A small-scale ethanol high-pressure reforming hydrogen production device with a segmented structure

Abstract

The present invention discloses a small-scale high-pressure ethanol reforming hydrogen production device with a segmented structure, which includes a control unit and an ethanol catalytic reforming hydrogen production unit. The ethanol catalytic reforming hydrogen production unit includes an inlet pipe, a conical end cap, a circular cylinder body and its end cap arranged in sequence; a gas distribution device is provided at a position near the conical end cap at the front end of the circular cylinder body, and a flat gas distribution grid is provided at a position near the end cap at the rear end of the circular cylinder body. A segmented hydrogen separation device is arranged inside the circular cylinder body, and the segmented hydrogen separation devices are connected by a connecting pipe in the core part. A plurality of palladium membrane tubes are arranged around the connecting pipe of the core part of each segment of the hydrogen separation device; the palladium membrane tubes of adjacent segments of the hydrogen separation device are arranged staggeredly. It is applicable to a high-pressure hydrogen production reactor. At the same time, in order to weaken the concentration polarization effect of the membrane module, promote the positive shift of the chemical reaction equilibrium, and improve the hydrogen production rate and hydrogen recovery rate.

Description

Technical Field

[0001] The present invention relates to a green hydrogen preparation technology, and in particular to a small-scale ethanol high-pressure reforming hydrogen production device with a segmented structure. Background Art

[0002] At present, bioethanol reforming is a typical green hydrogen production technology. Bioethanol can be produced by fermenting biomass or food and animal husbandry waste. No additional carbon dioxide is produced during the production and use cycle of bioethanol hydrogen, which belongs to the technical category of green hydrogen production. As an emerging clean energy, hydrogen has been widely used in fuel cells, smelting and food processing.

[0003] Compared with hydrogen-rich fuels such as natural gas and methanol, ethanol is environmentally friendly and has high hydrogen yields. Its specific energy is much higher than that of methanol, and ethanol is widely available without excessive consumption of fossil energy. Therefore, it is of great significance to use ethanol, especially bioethanol, to reform hydrogen. Green hydrogen production equipment can produce high-purity hydrogen, which can provide a safe, environmentally friendly and economical hydrogen source for fuel cells, industrial hydrogen, food processing hydrogen and other application fields.

[0004] However, the current hydrogen storage and production technologies still have much room for improvement. Common methods of hydrogen storage and production include high-pressure gaseous hydrogen storage, solid material hydrogen storage, organic liquid hydrogen storage, and reforming hydrogen production. Among them, reforming hydrogen production refers to the process in which hydrogen-rich fuels such as natural gas, methanol or ethanol undergo a reforming catalytic reaction under certain temperature and pressure conditions under the action of a catalyst to convert them into H2 and CO2. Moreover, most catalysts remain in the research and development stage, and there is a lack of an integrated high-pressure reactor for catalytic reforming hydrogen production and separation.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a small-scale ethanol high-pressure reforming hydrogen production device with a segmented structure to solve the above-mentioned technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] The small-scale ethanol high-pressure reforming hydrogen production device with segmented structure of the present invention comprises a control unit and an ethanol catalytic reforming hydrogen production unit, wherein the ethanol catalytic reforming hydrogen production unit comprises an inlet pipe, a conical end cover, a circular cylinder and a tail cover arranged in sequence;

[0009] A gas distribution device is provided at the front end of the circular cylinder near the conical end cap, a flat gas distribution grid is provided at the rear end of the circular cylinder near the tail cap, a segmented hydrogen separation device is provided inside the circular cylinder, and the multi-segment hydrogen separation devices are connected by a connecting pipe at the core. A plurality of palladium membrane tubes are provided around the connecting pipe at the core of each hydrogen separation device.

[0010] Each hydrogen separation device is a purification section, and the cavity inside the circular cylinder at its front end is a catalytic section.

[0011] The outlet of the connecting pipe at the core passing through the flat gas distribution grid and the tail cap is the residue outlet.

[0012] The outlet of the cavity at the rear end of the last hydrogen separation device passing through the flat gas distribution grid and the tail cap is the pure hydrogen outlet.

[0013] Compared with the prior art, the small-scale ethanol high-pressure reforming hydrogen production device provided by the present invention has segmented catalysis and separation and purification, which can promote the forward progress of the catalytic reforming reaction, greatly improve the conversion rate of ethanol and the hydrogen production. The segmented palladium membrane tube enhances the mechanical strength by reducing its own structural size, and strengthens the potential of the reactor for pressurized reaction. It also effectively inhibits the concentration polarization phenomenon during the hydrogen separation process, reduces the radial mass transfer resistance, increases the hydrogen flux per unit area of the palladium membrane, and increases the hydrogen recovery rate. Description of the Drawings

[0014] Figure 1 It is the control flow chart of the small-scale ethanol high-pressure reforming hydrogen production device with a segmented type provided by the embodiment of the present invention;

[0015] Figure 2 It is the schematic diagram of the ethanol reforming coupled hydrogen separation unit with three-stage reforming hydrogen production and separation and purification provided by the embodiment of the present invention;

[0016] Figure 3a It is the schematic diagram of the separation device provided by the embodiment of the present invention;

[0017] Figure 3b It is the sectional view of the separation device provided by the embodiment of the present invention.

[0018] In the figure:

[0019] 1. Inlet pipe, 2. Conical end cap, 3. Gas distribution device, 4. Circular cylinder, 5. Segmented hydrogen separation device, 6. Connecting pipe, 7. Flat gas distribution grid, 8. Pure hydrogen outlet, 9. Residue outlet, 10. Palladium membrane tube. Detailed Embodiments

[0020] The following describes clearly and completely the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments, which does not constitute a limitation to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0021] First, the following explanations are given for the terms that may be used in this article:

[0022] The term "and / or" means that either one or both of the two can be realized. For example, X and / or Y means that it includes both the case of "X" or "Y" and the three cases of "X and Y".

[0023] The description of terms such as "comprise", "include", "contain", "have" or other similar semantics should be interpreted as non-exclusive inclusion. For example: including a certain technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction condition, processing condition, parameter, algorithm, signal, data, product or article, etc.) should be interpreted as not only including the explicitly listed certain technical feature element, but also including other technical feature elements well-known in the art that are not explicitly listed.

[0024] The term "consisting of" means excluding any unexplicitly listed technical feature element. If this term is used in a claim, this term will make the claim a closed type, making it not contain technical feature elements other than the explicitly listed technical feature elements, except for the related conventional impurities. If this term only appears in a sub-clause of a claim, then it only limits the elements explicitly listed in that sub-clause, and the elements recorded in other sub-clauses are not excluded from the overall claim.

[0025] Unless otherwise clearly specified or limited, terms such as "install", "connect", "join", "fix" and other terms should be understood in a broad sense. For example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this article can be understood according to specific situations.

[0026] The terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of description and simplification, and do not expressly or impliedly mean that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to this article.

[0027] The content not described in detail in the embodiments of the present invention belongs to the prior art well-known to those skilled in the art. For those conditions not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the art or the conditions recommended by the manufacturer. For the reagents or instruments not specified in the embodiments of the present invention for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0028] The small ethanol high-pressure reforming hydrogen production device with a segmented type of the present invention includes a control unit and an ethanol catalytic reforming hydrogen production unit. The ethanol catalytic reforming hydrogen production unit includes an inlet pipe, a conical end cap, a circular cylinder body and its end cap arranged in sequence.

[0029] A gas distribution device is provided at a position near the conical end cap at the front end of the circular cylinder body, a flat gas distribution grid is provided at a position near the end cap at the rear end of the circular cylinder body, a segmented hydrogen separation device is provided inside the circular cylinder body, and the segmented hydrogen separation devices are connected by a connecting pipe in the core part. A plurality of palladium membrane tubes are provided around the connecting pipe in the core part of each segmented hydrogen separation device.

[0030] Each segmented hydrogen separation device is a purification section, and the cavity inside the circular cylinder body at its front end is a catalytic section.

[0031] The outlet of the connecting pipe in the core part passing through the flat gas distribution grid and the end cap is the residue outlet.

[0032] The outlet of the cavity at the rear end of the last segmented hydrogen separation device passing through the flat gas distribution grid and the end cap is the pure hydrogen outlet.

[0033] The palladium membrane tubes of adjacent segmented hydrogen separation devices are arranged staggeredly.

[0034] The inlet pipe of the ethanol catalytic reforming hydrogen production unit is connected with a pressure and flow control module and a vaporization device. The pressure and flow control module is provided with an air inlet, and the vaporization device is connected with a solution pump of an ethanol solution.

[0035] The residue outlet of the ethanol catalytic reforming hydrogen production unit is connected with an electric back pressure valve, and the waste gas outlet of the electric back pressure valve is connected with the vaporization device.

[0036] The ethanol catalytic reforming hydrogen production unit is equipped with a temperature sensor and a pressure sensor.

[0037] The control unit is respectively connected to the pressure and flow control module, the vaporization device, the solution pump, the electric back pressure valve, the temperature sensor and the pressure sensor.

[0038] In summary, the small-scale ethanol high-pressure reforming hydrogen production device with a segmented type in the embodiment of the present invention is applicable to a high-pressure hydrogen production reactor. At the same time, in order to weaken the concentration polarization effect of the membrane module, promote the positive shift of the chemical reaction equilibrium, and improve the hydrogen production rate and hydrogen recovery rate.

[0039] In order to more clearly show the technical solution provided by the present invention and the technical effects produced, the following uses specific embodiments to describe in detail what is provided in the embodiments of the present invention.

[0040] Embodiment 1

[0041] As Figure 1 shown, it is a control flow chart of the ethanol reforming hydrogen production device. Air outputs appropriate flow and pressure through the pressure and flow control module. Ethanol solution with a certain water-alcohol ratio is sent into the vaporization device through the solution pump, and the solution is vaporized in the device through two heating methods of electric auxiliary heating and waste heat recovery, and catalytic reforming hydrogen production reaction is carried out with air in the ethanol catalytic reforming unit. This device has both hydrogen production and separation functions, and can separate and purify hydrogen in real time during the reforming hydrogen production reaction to obtain high-purity hydrogen. The pressure in the ethanol catalytic reforming unit is controlled by the back pressure valve on the tail gas discharge route, and the reaction pressure in the device can be changed by adjusting the outlet pressure of the back pressure valve to provide different pressure reaction environments. The residual heat in the waste gas is recovered in the vaporization device to improve the energy utilization efficiency.

[0042] The whole device has the function of semi-automatically adjusting the reaction pressure and the oxygen-alcohol molar ratio, and realizes its function through a pressure control and regulation system. The control elements in the system include an intelligent control module, a pressure sensor, a back pressure valve, a pressure control module, a vaporization device, and a solution pump. The pressure and flow control module inputs and outputs the flow signals of the pressure signals, follows the instructions of the intelligent control module, and adjusts the intake pressure and intake flow. The electric heating equipment in the vaporization device adjusts the heating power according to the liquid feed amount of the ethanol solution to ensure complete vaporization. The temperature and pressure sensors monitor the reaction pressure and temperature in the reaction device in real time and transmit the signals to the intelligent control module. The electric control back pressure valve receives the pressure signal from the intelligent control module and adjusts the back pressure value.

[0043] The regulation method of the whole system realizes the ethanol reforming reaction with different pressures and oxygen-alcohol ratios by inputting the reaction pressure value and the oxygen-alcohol ratio in the intelligent module. The whole hydrogen production system can be divided into two processes: preheating and reforming hydrogen production.

[0044] The preheating process refers to preheating the entire ethanol catalytic reforming device to the temperature range required for hydrogen production by reforming through the ethanol oxidation reaction combined with electric auxiliary heating. First, the intelligent control module heats the catalytic reforming unit to above 100°C by electric heating. Subsequently, the solution pump and pressure and flow control device are controlled to adjust the inlet volume of the ethanol solution, the air flow rate, and the outlet gas pressure value to obtain a raw material gas with a high oxygen-to-alcohol ratio. This gas enters the catalytic device to undergo an exothermic oxidation reaction, and the electric heating power is gradually reduced. The temperature sensor monitors the temperature of the reaction bed. After reaching the required temperature, the oxygen-to-alcohol ratio is gradually reduced, and the heating power is further reduced. At this time, the electric heating only functions to maintain and supplement heat to stabilize the temperature fluctuation of the bed. The entire preheating process does not require manual control.

[0045] After preheating is completed, the hydrogen production process by reforming is entered, with the ethanol reforming hydrogen production reaction as the main process. According to the required oxygen-to-alcohol ratio and reaction pressure in the hydrogen production reaction, the intelligent control module controls the pressure value of the motorized backpressure valve. During the catalytic reforming process, the pressure sensor can continuously monitor the pressure inside the ethanol catalytic reforming hydrogen production unit and output the signal to the pressure and flow control module and the solution pump through the intelligent control unit to adjust the air outlet pressure and flow rate as well as the ethanol solution flow rate. If the monitored reaction pressure is smaller than the set pressure of the backpressure valve during the whole process, the air outlet pressure will be increased. When the pressure inside the ethanol catalytic reforming hydrogen production unit is greater than the set pressure of the backpressure valve, the adjustment stops, and the pressure inside the hydrogen production unit is maintained in the set pressure environment. The adjustment of the oxygen-to-alcohol ratio is affected by the air flow rate and the inlet volume of the ethanol solution, and the matching relationship is determined by the internal batching algorithm, and only the oxygen-to-alcohol ratio value needs to be manually input. This automatic pressure and oxygen-to-alcohol ratio adjustment system has the advantages of high automation, reducing the complex preheating process, and controllable parameter numerical values.

[0046] Figure 2 It is an ethanol reforming coupled hydrogen separation unit device with three-stage reforming hydrogen production and separation and purification, which can improve the raw material conversion rate, inhibit the concentration polarization phenomenon, and increase the hydrogen production rate. The ethanol reforming catalyst is loaded in the catalytic section and is not in direct contact with the palladium membrane. The area of the palladium membrane is adjusted and matched according to the hydrogen production amount of each section of the catalyst.

[0047] Figure 2 In the ethanol reforming coupled hydrogen separation unit, the vaporized bio-ethanol solution is mixed with air and flows through the inlet section. The gas velocity in the space of the gas distribution device is homogenized. After uniform gas distribution, the gas flow passes through the first stage of catalytic reforming. The mixed gas undergoes a reforming reaction with the catalyst, mainly the conversion of ethanol to intermediate substances. A small amount of hydrogen produced is separated and purified with a short palladium membrane tube, which promotes the forward progress of the reaction equilibrium. The unreacted raw materials and some intermediate products enter the next stage of catalytic reforming. The newly produced hydrogen is separated and purified by the palladium membrane tube again, and other gases enter the next stage, repeating the previous steps, and a total of three times of separation and purification are experienced.

[0048] The staged catalytic separation not only helps to promote the forward progress of the overall reaction and increase the hydrogen production per unit of ethanol, but also the segmented palladium membrane is beneficial to enhancing its own mechanical strength, being applicable to hydrogen separation under relatively high gas pressures, weakening the concentration polarization phenomenon caused by the growth of the surface concentration boundary layer of the palladium membrane, reducing the diffusion resistance of hydrogen on the surface of the palladium membrane, and improving the overall utilization efficiency of the palladium membrane.

[0049] As Figure 3a , which is the entire separation device. Its structural features are a honeycomb-shaped housing, and the internal channels are the main body of the palladium membrane tubes with their thickness increasing successively within the range of 20 mm - 40 mm. The cylinders are connected by non-hydrogen-permeable steel pipes. An unequal number of palladium membrane tubes are evenly distributed inside each housing. The lengths of the palladium membrane tubes on each housing are different and the flow channels are staggered from each other, increasing the flow field disturbance inside the reactor and weakening the concentration gradient of substances in the space. At the same time, it avoids the occurrence of flow dead zones of the reaction gas in the catalyst filling area and improves the catalyst utilization rate.

[0050] As Figure 3b , which is the segmentation of the separation device. After the gas flows through the catalytic section, part of the hydrogen is generated. The unseparated hydrogen in the upper section, the newly generated hydrogen, the unreacted raw material gas, and part of the intermediate products flow through the palladium membrane tubes. The hydrogen is separated by the palladium membrane tubes and accumulates inside the housing. The highly pure hydrogen enriched in each section is transported to the pure hydrogen outlet by the connecting pipes.

[0051] The beneficial effects of the present invention:

[0052] The segmented catalysis and separation and purification can promote the forward progress of the catalytic reforming reaction, greatly improving the conversion rate of ethanol and the hydrogen production. The segmented palladium membrane tubes enhance the mechanical strength by reducing their own structural dimensions and strengthen the potential of the reactor for pressurized reaction. It also effectively inhibits the concentration polarization phenomenon during the hydrogen separation process, reduces the radial mass transfer resistance, increases the hydrogen flux per unit area of the palladium membrane, and increases the hydrogen recovery rate. The automatic pressure regulating device has controllability, simplifies the complex process of catalyst preheating, enables the reaction to proceed under the set pressure and oxygen-to-ethanol ratio, and can monitor the pressure in real time and automatically adjust it when needed.

[0053] The key technical points of the present invention:

[0054] 1. A system concept for regulating the reaction bed pressure and the oxygen-to-ethanol ratio in the raw material gas, which can automatically adjust the reaction pressure, enabling the reaction to occur in a relatively stable high-pressure environment, increasing the pressure difference across the palladium membrane, and improving the separation and purification efficiency of hydrogen. The segmented multi-tube palladium membrane separation and purification is adopted to stage-separate the obtained hydrogen-rich gas, promoting the positive shift of the chemical reaction equilibrium and increasing the raw material conversion rate and hydrogen production.

[0055] 2. The segmented multi-tube palladium membrane is used for separation and purification, and the obtained hydrogen-rich gas is separated stage by stage, promoting the positive shift of the chemical reaction equilibrium, and improving the raw material conversion rate and hydrogen production. The palladium membrane flow channels are arranged in a staggered manner, strengthening the internal flow field disturbance and reducing the flow blind area. It effectively inhibits the enhancement of the concentration polarization phenomenon caused by the rapid growth of the concentration boundary layer on the palladium membrane surface during the hydrogen separation process. At the same time, the flow of gas at a relatively high velocity in the small flow channels can also inhibit the concentration polarization, thereby increasing the hydrogen flux per unit area.

[0056] 3. The palladium membrane flow channels are arranged in a staggered manner, strengthening the internal flow field disturbance and reducing the flow blind area. It effectively inhibits the enhancement of the concentration polarization phenomenon caused by the rapid growth of the concentration boundary layer on the palladium membrane surface during the hydrogen separation process. At the same time, the flow of gas at a relatively high velocity in the small flow channels can also inhibit the concentration polarization, thereby increasing the hydrogen flux per unit area.

[0057] As mentioned above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims. The information disclosed in the background art part of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art.

Claims

1. A small-scale ethanol high-pressure reforming hydrogen production device with a segmented structure, characterized in that, It includes a control unit and an ethanol catalytic reforming hydrogen production unit. The ethanol catalytic reforming hydrogen production unit includes an inlet pipe, a conical end cap, a circular cylinder body and its end cap arranged in sequence; A gas distribution device is provided at a position near the conical end cap at the front end of the circular cylinder body, a flat plate gas distribution grid is provided at a position near the end cap at the rear end of the circular cylinder body, a segmented hydrogen separation device is provided inside the circular cylinder body, and the segmented hydrogen separation devices are connected by a connecting pipe in the core part. A plurality of palladium membrane tubes are provided around the connecting pipe in the core part of each segmented hydrogen separation device; Each segmented hydrogen separation device is a purification section, and the cavity inside the circular cylinder body at its front end is a catalytic section; The outlet of the connecting pipe in the core part passing through the flat plate gas distribution grid and the end cap is the residue outlet; The outlet of the cavity behind the last segmented hydrogen separation device passing through the flat plate gas distribution grid and the end cap is the pure hydrogen outlet; The palladium membrane tubes of adjacent segmented hydrogen separation devices are arranged staggeredly.

2. The small ethanol high-pressure reforming hydrogen production device with a segmented type according to claim 1, characterized in that: The inlet pipe of the ethanol catalytic reforming hydrogen production unit is connected with a pressure and flow control module and a vaporization device. The pressure and flow control module is provided with an air inlet, and the vaporization device is connected with a solution pump of an ethanol solution; The residue outlet of the ethanol catalytic reforming hydrogen production unit is connected with an electric back pressure valve, and the exhaust gas outlet of the electric back pressure valve is connected with the vaporization device.

3. The small-scale ethanol high-pressure reforming hydrogen production device with a segmented type according to claim 2, wherein, The ethanol catalytic reforming hydrogen production unit is provided with a temperature sensor and a pressure sensor.

4. The small-scale ethanol high-pressure reforming hydrogen production device with a segmented type according to claim 3, characterized in that, The control unit is respectively connected with the pressure and flow control module, the vaporization device, the solution pump, the electric back pressure valve, the temperature sensor and the pressure sensor.

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