CN112742456B

CN112742456B - Dehydrogenation cracking catalyst, preparation method thereof and method for producing ethylene and propylene by using carbon tetrahydrocarbon

Info

Publication number: CN112742456B
Application number: CN201911047685.4A
Authority: CN
Inventors: 马文明; 朱根权; 杨超
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2023-09-05
Anticipated expiration: 2039-10-30
Also published as: CN112742456A

Abstract

The invention provides a dehydrogenation cracking catalyst, a preparation method thereof and a method for producing ethylene and propylene by catalyzing carbon tetrahydrocarbon with the dehydrogenation cracking catalyst. The dehydrogenation cracking catalyst comprises, by weight, 10-70% of a carrier, 10-60% of a molecular sieve, 1-40% of a metal active component and 10-50% of a binder, wherein the molecular sieve is a molecular sieve with an MFI structure, and the metal active component is one or more metals or metal oxides selected from Fe, ni, cr, mn, zn, pt and V. The dehydrogenation cracking catalyst of the invention is prepared by carrying out metal modification on a molecular sieve with an MFI structure, improves the catalytic dehydrogenation reaction performance on the basis of keeping the catalytic cracking performance, and achieves the effective coupling of the catalytic dehydrogenation reaction and the catalytic cracking reaction of the carbon tetrahydrocarbon in the process of producing ethylene and propylene by catalyzing the carbon tetrahydrocarbon, thereby improving the yield of the ethylene and the propylene.

Description

Dehydrogenation cracking catalyst, preparation method thereof and method for producing ethylene and propylene by using carbon tetrahydrocarbon

Technical Field

The invention relates to the field of catalysis, in particular to a dehydrogenation cracking catalyst, a preparation method thereof and a method for producing ethylene and propylene by using carbon tetrahydrocarbon.

Background

The main sources of the carbon four fraction are the byproduct of the catalytic cracking device, the byproduct of the steam cracking device and the recovered oil field. In recent years, with the development of coal chemical industry, more carbon four is also generated in the process of preparing olefin from methanol. In China, the comprehensive utilization rate of the carbon four fraction is very low, most of the carbon four fraction is used as industrial or civil fuel, and only less than 40% of the carbon four fraction is used for producing gasoline blending components such as alkylate, methyl tert-butyl ether (MTBE) and the like and chemical products such as resin, rubber and fiber.

With the strong popularization of the national ethanol gasoline, the use of MTBE is limited, and moreover, because some chemical refineries do not have matched alkylation devices, more carbon four fractions cannot be efficiently utilized. The ethylene and propylene markets are rapidly developed, the apparent consumption of the ethylene and propylene markets is increased year by year, and the supply and demand relationship is tense. The method for producing ethylene and propylene by using the carbon four fraction as the raw material can solve the problem of low comprehensive utilization rate of the carbon four fraction and can relieve the market contradiction of ethylene and propylene.

At present, a plurality of companies at home and abroad have developed catalytic cracking technology for the carbon tetraolefins, which mainly comprises an OCP technology of UOP & Atofina, a Propylur technology of Lurgi company, an MOI technology of Mobil company, a Superflex technology of KBR company, an OCC technology of China petrochemical Shanghai petrochemical institute and the like. The catalytic cracking technology is mature, the reaction condition is moderate, the yield of ethylene and propylene exceeds more than 50%, and the disadvantage is that the raw materials with higher content of the tetraalkane cannot be treated, and the continuous reaction-regeneration process cannot be realized when a fixed bed reactor is used. While catalytic cracking of the carbon tetraalkylalkanes is still in the laboratory stage.

CN1506342A discloses a method for producing propylene by catalytic cracking of olefins with four or more carbon atoms. The method adopts ZSM molecular sieve loaded with at least one alkaline earth metal of Mg, ca or Ba as a catalyst, and the olefin with four or more than four carbon atoms as a reaction raw material is subjected to cracking reaction under the conditions of the reaction temperature of 400-600 ℃, the reaction pressure of 0-0.15 MPa and the liquid phase airspeed of 10-50 h < -1 >. The method can obviously improve the selectivity and the yield of propylene.

CN106608789a discloses a method for producing propylene by catalytic cracking of carbon tetraolefins. The method takes the residual carbon four as a raw material, forms ZSM-5 molecular sieve raw powder with the shape index of 3-100, then carries out alkali treatment to obtain the molecular sieve catalyst with a composite pore structure, and reacts under the conditions of the reaction temperature of 400-600 ℃, the reaction pressure of 0-0.3 MPa and the weight hourly space velocity of 1-50 h < -1 >. The method can obviously improve the stability of the catalyst and the propylene selectivity.

CN105289622a discloses a catalyst for preparing mono-olefin by dehydrogenating saturated alkane, the catalyst comprises a metal active component, a carrier, a first auxiliary agent and a second auxiliary agent, wherein the metal active component is one or more of Fe, co or Ni; the carrier is a mixed oxide or a composite oxide formed by one or more of Al2O3, siO2, zrO2, tiO2 and MgO; the first auxiliary agent is a structural auxiliary agent and is one or more of Zn, cu, sn, in or Cd; the second auxiliary agent is one or a mixture of more of alkali metal oxide or alkaline earth metal oxide. The active component of the catalyst is non-noble metal element, which has no adverse effect on environment, the selectivity of the target product olefin is high, the carbon deposit is greatly reduced, and the stability of the catalyst is good.

CN105085143a discloses a method for producing ethylene propylene by mixing carbon five-carbon hexaalkane and carbon four. The raw material rich in carbon five-carbon hexaalkane is firstly fed into a reactor filled with a dehydrogenation catalyst to carry out alkane dehydrogenation reaction under the conditions of 480-700 ℃ of temperature, 0.01-3 MPa of pressure and 0.1-10 h < -1 > of volume airspeed, and the dehydrogenation product is mixed with carbon four-hydrocarbon and then fed into the reactor filled with a catalytic cracking catalyst to carry out catalytic cracking reaction under the conditions of 450-650 ℃ of temperature, 0.1-0.3 MPa of pressure and 0.1-10 h < -1 > of volume airspeed. The method can improve the yield of ethylene and propylene and reduce the energy consumption.

Although the above technology can improve the yield of ethylene and propylene from carbon tetrahydrocarbon, there are also great problems such as: the catalytic cracking of the carbon tetrahydrocarbon is only suitable for the carbon tetrahydrocarbon with higher olefin content, and is difficult to effectively convert the raw material with higher alkane content; dehydrogenation of the tetraalkane only converts the tetraalkane into tetraalkene, and more ethylene and propylene cannot be obtained; the combined process of catalytic dehydrogenation and catalytic cracking needs to be provided with a dehydrogenation reactor and a cracking reactor respectively, and completely different catalysts are used, so that the process is complex, the yields of ethylene and propylene are low, and the energy consumption is high.

It is noted that the information disclosed in the foregoing background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention aims at overcoming the defects of the prior art and providing a catalyst with catalytic hydrogenation performance and catalytic cracking performance so as to improve the yield of ethylene and propylene in the process of producing ethylene and propylene from carbon tetrahydrocarbon.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a dehydrogenation cracking catalyst, which comprises 10-70% of carrier, 10-60% of molecular sieve, 1-40% of metal active component and 10-50% of binder, wherein the molecular sieve is a molecular sieve with MFI structure, and the metal active component is one or more metals or metal oxides selected from Fe, ni, cr, mn, zn, pt and V.

In some embodiments, the dehydrogenation cracking catalyst comprises, by weight percent, 20 to 50% carrier, 20 to 50% molecular sieve, 1 to 20% metal active component, and 15 to 40% binder.

In some embodiments, the molecular sieve having an MFI structure is a ZSM molecular sieve or a modified ZSM molecular sieve, or a ZRP molecular sieve or a modified ZRP molecular sieve.

In some embodiments, the molecular sieve having an MFI structure has a silica to alumina ratio of 50 to 400, preferably 150 to 300.

In some embodiments, the carrier is selected from one or more of kaolin, montmorillonite, and bentonite.

In some embodiments, the binder is selected from one or more of a silica sol, an alumina sol, or pseudo-boehmite.

In another aspect, the present invention provides a method for preparing the above dehydrogenation cracking catalyst, comprising:

mixing the metal salt of the metal active component, the molecular sieve with the MFI structure and water to obtain first slurry, or dipping the soluble metal salt solution of the metal active component on the molecular sieve with the MFI structure, and then mixing with water to obtain first slurry;

mixing the carrier, the binder and water to obtain a second slurry; and

and mixing the first slurry with the second slurry, and washing, filtering, drying and roasting to obtain the dehydrogenation cracking catalyst.

In some embodiments, the metal salt is a nitrate, sulfate, chloride, or oxide.

In some embodiments, the solids content in the first slurry is 10 to 60w%, preferably 20 to 40w%.

In some embodiments, the solids content in the second slurry is 10 to 60w%, preferably 20 to 40w%.

In some embodiments, the drying temperature is 100 to 180 ℃, preferably 120 to 150 ℃, for 1 to 8 hours, preferably 3 to 5 hours, and the firing temperature is 600 to 800 ℃, preferably 650 to 750 ℃, for 2 to 10 hours, preferably 4 to 8 hours.

In yet another aspect, the present invention provides a process for producing ethylene and propylene from a carbon tetrahydrocarbon comprising:

and enabling the carbon tetrahydrocarbon to contact with the dehydrogenation cracking catalyst in a reactor for reaction to obtain ethylene and propylene.

In some embodiments, the carbon tetrahydrocarbons are carbon tetraalkanes and/or carbon tetraolefins.

In some embodiments, the carbon tetrahydrocarbons are selected from one or more of steam cracking byproduct carbon tetrahydrocarbons, catalytic cracking byproduct carbon tetrahydrocarbons, methanol-to-olefins byproduct carbon tetrahydrocarbons, and oilfield gas recovery carbon tetrahydrocarbons.

In some embodiments, the reaction temperature of the reaction is 450 to 700 ℃, preferably 550 to 650 ℃, the catalyst to oil ratio is 2 to 30, preferably 5 to 20, the reaction time is 0.5 to 10 seconds, preferably 1 to 5 seconds, and the reaction pressure is 0.1 to 0.6MPa, preferably 0.15 to 0.4MPa.

In some embodiments, the reactor is selected from the group consisting of a fixed bed reactor, a fluidized bed reactor, a moving bed reactor, a riser reactor, and a combination of one or more of a downer transport reactor.

In some embodiments, the method further comprises: and separating the reacted product, and returning the obtained C4-C8 hydrocarbon to the reactor for continuous reaction.

The dehydrogenation cracking catalyst of the invention is prepared by carrying out metal modification on a molecular sieve with an MFI structure, improves the catalytic dehydrogenation reaction performance on the basis of keeping the catalytic cracking performance, and achieves the effective coupling of the catalytic dehydrogenation reaction and the catalytic cracking reaction of the carbon tetrahydrocarbon in the process of producing ethylene and propylene by catalyzing the carbon tetrahydrocarbon, thereby improving the yield of the ethylene and the propylene.

Detailed Description

The technical scheme of the invention is further described below according to specific embodiments. The scope of the invention is not limited to the following examples, which are given for illustrative purposes only and do not limit the invention in any way.

In the present invention, any matters or matters not mentioned are directly applicable to those known in the art without modification except for those explicitly stated. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are all considered as part of the original disclosure or original description of the present invention, and should not be considered as new matters not disclosed or contemplated herein unless such combination would obviously be unreasonable to one skilled in the art.

All of the features disclosed in this invention may be combined in any combination which is understood to be disclosed or described in this invention unless the combination is obviously unreasonable by those skilled in the art. The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

According to one aspect of the present invention, there is provided a dehydrogenation cracking catalyst comprising a support, a molecular sieve, a metal active component, and a binder

The dehydrogenation cracking catalyst comprises, by weight percent, based on the dry weight of the catalyst, 10 to 70% of a carrier, 10 to 60% of a molecular sieve, 1 to 40% of a metal active component and 10 to 50% of a binder, preferably 20 to 50% of a carrier, 20 to 50% of a molecular sieve, 1 to 20% of a metal active component and 15 to 40% of a binder.

In the catalyst, the molecular sieve is a molecular sieve with an MFI structure, has a shape selective catalytic effect, is beneficial to the diffusion and reaction of carbon tetraolefins, and can be a ZSM molecular sieve or a modified ZSM molecular sieve or a ZRP molecular sieve or a modified ZRP molecular sieve.

The modified ZSM molecular sieve may be one or more of a ZSM molecular sieve containing rare earth, a ZSM molecular sieve containing phosphorus and alkaline earth metal, and a ZSM molecular sieve containing phosphorus and transition metal, preferably a ZSM molecular sieve containing phosphorus and rare earth.

The modified ZRP molecular sieve may be one or more of a ZRP molecular sieve containing rare earth, a ZRP molecular sieve containing phosphorus and alkaline earth metal, and a ZRP molecular sieve containing phosphorus and transition metal, preferably a ZRP molecular sieve containing phosphorus and rare earth.

In the catalyst of the invention, the silicon-aluminum ratio of the ZRP molecular sieve or the modified ZRP molecular sieve is 50-400, preferably 150-300.

In the catalyst of the present invention, the metal active component is a metal or metal oxide selected from one or more of Fe, ni, cr, mn, zn, pt and V, and these metal active components are good dehydrogenation active components. The metal active component may be impregnated onto the molecular sieve by a solution of a soluble metal salt or may be added directly during the preparation of the catalyst.

Through the combination of the molecular sieve with the MFI structure and the metal active components, the catalytic dehydrogenation reaction performance of the catalyst can be improved on the basis of retaining the catalytic cracking performance of the catalyst, and the effective coupling of the catalytic dehydrogenation reaction and the catalytic cracking reaction of the carbon four-hydrocarbon can be achieved.

In the catalyst of the invention, the carrier is clay, and is selected from one or more of kaolin, montmorillonite and bentonite.

In the catalyst of the invention, the binder is selected from one or more of silica sol, alumina sol or pseudo-boehmite.

The metal active component can be immersed on the molecular sieve through soluble metal salt solution in the preparation process of the dehydrogenation cracking catalyst, or can be directly added in the preparation process of the catalyst.

Wherein the impregnation process comprises formulating an impregnation solution of the metal component-containing compound, and thereafter impregnating the support with the solution. The impregnation method is a conventional method, and for example, may be an excess liquid impregnation method or a pore saturation method impregnation method. Wherein the specified level of catalyst can be prepared by adjusting and controlling the concentration, amount or amount of the impregnation solution containing the metal component, or the amount of the support, as will be readily understood and effected by those skilled in the art.

The manner of impregnating the metal active component may for example comprise the following steps:

impregnating a soluble metal salt solution of a metal active component on a molecular sieve with an MFI structure, and then mixing the molecular sieve with water to obtain a first slurry;

mixing the carrier, the binder and water to obtain second slurry; and

the first slurry and the second slurry are mixed, and then washed, filtered, dried and roasted to obtain the dehydrogenation cracking catalyst.

The manner of directly adding the metal active component may include, for example, the following steps:

mixing metal salt of a metal active component, a molecular sieve with an MFI structure and water to obtain first slurry;

mixing the carrier, the binder and water to obtain second slurry; and

The metal salt of the metal active component can be nitrate, sulfate, chloride or oxide, etc., and can be added with deionized water for pulping and stirring after being uniformly mixed with the molecular sieve with the MFI structure, thus obtaining the first slurry with the solid content of 10-60 w percent, preferably 20-40 w percent.

The carrier and the binder can be uniformly mixed and then added with deionized water for pulping and stirring uniformly to obtain second slurry with the solid content of 10-60 w percent, preferably 20-40 w percent.

The first slurry and the second slurry are mixed and pulped, and then spray-dried, washed and filtered in sequence, and then dried for 1-8 hours, preferably 3-5 hours, at a temperature of 100-180 ℃, preferably 120-150 ℃, and then baked for 2-10 hours, preferably 4-8 hours, at a temperature of 600-800 ℃, preferably 650-750 ℃ to obtain the required catalyst.

The dehydrogenation cracking catalyst of the invention improves the reaction performance of catalytic dehydrogenation on the basis of keeping the catalytic cracking performance, achieves effective coupling of catalytic dehydrogenation and catalytic cracking reaction of the carbon tetrahydrocarbon in the process of producing ethylene and propylene by catalyzing the carbon tetrahydrocarbon, and the specific production process can comprise the following steps:

the carbon tetrahydrocarbon and the dehydrogenation cracking catalyst of the invention are contacted in a reactor to react to obtain ethylene and propylene.

The carbon tetrahydrocarbon treated by the method is the carbon tetraalkane and/or the carbon tetraalkene, namely the carbon tetraalkane and/or the carbon tetraalkene can be the carbon tetraalkane, the carbon tetraalkene can be the carbon tetraalkene, and the mixture of the carbon tetraalkane and the carbon tetraalkene in any proportion can be adopted.

The carbon tetrahydrocarbon treated by the method is one or more selected from the group consisting of steam cracking byproduct carbon tetrahydrocarbon, catalytic cracking byproduct carbon tetrahydrocarbon, methanol-to-olefin byproduct carbon tetrahydrocarbon and oilfield gas recovery carbon tetrahydrocarbon, and is applicable to various raw material gases.

In the process for producing ethylene and propylene from a carbon tetrahydrocarbon of the present invention, the reaction temperature of the reaction is 450 to 700 ℃, preferably 550 to 650 ℃, the catalyst to oil ratio (i.e., the ratio of the catalyst circulation amount to the total feed amount of the carbon tetrahydrocarbon) is 2 to 30, preferably 5 to 20, the reaction time is 0.5 to 10 seconds, preferably 1 to 5 seconds, and the reaction pressure is 0.1 to 0.6MPa, preferably 0.15 to 0.4MPa.

The reactor used in the present invention is selected from one or more of a fixed bed reactor, a fluidized bed reactor, a moving bed reactor, a riser reactor and a downer reactor.

In order to make the reaction more complete and the yield of ethylene and propylene higher, the product obtained after the reaction can be separated, wherein the C4-C8 hydrocarbon obtained by separation is returned to the reactor for continuous reaction.

In addition, an inert gas may be introduced into the reactor as a carrier gas, and the inert gas used in the present invention is selected from one or more of water vapor, nitrogen, dry gas, preferably water vapor.

The process of the invention can achieve higher conversion capacity of the four carbon hydrocarbons and higher yields of ethylene and propylene.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

Examples

Reagents, instruments and tests

In the examples and comparative examples of the present invention, the gas products were tested by the petrochemical analysis method RIPP 77-90 and the coke content was measured by the petrochemical analysis method RIPP 107-90.

In the examples below, the conversion of the carbon tetrahydrocarbons and the yields of ethylene and propylene were calculated according to the following formulas:

the RIPP petrochemical analysis method is selected from the group consisting of petrochemical analysis method (RIPP test method), and the like, edited by Yang Cuiding, scientific Press, 1990.

The reagents used hereinafter are all chemically pure reagents unless otherwise specified.

The molecular sieves with MFI structure are all produced by Qilu catalyst factories, and the industrial marks are:

ZRP-1: wherein SiO is ₂ /Al ₂ O ₃ ＝150，Na ₂ The content of O is 0.17wt%, and the rare earth oxide Re ₂ O ₃ The content of (2) was 1.4wt%, in which the content of lanthanum oxide was 0.84wt%, the content of cerium oxide was 0.18wt%, and the content of other rare earth oxides was 0.38wt%.

ZSM-5 molecular sieve: wherein SiO is ₂ /Al ₂ O ₃ ＝180，Na ₂ The O content was 0.12wt%.

USY molecular sieve: wherein SiO is ₂ /Al ₂ O ₃ ＝150，Na ₂ The content of O is 0.15wt%, and the rare earth oxide Re ₂ O ₃ The content of (2) was 1.0wt%, the content of lanthanum oxide was 0.62wt%, the content of cerium oxide was 0.21wt%, and the content of other rare earth oxides was 0.27wt%.

Metal salt: fe (NO) ₃ ) ₃ ·9H ₂ O、Ni(NO ₃ ) ₂ ·6H ₂ O、Zn(NO ₃ ) ₂ ·6H ₂ O、Mn(NO ₃ ) ₄ ·4H ₂ O、Cr(NO ₃ ) ₃ ·9H ₂ O、FeCl ₃ ·6H ₂ O、NiCl ₂ ·6H ₂ O、ZnCl ₂ ·4H ₂ O、MnCl ₂ ·4H ₂ O、CrCl ₃ ·6H ₂ O、PtCl ₄ 、VCl ₃ 。

Kaolin: industrial product of kaolin company, sozhou, with a solids content of 76% by weight;

aluminum sol: qilu catalyst plant production, al thereof ₂ O ₃ The content is 21.5wt%;

silica sol: production of Beijing chemical plant, siO thereof ₂ The content is 16.0wt%;

pseudo-boehmite produced by Shandong Albah.

Example 1

60g of ZRP-1 molecular sieve and 21.7g of Fe (NO) ₃ ) ₃ ·9H ₂ Mixing the O evenly, adding 160g of deionized water, pulping, and stirring evenly to obtain molecular sieve slurry;

mixing 75g of kaolin and 3.3g of aluminum sol uniformly, adding 300 deionized water, pulping, and stirring uniformly to obtain carrier slurry;

adding molecular sieve slurry into carrier slurry, mixing and pulping, then sequentially carrying out spray drying, washing and filtering, then drying for 4 hours at 120 ℃ and roasting for 6 hours at 700 ℃ to obtain the catalyst Cat-M1.

Example 2

The procedure of example 1 was followed, except that 14.9g of Ni (NO ₃ ) ₂ ·6H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M2.

Example 3

The procedure of example 1 was followed, except that 13.7g of Zn (NO ₃ ) ₂ ·6H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M3.

Example 4

The procedure of example 1 was followed, except that 20.5g of Mn (NO ₃ ) ₄ ·4H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M4.

Example 5

The procedure of example 1 was followed, except that 23.1g of Cr (NO ₃ ) ₃ ·9H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M5.

Example 6

The procedure of example 1 was followed except that 14.5g of FeCl was taken ₃ ·6H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, getTo catalyst Cat-M6.

Example 7

The procedure of example 1 was followed except that 14.0g of NiCl was taken ₂ ·6H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M7.

Example 8

The procedure of example 1 is followed, except that 9.6g of ZnCl is taken ₂ ·4H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M8.

Example 9

The procedure of example 1 was followed except that 10.8g of MnCl was taken ₂ ·4H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M9.

Example 10

The procedure of example 1 was followed, except that 15.4g of CrCl was taken ₃ ·6H ₂ O replaces Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M10.

Example 11

The procedure of example 1 was followed, except that 5.2g of PtCl was taken ₄ Instead of Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M11.

Example 12

The procedure of example 1 was followed except that 9.3g of VCl was taken ₃ Instead of Fe (NO) in example 1 ₃ ) ₃ ·9H ₂ O, to obtain catalyst Cat-M12.

Examples 13 to 24

The procedure of examples 1-12 was followed except that ZSM-5 molecular sieves of the same mass were used in place of the ZRP-1 molecular sieves of examples 1-12 to give catalysts Cat-M13-Cat-M24.

Comparative example 1

60g of ZRP-1 molecular sieve and 12.8g of Mg (NO ₃ ) ₂ ·9H ₂ Mixing O uniformly, adding 160g deionized water, pulping, stirringHomogenizing to obtain molecular sieve slurry;

adding molecular sieve slurry into carrier slurry, mixing and pulping, then sequentially carrying out spray drying, washing and filtering, then drying for 4 hours at 120 ℃ and roasting for 6 hours at 700 ℃ to obtain the catalyst Cat-D1.

Comparative example 2

60g of USY molecular sieve and 21.7g of Fe (NO) ₃ ) ₃ ·9H ₂ Mixing the O evenly, adding 160g of deionized water, pulping, and stirring evenly to obtain molecular sieve slurry;

adding molecular sieve slurry into carrier slurry, mixing and pulping, then sequentially carrying out spray drying, washing and filtering, then drying for 4 hours at 120 ℃ and roasting for 6 hours at 700 ℃ to obtain the catalyst Cat-D2.

Application example

The catalysts of the above examples and comparative examples were subjected to evaluation tests, the test materials being C4 cuts obtained from a catalytic cracker, and the compositions thereof are shown in Table 1.

The evaluation test specifically includes:

the C4 fraction was reacted by contacting the catalyst obtained in the above examples and comparative examples in a small fixed fluidized bed reactor at a reaction temperature of 600℃and a weight hourly space velocity of 4h ^-1 The catalyst-to-oil ratio was 10, the reaction time was 3 seconds, the reaction pressure was 0.16MPa, and the pre-reduction treatment with hydrogen was performed before the reaction to maintain the catalyst surface active component in a metallic state.

The catalyst was used in an amount of 160g and the carbon tetrahydrocarbon was used in an amount of 16g per test. In the evaluation test, water vapor was used as a carrier gas.

The gas products obtained by the reaction were tested, and the evaluation results thereof are shown in tables 2 to 6, respectively.

TABLE 1 composition of C4 fraction

Project	Mass fraction, percent
		N-butane	6.77
Isobutane	16.5
		N-butene	15.1
Isobutene (i-butene)	30.3
		Fumaric acid	17.1
Maleic anhydride	13.8
		1,3 butadiene	0.43
Totalizing	100

Table 2 evaluation results of examples 1 to 6

TABLE 3 evaluation results of examples 7-12

TABLE 4 evaluation results of examples 13-18

TABLE 5 evaluation results of examples 19-24

Table 6 evaluation results of comparative examples 1 to 2

From the evaluation results of tables 2 to 6, it is apparent that the use of the dehydrogenation cracking catalyst of the present invention in a process for producing ethylene and propylene from carbon tetrahydrocarbons can improve the conversion of carbon tetrahydrocarbons and thus the yields of ethylene and propylene.

It will be appreciated by persons skilled in the art that the embodiments described herein are merely exemplary and that various other alternatives, modifications and improvements may be made within the scope of the invention. Thus, the present invention is not limited to the above-described embodiments, but only by the claims.

Claims

1. A dehydrogenation cracking catalyst for producing ethylene and propylene from carbon tetrahydrocarbon, which is characterized by comprising, by weight, 10-70% of a carrier, 10-60% of a molecular sieve, 1-40% of a metal active component and 10-50% of a binder, wherein the molecular sieve is a molecular sieve with an MFI structure, and the metal active component is one or more metals or metal oxides selected from Fe, ni, cr, mn, zn, pt and V;

the molecular sieve with the MFI structure is a ZSM molecular sieve or a modified ZSM molecular sieve, or a ZRP molecular sieve or a modified ZRP molecular sieve;

the carbon tetrahydrocarbon is a carbon tetraalkane and/or a carbon tetraalkene;

the carrier is selected from one or more of kaolin, montmorillonite and bentonite;

the binder is selected from one or more of silica sol, alumina sol or pseudo-boehmite.

2. The dehydrogenation cracking catalyst of claim 1, wherein the dehydrogenation cracking catalyst comprises, by weight percent, 20-50% support, 20-50% molecular sieve, 1-20% metal active component, and 15-40% binder.

3. The dehydrogenation cracking catalyst of claim 1, wherein the molecular sieve having MFI structure has a silica to alumina ratio of 50 to 400.

4. The dehydrogenation cracking catalyst of claim 3, wherein the molecular sieve having an MFI structure has a silica to alumina ratio of 150 to 300.

5. The method for producing a dehydrogenation cracking catalyst according to any one of claims 1 to 4, characterized by comprising:

mixing the carrier, the binder and water to obtain a second slurry; and

6. The method of claim 5, wherein the metal salt is a nitrate, sulfate, chloride or oxide.

7. The method according to claim 5, wherein the solid content in the first slurry is 10 to 60w%.

8. The method according to claim 7, wherein the solid content in the first slurry is 20 to 40w%.

9. The method according to claim 5, wherein the solid content in the second slurry is 10 to 60w%.

10. The method according to claim 9, wherein the solid content in the second slurry is 20 to 40w%.

11. The method according to claim 5, wherein the drying temperature is 100 to 180 ℃ for 1 to 8 hours, and the baking temperature is 600 to 800 ℃ for 2 to 10 hours.

12. The method according to claim 11, wherein the drying temperature is 120 to 150 ℃ for 3 to 5 hours, and the firing temperature is 650 to 750 ℃ for 4 to 8 hours.

13. A process for producing ethylene and propylene from a carbon tetrahydrocarbon comprising:

contacting a carbon tetrahydrocarbon with a dehydrogenation cracking catalyst according to any one of claims 1-4 in a reactor to react to obtain ethylene and propylene.

14. The method of claim 13, wherein the carbon tetrahydrocarbons are selected from one or more of steam cracking byproduct carbon tetrahydrocarbons, catalytic cracking byproduct carbon tetrahydrocarbons, methanol-to-olefins byproduct carbon tetrahydrocarbons, and oilfield gas recovery carbon tetrahydrocarbons.

15. The method according to claim 13, wherein the reaction temperature is 450-700 ℃, the catalyst-to-oil ratio is 2-30, the reaction time is 0.5-10 seconds, and the reaction pressure is 0.1-0.6 MPa.

16. The method according to claim 15, wherein the reaction temperature is 550-650 ℃, the catalyst to oil ratio is 5-20, the reaction time is 1-5 seconds, and the reaction pressure is 0.15-0.4 MPa.

17. The method of claim 13, wherein the reactor is selected from one or more of a fixed bed reactor, a fluidized bed reactor, a moving bed reactor, a riser reactor, and a downer reactor.

18. The method of claim 13, wherein the method further comprises: and separating the reacted product, and returning the obtained C4-C8 hydrocarbon to the reactor for continuous reaction.