Reaction and rectification combined equipment and method for hydrogen storage organic liquid

Abstract

The invention is applicable to the technical field of organic liquid hydrogen storage, and provides reaction and rectification combined equipment and method for hydrogen storage organic liquid, the combined equipment comprises an HDBT storage tank, a preheating kettle, a mixer, a reactor, a rectification tower, a reboiler, a DBT storage tank and a condenser; the HDBT storage tank is connected with the preheating kettle through a pipeline, the preheating kettle is connected with the mixer through a pipeline, the mixer is connected with the top of the reactor, the bottom of the reactor is connected with the rectifying tower, the top of the rectifying tower is connected with the condenser, and the condenser is connected with the mixer and the rectifying tower through pipelines. The bottom of the rectifying tower is connected with the reboiler, and the reboiler is connected with the DBT storage tank and the rectifying tower through pipelines. According to the method, through reasonable design and calculation, the dehydrogenation process of the hydrogen storage organic liquid is improved, the reaction rate is increased by utilizing a reaction and rectification combined technology, the lowest energy consumption condition under the fixed hydrogen production rate is obtained through optimization, and the energy consumption required by the reaction is greatly optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of organic liquid hydrogen storage, and in particular relates to a reaction and distillation combined equipment and method for hydrogen storage in organic liquid. Background Art

[0002] The storage and transportation of hydrogen needs to overcome the challenge of its low boiling point (about 20.27 K), which puts higher requirements on energy consumption and safety. In the existing technology, how to achieve low-cost and high-efficiency hydrogen storage and transportation under the premise of ensuring safety is one of the core issues facing hydrogen energy engineering. Therefore, in the design and implementation of infrastructure, energy consumption, technical reliability and safety need to be comprehensively considered to ensure the overall efficiency of hydrogen logistics.

[0003] As one of the organic liquid hydrogen storage materials (LOHC), dibenzyltoluene (DBT) has attracted much attention due to its good hydrogen storage performance, chemical stability and recycling capacity. The process of combining reaction and distillation not only greatly improves the reaction rate, but also greatly improves the equivalent hydrogen storage density of DBT, but it also brings additional energy consumption due to distillation. Therefore, optimizing the dehydrogenation process of HDBT (fully hydrogenated dibenzyltoluene) to reduce energy consumption as much as possible while satisfying the dehydrogenation rate and hydrogen storage density is one of the hot research directions at present. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a reaction and distillation combined device and method for hydrogen storage in organic liquid, aiming to solve the problems raised in the above-mentioned background technology.

[0005] The embodiment of the present invention is implemented as follows: a reaction and distillation combined equipment for hydrogen storage organic liquid, including a HDBT storage tank, a preheating kettle, a mixer, a reactor, a distillation tower, a reboiler, a DBT storage tank and a condenser; The HDBT storage tank is connected to the preheating kettle through a pipeline, and a first control valve is arranged on the pipeline. The preheating kettle is connected to the mixer through a pipeline, and a second control valve is arranged on the pipeline. The mixer is connected to the top of the reactor through a first liquid pump, and the bottom of the reactor is connected to the distillation tower through a second liquid pump. The top of the distillation tower is connected to the condenser, and the condenser is connected to the mixer and the distillation tower through a pipeline. The bottom of the distillation tower is connected to the reboiler, and the reboiler is connected to the DBT storage tank and the distillation tower through a pipeline.

[0006] According to a further technical solution, the type of the reactor is a tubular reactor, a kettle reactor, a tower reactor or a trickle bed reactor.

[0007] Another object of an embodiment of the present invention is to provide a method for combining reaction and distillation of an organic liquid for hydrogen storage, based on the above-mentioned combined reaction and distillation equipment for an organic liquid for hydrogen storage, comprising the following steps: Step 1, preheating the perhydrodibenzyltoluene in the HDBT storage tank and then pumping it into the mixer; Step 2, pumping the mixed organic liquid in the mixer into a reactor for dehydrogenation reaction, and performing gas-liquid separation to obtain hydrogen and dehydrogenated organic liquid; Step 3, the dehydrogenated organic liquid is pumped into a distillation tower, and after distillation, the steam at the top of the tower is condensed and heat-exchanged in a condenser to obtain an organic liquid with a high concentration of perhydrodibenzyltoluene, and an organic liquid with a high concentration of dibenzyltoluene is obtained from the bottom of the tower. The organic liquid extracted from the top of the tower is pumped back to the mixer and mixed with fresh perhydrodibenzyltoluene. The organic liquid at the bottom of the tower is directly extracted into a DBT storage tank for subsequent hydrogenation.

[0008] According to a further technical solution, in step 1, the mass fraction of perhydrodibenzyltoluene is 90%-99.9%.

[0009] According to a further technical solution, in the step 1, the mass fraction of perhydrodibenzyltoluene in the material extracted from the top of the tower is 75-95%.

[0010] According to a further technical solution, in step 2, the degree of dehydrogenation of the reactor is 20-50%.

[0011] According to a further technical solution, in step 3, the temperature of the condenser is 25-150°C.

[0012] According to a further technical solution, in step 3, the model of the distillation tower is constructed using the number of theoretical plates for calculation, and the number of theoretical plates is 5-80.

[0013] According to a further technical solution, in step 3, the top extraction amount is 0.1-10 times the fresh HDBT feed flow rate.

[0014] The embodiments of the present invention provide a device and method for combining reaction and distillation for hydrogen storage organic liquid. Through reasonable design and calculation, the dehydrogenation process of the hydrogen storage organic liquid is improved, the reaction rate is increased by combining reaction and distillation technology, and the minimum energy consumption conditions under a fixed hydrogen production rate are optimized, thereby greatly optimizing the energy consumption required for the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a reaction and distillation device for hydrogen storage in organic liquid provided in an embodiment of the present invention; Figure 2This is the reboiler energy consumption diagram corresponding to different numbers of trays when the top concentration is 70% under the conditions of fixed dehydrogenation degree and hydrogen production; Figure 3 This is the reboiler energy consumption diagram corresponding to different tray numbers under the conditions of fixed dehydrogenation degree and hydrogen production when the top concentration is 75%; Figure 4 This is the reboiler energy consumption diagram corresponding to different numbers of trays when the top concentration is 80% under the conditions of fixed dehydrogenation degree and hydrogen production; Figure 5 This is the reboiler energy consumption diagram corresponding to different tray numbers under the conditions of fixed dehydrogenation degree and hydrogen production when the top concentration is 85%; Figure 6 This is the reboiler energy consumption diagram corresponding to different numbers of tower plates when the top concentration is 90% under the conditions of fixed dehydrogenation degree and hydrogen production.

[0016] In the attached figure: HDBT storage tank 1; preheating kettle 2; mixer 3; reactor 4; distillation tower 5; reboiler 6; DBT storage tank 7; condenser 8; first control valve 9; second control valve 10; first liquid pump 11; second liquid pump 12. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0019] like Figure 1 As shown, a reaction and distillation device for hydrogen storage of organic liquid provided by one embodiment of the present invention includes a HDBT storage tank 1, a preheating kettle 2, a mixer 3, a reactor 4, a distillation tower 5, a reboiler 6, a DBT storage tank 7 and a condenser 8; The HDBT storage tank 1 is connected to the preheating kettle 2 through a pipeline, and a first control valve 9 is provided on the pipeline. The preheating kettle 2 is connected to the mixer 3 through a pipeline, and a second control valve 10 is provided on the pipeline. The mixer 3 is connected to the top of the reactor 4 through a first liquid pump 11, and the bottom of the reactor 4 is connected to the distillation tower 5 through a second liquid pump 12. The top of the distillation tower 5 is connected to the condenser 8, and the condenser 8 is connected to the mixer 3 and the distillation tower 5 through a pipeline. The bottom of the distillation tower 5 is connected to the reboiler 6, and the reboiler 6 is connected to the DBT storage tank 7 and the distillation tower 5 through a pipeline.

[0020] In the embodiment of the present invention, when used, the perhydrodibenzyltoluene in the HDBT storage tank 1 is first preheated by the preheating kettle 2, and then pumped into the mixer 3 for mixing. After mixing, it is pumped into the reactor 4 by the first pumping pump 11 for dehydrogenation reaction, and gas-liquid separation is performed to obtain hydrogen and dehydrogenated organic liquid. The dehydrogenated organic liquid is pumped into the distillation tower 5 by the second pumping pump 12, and after distillation, the top steam is condensed and heat-exchanged by the condenser 8 to obtain an organic liquid with a high concentration of perhydrodibenzyltoluene, and an organic liquid with a high concentration of dibenzyltoluene is obtained from the bottom of the tower. The organic liquid extracted from the top of the tower is pumped back to the mixer 3 and mixed with fresh perhydrodibenzyltoluene. The dibenzyltoluene with a higher concentration at the bottom of the tower is directly extracted to the DBT storage tank 7 for subsequent hydrogenation.

[0021] As a preferred embodiment of the present invention, the type of the reactor 4 is a tubular reactor, a kettle reactor, a tower reactor or a trickle bed reactor, preferably a tubular reactor or a trickle bed reactor.

[0022] Another embodiment of the present invention provides a method for combining reaction and distillation of an organic liquid for hydrogen storage, based on the above-mentioned combined reaction and distillation equipment for hydrogen storage of an organic liquid, comprising the following steps: Step 1, preheating the perhydrodibenzyltoluene in the HDBT storage tank 1 and then pumping it into the mixer 3; Step 2, pumping the mixed organic liquid in the mixer 3 into the reactor 4 for dehydrogenation reaction, and performing gas-liquid separation to obtain hydrogen and dehydrogenated organic liquid; Step 3, the dehydrogenated organic liquid is pumped into the distillation tower 5, and after distillation, the top steam is condensed and heat-exchanged in the condenser 8 to obtain an organic liquid with a high concentration of perhydrodibenzyltoluene, and an organic liquid with a high concentration of dibenzyltoluene is obtained from the bottom of the tower. The organic liquid extracted from the top of the tower is pumped back to the mixer 3 and mixed with fresh perhydrodibenzyltoluene. The organic liquid at the bottom of the tower is directly extracted to the DBT storage tank 7 for subsequent hydrogenation.

[0023] As a preferred embodiment of the present invention, in step 1, the mass fraction of perhydrodibenzyltoluene is 90%-99.9%, preferably 95%-99.9%.

[0024] As a preferred embodiment of the present invention, in the step 1, the mass fraction of perhydrodibenzyltoluene in the material taken out from the top of the tower is 75-95%, preferably 80-90%.

[0025] As a preferred embodiment of the present invention, in step 2, the dehydrogenation degree of the reactor is 20-50%, preferably 40-60%.

[0026] As a preferred embodiment of the present invention, in step 3, the temperature of the condenser 8 is 25-300°C, preferably 25-100°C.

[0027] As a preferred embodiment of the present invention, in step 3, the model construction of the distillation tower adopts the number of theoretical plates for calculation, and the number of theoretical plates is 5-80.

[0028] As a preferred embodiment of the present invention, in step 3, the top extraction amount is 0.1-10 times the fresh HDBT feed flow rate.

[0029] Several specific examples are provided below to verify the dehydrogenation effect achieved by the present method. The data are summarized in Table 1. Under the conditions of fixed dehydrogenation degree and hydrogen production, the corresponding reboiler energy consumption under different plate numbers and tower top concentrations is as follows: Figure 2-Figure 6 shown.

[0030] Example 1: The purity of HDBT in the top material of the distillation tower 5 is 70%, the purity of DBT in the bottom material of the distillation tower is 90%, the dehydrogenation degree of the reactor is controlled to be 30%, the distillation tower is subjected to a reduced pressure (0.001 MPa) operation, the raw material is 47 kg / h of pure HDBT, the number of theoretical plates of the distillation tower is 40, the number of feed plates is 24, the top condenser temperature is 70°C, the bottom temperature is 304°C, the top temperature is 294.1°C, the bottom extraction is 28.3 kg / h, and the hydrogen production is 1 kg / h. The total energy consumption of the process = organic liquid preheating energy consumption + reaction endothermic energy consumption + distillation tower energy consumption + vacuum pump energy consumption. In this embodiment, the total energy consumption of the process is 40 kW·h.

[0031] Using a distillation tower to separate HDBT and DBT and re-introducing the high-concentration HDBT into the reactor is beneficial to maintaining a high concentration of HDBT in the reactor, thereby accelerating the reaction and greatly accelerating the dehydrogenation reaction rate. In addition, 90% pure DBT is extracted from the bottom of the distillation tower, which can be regarded as 100% HDBT entering the system and 90% DBT and H2 leaving the system. The equivalent dehydrogenation degree can be regarded as 90%, and the hydrogen storage density reaches 5.6%, which greatly reduces the transportation cost of hydrogen.

[0032] Example 2: The purity of HDBT in the top produced material of the distillation tower is 90%, the purity of DBT in the bottom produced material of the distillation tower is 95%, the dehydrogenation degree of the reactor is controlled to be 40%, the distillation tower is subjected to reduced pressure (0.001 MPa), the raw material is 20 kg / h of pure HDBT, the theoretical number of plates of the distillation tower is 40, the number of feed plates is 24, the top condenser temperature is 60°C, the bottom temperature is 304.5°C, the top temperature is 293.2°C, the bottom production is 18.9 kg / h, the hydrogen production is 1.1 kg / h, and the total energy consumption of the process = organic liquid preheating energy consumption + reaction endothermic energy consumption + distillation tower energy consumption + vacuum pump energy consumption = 28 kW·h.

[0033] The bottom of the distillation tower is extracted with DBT of 95% purity, which can be regarded as 100% HDBT entering the system, and 95% DBT and H2 leaving the system. The equivalent dehydrogenation degree can be regarded as 95%, and the hydrogen storage density reaches 5.9%.

[0034] Comparative Example 1: The purity of HDBT in the top produced material of the distillation tower is 90%, the purity of DBT in the bottom produced material of the distillation tower is 95%, the dehydrogenation degree of the reactor is controlled to be 40%, the distillation tower is subjected to reduced pressure (0.001 MPa), the raw material is 34 kg / h of pure HDBT, the number of theoretical plates of the distillation tower is 30, the number of feed plates is 18, the top condenser temperature is 60°C, the bottom temperature is 304.5°C, the top temperature is 293.2°C, the bottom production is 18.9 kg / h, the hydrogen production is 1.1 kg / h, and the total energy consumption of the process = organic liquid preheating energy consumption + reaction endothermic energy consumption + distillation tower energy consumption + vacuum pump energy consumption = 32 kW·h.

[0035] The bottom of the distillation tower is extracted with DBT of 95% purity, which can be regarded as 100% HDBT entering the system, and 95% DBT and H2 leaving the system. The equivalent dehydrogenation degree can be regarded as 95%, and the hydrogen storage density reaches 5.9%.

[0036] Comparative Example 2: The purity of HDBT in the top produced material of the distillation tower is 90%, the purity of DBT in the bottom produced material of the distillation tower is 95%, the dehydrogenation degree of the reactor is controlled to be 40%, the distillation tower is subjected to reduced pressure (0.001 MPa), the raw material is 27 kg / h of pure HDBT, the theoretical number of plates of the distillation tower is 20, the number of feed plates is 11, the top condenser temperature is 60°C, the bottom temperature is 304.5°C, the top temperature is 293.2°C, the bottom production is 18.9 kg / h, the hydrogen production is 1.1 kg / h, and the total energy consumption of the process = organic liquid preheating energy consumption + reaction endothermic energy consumption + distillation tower energy consumption + vacuum pump energy consumption = 48 kW·h.

[0037] The bottom of the distillation tower is extracted with DBT of 95% purity, which can be regarded as 100% HDBT entering the system, and 95% DBT and H2 leaving the system. The equivalent dehydrogenation degree can be regarded as 95%, and the hydrogen storage density reaches 5.9%.

[0038] Table 1 Parameters of Examples and Comparative Examples

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A combined reaction and distillation device for hydrogen storage organic liquid, It is characterized in that Including HDBT storage tank, preheating kettle, mixer, reactor, distillation tower, reboiler, DBT storage tank and condenser; The HDBT storage tank is connected to the preheating kettle through a pipeline, and a first control valve is arranged on the pipeline. The preheating kettle is connected to the mixer through a pipeline, and a second control valve is arranged on the pipeline. The mixer is connected to the top of the reactor through a first liquid pump, and the bottom of the reactor is connected to the distillation tower through a second liquid pump. The top of the distillation tower is connected to the condenser, and the condenser is connected to the mixer and the distillation tower through a pipeline. The bottom of the distillation tower is connected to the reboiler, and the reboiler is connected to the DBT storage tank and the distillation tower through a pipeline.

2. The combined reaction and distillation equipment for hydrogen storage in organic liquid according to claim 1, It is characterized in that The type of the reactor is a tubular reactor, a tank reactor, a tower reactor or a trickle bed reactor.

3. A method for combining reaction and distillation of an organic liquid for hydrogen storage, based on the combined reaction and distillation device for hydrogen storage of an organic liquid according to any one of claims 1 to 2, It is characterized in that The following steps are involved: Step 1, preheating the perhydrodibenzyltoluene in the HDBT storage tank and then pumping it into the mixer; Step 2, pumping the mixed organic liquid in the mixer into a reactor for dehydrogenation reaction, and performing gas-liquid separation to obtain hydrogen and dehydrogenated organic liquid; Step 3, the dehydrogenated organic liquid is pumped into a distillation tower, and after distillation, the steam at the top of the tower is condensed and heat-exchanged in a condenser to obtain an organic liquid with a high concentration of perhydrodibenzyltoluene, and an organic liquid with a high concentration of dibenzyltoluene is obtained from the bottom of the tower. The organic liquid extracted from the top of the tower is pumped back to the mixer and mixed with fresh perhydrodibenzyltoluene. The organic liquid at the bottom of the tower is directly extracted into a DBT storage tank for subsequent hydrogenation.

4. The method for combining reaction and distillation of an organic liquid for hydrogen storage according to claim 3, It is characterized in that In step 1, the mass fraction of perhydrodibenzyltoluene is 90%-99.9%.

5. The method for combining reaction and distillation of an organic liquid for hydrogen storage according to claim 4, It is characterized in that In step 2, the dehydrogenation degree of the reactor is 20-50%.

6. The method for combining reaction and distillation of an organic liquid for hydrogen storage according to claim 3, It is characterized in that In step 3, the temperature of the condenser is 25-150°C.

7. The method for combining reaction and distillation of an organic liquid for hydrogen storage according to claim 3, It is characterized in that In step 3, the model of the distillation tower is constructed using the number of theoretical plates for calculation, and the number of theoretical plates is 5-80.

8. The method for combining reaction and distillation of an organic liquid for hydrogen storage according to claim 3, It is characterized in that In step 3, the tower top extraction amount is 0.1-10 times the fresh HDBT feed flow rate.

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