High-efficiency reactor and process for fixed reaction tube alternating molecular sieve membrane separation

Abstract

The application discloses a kind of fixed reaction tube alternative molecular sieve membrane separation high-efficiency reactor and process, high-efficiency dehydrogenation reaction tube includes stainless steel reaction tube and molecular sieve membrane tube, stainless steel reaction tube is filled with supported catalyst, the aperture of molecular sieve membrane tube is between hydrogen and organic hydrogen storage carrier molecule size, only allow hydrogen small molecule to pass through.Stainless steel reaction tube is coaxial with the one end of molecular sieve membrane tube and is sealed in series.The application completes catalytic reaction in stainless steel reaction tube, separates hydrogen in molecular sieve membrane tube, breaks reaction equilibrium, and improves dehydrogenation rate.The reactor has miniaturization light weight, and is suitable for carrying small car or hydrogenation station on-line hydrogen supply.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dehydrogenation hydrogen supply, and particularly relates to a high-efficiency reactor and process for organic liquid-phase dehydrogenation reaction by coupling a multi-section fixed bed reaction tube with a multi-section molecular sieve membrane separation module. BACKGROUND

[0002] Hydrogen energy is considered as one of the most likely substitutes for fossil fuels, and the only product of hydrogen combustion in a fuel cell or combustion chamber is water, which does not cause environmental pollution. At present, hydrogen energy has been widely applied in distributed power generation, hydrogen energy transportation, energy storage, electronic industry, metallurgical industry and other fields. However, hydrogen storage and hydrogen supply technology is still a bottleneck restricting hydrogen energy fuel cell technology, and the hydrogen storage technology has the disadvantages of low hydrogen storage capacity, high cost and low safety.

[0003] Common hydrogen storage technologies include pressurized hydrogen storage, cryogenic hydrogen storage, alloy hydrogen storage, active carbon or other carbon material hydrogen storage, MOFs hydrogen storage and liquid organic hydrogen storage, etc. Among them, the pressurized hydrogen storage is the earliest and is also the most widely used, but its hydrogen storage mass density is low, and the pressurized hydrogen storage has the potential danger of hydrogen embrittlement; the cryogenic liquid hydrogen storage has high volume energy density, but the liquefaction process consumes high energy, and a liquefied tank with good adiabatic performance is required, which has strict requirements on materials; the advantage of hydrogen storage alloy is large volume hydrogen storage capacity, but hydrogen itself can cause hydrogen damage, hydrogen corrosion, hydrogen embrittlement and poor recyclability of the hydrogen storage alloy material; the carbon material hydrogen storage has low adsorption temperature (active carbon) or small volume hydrogen storage capacity (carbon nanotubes), which limits its application range; the preparation conditions of the metal organic framework material hydrogen storage have great influence, and the metal organic framework material hydrogen storage is still in the research stage.

[0004] The liquid organic hydrogen storage has many advantages, including large hydrogen storage density, safety of storage and long-distance transportation, easy maintenance of equipment and pipelines, easy use of existing conveying pipelines and equipment, low cost of the technology, and recyclable hydrogen storage material, so the liquid organic hydrogen storage becomes the most feasible method in the hydrogen energy storage and transportation process. Many industrial and academic research institutions in the world actively invest in the development of practical liquid organic hydrogen storage technology. Major industrial countries in the world such as Germany, Switzerland, Japan and the United Kingdom are actively engaged in this research.

[0005] The hydrogen storage and hydrogen release process of the liquid organic hydrogen storage technology is a cyclic process, which specifically includes three stages of hydrogenation reaction of the hydrogen storage agent, storage and transportation of the hydrogen storage medium and dehydrogenation process of the hydrogenated liquid organic matter, and the specific process is as follows: first, the hydrogen energy is stored by the catalytic hydrogenation reaction of the hydrogen storage agent; then, the hydrogenated liquid organic matter is stored and transported by using the existing equipment; finally, the hydrogen stored in the hydrogen storage medium is released by the dehydrogenation reaction, and the hydrogen is supplied to the end user.

[0006] At present, the selection of suitable hydrogen storage medium, hydrogen storage and transportation of liquid organic liquid have been relatively mature, and the main difficulty lies in the dehydrogenation technology of liquid organic hydrogen carrier. At present, the dehydrogenation technology has problems such as low activity of dehydrogenation catalyst, high dehydrogenation temperature and slow dehydrogenation rate. The dehydrogenation of organic hydrogen storage carrier is a strong endothermic reaction, and the reaction speed is slow. The dehydrogenation of conventional full-mixed flow stirred tank reactor has the disadvantages of long reaction time, discontinuous reaction, unstable dehydrogenation flow rate, difficult product removal and the like; the continuous fixed bed reactor has the problems of low heat transfer efficiency, slow reaction rate, incomplete product dehydrogenation and the like, and the highest dehydrogenation rate can only reach 80%. SUMMARY

[0007] In order to solve the above technical problems, improve the reaction conversion rate, and realize the miniaturization and light weight of the dehydrogenation equipment, so that it can be carried on the mobile vehicle or on-line hydrogen supply to the hydrogenation station. For this purpose, the present application provides a kind of multi-section fixed bed reaction tube coupling multi-section molecular sieve membrane separation module's high efficiency reactor and process.

[0008] The technical scheme adopted is as follows:

[0009] On the one hand, the present application provides a kind of fixed reaction tube alternation molecular sieve membrane separation's high efficiency reactor, the high efficiency reactor includes the shell with hollow cavity, the both ends of the shell are respectively equipped with the communicating feed pipe and discharge pipe, the feed pipe and the discharge pipe of the shell are respectively equipped with the tube plate sealedly connected with the inner side of the shell, a plurality of dehydrogenation reaction tubes are arranged between the tube plates, a hydrogen gas collecting pipe is arranged on the shell between the two tube plates, the hydrogen gas collecting pipe is communicated with the hollow cavity of the shell, the dehydrogenation reaction tube includes a stainless steel reaction tube and a molecular sieve membrane tube, the stainless steel reaction tube is filled with a supported catalyst, the pore size of the molecular sieve membrane tube is between the size of hydrogen and organic hydrogen storage carrier molecules, and one end of the stainless steel reaction tube is coaxially and sealingly connected with one end of the molecular sieve membrane tube.

[0010] Preferably, the molecular sieve membrane tube is a DDR all-silicon molecular sieve membrane tube with a pore size of 0.36*0.44 nm.

[0011] Further, the inner side of the molecular sieve membrane tube is provided with a plurality of annular support frames for enhancing the overall strength of the molecular sieve membrane tube.

[0012] Further, the outer side of the stainless steel reaction tube is surrounded by an electric heating pipe.

[0013] Preferably, the active component in the supported catalyst is one or more of ruthenium, platinum, palladium and nickel metal.

[0014] Further, the dehydrogenation reaction tube comprises multiple groups of the stainless steel reaction tube and the molecular sieve membrane tube, and the stainless steel reaction tube and the molecular sieve membrane tube are arranged in an alternating series.

[0015] Preferably, the dehydrogenation reaction tube comprises 3-6 groups of the stainless steel reaction tube and the molecular sieve membrane tube.

[0016] Further, the dehydrogenation reaction tube comprises 3-6 groups of the stainless steel reaction tube and the molecular sieve membrane tube, the stainless steel reaction tube is surrounded by an electric heating tube, the front end and the rear end of each group of the molecular sieve membrane tube are respectively provided with the tube plate which is sealingly connected to the inner side of the shell, the front and rear tube plates of the molecular sieve membrane tube form a hydrogen gas collection cavity, and a corresponding hydrogen gas collecting pipe is arranged on the shell corresponding to the hydrogen gas collection cavity, and the hydrogen gas collecting pipe is in communication with the corresponding hydrogen gas collection cavity.

[0017] Further, the shell is provided with 25-400 dehydrogenation reaction tubes.

[0018] Further, a feed cavity is arranged between the feed pipe and the adjacent tube plate, and porcelain balls for uniform distribution are filled in the feed cavity; and a reaction product collection cavity is arranged between the discharge pipe and the adjacent tube plate.

[0019] Further, a compressor with a pressure of -0.1 to -0.04 MPa is connected to the hydrogen gas collecting pipe, and the shell is externally provided with a heat preservation layer.

[0020] The application also provides a multi-stage fixed bed reaction tube coupled with a multi-stage molecular sieve membrane separation process, in which organic hydrogen storage liquid is heated to 150-300 DEG C to enter a high-efficiency reactor; the organic hydrogen storage liquid is fully reacted with a catalyst in a stainless steel reaction tube, and the generated hydrogen gas enters a molecular sieve membrane tube; the generated hydrogen gas is separated by the molecular sieve membrane tube and discharged by a hydrogen gas collecting pipe; the remaining organic hydrogen storage liquid enters a next-stage reaction tube for catalytic dehydrogenation reaction, and then enters a next-stage molecular sieve membrane separation unit for hydrogen separation; the process of catalytic dehydrogenation in the reaction tube, hydrogen separation in the molecular sieve membrane, breaking of reaction equilibrium and promotion of reaction kinetics dehydrogenation rate are alternately performed in multiple stages, and finally the organic hydrogen storage liquid is discharged from a discharge pipe of the shell.

[0021] Further, the electric heating tube on the stainless steel reaction tube is heated when the organic hydrogen storage liquid passes through the stainless steel reaction tube; after the organic hydrogen storage liquid passes through the alternating stainless steel reaction tube catalyst reaction and the molecular sieve membrane tube dehydrogenation, the generated hydrogen gas is discharged by a corresponding hydrogen gas collecting pipe through a compressor negative pressure suction, and the remaining organic hydrogen storage liquid is discharged from a discharge pipe of the shell.

[0022] The organic hydrogen storage liquid is 18H-dibenzyl toluene, 12H-benzyl toluene, methylcyclohexane and 12H-N-ethyl carbazole organic hydrogen storage medium.

[0023] The technical scheme of the present application has the following advantages:

[0024] A. The present application designs a multi-channel multi-section reactor structure, so that the organic hydrogen storage medium catalytically reacts when passing through the stainless steel reaction tube, hydrogen adsorbed on the surface of the catalyst can be separated from the catalyst in time under a negative pressure of-0.1~-0.04 MPa, and is separated from the organic hydrogen storage medium through the molecular sieve membrane tube, thereby breaking the reaction kinetic balance, continuously promoting the reaction in the direction of dehydrogenation, and improving the dehydrogenation conversion rate.

[0025] B. The present application sets the dehydrogenation reaction tube into a plurality of groups of stainless steel reaction tubes and molecular sieve membrane tubes in series, so that the organic hydrogen storage medium is subjected to multi-stage reactions through the dehydrogenation reaction tube in the high-efficiency reactor, mass transfer is strengthened, the reaction is more complete, and the dehydrogenation efficiency is improved.

[0026] C. The present application further sets a high-efficiency electric heating tube in the high-efficiency reactor, precisely provides heat by controlling the electric heating tube surrounding the outside of the stainless steel reaction tube, eliminates a large number of reaction sections and heating equipment, realizes miniaturization and light weight of the dehydrogenation equipment, and enables the dehydrogenation equipment to be carried on a mobile device.

[0027] D. The high-efficiency dehydrogenation reaction tube of the present application includes a stainless steel reaction tube and a molecular sieve membrane tube, the stainless steel reaction tube is filled with a supported catalyst, the pore size of the molecular sieve membrane tube is between the sizes of hydrogen and organic hydrogen storage carrier molecules, and only hydrogen small molecules are allowed to pass. One end of the stainless steel reaction tube is coaxially and sealingly connected with one end of the molecular sieve membrane tube. The high-efficiency reactor includes a shell with a hollow cavity, the shell is provided with a feeding pipe and a discharging pipe at two ends, respectively, and is provided with a tube plate sealingly connected with the inner side of the shell near the feeding pipe and the discharging pipe, respectively, a plurality of dehydrogenation reaction tubes sealingly connected with the tube plates are arranged between the tube plates, a hydrogen collecting pipe is arranged on the shell between the two tube plates and is in communication with the hollow cavity of the shell. The present application completes the catalytic reaction in the stainless steel reaction tube and separates hydrogen in the molecular sieve membrane tube, breaks the reaction balance, and improves the dehydrogenation rate. The reactor is miniaturized and lightened, and is suitable for being carried on a small vehicle or an online hydrogen supply station. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present application, the drawings required in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 is the structure diagram of the multi-reaction-dehydrogenation unit reaction tube provided by the present application;

[0030] Figure 2 is the structure diagram of the high-efficiency reactor provided by the present application.

[0031] The meanings of the symbols in the figure are as follows:

[0032] 1-dehydrogenation reaction tube

[0033] 11-stainless steel reaction tube, 12-molecular sieve membrane tube, 13-electric heating tube

[0034] 2-casing

[0035] 21-feed tube, 22-discharge tube, 23-tube plate, 24-hydrogen gas collecting tube

[0036] a-feeding cavity, b-reaction product collecting cavity, c-hydrogen gas collecting cavity DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0038] As shown in Figure 1 , the present application provides a dehydrogenation reaction tube 1, which comprises a stainless steel reaction tube 11 and a molecular sieve membrane tube 12. The stainless steel reaction tube 11 is filled with a supported catalyst, and the pore size of the molecular sieve membrane tube 12 is between the sizes of hydrogen and organic hydrogen storage carrier molecules. One end of the stainless steel reaction tube 11 is coaxially and sealingly connected with one end of the molecular sieve membrane tube 12, and the two are sealingly connected by graphite rings at the connection section to form a dehydrogenation reaction tube. In order to improve the hydrogen conversion rate, the present application can be provided with a plurality of stainless steel reaction tubes 11 and molecular sieve membrane tubes 12 connected in series in one dehydrogenation reaction tube. The preferred number of stainless steel reaction tubes 11 and molecular sieve membrane tubes 12 in the present application is preferably 3-6 respectively, and the stainless steel reaction tubes 11 and the molecular sieve membrane tubes 12 are sealingly arranged in an alternating series. The active component in the supported catalyst is one or more of ruthenium, platinum, palladium and nickel metals.

[0039] This invention preferably uses DDR all-silicon molecular sieve membrane tubes, which possess high hydrogen permeability and chemical stability. Table 1 shows the kinetic diameters of various molecules in the organic hydrogen storage carrier dehydrogenation reaction system. As can be seen from the table, hydrogen has the smallest molecular kinetic diameter (0.289 nm), while the molecular kinetic diameters of the organic hydrogen storage carrier are larger before and after the reaction. The pore size of the DDR molecular sieve membrane tube is 0.36 nm × 0.44 nm, falling between the molecular sizes of hydrogen and the organic hydrogen storage carrier, making it suitable as a dehydrogenation reaction tube.

[0040] Table 1. Molecular dynamic diameters of different methylcyclohexane-toluene systems

[0041]

[0042] To further prevent damage to the equipment due to negative pressure, multiple ring-shaped support frames are added inside the molecular sieve membrane tube, which provides excellent reinforcement and support.

[0043] like Figure 2 As shown, the present invention also provides a high-efficiency reactor, including a shell 2 with a hollow cavity. A feed pipe 21 and a discharge pipe 22 are respectively provided at both ends of the shell 2. Tube sheets 23 are respectively provided near the feed pipe 21 and the discharge pipe 22, which are sealed and connected to the inner side of the shell 2. A plurality of dehydrogenation reaction tubes 1 are provided between the tube sheets 23 and sealed thereto. A hydrogen collection pipe 24 is provided on the shell 2 between the two tube sheets 23. The hydrogen collection pipe 24 is connected to the hollow cavity of the shell 2. The hydrogen collection pipe 24 can be connected to a compressor. The compressor provides a negative pressure of -0.1 to 0.04 MPa to draw out the hydrogen adsorbed on the surface of the catalyst from the molecular sieve membrane tube.

[0044] The dehydrogenation reaction tube 1 preferably includes 3-6 sets of stainless steel reaction tubes 11 and molecular sieve membrane tubes 12 connected in series. Electric heating tubes 13 are surrounded between the stainless steel reaction tubes 11, and heat insulation layers are provided between the electric heating tubes 13. The heating temperature of the electric heating tubes 13 can be controlled by an external controller. Meanwhile, tube sheets 23 are respectively provided at the front and rear ends of each group of molecular sieve membrane tubes 12, which are sealed and connected to the inner side of the shell 2. The front and rear tube sheets of the molecular sieve membrane tubes 12 form a hydrogen collection chamber c, and a corresponding hydrogen collection pipe 24 is provided on the shell 2 corresponding to the hydrogen collection chamber c. The hydrogen collection pipe 24 is connected to the corresponding hydrogen collection chamber c. A feed chamber a is provided between the feed pipe 21 and its adjacent tube sheet 23, and ceramic balls for uniform distribution are filled in the feed chamber a. A reaction product collection chamber b is provided between the discharge pipe 22 and its adjacent tube sheet 23. The feed chamber a is connected to the raw material pump, and each dehydrogenation reaction tube 1 is fixed on the tube sheet 23 in the feed chamber a and is evenly distributed.

[0045] The internal cavity of a high-efficiency reactor preferably contains 25 to 400 dehydrogenation reaction tubes. The hydrogen storage carrier entering the high-efficiency reactor first undergoes catalytic dehydrogenation reaction in the first stainless steel reaction tube at 150-300°C, and then enters the DDR all-silicon molecular sieve membrane tube to remove hydrogen from the organic hydrogen storage liquid under a negative pressure of -0.1 to -0.04 MPa. The dehydrogenated hydrogen storage carrier enters the next stainless steel reaction tube to continue catalytic dehydrogenation. Through step-by-step reaction, hydrogen is removed in a timely manner, the reaction equilibrium is broken, the hydrogen removal efficiency is higher, the dehydrogenation is more thorough, the product separation is simple, and the dehydrogenation equipment can be miniaturized and lightweight, so that it can be mounted in a mobile device.

[0046] Taking the dehydrogenation of 18H-dibenzyltoluene as an example, the dehydrogenation of 18H-dibenzyltoluene is a reversible, strongly endothermic reaction that requires a large amount of heat. Furthermore, the equilibrium conversion rate is low at low temperatures. Removing hydrogen from the product after each stage of the catalytic reaction using a molecular sieve membrane tube helps to shift the reaction equilibrium to the right and improve the conversion rate. Below is a series of steps in the 18H-DBT dehydrogenation reaction, showing how a series of catalytic reactions completely removes hydrogen.

[0047]

[0048] The high-efficiency reactor provided by this invention is suitable for organic hydrogen storage media such as 18H-dibenzyltoluene, 12H-benzyltoluene, methylcyclohexane, and 12H-N-ethylcarbazole. Through the design of a multi-channel, multi-stage reactor structure, the organic hydrogen storage medium repeatedly passes through a stainless steel reaction tube with a catalyst and a molecular sieve membrane tube. Under a negative pressure of -0.1 to -0.04 MPa provided by the compressor, hydrogen adsorbed on the catalyst surface can be separated from the catalyst in a timely manner and released from the organic hydrogen storage medium through the molecular sieve membrane tube, breaking the reaction kinetic equilibrium and continuously driving the reaction towards dehydrogenation, thus improving the dehydrogenation conversion rate. The multi-stage, stepwise catalytic reaction in the high-efficiency reactor enhances mass transfer, making the reaction more complete and improving dehydrogenation efficiency. The high-efficiency reactor incorporates a modular, high-efficiency heat exchange system, eliminating the need for numerous reaction sections and heating equipment, achieving miniaturization and lightweighting of the dehydrogenation equipment, allowing it to be mounted on a mobile device.

[0049] To improve the heating efficiency of the stainless steel reaction tube inside the shell, and because the negative pressure state of the molecular sieve membrane tube connected to the compressor is not conducive to heating with heat transfer media such as heat transfer oil, this invention installs an electric heating tube on the outside of the stainless steel reaction tube in the dehydrogenation reaction tube. The temperature is adjusted via a control panel to maintain the reaction temperature at 150~300℃. Since the dehydrogenation reaction of organic hydrogen storage liquid is an endothermic reaction, the reaction temperature in the reactor bed needs to be uniform in both the transverse and longitudinal directions, with a temperature difference of less than 5℃. The multi-stage structure of the coupled multi-stage reactor can control the reaction to proceed slowly, preventing violent reactions and sudden temperature drops, while also occupying a small volume and having strong temperature control capabilities.

[0050] Furthermore, the present invention also fills the feed chamber of the high-efficiency reactor with ceramic balls to distribute the material evenly into the reactor.

[0051] The multi-channel fixed-bed coupled multi-segment molecular sieve membrane separation process provided by this invention comprises the following steps:

[0052] The organic hydrogen storage liquid is heated to a reaction inlet temperature of 150℃~300℃ and then enters the high-efficiency reactor. The organic hydrogen storage liquid reacts fully with the catalyst in the stainless steel reaction tube and enters the molecular sieve membrane tube together with the generated hydrogen gas. The molecular sieve membrane tube separates the generated hydrogen gas and discharges it through the hydrogen gas collection pipe. The remaining organic hydrogen storage liquid is discharged from the outlet pipe of the shell.

[0053] When the organic hydrogen storage liquid passes through the stainless steel reaction tube, the electric heating tube on it is controlled to heat it. After the organic hydrogen storage liquid undergoes catalyst reaction in alternating stainless steel reaction tubes and dehydrogenation in molecular sieve membrane tubes, the generated hydrogen gas is discharged through the corresponding hydrogen gas collection tube by negative pressure suction of the compressor, and the remaining organic hydrogen storage liquid is discharged from the discharge pipe of the shell.

[0054] Process flow description: The raw material organic hydrogen storage liquid (18H-DBT, 12H-MBT, etc.) is heated to a reaction inlet temperature of 150-300℃ and enters a high-efficiency reactor with a fixed bed coupled with multiple molecular sieve membrane tubes. The discharge pipe of the high-efficiency reactor discharges the dehydrogenated organic hydrogen storage liquid, and the hydrogen gas discharged from the hydrogen gas collection pipe is the hydrogen gas separated by the molecular sieve membrane tubes.

[0055] The reactants are evenly distributed through the feed chamber and enter a multi-bundle stainless steel reaction tube. At a reaction temperature of 150-300℃, they react fully with ruthenium-based or nickel-based catalysts and, together with the generated hydrogen, enter a molecular sieve membrane tube for separation. After the hydrogen is separated, the remaining organic hydrogen storage liquid continues to enter the next stage stainless steel reaction tube for catalytic reaction, and the generated hydrogen is separated again through the next stage molecular sieve membrane tube. This process of catalytic dehydrogenation in the reaction tube, hydrogen separation in the molecular sieve membrane, breaking the reaction equilibrium, and promoting the dehydrogenation rate in the reaction kinetics is carried out in multiple alternating stages. Finally, the organic hydrogen storage liquid is discharged from the outlet pipe of the shell. Through multiple catalytic reactions and molecular sieve membrane separations, the hydrogen conversion rate is higher.

[0056] Under the negative pressure of -0.1 to -0.04 MPa generated by the compressor, hydrogen is drawn out from the hydrogen collection pipe and enters the hydrogen storage unit, thus completing the dehydrogenation process.

[0057] Example 1

[0058] 60-mesh supported 2.0% Pt / γ-Al₂O₃ catalyst pellets were packed into stainless steel reaction tubes. Each stainless steel reaction tube had an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm. These tubes were connected to individual molecular sieve membrane tubes (each with an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm) via screw fittings. Three stainless steel reaction tubes and three molecular sieve membrane tubes were connected to form a dehydrogenation reaction tube with coupled multi-segment molecular sieve membrane separation. A total of 36 dehydrogenation reaction tubes were used, arranged into a high-efficiency reactor core, housed within a high-efficiency reactor shell. The core reactor had a volume of 2.5 L and a catalyst loading of 0.45 L.

[0059] The dehydrogenation feedstock was methylcyclohexane, preheated to 240°C, with an inlet pressure of 1.7 bar, a vacuum of -0.08 MPa in the hydrogen collection chamber, and a methylcyclohexane feed rate of 20 ml / min.

[0060] Under these process conditions, the compressor outlet hydrogen yield is 11.81 L / min, the dehydrogenation rate reaches 92.6%, the CO content in the hydrogen is less than 1 ppm, and the CH4 content is less than 50 ppm. It produces 600–800 liters of high-purity hydrogen (99.99% or higher) per hour. Example

[0061] 60-mesh supported 2.0% Pt / γ-Al₂O₃ catalyst pellets were packed into stainless steel reaction tubes. Each stainless steel reaction tube had an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm. These tubes were connected to individual molecular sieve membrane tubes (each with an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm) via screw fittings. Five stainless steel reaction tubes and five molecular sieve membrane tubes were connected to form a high-efficiency dehydrogenation reaction tube with coupled multi-segment molecular sieve membrane separation. A total of 64 dehydrogenation reaction tubes were used, arranged into a high-efficiency reactor core, which was placed inside the high-efficiency reactor shell. The core reactor volume was 5.9 L, and the catalyst loading was 1.3 L.

[0062] The dehydrogenation feedstock is 12H-MBT, preheated to 250℃, with an inlet pressure of 1.5 bar, a vacuum of -0.08 MPa in the hydrogen collection chamber, and a 12H-MBT feed rate of 50 ml / min.

[0063] Under these process conditions, the compressor outlet hydrogen yield is 31.09 L / min, the dehydrogenation rate reaches 96.4%, the CO content in the hydrogen is less than 1 ppm, and the CH4 content is less than 50 ppm. It produces 1500–2000 liters of high-purity hydrogen (over 99.99%) per hour. Example

[0064] 60-mesh kneaded 2.0% Pt / γ-Al₂O₃ catalyst pellets were packed into stainless steel reaction tubes. Each stainless steel reaction tube had an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm. These tubes were connected to individual molecular sieve membrane tubes (each with an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm) via screw fittings. Five stainless steel reaction tubes and five molecular sieve membrane tubes were connected to form a dehydrogenation reaction tube with coupled multi-segment molecular sieve membrane separation. A total of 64 dehydrogenation reaction tubes were used, arranged into a high-efficiency reactor core, housed within a high-efficiency reactor shell. The core reactor had a volume of 5.9 L and a catalyst loading of 1.3 L.

[0065] The dehydrogenation feedstock was 12H-N-ethylcarbazole, preheated to 150°C, with an inlet pressure of 1.9 bar, a hydrogen collection chamber vacuum of -0.08 MPa, and a 12H-N-ethylcarbazole feed rate of 70 ml / min.

[0066] Under these process conditions, the compressor outlet hydrogen yield is 42.95 L / min, the dehydrogenation rate reaches 94.83%, the CO content in the hydrogen is less than 1 ppm, and the CH4 content is less than 50 ppm. It produces 2200–2700 liters of high-purity hydrogen (over 99.99%) per hour. Example

[0067] 60-mesh kneaded 2.0% Pt / γ-Al₂O₃ catalyst pellets were packed into stainless steel reaction tubes. Each stainless steel reaction tube had an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm. These tubes were connected to individual molecular sieve membrane tubes (each with an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm) via screw fittings. Three stainless steel reaction tubes and three molecular sieve membrane tubes were connected to form a dehydrogenation reaction tube with coupled multi-segment molecular sieve membrane separation. A total of 64 dehydrogenation reaction tubes were used, arranged into a high-efficiency reactor core, placed within the reactor shell. The core reactor volume was 3.54 L, and the catalyst loading was 0.78 L.

[0068] The dehydrogenation feedstock is 18H-DBT, preheated to 250℃, with an inlet pressure of 1.6 bar, a vacuum of -0.08 MPa in the hydrogen collection chamber, and a 18H-DBT feed rate of 50 ml / min.

[0069] Under these process conditions, the compressor outlet hydrogen yield is 29.22 L / min, the dehydrogenation rate reaches 89.34%, the CO content in the hydrogen is less than 1 ppm, and the CH4 content is less than 50 ppm. It produces 1500–2000 liters of high-purity hydrogen (99.99% or higher) per hour. Example

[0070] 60-mesh kneaded 2.0% Pt / γ-Al₂O₃ catalyst pellets were packed into stainless steel reaction tubes. Each stainless steel reaction tube had an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm. These tubes were connected to individual molecular sieve membrane tubes (each with an inner diameter of 8 mm, an outer diameter of 10 mm, and a length of 80 mm) via screw fittings. Five stainless steel reaction tubes and five molecular sieve membrane tubes were connected to form a dehydrogenation reaction tube with coupled multi-segment molecular sieve membrane separation. A total of 64 dehydrogenation reaction tubes were used, arranged into a high-efficiency reactor core, housed within a high-efficiency reactor shell. The core reactor had a volume of 5.9 L and a catalyst loading of 1.3 L.

[0071] The dehydrogenation feedstock is 18H-DBT, preheated to 300℃, with an inlet pressure of 1.6 bar, a vacuum of -0.08 MPa in the hydrogen collection chamber, and a 18H-DBT feed rate of 50 ml / min.

[0072] Under these process conditions, the compressor outlet hydrogen yield is 32.14 L / min, the dehydrogenation rate reaches 98.27%, the CO content in the hydrogen is less than 1 ppm, and the CH4 content is less than 50 ppm. It produces 1500–2000 liters of high-purity hydrogen (over 99.99%) per hour.

[0073] Any aspects not covered in this invention are applicable to existing technologies.

[0074] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-efficiency reactor with fixed reaction tubes and alternating molecular sieve membrane separation, characterized in that, The high-efficiency reactor includes a shell (2) with a hollow cavity. The two ends of the shell (2) are respectively provided with a feed pipe (21) and a discharge pipe (22). Tube plates (23) that are sealed to the inner side of the shell (2) are respectively provided at the feed pipe (21) and the discharge pipe (22) near the shell (2). A plurality of dehydrogenation reaction tubes (1) are provided between the tube plates (23) and sealed to them. A hydrogen collection pipe (24) is provided on the shell (2) between the two tube plates (23). The hydrogen collection pipe (24) is connected to the hollow cavity of the shell (2). The dehydrogenation reaction tube (1) includes a stainless steel reaction tube (11) and a molecular sieve membrane tube (12). The stainless steel reaction tube (11) is filled with a supported catalyst. The pore size of the molecular sieve membrane tube (12) is between the molecular size of hydrogen and organic hydrogen storage carrier. One end of the stainless steel reaction tube (11) and one end of the molecular sieve membrane tube (12) are coaxially and sealed in series. The dehydrogenation reaction tube (1) includes multiple sets of stainless steel reaction tubes (11) and molecular sieve membrane tubes (12), and the stainless steel reaction tubes (11) and molecular sieve membrane tubes (12) are arranged alternately in series; each set of molecular sieve membrane tubes (12) has a tube sheet (23) at the front end and the rear end, which is sealed and connected to the inner side of the shell (2). The front and rear tube sheets of the molecular sieve membrane tubes (12) form a hydrogen collection chamber (c), and a corresponding hydrogen collection pipe (24) is provided on the shell (2) corresponding to the hydrogen collection chamber (c). The hydrogen collection pipe (24) is connected to the corresponding hydrogen collection chamber (c). A feed chamber (a) is provided between the feed pipe (21) and the adjacent tube sheet (23), and the feed chamber (a) is filled with ceramic balls for uniform distribution; a reaction product collection chamber (b) is provided between the discharge pipe (22) and the adjacent tube sheet (23).

2. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, The molecular sieve membrane tube (12) is a DDR all-silicon molecular sieve membrane tube with a pore size of 0.36×0.44nm.

3. The high-efficiency reactor with fixed reaction tubes and alternating molecular sieve membrane separation according to claim 2, characterized in that, The inner side of the molecular sieve membrane tube (12) is provided with several annular support frames to enhance the overall strength of the molecular sieve membrane tube.

4. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, The stainless steel reaction tube (11) is surrounded by an electric heating tube (13).

5. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, The active component in the supported catalyst is one or more of ruthenium, platinum, palladium, and nickel metals.

6. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, The dehydrogenation reaction tube (1) includes 3 to 6 sets of stainless steel reaction tubes (11) and molecular sieve membrane tubes (12).

7. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, The shell (2) contains 25 to 400 dehydrogenation reaction tubes (1).

8. The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube according to claim 1, characterized in that, A compressor with a pressure of -0.1 to -0.04 MPa is connected to the hydrogen collection pipe (24), and an insulation layer is provided on the outside of the housing (2).

9. A fixed reaction tube alternating molecular sieve membrane separation process, characterized in that, The high-efficiency reactor with alternating molecular sieve membrane separation in a fixed reaction tube as described in any one of claims 1-8 is used. The organic hydrogen storage liquid is heated to a reaction inlet temperature of 150°C to 300°C and then enters the high-efficiency reactor. The organic hydrogen storage liquid reacts fully with the catalyst in the stainless steel reaction tube and enters the molecular sieve membrane tube together with the generated hydrogen gas. The generated hydrogen is separated by the molecular sieve membrane tube and discharged through the hydrogen collection tube; the remaining organic hydrogen storage liquid enters the next stage reaction tube for catalytic dehydrogenation reaction, and then enters the next stage molecular sieve membrane separation unit to separate hydrogen. Finally, the organic liquid phase carrier is discharged from the discharge tube of the shell.

10. The fixed reaction tube alternating molecular sieve membrane separation process according to claim 9, characterized in that, When the organic hydrogen storage liquid passes through the stainless steel reaction tube, the electric heating tube on it is controlled to heat it. After the organic hydrogen storage liquid undergoes catalyst reaction in alternating stainless steel reaction tubes and dehydrogenation in molecular sieve membrane tubes, the generated hydrogen gas is discharged through the corresponding hydrogen gas collection tube by negative pressure suction of the compressor, and the remaining organic hydrogen storage liquid is discharged from the discharge pipe of the shell.

11. The fixed reaction tube alternating molecular sieve membrane separation process according to claim 10, characterized in that, The organic hydrogen storage liquid is 18H-dibenzyltoluene, 12H-benzyltoluene, methylcyclohexane, or 12H-N-ethylcarbazole organic hydrogen storage medium.

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