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

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] 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

[0003] 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, a working method thereof, and applications thereof. Background Art

[0004] Climate change is a major challenge facing the world and a major global issue that profoundly affects the economic and social development and ecological environment of all countries. Research by the International Energy Agency (IEA) shows that to achieve the Paris Agreement goal of limiting the global average temperature rise to below 2°C above pre-industrial levels, CCUS will contribute between 10% and 20% when all emission reduction technologies are optimally configured. This means that without CCUS technology, the goal of limiting the temperature rise to 2°C will not be achieved. Carbon dioxide utilization technology is an important means of achieving carbon neutrality. CO2 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 of reducing CO2 emissions from high cost to low cost, or even negative cost.

[0005] Chemical utilization of CO2 can produce a variety of products, including synthesis gas, natural gas, formic acid, methanol, olefins, gasoline, carbonates, and urea. Olefins are important basic organic chemical raw materials, particularly low-carbon olefins such as ethylene and propylene, which are the most widely used and serve as the basis for the three major synthetic materials (plastics, rubber, and fiber). Ethylene and propylene are the world's most valuable chemical products, and olefin production technology and production capacity are key indicators of a country's petrochemical industry development.

[0006] Currently, research on catalysts for CO2 hydrogenation to olefins has made significant progress. A relatively mature synthesis method is a two-step reaction via the methanol pathway. However, the reaction conditions for these two steps often differ significantly, making it difficult to achieve optimal conditions for each step using a single conventional reactor. This results in low overall conversion and selectivity. Using two separate reactors for each reaction complicates the process and increases initial investment.

[0007] 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.

[0008] Summary of the Invention

[0009] The first embodiment of the present disclosure provides a carbon dioxide hydrogenation to olefins reactor, comprising:

[0010] An outer shell, the outer shell being used for reacting carbon dioxide and hydrogen to synthesize methanol, the outer shell having a catalyst inlet for entering the catalyst and an external reaction heat extractor for discharging reaction heat within the outer shell;

[0011] 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 the reaction materials, an internal reaction heat extractor for extracting the 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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 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 tangential direction of the inner wall of the outer shell.

[0016] In some embodiments, a plurality of second inlets are spaced apart and distributed on the outer shell along the direction between the first inlet and the first outlet, and two adjacent second inlets are positioned opposite to each other or staggered.

[0017] In some embodiments, the internal reaction heat collector is provided on the inner surface and / or outer surface of the inner shell.

[0018] 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.

[0019] In some embodiments, the heater is installed in the inner shell adjacent to one side of the first inlet, and an airflow multiplier is installed at the first inlet for drawing the catalyst from the catalyst inlet into the inner shell.

[0020] 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 for loosening the catalyst deposited on the side wall of the funnel-shaped structure.

[0021] A second embodiment of the present disclosure provides a method for operating a carbon dioxide hydrogenation to olefins reactor according to any one of the first embodiments, including:

[0022] Raw gas carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of catalyst;

[0023] Driven by the raw gas, methanol and catalyst are heated and then enter the inner shell from the first inlet to synthesize olefins to form a mixed gas carrying the catalyst;

[0024] The mixed gas enters the outer shell from the first outlet, and then partially exits the outer shell, and the remaining part forms a reaction material circulation between the outer shell and the inner shell after cooling;

[0025] The temperature of the synthetic methanol and the temperature of the synthetic olefin are controlled respectively via the external reaction heat exchanger and the internal reactor heat exchanger.

[0026] 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.

[0027] In some embodiments, the working method further comprises the step of vibrating with a vibrator to loosen the catalyst deposited on the sidewall of the funnel structure.

[0028] In some embodiments, the working method further includes the step of delivering the raw gas and catalyst into the inner shell through the airflow multiplier.

[0029] In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0030] In some embodiments, the mixing volume ratio of hydrogen and carbon dioxide in the raw gas is (2-4):1.

[0031] 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.

[0032] 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.

[0033] In some embodiments, the catalyst is a carbon dioxide hydrogenation to olefins catalyst.

[0034] 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.

[0035] The third embodiment of the present disclosure provides a carbon dioxide hydrogenation system for producing olefins, comprising:

[0036] A reactor, wherein the reactor is the carbon dioxide hydrogenation to olefins reactor according to any embodiment of the first aspect of the present disclosure, wherein the feed gas inlet of the reactor is connected to a first preheater;

[0037] 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 line in sequence;

[0038] 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.

[0039] The fourth embodiment of the present disclosure provides a method for operating the carbon dioxide hydrogenation to olefins system of any embodiment of the third aspect, including:

[0040] After the raw gases carbon dioxide and hydrogen enter the reactor, they synthesize olefins under the action of the catalyst;

[0041] 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 then 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.

[0042] The unreacted raw gas is heated by the heat medium from the internal reactor heat exchanger and then preheated to be used as catalyst carrier gas.

[0043] In some embodiments, the method for synthesizing olefins in the presence of a catalyst after the raw gases carbon dioxide and hydrogen enter a reactor comprises:

[0044] introducing the preheated raw gas carbon dioxide and hydrogen into the outer shell;

[0045] Turning on the airflow multiplier to establish circulation of the raw gas airflow between the inner shell and the outer shell;

[0046] 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;

[0047] Turning on the internal reaction heat exchanger and the external reaction heat exchanger to maintain stable temperatures in various regions within the reactor;

[0048] opening a product outlet and a catalyst inlet to establish a stable circulation between the reactor and the rest of the carbon dioxide hydrogenation to olefins system;

[0049] 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.

[0050] The carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment has at least the following beneficial effects:

[0051] 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, and realize the simultaneous occurrence of two-step CO2 hydrogenation to olefins reaction. 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.

[0052] 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 will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0054] FIG1 is a schematic structural diagram of a carbon dioxide hydrogenation to olefins reactor according to an embodiment of the present disclosure.

[0055] FIG2 is a schematic structural diagram of a carbon dioxide hydrogenation system for producing olefins according to an embodiment of the present disclosure.

[0056] Figure markings: 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

[0057] The 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 intended to be used to explain the present disclosure, but should not be understood as limiting the present disclosure.

[0058] Throughout this application, the disclosure of numerical ranges includes disclosure of all values ​​within the entire range and further subdivided ranges, including endpoints and subranges given within those ranges.

[0059] 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.

[0060] The following describes the CO2 hydrogenation to olefins reactor, the operating method of the CO2 hydrogenation to olefins reactor, the CO2 hydrogenation to olefins system, and the operating method of the CO2 hydrogenation to olefins system according to the embodiments of the present disclosure with reference to the accompanying drawings.

[0061] 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.

[0062] As shown in FIG1 , 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 .

[0063] The outer shell 1 is used for synthesizing methanol by reacting carbon dioxide and hydrogen. The outer shell 1 has a catalyst inlet 14 for entering the catalyst and an external reaction heat extractor 7 for discharging the reaction heat in the outer shell 1 .

[0064] Inner housing 2 is used for methanol dehydration reaction to synthesize olefins. It is located within outer housing 1 and includes a heater 12 for heating the reaction materials, an internal reaction heat extractor 5 for dissipating the reaction heat within inner housing 2, and a first inlet 3 and a first outlet 4 for circulating the reaction materials between inner housing 2 and outer housing 1. The first inlet 3 and first outlet 4 are positioned opposite each other, and the first inlet 3 is adjacent to and opposite the catalyst inlet 14.

[0065] The carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment comprises an inner shell for synthesizing olefins and an outer shell for synthesizing methanol. The olefin synthesis temperature is controlled by a heater and an inner reaction heat exchanger, and the methanol synthesis temperature is controlled by an outer reaction heat exchanger. The reaction materials circulate between the inner shell and the outer shell to achieve a step-by-step reaction. This solves the problems of low conversion rate and selectivity of the original single reactor and complex and high cost of the dual-reactor process. The carbon dioxide hydrogenation to olefins reactor of the disclosed embodiment has a high carbon dioxide conversion rate and olefin selectivity, a simple overall structure, low equipment investment, and high overall benefits.

[0066] It should be noted that in the embodiments of the present disclosure, the outer shell and the inner shell are not limited to being arranged in any manner and can be arranged vertically, horizontally, or inclined. Preferably, the outer shell and the inner shell are both arranged vertically, in which case the first inlet is located at the bottom of the inner shell and the first outlet is located at the top of the inner shell (as shown in FIG1 ).

[0067] In some embodiments, the inner shell 2 includes a first part 201 and a second part 202 that are connected to each other, the first part 201 is provided with a first outlet 4, and the second part 202 is provided with a first inlet 3. 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 with the first outlet 4 and the size of the end of the second part 202 with the first inlet 3 are both smaller than the size of the connection point between the first part 201 and the second part 201.

[0068] In some embodiments, the cross-section of the inner housing 2 along the direction perpendicular to the first inlet 3 to the first outlet 4 is in one of the following shapes: circular, rectangular, square, etc. In other words, 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 following shapes: circular, rectangular, square, etc.

[0069] It is understood that the shapes of the first and second parts include, but are not limited to, hollow truncated cones, hollow prisms, and similar shapes. When the shape is truncated cone, the dimensions refer to the diameter or radius; when the shape is prisms, the dimensions refer to the length and width, or the side length.

[0070] 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 the end adjacent to the second part 202 is larger than the diameter of the first part 201 at the end with the first outlet 4, the diameter of the second part 202 at the end adjacent to the first part 201 is equivalent to the diameter of the first part 201 at the end adjacent to the second part 202, and the diameter of the second part 202 at the end adjacent to the first part 201 is larger than the diameter of the second part 202 at the end with the first inlet 3.

[0071] In some embodiments, the connection method between the first part and the second part includes but is not limited to integral molding, welding, etc.

[0072] 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.

[0073] 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.

[0074] It can be understood that the outer shell can be cylindrical or cylindrical-like in shape.

[0075] 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 portion 201 and the second portion 202 of the inner shell 2 are both truncated cone-shaped and the outer shell is cylindrical, the two are coaxially arranged.

[0076] In some embodiments, the sidewall of the outer shell 1 is provided with a plurality of second inlets 6 for the raw carbon dioxide and hydrogen gases to enter the interior of the outer shell 1. Preferably, the plurality of second inlets 6 are spaced apart on the outer shell 1 along the direction between the first inlet 3 and the first outlet 4, with adjacent second inlets 6 positioned opposite each other or staggered. Here, opposite arrangement includes, for example, left and right sides; staggered arrangement includes, for example, two adjacent second inlets being arranged at a certain angle and not in the same vertical or horizontal plane.

[0077] 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 tangential 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 relative or staggered.

[0078] In the embodiment 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.

[0079] In some embodiments, an external reaction heat collector 7 and a product outlet 8 are provided on a side of the outer shell 1 adjacent to the first outlet 4 .

[0080] 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.

[0081] In some embodiments, the internal reaction heat exchanger 5 can be located on the inner surface of the inner shell 2; in other embodiments, the internal reaction heat exchanger 5 can be located on the outer surface of the inner shell 2; in still other embodiments, the internal reaction heat exchanger 5 can be located on both the inner and outer surfaces 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 removing the heat released during the olefin synthesis process within the inner shell.

[0082] In some embodiments, both the internal reaction heat collector 5 and the external reaction heat collector 7 can adopt heat exchange coils, heat exchange plates, etc. When in use, a circulating cooling medium, such as cooling water, oil, etc., can be introduced into them. 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.

[0083] In some embodiments, the outer shell 1 has a funnel-shaped structure 9 at one end proximate to the first inlet 3, and a catalyst inlet 14 is formed at the side of the funnel-shaped structure 9 away from the first inlet 3. 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 catalyst deposited on the sidewall of the funnel-shaped structure 9. Preferably, the vibrator 10 is mounted on the outer surface of the funnel-shaped structure (the surface proximate to the base).

[0084] 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 (for example, diameter, etc.) of the side adjacent to the first inlet 3 is larger than the size (for example, diameter, etc.) of the side away from the first inlet 3.

[0085] The vibrator structure 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.

[0086] In some embodiments, the heater 12 is installed in the inner shell 2 on the side close to the first inlet 3, and an airflow multiplier 13 is installed on the first inlet 3 to suck 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 distance 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 will not be carried by the airflow into the inner reactor 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 will be 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.

[0087] It should be noted that although the heater in the embodiment of the present disclosure can be used to heat the reaction materials entering the inner shell and increase the reaction temperature of synthesizing olefins in the inner shell, since the reaction materials circulate between the inner shell and the outer shell during the reaction process, it is equivalent to indirectly heating the materials entering the outer shell, thereby increasing the reaction temperature of synthesizing methanol in the outer shell.

[0088] In some embodiments, the structure of the airflow multiplier is not limited, and includes but is not limited to bladeless fans, axial flow fans, 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.

[0089] 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.

[0090] 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 exchanger 5 and the external reaction heat exchanger 7 are all provided with flow controllers for regulating flow rates.

[0091] 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 .

[0092] 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.

[0093] The operating method of the carbon dioxide hydrogenation to olefins reactor according to the second embodiment of the present disclosure includes the following steps S1 to S4.

[0094] S1, raw gas carbon dioxide and hydrogen are synthesized into methanol in the outer shell 1 under the action of the catalyst.

[0095] 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 and the other end smaller), the working method of the embodiment of the present disclosure also includes the step of introducing the 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.

[0096] 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. The spiral airflow will reduce the falling speed of the catalyst, prolong the residence time of the catalyst, and improve 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 through 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 the catalyst inlet to participate in the subsequent olefin synthesis.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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, In2O3 in the methanol pathway and bifunctional catalysts coupled with molecular sieves such as SAPO-34 and SAPO-18.

[0101] 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-mentioned catalyst entering the reactor through the catalyst inlet.

[0102] In some embodiments, the catalyst is carried by a carrier gas from the catalyst inlet 14 into the outer shell 1, and the carrier gas 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.

[0103] 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, forming a mixed gas carrying the catalyst.

[0104] 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.

[0105] 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.

[0106] In some embodiments, the pressure of the synthesized 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.

[0107] In some embodiments, the working method of the embodiment of the present disclosure further includes a step of vibrating the catalyst deposited on the side wall of the funnel structure by the vibrator 10 to loosen the catalyst.

[0108] In some embodiments, the working method of the embodiment of the present disclosure further includes the step of sending the raw gas and the catalyst into the inner shell 2 through the airflow multiplier 13.

[0109] In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0110] 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 steps.

[0111] It should be noted that the selection of the catalyst in step S2 and the manner 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.

[0112] S3. The mixed gas carrying the catalyst obtained in step S2 enters the outer shell 1 from the first outlet 4, and then partially discharges from the outer shell 1, while the other part forms a reaction material circulation between the outer shell 1 and the inner shell 2 after cooling.

[0113] In some embodiments, the volume ratio of the mixed gas exiting 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. A volume ratio of the mixed gas exiting the outer shell to the mixed gas circulating between the outer shell and the inner shell after cooling within this range can ensure a high yield and low production cost per unit volume of the reactor. A ratio greater than 20:1 can result in a decrease in yield; a ratio less than 2:1 can result in an excessive load on subsequent separations and increased costs.

[0114] 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 exchanger 7 and the internal reactor heat exchanger.

[0115] In the embodiment 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.

[0116] 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 carried out simultaneously with step S1, and the step of controlling the temperature of the synthesized olefin through the internal reactor heat exchanger can be carried out simultaneously with step S2. The entire step S4 can be carried out simultaneously with step S3.

[0117] 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 generally measured by the time the reactants are in contact with the catalyst (i.e., the space velocity). However, since the reactants 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, this reaction time can be uniformly named as the olefin synthesis reaction time.

[0118] 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.

[0119] 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.

[0120] As shown in FIG2 , 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 .

[0121] Reactor 23 is a CO2 hydrogenation to olefins reactor according to an embodiment of the present disclosure. The feed gas inlet of 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 each be connected to a first preheater 15, or can be connected to a single first preheater 15.

[0122] The inlet of cyclone separator 16 is connected to product outlet 8 of reactor 23, the gas outlet of cyclone separator 16 is connected to gas-liquid separator 17, and the solid outlet of cyclone separator 16 is connected in sequence to catalyst regenerator 21 and catalyst feed line 22. The catalyst feed line is used to deliver catalyst carried by carrier gas into the reactor through the catalyst inlet.

[0123] The inlet of the olefin separation unit 18 is connected to the gas outlet of the gas-liquid separation unit 17, and the impurity outlet of the olefin separation unit 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.

[0124] In some embodiments, the gas-liquid separation device 17 includes but is not limited to one of a gas-liquid separator, a condenser, a condensation tower, and the like.

[0125] In some embodiments, the gas-liquid separation device 17 is a gas-liquid separator that condenses high-boiling-point water and methanol and separates them from other gases by cooling.

[0126] 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.

[0127] In some embodiments, the olefin separation unit 18 uses a distillation column. Reactants and olefins can be separated at different locations in the distillation column. Further purification of the olefins requires coordinated distillation in multiple columns.

[0128] In some embodiments, the catalyst regenerator 21 includes, but is not limited to, a regeneration tower, a regenerator, and the like.

[0129] In some embodiments, the catalyst regenerator 21 is a regeneration tower. The catalyst flows downwards while the air flows upwards at high temperature to remove the carbon deposits on the catalyst surface.

[0130] In some embodiments, a portion of the catalyst to be regenerated is discharged during the catalyst regeneration process (catalyst discharge in FIG2 ). Continuous discharge of a portion of the old catalyst and addition of new catalyst maintains sufficient catalyst activity, because even if the catalyst can be regenerated, its performance will still decline after multiple cycles.

[0131] In some embodiments, the first preheater 15 and the second preheater 20 may be one of, but not limited to, an air preheater, a tubular heat exchanger, a plate heat exchanger, and the like.

[0132] The operating method of the carbon dioxide hydrogenation to olefins system of the fourth embodiment of the present disclosure includes the following steps S101 to S103.

[0133] S101, raw gas carbon dioxide and hydrogen enter the reactor and synthesize olefins under the action of the catalyst.

[0134] In some embodiments, the method for synthesizing olefins in the presence of a catalyst after the raw gases carbon dioxide and hydrogen enter a reactor comprises the following steps:

[0135] (1) introducing the preheated raw gas carbon dioxide and hydrogen into the outer shell;

[0136] (2) turning on the airflow multiplier to establish circulation of the raw gas flow between the inner shell and the outer shell;

[0137] (3) turning on the heater to heat the inner shell to a temperature close to the first inlet to a methanol-to-olefins temperature, thereby promoting the conversion of methanol into olefins in the inner shell;

[0138] (4) Open the internal reaction heat exchanger and the external reaction heat exchanger to maintain the temperature of each area in the reactor stable;

[0139] (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;

[0140] (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.

[0141] In some embodiments, in step (1), the raw gases carbon dioxide and hydrogen are preheated by a first preheater.

[0142] It should be noted that steps (1) to (5) above are steps for preparing olefins during the startup phase of the CO2 hydrogenation to olefins system according to the disclosed embodiment. Initially, no catalyst is present during the startup phase. The catalyst is added only after the reactor and external system (the rest of the CO2 hydrogenation to olefins system) have established a circulation system. Initially, no reaction occurs within the reactor; only the circulation system is established. The reaction gradually begins with the addition of the catalyst.

[0143] 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.

[0144] S102, the mixed gas carrying the catalyst discharged from the inner shell 2 is partially 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 sequentially treated by the gas-liquid separation device 17 and the olefin separation device 18 to obtain olefin products and unreacted raw gas.

[0145] In some embodiments, the mixed gas comprises: olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0146] In the embodiments of the present disclosure, the purpose of separation treatment by a cyclone separator is to separate the catalyst particles in 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 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.

[0147] In the embodiment of the present disclosure, the gas phase obtained by the cyclone separator is separated into water and a small amount of methanol (liquid) by the gas-liquid separation device, and the gas phase containing olefins enters the olefin separation device to separate and refine the olefin products.

[0148] S103. The unreacted raw gas is heated by the heat medium from the internal reactor heat exchanger and then preheated to be used as catalyst carrier gas.

[0149] The preheating in step S103 is performed using a second preheater.

[0150] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0151] Example 1

[0152] As shown in Figure 1, the CO2 hydrogenation to olefins reactor of this embodiment is a cyclone-type double-shell CO2 hydrogenation to olefins reactor 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.

[0153] The outer shell 1 is used to react 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 with a material outlet 8 in the center. The ellipsoidal head is equipped with an external reaction heat collector 7 for conducting heat released by the reaction in the outer shell 1 and cooling the temperature. The external reaction heat collector 7 is located inside the outer shell 1 and is a heat exchange coil with circulating cooling water inside. The bottom of the outer shell 1 is a conical head (i.e., a funnel-shaped structure) with a larger top and a smaller bottom. The bottom of the conical head is equipped with a catalyst inlet 14. The conical head is mounted on a base 11 to achieve 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 similar to that of the conical head, and the outer surface of the conical head on the side of the base 11 is equipped with a vibrator 10 for loosening the catalyst deposited on the bottom. The vibrator 10 is a commercially available air hammer.

[0154] 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 provided on the left and right sides of the outer shell 1. The two second inlets 6 are provided at a certain interval above and below, but are both located between the material outlet 8 and the catalyst inlet 14; the two second inlets 6 are opened along the tangential direction of the inner wall of the outer shell 1.

[0155] The inner housing 2 is used for the dehydration reaction of methanol to synthesize olefins. The inner housing 2 is disposed within the outer housing 1 and is coaxially arranged with the outer housing 1. The inner housing 2 comprises a first portion 201 and a second portion 202, which are integrally connected (e.g., the connection can be integrally formed). The first portion 201 is positioned above the second portion 202, and the two portions are connected. The first portion 201 and the second portion 202 are both truncated cones with a trapezoidal longitudinal cross-section. The top diameter of the first portion 201 is larger than the bottom diameter of the first portion 201, the top diameter of the second portion 202 is comparable to the bottom diameter of the first portion 201, and the top diameter of the second portion 202 is larger than the bottom diameter of the second portion 202.

[0156] The top of the first section is provided with a first outlet 4 for discharging the reactants from the inner shell 2; the bottom of the second section is provided with a first inlet 3 for the reactants to enter the inner shell 1. The first inlet 3 is adjacent to the catalyst inlet 14 and the two are arranged opposite each other. The arrangement of the first inlet 3 and the first outlet 4 allows the reactants to circulate between the inner shell 2 and the outer shell 1. A bladeless fan, airflow multiplier 13, is installed at the first inlet 3. Airflow multiplier 13 is located directly above the catalyst inlet 14, with a spacing of no more than 20% and no less than 10% (in some embodiments, 15%) of the inner diameter of the outer shell, between the two. Airflow multiplier 13 is a bladeless fan that draws catalyst that enters through the catalyst inlet and deposits on the bottom of the outer shell (the sidewall of the conical head) into the inner shell to participate in the olefin synthesis reaction. Internal reaction heat collectors 5 for removing reaction heat from inner shell 2 are mounted on both the inner and outer surfaces of the first section. For ease of description, the internal reaction heat collector 5 located on the outer surface of the first section can be labeled as first sub-heat collector 501, and the internal reaction heat collector 5 located on the inner surface of the first section can be labeled as second sub-heat collector 502. First sub-heat collector 501 and second sub-heat collector 502 are interconnected heat exchange coils with circulating cooling water flowing through them. They remove the reaction heat released during the olefin synthesis process within inner shell 2 through heat exchange.

[0157] A heater 12 is installed on the inner wall of the second part for heating the reaction materials to increase the reaction temperature. The heater 12 is an electric heater.

[0158] The two second inlets 6, the product outlet 8, the catalyst inlet 14, the inlet and outlet of the internal reaction heat exchanger 5, the inlet and outlet of the external reaction heat exchanger 7, etc. are all provided with flow controllers for regulating flow rates.

[0159] 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 .

[0160] The working method of the carbon dioxide hydrogenation reactor of this embodiment is as follows: the raw gas carbon dioxide and hydrogen are introduced into the outer shell 1 along the inner tangential direction of the outer shell 1 through two second inlets 6 (each second inlet 6 is introduced with 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. The spiral airflow will reduce the falling speed of the catalyst, prolong the residence time of the catalyst, and improve 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 flow area of ​​the gas in the outer shell 1 gradually decreases when it flows from top to bottom, and the gas flow rate gradually increases, so the airflow and the catalyst form a spiral airflow. The catalyst will maintain a spiral flow and react to synthesize methanol. The gas and catalyst will eventually converge at the bottom of the outer shell 1 and be sent into the inner shell 2 through the first inlet 3 together with the catalyst entering from the catalyst inlet 14. The gas and 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. The remaining mixed gas and catalyst are cooled by the external reaction heat collector 7 and flow downward along the outer shell 1 to form a cycle.

[0161] During operation, the volume ratio of hydrogen and carbon dioxide in the feed gas is (2-3):1. The catalyst is a CO2 hydrogenation to olefins catalyst, such as a bifunctional catalyst coupling metal oxides such as Cu-Zn-Al, Zn-Zr, or In2O3 in the methanol pathway with molecular sieves such as SAPO-34 and SAPO-18. The temperature for methanol synthesis in outer shell 1 is 200-300°C, while the temperature for olefin synthesis in inner shell 2 is 300-400°C. The reaction pressure for olefin synthesis is 0.5-5 MPa. A vibrator 10 can intermittently strike the bottom of the outer shell to prevent catalyst accumulation on the inclined surface of the conical head, causing blockage.

[0162] Example 2

[0163] As shown in FIG2 , the carbon dioxide hydrogenation to olefins system of this embodiment includes a reactor 23 , a cyclone separator 16 and an olefin separation device 18 .

[0164] 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 .

[0165] The inlet of cyclone separator 16 is connected to product outlet 8 of reactor 23, the gas outlet of cyclone separator 16 is connected to gas-liquid separator 17, and the solid outlet of cyclone separator 16 is connected in sequence to catalyst regenerator 21 and catalyst feed line 22. The catalyst feed line is used to deliver catalyst carried by carrier gas into the reactor through the catalyst inlet.

[0166] The inlet of the olefin separation unit 18 is connected to the gas outlet of the gas-liquid separation unit 17. The impurity outlet of the olefin separation unit 18 is connected in sequence to the cold side of the heat exchanger 19, the second preheater 20, and the catalyst feed line 22. The hot side of the heat exchanger 19 is connected to the internal reaction heat extractor 5 for preheating. The catalyst feed line 22 is connected to the catalyst inlet 14.

[0167] 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.

[0168] The working method of the carbon dioxide hydrogenation to olefin system of this 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 extractor 7 is required to maintain temperature balance. The gas and the catalyst react when flowing downward in a spiral to generate methanol. An air flow multiplier 13 is provided at the bottom between the outer shell 1 and the inner shell 2, which can send the gas, catalyst and 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 to the bottom of the inner shell 2 to quickly heat the reaction materials. The gas and the catalyst flow from bottom to top in the inner shell 2 and react to generate olefins. It should also be an exothermic reaction, so it is necessary to use an internal reaction heat collector 5 to maintain a stable reaction temperature; the mixed gas carrying the catalyst discharged from the inner shell 2 (the mixed gas contains olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide and unreacted hydrogen) is partially discharged from the outer shell 1 through the product outlet 8. This part of 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 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 and enters the reactor through the catalyst inlet 14.

[0169] Example 3

[0170] The carbon dioxide hydrogenation to olefins system of Example 2 is used to synthesize olefins, specifically including the following steps: first, a feed gas with a volume ratio of H2:CO2 of 3:1 is preheated to 250°C, pressurized to 3 MPa, and introduced into the outer shell 1 through the upper and lower feed gas inlets (i.e., the two second inlets 6); then the air flow multiplier 13 is turned on to establish circulation of the fluid (feed gas) between 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 internal reaction heat exchanger 5 and the external reaction heat exchanger 7 are turned on to maintain the temperature of each area 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 feed gas is catalyzed by the CuZnAl-SAPO-34 catalyst to produce methanol by CO2 hydrogenation reaction, generating methanol and water. The temperature of the synthesized methanol is controlled by the external reaction heat exchanger 7 during the reaction process. In the inner shell 1 of the reactor, the methanol is dehydrated to synthesize light olefins (C2 to C4 olefins) under the action of the CuZnAl-SAPO-34 catalyst. The temperature of the olefin synthesis is controlled by the internal reaction heat exchanger 5 during the synthesis process. The space velocity of the entire olefin synthesis reaction process is 12000 L / kg catalyst / h. The reaction results are shown in Table 1.

[0171] During the olefin synthesis process of this embodiment, cyclone separation, gas-liquid separation, olefin separation, catalyst regeneration, etc. are all conventional operations, and the specific details are not repeated here.

[0172] Example 4

[0173] This embodiment is basically the same as embodiment 3, except that:

[0174] The raw gas with a volume ratio of H2:CO2 of 3:1 was preheated to 300°C; the catalyst was ZnZrO-SAPO-34 catalyst.

[0175] Comparative Example 1

[0176] This comparative example is basically the same as Example 3, except that:

[0177] The reactor in the carbon dioxide hydrogenation system to olefins uses a conventional fluidized bed reactor. In the olefin synthesis method, the raw gas has a volume ratio of H2:CO2 of 3:1, the reaction temperature is 380°C, the pressure is 3 MPa, and a CuZnAl-SAPO-34 catalyst is used. The raw material undergoes a two-stage reaction in one reactor at a space velocity of 12,000 L / kg catalyst / h. The reaction results are shown in Table 1.

[0178] Comparative Example 2

[0179] This comparative example is basically the same as Example 3, except that:

[0180] The reactor in the carbon dioxide hydrogenation system to produce olefins uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins, the volume ratio of H2:CO2 raw materials in the first stage is 3:1, the reaction temperature is 250°C, the pressure is 3 MPa, and a CuZnAl catalyst is used. The reaction product is passed into the second stage reactor. The reaction temperature in the second stage reactor is 380°C, the pressure is 3 MPa, and a SAPO-34 catalyst is used. The space velocity is 12,000 L / kg catalyst / h. The reaction results of the second stage reactor are shown in Table 1.

[0181] Comparative Example 3

[0182] This comparative example is basically the same as Example 3, except that:

[0183] The reactor in the carbon dioxide hydrogenation system to olefins uses a conventional fluidized bed reactor. In the olefin synthesis method, the feed gas has a volume ratio of H2:CO2 of 3:1, the reaction temperature is 380°C, the pressure is 3 MPa, and a ZnZrO-SAPO-34 catalyst is used. The feed gas undergoes a two-stage reaction in one reactor at a space velocity of 12,000 L / kg catalyst / h. The reaction results are shown in Table 1.

[0184] Comparative Example 4

[0185] This comparative example is basically the same as Example 3, except that:

[0186] The reactor in the carbon dioxide hydrogenation system to produce olefins uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins, the volume ratio of H2:CO2 raw materials in the first stage is 3:1, the reaction temperature is 250°C, the pressure is 3 MPa, and a ZnO-ZrO2 catalyst is used. The reaction product is passed into the second stage reactor. The reaction temperature in the second stage reactor is 380°C, the pressure is 3 MPa, and a SAPO-34 catalyst is used. The space velocity is 12,000 L / kg catalyst / h. The reaction results of the second stage reactor are shown in Table 1.

[0187] Table 1 Reaction results of Examples 3-4 and Comparative Examples 1-4

[0188] Note: “Light olefins” in Table 1 refer to C2 to C4 olefins.

[0189] According to Table 1:

[0190] By comparing Example 3 and Example 4, it can be seen that, under the premise that other reaction conditions are the same, the carbon dioxide conversion rate and olefin selectivity are basically equivalent when olefins are synthesized using the carbon dioxide hydrogenation to olefins system of the embodiment of the present disclosure under the action of different catalysts.

[0191] It can be seen from Comparative Example 3 and Comparative Example 1 that, under exactly 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 embodiment of the present disclosure.

[0192] 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 the 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 olefins needs to be controlled, so the cost is lower and the operation is more convenient.

[0193] It can be seen from Comparative Example 4 and Comparative Example 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.

[0194] Comparison of Example 4 and Comparative Example 4 shows that, with other reaction conditions essentially the same, a higher carbon dioxide conversion rate can be achieved by synthesizing olefins using a single reactor in the carbon dioxide hydrogenation to olefins system of the disclosed embodiment and employing a ZnZrO-SAPO-34 catalyst. Furthermore, because the reactor in Example 4 of the disclosed embodiment is a single reactor, it has a simpler structure than the two-stage fluidized bed reactor in Comparative Example 4, and only requires controlling the temperature of the methanol to olefin synthesis process, resulting in lower costs and more convenient operation.

[0195] 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0196] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0197] In this disclosure, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections or indirect connections through an intermediate medium; and internal communication between two elements or interaction between two elements, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0198] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it 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. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0199] In the present disclosure, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" 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 expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0200] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on 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

1. 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.

2. 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.

3. 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.

4. The CO2 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 CO2 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.

5. 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.

6. The carbon dioxide hydrogenation to olefins reactor according to any one of claims 1 to 5, wherein the internal reaction heat collector 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.

7. 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.

8. A 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 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.

9. 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.

10. 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 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.

11. A system for preparing olefins by hydrogenating carbon dioxide, 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 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 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.

12. A method for operating the 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.

13. The working method according to claim 12, wherein the method of 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.

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