CN110010926A - A methanol-water reforming fuel cell system based on hydrogen peroxide reaction - Google Patents

Abstract

The embodiment of the present invention discloses a methanol water reforming fuel cell system based on hydrogen peroxide reaction, which is used to solve the technical problem that the heat transfer mode of the existing fuel cell system is too complicated. The embodiment of the present invention includes a stack, a pipeline, a reforming reactor, a first liquid storage tank for storing methanol aqueous solution, and a second liquid storage tank for storing hydrogen peroxide; the reforming reactor includes a methanol water inlet, Hydrogen outlet, oxygen outlet and hydrogen peroxide inlet; the outlet end of the first liquid storage tank is connected with a methanol pump, the outlet end of the methanol pump is connected with a pipeline, and the methanol pump is communicated with the methanol water inlet through the pipeline, so The hydrogen outlet is connected with the anode of the stack through a pipeline; the outlet end of the second liquid storage tank is connected with a hydrogen peroxide pump, the outlet end of the hydrogen peroxide pump is connected with a pipeline, and the hydrogen peroxide pump is connected with the hydrogen peroxide through the pipeline. The inlet is connected, and the oxygen outlet is connected with the cathode of the stack through a pipeline.

Description

A methanol-water reforming fuel cell system based on hydrogen peroxide reaction

technical field

The invention relates to the technical field of fuel cells, in particular to a methanol-water reforming fuel cell system based on hydrogen peroxide reaction.

Background technique

With the depletion of non-renewable resources such as fossil fuels, the future world energy system will gradually shift from non-renewable energy to renewable energy, reducing the dependence on traditional energy sources with high pollution and limited reserves (such as coal). At the same time, the storage and transportation of renewable energy, such as solar energy and wind energy, are inconvenient, and the chemical energy storage technology that uses hydrogen as a new energy fuel has high energy storage density and mature technology. At present, western developed countries have begun to establish hydrogen pipeline transportation networks. At the same time, fuel cell technology It is an internationally recognized key technology in the power generation link with the highest power generation efficiency and the lowest carbon emission.

Hydrogen has a wide range of uses in industry. In recent years, due to the rapid development of fine chemicals, bioengineering, petroleum refining and hydrogenation, and hydrogen fueled clean vehicles, the demand for hydrogen has increased rapidly, and the requirements for hydrogen production have also become higher and higher; In the regions of China, if the traditional gas production using petroleum, natural gas or coal as raw materials to separate hydrogen production requires huge investment, it is only suitable for large-scale users. Hydrogen can be easily produced by electrolysis of water for small and medium-sized users, but the energy consumption is very large, and the power consumption per cubic meter of hydrogen is 6 kWh. Therefore, in recent years, many manufacturers who originally used electrolyzed water to produce hydrogen have carried out technical transformations and switched to methanol steam reforming. A new process route for hydrogen.

Because hydrogen fuel is not easy to store, and its density is low, it is easy to leak, and it is easy to explode in case of fire. Its transportation and storage safety issues are very important. Generally, it is stored and transported in the form of compressed gas or cryogenic liquid (liquid hydrogen). Therefore, in-situ reforming of hydrogen production where it is needed (such as near miniature proton exchange membrane fuel cells) is a potentially energy-efficient and efficient method.

In the existing hydrogen production process, the initial energy consumption is relatively large, mainly generated by various forms of thermal energy heating and catalyzing hydrocarbon fuels. Since the current hydrogen production from hydrocarbon fuels requires a large volume of preheaters, the entire fuel cell system is caused. Overcomplicated.

Therefore, in order to solve the above-mentioned technical problems, finding a methanol-water reforming fuel cell system based on hydrogen peroxide reaction has become an important research topic for those skilled in the art.

SUMMARY OF THE INVENTION

The embodiment of the present invention discloses a methanol water reforming fuel cell system based on hydrogen peroxide reaction, which is used to solve the technical problem that the heat transfer mode of the existing fuel cell system is too complicated.

The embodiment of the present invention provides a methanol water reforming fuel cell system based on hydrogen peroxide reaction, including a stack, a pipeline, a reforming reactor, a first liquid storage tank for storing methanol aqueous solution, and a second liquid storage tank for storing hydrogen peroxide liquid storage tank;

The reforming reactor includes methanol water inlet, hydrogen outlet, oxygen outlet and hydrogen peroxide inlet;

The outlet end of the first liquid storage tank is connected with a methanol pump, the outlet end of the methanol pump is connected with a pipeline, the methanol pump is connected with the methanol water inlet through a pipeline, and the hydrogen outlet is connected with the electricity through a pipeline. The anodes of the stack are connected;

The outlet end of the second liquid storage tank is connected with a hydrogen peroxide pump, the outlet end of the hydrogen peroxide pump is connected with a pipeline, the hydrogen peroxide pump is connected with the hydrogen peroxide inlet through a pipeline, and the oxygen outlet is connected with the electrical outlet through a pipeline. The cathodes of the stack are connected.

Optionally, it also includes a hydrogen circulation pump;

The electric stack includes a hydrogen discharge port, the hydrogen discharge port is connected with the inlet end of the hydrogen circulation pump through a pipeline, and the outlet end of the hydrogen circulation pump is connected with the anode of the electric stack through a pipeline.

Optionally, a ball valve, a solenoid valve, a mass flow meter, and a check valve are sequentially connected between the methanol pump and the methanol water inlet through a pipeline.

Optionally, a ball valve, a solenoid valve, a mass flow meter, and a check valve are sequentially connected between the hydrogen peroxide pump and the hydrogen peroxide inlet through a pipeline.

Optionally, the reforming reactor includes an upper cover plate, a reforming reaction layer, a heat exchange layer, an exothermic reaction layer and a lower cover plate;

The methanol water inlet and the hydrogen outlet are both arranged on the upper cover plate, and the upper cover plate is also arranged with a carbon dioxide outlet;

The reforming reaction layer is provided with a first porous medium ceramic, and the first catalyst is placed in the first porous medium ceramic; the methanol water inlet, the hydrogen outlet, and the carbon dioxide outlet are all connected in the reforming reaction layer;

The exothermic reaction layer is provided with a second porous medium ceramic, and the second catalyst is placed in the second porous medium ceramic;

The hydrogen peroxide inlet and the oxygen outlet are all arranged on the lower cover plate, and the lower cover plate is also provided with a water outlet; the hydrogen peroxide inlet, the oxygen outlet, and the water outlet are all connected with the heat release. The reaction layers are connected.

Optionally, the first catalyst is copper and zinc oxide.

Optionally, the second catalyst is platinum.

Optionally, a heat exchanger is provided in the heat exchange layer, and the heat exchanger is used for transferring the heat in the exothermic reaction layer to the reforming reaction layer.

Optionally, a hydrogen permeable membrane is arranged between the upper cover plate and the reforming reaction layer.

Optionally, an oxygen-permeable membrane is arranged between the lower cover plate and the exothermic reaction layer.

As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

In this embodiment, the reforming reaction of methanol aqueous solution utilizes the heat generated by the catalytic reaction of hydrogen peroxide to provide heat, which can remove the original large heat exchanger, simplify the heat transfer mode of the fuel cell, and improve the heat transfer efficiency.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a schematic structural diagram of a methanol-water reforming fuel cell system based on hydrogen peroxide reaction provided in an embodiment of the present invention;

2 is a schematic structural diagram of a reforming reactor in a hydrogen peroxide reaction-based methanol-water reforming fuel cell system provided in an embodiment of the present invention;

Description: second liquid storage tank 1; hydrogen peroxide pump 2; first liquid storage tank 3; methanol pump 4; reforming reactor 5; hydrogen circulation pump 6; electric stack 7; ball valve 8; solenoid valve 9; mass flow meter 10; check valve 11; upper cover plate 12; reforming reaction layer 13; heat exchange layer 14; exothermic reaction layer 15; lower cover plate 16; hydrogen permeable membrane 17; heat exchanger 18; second catalyst 19; Oxygen permeable membrane 20; first catalyst 21; methanol water inlet 22; hydrogen outlet 23; carbon dioxide outlet 24; water outlet 25; oxygen outlet 26;

Detailed ways

The embodiment of the present invention discloses a methanol water reforming fuel cell system based on hydrogen peroxide reaction, which is used to solve the technical problem that the heat transfer mode of the existing fuel cell system is too complicated.

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, but not all, embodiments of 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 shall fall within the protection scope of the present invention.

Referring to FIG. 1 and FIG. 2 , an embodiment of a methanol-water reforming fuel cell system based on hydrogen peroxide reaction provided in an embodiment of the present invention includes:

The stack 7, the pipeline, the reforming reactor 5, the first liquid storage tank 3 and the second liquid storage tank 1, wherein the first liquid storage tank 3 is used to store methanol aqueous solution, and the second liquid storage tank 1 is used to store hydrogen peroxide;

The reforming reactor 5 includes a methanol water inlet 22, a hydrogen outlet 23, an oxygen outlet 26 and a hydrogen peroxide inlet 27;

The outlet end of the first liquid storage tank 3 is connected to the methanol pump 4 through the pipeline, and the outlet end of the methanol pump 4 is connected to the pipeline, and is communicated with the methanol water inlet 22 through the pipeline, and the methanol pump 4 pumps the methanol aqueous solution into the reforming reactor 5. The reforming reaction is carried out inside, thereby generating hydrogen gas. The hydrogen outlet 23 is connected to the anode of the stack 7 through a pipeline. The hydrogen is discharged from the hydrogen outlet 23 and enters the anode of the stack 7 through a pipeline.

The outlet end of the second liquid storage tank 1 is connected to the hydrogen peroxide pump 2 through a pipeline, and the outlet end of the hydrogen peroxide pump 2 is connected to a pipeline, and is communicated with the hydrogen peroxide inlet 27 through the pipeline, and the hydrogen peroxide pump 2 enters the hydrogen peroxide pump 2 into the reforming reactor 5. The exothermic reaction is carried out, and the hydrogen peroxide reacts with the catalyst to generate oxygen. The oxygen outlet 26 is connected to the cathode of the stack 7 through a pipeline. The oxygen is discharged from the oxygen outlet 26 and enters the cathode of the stack 7 through the pipeline.

In this embodiment, the reforming reaction of methanol aqueous solution utilizes the heat generated by the catalytic reaction of hydrogen peroxide to provide heat, and the original large heat exchanger 18 can be removed to simplify the heat transfer mode of the fuel cell and improve the heat transfer efficiency.

Further, this embodiment also includes a hydrogen circulation pump 6;

The stack 7 includes a hydrogen discharge port, the hydrogen discharge port is connected to the inlet end of the hydrogen circulation pump 6 through a pipeline, and the outlet end of the hydrogen circulation pump 6 is connected to the anode of the stack 7 through a pipeline.

It should be noted that the incompletely reacted hydrogen in the electrochemical reaction in the stack 7 is exported through the hydrogen circulation pump 6 and sent to the anode of the stack 7 again to realize anode recycling and improve the reaction efficiency of the stack 7 .

Further, in this embodiment, a ball valve 8 , a solenoid valve 9 , a mass flow meter 10 and a check valve 11 are connected in sequence between the methanol pump 4 and the methanol water inlet 22 through pipes.

A ball valve 8 , a solenoid valve 9 , a mass flow meter 10 , and a check valve 11 are connected in sequence between the hydrogen peroxide pump 2 and the hydrogen peroxide inlet 27 through pipes.

In this embodiment, the supply system is mainly divided into a methanol aqueous solution circuit and a hydrogen peroxide water circuit. The supply system has a liquid storage tank and a booster pump, and the control system includes a ball valve 8, a solenoid valve 9, a mass flow meter 10 and a check valve 11; In the reforming technology, the highest purity of hydrogen is obtained by the chemical reaction of steam, as shown in the reaction equation (1). ; There are hydrogen and carbon dioxide in the methanol reforming reaction product. At high temperature, methanol will partially crack to generate CO, but the CO content is extremely low. In order to prevent the poisoning of the Pt catalyst used later, the harmful gas CO needs to be removed by preferential oxidation. CO ₂ and H ₂ are separated by the hydrogen permeable membrane 17, CO ₂ is directly excluded from the system, and high-purity hydrogen enters the anode of the stack 7;

The reforming reaction of the methanol aqueous solution is an endothermic reaction, so it is necessary to continuously supply heat to the reaction vessel to maintain the chemical reaction rate. In this embodiment, the chemical reaction method is used to supply heat for the reforming, as shown in formula (2), which solves the defects of similar heating problems. For example, the energy conversion efficiency of electric heating is low, and the temperature point of combustion heating is not uniform. , and produce water vapor and oxygen. The water vapor and oxygen are separated by the oxygen permeable membrane 20. The water vapor can be passed into the methanol side as the raw material for the reforming reaction, and a part of the oxygen is generated for the preferential oxidation of CO. The remaining oxygen enters the cathode of the stack 7. The side is used as the reaction gas supply for the stack 7, and the insufficient gas inhales air from the surrounding atmosphere to keep the cathode side of the stack 7 in an oxygen-rich environment;

Since the amount of hydrogen peroxide remains relatively excessive, the temperature of hydrogen produced by methanol is basically the same as the reaction temperature. The high ^- temperature hydrogen carries part of the water vapor into the anode of the stack 7, which is used as the fuel of the fuel cell ^. After passing through the proton exchange membrane, it reaches the cathode side. At the same time, the oxygen on the cathode side also diffuses to the catalyst layer and is ionized into O ^2- , which reacts with the permeated H ⁺ to generate water. The electrons pass through the external circuit to generate electricity. The hydrogen is exported through the hydrogen circulation pump 6 and sent to the anode inlet again to realize anode recirculation and improve the reaction efficiency of the fuel cell;

Please refer to FIG. 2 , further, the reforming reactor 5 in this embodiment includes an upper cover plate 12 , a reforming reaction layer 13 , a heat exchange layer 14 , an exothermic reaction layer 15 and a lower cover plate 16 ;

The methanol water inlet 22 and the hydrogen outlet 23 are both arranged on the upper cover plate 12, and the upper cover plate 12 is also arranged with a carbon dioxide outlet 24;

The reforming reaction layer 13 is provided with a first porous medium ceramic, and the first catalyst 21 is placed in the first porous medium ceramic; the methanol water inlet 22, the hydrogen outlet 23, and the carbon dioxide outlet 24 are all connected to the reforming reaction layer 13;

A hydrogen permeable membrane 17 is arranged between the upper cover plate 12 and the reforming reaction layer 13;

The heat exchange layer 14 is provided with a heat exchanger 18, and the heat exchanger 18 is used for transferring the heat in the exothermic reaction layer 15 to the reforming reaction layer 13;

The exothermic reaction layer 15 is provided with a second porous medium ceramic, and the second catalyst 19 is placed in the second porous medium ceramic;

The hydrogen peroxide inlet 27 and the oxygen outlet 26 are all arranged on the lower cover plate 16, and the lower cover plate 16 is also provided with a water outlet 25; the hydrogen peroxide inlet 27, the oxygen outlet 26 and the water outlet 25 are all communicated with the exothermic reaction layer 15;

An oxygen-permeable membrane 20 is disposed between the lower cover plate 16 and the exothermic reaction layer 15 .

Further, the first catalyst 21 used in this embodiment is copper and zinc oxide; the second catalyst 19 is platinum, in addition to platinum, other metal catalysts can also be used, such as Fe, Cu, Cr, Pd, Mn can be.

The reforming reactor 5 in this embodiment is made of glass wafers and has certain chemical resistance. The heat exchanger 18 in this embodiment is a counter-flow heat exchanger 18, please refer to FIG. 2, which is divided into five parts. The first layer is the upper cover plate 12, which is provided with a methanol water inlet 22, a CO2 outlet and a H2 outlet, and the inside of the wafer is slotted with a hydrogen permeable membrane 17, which can realize the separation of carbon dioxide and hydrogen; the second layer is reforming The reaction layer 13, the catalyst is placed in the porous medium ceramic, the gas and liquid can pass through the porous medium, the porous medium ceramic is placed in the mouth of the second layer of the glass lens, and also plays an intermediate supporting role; the third layer is the heat exchange layer 14. The upper and lower surfaces of the heat exchanger 18 are in contact with the porous medium ceramics with catalysts, and fins can be added on the surface of the heat exchanger 18 to enhance the turbulent flow of the fluid and enhance the heat exchange effect; the fourth layer is The exothermic reaction layer 15, this layer also places the catalyst in the porous medium ceramic, and the porous medium ceramic also plays a supporting role; the fifth layer is the lower end plate, which is provided with a hydrogen peroxide inlet 27, an oxygen outlet 26 and a water vapor outlet, and the inner side of the wafer is The slot is equipped with an oxygen-permeable membrane 20, which can realize the separation of water vapor and oxygen.

In this embodiment, Cu and ZnO are selected as methanol steam reforming catalysts, wherein Cu provides catalytic activity, and ZnO is attached to the surface of Cu, and metal Pt is selected as catalyst for hydrogen peroxide decomposition;

During the exothermic reaction of hydrogen peroxide, the reformer is heated to about 250°C. At this time, the space velocity of hydrogen peroxide is high and the reaction is more violent. Then, water and methanol are mixed and fed into the reformer. The reforming reaction begins and the temperature begins to continue. At this time, the space velocity of methanol gradually increases, and the amount of hydrogen peroxide is started to be controlled to ensure that the temperature of the methanol side does not continue to rise and is controlled in a reasonable range. At this time, the space velocity of hydrogen peroxide and methanol obtained is a stable space velocity;

The electrical efficiency of PEMFC (Proton Exchange Membrane Fuel Cell) is between 40% and 60%, and the converted energy is released in the form of heat. This system uses methanol aqueous solution to cool the outside of the stack 7 system to avoid the occurrence of the inside of the stack 7. In case of overheating, most of the water produced by the reactor 7 reaction is discharged from the cathode, and this part of the water can be collected as deionized water;

The reforming reactor 5 in this embodiment is more compact than the existing similar reforming reactor 5, and the reaction heat release is more uniform. At the same time, the oxygen-rich environment enhances the system efficiency. The anode recirculation system of the stack 7 and the external The cooling system can ensure that the stack 7 is at a higher reaction efficiency.

In summary, the system has the following advantages:

1. The use of hydrogen peroxide exothermic reaction to heat methanol reforming simplifies the structure of the reforming reactor 5. The gasification reforming process does not require electric heating or combustion heating, which simplifies the system process, the heating temperature is more uniform and easy to control, and the fuel weight is improved. conversion efficiency;

2. The use of hydrogen peroxide to release heat can be used for the reuse of the reaction, and the generated water vapor is used as a raw material to participate in the reforming again, eliminating the traditional deionized water system;

3. The hydrogen and oxygen produced by the reforming system of this design are both wet and can carry water into the reactor 7 for reaction, canceling the traditional humidification system and simplifying the process flow;

4. The use of the hydrogen circulation pump 6 to realize the recirculation of the anode gas and the oxygen-rich environment of the cathode both improve the reaction efficiency of the stack 7;

5. The use of methanol solution to externally cool the stack 7 improves the safety of the system, and can regenerate and heat the methanol solution at the front to improve the cycle efficiency of the entire system.

6. The use of hydrogen peroxide to generate oxygen can preferentially oxidize the reforming harmful gas CO, prevent the poisoning of the catalyst of the stack 7, and improve the safety of the battery.

The above provides a detailed introduction to the methanol-water reforming fuel cell system based on the hydrogen peroxide reaction provided by the present invention. For those skilled in the art, according to the idea of the embodiment of the present invention, the specific implementation and application range will be There are changes. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A methanol water reforming fuel cell system based on hydrogen peroxide reaction, characterized in that, comprising a stack, a pipeline, a reforming reactor, a first liquid storage tank for storing methanol aqueous solution and a second storage tank for storing hydrogen peroxide liquid storage tank; The reforming reactor includes methanol water inlet, hydrogen outlet, oxygen outlet and hydrogen peroxide inlet; The outlet end of the first liquid storage tank is connected with a methanol pump, the outlet end of the methanol pump is connected with a pipeline, the methanol pump is connected with the methanol water inlet through a pipeline, and the hydrogen outlet is connected with the electricity through a pipeline. The anodes of the stack are connected; The outlet end of the second liquid storage tank is connected with a hydrogen peroxide pump, the outlet end of the hydrogen peroxide pump is connected with a pipeline, the hydrogen peroxide pump is connected with the hydrogen peroxide inlet through a pipeline, and the oxygen outlet is connected with the electrical outlet through a pipeline. The cathodes of the stack are connected. 2. The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 1, characterized in that, further comprising a hydrogen circulation pump; The electric stack includes a hydrogen discharge port, the hydrogen discharge port is connected with the inlet end of the hydrogen circulation pump through a pipeline, and the outlet end of the hydrogen circulation pump is connected with the anode of the electric stack through a pipeline. 3. The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 1, characterized in that, between the methanol pump and the methanol-water inlet, a ball valve, a solenoid valve, a mass flow rate valve are connected in sequence through a pipeline. Gauge, check valve. 4. The methanol water reforming fuel cell system based on hydrogen peroxide reaction according to claim 1, characterized in that, between the hydrogen peroxide pump and the hydrogen peroxide inlet, a ball valve, a solenoid valve, and a mass flow meter are sequentially connected through a pipeline. , Check valve. 5. The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 1, wherein the reforming reactor comprises an upper cover plate, a reforming reaction layer, a heat exchange layer, an exothermic reaction layer and lower cover; The methanol water inlet and the hydrogen outlet are both arranged on the upper cover plate, and the upper cover plate is also arranged with a carbon dioxide outlet; The reforming reaction layer is provided with a first porous medium ceramic, and the first catalyst is placed in the first porous medium ceramic; the methanol water inlet, the hydrogen outlet, and the carbon dioxide outlet are all connected in the reforming reaction layer; The exothermic reaction layer is provided with a second porous medium ceramic, and the second catalyst is placed in the second porous medium ceramic; The hydrogen peroxide inlet and the oxygen outlet are all arranged on the lower cover plate, and the lower cover plate is also provided with a water outlet; the hydrogen peroxide inlet, the oxygen outlet, and the water outlet are all connected with the heat release. The reaction layers are connected. 6 . The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 5 , wherein the first catalyst is copper and zinc oxide. 7 . 7 . The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 5 , wherein the second catalyst is platinum. 8 . 8 . The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 5 , wherein a heat exchanger is provided in the heat exchange layer, and the heat exchanger is used for converting the exothermic reaction layer into the heat exchanger. 9 . Heat is transferred to the reforming reaction layer. 9 . The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 5 , wherein a hydrogen permeable membrane is arranged between the upper cover plate and the reforming reaction layer. 10 . 10 . The methanol-water reforming fuel cell system based on hydrogen peroxide reaction according to claim 5 , wherein an oxygen-permeable membrane is arranged between the lower cover plate and the exothermic reaction layer. 11 .