnaphthol or aminonaphthol.

The phenol is preferably one or more of phenol, diphenol, glucinol, naphthol, cresol or aminophenol.

The second modification compound described in the present invention is monosaccharide or disaccharide, and the number of carbon atoms of the monosaccharide is preferably 3 to 6, preferably triose, tetose, pentose or hexose, and the hexose is preferably Aldohexose, such as glucose, mannose, galactose, hexose can also be ketohexose, such as fructose; the disaccharide is sucrose, lactose, maltose or cellobiose, preferably sucrose.

The third modification compound described in the present invention is a polyol, preferably a C ₂ -C ₇ polyol. The polyhydric alcohol of described _C2 ～ _C7 is preferably ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol one or several.

The fourth modified compound of the present invention is ammonium organic acid, preferably ammonium carboxylate or ammonium amino acid. Described ammonium carboxylate is aliphatic ammonium carboxylate or aromatic ammonium carboxylate, and the carbon chain that aliphatic ammonium carboxylate is connected with carboxyl group does not contain aromatic ring, and the carbon chain that aromatic ammonium carboxylate is connected with carboxyl group contains aromatic ring. The number of carbon atoms of the aliphatic ammonium carboxylate is preferably 1-14, and the number of carbon atoms of the aromatic ammonium carboxylate is preferably 6-10. Preferred ammonium carboxylates are ammonium formate, ammonium acetate, triammonium citrate, ammonium oxalate, ammonium tartrate, ammonium malate, ammonium lactate, diammonium edetate, trans 1,2-cyclohexanediaminetetraacetic acid Ammonium, Ammonium Benzoate, Ammonium Salicylate, Ammonium Caffeate. Ammonium amino acid is preferably triammonium aminotriacetate.

The normal olefins suitable for isomerization by the catalyst of the present invention are preferably C ₄ -C ₆ normal olefins.

The preparation method of the catalyst provided by the present invention comprises mixing the medium-pore molecular sieve and the large-pore molecular sieve with a binder to form, drying and roasting to obtain a carrier, and then impregnating it with a solution of a modified compound. Dry under the condition of 0.01～0.1MPa.

The medium pore molecular sieve is preferably ZSM-5 and ZSM-22 and/or SAPO-11, the macroporous molecular sieve is preferably Beta molecular sieve, and the binder is preferably alumina.

The method of mixing molecular sieve and binder in the method of the present invention is extruding, dropping ball, rolling ball or tableting method, preferably extruding. The extruding method is as follows: uniformly mix the mixed molecular sieve with the binder or its precursor, add an appropriate amount of extrusion aid and/or peptizer and knead, and then extrude and form. The extrusion aid is preferably squash powder, and the peptizing agent is preferably an inorganic acid, such as hydrochloric acid or nitric acid. After the wet strip is cut into pellets, the carrier is obtained by drying and roasting. The temperature of the calcination is preferably 400-650° C., and the calcination time is preferably 1-10 hours.

In the method of the present invention, the mixed molecular sieve can also be pretreated with a modified compound first, then mixed with a binder to form, dried and roasted to obtain a carrier, and then the carrier is impregnated with a solution of a modified compound. Finally, the solid is dried under the conditions of 30-200° C. and 0.01-0.1 MPa to obtain a catalyst, and the modified compound in the catalyst does not include the modified compound used for pretreatment.

The pretreatment method of the above-mentioned mixed molecular sieve is as follows: impregnating the mixed molecular sieve with the solution of the modified compound, then drying the impregnated solid, then mixing it with a binder to form, drying and roasting to obtain a carrier.

When preparing the catalyst of the present invention, the carrier prepared after calcination can also be impregnated with the solution of the modified compound for two or more times, and it needs to be dried after each impregnation. The modifying compound used for each impregnation can be the same or different.

The above-mentioned impregnation is to impregnate the carrier with a solution of a modified compound, which can be saturated impregnation, unsaturated impregnation or supersaturated impregnation, preferably saturated impregnation, also known as incipient wetness impregnation, that is, the volume of the impregnation solution is equal to the amount of liquid absorbed by the carrier; the impregnation time Preferably 0.1 to 24 hours, more preferably 0.5 to 8 hours.

When preparing the immersion liquid, the concentration of the modifying compound solution is 0.01-5.0 mol/liter, preferably 0.01-3.0 mol/liter. After impregnation, the solvent is removed by drying. Drying conditions are controlled so that the modifying compound does not decompose and does not volatilize. The suitable drying temperature is 40~150°C, preferably 60~130°C, the drying time is 1~24 hours, preferably 2~8 hours, and the drying pressure is 0.01~0.1MPa.

In the above method, when the modified compound is phenol, the solvent used to prepare the modified compound solution is an organic substance, and the organic substance is preferably a C ₆ -C ₈ alkane or aromatic hydrocarbon, or a C ₂ -C ₄ aliphatic alcohol. When the modified compound is monosaccharide or disaccharide, polyalcohol or ammonium organic acid, the solvent used to prepare the modified compound solution is water.

The catalyst provided by the invention is suitable for the skeletal isomerization reaction of normal olefins, especially suitable for the skeletal isomerization reaction of C ₄ -C ₆ normal olefins to prepare isomeric olefins.

The isomerization reaction of normal olefins using the catalyst of the present invention is carried out in the presence of hydrogen. The reaction temperature is 200-550°C, preferably 250-350°C, the pressure is 0.05-1MPa, preferably 0.1-0.5MPa, the feed volume space velocity is 0.5-6.0 hours ^-1 , preferably 1-4 hours ^-1 , hydrogen/ The hydrocarbon volume ratio is 100-5000, preferably 200-2000.

The present invention is further illustrated by examples below, but the present invention is not limited thereto.

In the examples, the preparation of the catalyst of the present invention and the introduction of the modified compound into the carrier all adopt the saturated impregnation method, that is, the incipient wetness impregnation method. The molecular sieves used in the examples were all provided by Hunan Jianchang Catalyst Factory, and the pseudo-boehmite was provided by German Condea Company, and its alumina content on a dry basis was 74% by mass.

Example 1

Mix 3568 grams of SAPO-11 molecular sieve, 3946 grams of HZSM-5 molecular sieve, 2326 grams of HZSM-22 molecular sieve, 948 grams of Beta molecular sieve and 1637.8 grams of pseudo-boehmite, add 65.5 grams of nitric acid with a concentration of 65% by mass and 10770 grams of water , extruded into trefoil strips with a diameter of 1.1 mm by a twin-screw extruder, pelletized, dried at 120°C for 4 hours, and calcined at 550°C for 2 hours to obtain a carrier S ₁ , in which the molecular sieve content was 90% by mass and the alumina content was 10% by mass.

Take 2000 grams of carrier S ₁ , impregnate 283.1 grams (2.618 mol) of o-cresol in 1952 ml of n-heptane solution at 25°C for 0.5 hour, and dry at 90°C and 0.01MPa for 2 hours to obtain catalyst C ₁ , whose weight is 2280.9 grams, indicating that the catalyst _C1 contains 280.9 grams of o-cresol, and the mass ratio of the contained phenol to the carrier _S1 is 0.14.

Example 2

Mix 3879.0 grams of SAPO-11 molecular sieve, 3790.0 grams of HZSM-5 molecular sieve, 2898.0 grams of HZSM-22 molecular sieve, 221.0 grams of Beta molecular sieve and 1637.8 grams of pseudo-boehmite, add 65.5 grams of nitric acid with a concentration of 65% by mass and 10770 grams of water , extruded into a trilobal strip with a diameter of 1.1 mm by a twin-screw extruder, pelletized, dried at 120°C for 4 hours, and roasted at 550°C for 2 hours to obtain a carrier S ₂ , in which the molecular sieve content was 90% by mass and the alumina content was 10% by mass.

Take 2000 grams of carrier S ₂ , impregnate 1,955 ml of n-heptane solution containing 326.5 grams (2.965 mol) of catechol at 25°C for 0.5 hour, and then dry at 130°C and 0.01MPa for 2 hours to obtain catalyst C ₂ , and its weight is 2323.2 grams, indicating that catalyst _C2 contains 323.2 grams of catechol, and the mass ratio of contained phenol to carrier _S2 is 0.162.

Example 3

Take 2000 grams of carrier _S1 , impregnate 1952 milliliters of toluene solution containing 567.1 grams (3.934 mol) of naphthol at 25 ° C for 0.5 hours, and then dry at 90 ° C and 0.01 MPa for 2 hours to obtain catalyst _C3 , the weight of which is 2562.1 grams, indicating that catalyst _C3 contains 562.1 grams of naphthol, and the mass ratio of contained phenol to carrier _S1 is 0.281.

Example 4

Take 2000 grams of carrier _S1 , impregnate 1952 ml of aqueous solution containing 172.5 grams (0.870 mol) of D-glucose at 25°C for 0.5 hour, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C4 , the weight of which is 2171.8 grams, indicating that _catalyst C contains 171.8 grams of D-glucose, and the mass ratio of sugar to carrier _S is 0.086.

Example 5

Take 2000 grams of carrier _S2 , impregnate 1955 ml of aqueous solution containing 182.6 grams (0.533 mol) of sucrose at 25°C for 0.5 hour, and then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C5 with a weight of 2182.1 grams , indicating that catalyst _C contains 182.1 grams of sucrose, and the mass ratio of sugar to carrier _S is 0.091.

Example 6

Take 2000 grams of carrier _S1 , impregnate 253.1 grams (2.812 mol) of triose (D-glyceraldehyde and dihydroxyacetone mass ratio of 1:1) aqueous solution 1952 ml at 25 ° C for 0.5 hours, and then at 90 ° C, Drying at 0.01 MPa for 2 hours yielded catalyst C ₆ , which weighed 2251.0 g, indicating that catalyst C ₆ contained 251.0 g of triose, and the mass ratio of sugar to support S ₁ was 0.126.

Example 7

Take 2000 grams of carrier _S1 , impregnate 1952 ml of aqueous solution containing 299.5 grams (3.252 mol) of glycerol at 25 ° C for 0.5 hours, and then dry at 90 ° C and 0.01 MPa for 2 hours to obtain catalyst C ₇ with a weight of 2298.9 grams, indicating that catalyst _C7 contains 298.9 grams of glycerin, and the mass ratio of contained alcohol to carrier _S1 is 0.15.

Example 8

Take 2000 grams of carrier _S2 , impregnate 1955 ml of aqueous solution containing 297.6 grams (2.518 mol) of hexanediol at 25°C for 0.5 hour, and then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C8 with a weight of 2296.9 grams, indicating that the catalyst _C contains 296.9 grams of hexanediol, and the mass ratio of the contained alcohol to the carrier _S is 0.148.

Example 9

Take 2000 g of carrier _S1 , impregnate 1952 ml of aqueous solution containing 289.3 g (1.721 mol) of ammonium malate at 25°C for 0.5 hour, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C9 , the weight of which is 2288.5 grams, indicating that catalyst _C9 contains 288.5 grams of ammonium malate, and the mass ratio of ammonium salt to carrier _S1 is 0.144.

Example 10

Take 2000 grams of carrier S ₂ , impregnate 1,955 ml of an aqueous solution containing 290.5 grams (1.872 mol) of ammonium salicylate at 25°C for 0.5 hours, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst C ₁₀ , whose weight is 2289.7 grams, indicating that catalyst C ₁₀ contains 289.7 grams of ammonium salicylate, and the mass ratio of ammonium salt to carrier S ₂ is 0.145.

Example 11

7980 grams of HZSM-5 molecular sieves, 1120 grams of SAPO-11 and 1688 grams of Beta molecular sieves were impregnated with 10798 ml of n-heptane solution of 120.0 grams (1.110 mol) o-cresol at 25 ° C for 0.5 hours, and then at 90 ° C and 0.01 MPa conditions Drying for 2 hours to obtain a pretreated mixed molecular sieve.

Mix the above-mentioned pretreated mixed molecular sieve with 1637.8 grams of pseudoboehmite, add 65.5 grams of nitric acid and 10770 grams of water with a concentration of 65% by mass, and extrude it into a trefoil strip with a diameter of 1.1 mm with a twin-screw extruder. Cut into pellets, dry at 120°C for 4 hours, and bake at 550°C for 2 hours to obtain carrier S3, in which the molecular sieve content is 90% by mass and the alumina content is 10% by mass.

Take 2000 grams of carrier _S3 , impregnate 1939 ml of n-heptane solution containing 123.0 grams (1.137 mol) o-cresol at 25°C for 0.5 hour, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C11 , Its weight is 2121.5 grams, illustrates that catalyst C ₁₁ contains 121.5 grams of o-cresol, and the mass ratio of contained phenol to carrier S ₃ is 0.061.

Example 12

Take 2000 grams of carrier _S3 , impregnate 1939 ml of aqueous solution containing 90.2 grams (0.455 mol) of D-glucose at 25°C for 0.5 hour, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C12 , the weight of which is 2089.7 grams, illustrate that catalyst C ₁₂ contains 89.7 grams of D-glucose, and the mass ratio of contained sugar to carrier S ₃ is 0.045.

Example 13

Take 2000 g of carrier _S3 , impregnate 1939 ml of aqueous solution containing 134.3 g (1.459 mol) of glycerol at 25°C for 0.5 hour, then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C13 with a weight of 2133.8 grams, illustrate that catalyst C ₁₃ contains 133.8 grams of glycerin, and the mass ratio of contained alcohol to carrier S ₃ is 0.067.

Example 14

Take 2000 grams of carrier _S3 , impregnate 1939 ml of aqueous solution containing 131.6 grams (0.541 mol) of triammonium citrate at 25°C for 0.5 hour, and then dry at 90°C and 0.01MPa for 2 hours to obtain catalyst _C14 , whose weight is 2131.1 grams, indicating that catalyst _C14 contains 131.1 grams of triammonium citrate, and the mass ratio of ammonium salt to carrier _S3 is 0.066.

Example 15~31

The following examples evaluate the isomerization reaction performance of the catalysts of the present invention.

Using 1-pentene as the reaction raw material and the carrier not treated with the modified compound as the comparative catalyst, the catalyst of the present invention and the comparative catalyst were respectively evaluated on a small fixed-bed hydrogenation reactor.

The specific operation method is as follows: the catalyst is loaded in the constant temperature zone of the reactor, and hydrogen gas is introduced to adjust the reaction pressure to 0.3 MPa. Raise the temperature of the reactor to 400°C, stabilize it for 2 hours, then adjust the temperature of the reactor to 300°C, after the temperature stabilizes, inject 1-pentene into the reactor, control the reaction temperature to 300°C, and feed volume space velocity 1.7h ^-1 , the reaction pressure was 0.3MPa, and the hydrogen/hydrocarbon volume ratio was 600. After 12 hours of reaction, samples were taken and analyzed online by gas chromatography. The reaction results are shown in Table 1.

Table 1

As can be seen from the data in Table 1, the catalyst obtained after being treated with the modified compound in the present invention has significantly improved isoamylene yield and isoamylene selectivity compared with the unmodified comparative catalyst.

Claims (22)

1. a normal olefine isomerization catalyst, comprise carrier and modified compound, the mass ratio of described modified compound and carrier is 0.01～0.4:1, described carrier comprises mixed molecular sieve and binding agent, described modified compound is selected from phenol, monose or disaccharides, polyalcohol or organic acid ammonium salt, and described mixed molecular sieve comprises mesoporous molecular sieve and large pore molecular sieve.

2. according to catalyst claimed in claim 1, it is characterized in that described mesoporous molecular sieve is selected from ZSM-5 and ZSM-22 and/or SAPO-11, large pore molecular sieve is Beta molecular sieve.

3. according to catalyst claimed in claim 1, it is characterized in that described mesoporous molecular sieve and the mass ratio of large pore molecular sieve are 5 ~ 50.

4. according to catalyst claimed in claim 1, it is characterized in that described carrier comprises the mixed molecular sieve of 50～99 quality % and the binding agent of 1 ~ 50 quality %.

5. according to catalyst claimed in claim 1, it is characterized in that described phenol is the naphthol compound that has the phenolic compound of formula (I) structure expression and/or have formula (II) structure expression, in formula (I) and formula (II), the number of hydroxyl is 1～3, Y is the substituting group on phenyl ring or naphthalene nucleus, its number is 1 ~ 3, and Y is selected from hydrogen, C ₁～C ₃alkyl or-NH ₂,

6. according to catalyst claimed in claim 5, it is characterized in that described phenol is selected from one or more in phenol, benzenediol, benzenetriol, naphthols, cresols and amino phenols.

7. according to catalyst claimed in claim 1, it is characterized in that described monose carbon number is 3～6, described disaccharides is sucrose.

8. according to catalyst claimed in claim 1, it is characterized in that described polyalcohol is C ₂～C ₇polyalcohol.

9. according to catalyst claimed in claim 8, it is characterized in that described C ₂～C ₇polyalcohol be selected from one or more in ethylene glycol, propane diols, butanediol, pentanediol, hexylene glycol, glycerine, trimethylolethane, pentaerythrite, xylitol and sorbierite.

10. according to catalyst claimed in claim 1, it is characterized in that described organic acid ammonium salt is selected from carboxylic acid ammonium or amino acid ammonium.

11. according to catalyst claimed in claim 10, it is characterized in that described carboxylic acid ammonium is for aliphatic carboxylic acid ammonium or aromatic carboxylic acid ammonium.

12. according to the catalyst described in claim 11, it is characterized in that the carbon number of described aliphatic carboxylic acid ammonium is 1 ~ 14, and the carbon number of aromatic carboxylic acid ammonium is 6 ~ 10.

13. according to catalyst claimed in claim 1, it is characterized in that described binding agent is aluminium oxide.

14. according to catalyst claimed in claim 1, it is characterized in that the normal olefine that described normal olefine is C4～C6.

The preparation method of catalyst described in 15. 1 kinds of claims 1, comprise mesoporous molecular sieve and large pore molecular sieve and binding agent mixed-forming, dry, roasting makes carrier, then uses the solution impregnation of modified compound, and after dipping, solid is dry under 30～200 ℃, 0.01～0.1MPa condition.

16. in accordance with the method for claim 15, it is characterized in that described mesoporous molecular sieve is selected from ZSM-5 and ZSM-22 and/or SAPO-11, and large pore molecular sieve is Beta molecular sieve, and binding agent is aluminium oxide.

17. in accordance with the method for claim 15, it is characterized in that first mixed molecular sieve being carried out to pretreatment with modified compound, preprocess method is the solution impregnation with modified compound, solid drying after then flooding, with binding agent mixed-forming, dry, roasting makes carrier again.

18. in accordance with the method for claim 15, it is characterized in that the carrier making after roasting to use the solution impregnation two of modified compound to repeatedly, after each dipping, all needs to be dried.

19. in accordance with the method for claim 15, and the concentration that it is characterized in that modified compound solution is 0.01～3.0 mol/L.

20. in accordance with the method for claim 18, it is characterized in that the modified compound of each dipping use is identical or different.

21. according to the method described in claim 15 or 17, and while it is characterized in that described modified compound is phenol, preparation modified compound solution solvent used is organic matter, and described organic matter is C ₆～C ₈alkane or aromatic hydrocarbons, or C ₂～C ₄fatty alcohol.

22. according to the method described in claim 15 or 17, and while it is characterized in that described modified compound is monose or disaccharides, polyalcohol or organic acid ammonium salt, preparation modified compound solution solvent used is water.