WO2025025885A1 - Reactor for preparing olefin by means of hydrogenation of carbon dioxide, and working method thereof and use thereof - Google Patents

Abstract

Disclosed are a reactor for preparing an olefin by means of hydrogenation of carbon dioxide, and a working method thereof and the use thereof. The reactor for preparing an olefin by means of hydrogenation of carbon dioxide comprises an outer shell and an inner shell, wherein the outer shell is used for the reaction of carbon dioxide with hydrogen to synthesize methanol, and is provided with a catalyst inlet for feeding a catalyst and an external reaction heat collector for leading out reaction heat in the outer shell; the inner shell is used for the dehydration reaction of the methanol to synthesize the olefin; the inner shell is arranged in the outer shell and is provided with a heater for heating reaction materials, an internal reaction heat collector for leading out the reaction heat in the inner shell, and a first inlet and a first outlet for circulating the reaction materials between the inner shell and the outer shell.

Description

Carbon dioxide hydrogenation to olefins reactor and its working method and application

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 2023109668879 filed in China on August 2, 2023, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates to the technical field of energy conservation and emission reduction, and in particular to a carbon dioxide hydrogenation to olefins reactor and a working method and application thereof.

Background Art

Climate change is a major challenge facing the world and a major global issue that has a profound impact on the economic and social development and ecological environment of all countries. Relevant research by the International Energy Agency (IEA) shows that in order to achieve the goal of controlling the global average temperature rise within 2°C above the pre-industrial level as set in the Paris Agreement, the emission reduction contribution rate of CCUS will be between 10% and 20% when all types of emission reduction technologies are optimally configured. In other words, if CCUS technology is not used, the goal of controlling the temperature rise by 2°C will not be achieved. Carbon dioxide utilization technology is an important means to achieve the goal of carbon neutrality. _CO2 carbon dioxide production of low-carbon olefins is a _CO2 utilization technology that can convert _CO2 as a resource into high-value olefin products. It is an important means to achieve _CO2 emission reduction from high cost to low cost or even negative cost.

_CO2 chemical utilization can produce a variety of products such as synthesis gas, natural gas, formic acid, methanol, olefins, gasoline, carbonates, urea, etc. Olefins are important basic organic chemical raw materials, especially low-carbon olefins such as ethylene and propylene, which are the most widely used and are the basic raw materials for the three major synthetic materials (plastics, rubber, and fibers). Ethylene and propylene are the chemical products with the highest output value in the world. Olefin production technology and production capacity are important indicators of the development level of a country's petrochemical industry.

At present, the research on catalysts for _CO2 hydrogenation to olefins has made a lot of progress. The more mature synthesis method is a two-step reaction through the methanol route. Usually, the reaction conditions of the two steps of this method are quite different. The use of a traditional single reactor cannot achieve the optimal conditions for each step of the reaction at the same time, resulting in low overall conversion rate and selectivity. If two reactors are used to carry out two reactions separately, the process will be complicated and the initial investment will increase.

Therefore, there is an urgent need to design a single reactor that can carry out two-step reactions while achieving separate control of the reaction conditions of each step, with high conversion rate and selectivity, simple overall process flow, low equipment investment, and high comprehensive benefits.

Summary of the invention

The first embodiment of the present disclosure provides a carbon dioxide hydrogenation to olefins reactor, comprising:

An outer shell, the outer shell is used for synthesizing methanol by reacting carbon dioxide and hydrogen, the outer shell having a catalyst inlet for entering the catalyst and an external reaction heat extractor for extracting the reaction heat in the outer shell;

An inner shell, the inner shell is used for synthesizing olefins by dehydration reaction of methanol; the inner shell is arranged in the outer shell, and the inner shell has a heater for heating reaction materials, an internal reaction heat extractor for extracting reaction heat in the inner shell, and a first inlet and a first outlet for the reaction materials to circulate between the inner shell and the outer shell; the first inlet and the first outlet are arranged opposite to each other, and the first inlet is adjacent to and opposite to the catalyst inlet.

In some embodiments, the inner shell includes a first part and a second part that are interconnected, the first part is provided with the first outlet, the second part is provided with a first inlet, the cross-sections of the first part and the second part along the direction from the first inlet to the first outlet are both isosceles trapezoidal, and the size of the first part at one end where the first outlet is provided and the size of the second part at one end where the first inlet is provided are both smaller than the size of the connection point between the first part and the second part.

In some embodiments, the inner shell and the outer shell are arranged on a co-center line in a direction from the first inlet to the first outlet.

In some embodiments, a middle portion of a cross section of the outer shell along a direction from the first inlet to the first outlet is rectangular.

In some embodiments, the outer shell is cylindrical, and a plurality of second inlets for the raw gases carbon dioxide and hydrogen to enter the inner part of the outer shell are provided on the side wall of the outer shell, and the plurality of second inlets are opened along the tangent direction of the inner wall of the outer shell.

In some embodiments, a plurality of the second inlets are distributed on the outer shell at intervals along the direction of the first inlet and the first outlet, and two adjacent second inlets are arranged relative to or staggered.

In some embodiments, the internal reaction heat collector is disposed on the inner surface and/or outer surface of the inner shell.

In some embodiments, the external reaction heat collector and the product outlet are provided on a side of the outer shell adjacent to the first outlet.

In some embodiments, the heater is installed in the inner shell adjacent to one side of the first inlet, and an airflow multiplier for sucking the catalyst from the catalyst inlet into the inner shell is installed at the first inlet.

In some embodiments, the outer shell has a funnel-shaped structure at one end adjacent to the first inlet, and the catalyst inlet is located on the side of the funnel-shaped structure away from the first inlet; the funnel-shaped structure is mounted on a base, and a vibrator is mounted on the funnel-shaped structure to loosen the catalyst deposited on the side wall of the funnel-shaped structure.

The second aspect of the present disclosure provides a working method of a carbon dioxide hydrogenation to olefins reactor according to any one of the first aspects, including:

Raw gas carbon dioxide and hydrogen are used to synthesize methanol in the outer shell under the action of the catalyst;

Driven by the raw gas, methanol and catalyst are heated and enter the inner shell from the first inlet to synthesize olefins. Hydrocarbons, forming a mixed gas carrying the catalyst;

The mixed gas enters the outer shell from the first outlet, and then a part of it is discharged from the outer shell, and the other part is cooled to form a reaction material circulation between the outer shell and the inner shell;

The temperature of the synthetic methanol and the temperature of the synthetic olefin are controlled respectively via the external reaction heat collector and the internal reactor heat collector.

In some embodiments, the working method further includes the step of introducing raw gas carbon dioxide and hydrogen into the outer shell from multiple second inlets along the inner tangential direction of the outer shell to form a spiral airflow with the catalyst in the outer shell and synthesize methanol.

In some embodiments, the working method further comprises the step of loosening the catalyst deposited on the side wall of the funnel structure by vibrating with a vibrator.

In some embodiments, the working method further includes the step of delivering the raw gas and catalyst into the inner shell through the gas flow multiplier.

In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide and unreacted hydrogen.

In some embodiments, the mixing volume ratio of hydrogen and carbon dioxide in the raw gas is (2-4):1.

In some embodiments, the temperature of the synthesized methanol in the outer shell is 200-300° C. and the pressure is 0.5-8 MPa.

In some embodiments, the temperature of the synthesized olefin in the inner shell is 300-400° C. and the pressure is 0.5-8 MPa.

In some embodiments, the catalyst is a carbon dioxide hydrogenation to olefins catalyst.

In some embodiments, the catalyst is carried by a carrier gas from the catalyst inlet into the outer shell, and the carrier gas is at least one of carbon dioxide, hydrogen, and an inert gas.

The third embodiment of the present disclosure provides a carbon dioxide hydrogenation system for olefins, comprising:

A reactor, wherein the reactor is a carbon dioxide hydrogenation to olefins reactor according to any one of the embodiments of the first aspect of the present disclosure, and a feed gas inlet of the reactor is connected to a first preheater;

A cyclone separator, wherein the inlet of the cyclone separator is connected to the product outlet of the reactor, the gas outlet of the cyclone separator is connected to a gas-liquid separation device, and the solid outlet of the cyclone separator is connected to a catalyst regenerator and a catalyst feed pipeline in sequence;

An olefin separation device, wherein the inlet of the olefin separation device is connected to the gas outlet of the gas-liquid separation device, the impurity outlet of the olefin separation device is connected in sequence to the cold side of the heat exchanger, the second preheater and the catalyst feed pipeline, the hot side of the heat exchanger is connected to the internal reaction heat extractor, and the catalyst feed pipeline is connected to the catalyst inlet.

The fourth aspect of the present disclosure provides a working method of the carbon dioxide hydrogenation to olefins system of any embodiment of the third aspect, including:

After the raw gas carbon dioxide and hydrogen enter the reactor, olefins are synthesized under the action of the catalyst;

The mixed gas carrying the catalyst discharged from the inner shell is partially discharged from the outer shell and then separated by a cyclone separator. The catalyst obtained by the separation treatment is regenerated and then reused in the reactor, and the gas phase obtained by the separation treatment is sequentially treated by a gas-liquid separation device and an olefin separation device to obtain an olefin product and the raw gas that has not been completely reacted;

The unreacted raw gas is heated by the heat medium from the internal reactor heat collector and then preheated to be used as catalyst carrier gas.

In some embodiments, the method for synthesizing olefins after the raw gas carbon dioxide and hydrogen enter the reactor under the action of a catalyst comprises:

introducing the preheated raw gas carbon dioxide and hydrogen into the outer shell;

Turning on the airflow multiplier to establish circulation of the raw gas airflows between the inner shell and the outer shell;

Turning on the heater to heat the temperature of the inner shell adjacent to the first inlet to a methanol-to-olefins temperature, thereby promoting the conversion of methanol into olefins in the inner shell;

Turning on the internal reaction heat collector and the external reaction heat collector to maintain the temperature of each area in the reactor stable;

Opening the product outlet and the catalyst inlet to establish a stable circulation between the reactor and the rest of the carbon dioxide hydrogenation to olefins system;

The carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of the catalyst, and the methanol is synthesized into olefins in the inner shell under the action of the catalyst.

The carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment has at least the following beneficial effects:

Different from traditional reactors that can only maintain one reaction condition, the carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment is a double-shell reactor with dual reaction areas of an inner shell and an outer shell, which can control the methanol synthesis reaction temperature and the olefin synthesis reaction temperature respectively, so as to realize the two-step _CO2 hydrogenation to olefins reaction at the same time. Compared with the traditional single reactor, it solves the problem that the traditional single reactor cannot achieve a high conversion rate and selectivity due to the large difference in the optimal reaction temperature of the two-step reaction; compared with the series multi-stage reactor, it solves the problems of complex multi-reactor process and high initial equipment investment cost. The carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment is used for the _CO2 hydrogenation to olefins reaction, while achieving a high carbon dioxide conversion rate and olefin selectivity, it can maintain a relatively simple process flow and low initial equipment investment.

Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

FIG1 is a schematic structural diagram of a carbon dioxide hydrogenation to olefins reactor according to an embodiment of the present disclosure.

FIG2 is a schematic structural diagram of a carbon dioxide hydrogenation to olefins system according to an embodiment of the present disclosure.

Reference numerals:
1-outer shell; 2-inner shell; 201-first part; 202-second part; 3-first inlet; 4-first outlet; 5-inner reaction heat collector; 501-first sub-heat collector; 502-second sub-heat collector; 6-second inlet; 7-outer reaction heat collector; 8-product outlet; 9-funnel-shaped structure; 10-vibrator; 11-base; 12-heater; 13-airflow multiplier; 14-catalyst inlet; 15-first preheater; 16-cyclone separator; 17-gas-liquid separation device; 18-olefin separation device; 19-heat exchanger; 20-second preheater; 21-catalyst regenerator; 22-catalyst feed pipeline; 23-reactor.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, but should not be understood as limiting the present disclosure.

Throughout the application, the disclosure of numerical ranges includes all values within the entire range and disclosure of further subdivided ranges, including endpoints and subranges given within those ranges.

In the application, the raw materials, equipment, etc. involved, unless otherwise specified, are all raw materials and equipment that can be produced through commercial channels or known methods; the methods involved, unless otherwise specified, are all conventional methods.

The following describes the CO2 hydrogenation to olefins reactor, the working method of the CO2 hydrogenation to olefins reactor, the CO2 hydrogenation to olefins system, and the working method of the CO2 hydrogenation to olefins system according to the embodiments of the present disclosure in conjunction with the accompanying drawings.

FIG1 is a schematic structural diagram of a carbon dioxide hydrogenation to olefins reactor according to an embodiment of the first aspect of the present disclosure.

As shown in FIG. 1 , the carbon dioxide hydrogenation to olefins reactor according to an embodiment of the present disclosure includes an outer shell 1 and an inner shell 2 .

The outer shell 1 is used for synthesizing methanol by reacting carbon dioxide with hydrogen. The outer shell 1 has a catalyst inlet 14 for entering the catalyst and an external reaction heat extractor 7 for conducting the reaction heat in the outer shell 1 .

The inner shell 2 is used for synthesizing olefins by methanol dehydration reaction. The inner shell 2 is arranged in the outer shell 1, and the inner shell 2 has a heater 12 for heating the reaction material, an internal reaction heat extractor 5 for extracting the reaction heat in the inner shell 2, and a first inlet 3 and a first outlet 4 for the reaction material to circulate between the inner shell 2 and the outer shell 1; the first inlet 3 and the first outlet 4 are arranged opposite to each other, and the first inlet 3 is adjacent to and opposite to the catalyst inlet 14.

The carbon dioxide hydrogenation to olefins reactor of the embodiment of the present disclosure has an inner shell for synthesizing olefins and an outer shell for synthesizing methanol, and controls the olefin synthesis temperature by a heater and an inner reaction heat collector, and controls the methanol synthesis temperature by an outer reaction heat collector, and the reaction materials circulate between the inner shell and the outer shell to realize the step-by-step reaction, thereby solving the problems of low conversion rate selectivity of the original single reactor and complex and high cost of the dual reactor process, so that the carbon dioxide hydrogenation to olefins reactor of the embodiment of the present disclosure has high carbon dioxide conversion rate and olefin selectivity, simple overall structure, low equipment investment, and high comprehensive benefits.

It should be noted that in the embodiments of the present disclosure, the outer shell and the inner shell are not limited to be arranged in any manner, and can be arranged vertically, horizontally or inclined. Preferably, the outer shell and the inner shell are both arranged vertically, and the first inlet is located at the inner shell. The bottom, first outlet is located at the top of the inner shell (as shown in FIG. 1 ).

In some embodiments, the inner shell 2 includes a first part 201 and a second part 202 which are connected to each other, the first part 201 is provided with a first outlet 4, the second part 202 is provided with a first inlet 3, and the cross-sections of the first part 201 and the second part 202 along the direction from the first inlet 3 to the first outlet 4 are both isosceles trapezoidal, and the size of the end of the first part 201 provided with the first outlet 4 and the size of the end of the second part 202 provided with the first inlet 3 are both smaller than the size of the connecting point between the first part 201 and the second part 201.

In some embodiments, the cross section of the inner shell 2 along the direction perpendicular to the first inlet 3 to the first outlet 4 is in one of the shapes of a circle, a rectangle, a square, etc. That is, the cross section of the first portion 201 and the second portion 202 along the direction perpendicular to the first inlet 3 to the first outlet 4 is in one of the shapes of a circle, a rectangle, a square, etc.

It is understood that the shapes of the first part and the second part include but are not limited to hollow truncated cone, hollow prism and similar shapes. When it is a truncated cone, the size refers to the diameter or radius; when it is a prism, the size refers to the length and width, or the side length.

In some embodiments, the first part 201 and the second part 202 are both hollow frustum-shaped, the first part 201 is provided with a first outlet 4 at one end adjacent to the catalyst, the second part 202 is provided with a first inlet 3 at one end away from the first part, and the diameter of the first part 201 at one end adjacent to the second part 202 is larger than the diameter of the first part 201 at one end adjacent to the first part 201 with the first outlet 4, the diameter of the second part 202 at one end adjacent to the first part 201 is equivalent to the diameter of the first part 201 at one end adjacent to the second part 202, and the diameter of the second part 202 at one end adjacent to the first part 201 is larger than the diameter of the second part 202 at one end adjacent to the first part 201 with the first inlet 3.

In some embodiments, the connection method between the first part and the second part includes but is not limited to integral molding, welding, etc.

In some embodiments, a middle portion of a cross section of the outer shell 1 along a direction from the first inlet 3 to the first outlet 4 is rectangular.

In some embodiments, a cross section of the outer shell 1 along a direction perpendicular to the first inlet 3 to the first outlet 4 is circular.

It can be understood that the outer shell can be cylindrical or cylindrical-like in shape.

In some embodiments, the inner shell 2 and the outer shell 1 are arranged coaxially in the direction from the first inlet 3 to the first outlet 4. For example, when the first part 201 and the second part 202 of the inner shell 2 are both truncated cone-shaped and the outer shell is cylindrical, the two are coaxially arranged.

In some embodiments, a plurality of second inlets 6 for the raw gas carbon dioxide and hydrogen to enter the interior of the outer shell 1 are provided on the side wall of the outer shell 1. Preferably, the plurality of second inlets 6 are spaced apart and distributed on the outer shell 1 along the direction of the first inlet 3 and the first outlet 4, and two adjacent second inlets 6 are arranged relative to each other or staggered. Here, relative arrangement is, for example, left and right sides, etc.; staggered arrangement is, for example, two adjacent second inlets are arranged at a certain angle and are not in the same vertical plane and the same horizontal plane.

In some embodiments, when the outer shell 1 is cylindrical, multiple second inlets 6 for the raw gases carbon dioxide and hydrogen to enter the interior of the outer shell 1 are all opened along the tangent direction of the inner wall of the outer shell 1, and the multiple second inlets 6 are distributed on the outer shell 1 at intervals along the direction of the first inlet 3 and the first outlet 4, and the positions of two adjacent second inlets 6 are relatively or staggered.

In the embodiments of the present disclosure, the number of the second inlets 6 is at least 2, including but not limited to 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc.

In some embodiments, an external reaction heat collector 7 and a product outlet 8 are provided on one side of the outer shell 1 adjacent to the first outlet 4 .

In some embodiments, the outer shell 1 is provided with an ellipsoidal head adjacent to the first outlet, and an external reaction heat collector 7 is installed adjacent to the first outlet to remove the reaction heat; the product outlet 8 is provided at the center of the ellipsoidal head.

In some embodiments, the internal reaction heat exchanger 5 can be arranged on the inner surface of the inner shell 2; in other embodiments, the internal reaction heat exchanger 5 can be arranged on the outer surface of the inner shell 2; in still other embodiments, the internal reaction heat exchanger 5 can be arranged on both the inner surface and the outer surface of the inner shell. It should be noted that the larger the heat exchange area between the internal reaction heat exchanger and the inner shell, the more conducive it is to remove the heat released by the olefin synthesis process in the inner shell.

In some embodiments, both the internal reaction heat collector 5 and the external reaction heat collector 7 may adopt heat exchange coils, heat exchange plates, etc. When in use, a circulating cooling medium, such as cooling water, oil, etc., may be introduced therein. The cooling medium absorbs the heat released by the reaction and is discharged from the reactor, thereby achieving the purpose of removing the reaction heat from the reactor.

In some embodiments, the outer shell 1 has a funnel-shaped structure 9 at one end adjacent to the first inlet 3, and the side of the funnel-shaped structure 9 away from the first inlet 3 is a catalyst inlet 14; the funnel-shaped structure 9 is mounted on a base 11, and a vibrator 10 is mounted on the funnel-shaped structure 9 for loosening the catalyst deposited on the side wall of the funnel-shaped structure 9. Preferably, the vibrator 10 is mounted on the outer surface of the funnel-shaped structure (the surface adjacent to one side of the base).

In some embodiments, the funnel-shaped structure is a conical structure that is open on both sides and hollow, a hollow truncated cone structure, a hollow prism structure, etc., and the size (e.g., diameter, etc.) of the side adjacent to the first inlet 3 is larger than the size (e.g., diameter, etc.) of the side away from the first inlet 3.

The structure of the vibrator in the embodiment of the present disclosure is not limited, including but not limited to one of an air hammer vibration device, a pneumatic vibrator, an ultrasonic transducer, an electromagnetic vibrator, etc. The intermittent vibration of the vibrator can prevent the catalyst from accumulating on the side wall of the funnel structure and causing blockage.

In some embodiments, the heater 12 is installed in the inner shell 2 next to the first inlet 3, and an airflow multiplier 13 is installed at the first inlet 3 for sucking the catalyst from the catalyst inlet 14 into the inner shell. Preferably, the airflow multiplier 13 is installed between the first inlet 3 and the catalyst inlet 14, and there is a gap between the airflow multiplier 13 and the catalyst inlet 14. As a non-limiting example, the distance between the airflow multiplier 13 and the catalyst inlet 14 is not greater than 20% of the inner diameter of the outer shell, and not less than 10% of the inner diameter of the outer reactor. This ensures that the catalyst is efficiently sucked into the inner shell; if the distance is too large, the catalyst solids cannot be carried into the inner reactor by the airflow to form a cycle; if the distance is too small, the gap between the bottom slope of the outer shell (that is, the side wall of the funnel-shaped structure) and the inner shell is too small, causing the catalyst settled in the outer shell to be unable to slide to the lowest end, causing blockage and unable to form a cycle.

It should be noted that although the heater of the embodiment of the present disclosure can be used to heat the reaction materials entering the inner shell and increase the reaction temperature of the synthesized olefins in the inner shell, the reaction materials circulate between the inner shell and the outer shell during the reaction. The annular flow is equivalent to indirectly heating the material entering the outer shell, thereby increasing the reaction temperature of the synthetic methanol in the outer shell.

In some embodiments, the structure of the airflow multiplier is not limited, and includes but is not limited to a bladeless fan, an axial flow fan, etc., which can suck the catalyst entering from the catalyst inlet and deposited on the side wall of the funnel-shaped structure (when the outer shell is vertically arranged, that is, the bottom of the outer shell) into the inner shell to participate in the reaction.

In some embodiments, the heater 12 includes but is not limited to one of an electric heater, a steam heater, a gas heater, and the like.

In some embodiments, the plurality of second inlets 6, the product outlet 8, the catalyst inlet 14, the inlets and outlets of the internal reaction heat collector 5 and the external reaction heat collector 7 are all provided with flow controllers for adjusting the flow rate.

In some embodiments, in order to monitor the reaction temperature and reaction pressure in real time, temperature measuring devices such as temperature sensors and pressure testing devices such as pressure sensors are installed on both the inner shell 2 and the outer shell 1 .

In some embodiments, in order to preheat the raw gas, a heating unit can also be set on the outer side wall of the outer shell. The heating unit includes but is not limited to a heat exchange jacket, an electric heater, etc. When a heat exchange jacket is used, hot water, hot flue gas, etc. can be introduced into the jacket.

The working method of the carbon dioxide hydrogenation to olefins reactor of the second embodiment of the present disclosure includes the following steps S1 to S4.

S1. Raw gas carbon dioxide and hydrogen are synthesized into methanol in the outer shell 1 under the action of the catalyst.

In some embodiments, when the outer shell is cylindrical and the size of the inner shell gradually decreases from the side adjacent to the first inlet to the side away from the first inlet (that is, the cross-section of the inner shell is a structure with one end larger than the other end), the working method of the embodiment of the present disclosure also includes the step of introducing raw gas carbon dioxide and hydrogen into the outer shell 1 along the tangential direction of the inner side of the outer shell 1 from multiple second inlets 6 to form a spiral airflow with the catalyst in the outer shell 1 and synthesize methanol.

Specifically, the raw gas is introduced into the outer shell through multiple second inlets along the inner tangential direction of the outer shell, providing power for the gas in the reactor. Driven by the raw gas flow, the raw gas and the catalyst form a spiral airflow in the outer shell, which reduces the falling speed of the catalyst, prolongs the residence time of the catalyst, and improves the single-pass reaction efficiency. Since the cross-section of the inner shell is large at one end and small at the other end, the flow area gradually decreases and the gas flow rate gradually increases when the gas flows in the outer shell. Therefore, the airflow and the catalyst will maintain a spiral state and react to synthesize methanol. The gas and the catalyst will eventually converge at the bottom of the outer shell and be sent into the inner shell together with the catalyst entering from the catalyst inlet to participate in the subsequent olefin synthesis.

In some embodiments, the mixing volume ratio of hydrogen and carbon dioxide in the raw gas is (2-4):1, including but not limited to 2:1, 3:1, 4:1 or 2.5:1, etc.

In some embodiments, the temperature of synthesizing methanol in the outer shell 1 is 200-300°C, including but not limited to 200°C, 225°C, 250°C, 275°C or 300°C.

In some embodiments, the pressure of the synthesized methanol in the outer shell 1 is 0.5-8 MPa, including but not limited to 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa or 8 MPa.

In some embodiments, the catalyst is a carbon dioxide hydrogenation to olefins catalyst, including but not limited to metal oxides such as Cu-Zn-Al, Zn-Zr, In ₂ O ₃ for the methanol route and bifunctional catalysts coupled with molecular sieves such as SAPO-34 and SAPO-18.

It should be noted that in the embodiments of the present disclosure, since the reaction materials circulate between the inner shell and the outer shell, the catalyst for synthesizing methanol in the outer shell and the catalyst for synthesizing olefins in the inner shell are the same catalyst, that is, the above catalyst entering the reactor from the catalyst inlet.

In some embodiments, the catalyst is carried by a carrier gas from the catalyst inlet 14 into the outer shell 1, and the carrier includes but is not limited to at least one of carbon dioxide, hydrogen, and an inert gas, wherein the inert gas includes but is not limited to at least one of nitrogen, helium, argon, etc.

S2. Driven by the raw gas, methanol and the catalyst are heated and enter the inner shell 2 from the first inlet 3 to synthesize olefins to form a mixed gas carrying the catalyst.

In some embodiments, the olefin is a low-carbon olefin, including but not limited to at least one of ethylene, propylene, butene, and the like.

In some embodiments, the temperature of the synthesized olefin in the inner shell 2 is 300-400°C, including but not limited to 300°C, 325°C, 350°C, 375°C or 400°C.

In some embodiments, the pressure of the synthetic olefin in the inner shell 2 is 0.5-8 MPa, including but not limited to 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa or 8 MPa.

In some embodiments, the working method of the embodiment of the present disclosure further includes the step of vibrating the catalyst deposited on the side wall of the funnel structure by the vibrator 10 to loosen the catalyst.

In some embodiments, the working method of the disclosed embodiment further includes the step of delivering the raw gas and the catalyst into the inner shell 2 via the gas flow multiplier 13 .

In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide and unreacted hydrogen.

It should be noted that in the embodiments of the present disclosure, since _CO2 and _H2 will generate CO by-product under the action of the methanol production catalyst, the mixed gas carrying the catalyst produced by the reaction should contain CO; and since CO and _H2 can also further react to generate methanol under the action of the catalyst of the embodiments of the present disclosure, there is no need to separate CO separately in the subsequent separation step.

It should be noted that the selection of the catalyst in step S2 and the method of entering the catalyst inlet (carried by the carrier gas) are similar to those in step S1 and will not be described in detail here.

S3. The mixed gas carrying the catalyst obtained in step S2 enters the outer shell 1 from the first outlet 4, and then part of it is discharged from the outer shell 1, and the other part forms a reaction material circulation between the outer shell 1 and the inner shell 2 after cooling.

In some embodiments, the volume ratio of the mixed gas discharged from the outer shell to the mixed gas circulating between the outer shell and the inner shell after cooling is 2-20:1, including but not limited to 2:1, 5:1, 10:1, 15:1 or 20:1. The volume ratio of the mixed gas in the shell to the mixed gas circulating between the outer shell and the inner shell after cooling is within the above range, which can ensure a higher yield and lower production cost per unit volume of the reactor; if it is greater than 20:1, it will lead to a lower yield; if it is less than 2:1, the subsequent separation load will be too large and the cost will increase.

S4. During the working process, the temperature of the synthesized methanol and the temperature of the synthesized olefin are controlled respectively by the external reaction heat collector 7 and the internal reactor heat collector.

In the embodiments of the present disclosure, the temperature of the synthesized methanol and the temperature of the synthesized olefins are controlled respectively by the external reaction heat collector 7 and the internal reactor heat collector, mainly by timely extracting the heat released by the synthesized methanol and the synthesized olefins through heat exchange to ensure the stability of the methanol synthesis temperature and the olefin synthesis temperature.

It should be noted that in the above step S4, the step of controlling the temperature of the synthesized methanol through the external reaction heat exchanger 7 can be performed simultaneously with step S1, and the step of controlling the temperature of the synthesized olefin through the internal reactor heat exchanger can be performed simultaneously with step S2, and the entire step S4 can be performed simultaneously with step S3.

In addition, it should be noted that in the embodiments of the present disclosure, the time for methanol synthesis and the time for olefin synthesis are usually measured by the contact time between the reactants and the catalyst (i.e., the space velocity). However, since the reaction materials circulate between the inner shell and the outer shell in the embodiments of the present disclosure, the methanol synthesis time and the olefin synthesis time can be measured by one reaction time. Since the final product is olefin, the reaction time can be uniformly named as olefin synthesis reaction time.

In some embodiments, the olefin synthesis reaction time of the disclosed embodiments is measured by space velocity, which is 1800-36000 L/kg catalyst/h, including but not limited to 1800 L/kg catalyst/h, 5000 L/kg catalyst/h, 10000 L/kg catalyst/h, 15000 L/kg catalyst/h, 20000 L/kg catalyst/h, 25000 L/kg catalyst/h, 30000 L/kg catalyst/h or 36000 L/kg catalyst/h, etc.

FIG2 is a schematic structural diagram of a carbon dioxide hydrogenation system for producing olefins according to an embodiment of the third aspect of the present disclosure.

As shown in FIG. 2 , the carbon dioxide hydrogenation to olefins system according to an embodiment of the present disclosure includes a reactor 23 , a cyclone separator 16 and an olefin separation device 18 .

The reactor 23 is a carbon dioxide hydrogenation to olefins reactor according to an embodiment of the present disclosure, and the feed gas inlet of the reactor 23 (i.e., the plurality of second inlets 6) is connected to the first preheater 15. It should be noted that the plurality of second inlets 6 can be connected to a first preheater 15 respectively, or can be connected to a first preheater 15 together.

The inlet of the cyclone separator 16 is connected to the product outlet 8 of the reactor 23, the gas outlet of the cyclone separator 16 is connected to the gas-liquid separation device 17, and the solid outlet of the cyclone separator 16 is sequentially connected to the catalyst regenerator 21 and the catalyst feed pipeline 22. The catalyst feed pipeline is used to feed the catalyst carried by the carrier gas into the reactor through the catalyst inlet.

The inlet of the olefin separation device 18 is connected to the gas outlet of the gas-liquid separation device 17, and the impurity outlet of the olefin separation device 18 is connected to the cold side of the heat exchanger 19, the second preheater 20 and the catalyst feed pipeline 22 in sequence. The hot side of the heat exchanger 19 is connected to the internal reaction heat extractor 5, and the catalyst feed pipeline 22 is connected to the catalyst inlet 14.

In some embodiments, the gas-liquid separation device 17 includes but is not limited to a gas-liquid separator, a condenser, a condensation tower, etc. A sort of.

In some embodiments, the gas-liquid separation device 17 is a gas-liquid separator, which condenses high-boiling-point water and methanol and separates them from other gases by cooling.

In some embodiments, the olefin separation device 18 includes, but is not limited to, a distillation tower, a pressure swing adsorption separation device, and the like.

In some embodiments, the olefin separation device 18 uses a distillation tower. Reactants and olefins can be separated at different positions of the distillation tower, and further purification of the olefins requires coordinated distillation of multiple towers.

In some embodiments, the catalyst regenerator 21 includes, but is not limited to, one of a regeneration tower, a regenerator, and the like.

In some embodiments, the catalyst regenerator 21 is a regeneration tower. The catalyst is moved from top to bottom, and the air is moved from bottom to top to react at high temperature to remove the carbon deposits formed on the catalyst surface.

In some embodiments, a portion of the catalyst to be regenerated is discharged during the catalyst regeneration process of the catalyst regenerator (catalyst discharge in Figure 2). The catalyst is kept sufficiently active by continuously discharging a portion of the old catalyst and adding new catalyst, because even if the catalyst can be regenerated, the performance will still decline after multiple cycles.

In some embodiments, the first preheater 15 and the second preheater 20 may be one of, including but not limited to, an air preheater, a tubular heat exchanger, a plate heat exchanger, and the like.

The working method of the carbon dioxide hydrogenation to olefins system of the fourth embodiment of the present disclosure includes the following steps S101 to S103.

S101, raw gas carbon dioxide and hydrogen enter the reactor and synthesize olefins under the action of the catalyst.

In some embodiments, the method for synthesizing olefins after the raw gas carbon dioxide and hydrogen enter the reactor under the action of a catalyst comprises the following steps:

(1) introducing the preheated raw gas carbon dioxide and hydrogen into the outer shell;

(2) turning on the airflow multiplier to establish circulation of the raw gas airflow between the inner shell and the outer shell;

(3) turning on the heater to heat the temperature of the inner shell adjacent to the first inlet to a methanol-to-olefins temperature, thereby promoting the conversion of methanol into olefins in the inner shell;

(4) Turn on the internal reaction heat collector and the external reaction heat collector to maintain the temperature of each area in the reactor stable;

(5) opening the product outlet and the catalyst inlet to establish a stable circulation between the reactor and the rest of the CO2 hydrogenation to olefins system;

(6) Carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of the catalyst, and methanol is synthesized into olefins in the inner shell under the action of the catalyst.

In some embodiments, in step (1), the raw gases carbon dioxide and hydrogen are preheated by a first preheater.

It should be noted that the above steps (1) to (5) are steps for preparing olefins in the startup phase of the olefin synthesis system of the carbon dioxide hydrogenation to olefins embodiment of the present disclosure. In the startup phase, there is no catalyst at the beginning, and the reactor and external system need to be (The rest of the CO2 hydrogenation system) The catalyst is added when the circulation is established. Initially, no reaction occurs inside the reactor, only the circulation is established, and the reaction gradually begins with the addition of the catalyst.

After the CO2 hydrogenation to olefins system operates smoothly (after a stable circulation is established between the reactor and the rest of the CO2 hydrogenation to olefins system), the other operations of step S101 (specifically, the process of synthesizing olefins in step (6)) are basically the same as the working method of the above-mentioned CO2 hydrogenation to olefins reactor, and will not be repeated here.

S102, part of the mixed gas carrying the catalyst discharged from the inner shell 2 is discharged from the outer shell 1, and then separated and treated by the cyclone separator 16. The catalyst obtained by the separation treatment is regenerated and returned to the reactor. The gas phase obtained by the separation treatment is successively treated by the gas-liquid separation device 17 and the olefin separation device 18 to obtain olefin products and unreacted raw gas.

In some embodiments, the mixed gas composition includes: olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide, and unreacted hydrogen.

In the embodiments of the present disclosure, the purpose of separation treatment by a cyclone separator is to separate catalyst particles from the mixed gas; the catalyst obtained by separation treatment by a cyclone separator enters a catalyst regenerator for regeneration to remove carbon deposits, and at the same time, the catalyst with a smaller particle size is discharged, and the remaining regenerated catalyst that meets the particle size requirements is introduced into the reactor together with the fresh catalyst through the catalyst inlet.

In the embodiments of the present disclosure, the gas phase obtained by the cyclone separator separation treatment is separated into water and a small amount of methanol (liquid) by a gas-liquid separation device, and the gas phase containing olefins enters an olefin separation device to separate and refine olefin products.

S103, the unreacted raw gas is heated by the heat medium from the internal reactor heat collector, and then preheated to be used as catalyst carrier gas.

The preheating in step S103 is performed by using a second preheater.

Certain features of the present technology are further illustrated in the following non-limiting examples.

Example 1

As shown in FIG1 , the CO2 hydrogenation to olefins reactor of this embodiment is a cyclone double-shell _CO2 hydrogenation to olefins reactor, which is suitable for a two-step _CO2 hydrogenation to olefins reaction. The CO2 hydrogenation to olefins reactor comprises an outer shell 1 and an inner shell 2.

The outer shell 1 is used for the reaction of carbon dioxide and hydrogen to synthesize methanol. The outer shell 1 is cylindrical and vertically arranged; the top of the outer shell 1 is an ellipsoidal head, and a material outlet 8 is arranged in the center of the ellipsoidal head. An external reaction heat collector 7 for conducting the heat release and cooling of the reaction in the outer shell 1 is installed on the ellipsoidal head. The external reaction heat collector 7 is located in the outer shell 1. The external reaction heat collector 7 is a heat exchange coil, and circulating cooling water is passed inside. The bottom of the outer shell 1 is a conical head (i.e., a funnel-shaped structure) with a large top and a small bottom. A catalyst inlet 14 is arranged at the bottom of the conical head. The conical head is installed on the base 11, which is used to realize the fixation of the base 11 to the entire carbon dioxide hydrogenation to olefins reactor. The shape of the side of the base 11 that contacts the conical head is equivalent to that of the conical head, and the outer surface of the conical head located on one side of the base 11 is installed with a vibrator 10 for loosening the catalyst deposited at the bottom. The vibrator 10 is a commercially available air hammer.

Two second inlets 6 for the raw gas carbon dioxide and hydrogen to enter are provided on the side wall of the outer shell 1, and the two second inlets 6 are respectively arranged on the left and right sides of the outer shell 1, and the two second inlets 6 are arranged at a certain interval up and down, but are both located between the material outlet 8 and the catalyst inlet 14; the two second inlets 6 are open along the tangent direction of the inner wall of the outer shell 1.

The inner shell 2 is used for synthesizing olefins by methanol dehydration reaction. The inner shell 2 is arranged in the outer shell 1 and is coaxially arranged with the outer shell 1. The inner shell 2 includes a first part 201 and a second part 202 which are connected to each other as a whole (the connection method can be, for example, integral molding, etc.), the first part 201 is located above the second part 202, and the two are connected. The first part 201 and the second part 202 are both truncated cones with a trapezoidal longitudinal section, the top diameter of the first part 201 is larger than the bottom diameter of the first part 201, the top diameter of the second part 202 is equivalent to the bottom diameter of the first part 201, and the top diameter of the second part 202 is larger than the bottom diameter of the second part 202.

The top of the first part is provided with a first outlet 4 for the reaction materials in the inner shell 2 to be discharged; the bottom of the second part is provided with a first inlet 3 for the reaction materials to enter the inner shell 1, and the first inlet 3 is adjacent to the catalyst inlet 14, and the two are arranged oppositely. The arrangement of the first inlet 3 and the first outlet 4 can realize the circulation of the reaction materials between the inner shell 2 and the outer shell 1. The airflow multiplier 13 is installed at the first inlet 3, which is a bladeless fan. The airflow multiplier 13 is located directly above the catalyst inlet 14, and there is a spacing between the two that is not more than 20% of the inner diameter of the outer shell and not less than 10% of the inner diameter of the outer shell (in some embodiments, 15% of the inner diameter of the outer shell). The airflow multiplier 13 is a bladeless fan that can suck the catalyst that enters from the catalyst inlet and is deposited on the bottom of the outer shell (the side wall of the conical head) into the inner shell to participate in the olefin synthesis reaction. The inner surface and the outer surface of the first part are both installed with an internal reaction heat collector 5 for extracting the reaction heat in the inner shell 2. For the convenience of description, the internal reaction heat collector 5 located on the outer surface of the first part can be marked as a first sub-heat collector 501, and the internal reaction heat collector 5 located on the inner surface of the first part can be marked as a second sub-heat collector 502. The first sub-heat collector 501 and the second sub-heat collector 502 are interconnected heat exchange coils, and circulating cooling water is passed through the inside to remove the reaction heat released by the olefin synthesis process in the inner shell 2 through heat exchange.

A heater 12 is installed on the inner wall of the second part to heat the reaction materials and increase the reaction temperature. The heater 12 is an electric heater.

The two second inlets 6, the product outlet 8, the catalyst inlet 14, the inlet and outlet of the internal reaction heat collector 5, the inlet and outlet of the external reaction heat collector 7, etc. are all provided with flow controllers for adjusting the flow.

In order to monitor the reaction temperature and reaction pressure in real time, temperature sensors, pressure sensors, etc. are installed on both the inner shell 2 and the outer shell 1 .

The working method of the carbon dioxide hydrogenation to olefins reactor of the present embodiment is as follows: the raw gas carbon dioxide and hydrogen are introduced into the outer shell 1 along the tangential direction of the inner side of the outer shell 1 through two second inlets 6 (each second inlet 6 introduces carbon dioxide and hydrogen), providing power for the gas in the entire reactor. Driven by the raw gas flow, the raw gas and the catalyst form a spiral airflow in the outer shell 1, which reduces the falling speed of the catalyst, prolongs the residence time of the catalyst, and improves the single-pass reaction efficiency. Since the cross-section of the first part of the inner shell 2 is in a shape of small at the top and large at the bottom, the gas in the outer shell 1 flows from top to bottom. During circulation, the circulation area gradually decreases and the gas flow rate gradually increases, so the gas flow and the catalyst will maintain a spiral flow and react to synthesize methanol. The gas and the catalyst will eventually converge at the bottom of the outer shell 1 and be sent to the inner shell 2 through the first inlet 3 together with the catalyst entering through the catalyst inlet 14; the gas and the catalyst in the inner shell 2 flow from bottom to top and react to synthesize olefins, and are finally discharged from the first outlet 4 at the top of the inner shell 2. Part of the discharged mixed gas (the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide and unreacted hydrogen) and the catalyst are discharged from the product outlet 9 to the outside of the outer shell 1, and the remaining mixed gas and the catalyst are cooled by the external reaction heat collector 7 and flow downward along the outer shell 1 to form a cycle.

During operation, the mixing volume ratio of hydrogen and carbon dioxide in the raw gas is (2-3): 1; the catalyst is a CO ₂ hydrogenation catalyst, such as a bifunctional catalyst of metal oxides such as Cu-Zn-Al, Zn-Zr, In ₂ O ₃ and molecular sieves such as SAPO-34 and SAPO-18 coupled in the methanol pathway; the temperature of synthesizing methanol in the outer shell 1 is 200-300°C, the temperature of synthesizing olefins in the inner shell 2 is 300-400°C, and the reaction pressure of synthesizing olefins is 0.5-5MPa. The vibrator 10 can intermittently knock on the bottom of the outer shell to prevent the catalyst from accumulating on the inclined surface of the conical head and causing blockage.

Example 2

As shown in FIG. 2 , the carbon dioxide hydrogenation to olefins system of this embodiment includes a reactor 23 , a cyclone separator 16 and an olefin separation device 18 .

The reactor 23 is the carbon dioxide hydrogenation to olefins reactor of Example 1. The two feed gas inlets of the reactor 23 (ie, the two second inlets 6 of Example 1) are both connected to a first preheater 15 .

The inlet of the cyclone separator 16 is connected to the product outlet 8 of the reactor 23, the gas outlet of the cyclone separator 16 is connected to the gas-liquid separation device 17, and the solid outlet of the cyclone separator 16 is sequentially connected to the catalyst regenerator 21 and the catalyst feed pipeline 22. The catalyst feed pipeline is used to feed the catalyst carried by the carrier gas into the reactor through the catalyst inlet.

The inlet of the olefin separation device 18 is connected to the gas outlet of the gas-liquid separation device 17, and the impurity outlet of the olefin separation device 18 is connected to the cold side of the heat exchanger 19, the second preheater 20 and the catalyst feed pipeline 22 in sequence; the hot side of the heat exchanger 19 is connected to the internal reaction heat extractor 5 to achieve preheating utilization. The catalyst feed pipeline 22 is connected to the catalyst inlet 14.

The gas-liquid separation device 17 is a gas-liquid separator, the olefin separation device 18 is a distillation tower, and the catalyst regenerator 21 is a regeneration tower; the first preheater 15 and the second preheater 20 are both air preheaters.

The working method of the carbon dioxide hydrogenation to olefin system of the present embodiment is as follows: the raw gas carbon dioxide and hydrogen preheated by the first preheater 15 enter the outer shell 1, and the _CO2 hydrogenation to methanol reaction occurs in the outer shell 1, and the reaction temperature is 200-300°C. Since the reaction is an exothermic reaction, an external reaction heat collector 7 is required to maintain temperature balance. The gas and the catalyst react when they flow downward in a spiral to generate methanol. There is an airflow multiplier 13 at the bottom between the outer shell 1 and the inner shell 2, which can send the gas, catalyst and the gas and catalyst introduced by the catalyst inlet 14 collected at the bottom into the inner shell 2; since the inner shell 2 is a methanol to olefin reaction, the reaction temperature is 300-400°C, which is higher than the outer shell 1, so a heater 12 is added at the bottom of the inner shell 2 to quickly heat the reaction materials, and the gas and catalyst flow from bottom to top in the inner shell 2. And react to generate olefins. Since this reaction is also an exothermic reaction, an internal reaction heat collector 5 is required to maintain a stable reaction temperature. The mixed gas carrying the catalyst (the mixed gas contains olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide and unreacted hydrogen) discharged from the inner shell 2 is partially discharged from the outer shell 1 through the product outlet 8. The mixed gas is first separated from the catalyst particles by a cyclone separator 16. The separated catalyst particles are first regenerated by a catalyst regenerator 21 to remove carbon deposits, and the catalyst with a smaller particle size is discharged. Finally, it is introduced into the reactor together with the fresh catalyst through the catalyst inlet 14. The gas after cyclone separation then enters the gas-liquid separation device 17 to separate water and a small amount of methanol, and then passes through the olefin separation device 18 to separate and refine the olefin product. The remaining unreacted raw gas is heated by the heat exchanger 19 and the second preheater 20, and then carries the catalyst to enter the reactor through the catalyst inlet 14.

Example 3

The carbon dioxide hydrogenation to olefins system of Example 2 is used to synthesize olefins, which specifically includes the following steps: first, a feed gas with a volume ratio of _H2 : _CO2 of 3:1 is preheated to 250°C, pressurized to 3MPa, and introduced into the outer shell 1 through the upper and lower feed gas inlets (i.e., the two second inlets 6); then the gas flow multiplier 13 is turned on to establish a circulation of the fluid (feed gas) in the inner shell 2 and the outer shell 1; then the heater 12 is turned on to heat the bottom temperature of the inner shell 2 to 380°C to promote the methanol-to-olefin reaction; then the inner reaction heat collector 5 and the outer reaction heat collector 7 are turned on to maintain the temperature of each region of the reactor stable; then the top product outlet 8 and the bottom catalyst inlet 14 are opened to establish a stable circulation between the reactor and the external system (cyclone separator, gas-liquid separation device, olefin separation device, heat exchanger, second preheater, catalyst regenerator, etc. in the carbon dioxide hydrogenation to olefins system). Finally, in the outer shell 1 of the reactor, the raw gas is catalyzed by the catalyst CuZnAl-SAPO-34 to produce methanol by _CO2 hydrogenation reaction to generate methanol and water. The temperature of the synthesized methanol is controlled by the external reaction heat collector 7 during the reaction process. The methanol in the inner shell 1 of the reactor is dehydrated to synthesize low-carbon olefins (C2 to C4 olefins) under the action of the catalyst CuZnAl-SAPO-34. During the synthesis process, the temperature of olefin synthesis is controlled by the internal reaction heat collector 5. The space velocity of the entire olefin synthesis reaction process is 12000L/kg catalyst/h. The reaction results are shown in Table 1.

During the olefin synthesis process of this embodiment, cyclone separation, gas-liquid separation, olefin separation, catalyst regeneration, etc. are all conventional operation processes, and the specific details are not repeated here.

Example 4

This embodiment is basically the same as Embodiment 3, except that:

The raw gas with a volume ratio of H ₂ :CO ₂ of 3:1 was preheated to 300° C.; the catalyst was ZnZrO-SAPO-34 catalyst.

Comparative Example 1

This comparative example is substantially the same as Example 3, except that:

The reactor in the carbon oxide hydrogenation to olefins system uses a traditional fluidized bed reactor. In the method for synthesizing olefins: the raw gas has a volume ratio of _H2 : _CO2 of 3:1, the reaction temperature is 380°C, the pressure is 3MPa, and a CuZnAl-SAPO-34 catalyst is used. The raw material undergoes a two-stage reaction in one reactor, and the space velocity is 12000L/kg catalyst/h. The reaction results are shown in Table 1.

Comparative Example 2

This comparative example is substantially the same as Example 3, except that:

The reactor in the carbon oxide hydrogenation to olefin system uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins: the volume ratio of the first-stage raw material _H2 : _CO2 is 3:1, the reaction temperature is 250°C, the pressure is 3MPa, and a CuZnAl catalyst is used. The reaction product is passed into the second-stage reactor. The reaction temperature of the second-stage reactor is 380°C, the pressure is 3MPa, and a SAPO-34 catalyst is used. The space velocity is 12000L/kg catalyst/h. The reaction results of the second-stage reactor are shown in Table 1.

Comparative Example 3

This comparative example is substantially the same as Example 3, except that:

The reactor in the carbon oxide hydrogenation to olefins system uses a traditional fluidized bed reactor. In the method for synthesizing olefins: the raw gas has a volume ratio of _H2 : _CO2 of 3:1, the reaction temperature is 380°C, the pressure is 3MPa, and a ZnZrO-SAPO-34 catalyst is used. The raw material undergoes a two-stage reaction in one reactor, and the space velocity is 12000L/kg catalyst/h. The reaction results are shown in Table 1.

Comparative Example 4

This comparative example is substantially the same as Example 3, except that:

The reactor in the carbon oxide hydrogenation to olefin system uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins: the volume ratio of the first-stage raw material _H2 : _CO2 is 3:1, the reaction temperature is 250°C, the pressure is 3MPa, and a ZnO- _ZrO2 catalyst is used. The reaction product is passed into the second-stage reactor. The reaction temperature of the second-stage reactor is 380°C, the pressure is 3MPa, and a SAPO-34 catalyst is used. The space velocity is 12000L/kg catalyst/h. The reaction results of the second-stage reactor are shown in Table 1.

Table 1 Reaction results of Examples 3-4 and Comparative Examples 1-4

Note: The “low-carbon olefins” in Table 1 refer to olefins of C2 to C4.

According to Table 1:

Comparison of Example 3 and Example 4 shows that, under the same other reaction conditions, different catalysts In the present invention, the carbon dioxide hydrogenation to olefins system is used to synthesize olefins, and the carbon dioxide conversion rate and olefin selectivity are basically equivalent.

It can be seen from Comparative Example 3 and Comparative Example 1 that, under completely identical reaction conditions, a higher carbon oxide conversion rate and olefin selectivity can be obtained by synthesizing olefins using a single reactor of the carbon dioxide hydrogenation to olefins system of the embodiment of the present disclosure.

By comparing Example 3 and Comparative Example 2, it can be seen that, under exactly the same reaction conditions, the single reactor of the carbon dioxide hydrogenation to olefins system of the embodiment of the present disclosure can be used to synthesize olefins, which can obtain a carbon oxide conversion rate and olefin selectivity that are basically equivalent to those of a two-stage fluidized bed reactor. However, since the reactor of Example 3 of the present disclosure is a single reactor, its structure is simpler than the two-stage fluidized bed reactor of Comparative Example 2, and only the temperature of the methanol synthesis olefin needs to be controlled, so the cost is lower and the operation is more convenient.

It can be seen from Comparative Examples 4 and 3 that, under substantially the same reaction conditions, a higher carbon oxide conversion rate and olefin selectivity can be obtained by synthesizing olefins using a single reactor of the carbon dioxide hydrogenation to olefins system of the disclosed embodiment.

By comparing Example 4 and Comparative Example 4, it can be seen that, when other reaction conditions are substantially the same, a single reactor of the carbon dioxide hydrogenation system of the embodiment of the present disclosure is used to synthesize olefins and a ZnZrO-SAPO-34 catalyst is used, and a higher carbon dioxide conversion rate can be obtained. In addition, since the reactor of Example 4 of the present disclosure is a single reactor, its structure is simpler than that of the two-stage fluidized bed reactor of Comparative Example 4, and only the temperature of methanol synthesis of olefins needs to be controlled, so the cost is lower and the operation is more convenient.

In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

In the present disclosure, unless otherwise expressly specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrated; they can be mechanically connected, electrically connected, or able to communicate with each other; they can be directly connected, or indirectly connected through an intermediate medium. The term "connected" may refer to the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

In the present disclosure, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

In the present disclosure, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims (13)

A carbon dioxide hydrogenation to olefins reactor, comprising: An outer shell, the outer shell is used for synthesizing methanol by reacting carbon dioxide and hydrogen, the outer shell having a catalyst inlet for entering the catalyst and an external reaction heat extractor for extracting the reaction heat in the outer shell; An inner shell, the inner shell is used for synthesizing olefins by dehydration reaction of methanol; the inner shell is arranged in the outer shell, and the inner shell has a heater for heating reaction materials, an internal reaction heat extractor for extracting reaction heat in the inner shell, and a first inlet and a first outlet for the reaction materials to circulate between the inner shell and the outer shell; the first inlet and the first outlet are arranged opposite to each other, and the first inlet is adjacent to and opposite to the catalyst inlet. The carbon dioxide hydrogenation to olefins reactor according to claim 1, wherein the inner shell comprises a first part and a second part that are interconnected, the first part is provided with the first outlet, the second part is provided with a first inlet, the cross-sections of the first part and the second part along the direction from the first inlet to the first outlet are both isosceles trapezoidal, and the size of the first part at one end where the first outlet is provided and the size of the second part at one end where the first inlet is provided are both smaller than the size of the connection point between the first part and the second part. The carbon dioxide hydrogenation to olefins reactor according to claim 1 or 2, wherein the inner shell and the outer shell are arranged along a common center line in a direction from the first inlet to the first outlet; And/or, a middle portion of a cross section of the outer shell along a direction from the first inlet to the first outlet is rectangular. The carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 3, wherein the outer shell is cylindrical, and a plurality of second inlets for the raw gas carbon dioxide and hydrogen to enter the interior of the outer shell are provided on the side wall of the outer shell, and the plurality of second inlets are opened along the tangent direction of the inner wall of the outer shell. The carbon dioxide hydrogenation to olefins reactor according to claim 4, wherein a plurality of the second inlets are distributed on the outer shell at intervals along the direction of the first inlet and the first outlet, and two adjacent second inlets are arranged relative to or staggered. The carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 5, wherein the internal reaction heat extractor is arranged on the inner surface and/or outer surface of the inner shell; And/or, the external reaction heat collector and the product outlet are provided on a side of the outer shell adjacent to the first outlet. The carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 6, wherein the heater is installed in the inner shell next to the first inlet, and an airflow multiplier for sucking the catalyst from the catalyst inlet into the inner shell is installed at the first inlet. The carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 7, wherein the outer shell is in a funnel-shaped structure at one end adjacent to the first inlet, and the side of the funnel-shaped structure away from the first inlet is the catalyst inlet; the funnel-shaped structure is mounted on a base, and a device for loosening the catalyst deposited on the funnel-shaped structure is installed on the funnel-shaped structure. Vibrators for the catalyst on the side walls of the funnel-shaped structure. A method for operating a carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 8, comprising: Raw gas carbon dioxide and hydrogen are used to synthesize methanol in the outer shell under the action of the catalyst; Driven by the raw gas, methanol and the catalyst are heated and enter the inner shell from the first inlet to synthesize olefins to form a mixed gas carrying the catalyst; The mixed gas enters the outer shell from the first outlet, and then a part of it is discharged from the outer shell, and the other part is cooled to form a reaction material circulation between the outer shell and the inner shell; The temperature of the synthetic methanol and the temperature of the synthetic olefin are controlled respectively via the external reaction heat collector and the internal reactor heat collector. The working method according to claim 9, wherein the working method further comprises the step of introducing raw gas carbon dioxide and hydrogen into the outer shell from a plurality of second inlets along the inner tangential direction of the outer shell to form a spiral gas flow with the catalyst in the outer shell to synthesize methanol; And/or, the working method further comprises the step of loosening the catalyst deposited on the side wall of the funnel structure by vibrating with a vibrator; And/or, the working method further comprises the step of delivering the raw gas and the catalyst into the inner shell through the gas flow multiplier; And/or, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide and unreacted hydrogen; And/or, in the raw gas, the mixing volume ratio of hydrogen and carbon dioxide is (2-4):1; and/or, the temperature of the synthetic methanol in the outer shell is 200-300° C. and the pressure is 0.5-8 MPa; and/or, the temperature of the synthesized olefin in the inner shell is 300-400° C. and the pressure is 0.5-8 MPa; And/or, the catalyst is a carbon dioxide hydrogenation to olefins catalyst; And/or, the catalyst is carried by a carrier gas from the catalyst inlet into the outer shell, and the carrier gas is at least one of carbon dioxide, hydrogen, and an inert gas. A carbon dioxide hydrogenation system for producing olefins, comprising: The reactor is a carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 8, wherein the feed gas inlet of the reactor is connected to a first preheater; A cyclone separator, wherein the inlet of the cyclone separator is connected to the product outlet of the reactor, the gas outlet of the cyclone separator is connected to the gas-liquid separation device, and the solid outlet of the cyclone separator is connected to the catalyst regenerator and the catalyst feed pipeline in sequence; An olefin separation device, wherein the inlet of the olefin separation device is connected to the gas outlet of the gas-liquid separation device, The impurity outlet of the hydrocarbon separation device is connected to the cold side of the heat exchanger, the second preheater and the catalyst feed pipeline in sequence, the hot side of the heat exchanger is connected to the internal reaction heat extractor, and the catalyst feed pipeline is connected to the catalyst inlet. A method for operating a carbon dioxide hydrogenation to olefins system as claimed in claim 11, comprising: After the raw gas carbon dioxide and hydrogen enter the reactor, olefins are synthesized under the action of the catalyst; The mixed gas carrying the catalyst discharged from the inner shell is partially discharged from the outer shell, and then separated and treated by a cyclone separator. The catalyst obtained by the separation treatment is regenerated and reused in the reactor. The gas phase obtained by the separation treatment is sequentially treated by a gas-liquid separation device and an olefin separation device to obtain olefin products and the unreacted raw gas. The unreacted raw gas is heated by the heat medium from the internal reactor heat collector and then preheated to be used as catalyst carrier gas. The working method according to claim 12, wherein the method of synthesizing olefins under the action of a catalyst after the raw gas carbon dioxide and hydrogen enter the reactor comprises: introducing the preheated raw gas carbon dioxide and hydrogen into the outer shell; Turning on the airflow multiplier to establish circulation of the raw gas airflows between the inner shell and the outer shell; Turning on the heater to heat the temperature of the inner shell adjacent to the first inlet to a methanol-to-olefins temperature, thereby promoting the conversion of methanol into olefins in the inner shell; Turning on the internal reaction heat collector and the external reaction heat collector to maintain the temperature of each area in the reactor stable; Opening the product outlet and the catalyst inlet to establish a stable circulation between the reactor and the rest of the carbon dioxide hydrogenation to olefins system; The carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of the catalyst, and the methanol is synthesized into olefins in the inner shell under the action of the catalyst.