CN112723971A

CN112723971A - Method for producing ethylene and propylene from carbon-tetrahydrocarbon

Info

Publication number: CN112723971A
Application number: CN201911030045.2A
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: 2019-10-28
Filing date: 2019-10-28
Publication date: 2021-04-30
Anticipated expiration: 2039-10-28
Also published as: CN112723971B

Abstract

The invention relates to the field of ethylene and propylene production by using C-tetrahydrocarbon, and discloses a method for producing ethylene and propylene by using C-tetrahydrocarbon. The method comprises the following steps: the method comprises the following steps of (1) contacting a carbon four-hydrocarbon with a fluidized catalyst in a fluidized bed reactor to perform catalytic reaction, wherein the carbon four-hydrocarbon comprises the carbon four-hydrocarbon and carbon four-olefin, and the mass fraction of the carbon four-hydrocarbon in the carbon four-hydrocarbon is not less than 30%; the catalyst comprises a substrate, an active component and a binder; based on the total weight of the catalyst, the content of the matrix is 10-70 wt%, the content of the active component is 10-70 wt%, and the content of the binder is 10-50 wt%; the active component comprises a molecular sieve with MFI structure and a metal active component, the metal active component is selected from at least one metal or oxide of Fe, Ni, Cr, Mn, Pt, Mg and V elements, wherein the weight of the metal active component is 0.5-15 wt% of the molecular sieve. Can realize the conversion of the carbon tetrahydrocarbon with high alkane content into the ethylene and the propylene, and has high product yield.

Description

Method for producing ethylene and propylene from carbon-tetrahydrocarbon

Technical Field

The invention relates to the field of ethylene and propylene production by using C-tetrahydrocarbon, in particular to a method for producing ethylene and propylene by using C-tetrahydrocarbon.

Background

The main sources of the carbon-four hydrocarbon comprise a catalytic cracking device byproduct carbon four, a steam cracking device byproduct carbon four and an oil field recovered carbon four. In recent years, with the development of coal chemical industry, a large amount of carbon tetrahydrocarbons are produced in the process of producing olefins from methanol.

In China, the comprehensive utilization rate of the carbon-tetrahydrocarbon is low, most of the carbon-tetrahydrocarbon is used as industrial or civil fuel, and less than 40 percent of the carbon-tetrahydrocarbon is used for producing gasoline blending components such as alkylate oil, methyl tert-butyl ether (MTBE) and the like and chemical products such as resin, rubber, fiber and the like. With the vigorous popularization of ethanol gasoline in China, the use of MTBE is limited, and moreover, because some chemical industry refineries do not have matched alkylation devices, more carbon tetrahydrocarbons cannot be efficiently utilized. The ethylene and propylene markets develop rapidly, the apparent consumption thereof increases year by year, and the supply and demand relationship is tense. The method for producing the ethylene and the propylene by using the C-tetrahydrocarbon as the raw material not only can solve the problem of low comprehensive utilization rate of the C-tetrahydrocarbon, but also can relieve the market conflict of the ethylene and the propylene.

At present, catalytic cracking technologies for carbon tetraolefins have been developed by various companies at home and abroad, mainly including UOP & Atofina's OCP technology, Lurgi's pylur technology, Mobil's MOI technology, KBR's Superflex technology, and petrochemical shanghai petrochemical research institute's OCC technology. These catalytic cracking techniques are relatively mature, the reaction conditions are moderate, the yields of ethylene and propylene exceed 50% or more, and the disadvantages are that the raw materials with higher tetrakane content cannot be treated, and the reaction-regeneration process cannot be continuously carried out when a fixed bed reactor is used. The catalytic cracking of the tetrakacarbon is still in the laboratory stage.

CN1506342A discloses a method for producing propylene by catalytic cracking olefin of four carbon atoms and above. The method adopts ZSM type molecular sieve loaded with at least one alkaline earth metal of Mg, Ca or Ba as a catalyst, olefin with four or more than four carbon atoms as a reaction raw material is reacted at the reaction temperature of 400-^-1The cleavage reaction takes place under conditions. The method can obviously improve the selectivity and yield of the propylene.

CN106608789A discloses a method for producing propylene by catalytic cracking of carbon tetraolefin. The method comprises the steps of adopting the raffinate carbon four as a raw material, forming ZSM-5 molecular sieve raw powder with the shape index of 3-100, then carrying out alkali treatment to obtain the molecular sieve catalyst with a composite pore channel structure, and carrying out alkali treatment at the reaction temperature of 400 ℃ and 600 ℃, the reaction pressure of 0-0.3MPa and the weight hourly space velocity of 1-50h^-1Under the conditions of (1). The method can obviously improve the stability of the catalyst and the selectivity of propylene.

CN105085143A discloses a method for producing ethylene and propylene by mixing C five-carbon hexaalkane and C four. The raw material rich in carbon penta-hexaalkane is firstly put into a reactor filled with dehydrogenation catalyst at the temperature of 480 ℃ and 700 ℃, the pressure of 0.01-3MPa and the volume space velocity of 0.1-10h^-1The dehydrogenation reaction of alkane is carried out under the condition, the dehydrogenation product and the carbon tetrahydrocarbon are mixed and then enter a reactor filled with a catalytic cracking catalyst, the temperature is 450-^-1The catalytic cracking reaction is carried out under the condition. The method can improve the yield of ethylene and propylene and reduce energy consumption.

CN107735387A discloses a system and a process for producing propylene. The method adopts two reactors connected in series, and a double decomposition catalyst and a cracking catalyst are loaded respectively, or a double decomposition catalyst and a cracking catalyst are loaded in one reactor in series. Wherein the metathesis catalyst is mesoporous silica impregnated with metal oxide, and the cracking catalyst is MFI structured silica. The material flow containing butylene respectively carries out metathesis reaction and cracking reaction to be converted into ethylene and propylene, wherein the ethylene can be used as a first circulating material flow to be mixed with the material flow containing butylene and then carries out metathesis reaction and cracking reaction again, and the material flow rich in butylene in the reaction product can be used as a second circulating material flow to carry out metathesis reaction and cracking reaction again. The method can obtain higher propylene yield.

Although the above techniques can improve the yields of ethylene and propylene produced from the tetracarbon, they have a significant problem. In the prior art, the catalytic cracking of the carbon-tetrahydrocarbon is only suitable for the carbon-tetrahydrocarbon with higher olefin content, and the raw material with higher alkane content is difficult to effectively convert; dehydrogenation of a tetraalkyl hydrocarbon merely converts the tetraalkyl hydrocarbon to a tetraolefin and does not effectively couple alkane dehydrogenation and olefin cracking to yield more ethylene and propylene.

Disclosure of Invention

The invention aims to overcome the problems in the production of ethylene and propylene from the hydrocarbon tetrads, and provides a method for producing the ethylene and the propylene from the hydrocarbon tetrads, which can process the hydrocarbon tetrads with high alkane content and obtain higher yields of the ethylene and the propylene.

In order to achieve the above object, the present invention provides a method for producing ethylene and propylene from a hydrocarbon comprising: contacting a carbon-four hydrocarbon, water vapor and a fluidized catalyst in a fluidized bed reactor for catalytic reaction, wherein the carbon-four hydrocarbon comprises a carbon-four hydrocarbon and a carbon-four olefin, and the mass fraction of the carbon-four hydrocarbon in the carbon-four hydrocarbon is not less than 30%;

the catalyst comprises a substrate, an active component and a binder; based on the total weight of the catalyst, the content of the matrix is 10-70 wt%, the content of the active component is 10-70 wt%, and the content of the binder is 10-50 wt%;

the active component comprises a molecular sieve having an MFI structure and a metal active component selected from a metal or oxide of at least one of the elements Fe, Ni, Cr, Mn, Pt, Mg and V, wherein the weight of the metal active component is from 0.5 to 15 wt% of the molecular sieve.

Through the technical scheme, the invention can realize that the fluid catalytic method converts the carbon tetrahydrocarbon with high carbon tetrahydrocarbon content into ethylene and propylene, and has high product yield. The composition of the catalyst used therein is favorable for realizing the high yield of ethylene and propylene from the four-carbon hydrocarbon with high alkane content. In the results provided in example 3 of the present invention, when a tetracarbon having a maximum tetracarbon content of 54.16 wt% was treated, the conversion of the tetracarbon was 72.02%, the yield of ethylene + propylene was 63.72%, and the selectivity of ethylene + propylene was 88.48%. Whereas comparative example 3 had a carbon tetracarbon conversion of 56.51%, an ethylene + propylene yield of 48.43%, and an ethylene + propylene selectivity of only 85.70%. The method provided by the invention has better effect of converting the carbon four hydrocarbon into the ethylene and the propylene.

Drawings

FIG. 1 is a schematic flow diagram of a system and process for producing ethylene and propylene from a tetracarbon hydrocarbon according to the present invention.

Description of the reference numerals

11-catalyst riser 12-stripper 13-reactor

14-settler 15-combustion plant 16-regenerator

101-tetracarbon 102-lift gas 103-stripping steam

104-reaction oil gas 105-combustion-supporting gas 106-regeneration flue gas

107-spent agent conveying pipe 108-regeneration inclined pipe

2-first-stage separation device 201-dry gas component 202-liquefied gas component

3-ethylene separation unit 301-light hydrocarbon component 302-ethylene-rich component

303-ethane-rich component

4-propylene separation unit 401-propylene rich component 402-heavy hydrocarbon component

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a method for producing ethylene and propylene from carbon-tetrad hydrocarbon, which comprises the following steps:

contacting a carbon-four hydrocarbon, water vapor and a fluidized catalyst in a fluidized bed reactor for catalytic reaction, wherein the carbon-four hydrocarbon comprises a carbon-four hydrocarbon and a carbon-four olefin, and the mass fraction of the carbon-four hydrocarbon in the carbon-four hydrocarbon is not less than 30%;

The method provided by the invention can be used for producing ethylene and propylene by catalytic conversion of the carbon-tetrahydrocarbon material with high carbon-tetrahydrocarbon content in the fluidized bed reactor through fluidized catalytic reaction, and has higher adaptability for processing the carbon-tetrahydrocarbon material. It is known that the prior conventional technical means cannot easily realize the high yield of ethylene and propylene of the carbon tetracarbon material with high carbon tetracarbon content. Generally, the olefin content of the C-tetrahydrocarbon is high, so that the C-tetrahydrocarbon is easier to produce ethylene and propylene. The method provided by the invention can also be used for producing ethylene and propylene from the carbon-four hydrocarbon material when the olefin content in the carbon-four hydrocarbon is high.

The present invention provides an embodiment of the method, preferably, the mass fraction of the tetraarbon in the tetraarbon is not less than 50%. The method provided by the invention can realize the production of ethylene and propylene from the C-tetrahydrocarbon with higher C-tetrahydrocarbon content, and has the advantages of higher C-tetrahydrocarbon conversion rate, better selectivity and higher ethylene and propylene yield.

In the invention, the catalyst can better catalyze and convert the tetrakacarbon to generate the ethylene and the propylene, and realizes that the tetrakacarbon raw material with high tetrakacarbon content is converted to generate the ethylene and the propylene more. Preferably, the present invention provides an embodiment of the process, the molecular sieve having the MFI structure is a modified or unmodified ZSM-5 molecular sieve; preferably, the ZSM-5 molecular sieve has a Si/Al molar ratio of 100-300: 1. ZRP molecular sieves are commercially available. The ZRP molecular sieve may contain rare earth elements, such as La and/or Ce, preferably in an amount of 0.1-2 wt% of the ZRP molecular sieve.

In one embodiment of the present invention, the catalyst comprises active components, and further preferably comprises metal active components including a metal or oxide of Cr element and optionally a metal or oxide of Fe and/or V element; preferably, the content of Fe element is 0-5 wt%, preferably 0.2-1 wt%, the content of Cr element is 0.5-8 wt%, preferably 0.8-2 wt%, and the content of V element is 0-15 wt%, preferably 3-8 wt% of the molecular sieve.

In the present invention, it is preferred in one embodiment that the metallic active component is supported on the outer surface of the molecular sieve having the MFI structure.

In the present invention, the matrix may serve as a substrate for supporting the active ingredient. Preferably, the matrix is selected from at least one of kaolin, montmorillonite and bentonite.

In the present invention, the bonding between the matrix and the active component may be strengthened by a binder contained to better exert the effect of the active component on the catalytic reaction, and preferably, the binder is at least one selected from the group consisting of silica sol, aluminum sol, and pseudo-boehmite.

In the invention, the catalyst can be prepared by the following method:

(i) impregnating a soluble metal salt solution into a molecular sieve with an MFI structure, or carrying out ion exchange on the soluble metal salt solution and the molecular sieve with the MFI structure, and drying and roasting to obtain an active component;

(ii) mixing the active component with water to obtain molecular sieve slurry; mixing a substrate, a binder and water to obtain a carrier slurry;

(iii) mixing the molecular sieve slurry and the carrier slurry, and then drying, washing, filtering, drying and roasting to obtain an oxidation state catalyst;

(iv) the oxidation state catalyst is partially reduced to obtain the catalyst;

wherein the metal salt comprises a water-soluble salt of the element Cr, and optionally a water-soluble salt of the element Fe and/or V; the molecular sieve with MFI is a modified or unmodified ZSM-5 molecular sieve; preferably, the ZSM-5 molecular sieve has a Si/Al molar ratio of 100-300: 1. ZRP molecular sieves are commercially available. The ZRP molecular sieve may contain rare earth elements, such as La and/or Ce, preferably in an amount of 0.1-2 wt% of the ZRP molecular sieve.

In the present invention, step (iv) may be performed during the preparation of the catalyst, or in the method provided by the present invention, the in-line reduction may be performed by contacting the oxidized catalyst with a reducing gas for partial reduction.

In some embodiments of the present invention, the reducing gas may be a light hydrocarbon component or an ethylene-rich component separated from the product of the catalytic reaction.

In some embodiments of the invention, the reducing gas may be used as a lift gas for the catalyst to complete the lifting, fluidization and partial reduction of the oxidized catalyst in the riser of the fluidized bed reactor.

In some embodiments of the present invention, the prepared oxidation state catalyst is introduced into a regenerator to be mixed with a balancing agent and/or a spent agent, and is transported to a riser after a regeneration reaction, fluidized under the carrying of a lift gas, and partially reduced to obtain the fluidized state catalyst. In the present invention, the oxidation state catalyst and the fluidized state catalyst are identical in all components except that the metal active component is not completely in the same form. An oxidation state catalyst compared to the fluidized state catalyst, wherein the active component comprises an oxide of at least one element selected from the group consisting of Fe, Ni, Cr, Mn, Pt, Mg and V; after undergoing partial reduction, the active component comprises a metal or oxide of at least one element selected from the group consisting of Fe, Ni, Cr, Mn, Pt, Mg and V, into the fluidized catalyst.

In the invention, the catalyst is suitable for fluidized catalytic reaction, the catalyst is granular, and the average particle diameter of the catalyst is 40-120 mu m.

The catalyst provided by the invention can promote the high-content C-tetrahydrocarbon to be catalytically converted into ethylene and propylene more, and the components contained in the catalyst utilize the combined action of various reactions in the catalytic reaction process to realize the high yield of ethylene and propylene. Preferably, the catalytic reaction comprises a catalytic cracking reaction and a catalytic dehydrogenation reaction of the tetracarbon hydrocarbon performed simultaneously.

In some embodiments provided herein, the catalytic reaction conditions favor the catalytic conversion of the tetraalkyl hydrocarbon to yield more ethylene and propylene. Preferably, the conditions of the catalytic reaction include: the temperature is 450-700 ℃, preferably 550-650 ℃; the agent-oil ratio is 2-30, preferably 5-20; the reaction time is 0.5 to 10 seconds, preferably 1 to 5 seconds; the reaction pressure is 0.1-0.6MPa, preferably 0.15-0.4 MPa; the amount of steam used is 1 to 50 wt%, preferably 5 to 30 wt%, based on the amount of the hydrocarbon tetracarbonate added. Wherein, the catalyst-to-oil ratio refers to the mass ratio of the catalyst to the carbon-tetrahydrocarbon.

In some embodiments provided herein, the method further comprises: separating the product obtained by the catalytic reaction to obtain a light hydrocarbon component, an ethylene-rich component, an ethane-rich component, a propylene-rich component and a heavy hydrocarbon component; regenerating the catalyst and returning to the catalytic reaction; combusting the light hydrocarbon component and the ethane-rich component to generate heat for the regeneration and the catalytic reaction; returning the heavy hydrocarbon components to the catalytic reaction.

In some embodiments provided herein, preferably, the fluidized catalyst is obtained by subjecting an oxidation-state catalyst to a lift and reduction by a lift gas, wherein the lift gas is a light hydrocarbon component or an ethane-rich component. Wherein the light hydrocarbon component comprises hydrogen and methane. The mass fraction of ethane in the ethane-rich component is not less than 99.5%.

In the present invention, the heavy hydrocarbon component comprises C_4-8The hydrocarbon of (1). The yield of the heavy hydrocarbon component is low and can preferably be returned to the catalytic reaction. Because the amount of the heavy hydrocarbon component is small, the composition relation of alkane and olefin in the four-carbon hydrocarbon of the raw material is not influenced. Preferably, the amount of heavy hydrocarbon components returned is up to 10 wt% of the tetracarbon.

In the method provided by the invention, preferably, the regeneration temperature is 660-720 ℃, preferably 680-700 ℃; preferably, the regeneration process introduces a combustion gas, preferably selected from one or more of air, oxygen and other gases having an oxidizing effect, preferably air. The regeneration process is carried out in a regenerator.

The final product obtained by the method provided by the invention comprises the following components: hydrogen, methane, ethane, ethylene, and propylene.

FIG. 1 is a schematic diagram of a system and a flow chart for implementing the method.

The system comprises a reaction regeneration unit and a separation unit. Wherein, the reaction regeneration unit comprises a catalyst riser 11, a stripper 12, a reactor 13, a settler 14, a combustion device 15 and a regenerator 16; the separation unit comprises a first-stage separation device 2, an ethylene separation device 3 and a propylene separation device 4;

wherein, the stripper 12, the reactor 13 and the settler 14 are arranged in series in the order from bottom to top, the catalyst riser 11 is arranged in the stripper 12, and the outlet of the catalyst riser 11 extends into the bottom of the reactor 13 from bottom to top;

the bottom of the catalyst riser 11 is communicated with a regenerator 16 and a lifting gas 102 through a regeneration inclined pipe 108, the lifting gas 102 lifts the oxidation state catalyst from the regenerator 16 for fluidization and partial reduction, and the obtained fluidization state catalyst enters a reactor 13;

the bottom of the stripper 12 is filled with stripping steam 103 for stripping the catalyst after catalytic reaction to remove reaction oil gas carried on the catalyst, so as to obtain a spent catalyst; meanwhile, the bottom of the stripper 12 is communicated with the bottom of the regenerator 16 through a spent agent conveying pipe 107 and is used for conveying a spent agent into the regenerator 16 for regeneration;

the reactor 13 is used for contacting the carbon tetrahydrocarbon 101, the water vapor and the fluidized catalyst from the catalyst riser 11 to perform catalytic reaction;

the top of the settler 14 is communicated with a separation unit, and reaction oil gas 104 generated by catalytic reaction is introduced into the primary separation device 2;

the combustion device 15 is communicated with the regenerator 16 and the ethylene separation device 3, the ethane-rich component 303 and the light hydrocarbon component 301 obtained by the separation unit are introduced into the combustion device 15 for combustion, and the generated heat is introduced into the regenerator 16 to provide heat for catalyst regeneration and catalytic reaction;

the regenerator 16 converts the regenerated spent catalyst into an oxidation state catalyst, returns to the catalyst riser 11 and discharges regenerated flue gas 106;

in the separation unit, the first-stage separation device 2 is also communicated with an ethylene separation device 3 and a propylene separation device 4 and is used for separating the reaction oil gas 104 to obtain a dry gas component 201 and a liquefied gas component 202; the ethylene separation device 3 is used for separating the dry gas component 201 to obtain a light hydrocarbon component 301, an ethylene-rich component 302 and an ethane-rich component 303; the propylene separation device 4 is used for separating the liquefied gas component 202 to obtain a propylene-rich component 401 and a heavy hydrocarbon component 402; the propylene separation unit 4 is also in communication with reactor 13 for introducing the heavy hydrocarbon component 402 into reactor 13 or into reactor 13 after mixing with the tetracarbon 101.

The method for producing the ethylene and the propylene by the carbon-four hydrocarbon comprises the following implementation processes:

the tetracarbon 101 from the feed tank is preheated to 80-100 ℃ and then introduced into the reactor 13 together with the atomized steam; the oxidation state catalyst from the regenerator 16 is introduced into the catalyst riser 11 through the regeneration inclined tube 108, is lifted by the lifting gas 102 and is partially reduced into the fluidization state catalyst and then is introduced into the reactor 13, the carbon-tetrad hydrocarbon 101 and the water vapor are contacted with the fluidization state catalyst, and the catalytic reaction is carried out under the conditions that the reaction temperature is 450-700 ℃, preferably 550-650 ℃, the catalyst-oil ratio is 2-30, preferably 5-20, the reaction time is 0.5-10s, preferably 1-5s, and the reaction pressure is 0.1-0.6MPa, preferably 0.15-0.4MPa (the water vapor dosage is 1-50 wt%, preferably 5-30 wt% of the addition amount of the carbon-tetrad hydrocarbon);

separating an oil mixture obtained by catalytic reaction in a settler 14, feeding the catalyst obtained by separation after the reaction into a stripper 12, stripping by stripping steam 103 introduced from the bottom of the stripper 12 to remove reaction oil gas carried on the catalyst to obtain a spent catalyst, and introducing the reaction oil gas 104 into a separation unit for separation; the spent catalyst is introduced into the regenerator 16 through a spent catalyst delivery pipe 107, the combustion-supporting gas 105 is introduced into the regenerator 16, and the spent catalyst is regenerated under the conditions of the temperature of 660-720 ℃, preferably 680-700 ℃.

The reaction oil gas 104 is introduced into a first-stage separation device 2 for separation to obtain a dry gas component 201 containing carbon and less hydrocarbons and a liquefied gas component 202 containing carbon and more hydrocarbons. Wherein the dry gas component 201 is introduced into an ethylene separation device 3 for separation to obtain a light hydrocarbon component 301 rich in hydrogen and methane, an ethylene-rich component 302 and an ethane-rich component 303; the liquefied gas component 202 is introduced into a propylene separation device 4 for separation to obtain a propylene-rich component 401 and a heavy hydrocarbon component 402 rich in propane and carbon four hydrocarbons. Wherein, light hydrocarbon component 301 and rich ethane component 303 are introduced into burner 15, contact with combustion-supporting gas 16 and burn, the heat produced is introduced into regenerator 16, on the one hand, create the appropriate condition for catalyst regeneration, on the other hand, provide the heat for the reaction. The heavy hydrocarbon component 402 is introduced into reactor 13 as a recycle stream or mixed with the tetracarbon 101 and introduced into reactor 13 for catalytic reaction.

In the invention, the settling vessel 14 and the regenerator 16 are both provided with oil separating devices, which can separate reaction oil gas from spent catalyst and regeneration flue gas from oxidation state catalyst. The separation device is preferably a fast separation device, more preferably a cyclone.

In the present invention, the primary separation apparatus 2, the ethylene separation apparatus 3 and the propylene separation apparatus 4 are all separation apparatuses well known to those skilled in the art, and the operation methods thereof are also well known to those skilled in the art.

The method provided by the invention can achieve higher carbon four-hydrocarbon conversion capacity, higher ethylene and propylene yield and lower energy consumption.

In some embodiments provided by the present invention, the fluidized bed reactor comprises at least one of a fixed fluidized bed reactor, a bulk fluidized bed reactor, a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor, a transport bed reactor, and a dense phase fluidized bed reactor.

The following examples further illustrate the invention but are not intended to limit the scope of the invention.

In the embodiment and the comparative example of the invention, the gas product is tested by a petrochemical analysis method RIPP 77-90 method, and the coke content is determined by a petrochemical analysis method RIPP 107-90 method.

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

percent conversion: (weight of carbon tetrahydrocarbon in the feed-weight of carbon tetrahydrocarbon in the product)/(weight of carbon tetrahydrocarbon in the feed) × 100%

Yield%

Selectivity% -yield/conversion X100%

The RIPP petrochemical analysis method is selected from the editions of petrochemical analysis method (RIPP test method), Yangshui and the like, and scientific publishing house, 1990.

The examples and comparative examples used different alkane contents of the tetracarbon, the composition of which is shown in table 1.

TABLE 1

Preparation example

The oxidation state catalysts having the compositions as listed in tables 2 and 3 were prepared.

Soaking a certain amount of metal salt solution in a ZRP molecular sieve (the Si/Al molar ratio is 150), drying and roasting to obtain an active component, pulping the active component and deionized water, and uniformly stirring to obtain molecular sieve slurry;

taking a certain amount of kaolin and alumina sol, uniformly mixing, adding deionized water, pulping and uniformly stirring to obtain carrier slurry;

mixing and pulping the molecular sieve slurry and the carrier slurry, then sequentially carrying out spray drying, washing and filtering, then drying for 4h at 120 ℃, and roasting for 6h at 700 ℃ to obtain the oxidation state catalyst.

TABLE 2

Composition, by weight%	cat-1	cat-2	cat-3	cat-4
					Substrate (Kaolin)	40.0	38.0	35.0	41.0
Binder (aluminium sol)	13.5	14.9	13.8	12.3
					ZRP molecular sieve	45.0	45.0	50.0	45.0
Fe element	0.2	0.5	0.2	0.5
					Cr element	1.0	1.2	1.0	0.8
Element V	0.3	0.4	0.0	0.4

TABLE 3

Composition, by weight%	cat-5	cat-6	cat-7	cat-8
					Substrate (Kaolin)	32.0	68.0	65.0	32.0
Binder (aluminium sol)	18.0	30.1	33.3	21.5
					ZRP molecular sieve	50.0	0.0	0.0	45.0
Fe element	0.0	0.5	0.5	0.0
					Cr element	0.0	1.0	1.2	1.0
Element V	0.0	0.4	0.0	0.5

Examples 1 to 4

The reaction to produce ethylene and propylene from the tetracarbon was carried out on a pilot plant as shown in FIG. 1, according to the conditions in Table 4.

Wherein the inner diameter of the riser is 30mm, the height is 200mm, the inner diameter of the fluidized bed reactor is 80mm, and the height is 500 mm.

Feeding oxidation state catalysts cat-1 to cat-4 into a regenerator to be mixed with a spent catalyst and/or a balancing agent, wherein the spent catalyst is regenerated and then fed into a catalyst riser; meanwhile, the ethane-rich component is used as lifting gas, is introduced into the lifting pipe to lift the oxidation state catalyst and is partially reduced into the fluidized state catalyst, and then is introduced into the fluidized bed reactor to contact with the steam atomized carbon tetrahydrocarbon for catalytic reaction;

introducing the oil agent mixture obtained by the reaction into a settler, separating by a cyclone separator, and introducing the obtained agent to be regenerated into a regenerator for regeneration and recycling after steam stripping;

the obtained reaction oil gas is introduced into a separation unit for separation, so that a light hydrocarbon component, an ethylene-rich component, an ethane-rich component, a propylene-rich component and a heavy hydrocarbon component are obtained respectively, wherein the light hydrocarbon component and the ethane-rich component are introduced into a combustion device for combustion, the generated heat is introduced into a regenerator, and the heavy hydrocarbon component is returned to be mixed with the carbon-tetrahydrocarbon. The final products obtained and the reaction results are shown in Table 4.

TABLE 4

Mass ratio of catalyst to fresh carbon four hydrocarbons

Is the mass percent of the addition of the carbon four hydrocarbons

Comparative examples 1 to 2

The catalytic reaction was carried out on a pilot plant of a medium fixed bed reactor according to the conditions in table 5. The reactor had an internal diameter of 100mm and a length of 800 mm. The catalyst cat-5 is filled in a reactor, and the reactor alternately carries out catalytic reaction and catalyst regeneration.

Introducing the carbon tetrahydrocarbon and the dilution steam into the reactor together, contacting with the filled catalyst and carrying out catalytic reaction;

and introducing the product obtained by the reaction into a separation unit for separation to obtain a light hydrocarbon component, an ethylene-rich component, an ethane-rich component, a propylene-rich component and a heavy hydrocarbon component respectively. The final products, reaction conditions and results are shown in table 5.

Comparative example 3

The catalytic reaction was carried out on a pilot plant of a medium series fixed bed reactor according to the conditions in table 5. The first reactor has an inner diameter of 80mm and a length of 600mm, and is filled with a catalyst cat-7; the second reactor had an internal diameter of 100mm and a length of 800mm and was packed with the catalyst cat-8.

Comparative example 4

The catalytic reaction was carried out on a pilot plant of a medium fixed bed reactor according to the conditions in table 5. The reactor had an internal diameter of 100mm and a length of 1500 mm. The catalyst cat-7 is filled in the front half part of the reactor, and the catalyst cat-8 is filled in the rear half part of the reactor; the filling length of the catalyst cat-7 is 600mm, and the filling length of the catalyst cat-8 is 900 mm.

and introducing the product obtained by the reaction into a separation unit for separation to obtain a light hydrocarbon component, an ethylene-rich component, an ethane-rich component, a propylene-rich component and a heavy hydrocarbon component respectively. Finally, the yield and selectivity of each product are calculated. The reaction conditions and results are shown in Table 5.

TABLE 5

Mass ratio of catalyst to fresh carbon four hydrocarbons

Is the mass percent of the addition of the carbon four hydrocarbons

As can be seen from tables 4 and 5, by using the method provided by the present invention, higher yields of ethylene and propylene can be obtained by treating the C-tetrads with high alkane content.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for producing ethylene and propylene from a tetracarbon comprising:

2. The method of claim 1, wherein the mass fraction of the tetraarbons is not less than 50%.

3. The process of claim 1 or 2, wherein the molecular sieve having the MFI structure is a modified or unmodified ZSM-5 molecular sieve; preferably, the ZSM-5 molecular sieve has a Si/Al molar ratio of 100-300: 1.

4. A method according to any one of claims 1 to 3, wherein the metallic active components comprise a metal or oxide of the element Cr and optionally a metal or oxide of the element Fe and/or V; preferably, the content of Fe element is 0-5 wt%, preferably 0.2-1 wt%, the content of Cr element is 0.5-8 wt%, preferably 0.8-2 wt%, and the content of V element is 0-15 wt%, preferably 3-8 wt% of the molecular sieve.

5. The method of any one of claims 1-4, wherein the matrix is selected from at least one of kaolin, montmorillonite, and bentonite;

preferably, the binder is selected from at least one of silica sol, aluminum sol, and pseudo-boehmite.

6. The method of any one of claims 1-5, wherein the catalytic reaction comprises a catalytic cracking reaction and a catalytic dehydrogenation reaction of the tetracarbon at the same time.

7. The method of any one of claims 1-6, wherein the conditions of the catalytic reaction comprise: the temperature is 450-700 ℃, preferably 550-650 ℃; the agent-oil ratio is 2-30, preferably 5-20; the reaction time is 0.5 to 10 seconds, preferably 1 to 5 seconds; the reaction pressure is 0.1-0.6MPa, preferably 0.15-0.4 MPa; the amount of steam used is 1 to 50 wt%, preferably 5 to 30 wt%, based on the amount of the hydrocarbon tetracarbonate added.

8. The method of any of claims 1-7, wherein the method further comprises: separating the product obtained by the catalytic reaction to obtain a light hydrocarbon component, an ethylene-rich component, an ethane-rich component, a propylene-rich component and a heavy hydrocarbon component;

regenerating the catalyst and returning to the catalytic reaction;

combusting the light hydrocarbon component and the ethane-rich component to generate heat for the regeneration and the catalytic reaction;

returning the heavy hydrocarbon components to the catalytic reaction.

9. The process of claim 8, wherein the fluidized catalyst is obtained by subjecting an oxidized catalyst to lifting and reduction with a lift gas, wherein the lift gas is a light hydrocarbon component or an ethane-rich component.

10. The method as claimed in claim 9, wherein the temperature of the regeneration is 660-720 ℃, preferably 680-700 ℃; preferably, the regeneration process introduces a combustion gas, preferably selected from one or more of air, oxygen and other gases having an oxidizing effect, preferably air.