CN116376590B

CN116376590B - Methods and apparatus for the co-production of low-carbon olefins and aromatics from Fischer-Tropsch synthesis products

Info

Publication number: CN116376590B
Application number: CN202310217662.3A
Authority: CN
Inventors: 杨勇; 尹烁; 陶智超; 郝坤; 张玲; 郭艳; 王新娟; 徐智; 姜大伟; 樊莲莲; 李江; 申陈魁; 吴德宏; 师海峰; 李永旺
Original assignee: Synfuels China Inner Mongolia Co ltd; Shanxi Institute of Coal Chemistry of CAS; Zhongke Synthetic Oil Technology Co Ltd
Current assignee: Synfuels China Inner Mongolia Co ltd; Shanxi Institute of Coal Chemistry of CAS; Zhongke Synthetic Oil Technology Co Ltd
Priority date: 2023-03-03
Filing date: 2023-03-03
Publication date: 2026-02-13
Anticipated expiration: 2043-03-03
Also published as: CN116376590A

Abstract

The invention provides a method for co-producing light olefins and aromatic hydrocarbons from Fischer-Tropsch synthesis products and a device for implementing the method. According to the method, different Fischer-Tropsch synthesis products are respectively fed into three reactors connected in series, wherein the first reactor is mainly used for treating Fischer-Tropsch low-carbon saturated hydrocarbon to perform catalytic pyrolysis reaction, the second reactor is mainly used for treating Fischer-Tropsch light oil to perform catalytic pyrolysis reaction, and the third reactor is mainly used for treating Fischer-Tropsch heavy oil to perform catalytic cracking and aromatization reaction, so that the aim of co-producing low-carbon olefin and aromatic hydrocarbon with higher yield is fulfilled. In particular, the method of the invention can realize the co-production of aromatic hydrocarbon with the yield of more than 30% while obtaining the low-carbon olefin with the yield of more than 39%.

Description

Method and device for co-producing low-carbon olefin and aromatic hydrocarbon from Fischer-Tropsch synthesis product

Technical Field

The invention belongs to the field of Fischer-Tropsch synthesis product processing, relates to a Fischer-Tropsch synthesis product conversion method and a device for implementing the method, and in particular relates to a method for co-producing low-carbon olefin and aromatic hydrocarbon from a Fischer-Tropsch synthesis product and a device for implementing the method.

Background

Fischer-Tropsch synthesis is a process for synthesizing liquid fuel mainly comprising saturated straight-chain hydrocarbon by taking synthesis gas as a raw material under the condition of a catalyst and proper reaction conditions. The Fischer-Tropsch synthesis technology can obtain extremely clean Fischer-Tropsch synthetic oil due to the removal of sulfur and nitrogen pollutants in the synthetic gas purification unit, has wide synthetic gas sources, can be converted from coal, natural gas, coal bed gas, biomass and the like, and is not limited by natural petroleum reserves. And the low-carbon olefin and the aromatic hydrocarbon are chemical raw materials with high added value, so that considerable economic benefit can be brought. Therefore, the Fischer-Tropsch synthesis product is used as a raw material to prepare chemical raw materials such as low-carbon olefin and aromatic hydrocarbon, and the method can be more suitable for market change.

It can be seen from recent literature reports that the Fischer-Tropsch synthesis product is mainly processed by adopting a catalytic cracking technology, and the target product is mainly clean gasoline. Patent application CN106609154a discloses a method for producing gasoline from fischer-tropsch synthetic oil, which adopts two parallel reactors to process fischer-tropsch oil, wherein the first reactor is a riser reactor, the active components of the catalyst are zeolite molecular sieve and five-membered ring high silicon zeolite, the fischer-tropsch synthetic product with distillation range of 200-750 ℃ is processed, and the second reactor is a riser reactor, a fluidized bed reactor, a moving bed reactor and a descending reactor, and the mixed catalyst of spent catalyst and regenerated catalyst is used as aromatization catalyst to process liquefied gas and/or gasoline fraction. The Fischer-Tropsch synthesis product requires lower oil contact temperature and longer oil contact time for conversion to aromatic hydrocarbon, and the oil contact temperature and the contact time of the method are higher, so that the aromatic hydrocarbon yield is not ideal.

Patents CN105567299B, CN105567307B and CN106609151B disclose processes for producing lower olefins from fischer-tropsch synthesis products. However, these processes do not focus on how to obtain aromatics, but rather on how to co-produce lower olefins and aromatics.

In view of the prior art disclosed in the art, the treatment of the fischer-tropsch synthesis product is mainly focused on the process of producing gasoline from the fischer-tropsch synthesis product or producing light olefins from the fischer-tropsch synthesis product, but there are few reports on the process of co-producing light olefins in the process of producing aromatics from the fischer-tropsch synthesis product.

Disclosure of Invention

To solve the above problems, the present inventors have provided a process for co-producing light olefins and aromatics from a Fischer-Tropsch synthesis product, and also provided an apparatus for carrying out the process. According to the method, different Fischer-Tropsch synthesis products are respectively fed into three reactors connected in series, wherein the first reactor is mainly used for treating Fischer-Tropsch low-carbon saturated hydrocarbon to perform catalytic pyrolysis reaction, the second reactor is mainly used for treating Fischer-Tropsch light oil to perform catalytic pyrolysis reaction, and the third reactor is mainly used for treating Fischer-Tropsch heavy oil to perform catalytic cracking and aromatization reaction, so that the aim of co-producing low-carbon olefin and aromatic hydrocarbon with higher yield is fulfilled. In particular, the method of the present invention can obtain an aromatic hydrocarbon with a yield of 30% or more while obtaining a low-carbon olefin with a yield of 39% or more.

In one aspect, the invention provides a process for co-producing light olefins and aromatics from a Fischer-Tropsch synthesis product, the process comprising:

(1) Feeding a Fischer-Tropsch low carbon saturated hydrocarbon and an optional atomizing medium into a first reactor in an atomized form, contacting with a first catalyst and performing catalytic pyrolysis reaction to obtain a first reactant stream, and feeding the first reactant stream into a second reactor;

(2) Feeding Fischer-Tropsch light oil and an optional atomizing medium into a second reactor in an atomized form, mixing the Fischer-Tropsch light oil and the optional atomizing medium with the first reactant stream, contacting the mixture with a second catalyst and performing catalytic cracking reaction to obtain a second reactant stream, and feeding the second reactant stream to a third reactor;

(3) Feeding Fischer-Tropsch heavy oil and an optional atomizing medium into a third reactor in an atomized form, mixing the Fischer-Tropsch heavy oil and the optional atomizing medium with the second reactant stream, contacting the mixture with a third catalyst, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream;

(4) The method comprises the steps of (1) carrying out sedimentation separation on a third reaction stream obtained in the step (3) to remove a catalyst to be regenerated from the third reaction stream, fractionating the obtained reaction product to obtain a gas-phase product, light oil and heavy oil, carrying out olefin separation on the gas-phase product to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, carrying out aromatic extraction on the light oil to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil, carrying out steam stripping on the catalyst to be regenerated, optionally burning and regenerating to obtain a regenerated catalyst, and recycling the regenerated catalyst to the first reactor, the second reactor and the third reactor respectively.

In some embodiments, the process further comprises returning the lower saturated hydrocarbons and aromatic raffinate oil obtained in step (4) to the first reactor and the second reactor, respectively, for reprocessing. In some embodiments, the process further comprises returning the lower saturated hydrocarbons obtained in step (4) to the first reactor for reprocessing, and returning the aromatic raffinate oil obtained in step (4) to the second reactor for reprocessing.

In another aspect, the present invention provides a co-production plant for carrying out the above process, i.e. for co-production of light olefins and aromatics from Fischer Tropsch synthesis products, said plant comprising a reaction system, a regeneration system and a product separation system,

Wherein, the reaction system includes:

A first reactor;

a second reactor disposed in series with the first reactor;

a third reactor disposed in series with the second reactor;

A settling unit connected in fluid communication to the third reactor and the product separation system;

wherein the regeneration system is for catalyst regeneration and the regeneration system comprises:

A stripping section connected in fluid communication to the settling unit, and

A regenerator coupled in fluid communication to the stripping section and the first, second and third reactors.

In some embodiments, the product separation system comprises:

(a) A fractionation unit, which is used for fractionating the crude oil,

(B) An olefin separation unit, and

(C) An aromatic hydrocarbon extraction unit,

Wherein the fractionation unit is connected in fluid communication to the settling unit, and the olefin separation unit and the aromatic extraction unit are each connected in fluid communication to the fractionation unit.

In a preferred embodiment, the regeneration system further comprises:

a burn pot connected in fluid communication to the stripping section and the regenerator.

In some embodiments, a burner is also provided in the regeneration system, the burner being connected in fluid communication to the burn pot to provide oxygen-containing high temperature flue gas into the burn pot.

The method of the invention has the following beneficial effects:

(1) The method can obtain the low-carbon olefin with the yield of more than 39 percent (for example, 39% -55 percent) and obtain the aromatic hydrocarbon with the yield of more than 30 percent (for example, 30% -38 percent).

(2) The invention respectively sends Fischer-Tropsch low-carbon saturated hydrocarbon, fischer-Tropsch light oil and Fischer-Tropsch heavy oil into a first reactor, a second reactor and a third reactor. The Fischer-Tropsch low-carbon saturated hydrocarbon is subjected to catalytic pyrolysis reaction by contacting with a catalyst at a higher temperature, the Fischer-Tropsch light oil is subjected to catalytic pyrolysis reaction by contacting with a catalyst at a higher temperature, and the Fischer-Tropsch heavy oil is subjected to catalytic cracking and aromatization reaction by contacting with a catalyst at a lower temperature. The aim of co-producing the low-carbon olefin and the aromatic hydrocarbon can be better realized by flexibly adjusting the feed raw material proportion of the three reactors.

(3) The invention can increase the secondary reaction (such as superposition cyclization dehydrogenation reaction, etc.) of the olefin which is the intermediate product of the Fischer-Tropsch synthesis product catalytic cracking, and is beneficial to obtaining more aromatic hydrocarbon. Therefore, according to the different properties of Fischer-Tropsch synthesis products, three reactors are utilized to treat the Fischer-Tropsch synthesis products respectively, so that the co-production of the low-carbon olefin and the aromatic hydrocarbon is realized.

(4) The prior art has disclosed methods for the separate production of aromatics and the separate production of lower olefins from fischer-tropsch synthesis products. The invention adopts different processing modes for raw materials with different carbon numbers. The shorter the carbon number, the higher the contact temperature of the raw material with the catalyst, and the longer the carbon number, the lower the contact temperature of the raw material with the catalyst. The simultaneous production of lower olefins and aromatics can be achieved by processing a variety of feedstocks, thereby enabling good economic benefits to be realized.

Drawings

Fig. 1 is a schematic diagram of an exemplary apparatus for co-producing light olefins and aromatics from a fischer-tropsch synthesis product according to the invention.

The description of the reference numerals is as follows:

1, a first reactor, 2, a second reactor, 3, a third reactor, 4, a combustion furnace, 5, a coke burning tank, 6, a regenerator, 7, a reactor settler, 8, a regenerator settler, 9, a spent pipe, 10, a stripping section, 11, a regeneration pipe I, 12, a regeneration pipe II, 13, a regeneration pipe III, 14, a fractionation unit, 15, an olefin separation unit, 16, and an aromatic extraction unit.

The method comprises the following steps of (1) Fischer-Tropsch low-carbon saturated hydrocarbon, (II) Fischer-Tropsch light oil, (III) Fischer-Tropsch heavy oil, (IV) atomizing medium, (V) stripping steam, (VI) flue gas, (VII) gas-phase product, (VIII) light oil, (IX, heavy oil, (X) dry gas, (XI) low-carbon saturated hydrocarbon, (XII) low-carbon olefin, (XIII) aromatic hydrocarbon, (XIIV) aromatic hydrocarbon, and (XIV) aromatic hydrocarbon raffinate oil.

Detailed Description

For a better understanding of the present invention, reference is made to the following description of specific embodiments, which should not be construed as limiting the invention in any way.

In the present invention, unless otherwise indicated, the term "lower olefins" refers to C2-C4 olefins, including, for example, ethylene, propylene, 1-butene, isobutylene, cis-2-butene, trans-2-butene, or mixtures thereof.

In the present invention, unless otherwise indicated, the term "aromatic hydrocarbon" refers to C6-C10 aromatic hydrocarbons, including benzene, toluene, ethylbenzene, ortho-xylene, meta-xylene, para-xylene, and C9, C10 aromatic hydrocarbons or mixtures thereof.

In the present invention, unless otherwise indicated, the term "lower saturated hydrocarbon" refers to a C2-C4 alkane, including, for example, ethane, propane, butane, isobutane, or mixtures thereof.

In the present invention, unless otherwise indicated, the term "gas phase product" refers to a fraction of the product having a distillation range below 15 ℃.

In the present invention, the term "light oil" refers to a fraction in the product having a distillation range of 15 to 220 ℃, unless otherwise indicated.

In the present invention, the term "heavy oil" refers to a fraction in the product having a distillation range of 220 ℃ or more, unless otherwise specified.

In the present invention, unless otherwise indicated, the term "dry gas" means the fraction remaining after separation of "olefins (i.e., lower olefins)" and lower saturated hydrocarbons in "gas phase product". For example, the dry gas may include hydrogen, methane, or mixtures thereof.

In the present invention, unless otherwise indicated, the term "aromatic raffinate" refers to the portion of the "light oil" that remains after separation of the "aromatic" from the "light oil".

In the present invention, the term "spent catalyst" refers to a carbon-containing catalyst in which the catalyst has undergone a reaction, unless otherwise specified. For example, the term "spent catalyst" may refer to a carbon-containing catalyst that undergoes a reaction to a vapor advance. In some cases, the term "spent catalyst" includes carbonaceous catalysts obtained by reacting and stripping the catalyst, commonly referred to as stripped spent catalyst.

In the present invention, unless otherwise indicated, the term "carbon deposit" refers to the characterization of the carbon content of a spent catalyst using a sulfur carbon analyzer or a thermogravimetric analyzer, in combination with the calculation of the total carbon content of the spent catalyst.

In the step (1), the Fischer-Tropsch low carbon saturated hydrocarbon is C2-C4 alkane obtained by olefin separation of Fischer-Tropsch liquefied gas, and specifically may comprise ethane, propane, butane, isobutane or a mixture thereof. Wherein the Fischer-Tropsch liquefied gas may be a C2-C4 hydrocarbon in a Fischer-Tropsch synthesis product. For example, the Fischer-Tropsch liquefied gas may comprise ethane, ethylene, propane, propylene, n-butane, isobutane, cis-2-butene, trans-2-butene, or a mixture thereof.

In step (2), the Fischer-Tropsch light oil is selected from Fischer-Tropsch synthesized light components with initial distillation points ranging from 36 ℃ to 220 ℃, but is not limited to the Fischer-Tropsch light components. In some embodiments, the Fischer-Tropsch light oil comprises predominantly C5-C12 hydrocarbons in Fischer-Tropsch synthesis products.

In step (3), the Fischer-Tropsch heavy oil is a Fischer-Tropsch heavy fraction having an initial boiling point of greater than 220 ℃, preferably greater than 280 ℃. In some embodiments, the Fischer-Tropsch heavy oil comprises predominantly hydrocarbons above C12 in the Fischer-Tropsch synthesis product.

In the invention, the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon, the Fischer-Tropsch light oil and the Fischer-Tropsch heavy oil can be (5-30): (5-40): (30-90).

In a preferred embodiment, in step (1), step (2) or step (3), the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil or Fischer-Tropsch heavy oil is mixed with the optional atomising medium for atomisation. Wherein the atomizing medium may be selected from one or more of methanol, ethanol, propanol, dry gas, nitrogen or water vapor, for example mixtures thereof. The dry gas comprises one or more of hydrogen, methane and ethane. In some embodiments, the dry gas may be hydrogen, methane, ethane in a fischer-tropsch product. In the present invention, atomization may be carried out according to the procedures available in the art.

In particular embodiments, the mass ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the atomizing medium may be 1 (0-1), preferably 1 (0.1-1), such as ,1:0、1:0.1、1:0.15、1:0.18、1:0.2、1:0.25、1:0.3、1:0.35、1:0.4、1:0.45、1:0.5、1:0.55、1:0.6、1:0.65、1:0.7、1:0.75、1:0.8、1:0.85、1:0.9、1:0.95 or 1:1, or the mass ratio of the Fischer-Tropsch light oil to the atomizing medium may be 1 (0-1), preferably 1 (0.1-1), such as ,1:0、1:0.1、1:0.15、1:0.18、1:0.2、1:0.25、1:0.3、1:0.35、1:0.4、1:0.45、1:0.5、1:0.55、1:0.6、1:0.65、1:0.7、1:0.75、1:0.8、1:0.85、1:0.9、1:0.95 or 1:1, or the mass ratio of the Fischer-Tropsch heavy oil to the atomizing medium may be 1 (0-1), preferably 1 (0.1-1), such as ,1:0、1:0.1、1:0.15、1:0.18、1:0.2、1:0.25、1:0.3、1:0.35、1:0.4、1:0.45、1:0.5、1:0.55、1:0.6、1:0.65、1:0.7、1:0.75、1:0.8、1:0.85、1:0.9、1:0.95 or 1:1.

Preferably, in step (1), the weight ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the atomising medium is from 1 (0 to 0.6), preferably from 1 (0.15 to 0.6). Preferably, in step (2), the weight ratio of Fischer-Tropsch light oil to the atomizing medium is 1 (0-0.8), preferably 1 (0.15-0.5). Preferably, in step (3), the weight ratio of the Fischer-Tropsch heavy oil to the atomising medium is from 1 (0 to 0.8), preferably from 1 (0.15 to 0.5).

In some preferred embodiments, in step (1), step (2) or step (3), the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil or Fischer-Tropsch heavy oil is preheated before atomization. Preferably, the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil or Fischer-Tropsch heavy oil is preheated to a temperature of 100-400 ℃. More preferably, in step (1), the Fischer-Tropsch low carbon saturated hydrocarbon is preheated to a temperature of from 100 ℃ to 350 ℃. Preferably, in step (2), the Fischer-Tropsch light oil is preheated to a temperature of from 100 ℃ to 350 ℃. In step (3), the Fischer-Tropsch heavy oil is preheated to a temperature of from 100 ℃ to 350 ℃.

In some preferred embodiments, the active component of the first, second and third catalysts of the present invention is at least one selected from the group consisting of an unmodified or modified eight-membered ring molecular sieve, a ten-membered ring molecular sieve, a twelve-membered ring molecular sieve, or a metal oxide. Preferably, the eight-membered ring molecular sieve, the ten-membered ring molecular sieve or the twelve-membered ring molecular sieve can be selected from SAPO-34, SAPO-18, ITQ-13, IM-5, ZSM-11, MCM-22, EU-1, beta, mordenite molecular sieve and the like, and the metal oxide can be selected from one or more of zinc oxide, lanthanum oxide, magnesium oxide, manganese oxide, cerium oxide, gallium oxide, chromium oxide, nickel oxide and tungsten oxide.

In some preferred embodiments, the active components of the first, second and third catalysts comprise 20wt% to 60wt% of the catalyst weight on a dry basis. In addition, it is preferable that the first catalyst, the second catalyst, and the third catalyst contain, in addition to the active component, the remaining amount of alumina and/or silica as a carrier.

In some preferred embodiments, the first catalyst may be a mixed catalyst of regenerated catalyst and spent catalyst, wherein the carbon content of the first catalyst may be 0wt% to 2.00wt%. In another further preferred embodiment, the second catalyst may be a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the second catalyst may be 0wt% to 2.0wt%. In another further preferred embodiment, the third catalyst may be a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the third catalyst may be 0wt% to 2.0wt%.

In some preferred embodiments, in step (1), the reaction conditions of the first reactor are a temperature of 500 ℃ to 750 ℃, preferably 580 ℃ to 680 ℃, a pressure of 0.01 to 0.7MPa, preferably 0.1 to 0.5MPa, a weight hourly space velocity of 10 to 300h ^-1, preferably 40 to 200h ^-1, and a catalyst to oil ratio of 0.5 to 50, preferably 5 to 30.

In some preferred embodiments, in step (2), the reaction conditions of the second reactor are a temperature of 450 ℃ to 700 ℃, preferably 530 ℃ to 630 ℃, a pressure of 0.01 to 0.7MPa, preferably 0.1 to 0.5MPa, a weight hourly space velocity of 1 to 150h ^-1, preferably 40 to 120h ^-1, a catalyst to oil ratio of 1 to 40, preferably 5 to 25.

In some preferred embodiments, in step (3), the reaction conditions of the third reactor are a temperature of 400 ℃ to 650 ℃, preferably 480 ℃ to 580 ℃, a pressure of 0.01 to 0.7MPa, preferably 0.1 to 0.5MPa, a weight hourly space velocity of 0.5 to 30h ^-1, preferably 2 to 20h ^-1, and a catalyst to oil ratio of 1 to 20, preferably 2 to 15.

In some preferred embodiments, the first reactor is a transport bed reactor, a fast bed reactor or a turbulent bed reactor, preferably a transport bed reactor and a fast bed reactor. Wherein, the raw materials with shorter carbon chains can be contacted with the catalyst at higher temperature to generate catalytic thermal cracking reaction, thereby obtaining more olefin.

In some preferred embodiments, the second reactor is a rapid bed reactor, a turbulent bed reactor or a bubbling bed reactor, preferably a turbulent bed reactor or a rapid bed reactor. Wherein, the raw materials with moderate carbon chains can be contacted with the catalyst at a higher temperature to generate catalytic cracking reaction, thereby obtaining more olefins.

In some preferred embodiments, the third reactor is a turbulent, bubbling or bulk fluidized bed reactor, preferably a turbulent or bubbling bed reactor. Wherein, the raw materials with longer carbon chains can be contacted with the catalyst at a lower temperature and more catalytic cracking reaction, superposition reaction, cyclization reaction, hydrogen transfer reaction and aromatization reaction can occur under the condition of lower space velocity, thereby obtaining more aromatic hydrocarbons.

In some preferred embodiments, in step (4), the settling separation is operated at a pressure of 0.01 to 0.7MPa, preferably 0.1 to 0.5MPa.

In this context, fractionation, olefin separation, aromatic extraction and stripping are all carried out using procedures conventional in the art, without any particular limitation.

In some preferred embodiments, 10-90% of the low carbon saturated hydrocarbons obtained in step (4) may be returned to the first reactor for reprocessing, and 5-95% of the aromatic raffinate oil obtained in step (4) may be returned to the second reactor for reprocessing.

In some preferred embodiments, in step (4), the optional charring and regeneration of the spent catalyst is performed by contacting the spent catalyst with an oxygen-containing gas at a pressure of 0.01 to 0.7MPa, preferably 0.1 to 0.5MPa, and at a temperature of 550 to 750 ℃, preferably 580 to 700 ℃. Preferably, the oxygen-containing gas may be air or oxygen-containing high temperature flue gas.

In a further aspect, the present invention provides a co-production plant for carrying out the above process, i.e. a plant for co-production of light olefins and aromatics from a Fischer Tropsch synthesis product, the plant comprising a reaction system, a regeneration system and a product separation system,

Wherein, the reaction system includes:

A first reactor;

a second reactor disposed in series with the first reactor;

a third reactor disposed in series with the second reactor;

Wherein the regeneration system comprises:

a stripping section connected in fluid communication to the settling unit;

In a preferred embodiment, the regeneration system further comprises:

In some embodiments, a burner is also provided in the regeneration system, the burner being connected in fluid communication to the burn pot to provide oxygen-containing high temperature flue gas (e.g., at a flue gas temperature of 550-750 ℃) into the burn pot.

In some embodiments, fuel gas and air are fed into a combustion furnace to be ignited, generating oxygen-containing high temperature flue gas, which is then passed into a char tank. In some embodiments, the fuel gas may be selected from liquefied petroleum gas, alkanes having a composition of C3, C4.

In some embodiments, the product separation system comprises:

a fractionation unit connected in fluid communication to the settling unit;

an olefin separation unit connected in fluid communication to the fractionation unit, and

An aromatic extraction unit connected in fluid communication to the fractionation unit.

In some preferred embodiments, the first reactor is a transport bed reactor, a fast bed reactor or a turbulent bed reactor, preferably a transport bed reactor or a fast bed reactor.

In some preferred embodiments, the second reactor is a rapid bed reactor, a turbulent bed reactor, or a bubbling bed reactor. In the present invention, the second reactor is preferably a rapid bed reactor or a turbulent bed reactor.

In some preferred embodiments, the third reactor is a turbulent, bubbling or bulk fluidized bed reactor, preferably a turbulent or bubbling bed reactor.

In this context, the first, second and third reactors may share one settler.

The method provided by the invention is further described below with reference to the accompanying drawings.

The Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 100-400 ℃ and an optional atomization medium are mixed and atomized according to the mass ratio of 1 (0-1), and then are fed into a first reactor, and are contacted with a first catalyst and subjected to catalytic pyrolysis reaction under the conditions of the reaction temperature of 500-750 ℃, the reaction pressure of 0.01-0.7MPa, the catalyst-oil ratio of 0.5-50 and the weight hourly space velocity of 10-300h ^-1, so that a first reactant flow is obtained. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

The Fischer-Tropsch light oil preheated to 100-400 ℃ and an optional atomization medium are mixed and atomized according to the mass ratio of 1 (0-1), and then are fed into a second reactor, the Fischer-Tropsch light oil enters the second reactor and is mixed with a first reactant flow, and the mixture is contacted with a second catalyst for catalytic cracking reaction under the conditions that the reaction temperature is 450-700 ℃, the reaction pressure is 0.01-0.7MPa, the catalyst-oil ratio is 1-40 and the weight hourly space velocity is 1-150h ^-1, so that a second reactant flow is obtained. The second reactant stream carrying the reacted second catalyst is sent to a third reactor.

The Fischer-Tropsch heavy oil preheated to 100-400 ℃ and an optional atomization medium are mixed and atomized according to the mass ratio of 1 (0-1), and then are fed into a third reactor, the Fischer-Tropsch heavy oil enters the third reactor and is mixed with a second reactant flow, and the Fischer-Tropsch heavy oil is contacted with the third catalyst and undergoes catalytic cracking and aromatization reactions under the conditions of the reaction temperature of 400-650 ℃, the reaction pressure of 0.01-0.7MPa, the catalyst-oil ratio of 1-20 and the weight hourly space velocity of 0.5-30h ^-1, so that the third reactant flow is obtained.

And carrying the third catalyst after the reaction by the third reaction flow upwards, and carrying out sedimentation separation in a sedimentation device under the operating pressure of 0.01-0.7MPa to obtain a reaction product and a catalyst to be regenerated. And fractionating the reaction product in a fractionating unit to obtain a gas-phase product, light oil and heavy oil, wherein the gas-phase product enters an olefin separation unit to carry out olefin separation to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic extraction unit to carry out aromatic extraction to obtain aromatic hydrocarbon and aromatic raffinate oil. In some preferred embodiments, 10-90% of the resulting lower saturated hydrocarbons and 5-95% of the aromatic raffinate oil may be returned to the first reactor and the second reactor, respectively, for recycle.

Steam stripping is carried out on the catalyst to be regenerated, the catalyst to be regenerated is sent into an optional burning tank and a regenerator through a pipe to be regenerated for optional burning and regeneration, the catalyst to be regenerated is contacted with oxygen-containing gas (such as air) at the temperature of 550-750 ℃ and the pressure of 0.1-0.7MPa, carbon deposition is burnt out, the regenerated catalyst is obtained, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor through a regeneration pipe I, a regeneration pipe II and a regeneration pipe III for recycling.

Exemplary embodiments of the present invention may be described in the following numbered paragraphs, but the scope of the present invention is not limited thereto:

1. A process for co-producing light olefins and aromatics from a fischer-tropsch synthesis product, the process comprising:

2. The process of paragraph 1, wherein the process further comprises returning the lower saturated hydrocarbons and aromatic raffinate oil obtained in step (4) to the first reactor and the second reactor, respectively, for reprocessing.

3. The method of paragraph 1 wherein the mass ratio of Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil to Fischer-Tropsch heavy oil is (5-30): 5-40): 30-90.

4. A method according to any of paragraphs 1-3, wherein in step (1), step (2) or step (3) the atomising medium is selected from methanol, ethanol, propanol, dry gas, nitrogen or water vapour, or a mixture thereof.

5. The method of paragraph 4, wherein the dry gas comprises one or more of hydrogen, methane, and ethane.

6. The method of paragraph 4 wherein the dry gas is hydrogen, methane, ethane in a Fischer Tropsch product.

7. The method of any of paragraphs 1-3, wherein in step (1), step (2) or step (3), the mass ratio of the Fischer-Tropsch low carbon saturated hydrocarbon, the Fischer-Tropsch light oil or the Fischer-Tropsch heavy oil to the atomizing medium is 1 (0-1).

8. The method of paragraph 7, wherein in step (1), step (2) or step (3), the mass ratio of the Fischer-Tropsch low carbon saturated hydrocarbon, the Fischer-Tropsch light oil or the Fischer-Tropsch heavy oil to the atomizing medium is 1 (0.1-1).

9. The method of paragraph 7, wherein in step (1), step (2) or step (3), the mass ratio of the Fischer-Tropsch low carbon saturated hydrocarbon, the Fischer-Tropsch light oil or the Fischer-Tropsch heavy oil to the atomizing medium is 1:0、1:0.1、1:0.15、1:0.18、1:0.2、1:0.25、1:0.3、1:0.35、1:0.4、1:0.45、1:0.5、1:0.55、1:0.6、1:0.65、1:0.7、1:0.75、1:0.8、1:0.85、1:0.9、1:0.95 or 1:1.

10. The method of any of paragraphs 1-3, wherein in step (1) the weight ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the nebulized medium is from 1 (0-0.6), or wherein in step (2) the weight ratio of the Fischer-Tropsch light oil to the nebulized medium is from 1 (0-0.8), or wherein in step (3) the weight ratio of the Fischer-Tropsch heavy oil to the nebulized medium is from 1 (0-0.8).

11. The method of paragraph 10, wherein in step (1) the weight ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the atomizing medium is from 1 (0.15 to 0.6), or wherein in step (2) the weight ratio of the Fischer-Tropsch light oil to the atomizing medium is from 1 (0.15 to 0.5), or wherein in step (3) the weight ratio of the Fischer-Tropsch heavy oil to the atomizing medium is from 1 (0.15 to 0.5).

12. A method as claimed in any one of paragraphs 1 to 3, wherein in step (1), step (2) or step (3) the fischer-tropsch low carbon saturated hydrocarbon, fischer-tropsch light oil or fischer-tropsch heavy oil is preheated before atomisation is carried out.

13. The method of paragraph 12, wherein the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil or Fischer-Tropsch heavy oil is preheated to 100-400 ℃.

14. The method of paragraph 13, wherein the Fischer-Tropsch low carbon saturated hydrocarbon is preheated to 100-350 ℃, or wherein the Fischer-Tropsch light oil is preheated to 100-350 ℃, or wherein the Fischer-Tropsch heavy oil is preheated to 100-350 ℃.

15. The method according to any one of paragraphs 1-3, wherein the active components of the first, second and third catalysts are at least one selected from the group consisting of unmodified or modified eight-membered ring molecular sieves, ten-membered ring molecular sieves, twelve-membered ring molecular sieves, or metal oxides.

16. The method of paragraph 15 wherein the eight-membered, ten-membered or twelve-membered ring molecular sieve is selected from SAPO-34, SAPO-18, ITQ-13, IM-5, ZSM-11, MCM-22, EU-1, beta, mordenite molecular sieve, or the metal oxide is selected from one or more of zinc oxide, lanthanum oxide, magnesium oxide, manganese oxide, cerium oxide, gallium oxide, chromium oxide, nickel oxide, tungsten oxide.

17. The method of paragraph 15, wherein the active components of the first, second and third catalysts comprise 20wt% to 60wt% of the catalyst weight on a dry basis.

18. The method of paragraph 17, wherein the first catalyst, the second catalyst, and the third catalyst contain, in addition to the active component, alumina and/or silica as a carrier in the remaining amount.

19. The method of any of paragraphs 1-3, wherein the first catalyst is a mixed catalyst of regenerated catalyst and spent catalyst, wherein the carbon content of the first catalyst is from 0wt% to 2.00wt%, or wherein the second catalyst is a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the second catalyst is from 0wt% to 2.0wt%, or wherein the third catalyst is a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the third catalyst is from 0wt% to 2.0wt%.

20. The process according to any one of paragraphs 1-3, wherein in step (1) the reaction conditions of the first reactor are a temperature of 500-750 ℃, a pressure of 0.01-0.7MPa, a weight hourly space velocity of 10-300h ^-1, and a catalyst to oil ratio of 0.5-50.

21. The method of paragraph 20, wherein the temperature is 580 ℃ to 680 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 40 to 200h ^-1, or the catalyst to oil ratio is 5 to 30.

22. The process according to any one of paragraphs 1-3, wherein in step (2) the reaction conditions of the second reactor are a temperature of 450-700 ℃, a pressure of 0.01-0.7MPa, a weight hourly space velocity of 1-150h ^-1, and a catalyst to oil ratio of 1-40.

23. The method of paragraph 22, wherein the temperature is 530 ℃ to 630 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 40 to 120h ^-1, or the agent to oil ratio is 5 to 25.

24. The process according to any one of paragraphs 1-3, wherein in step (3) the reaction conditions of the third reactor are a temperature of 400-650 ℃, a pressure of 0.01-0.7MPa, a weight hourly space velocity of 0.5-30h ^-1, and a catalyst to oil ratio of 1-20.

25. The method of paragraph 24, wherein the temperature is 480 ℃ to 580 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 2 to 20h ^-1, or the catalyst to oil ratio is 2 to 15.

26. The method of any of paragraphs 1-3, wherein the first reactor is a transport bed reactor, a fast bed reactor, or a turbulent bed reactor, or the second reactor is a fast bed reactor, a turbulent bed reactor, or a bubbling bed reactor, or the third reactor is a turbulent bed reactor, a bubbling bed reactor, or a bulk fluidized bed reactor.

27. The method of paragraph 26, wherein the first reactor is a transport bed reactor or a fast bed reactor, or the second reactor is a fast bed reactor or a turbulent bed reactor, or the third reactor is a bubbling bed reactor or a turbulent bed reactor.

28. A process as claimed in any one of paragraphs 1-3, wherein in step (4) the settling separation is operated at a pressure of 0.01-0.7MPa.

29. The method of paragraph 2, wherein 10% -90% of the low carbon saturated hydrocarbons obtained in step (4) are returned to the first reactor for reprocessing, or 5% -95% of the aromatic raffinate oil obtained in step (4) is returned to the second reactor for reprocessing.

30. A process as claimed in any one of paragraphs 1 to 3 wherein in step (4) the spent catalyst is contacted with an oxygen-containing gas under conditions such that the optional scorch is applied and the regeneration is carried out at a pressure of from 0.01 to 0.7MPa and a temperature of from 550 ℃ to 750 ℃.

31. The method of paragraph 29, wherein the oxygen-containing gas is air or oxygen-containing high temperature flue gas.

32. An apparatus for co-producing light olefins and aromatics from a Fischer-Tropsch synthesis product, the apparatus comprising a reaction system, a regeneration system and a product separation system,

Wherein, the reaction system includes:

A first reactor;

a second reactor disposed in series with the first reactor;

a third reactor disposed in series with the second reactor;

Wherein the regeneration system comprises:

a stripping section connected in fluid communication to the settling unit;

A regenerator connected in fluid communication to the stripping section and the first, second and third reactors,

Wherein the product separation system comprises:

a fractionation unit connected in fluid communication to the settling unit;

33. The apparatus of paragraph 32, wherein the regeneration system further comprises:

34. The apparatus of paragraph 33, wherein a burner is also provided in the regeneration system, the burner being connected in fluid communication to the burn pot to provide oxygen-containing high temperature flue gas into the burn pot.

35. The apparatus of any of paragraphs 32-34, wherein the first reactor, second reactor and third reactor share a single settler.

Examples

The reagents, materials, and apparatus involved in the following examples are commercially available as is conventional in the art, unless otherwise indicated, and conventional procedures involved in the following examples can be found in patents, patent applications, publications, and the like, which are published in the art (e.g., he Yongde, main edition, handbook of modern coal chemical industry, chemical industry Press, 2003, the entire contents of which are incorporated herein by reference).

The relevant properties of the Fischer-Tropsch heavy oil, fischer-Tropsch light oil, fischer-Tropsch low carbon saturated hydrocarbon and dry gas used in the examples below are shown in tables 1,2 and 3.

TABLE 1 relevant Properties of Fischer-Tropsch products

Note that the chromatographic limit of detection is 79% at 720 ℃ and that the chromatographic limit of detection is exceeded

TABLE 2 Fischer-Tropsch Low carbon saturated hydrocarbon composition

	Content by weight percent
		Ethane (ethane)	5%
Propane	40%
		Butane	21%
Isobutane	34%

TABLE 3 composition of dry gas

	Content by weight percent
		Hydrogen gas	36%
Methane	64%

Table 4 molecular sieves, modifying element types and content, composition, specific surface area, and pore volume of catalysts

Example 1

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 10:10:80, and the catalyst is the cat-1 catalyst.

Mixing the Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 250 ℃ with methanol, atomizing the mixture by the methanol, feeding the mixture into a first conveying bed reactor, enabling the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the methanol to be 1:0.25, enabling the mixture to contact with a first catalyst under the conditions that the reaction temperature is 660 ℃, the catalyst-oil ratio of the first catalyst in the first reactor and the Fischer-Tropsch low-carbon saturated hydrocarbon is 10, and the weight hourly space velocity is 60h ^-1, and enabling the mixture to undergo catalytic thermal cracking reaction, thus obtaining a first reactant flow. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

Mixing Fischer-Tropsch light oil and methanol preheated to 200 ℃ and sending the mixture into a second rapid bed reactor by utilizing methanol atomization, wherein the mass ratio of the Fischer-Tropsch light oil to the methanol is 1:0.25, the Fischer-Tropsch light oil is mixed with a first reactant flow after entering the second reactor, and the mixture is contacted with the second catalyst for catalytic cracking reaction under the conditions that the reaction temperature is 560 ℃ and the catalyst-oil ratio of the second catalyst to the Fischer-Tropsch light oil is 8 and the weight hourly space velocity is 50h ^-1, so that a second reactant flow is obtained. The second reactant stream carries the reacted second catalyst to the third reactor.

Mixing Fischer-Tropsch heavy oil preheated to 150 ℃ with methanol, atomizing the mixture by the methanol, sending the mixture into a third turbulent bed reactor, wherein the mass ratio of the Fischer-Tropsch heavy oil to the methanol is 1:0.25, mixing the Fischer-Tropsch heavy oil with a second reactant stream after the Fischer-Tropsch heavy oil enters the third reactor, contacting the Fischer-Tropsch heavy oil with the third catalyst under the conditions that the reaction temperature is 470 ℃, the catalyst-oil ratio of the third catalyst of the third reactor to the Fischer-Tropsch heavy oil is 2.2 and the weight hourly space velocity is 4h ^-1, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.3MPa, the reaction product enters a fractionation unit to obtain a gas phase product, light oil and heavy oil, wherein the gas phase product passes through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 10% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 5% of the aromatic raffinate oil is returned to the second reactor for recycling.

The fuel gas and air enter a combustion furnace to be ignited to generate oxygen-containing high-temperature flue gas, and then the oxygen-containing high-temperature flue gas enters a coke burning tank.

Steam stripping the spent catalyst in the stripping section, feeding the spent catalyst into a burning tank through a spent pipe, contacting with oxygen-containing high-temperature flue gas from a combustion furnace to burn, and feeding the spent catalyst to a regenerator to thoroughly burn off carbon deposit. The temperature of the burning and the regeneration is 630 ℃ and the pressure is 0.3MPa, so as to obtain the regenerated catalyst, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor for recycling through the regeneration pipe I, the regeneration pipe II and the regeneration pipe III. And calculating to obtain the carbon deposition by measuring the carbon content in the catalyst to be regenerated.

Comparative example 1

The reaction conditions of this comparative example were the same as those in the first reactor of example 1 except that the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil and Fischer-Tropsch heavy oil were all mixed and fed into the first reactor, the second reactor was used only for lifting the catalyst, and the third reactor was used only for recycling the catalyst. As shown in comparative example 1, fischer-Tropsch low-carbon saturated hydrocarbon, fischer-Tropsch light oil and Fischer-Tropsch heavy oil all enter a first reactor to react, so that more olefin is obtained, but the yield of aromatic hydrocarbon is lower.

Comparative example 2

The reaction conditions of this comparative example were the same as those in the third reactor of example 1 except that the Fischer-Tropsch low carbon saturated hydrocarbon, fischer-Tropsch light oil and Fischer-Tropsch heavy oil were all fed into the third reactor after being mixed, and the first reactor and the second reactor were used only for lifting the catalyst. As shown in comparative example 2, fischer-Tropsch low-carbon saturated hydrocarbon, fischer-Tropsch light oil and Fischer-Tropsch heavy oil all enter a third reactor to react, more liquid-phase products are generated, and the yields of low-carbon olefin and aromatic hydrocarbon are lower.

Example 2

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 5:15:80, and the catalyst is the cat-2 catalyst.

Mixing the Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 280 ℃ with methanol, atomizing the mixture by the methanol, feeding the mixture into a first rapid bed reactor, enabling the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the methanol to be 1:0.25, enabling the mixture to contact with a first catalyst under the conditions that the reaction temperature is 610 ℃, the catalyst-oil ratio of the first catalyst in the first reactor and the Fischer-Tropsch low-carbon saturated hydrocarbon is 15, and the weight hourly space velocity is 45h ^-1, and enabling the mixture to undergo catalytic pyrolysis reaction, thus obtaining a first reactant stream. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

Mixing Fischer-Tropsch light oil and methanol preheated to 250 ℃ and sending the mixture into a second turbulent bed reactor by utilizing methanol atomization, wherein the mass ratio of the Fischer-Tropsch light oil to the methanol is 1:0.25, mixing the Fischer-Tropsch light oil with a first reactant flow after entering the second reactor, and contacting the Fischer-Tropsch light oil with the second catalyst under the conditions that the reaction temperature is 560 ℃ and the catalyst-oil ratio of the second catalyst to the Fischer-Tropsch light oil is 10 and the weight hourly space velocity is 60h ^-1 to generate catalytic cracking reaction to obtain a second reactant flow. The second reactant stream carries the reacted second catalyst and is lifted to the third reactor via a riser.

Mixing Fischer-Tropsch heavy oil preheated to 180 ℃ with methanol, atomizing the mixture by the methanol, sending the mixture into a third bubbling bed reactor, wherein the mass ratio of the Fischer-Tropsch heavy oil to the methanol is 1:0.25, mixing the Fischer-Tropsch heavy oil with a second reactant stream after the Fischer-Tropsch heavy oil enters the third reactor, contacting the mixture with the third catalyst under the conditions that the reaction temperature is 490 ℃, the catalyst-oil ratio of the third catalyst of the third reactor to the Fischer-Tropsch heavy oil is 3.5 and the weight hourly space velocity is 4h ^-1, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.5MPa, the reaction product is fractionated to obtain gas phase products, light oil and heavy oil, wherein the gas phase products pass through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 20% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 15% of the aromatic raffinate oil is returned to the second reactor for recycling.

Steam stripping the spent catalyst in the stripping section, feeding the spent catalyst into a burning tank through a spent pipe, contacting with oxygen-containing high-temperature flue gas from a combustion furnace to burn, and feeding the spent catalyst to a regenerator to thoroughly burn off carbon deposit. The temperature of the burning and the regeneration is 580 ℃ and the pressure is 0.5MPa, so as to obtain the regenerated catalyst, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor for recycling through the regeneration pipe I, the regeneration pipe II and the regeneration pipe III. And calculating to obtain the carbon deposition by measuring the carbon content in the catalyst to be regenerated.

Example 3

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 5:5:90, and the catalyst is the cat-3 catalyst.

Mixing Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 250 ℃ and water vapor, atomizing the mixture by the water vapor, sending the mixture into a first turbulent bed reactor, enabling the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the water vapor to be 1:0.35, enabling the mixture to contact with a first catalyst under the conditions that the reaction temperature is 580 ℃, the catalyst-oil ratio of the first catalyst of the first reactor and the Fischer-Tropsch low-carbon saturated hydrocarbon is 20 and the weight hourly space velocity is 45h ^-1, and carrying out catalytic thermal cracking reaction to obtain a first reactant stream. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

Mixing Fischer-Tropsch light oil and water vapor preheated to 200 ℃ and sending the mixture into a second bubbling bed reactor by utilizing water vapor atomization, wherein the mass ratio of the Fischer-Tropsch light oil to the water vapor is 1:0.25, the Fischer-Tropsch light oil is mixed with a first reactant flow after entering the second reactor, and the mixture is contacted with the second catalyst for catalytic cracking reaction under the conditions that the reaction temperature is 530 ℃, the catalyst-oil ratio of the second catalyst of the second reactor and the Fischer-Tropsch light oil is 20 and the weight hourly space velocity is 45h ^-1, so that a second reactant flow is obtained. The second reactant stream carries the reacted second catalyst to the third reactor.

Mixing Fischer-Tropsch heavy oil preheated to 180 ℃ and water vapor, atomizing the mixture by the water vapor, sending the mixture into a third bulk fluidized bed reactor, wherein the mass ratio of the Fischer-Tropsch heavy oil to the water vapor is 1:0.35, mixing the Fischer-Tropsch heavy oil with a second reactant stream after entering the third reactor, contacting the mixture with the third catalyst under the conditions that the reaction temperature is 490 ℃ and the catalyst-to-oil ratio of the third catalyst and the Fischer-Tropsch heavy oil of the third reactor is 2.4 and the weight hourly space velocity is 4.5h ^-1, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.3MPa, the reaction product is fractionated to obtain gas phase products, light oil and heavy oil, wherein the gas phase products pass through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 30% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 25% of the aromatic raffinate oil is returned to the second reactor for recycling.

Example 4

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 20:20:60, and the catalyst is the cat-4 catalyst.

Mixing the Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 280 ℃ with dry gas, atomizing the mixture by the dry gas, sending the mixture into a first conveying bed reactor, enabling the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the dry gas to be 1:0.25, enabling the mixture to be in contact with a first catalyst under the conditions that the reaction temperature is 530 ℃, the catalyst-oil ratio of the first catalyst of the first reactor and the Fischer-Tropsch low-carbon saturated hydrocarbon is 6, and the weight hourly space velocity is 100h ^-1, and carrying out catalytic pyrolysis to obtain a first reactant flow. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

The Fischer-Tropsch light oil and dry gas preheated to 250 ℃ are mixed and sent into a second rapid bed reactor by utilizing dry gas atomization, the mass ratio of the Fischer-Tropsch light oil to the dry gas is 1:0.18, the Fischer-Tropsch light oil is mixed with a first reactant flow after entering the second reactor, and the mixture is contacted with the second catalyst for catalytic cracking reaction under the conditions that the reaction temperature is 530 ℃, the catalyst-oil ratio of the second catalyst of the second reactor and the Fischer-Tropsch light oil is 25 and the weight hourly space velocity is 75h ^-1, so that a second reactant flow is obtained. The second reactant stream carries the reacted second catalyst to the third reactor.

Mixing Fischer-Tropsch heavy oil and dry gas preheated to 180 ℃ and sending the mixture into a third turbulent bed reactor by utilizing dry gas atomization, wherein the mass ratio of the Fischer-Tropsch heavy oil to the dry gas is 1:0.3, mixing the Fischer-Tropsch heavy oil with a second reactant stream after entering the third reactor, contacting the Fischer-Tropsch heavy oil with the third catalyst under the conditions that the reaction temperature is 430 ℃, the catalyst-to-oil ratio of the third catalyst of the third reactor to the Fischer-Tropsch heavy oil is 5.5 and the weight hourly space velocity is 10h ^-1, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.3MPa, the reaction product is fractionated to obtain gas phase products, light oil and heavy oil, wherein the gas phase products pass through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 40% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 35% of the aromatic raffinate oil is returned to the second reactor for recycling.

Steam stripping the spent catalyst in the stripping section, feeding the spent catalyst into a burning tank through a spent pipe, contacting with oxygen-containing high-temperature flue gas from a combustion furnace to burn, and feeding the spent catalyst to a regenerator to thoroughly burn off carbon deposit. The temperature of the burning and the regeneration is 680 ℃ and the pressure is 0.3MPa, so as to obtain the regenerated catalyst, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor for recycling through the regeneration pipe I, the regeneration pipe II and the regeneration pipe III. And calculating to obtain the carbon deposition by measuring the carbon content in the catalyst to be regenerated.

Example 5

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 25:30:45, and the catalyst is the cat-5 catalyst.

Mixing the Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 250 ℃ with dry gas, atomizing the mixture by the dry gas, feeding the mixture into a first rapid bed reactor, enabling the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the dry gas to be 1:0.6, enabling the mixture to contact with a first catalyst under the conditions that the reaction temperature is 670 ℃, the catalyst-oil ratio of the first catalyst of the first reactor to the Fischer-Tropsch low-carbon saturated hydrocarbon is 15, and the weight hourly space velocity is 120h ^-1, and enabling the mixture to undergo catalytic pyrolysis reaction to obtain a first reactant stream. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

The Fischer-Tropsch light oil and dry gas preheated to 200 ℃ are mixed and sent into a second turbulent bed reactor by utilizing dry gas atomization, the mass ratio of the Fischer-Tropsch light oil to the dry gas is 1:0.3, the Fischer-Tropsch light oil is mixed with a first reactant flow after entering the second reactor, and the Fischer-Tropsch light oil is contacted with the second catalyst for catalytic cracking reaction under the conditions that the reaction temperature is 610 ℃, the catalyst-oil ratio of the second catalyst of the second reactor and the Fischer-Tropsch light oil is 8, and the weight hourly space velocity is 100h ^-1, so that a second reactant flow is obtained. The second reactant stream carries the reacted second catalyst to the third reactor.

Mixing Fischer-Tropsch heavy oil and dry gas preheated to 150 ℃ and sending the mixture into a third bubbling bed reactor by utilizing dry gas atomization, wherein the mass ratio of the Fischer-Tropsch heavy oil to the dry gas is 1:0.18, mixing the Fischer-Tropsch heavy oil with a second reactant stream after entering the third reactor, contacting the Fischer-Tropsch heavy oil with the third catalyst under the conditions that the reaction temperature is 530 ℃, the catalyst-oil ratio of the third catalyst of the third reactor to the Fischer-Tropsch heavy oil is 6.2 and the weight hourly space velocity is 8h ^-1, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant stream.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.5MPa, the reaction product is fractionated to obtain gas phase products, light oil and heavy oil, wherein the gas phase products pass through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 50% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 45% of the aromatic raffinate oil is returned to the second reactor for recycling.

Steam stripping the spent catalyst in the stripping section, feeding the spent catalyst into a burning tank through a spent pipe, contacting with oxygen-containing high-temperature flue gas from a combustion furnace to burn, and feeding the spent catalyst to a regenerator to thoroughly burn off carbon deposit. The temperature of the burning and the regeneration is 630 ℃ and the pressure is 0.5MPa, so as to obtain the regenerated catalyst, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor for recycling through the regeneration pipe I, the regeneration pipe II and the regeneration pipe III. And calculating to obtain the carbon deposition by measuring the carbon content in the catalyst to be regenerated.

Example 6

The mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon to the Fischer-Tropsch light oil to the Fischer-Tropsch heavy oil is 30:40:30, and the catalyst is the cat-6 catalyst.

Mixing the Fischer-Tropsch low-carbon saturated hydrocarbon preheated to 280 ℃ and water vapor, atomizing the mixture by the water vapor, sending the mixture into a first turbulent bed reactor, enabling the mixture to contact with a first catalyst under the conditions that the reaction temperature is 680 ℃, the reaction pressure is 0.2MPa, the catalyst-oil ratio of the first catalyst of the first reactor and the Fischer-Tropsch low-carbon saturated hydrocarbon is 10 and the weight hourly space velocity is 180h ^-1, and carrying out catalytic thermal cracking reaction to obtain a first reactant flow. The first reactant stream carries the reacted first catalyst upward and enters the second reactor.

The Fischer-Tropsch light oil preheated to 250 ℃ and water vapor are mixed and sent into a second bubbling bed reactor by utilizing water vapor atomization, the Fischer-Tropsch light oil and water vapor are mixed with a first reactant flow after entering the second reactor, and the mixture is contacted with the second catalyst and subjected to catalytic cracking reaction under the conditions that the reaction temperature is 630 ℃, the reaction pressure is 0.2MPa, the catalyst-oil ratio of the second catalyst of the second reactor and the Fischer-Tropsch light oil is 5, and the weight hourly space velocity is 120h ^-1, so that a second reactant flow is obtained. The second reactant stream carries the reacted second catalyst to the third reactor.

Mixing Fischer-Tropsch heavy oil and water vapor preheated to 180 ℃ and sending the mixture into a third bulk fluidized bed reactor by utilizing water vapor atomization, wherein the mass ratio of the Fischer-Tropsch heavy oil to the water vapor is 1:0.2, the Fischer-Tropsch heavy oil is mixed with a second reactant flow after entering the third reactor, and the mixture is contacted with the third catalyst and undergoes catalytic cracking and aromatization reactions under the conditions that the reaction temperature is 460 ℃, the reaction pressure is 0.2MPa, the catalyst-oil ratio of the third catalyst of the third reactor to the Fischer-Tropsch heavy oil is 13 and the weight hourly space velocity is 16h ^-1, so that a third reactant flow is obtained.

And the third reaction material flow carries the reacted third catalyst upward, the reaction product and the spent catalyst are obtained by settling separation in a settling vessel under the operating pressure of 0.2MPa, the reaction product is fractionated to obtain gas phase products, light oil and heavy oil, wherein the gas phase products pass through an olefin separation unit to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, and the light oil enters an aromatic hydrocarbon extraction unit to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil. Wherein 60% of the low-carbon saturated hydrocarbon is returned to the first reactor for recycling, and 55% of the aromatic raffinate oil is returned to the second reactor for recycling.

Steam stripping the spent catalyst in the stripping section, feeding the spent catalyst into a burning tank through a spent pipe, contacting with oxygen-containing high-temperature flue gas from a combustion furnace to burn, and feeding the spent catalyst to a regenerator to thoroughly burn off carbon deposit. The temperature of the burning and the regeneration is 700 ℃ and the pressure is 0.2MPa, so as to obtain the regenerated catalyst, and the regenerated catalyst is respectively circulated back to the first reactor, the second reactor and the third reactor for recycling through the regeneration pipe I, the regeneration pipe II and the regeneration pipe III. And calculating to obtain the carbon deposition by measuring the carbon content in the catalyst to be regenerated.

The product distribution of this example is shown in Table 5.

Table 5 product distribution of examples and comparative examples

The gas phase product, light oil, heavy oil, char, olefin and aromatic hydrocarbon yields described in the examples and comparative examples above were calculated based on the total hydrocarbon content in the feed.

As can be seen from table 5, the gas phase product of comparative example 1 is higher than example 1, the light oil phase is lower than example 1, the heavy oil phase is higher than example 1, and the low carbon olefin yield and the aromatic hydrocarbon yield are lower than example 1, wherein the aromatic hydrocarbon yield is only 6.5%. This means that all the raw materials are reacted in the first reactor, which is disadvantageous in that more target products are obtained. The gas phase product of comparative example 2 was lower than that of example 1, the light and heavy oil phases were substantially comparable to example 1, and the yields of light olefins and aromatics were less than that of example 1. This means that the total feed to the third reactor is not conducive to obtaining more of the desired product.

As can be seen from the remaining examples, if the reaction temperature is increased, more gas phase product can be obtained. If the reaction temperature is lowered, more liquid phase products (the resulting light and heavy oils are collectively referred to as "liquid phase products") can be obtained relative to the gas phase products. For example, example 1 had a higher reaction temperature than example 3, example 1 had a higher gas phase product yield than example 3, and example 1 had a lower liquid phase product than example 3. If the proportion of Fischer-Tropsch heavy oil in the raw material is increased, the yield of liquid-phase products and aromatic hydrocarbon can be improved. If the proportion of the low-carbon saturated hydrocarbon and the Fischer-Tropsch light oil in the raw materials is increased, more gas-phase products and low-carbon olefin yields can be obtained. For example, the Fischer-Tropsch heavy oil in example 3 accounts for 90% of the raw material, the Fischer-Tropsch heavy oil in example 6 accounts for only 30% of the raw material, the liquid phase product yield and the aromatic hydrocarbon yield of example 3 are higher than those of example 6, and the gas phase product yield and the low carbon olefin yield of example 3 are lower than those of example 6. In various reaction conditions, the aromatic hydrocarbon yield is above 30% (30.4-37.4%) and the olefin yield is above 39% (39.1-55.1%) in each example.

While the embodiments of the present invention have been described in detail, it will be apparent to those skilled in the art that many modifications and variations can be made without departing from the essential spirit of the invention, and all such modifications and variations are intended to be included within the scope of the invention.

Claims

(1) Feeding Fischer-Tropsch low-carbon saturated hydrocarbon and an atomization medium into a first reactor in an atomization mode, contacting with a first catalyst, performing catalytic pyrolysis reaction to obtain a first reactant flow, and feeding the first reactant flow into a second reactor, wherein in the step (1), the reaction condition of the first reactor is that the temperature is 500-750 ℃, the pressure is 0.01-0.7MPa, the weight hourly space velocity is 10-300h ^-1, and the catalyst-oil ratio is 0.5-50;

(2) Feeding Fischer-Tropsch light oil and an atomizing medium into a second reactor in an atomizing mode, mixing the Fischer-Tropsch light oil and the atomizing medium with the first reactant flow, contacting the mixture with a second catalyst, and carrying out catalytic cracking reaction to obtain a second reactant flow, and feeding the second reactant flow into a third reactor, wherein in the step (2), the reaction condition of the second reactor is that the temperature is 450-700 ℃, the pressure is 0.01-0.7MPa, the weight hourly space velocity is 1-150h ^-1, and the catalyst-oil ratio is 1-40;

(3) Feeding Fischer-Tropsch heavy oil and an atomizing medium into a third reactor in an atomizing mode, mixing the Fischer-Tropsch heavy oil and the atomizing medium with the second reactant flow, contacting the mixture with a third catalyst, and carrying out catalytic cracking and aromatization reaction to obtain a third reactant flow, wherein in the step (3), the reaction condition of the third reactor is that the temperature is 400-650 ℃, the pressure is 0.01-0.7MPa, the weight hourly space velocity is 0.5-30h ^-1, and the catalyst-oil ratio is 1-20;

(4) Carrying out sedimentation separation on the third reaction stream obtained in the step (3) to remove a catalyst to be regenerated from the third reaction stream, fractionating the obtained reaction product to obtain a gas-phase product, light oil and heavy oil, carrying out olefin separation on the gas-phase product to obtain dry gas, low-carbon saturated hydrocarbon and low-carbon olefin, carrying out aromatic extraction on the light oil to obtain aromatic hydrocarbon and aromatic hydrocarbon raffinate oil, carrying out steam stripping on the catalyst to be regenerated, optionally burning and regenerating to obtain a regenerated catalyst, wherein the regenerated catalyst is respectively returned to the first reactor, the second reactor and the third reactor for recycling,

Wherein the mass ratio of the Fischer-Tropsch low-carbon saturated hydrocarbon, the Fischer-Tropsch light oil and the Fischer-Tropsch heavy oil is (5-30): 5-40): 30-90.

2. The process of claim 1, wherein the process further comprises returning the lower saturated hydrocarbons and aromatic raffinate oil obtained in step (4) to the first reactor and the second reactor, respectively, for reprocessing.

3. The method of claim 1, wherein in step (1), step (2) or step (3), the atomizing medium is selected from methanol, ethanol, propanol, dry gas, nitrogen or water vapor, or mixtures thereof.

4. A method as claimed in claim 3, wherein the dry gas comprises one or more of hydrogen, methane and ethane.

5. The process of any one of claims 1-4, wherein in step (1), step (2) or step (3), the mass ratio of the fischer-tropsch light saturated hydrocarbon, the fischer-tropsch light oil or the fischer-tropsch heavy oil to the atomising medium is 1 (0.1-1).

6. The method of any one of claims 1-4, wherein in step (1), step (2), or step (3), the mass ratio of the fischer-tropsch light saturated hydrocarbon, the fischer-tropsch light oil, or the fischer-tropsch heavy oil to the atomizing medium is 1:0.1、1:0.15、1:0.18、1:0.2、1:0.25、1:0.3、1:0.35、1:0.4、1:0.45、1:0.5、1:0.55、1:0.6、1:0.65、1:0.7、1:0.75、1:0.8、1:0.85、1:0.9、1:0.95 or 1:1.

7. The process of any one of claims 1-4, wherein in step (1) the weight ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the atomizing medium is from 1 (0.1-0.6), or wherein in step (2) the weight ratio of the Fischer-Tropsch light oil to the atomizing medium is from 1 (0.1-0.8), or wherein in step (3) the weight ratio of the Fischer-Tropsch heavy oil to the atomizing medium is from 1 (0.1-0.8).

8. The process of claim 7, wherein in step (1) the weight ratio of the Fischer-Tropsch low carbon saturated hydrocarbon to the atomizing medium is from 1 (0.15 to 0.6), or wherein in step (2) the weight ratio of the Fischer-Tropsch light oil to the atomizing medium is from 1 (0.15 to 0.5), or wherein in step (3) the weight ratio of the Fischer-Tropsch heavy oil to the atomizing medium is from 1 (0.15 to 0.5).

9. A process according to any one of claims 1 to 3 wherein in step (1), step (2) or step (3) the fischer-tropsch low carbon saturated hydrocarbon, fischer-tropsch light oil or fischer-tropsch heavy oil is preheated before atomisation.

10. The method of claim 9, wherein the fischer-tropsch low carbon saturated hydrocarbon, fischer-tropsch light oil or fischer-tropsch heavy oil is preheated to 100-400 ℃.

11. The process of claim 10, wherein the Fischer-Tropsch low carbon saturated hydrocarbon is preheated to 100-350 ℃, or wherein the Fischer-Tropsch light oil is preheated to 100-350 ℃, or wherein the Fischer-Tropsch heavy oil is preheated to 100-350 ℃.

12. The method of any of claims 1-3, wherein the active component of the first, second, and third catalysts is at least one of an unmodified or modified eight-membered ring molecular sieve, a ten-membered ring molecular sieve, a twelve-membered ring molecular sieve, or a metal oxide.

13. The method of claim 12, wherein the eight-membered, ten-membered, or twelve-membered ring molecular sieve is selected from SAPO-34, SAPO-18, ITQ-13, IM-5, ZSM-11, MCM-22, EU-1, beta, mordenite molecular sieve, or the metal oxide is one or more of zinc oxide, lanthanum oxide, magnesium oxide, manganese oxide, cerium oxide, gallium oxide, chromium oxide, nickel oxide, tungsten oxide.

14. The method of claim 12, wherein the active components of the first, second and third catalysts comprise 20wt% to 60wt% of the catalyst weight on a dry basis.

15. The method according to claim 14, wherein the first catalyst, the second catalyst and the third catalyst contain alumina and/or silica as a carrier in addition to the active component in the remaining amount.

16. The process of any of claims 1-3, wherein the first catalyst is a mixed catalyst of regenerated catalyst and spent catalyst, wherein the carbon content of the first catalyst is from 0wt% to 2.00wt%, or wherein the second catalyst is a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the second catalyst is from 0wt% to 2.0wt%, or wherein the third catalyst is a mixture of regenerated catalyst and spent catalyst, wherein the carbon content of the third catalyst is from 0wt% to 2.0wt%.

17. The process of claim 1, wherein in step (1), the temperature is 580 ℃ to 680 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 40 to 200h ^-1, or the catalyst to oil ratio is 5 to 30.

18. The process of claim 1, wherein in step (2), the temperature is 530 ℃ to 630 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 40 to 120h ^-1, or the agent-to-oil ratio is 5 to 25.

19. The process according to claim 1, wherein in step (3), the temperature is 480 to 580 ℃, or the pressure is 0.1 to 0.5MPa, or the weight hourly space velocity is 2 to 20h ^-1, or the catalyst to oil ratio is 2 to 15.

20. A process according to any one of claims 1 to 3, wherein the first reactor is a transport bed reactor, a fast bed reactor or a turbulent bed reactor, or the second reactor is a fast bed reactor, a turbulent bed reactor or a bubbling bed reactor, or the third reactor is a turbulent bed reactor, a bubbling bed reactor or a bulk fluidized bed reactor.

21. The process of claim 20, wherein the first reactor is a transport bed reactor or a fast bed reactor, or the second reactor is a fast bed reactor or a turbulent bed reactor, or the third reactor is a bubbling bed reactor or a turbulent bed reactor.

22. A process according to any one of claims 1 to 3, wherein in step (4) the settling separation is operated at a pressure of 0.01 to 0.7MPa.

23. The process of claim 2 wherein 10% -90% of the lower saturated hydrocarbons from step (4) are returned to the first reactor for reprocessing or 5% -95% of the aromatic raffinate oil from step (4) is returned to the second reactor for reprocessing.

24. A process according to any one of claims 1 to 3, wherein in step (4) the spent catalyst is contacted with an oxygen-containing gas and optionally burnt and regenerated under conditions of a pressure of 0.01 to 0.7MPa and a temperature of 550 to 750 ℃.

25. The method of claim 24, wherein the oxygen-containing gas is air or oxygen-containing high temperature flue gas.

26. An apparatus for carrying out the process for co-producing light olefins and aromatics from a Fischer-Tropsch synthesis product according to any of the claims 1-25, said apparatus comprising a reaction system, a regeneration system and a product separation system,

Wherein, the reaction system includes:

A first reactor;

a second reactor disposed in series with the first reactor;

a third reactor disposed in series with the second reactor;

Wherein the regeneration system comprises:

a stripping section connected in fluid communication to the settling unit;

Wherein the product separation system comprises:

a fractionation unit connected in fluid communication to the settling unit;

27. The apparatus of claim 26, wherein the regeneration system further comprises:

28. The apparatus of claim 27, wherein a burner is further provided in the regeneration system, the burner being connected in fluid communication to the burn pot to provide oxygen-containing high temperature flue gas into the burn pot.

29. The apparatus of any one of claims 26-28, wherein the first, second and third reactors share a single settler.