An isomeric hydrocarbon conversion apparatus and method of conversion thereof

Abstract

The application discloses a kind of isomeric hydrocarbon conversion device and its conversion method, process flow uses the sequential circulation operation of "reaction-stage cooling separation-distillation", the isomeric hydrocarbon conversion device is circulating reaction device, including the reaction unit, cooling separation unit, rectification unit connected in sequence;The reaction unit includes reactor;The cooling separation unit is two-stage gas-liquid phase separation unit, including the first-stage gas-liquid phase separation device and second-stage gas-liquid phase separation device connected in sequence;The rectification unit includes rectifying column.This method can be used for the continuous production of isomeric hydrocarbon 2-butene, avoids the method that traditional process adds etherification unit to separate isobutene, process is simple, easy to operate, and reduces production cost.

Description

TECHNICAL FIELD

[0001] The application relates to a device for converting isomeric hydrocarbons and a conversion method thereof, and belongs to the technical field of chemical industry. BACKGROUND

[0002] Isobutylene is one of the typical carbon four by-products in the petroleum refining industry, which is mainly used for oil blending and methyl tert-butyl ether (MTBE) synthesis, production of butyl rubber, methacrylonitrile and antioxidant and other chemical products, and the market demand is limited. At the same time, with the rise of emerging industries such as ethanol biofuel, ethanol gasoline has been promoted, and MTBE and other oxygen-containing compounds cannot continue to be used as gasoline additive components, and the market demand for isobutylene further shrinks, and developing new isobutylene downstream derivative production process becomes a problem to be solved.

[0003] Chinese patent CN112441865 discloses a method for preparing n-butene from isobutylene. The method adopts two-step hydrogen-free reaction, and isobutylene is normal to butene-1 intermediate product, and then butene-1 is isomerized to butene-2.

[0004] Chinese patent CN112441866 discloses a method for preparing n-butene from isobutylene. The method introduces etherification reaction and separation device to realize the purification of isobutylene in carbon four raw materials, and then realizes the generation of n-butene product through hydrogen-free isomerization.

[0005] Chinese patent CN108997075 discloses an isobutylene isomerization method. The isomerization catalyst is synthesized by using the calcined product of hydrotalcite as a carrier and loading platinum group metal, the selectivity of the target product is 99.87%, and the maximum yield of n-butene is 47.28%.

[0006] The above inventions all explore the preparation of n-butene from isobutylene, and the main content is the development of catalysts, and the flow design does not consider the separation and recycling of carrier gas. SUMMARY

[0007] The application provides an isomeric hydrocarbon conversion device and a conversion method thereof. The device realizes carrier gas separation and recycling through two-stage condensation separation, and realizes the separation of a "non-condensable gas-raw material-product" system through fractional condensation rectification, thereby simplifying the production process and reducing the production cost.

[0008] In one aspect of the application, an isomeric hydrocarbon conversion device is provided, and the isomeric hydrocarbon conversion device is a circulating reaction device.

[0009] The isomeric hydrocarbon conversion device comprises a reaction unit, a cooling and separation unit and a rectification unit connected in sequence.

[0010] The reaction unit comprises a reactor, and the reactor comprises a reactor inlet and a reaction product outlet.

[0011] The cooling separation unit is a two-stage gas-liquid phase separation unit, comprising a first-stage gas-liquid phase separation device and a second-stage gas-liquid phase separation device connected in sequence;

[0012] The first-stage gas-liquid phase separation device is provided with a first inlet, a gas phase outlet I and a liquid phase outlet I; the second-stage gas-liquid phase separation device is provided with a second inlet, a gas phase outlet II and a liquid phase outlet II;

[0013] The reaction product outlet is in communication with the first inlet through a pipeline, and the gas phase outlet I is in communication with the second inlet through a pipeline; the gas phase outlet II is in communication with the reactor inlet pipeline;

[0014] The rectification unit comprises a rectification column, which comprises a rectification unit inlet I, a rectification unit inlet II and a rectification unit liquid phase outlet I located at the bottom of the rectification column;

[0015] The liquid phase outlet I and the liquid phase outlet II are in pipeline communication with the rectification unit inlet I and the rectification unit inlet II, respectively.

[0016] Optionally, the rectification column further comprises a rectification unit liquid phase outlet II and a rectification unit gas phase outlet, and the rectification unit liquid phase outlet II is in pipeline communication with the reactor inlet.

[0017] Optionally, the isomeric hydrocarbon compound conversion device further comprises a raw material supply end I and a raw material supply end II;

[0018] The reaction unit further comprises a preheater I and a preheater II;

[0019] The raw material supply end I, the preheater I and the reactor inlet are in sequential communication through pipelines;

[0020] The raw material supply end II, the preheater II and the reactor inlet are in sequential communication through pipelines.

[0021] Optionally, a cooling device I is arranged on the pipeline in communication between the reaction product outlet and the first inlet;

[0022] A cooling device II is arranged on the pipeline in communication between the gas phase outlet I and the second inlet.

[0023] Optionally, a pressure boosting device is arranged on the pipeline in communication between the gas phase outlet II and the reactor inlet.

[0024] Optionally, the number of theoretical plates of the rectification column is 30-110;

[0025] Optionally, the upper limit of the number of theoretical plates of the rectification column can be independently selected from 45, 65, 85, 100 and 110, and the lower limit can be independently selected from 30, 45, 65, 85 and 100.

[0026] Optionally, the reflux ratio of the rectification tower is 5-50.

[0027] In another aspect of the present application, a method for converting isomeric hydrocarbons is provided, which comprises: feeding a raw material containing hydrogen and isobutene into a reaction device containing a catalyst through a reactor inlet, and obtaining a product containing 2-butene by reaction;

[0028] In another aspect of the present application, a method for converting isomeric hydrocarbons is provided, which comprises: feeding a raw material containing hydrogen and isobutene into a reaction device containing a catalyst through a reactor inlet, and obtaining a product containing 2-butene by reaction;

[0029] Optionally, the method comprises the following steps:

[0030] (1) feeding a raw material containing hydrogen and isobutene into a reactor through a reactor inlet to generate a reaction product by catalytic reaction;

[0031] In another aspect of the present application, a method for converting isomeric hydrocarbons is provided, which comprises: feeding a raw material containing hydrogen and isobutene into a reaction device containing a catalyst through a reactor inlet, and obtaining a product containing 2-butene by reaction;

[0032] (2) separating the reaction product into a gas phase I and a liquid phase I by a first-stage gas-liquid separation device; and cooling and separating the gas phase I by a second-stage gas-liquid separation device to obtain a gas phase II and a liquid phase II;

[0033] The gas phase II enters the reactor through a gas phase outlet II;

[0034] The liquid phase I enters the rectification tower through a liquid phase outlet II;

[0035] The liquid phase II enters the rectification tower through a liquid phase outlet II;

[0036] (3) separating the liquid phase I and the liquid phase II by the rectification tower to obtain a product containing 2-butene, a liquid phase raw material, and a gas phase III;

[0037] The gas phase III is discharged through a gas phase outlet of the rectification unit, the product containing 2-butene is discharged through a liquid phase outlet I of the rectification unit, and the liquid phase raw material enters the reactor through a liquid phase outlet II of the rectification unit.

[0038] Optionally, the gas phase II is a mixed gas containing hydrogen

[0039] Optionally, the cooling temperature of the first-stage gas-liquid separation device is 42-65°C;

[0040] Optionally, the upper limit of the cooling temperature of the first-stage gas-liquid separation device can be independently selected from 45°C, 50°C, 55°C, 60°C, and 65°C; and the lower limit can be independently selected from 42°C, 45°C, 50°C, 55°C, and 60°C.

[0041] Optionally, the cooling temperature of the second-stage gas-liquid phase separation device is -60 to -10℃.

[0042] Optionally, the upper limit of the cooling temperature of the second-stage gas-liquid phase separation device is independently selected from -50℃, -40℃, -30℃, -20℃, -10℃; and the lower limit is independently selected from -60℃, -50℃, -40℃, -30℃, -20℃.

[0043] Optionally, the operating pressure of the rectification tower is 0.1 to 3.0 MPa.

[0044] Optionally, the upper limit of the operating pressure of the rectification tower is independently selected from 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa; and the lower limit is independently selected from 0.1 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa.

[0045] Optionally, the overhead temperature of the rectification tower is -40 to 42℃.

[0046] Optionally, the upper limit of the overhead temperature of the rectification tower is independently selected from -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 42℃; and the lower limit is independently selected from -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃.

[0047] Optionally, the catalytic reaction temperature is 450 to 600℃.

[0048] Optionally, the upper limit of the catalytic reaction temperature is independently selected from 500℃, 550℃, 600℃; and the lower limit is independently selected from 450℃, 500℃, 550℃.

[0049] Optionally, the liquid-phase raw material is preheated by the preheater II and then enters the reactor.

[0050] The gas phase II is preheated by the preheater I and then enters the reactor.

[0051] The raw material containing hydrogen and isobutene is preheated by the preheater I and the preheater II and then enters the reactor.

[0052] Optionally, the gas phase II is pressurized by the pressurizing device and then enters the reactor.

[0053] Optionally, the liquid-phase raw material is an isobutene raw material with a molar fraction of ≥90%.

[0054] Optionally, in the product containing 2-butene, the mass content of 2-butene is >85%.

[0055] As a specific embodiment, the isomeric hydrocarbon conversion device comprises the following components:

[0056] A hydrogen preheater 1, a feedstock preheater 2, a normal reactor 3, a condenser 4, a cooling separation tank 5 (i.e. a first-stage gas-liquid phase separation device), a cryogenic separator 6, a cryogenic separation tank 7 (i.e. a second-stage gas-liquid phase separation device), a circulating hydrogen compressor 8, and a separation column 9.

[0057] As a specific embodiment, the isomeric hydrocarbon conversion method comprises the following steps:

[0058] S001: hydrogen and isobutene feedstock are heated to reaction temperature in a hydrogen preheater 1 and a feedstock preheater 2 respectively, and then sent to a normal reactor 3;

[0059] S002: the reaction feedstock is subjected to catalytic reaction in the normal reactor 3 to obtain a normal reaction product;

[0060] S003: the normal reaction product is cooled and separated in a condenser 4, and then subjected to gas-liquid phase separation in a cooling separation tank 5;

[0061] S004: the gas phase separated from the cooling separation tank 5 is subjected to deep cooling in a cryogenic separator 6, and then subjected to secondary phase separation in a cryogenic separation tank 7, and the gas phase is pressurized by a circulating hydrogen compressor 8 and recycled;

[0062] S005: the liquid phase at the bottom of the cooling separation tank 5 and the cryogenic separation tank 7 is sent to a separation column 9, and subjected to mass transfer separation, and non-condensable gas is discharged at the top of the column, and unreacted feedstock is separated and recycled, and 2-butene product is obtained at the bottom of the column.

[0063] The application can produce the following beneficial effects:

[0064] The method can continuously produce 2-butene product from isobutene feedstock, avoids multi-unit joint operation, reduces production cost, and simplifies operation process. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 FIG. 1 is a schematic diagram of an isomeric hydrocarbon conversion device according to the application.

[0066] Wherein:

[0067] 1, hydrogen preheater; 2, feedstock preheater; 3, normal reactor; 3-1, reactor inlet; 3-2, reaction product outlet; 4, condenser; 5, cooling separation tank; 5-1, first inlet; 5-2, gas phase outlet I; 5-3, liquid phase outlet I; 6, cryogenic cooler; 7, cryogenic separation tank; 7-1, second inlet; 7-2, liquid phase outlet II; 7-3, gas phase outlet II; 8, circulating hydrogen compressor; 9, rectification column; 9-1, rectification unit inlet I; 9-2, rectification unit inlet II; 9-3, rectification unit liquid phase outlet I; 9-4, rectification unit liquid phase outlet II; 9-5, rectification unit gas phase outlet. DETAILED DESCRIPTION

[0068] The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

[0069] The feedstock and catalyst in the examples of the present application are all purchased through commercial channels unless otherwise specified.

[0070] Example 1

[0071] One embodiment of the present application, an isomeric hydrocarbon conversion device as shown in FIG. 1, includes: Figure 1

[0072] The hydrogen preheater 1 and the feedstock preheater 2 are respectively connected to the reactor inlet 3-1 of the normal reactor 3, and the reaction product outlet 3-2 of the normal reactor 3 is connected to the first inlet 5-1 of the cooling separation tank 5 (first-stage gas-liquid phase separation device) through the condenser 4; the gas phase outlet I 5-2 of the cooling separation tank 5 is connected to the second inlet 7-1 of the cryogenic separation tank 7 (second-stage gas-liquid phase separation device) through the cryogenic cooler 6; the gas phase outlet II of the cryogenic separation tank 7 is connected to the hydrogen preheater 1 through the circulating hydrogen compressor 8; the liquid phase outlet I 5-3 of the cooling separation tank 5 and the liquid phase outlet II 7-3 of the cryogenic separation tank 7 are respectively connected to the rectification unit inlet I 9-1 and the rectification unit inlet II 9-2 of the rectification column 9; the rectification unit liquid phase outlet II 9-4 of the rectification column 9 is connected to the feedstock preheater 2, and the rectification column 9 is further provided with the rectification unit liquid phase outlet II 9-4; and the rectification unit gas phase outlet 9-5.

[0073] Example 2

[0074] ​The recycled hydrogen and fresh hydrogen are mixed and heated to 560℃ in a hydrogen preheater 1, the recycled isobutene and fresh isobutene are mixed and heated to 560℃ in a raw material preheater 2, then mixed with the heated hydrogen and sent to a normalizer 3 through an inlet 3-1 to undergo normalizing reaction to generate normalizing reaction product, the reaction uses ZSM-5 molecular sieve catalyst loaded with Pt metal, the molar ratio of hydrogen to isobutene is 0.5:1, and the reaction pressure is 2.4 MPa. The normalizing reaction product is cooled to 42℃ in a condenser 4 through an outlet 3-2 to divide into gas and liquid two phases, and the gas-liquid phase separation is realized in a cooling separation tank 5, the separated gas phase I is deep-cooled to -30℃ in a deep-cooling device 6 to be separated again, and the secondary phase separation is realized in a deep-cooling separation tank 7, the gas phase II contains hydrogen with a molar fraction of 98.48%, and the gas phase II is pressurized to 3 MPa by a recycled hydrogen compressor 8 and recycled. The liquid phase I and liquid phase II at the bottom of the cooling separation tank 5 and the deep-cooling separation tank 7 are sent to a rectifying column 9, the operation pressure of the rectifying column 9 is 0.7 MPa, the top temperature is 42℃, and 65 theoretical plates are provided. A split condenser is provided at the top of the rectifying column 9, a small amount of gas phase III containing hydrogen is separated as incondensable waste gas, the liquid phase obtained at the top is recycled isobutene raw material with a molar fraction of 90%, and the product 2-butene with a mass fraction of more than 85% is obtained at the bottom.

[0075] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed above, the present application is not limited thereto. Any person skilled in the art can make some changes or modifications to the above disclosed technical contents without departing from the scope of the present application, and such changes or modifications are equivalent to equivalent embodiments, and are within the scope of the technical solution.

Claims

1. A device for converting isomeric hydrocarbons, characterized in that, The isomeric hydrocarbon conversion device is a cyclic reaction device; The isomeric hydrocarbon conversion device includes a reaction unit, a cooling and separation unit, and a distillation unit connected in sequence. The reaction unit includes a reactor, which includes a reactor inlet and a reaction product outlet. The cooling separation unit is a two-stage gas-liquid phase separation unit, comprising a first-stage gas-liquid phase separation device and a second-stage gas-liquid phase separation device connected in sequence. The first-stage gas-liquid phase separation device is equipped with a first inlet, a gas phase outlet I, and a liquid phase outlet I; the cooling temperature of the first-stage gas-liquid phase separation device is 42~65℃. The second-stage gas-liquid phase separation device is equipped with a second inlet, a gas phase outlet II, and a liquid phase outlet II; the cooling temperature of the second-stage gas-liquid phase separation device is -60~-10℃, and it separates gas phase II and liquid phase II respectively; The reaction product outlet is connected to the first inlet via a pipeline, the gas phase outlet I is connected to the second inlet via a pipeline, the gas phase outlet II is connected to the reactor inlet pipeline, the gas phase II enters the reactor through the gas phase outlet II, and the gas phase II is a mixed gas containing hydrogen. The distillation unit includes a distillation column, which includes a distillation unit inlet I, a distillation unit inlet II, and a distillation unit liquid phase outlet I located at the bottom of the distillation column; The liquid phase outlet I and liquid phase outlet II are respectively connected to the distillation unit inlet I and distillation unit inlet II pipelines.

2. The isomeric hydrocarbon conversion device according to claim 1, characterized in that, The distillation column also includes a liquid phase outlet II of the distillation unit and a gas phase outlet of the distillation unit, wherein the liquid phase outlet II of the distillation unit is connected to the inlet pipeline of the reactor.

3. The isomeric hydrocarbon conversion device according to claim 1, characterized in that, The heterogeneous hydrocarbon conversion device also includes a raw material supply end I and a raw material supply end II; The reaction unit also includes preheater I and preheater II; The raw material supply end I, the preheater I, and the reactor inlet are connected in sequence via pipelines; The raw material supply end II, the preheater II, and the reactor inlet are connected in sequence via pipelines.

4. The isomeric hydrocarbon conversion device according to claim 1, characterized in that, A cooling device I is provided on the pipeline connecting the reaction product outlet and the first inlet; A cooling device II is installed on the pipeline connecting the gas phase outlet I and the second inlet.

5. The isomeric hydrocarbon conversion device according to claim 1, characterized in that, A pressurization device is installed on the pipeline connecting the gas phase outlet II to the reactor inlet.

6. The isomeric hydrocarbon conversion device according to claim 1, characterized in that, The theoretical number of plates in the distillation column is 30 to 110. The reflux ratio of the distillation column is 5 to 50.

7. A method for converting isomeric hydrocarbons, characterized in that, The conversion method includes: a raw material containing hydrogen and isobutene is introduced into a reaction device equipped with a catalyst through a reactor inlet, and the reaction is carried out to obtain a product containing 2-butene; The reaction apparatus is selected from the isomeric hydrocarbon conversion apparatus according to any one of claims 1 to 6.

8. The conversion method according to claim 7, characterized in that, Includes the following steps: (1) Raw materials containing hydrogen and isobutylene enter the reactor through the reactor inlet and undergo a catalytic reaction to obtain reaction products; The reactor contains a catalyst; (2) The reaction products are separated into gas phase I and liquid phase I by the first-stage gas-liquid phase separation device; gas phase I enters the second-stage gas-liquid phase separation device through gas phase outlet I for secondary cooling and separation, and gas phase II and liquid phase II are separated. The gas phase II enters the reactor through gas phase outlet II; The liquid phase I enters the distillation column through the liquid phase outlet II; The liquid phase II enters the distillation column through the liquid phase outlet II; (3) The liquid phase I and liquid phase II are separated by distillation in a distillation column to obtain a product containing 2-butene, a liquid raw material and a gas phase III; The gas phase III is discharged through the gas phase outlet of the distillation unit, the product containing 2-butene is discharged through the liquid phase outlet I of the distillation unit, and the liquid phase feedstock enters the reactor through the liquid phase outlet II of the distillation unit.

9. The conversion method according to claim 8, characterized in that, The gas phase II is a mixture containing hydrogen; The cooling temperature of the first-stage gas-liquid phase separation device is 42~65℃; The cooling temperature of the second-stage gas-liquid phase separation device is -60~-10℃; The operating pressure of the distillation column is 0.1~3.0 MPa; The top temperature of the distillation column is -40~42℃. o C; The catalytic reaction temperature is 450℃~600℃.

10. The conversion method according to claim 8, characterized in that, The liquid raw material is preheated by preheater II before entering the reactor; The gas phase II enters the reactor after being preheated by preheater I; The raw materials containing hydrogen and isobutylene are preheated by preheater I and preheater II respectively before entering the reactor; The gas phase II is pressurized by a pressurizing device before entering the reactor; The liquid phase raw material is isobutylene with a molar fraction ≥90%; In the product containing 2-butene, the mass content of 2-butene is >85%.

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