Raw gas distributor, reactor and method for preparing gasoline by hydrogenating carbon dioxide

Abstract

This application discloses a feed gas distributor, a reactor containing the same, and a method for catalytic CO2 hydrogenation to gasoline. The feed gas distributor comprises a housing I, which encloses a cylindrical cavity; the housing is provided with multiple pore groups along the axial direction; each pore group contains multiple exhaust holes arranged circumferentially; the spacing between two adjacent pore groups is arranged axially from top to bottom according to a preset method I; and the apertures of the exhaust holes in two adjacent pore groups are also arranged axially from top to bottom according to a preset method II. This allows the feed gas to enter the reactor more rationally, preventing significant hot spots from occurring during the catalyst bed reaction. A reactor containing a feed gas distributor, a heat conduction device, and the feed gas distributor is also disclosed, for catalytic CO2 hydrogenation to gasoline. This ensures that the reaction heat is not only evenly distributed throughout the catalyst bed but also evenly removed, ensuring stable, safe, and efficient reaction.

Description

Technical Field

[0001] The present application relates to a raw gas distributor, a reactor containing the same and a method for catalytic CO2 hydrogenation to produce gasoline, belonging to the field of catalytic synthesis. Background Art

[0002] The conversion of carbon dioxide to gasoline, a key process in the conversion and utilization of carbon dioxide, not only contributes to CO2 emissions reduction and its effective resource utilization, but will also play a crucial role in future energy systems. However, due to the chemical inertness of CO2, unlike the hydrogenation of CO2 to low-carbon compounds such as methane and methanol, the hydrogenation of CO2 to high-carbon compounds such as gasoline is extremely challenging. The development of efficient catalyst systems and the design of rational reactors and process flows are currently key objectives in this process.

[0003] Research on the highly selective synthesis of gasoline hydrocarbons by CO2 hydrogenation can be divided into two categories: one is through the reaction of oxygenated intermediates such as methanol; the other is through reactions similar to the Fischer-Tropsch synthesis (FTS). Currently, most research focuses on FTS-like reaction pathways, where CO2 is first converted to CO via the reverse water-gas shift (RWGS) reaction, followed by CO hydrogenation and subsequent FTS reaction. Regardless of the pathway, the single-pass yield of CO2 needs to be further improved. Furthermore, research on the reaction apparatus and reactors for the CO2 hydrogenation to gasoline process is limited. Because the process is a rapidly exothermic reaction, maintaining uniform distribution of reaction heat across the catalyst bed and timely removal of reaction heat are also critical issues that need to be addressed for the process to be applied.

[0004] Patent CN110669543A relates to a device and method for directly producing gasoline by hydrogenating carbon dioxide. This device and method utilizes an indium oxide / molecular sieve (In2O3 / HZSM-5) bifunctional composite catalyst. A shell-and-tube synthesis reactor with an external circulating heat exchange mechanism is used as the reactor. The reactor outlet undergoes multi-stage cooling, dehydration by a molecular sieve adsorber, and, after gas-liquid separation, the gaseous components are partially recycled and partially discharged as purge gas to a flare system. The device's characteristics are well-suited to the In2O3 / HZSM-5-catalyzed carbon dioxide-to-gasoline reaction: low conversion, high gasoline product selectivity, and low product water content. However, it is less suitable for iron-based / molecular sieve (Na-Fe3O4 / HZSM-5) multifunctional composite catalysts, which exhibit high conversion, high gasoline product selectivity, and high product water content. Therefore, it is necessary to develop a reaction system tailored to the characteristics of iron-based / molecular sieve multifunctional composite catalysts.

[0005] CN209465003U discloses a hydrogenation reactor device suitable for carbon dioxide hydrogenation reaction, comprising a tower shell, characterized in that the barrel of the tower shell is configured as a hollow cylindrical structure, and a discharge pipe is provided at the bottom of the tower shell. The invention can facilitate real-time monitoring of the reaction temperature and pressure within the tower shell according to different production conditions, facilitate adjustment of the reaction temperature and pressure within the tower shell, and regulate the hydrogenation reaction. By providing a first air blowing device, a second air blowing device, and an upper cooling device, the reaction temperature is effectively reduced. By providing an inlet diffuser, a distributor, a first porcelain ball layer, a second porcelain ball layer, a third porcelain ball layer, a fourth porcelain ball layer, a fifth porcelain ball layer, a sixth porcelain ball layer, a seventh porcelain ball layer, an eighth porcelain ball layer, and a redistributor, uniform liquid supply is achieved. By providing a light source, a photocatalytic reaction is achieved, thereby increasing the catalytic conversion efficiency. The patented reactor design is unsuitable for CO2 hydrogenation to gasoline systems using Na-Fe3O4 / HZSM-5 catalysts for the following reasons: CO2 hydrogenation to gasoline is a rapidly exothermic reaction, and most of the reaction heat comes from the iron-based catalyst bed. The iron-based catalyst bed has extremely uneven temperature distribution and is prone to temperature fluctuations, which can damage catalyst performance and pose safety issues. Using the reactor's quenching system to cool the reactor could cause the reaction to stop, resulting in discontinuous operation. Designing a reactor that ensures continuous and stable operation remains a challenge. Summary of the Invention

[0006] The current technical problem in the process of catalytic CO2 hydrogenation to gasoline is that the large heat released by the iron-based catalyst bed causes uneven temperature distribution in the catalyst bed and the appearance of large hot spots, which in turn causes the catalyst to react at an ineffective temperature. This not only leads to a significant reduction in the selectivity of the gasoline product in the catalytic reaction, but also seriously affects the stability of the catalytic reaction, resulting in catalyst deactivation.

[0007] To address the current issues of high heat release and uneven catalyst bed temperature distribution in the catalytic hydrogenation of CO2 to gasoline, this application provides a new reactor. The reactor comprises a cylindrical tubular shell, providing ample space for rapid reaction; multiple layers of porous baffles supporting multifunctional catalyst material, with different components of the diluted multifunctional catalyst filled between the baffles; heat dissipation pipes dispersed between the porous baffles to regulate and remove the uneven reaction heat generated between the baffles due to the different components of catalytic material; and a feed distributor for evenly distributing feedstock into the catalyst bed. The distribution of feedstock gas in the catalyst bed is regulated according to the needs of different sections, thereby promoting uniform temperature distribution in the reaction bed.

[0008] The reactor is suitable for the characteristics of the Na-Fe3O4 / HZSM-5 catalytic CO2 hydrogenation to gasoline reaction process. The reactor designed in this application has the advantages of high gasoline yield and continuous and stable operation.

[0009] According to one aspect of the present application, a raw gas distributor is provided. The raw gas distributor includes multiple outlet holes from the middle to the bottom. The outlet holes decrease in size as they approach the bottom, and the spacing between outlet holes in different layers gradually increases, thereby ensuring a uniform outlet velocity.

[0010] A raw gas distributor, comprising a shell I, wherein the shell I encloses a cylindrical cavity;

[0011] The shell is provided with a plurality of air hole groups along the axial direction;

[0012] Each of the air hole groups contains a plurality of exhaust air holes arranged along the circumferential direction;

[0013] The spacing between two adjacent pore groups is arranged axially from top to bottom according to the preset method I;

[0014] The apertures of the exhaust pores in two adjacent pore groups are also arranged axially from top to bottom according to the preset method II.

[0015] Optionally, the preset mode I is to increase gradually; or,

[0016] The preset method I is to gradually increase and then remain unchanged.

[0017] Optionally, the preset mode I is constant and then gradually increases; or,

[0018] The preset method I is to gradually increase, then remain unchanged, and then increase again.

[0019] Optionally, the preset mode II is to gradually decrease; or,

[0020] The preset method II is to gradually decrease and then remain unchanged.

[0021] Optionally, the preset mode II is unchanged and then gradually decreases; or,

[0022] The preset method II is to gradually decrease, then remain unchanged, and then decrease again.

[0023] Optionally, the distance between two adjacent pore groups is n, and the difference between adjacent distances is Δn;

[0024] The value range of Δn / n is:

[0025] 0≤Δn / n≤5.

[0026] Optionally, 0≤Δn / n≤3.

[0027] Optionally, 0.2≤Δn / n≤1.

[0028] Optionally, the air outlet holes in each row are staggered up and down.

[0029] As a preferred embodiment, the aperture size of the first exhaust hole and the second exhaust hole is 0.5 mm, and the spacing is 0.5 cm; the aperture size of the third exhaust hole and the fourth exhaust hole is 0.4 mm, and the spacing is 1.5 cm, and the spacing between the second row and the third exhaust hole is 1 cm; the aperture size of the fifth exhaust hole and the sixth exhaust hole is 0.3 mm, and the spacing is 2 cm, and the spacing between the fourth row and the fifth exhaust hole is 2 cm.

[0030] As a preferred embodiment, the aperture sizes of the first exhaust holes and the second exhaust holes are 0.7 mm and 0.5 mm respectively, and the spacing is 0.7 cm; the aperture sizes of the third exhaust holes and the fourth exhaust holes are both 0.4 mm, and the spacing is 1.5 cm, and the spacing between the second row and the third exhaust holes is 1.0 cm; the aperture sizes of the fourth exhaust holes are both 0.2 mm, and the spacing is 2.0 cm.

[0031] Optionally, the distance between the first exhaust hole and the top of the raw gas distributor is greater than or equal to one eighth of the total length of the raw gas distributor.

[0032] Optionally, the distance between the first exhaust hole and the top of the raw gas distributor is greater than or equal to half of the total length of the raw gas distributor.

[0033] In this application, there is no strict limitation on the length, inner diameter, and aperture of the gas outlet of the raw gas distributor. In actual use, corresponding matching selection can be made according to the specifications of the specifically selected reactor.

[0034] According to another aspect of the present application, a reactor for catalytic CO2 hydrogenation to gasoline is provided. This reactor incorporates a feedstock distributor and a heat pipe, with the outlet of the feedstock distributor located in the first bed of a multi-stage catalyst. This ensures that the reaction heat is not only evenly distributed across the catalyst bed but also uniformly removed, ensuring stable reaction performance.

[0035] A reactor for catalytic CO2 hydrogenation to gasoline, comprising a raw gas distributor, a shell II, and a porous partition;

[0036] The porous partition divides the shell II into the first reaction zone, the second reaction zone, and the outlet zone from top to bottom;

[0037] Catalyst I is placed in the first reaction zone, and catalyst II is placed in the second reaction zone;

[0038] The raw gas distributor is located in the first reaction zone and is in communication with the first reaction zone;

[0039] The raw gas distributor includes at least one of the raw gas distributors described above.

[0040] Optionally, the number of the raw gas distributors is 1 to 100, optimized to 1 to 50, and most preferably 1 to 10. If the reactor and the distributor are very different, more distributors may be installed. In extreme cases, the number may reach 100 or more. During application, the number can be adjusted accordingly based on the actual situation.

[0041] In the present application, different numbers of raw material distributors can be placed according to the diameter of the raw gas distributor and the diameter of the reactor. The raw gas distributor allows the raw gas to enter the reactor more rationally, while ensuring the performance of the catalytic reaction, and preventing the catalyst bed reaction from having obvious hot spots. In view of the reaction process and the catalyst used in the present invention, the outlet holes of the raw material distributor are mainly distributed in the upper space of a section of catalyst (i.e., iron-based catalyst) or the upper half of the catalyst bed.

[0042] In the present application, a raw material distributor is used to evenly distribute the raw materials into the catalyst bed, and the distribution of the raw material gas in the catalyst bed is regulated according to the requirements of different sections, thereby facilitating the even distribution of the reaction bed temperature.

[0043] Optionally, the first reaction zone is provided with a heat conducting device I;

[0044] The second reaction zone is provided with a heat conducting device II.

[0045] Optionally, the thermal conductivity of the heat-conducting medium of the heat-conducting device I is greater than the thermal conductivity of the heat-conducting medium of the heat-conducting device II.

[0046] Optionally, the heat conduction device is selected from at least one of a heat conduction pipe and a heat conduction plate.

[0047] In this application, the heat conducting device is used to quickly remove the reaction heat. The heat conducting device is installed in different catalyst beds, and according to the different heat release of the catalyst bed reaction, the heat conducting device with different heat conduction properties can be selected.

[0048] The heat conducting device dispersed in the reactor of the present application is used to regulate and remove the uneven reaction heat generated by catalytic materials of different components.

[0049] Optionally, the porous partition blocks the catalyst in the reaction zone and allows the gas after the reaction in the reaction zone to pass through.

[0050] Optionally, the porous separator is an inert porous material.

[0051] In this application, the porous partition serves to support the catalyst loaded into the reactor. The pore size and number of the porous partition must meet the requirements of both blocking the catalyst and ensuring uniform and unobstructed flow of the reactant gases. Therefore, provided these requirements are met, the more pores in the partition, the larger the pore size, and the more uniform the pore distribution, the more conducive it is to uniform and rapid gas flow.

[0052] Optionally, the first reaction zone and the second reaction zone are each independently provided with a plurality of porous sub-plates along the axial direction.

[0053] Optionally, the number of the porous sub-plates is k, where k is a positive integer from 1 to 8.

[0054] In the present application, different components of the diluted multifunctional catalyst are filled between different partitions. The catalyst in the first reaction zone is an iron-based catalyst, and the catalyst in the second reaction zone is an acidic molecular sieve catalyst.

[0055] Optionally, a gas distribution plate is provided at the inlet of the raw gas distributor.

[0056] In this application, the reactor utilizes a multi-stage catalyst loading system, taking into account the characteristics of the catalyst. The inlet stage uses Na-Fe₃O₄ catalyst, which requires dilution with an inert material, while the outlet stage uses HZSM-5 catalyst, which requires no dilution. This type of reactor loading, combined with a heat pipe and a raw material distributor, ensures uniform distribution of reaction heat and timely removal of excess reaction heat during the reactor reaction, thereby ensuring uniform temperature distribution in the catalyst bed, stable catalyst reaction performance, and safe reactor operation.

[0057] According to one aspect of the present application, a method for catalytically hydrogenating CO2 to produce gasoline is provided, using the reactor described above.

[0058] Optionally, the raw gas containing carbon dioxide and hydrogen enters the first reaction zone through a raw gas distributor, reacts to obtain logistics A, and logistics A enters the second reaction zone, reacts to obtain logistics B.

[0059] Optionally, the first reaction zone is filled with an iron-based catalyst to synthesize light olefins from the feed gas containing carbon dioxide and hydrogen;

[0060] The second stage reaction zone is filled with an acidic molecular sieve catalyst to convert light olefins into gasoline fraction hydrocarbons.

[0061] Optionally, the iron-based catalyst is selected from at least one of Na-Fe3O4, K-Fe3O4, and Na-Mn-Fe3O4.

[0062] Optionally, the acidic molecules are selected from at least one of HZSM-5, HZSM-22, HY, and HSAPO-5.

[0063] Optionally, the silicon-aluminum ratio of the acidic molecular sieve is 15-500.

[0064] In the present application, there is no strict limitation on the iron-based catalyst and the acidic molecular sieve catalyst, and a suitable catalyst can be selected from the prior art according to actual needs.

[0065] Optionally, the mass ratio of the iron-based catalyst to the molecular sieve catalyst is 1:3 to 3:1.

[0066] In this application, the catalyst is filled in multiple sections. The iron-based catalyst is filled in the raw gas inlet section and can be filled in one or multiple sections according to actual conditions; the molecular sieve catalyst is filled in the reactor raw gas outlet section and can be filled in one or multiple sections according to actual conditions.

[0067] Optionally, the stream A contains light olefins;

[0068] The stream B contains gasoline fraction hydrocarbons.

[0069] Optionally, the reaction heat of the raw gas containing carbon dioxide and hydrogen in the first reaction zone is discharged through the heat conducting device I;

[0070] The reaction heat of the logistics A in the second reaction zone is discharged through the heat conduction device II.

[0071] Optionally, the operating conditions of the reactor are: raw gas: H2 / CO2 volume ratio = 0.5 to 8, catalyst space velocity: 1000 to 10000 ml / (g·h), reaction temperature of 250 to 450°C, and pressure of 1.0 to 6.0 MPa.

[0072] Optionally, the operating conditions of the reactor are: raw gas: H2 / CO2=0.5~8, containing or not containing reaction gases such as CO, light hydrocarbons or inert gases such as N2, Ar, a catalyst space velocity of 1000~10000 ml / (g catalyst·hour), a reaction temperature of 250~450℃, and a pressure of 1.0~6.0MPa

[0073] Optionally, the method further comprises a catalyst reduction pretreatment step: passing a mixed gas containing reducing gas through an iron-based catalyst and an acidic molecular sieve catalyst; the reduction conditions are 280-500° C. for 3-15 hours.

[0074] Optionally, the reducing gas is selected from at least one of hydrogen and carbon monoxide.

[0075] Optionally, the raw gas containing carbon dioxide and hydrogen also includes a preheating process; the temperature after preheating is 230-350°C.

[0076] The present invention adopts a Na-Fe3O4 / HZSM-5 catalyst to catalyze the reaction of hydrogenating carbon dioxide to produce gasoline. The catalyst is filled in two sections. The catalyst in the inlet section (i.e., catalyst 1) is a Na-Fe3O4 catalyst. The process of hydrogenating carbon dioxide to produce light olefins via CO occurs on this catalyst, and the overall reaction in this section is a highly exothermic reaction. The catalyst in the outlet section (i.e., catalyst 2) is a modified HZSM-5 molecular sieve. The process of polymerizing, hydrogenating, isomerizing, and aromatizing intermediate light olefins to produce gasoline fraction hydrocarbons occurs on this catalyst, and the overall reaction in this section is a mildly exothermic reaction.

[0077] When loading catalyst into a conventional fixed reactor, the catalyst bed is prone to hot spots, a phenomenon known as bed temperature runaway. Previous tests by the inventors have shown that while the normal catalyst reaction temperature is 320°C, hot spots appear in the catalyst bed after the reaction, rapidly heating to over 500°C (within 2 hours). This not only prevents the reaction from proceeding, but also damages the catalyst structure, severely impacting the catalyst's performance. However, using the reactor designed in accordance with the present invention, the catalyst bed temperature is essentially controlled at around 320°C, with no significant hot spots exceeding 350°C. The reaction can operate stably for nearly a thousand hours.

[0078] The beneficial effects of this application include:

[0079] 1) The raw material distributor provided in this application can make the gas outlet velocity of the gas outlet holes uniform, so that the raw gas enters the reactor more reasonably, and prevents the catalyst bed reaction from having obvious hot spot temperatures while ensuring the catalytic reaction performance.

[0080] 2) The reactor provided in this application contains a raw material distributor, a heat conducting device and a raw material distributor, so that the reactor of the present invention operates more stably than a traditional fixed bed reactor, the catalyst bed temperature is evenly distributed, and the operating temperature is easy to control, ensuring that the reaction heat is not only evenly distributed in the catalyst bed, but also can be evenly removed, ensuring the stable progress of the reaction, safety and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 Schematic diagram of the raw gas distributor used in Example 1;

[0082] Figure 2 Schematic diagram of a reactor for hydrogenating carbon dioxide to produce gasoline.

[0083] List of parts and reference numerals:

[0084] In the figure, 1. Tubular shell 2. Porous partition I 3. Porous partition II

[0085] 4. Catalyst I 5. Catalyst II 6. Gas distribution plate

[0086] 7. Gas distributor 8. Heat pipe I 9. Heat pipe II

[0087] 10. Heat pipe I inlet 11. Heat pipe I outlet

[0088] 12. Heat pipe II inlet 13. Heat pipe II outlet

[0089] 14. Reactor outlet 15. Raw gas inlet pipe DETAILED DESCRIPTION

[0090] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0091] Unless otherwise specified, the raw materials and catalysts in the examples of this application were purchased from commercial sources. Unless otherwise specified, the test methods all adopted conventional methods, and the instrument settings all adopted the settings recommended by the manufacturer.

[0092] Among them, the iron-based catalyst is Na-Fe3O4, which comes from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences.

[0093] HZSM-5 was purchased from the catalyst plant of Nankai University, with a silicon-aluminum ratio of 25-400.

[0094] The conversion rate of reactant CO2 and the yield of gasoline product are calculated as follows:

[0095] CO2 conversion rate (%) = CO2 conversion mole number / CO2 feed mole number х100%

[0096] Gasoline product yield (mg 汽油 g catalyst -1 ·h -1 ) = raw material volume space velocity (mL·g catalyst -1 ·h -1 ) × CO2 volume percentage in the feed (%) × CO2 conversion rate (%) × gasoline product selectivity (%) / 22400 × gasoline molar mass (mg / mol)

[0097] Example 1

[0098] The raw gas distributor adopts Figure 1 The raw gas distributor shown in the figure uses Φ12 stainless steel pipe, with 8 holes in each row, a total of 6 rows of holes, each row is staggered up and down, the specific hole diameter and spacing are as follows Figure 1 In this embodiment, three raw gas distributors are placed.

[0099] The catalyst in the reactor is diluted and filled with multi-layer catalyst ceramic balls (the dilution ratio of iron-based catalyst to ceramic balls is 1:5, and the dilution ratio of molecular sieve catalyst to ceramic balls is 2:1). The iron-based catalyst is Na-Fe3O4, the dosage is 10g, the mass ratio of iron-based catalyst to acidic molecular sieve is 1:2, and the acidic molecular sieve is HZSM-5 (silicon-aluminum ratio is 180). At the same time, a raw material distributor and a two-stage heat conductor reactor (attached) are used. Figure 2 In this system, the raw gas (CO2 24 vol%, H2 72 vol%, 4 vol% N2) enters the gas distribution plate 6 through the raw gas inlet pipe 1 and is then distributed to the raw material distributor 7. The raw gas in the gas distributor 7 enters the catalyst I4 (Na-Fe3O4) bed and then flows into the catalyst II5 (HZSM-5) bed. The gas containing the gasoline product after the reaction flows out of the reactor through the reactor outlet 14. During the reaction operation, the heat exchange system of the reaction device is started simultaneously (heat transfer oil is used in the heat transfer pipe I8, which enters the heat transfer pipe I8 through the heat transfer pipe inlet 10 and flows out from the heat transfer pipe outlet 11 of the reactor through the heat transfer pipe I8 pipeline in the reactor to the heat transfer oil heat exchange equipment; heat transfer pipe II9 uses gas heat transfer, and gas enters the heat transfer pipe II9 through the heat transfer pipe inlet 12 and flows out from the heat transfer pipe outlet 13 of the reactor through the heat transfer pipe II9 pipeline in the reactor to the gas heat exchange equipment). It is worth noting that the raw gas entering the distributor is distributed and flows out only in the catalyst bed I4, and then enters the catalyst bed II5 after reaction. The reacted gas flows out of the reactor through the reactor outlet 14.

[0100] The specific steps of the carbon dioxide hydrogenation reaction to produce gasoline are as follows:

[0101] Step (1) The catalyst is subjected to reduction pretreatment; the pretreated gas (CO224vol%, H272vol%, 4vol% N2) entering the reactor passes through the raw material distributor in sequence through catalyst I4 and catalyst II5, and is subjected to reduction pretreatment at normal pressure (101kPa) and reduction at 350°C for 8h.

[0102] In step (2), the raw gas is preheated to a temperature of 280°C and enters the reactor through the raw gas inlet pipe 15, the gas distribution plate 6 and the raw gas distributor 7 to undergo a high-pressure catalytic reaction.

[0103] The high-temperature and high-pressure reaction gas entering the reactor in step (3) reacts in the reactor designed by the present invention to obtain a reaction mixture. The reaction temperature is 320°C, the pressure is 3.0 MPa, and the space velocity is 8000 mL·g catalyst. -1 ·h -1 .

[0104] Table 1 shows the conversion rate of reactant CO2 and the yield of gasoline product during the reaction time of nearly 1000 hours of operation.

[0105] Table 1

[0106]

[0107] The reaction results show that in this reactor, during the nearly 1000 hours of operation, the conversion rate of the reactant CO2 and the gasoline product yield remained basically stable, the catalyst bed temperature was evenly distributed (310-340℃), and no obvious hot spots appeared.

[0108] Example 2

[0109] The operation was the same as in Example 1, except that the number of raw gas distributors in the reactor was changed from 3 to 10. The raw gas distributor contained four rows of holes. The first and second exhaust holes had diameters of 0.7 mm and 0.5 mm, respectively, with a spacing of 0.7 cm. The third and fourth exhaust holes had diameters of 0.4 mm and a spacing of 1.5 cm. The spacing between the second and third rows of exhaust holes was 1.0 cm. The fourth exhaust holes had diameters of 0.2 mm and a spacing of 2.0 cm.

[0110] Table 2 shows the conversion rate of reactant CO2 and the gasoline product yield during the reaction time of nearly 1000 hours of operation.

[0111] Table 2

[0112]

[0113] The reaction results show that in this reactor, during the nearly 1000 hours of operation, the conversion rate of the reactant CO2 and the gasoline product yield remained basically stable, the catalyst bed temperature was evenly distributed (310-330℃), and no obvious hot spots appeared.

[0114] Example 3

[0115] The operation is the same as that in Example 1, except that the number of porous sub-plates in one reaction zone is adjusted from 1 to 4, and the distance between the first exhaust hole group of the raw gas distributor and the top of the raw gas distributor is adjusted from the current 3 / 4 to 1 / 8 of the total length of the distributor.

[0116] Table 3 shows the conversion rate of reactant CO2 and the yield of gasoline product during the reaction time of nearly 200 hours of operation.

[0117] Table 3

[0118]

[0119] The reaction results show that in this reactor, during the 200-hour reaction time, the conversion rate of the reactant CO2 and the gasoline product yield remained basically stable, the catalyst bed temperature was evenly distributed (310-335°C), and no obvious hot spots appeared.

[0120] Comparative Example 1

[0121] The same as Example 1, except that a traditional fixed bed reactor without a raw material distributor and heat transfer oil was used.

[0122] In this reactor, due to the large amount of heat released by the reaction, the hot spot temperature of the catalyst bed quickly reached above 500°C, the catalyst structure was damaged, the reaction performance dropped rapidly, and the carbon dioxide hydrogenation to gasoline reaction could not operate normally.

[0123] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A feed gas distributor for catalytic CO2 hydrogenation to gasoline, characterized in that: The raw gas distributor includes a shell I, and the shell I encloses a cylindrical cavity; The housing 1 is provided with a plurality of air hole groups along the axial direction; Each of the air hole groups contains a plurality of exhaust air holes arranged along the circumferential direction; The spacing between two adjacent pore groups is arranged axially from top to bottom according to the preset method I; The apertures of the exhaust pores in two adjacent pore groups are also arranged axially from top to bottom according to the preset method II; The preset method I is to gradually increase; or, The preset method I is to gradually increase and then remain unchanged; The preset method II is to gradually reduce; or, The preset method II is to gradually decrease and then remain unchanged; The distance between two adjacent pore groups is n, and the difference between adjacent distances is Δn; Where, 0 ≤ Δn / n ≤ 5; The exhaust holes in each row are staggered up and down; The distance between the first exhaust hole group and the top of the raw gas distributor is greater than or equal to one eighth of the total length of the raw gas distributor.

2. The raw gas distributor according to claim 1, characterized in that 0 ≤Δn / n ≤ 3.

3. The raw gas distributor according to claim 1, characterized in that 0.2≤Δn / n≤1.

4. The raw gas distributor according to claim 1, characterized in that The distance between the first exhaust hole group and the top of the raw gas distributor is greater than or equal to half of the total length of the raw gas distributor.

5. A reactor for catalytic CO2 hydrogenation to gasoline, characterized in that: It includes a raw gas distributor, a shell II, and a porous partition; the porous partition divides the shell II into a first-stage reaction zone, a second-stage reaction zone, and an outlet zone from top to bottom; Catalyst I is placed in the first reaction zone, and catalyst II is placed in the second reaction zone; The raw gas distributor is located in the first reaction zone and is in communication with the first reaction zone; The raw gas distributor includes at least one of the raw gas distributors described in any one of claims 1 to 4.

6. The reactor according to claim 5, characterized in that The first reaction zone is provided with a heat conducting device I; The second reaction zone is provided with a heat conducting device II.

7. The reactor according to claim 6, characterized in that The thermal conductivity of the heat-conducting medium of the heat-conducting device I is not less than the thermal conductivity of the heat-conducting medium of the heat-conducting device II.

8. The reactor according to claim 5, characterized in that The first stage reaction zone and the second stage reaction zone are each independently provided with a plurality of porous sub-plates along the axial direction.

9. The reactor according to claim 8, characterized in that The number of the multi-hole sub-plates is k, where k is a positive integer from 1 to 8.

10. The reactor according to claim 5, characterized in that A gas distribution plate is provided at the inlet of the raw gas distributor.

11. A method for producing gasoline by catalytic CO2 hydrogenation, characterized in that: The reactor according to any one of claims 5 to 10 is used.

12. The method according to claim 11, characterized in that The raw gas containing carbon dioxide and hydrogen enters the first reaction zone through the raw gas distributor, and reacts to obtain logistics A. Logistics A enters the second reaction zone and reacts to obtain logistics B.

13. The method according to claim 12, characterized in that The first reaction zone is filled with an iron-based catalyst to synthesize light olefins from the feed gas containing carbon dioxide and hydrogen; The second stage reaction zone is filled with an acidic molecular sieve catalyst to convert light olefins into gasoline fraction hydrocarbons.

14. The method according to claim 12, characterized in that The stream A contains light olefins; The stream B contains gasoline fraction hydrocarbons.

15. The method according to claim 12, characterized in that The reaction heat of the raw gas containing carbon dioxide and hydrogen in the first reaction zone is discharged through the heat conduction device I; The reaction heat of the logistics A in the second reaction zone is discharged through the heat conduction device II.

16. The method according to claim 11, characterized in that The operating conditions of the reactor are: raw gas: H2 / CO2 volume ratio = 0.5~8, catalyst space velocity: 1000~10000 ml / (g·h), reaction temperature: 250~450℃, and pressure: 1.0~6.0Mpa.

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