A hydrogen slurry material and its dynamic dehydrogenation reaction system

Abstract

The present invention proposes a hydrogen slurry material and a dynamic dehydrogenation reaction system thereof, adopts a spiral tube reactor to improve and increase the contact interface morphology and contact time between the hydrogen slurry material and the catalyst, and realizes the purpose of improving the dehydrogenation efficiency by means of dynamic dehydrogenation of the hydrogen slurry material through circulating flow; and solves the problem of insufficient stability of the dynamic dehydrogenation reaction process by means of a fluid heat transfer medium and a spiral tube reaction device.

Description

Technical Field

[0001] The invention relates to the field of hydrogen energy and hydrogen storage materials, and in particular to a hydrogen slurry material and a dynamic dehydrogenation reaction system thereof. Background Art

[0002] Hydrogen slurry storage technology combines organic liquid hydrogen storage technology with solid-state hydrogen storage technology to prepare a fluid hydrogen storage slurry, which achieves hydrogen storage and release through a reversible addition / dehydrogenation reaction between hydrogen storage materials and hydrogen. Hydrogen storage slurry can achieve high-density hydrogen storage and transportation at room temperature and pressure, and can be widely used in long-distance hydrogen energy storage and transportation and large-scale hydrogen energy storage systems. It has a wide range of application scenarios in the fields of hydrogen energy and chemical industry.

[0003] The low dehydrogenation efficiency of hydrogen slurry is a difficulty that hinders its development. Its dehydrogenation usually needs to be carried out at low pressure and high temperature. The reaction efficiency is low and it is easier to produce side reactions, which leads to carbon deposition and catalyst deactivation. Improving the dehydrogenation reaction efficiency of organic hydrogen storage liquid in hydrogen slurry is a key issue that needs to be solved urgently.

[0004] At present, precious metal catalysts are commonly used to improve the dehydrogenation efficiency of organic liquids. Patent CN111054382A discloses a catalyst for the dehydrogenation reaction of organic liquid hydrogen storage materials and a preparation method thereof. The invention uses a catalyst containing platinum elements or their oxides to solve the problems of poor anti-carbon deposition and large carbon deposition in the dehydrogenation reaction process in the prior art. Patent CN112237936A discloses a catalyst for the dehydrogenation reaction of organic liquid hydrogen storage materials. The invention combines precious metals and graphene, focusing on solving the problems of high reaction temperature, rapid catalyst deactivation, high operating costs caused by membrane reactions, large equipment investment, and difficult maintenance in traditional gas phase dehydrogenation technology. A high-stability liquid phase dehydrogenation catalyst and a preparation method thereof are provided. When the method is used for the dehydrogenation reaction of organic liquid hydrogen storage materials, carbon-hydrogen bonds can be activated under liquid phase conditions, and the migration and aggregation of precious metals can be prevented, which can greatly improve the stability of the catalyst. Although both of the above methods achieve the dehydrogenation reaction of organic liquid hydrogen storage materials, the use of precious metal catalysts greatly increases the cost of organic liquid applications in the field of hydrogen energy.

[0005] Whether hydrogen slurry materials are used for hydrogen storage and transportation or hydrogen energy storage, they will eventually need to release hydrogen in the form of hydrogen gas at the hydrogen-using site. Therefore, developing an efficient dynamic dehydrogenation reaction system for hydrogen slurry materials is also an urgent problem to be solved. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a dynamic hydrogen slurry dehydrogenation reaction system, which adopts a spiral tube reactor to improve and increase the contact interface morphology and contact time between the hydrogen slurry material and the catalyst, and realizes the purpose of improving the dehydrogenation efficiency by means of dynamic dehydrogenation of the hydrogen slurry material through circulating flow; the problem of insufficient stability of the dynamic dehydrogenation reaction process is solved by means of a fluid heat transfer medium and a spiral tube reaction device.

[0007] The present invention provides a method for preparing a hydrogenated hydrogen slurry material, comprising:

[0008] The first step is to add the hydrogen slurry material into the high-pressure reactor, and then perform a reciprocating operation of evacuating and passing hydrogen through the high-pressure reactor to remove gas impurities and trace moisture in the high-pressure reactor, and finally maintain the reactor in a vacuum state, preferably the reciprocating operation is performed 3 to 5 times;

[0009] The second step is to heat the vacuumed high-pressure reactor to 150-300° C., introduce 1-10 MPa of hydrogen, control the stirring speed of the reactor, and carry out a hydrogenation reaction until the hydrogen slurry material is hydrogenated and saturated. Preferably, the heating temperature is 220-290° C., the hydrogen pressure is 4-8 MPa, and the stirring speed is 600-1200 rpm.

[0010] The hydrogen slurry material comprises a solid hydrogen storage material, the metal components of which are one or more of the three elements of magnesium, nickel and lanthanum.

[0011] Wherein, by weight, the magnesium powder is 50 to 95 parts, and the lanthanum-nickel alloy powder is 1 to 50 parts. Preferably, the magnesium powder is 65 to 85 parts, and the lanthanum-nickel alloy powder is 15 to 35 parts.

[0012] Wherein, the preparation method of the solid hydrogen storage material is:

[0013] After magnesium powder and lanthanum nickel alloy powder are mechanically mixed, a hydrogenation ball milling reaction is carried out to obtain a solid metal hydride hydrogen storage material; the conditions of the hydrogenation ball milling reaction are: hydrogen pressure of 1 to 5 MPa, ball-to-material ratio of 10:1 to 120:1, ball milling speed of 200 to 1000 rpm, and ball milling time of 1 to 24 h. Preferably, the hydrogen pressure is 3 to 4.5 MPa, the ball-to-material ratio is 90:1 to 110:1, the ball milling speed is 400 to 800 rpm, and the ball milling time is 7 to 10 h.

[0014] Wherein, the hydrogen slurry material also contains an organic hydrogen storage material, and the organic liquid hydrogen storage material has a strong interaction with the solid metal hydride hydrogen storage material. The organic liquid hydrogen storage material includes a mixture of one or more of cyclohexane, methylcyclohexane, tetralin, decalin, perhydroethylcarbazole, perhydrocarbazole, perhydrodibenzyltoluene and derivatives thereof, preferably, a mixture of one or more of methylcyclohexane, decalin, perhydroethylcarbazole, perhydrodibenzyltoluene and derivatives thereof.

[0015] The mass ratio of the solid hydrogen storage material to the organic liquid hydrogen storage material is 1:19 to 1:1, and preferably, the mass ratio of the solid hydrogen storage material to the organic liquid hydrogen storage material is 1:10 to 1:4.

[0016] The present invention also provides a dynamic dehydrogenation reaction system for hydrogen slurry materials, the device comprising a vacuum system, a material storage system, a dehydrogenation reaction system, a gas-liquid separation system, a slurry circulation system and a released hydrogen metering system.

[0017] The storage system is used to store hydrogen slurry, including hydrogen slurry material added externally and refluxed by the device. The storage tank is equipped with an electric heating and stirring device externally, which can preheat and stir the hydrogen slurry material in the storage tank.

[0018] The main body of the dehydrogenation reactor in the dynamic dehydrogenation reaction device is a spiral tube structure, and the reactor is filled with porous dehydrogenation catalysts of different particle sizes.

[0019] Beneficial Effects of the Invention

[0020] The present invention discloses a dehydrogenation reaction system for hydrogen slurry materials and a method for using the same. The system comprises a vacuum system, a feeding system, a dehydrogenation reaction system, a gas-liquid separation system, and a slurry circulation system.

[0021] 1. The spiral tubular reactor is equipped with porous Pt / Al2O3 catalyst particles. Hydrogen slurry flows through the surface of the catalyst particles to cause dehydrogenation reaction, which effectively improves the reaction efficiency and the service life of the catalyst;

[0022] 2. The circulating flow method can improve the efficiency of hydrogen slurry dehydrogenation reaction;

[0023] The hydrogen slurry material dehydrogenation reaction system and the use method thereof disclosed in the present invention can efficiently and continuously dehydrogenate the hydrogen slurry material, thereby significantly improving the output and use efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a photo of the hydrogen slurry in Example 1;

[0025] Figure 2 is the particle size distribution of the solid phase in the hydrogen slurry in Example 1;

[0026] Figure 3 Hydrogen slurry hydrogenation kinetics curve;

[0027] Figure 4 This is a schematic structural diagram of the dynamic dehydrogenation reaction system of the present invention;

[0028] Figure 5 Hydrogen slurry dehydrogenation efficiency diagram;

[0029] Figure 6Dehydrogenation kinetic curve of static dehydrogenation reaction by constant volume method. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing a hydrogenated hydrogen slurry material. Specifically, in the first step, the hydrogen slurry material is added into a high-pressure reactor, and then the high-pressure reactor is vacuumed and hydrogen is passed through the reactor repeatedly to remove gas impurities and trace moisture in the high-pressure reactor, and finally the reactor is kept in a vacuum state, and the reciprocating operation is preferably performed 3 to 5 times;

[0031] The second step is to heat the vacuumed high-pressure reactor to 150-300° C., introduce 1-10 MPa of hydrogen, control the stirring speed of the reactor, and carry out a hydrogenation reaction until the hydrogen slurry material is hydrogenated and saturated. Preferably, the heating temperature is 220-290° C., the hydrogen pressure is 4-8 MPa, and the stirring speed is 600-1200 rpm.

[0032] The hydrogen slurry material comprises a solid hydrogen storage material, the metal components of which are one or more of the three elements of magnesium, nickel and lanthanum.

[0033] Furthermore, in parts by mass, the magnesium powder is 50 to 95 parts, and the lanthanum-nickel alloy powder is 1 to 50 parts. Preferably, the magnesium powder is 65 to 85 parts, and the lanthanum-nickel alloy powder is 15 to 35 parts.

[0034] The solid hydrogen storage material preparation method is:

[0035] After magnesium powder and lanthanum nickel alloy powder are mechanically mixed, a hydrogenation ball milling reaction is carried out to obtain a solid metal hydride hydrogen storage material; the conditions of the hydrogenation ball milling reaction are: hydrogen pressure of 1 to 5 MPa, ball-to-material ratio of 10:1 to 120:1, ball milling speed of 200 to 1000 rpm, and ball milling time of 1 to 24 h. Preferably, the hydrogen pressure is 3 to 4.5 MPa, the ball-to-material ratio is 90:1 to 110:1, the ball milling speed is 400 to 800 rpm, and the ball milling time is 7 to 10 h.

[0036] The hydrogen slurry material also contains an organic hydrogen storage material. The organic liquid hydrogen storage material has a strong interaction with the solid metal hydride hydrogen storage material. The organic liquid hydrogen storage material includes a mixture of one or more of cyclohexane, methylcyclohexane, tetralin, decalin, perhydroethylcarbazole, perhydrocarbazole, perhydrodibenzyltoluene and derivatives thereof, preferably, a mixture of one or more of methylcyclohexane, decalin, perhydroethylcarbazole, perhydrodibenzyltoluene and derivatives thereof.

[0037] The mass ratio of the solid hydrogen storage material to the organic liquid hydrogen storage material is 1:19 to 1:1. Preferably, the mass ratio of the solid hydrogen storage material to the organic liquid hydrogen storage material is 1:10 to 1:4.

[0038] The present invention also provides a dynamic dehydrogenation reaction system for hydrogen slurry materials, which includes a vacuum system, a material storage system, a dehydrogenation reaction system, a gas-liquid separation system, a slurry circulation system and a hydrogen release metering system. Pipelines and valves are used to form a closed-loop complete set of equipment according to the functional order of each system.

[0039] The storage system is used to store hydrogen slurry, including hydrogen slurry material added externally and refluxed by the device. The storage tank is equipped with an electric heating and stirring device externally, which can preheat and stir the hydrogen slurry material in the storage tank.

[0040] The slurry circulation system is used to continuously transport the hydrogen slurry material in the storage tank to the dehydrogenation reaction system, and is transported by a peristaltic pump, a diaphragm pump, or a mud pump. Preferably, a peristaltic pump is used for transport, and the flow rate is 1 to 500 ml / min.

[0041] The main body of the dehydrogenation reactor in the dynamic dehydrogenation reaction system is a spiral tubular structure, and the reactor is filled with porous dehydrogenation catalysts of different particle sizes. The spiral reactor is made of stainless steel and quartz glass, the dehydrogenation catalyst is Pt / Al2O3, Pt-M / Al2O3, Pt / C, Pt-M / C, M is one or more of Ni, Co, In, Mo, Ru, Pd, and the particle size of the porous dehydrogenation catalyst is 0.5mm to 10mm, preferably 1mm to 5mm.

[0042] The hydrogen slurry material dynamic dehydrogenation reaction system uses a circulating pump to continuously transport the hydrogen slurry material to the dehydrogenation reaction system, and a thin liquid layer of catalytic hydrogen slurry is formed on the surface of the dehydrogenation catalyst particles and is dynamically updated. The hydrogen slurry material containing hydrogen leaves the dehydrogenation reaction system and enters a gas-liquid separator for separation. The hydrogen is discharged from the upper outlet and enters a hydrogen metering system. The hydrogen slurry material flows back to the storage tank, and the cycle is repeated until the dehydrogenation reaction is completed.

[0043] The hydrogen slurry material dynamic dehydrogenation reaction system is to add a certain amount of hydrogen slurry material, and after the dynamic catalytic dehydrogenation is completed, the total amount of hydrogen released and the rate of hydrogen released are used to evaluate the dehydrogenation performance of the hydrogen slurry material. The catalytic dynamic dehydrogenation reaction temperature is 180°C to 350°C, and the preferred dehydrogenation temperature is 280°C to 320°C.

[0044] The following embodiments and drawings are used to describe the implementation methods of the present invention in detail, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0045] Example 1

[0046] After mixing magnesium powder and LaNi5 particles accounting for 16wt% of the total mass, hydrogenation ball milling is performed to obtain solid metal hydride hydrogen storage material powder; the hydrogenation ball milling conditions are: hydrogen pressure of 4MPa, ball-to-material ratio of 100:1, ball milling speed of 500rpm, and ball milling time of 500min.

[0047] The solid hydrogen storage material obtained by hydrogenation ball milling and the organic hydrogen storage liquid were mixed in a glove box filled with argon at a solid-liquid mass ratio of 2:8 and mechanically stirred for 120 minutes. The mixed hydrogen slurry material was Figure 1 As shown, the solid particle size in the slurry is Figure 2 As shown by the red curve, the solid particle size obtained by ball milling is Figure 2 As shown by the black solid line, the median size of solid particles is 1.47 μm, and 99.9% of the solid particles are less than 16 μm;

[0048] The obtained hydrogen slurry material is added to the reactor, and then the reactor is evacuated and hydrogen is passed through, the reactor is cleaned, and finally the reactor is kept in a vacuum state; the evacuated reactor is heated to 280°C, 6MPa hydrogen is passed through, and the stirring speed of the reactor is controlled to be 1000rpm to carry out hydrogenation reaction until the hydrogen slurry material is hydrogenated and saturated, which is recorded as hydrogenated hydrogen slurry material. The hydrogenation kinetic curve of hydrogen slurry is shown in Figure 3 As shown, after 18 hours of hydrogenation reaction, the hydrogenation amount of the hydrogen slurry was 5.8wt%.

[0049] A fixed bed dehydrogenation reaction system is used to evaluate the dehydrogenation reaction of hydrogenated hydrogen slurry materials. The schematic diagram of the device is shown in the figure. Figure 4 The specific implementation is as follows:

[0050] Open the vacuum pump 16, open the air inlet valve 14 and the air extraction valve 15, and evacuate the reaction device until the pressure gauge 43 shows 0 MPa, and keep it for 1 hour; close the air extraction valve 15, open the hydrogen bottle and the pressure relief valve 11, and purge hydrogen until the pressure gauge 43 reaches 0.1 MPa, and close the hydrogen bottle valve and the pressure relief valve 11; open the vacuum pump 16 and the air extraction valve 15, and evacuate the reaction device until the pressure gauge 43 shows 0 MPa, and keep it for 1 hour. Close the vacuum pump 16, the air inlet valve 14 and the air extraction valve 15.

[0051] The slurry is added into the storage tank 24 through the feed port 2, and the butterfly valve 21 is closed; the electric heating jacket 23 is turned on to preheat the slurry in the storage tank 24 to 200° C. The temperature of the slurry in the storage tank is displayed by the thermocouple 28.

[0052] The high-pressure plunger pump 25 is turned on to inject the slurry in the storage tank 24 into the dehydrogenation reactor 3 through the insulation pipe. The slurry enters through the bottom of the spiral catalytic dehydrogenation reaction bed 33, flows through the Pt / Al2O3 catalyst in the reaction bed, and flows out through the top of the reaction bed after the dehydrogenation reaction occurs. The dehydrogenation reaction temperature is 300°C and the pressure is 0.1MPa. The reaction temperature is controlled by an oil bath, and the oil bath temperature is displayed by a thermocouple 32. At the same time, the thermocouple 32 can also monitor the temperature of the upper, middle and lower ends of the reaction bed.

[0053] Open valve 41, and the slurry after the reaction reaches the gas-liquid separation tank 42 through the condenser 4, the gas is discharged through valve 47, and the total amount of hydrogen released by the slurry dehydrogenation reaction is monitored by mass flow meter 48; the slurry after gas-liquid separation enters the storage tank 24 for circulation through valve 45, or is discharged through valve 44.

[0054] After cyclic dehydrogenation reaction, the hydrogen slurry dehydrogenation amount is 5wt%, and the dehydrogenation efficiency is 86%. Figure 5 shown.

[0055] The hydrogen slurry and Pt / Al2O3 catalyst were placed in a closed dehydrogenation reactor, and the dehydrogenation effect of the hydrogen slurry was statically tested using the constant volume method. The dehydrogenation kinetic curve is shown in Figure 6 As shown, at 300°C, the dehydrogenation amount of hydrogen slurry after 12 hours is 1.81wt%, and the dehydrogenation efficiency is 31%.

[0056] All of the above are primary implementations of this intellectual property and do not set limitations on other forms of implementation of this new product and / or new method. Those skilled in the art will use this important information and modify the above content to achieve similar implementations. However, all modifications or transformations based on the new product of this invention belong to the reserved rights.

[0057] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing hydrogenated hydrogen slurry material, characterized in that: include: The first step is to add the hydrogen slurry material into the high-pressure reactor, and then perform a reciprocating operation of evacuating and passing hydrogen through the high-pressure reactor to remove gas impurities and trace moisture in the high-pressure reactor, and finally maintain the reactor in a vacuum state, and perform a reciprocating operation 3 to 5 times; The second step is to heat the vacuumed high-pressure reactor to 150-300°C, introduce 1-10 MPa of hydrogen, control the stirring speed of the reactor to 600-1200 rpm, and carry out hydrogenation reaction until the hydrogen slurry material is saturated with hydrogen; The hydrogen slurry material comprises a solid hydrogen storage material, and the preparation method of the solid hydrogen storage material is: By weight, the magnesium powder is 65-85 parts, and the lanthanum-nickel alloy powder is 15-35 parts. The magnesium powder and the lanthanum-nickel alloy powder are mechanically mixed, and then subjected to hydrogenation ball milling reaction to obtain a solid metal hydride hydrogen storage material; The conditions of the hydrogenation ball milling reaction are: hydrogen pressure of 1-5 MPa, ball-to-material ratio of 10:1-120:1, ball milling speed of 200-1000 rpm, and ball milling time of 1-24 h.

2. The method for preparing hydrogenated hydrogen slurry material according to claim 1, characterized in that: The hydrogen slurry material further comprises an organic hydrogen storage material, including a mixture of one or more of cyclohexane, tetralin, decalin, perhydroethylcarbazole, perhydrocarbazole, perhydrodibenzyltoluene and derivatives thereof.

3. The method for preparing hydrogenated hydrogen slurry material according to claim 2, characterized in that: The mass ratio of the solid hydrogen storage material to the organic liquid hydrogen storage material is 1:19-1:

1.

4. A dynamic dehydrogenation reaction system for hydrogen slurry materials, characterized by: The invention comprises a vacuum system, a material storage system, a dehydrogenation reaction system, a gas-liquid separation system, a slurry circulation system and a hydrogen release metering system. The material storage system is used to store hydrogen slurry, including hydrogen slurry material prepared by the method according to any one of claims 1 to 3 which is added externally and refluxed by the device. The material storage tank is provided with an electric heating and stirring device externally, which can preheat and stir the hydrogen slurry material in the material storage tank. The main body of the dehydrogenation reactor in the dynamic dehydrogenation reaction system is a spiral tubular structure, and the reactor is filled with porous dehydrogenation catalysts of different particle sizes.

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