阅读说明：本技术 用于光催化制氢的系统与方法 (System and method for photocatalytic hydrogen production ) 是由 马保军 宋旭东 于 2021-09-16 设计创作，主要内容包括：用于光催化制氢的系统和方法。系统包括依次经管线相连接的循环储液槽、循环泵和光催化反应器单元；其中,循环储液槽用于储存原料液；循环泵用于将来自循环储液槽的原料液泵送至光催化反应器单元以用于光催化制氢反应；光催化反应器单元包括至少1个光催化反应器组,光催化反应器组包括至少1个光催化反应器；光催化反应器包括由上至下依次连接设置的第一储液罐、催化剂分布板和第二储液罐,以及汽包；汽包设置于第二储液罐的顶部；第二储液罐至循环储液槽上还设置有循环管线。该系统和方法能够利用太阳光进行光催化反应实现甲醇制氢,提高制氢效率和制氢量,避免使用煤炭等不清洁能源。(Systems and methods for photocatalytic hydrogen production. The system comprises a circulating liquid storage tank, a circulating pump and a photocatalytic reactor unit which are sequentially connected through pipelines; wherein, the circulating liquid storage tank is used for storing the raw material liquid; the circulating pump is used for pumping the raw material liquid from the circulating liquid storage tank to the photocatalytic reactor unit for photocatalytic hydrogen production reaction; the photocatalytic reactor unit comprises at least 1 photocatalytic reactor group, and the photocatalytic reactor group comprises at least 1 photocatalytic reactor; the photocatalytic reactor comprises a first liquid storage tank, a catalyst distribution plate, a second liquid storage tank and a steam pocket which are sequentially connected from top to bottom; the steam pocket is arranged at the top of the second liquid storage tank; and a circulating pipeline is also arranged from the second liquid storage tank to the circulating liquid storage tank. The system and the method can utilize sunlight to carry out photocatalytic reaction to realize hydrogen production by methanol, improve the hydrogen production efficiency and the hydrogen production quantity, and avoid using unclean energy such as coal and the like.)

1. A system for photocatalytic hydrogen production is characterized by comprising a circulating liquid storage tank (2), a circulating pump (3) and a photocatalytic reactor unit (1) which are sequentially connected through pipelines; wherein the content of the first and second substances,

the circulating liquid storage tank (2) is used for storing raw material liquid; the raw material liquid comprises a mixed liquid of water and methanol;

the circulating pump (3) is used for pumping the raw material liquid from the circulating liquid storage tank (2) to the photocatalytic reactor unit (1) for photocatalytic hydrogen production reaction;

the photocatalytic reactor unit (1) comprises at least 1 photocatalytic reactor group comprising at least 1 photocatalytic reactor (11); the photocatalytic reactor (11) comprises a first liquid storage tank (111), a catalyst distribution plate (112), a second liquid storage tank (113) and a steam drum (114), which are sequentially connected from top to bottom;

the first liquid storage tank (111) is used for receiving the raw material liquid from the circulating pump (3) for photocatalytic hydrogen production reaction;

the catalyst distribution plate (112) forms an acute angle alpha with the vertical direction, and is provided with a plurality of liquid channels along the inclined direction of the catalyst distribution plate, and the liquid channels comprise inner channel walls positioned on the catalyst distribution plate (112) and outer channel walls far away from the catalyst distribution plate (112); the outer side channel wall of the liquid channel is a light-transmitting wall, and the inner side channel wall of the liquid channel is fixed with a photosensitive catalyst, so that raw material liquid from the first liquid storage tank (111) flows through the photosensitive catalyst to perform a photocatalytic hydrogen production reaction to obtain hydrogen and reaction liquid;

the second liquid storage tank (113) is used for receiving hydrogen and reaction liquid from the catalyst distribution plate (112);

the steam pocket (114) is arranged at the top of the second liquid storage tank (113) and is used for separating and storing hydrogen from the second liquid storage tank (113);

and a circulating pipeline (4) is also arranged from the second liquid storage tank (113) to the circulating liquid storage tank (2) and used for conveying the reaction liquid from the second liquid storage tank (113) to the circulating liquid storage tank (2) to be used as a part of the raw material liquid.

2. The system for photocatalytic hydrogen production according to claim 1, wherein the first liquid storage tank (111) is provided with a liquid outlet at a joint of a lower portion thereof and the catalyst distribution plate (112), the second liquid storage tank (113) is provided with a liquid inlet at a joint of an upper portion thereof and the catalyst distribution plate (112), and two ends of the liquid channel are respectively arranged corresponding to the liquid outlet and the liquid inlet.

3. The system for photocatalytic hydrogen production according to claim 1 or 2, wherein a plurality of strip-shaped reaction plates and a plurality of light-transmitting plates are arranged on the catalyst distribution plate (112) along the inclination direction of the catalyst distribution plate, and the strip-shaped reaction plates and the light-transmitting plates are buckled to form the liquid channel; the inner side channel wall is the strip-shaped reaction plate, and a photocatalyst is fixed on the inner side channel wall; the outer channel wall is the light-transmitting plate.

4. A system for photocatalytic hydrogen production according to any one of claims 1-3, characterized in that α -30-60 °.

5. The system for photocatalytic hydrogen production according to any one of claims 1-4, wherein the photocatalytic reactor group includes at least 2 photocatalytic reactors, and at least 2 of the photocatalytic reactors are arranged in series.

6. System for photocatalytic hydrogen production according to any of claims 1-5, characterized by that the photocatalytic reactor unit (1) comprises at least 2 photocatalytic reactor groups and that at least 2 of the photocatalytic reactor groups are arranged in parallel.

7. System for photocatalytic hydrogen production according to any of claims 1-6, characterized by that the circulation reservoir (2) is provided with an on-line formic acid analyzer for detecting the formic acid content of the liquid in the circulation reservoir (2).

8. A method for photocatalytic hydrogen production using the system of any one of claims 1-7, comprising the steps of:

(1) introducing a raw material liquid into the circulating liquid storage tank (2); the raw material liquid comprises a mixed liquid of methanol and water, wherein the amount of the water is 10-80 wt%;

(2) pumping the raw material liquid from the circulating liquid storage tank (2) to the first liquid storage tank (111) through the circulating pump (3);

(3) raw material liquid from the first liquid storage tank (111) flows through a photosensitive catalyst along a liquid channel on the catalyst distribution plate (112) under the action of gravity, and undergoes a photocatalytic hydrogen production reaction under the action of the photosensitive catalyst and sunlight, and hydrogen and reaction liquid are output to the second liquid storage tank (113);

(4) the hydrogen from the second liquid storage tank (113) is subjected to gas-liquid separation with reaction liquid through the steam drum (114) and is stored in the steam drum (114);

(5) and (3) recycling the reaction liquid obtained by the separation in the step (4) to the circulating liquid storage tank (2) to be used as a part of the raw material liquid.

9. The method according to claim 8, further comprising a step (6), wherein the step (6) is to detect the content of formic acid in the liquid in the circulating liquid storage tank (2), discharge the liquid until the conversion rate of methanol reaches 80-90 wt%, and supplement a mixed liquid of methanol and water.

10. The method of claim 8 or 9, wherein the photoactive catalyst is a non-noble metal catalyst, including WO₃Any one or more of a visible light photocatalyst, a CoP/TiO2 composite photocatalyst, and a coal-based W/WC composite catalyst.

Technical Field

The invention belongs to the field of photocatalytic hydrogen production, and particularly relates to a system and a method for photocatalytic hydrogen production.

Background

Under the background of carbon neutralization and carbon peak reaching, the carbon emission pressure in China is getting larger and larger, and hydrogen energy serving as an alternative energy can meet the requirement of national production. At present, technologies such as coal hydrogen production, biomass hydrogen production, natural gas hydrogen production and the like are developed vigorously, but the technologies all face the problem of carbon emission and cannot meet the basic requirement of clean hydrogen production, and the photocatalytic and electrocatalytic hydrogen production can avoid the utilization of carbon, so that the problem is solved fundamentally. At present, electrocatalytic hydrogen production is preliminarily industrialized, but the utilization and consumption of electric energy are also great resource waste, and photocatalytic hydrogen production can fully utilize inexhaustible energy such as solar energy, so that the method is the most promising hydrogen production technology. At present, photocatalytic hydrogen production is still in a catalyst development stage, and the efficiency is not high.

Disclosure of Invention

The invention aims to provide a system for photocatalytic hydrogen production, which has a simple structure, can realize the hydrogen production of methanol by utilizing sunlight to perform photocatalytic reaction, improves the hydrogen production efficiency and the hydrogen production quantity, and avoids using unclean energy sources such as coal and the like;

the second purpose of the invention is to provide a method for photocatalytic hydrogen production by using the system, which can realize the hydrogen production of methanol by using sunlight to perform photocatalytic reaction, improve the hydrogen production efficiency and the hydrogen production quantity, and avoid using unclean energy sources such as coal and the like.

In order to achieve the first purpose of the invention, the following technical scheme is adopted:

a system for photocatalytic hydrogen production comprises a circulating liquid storage tank, a circulating pump and a photocatalytic reactor unit which are sequentially connected through pipelines; wherein the content of the first and second substances,

the circulating liquid storage tank is used for storing raw material liquid; the raw material liquid comprises a mixed liquid of water and methanol;

the circulating pump is used for pumping the raw material liquid from the circulating liquid storage tank to the photocatalytic reactor unit for photocatalytic hydrogen production reaction;

the photocatalytic reactor unit comprises at least 1 photocatalytic reactor group, and the photocatalytic reactor group comprises at least 1 photocatalytic reactor; the photocatalytic reactor comprises a first liquid storage tank, a catalyst distribution plate, a second liquid storage tank and a steam drum which are sequentially connected from top to bottom;

the first liquid storage tank is used for receiving the raw material liquid from the circulating pump so as to be used for photocatalytic hydrogen production reaction;

the catalyst distribution plate forms an acute angle alpha with the vertical direction, and a plurality of liquid channels along the inclined direction of the catalyst distribution plate are arranged on the catalyst distribution plate, and each liquid channel comprises an inner channel wall positioned on the catalyst distribution plate and an outer channel wall far away from the catalyst distribution plate; the outer side channel wall of the liquid channel is a light-transmitting wall, and the inner side channel wall of the liquid channel is fixed with a photosensitive catalyst, so that raw material liquid from the first liquid storage tank flows through the photosensitive catalyst to perform photocatalytic hydrogen production reaction to obtain hydrogen and reaction liquid;

the second liquid storage tank is used for receiving the hydrogen and the reaction liquid from the catalyst distribution plate;

the steam pocket is arranged at the top of the second liquid storage tank and is used for separating and storing the hydrogen from the second liquid storage tank;

and a circulating pipeline is also arranged from the second liquid storage tank to the circulating liquid storage tank and used for conveying the reaction liquid from the second liquid storage tank to the circulating liquid storage tank to be used as a part of the raw material liquid.

The system for photocatalytic hydrogen production has a simple structure, can utilize the inexhaustible natural energy of sunlight to carry out photocatalytic reaction to realize the hydrogen production of methanol, and improves the hydrogen production efficiency and the hydrogen production quantity by recycling the reaction liquid, thereby realizing the continuity of industrial production; the use of unclean energy such as coal and the like is avoided, so that the problem of carbon emission is avoided; the use of electric energy is avoided, thereby avoiding the consumption of electric energy.

In one embodiment, a liquid outlet hole is formed at the joint of the lower part of the first liquid storage tank and the catalyst distribution plate, a liquid inlet hole is formed at the joint of the upper part of the second liquid storage tank and the catalyst distribution plate, and two ends of the liquid channel are respectively arranged corresponding to the liquid outlet hole and the liquid inlet hole so as to be respectively communicated with the first liquid storage tank and the second liquid storage tank.

In one embodiment, the catalyst distribution plate is provided with a plurality of strip-shaped reaction plates and a plurality of light-transmitting plates along the inclination direction of the catalyst distribution plate, and the strip-shaped reaction plates and the light-transmitting plates are buckled to form the liquid channels; the inner side channel wall is the strip-shaped reaction plate, and a photocatalyst is fixed on the inner side channel wall; the outer channel wall is the light-transmitting plate.

As understood by those skilled in the art, the light-transmitting plate is a groove-type plate, which is disposed in cooperation with the strip-type reaction plate, and the two plates can be fastened to each other to form a liquid channel.

Preferably, the light-transmitting plate is a quartz glass plate, so that sunlight can conveniently penetrate through the light-transmitting plate to carry out photocatalytic hydrogen production.

Preferably, α is 30 to 60 °, such as 35 °, 40 °, 45 °, 50 ° and 55 °, so that the raw material liquid flows slowly in the liquid channel under the action of gravity, and thus the raw material liquid flows slowly through the photosensitive catalyst in the liquid channel, and the photosensitive catalyst can be irradiated by sunlight sufficiently in a large area, so that the photosensitive catalyst can perform photocatalytic hydrogen production on the raw material liquid well.

In an embodiment, the photocatalytic reactor group comprises at least 2 photocatalytic reactors, and at least 2 photocatalytic reactors are arranged in series, so that the raw material liquid containing the mixed liquid of methanol and water is recycled, and the hydrogen production efficiency and the hydrogen production amount are improved.

Preferably, the group of photocatalytic reactors comprises 2-10 photocatalytic reactors, such as 3, 4, 5, 6, 7, 8 and 9.

In one embodiment, the system further comprises a gas storage tank connected to the drum for storing hydrogen gas from within the drum.

In one embodiment, the photocatalytic reactor unit comprises at least 2 photocatalytic reactor groups, and at least 2 photocatalytic reactor groups are arranged in parallel, so that the hydrogen production efficiency and the hydrogen production amount are improved, and a large amount of hydrogen can be obtained in a short time.

Preferably, the photocatalytic reactor unit comprises 2-10 photocatalytic reactor groups, such as 3, 4, 5, 6, 7, 8 and 9.

In one embodiment, an online formic acid analyzer is arranged on the circulating liquid storage tank and is used for detecting the formic acid content of the liquid in the circulating liquid storage tank, so that the liquid in the circulating liquid storage tank is discharged when the conversion rate of the methanol reaches 80-90 wt%, and a mixed liquid of the methanol and the water is re-injected to serve as a raw material liquid.

In order to achieve the second purpose of the invention, the following technical scheme is adopted:

a method for photocatalytic hydrogen production using the aforementioned system, the method comprising the steps of:

(1) introducing a raw material liquid into the circulating liquid storage tank; the raw material liquid comprises a mixed liquid of methanol and water, wherein the amount of the water is 10-80 wt%;

(2) pumping the raw material liquid from the circulating liquid storage tank to the first liquid storage tank through the circulating pump;

(3) raw material liquid from the first liquid storage tank flows through a photosensitive catalyst along a liquid channel on the catalyst distribution plate under the action of gravity, and undergoes a photocatalytic hydrogen production reaction under the action of the photosensitive catalyst and sunlight, and hydrogen and reaction liquid are output to the second liquid storage tank;

(4) the hydrogen from the second liquid storage tank is subjected to gas-liquid separation with the reaction liquid through the steam pocket and is stored in the steam pocket;

(5) and (4) recycling the reaction liquid obtained by the separation in the step (4) to the circulating liquid storage tank to be used as a part of the raw material liquid.

The method can utilize the inexhaustible natural energy of sunlight to carry out photocatalytic reaction to realize the hydrogen production of the methanol, thereby improving the hydrogen production efficiency and the hydrogen production quantity; the use of unclean energy such as coal and the like is avoided, so that the problem of carbon emission is avoided; the use of electric energy is avoided, thereby avoiding the consumption of electric energy.

Preferably, the method further comprises a step (6), wherein the step (6) is to detect the formic acid content of the liquid in the circulating liquid storage tank, discharge the liquid when the conversion rate of the methanol reaches 80-90 wt%, and supplement a mixed liquid of the methanol and water as a raw material liquid.

The person skilled in the art understands that methanol is converted into formic acid after photocatalytic hydrogen production reaction, and when the conversion rate is high and the content of methanol in the liquid in the circulating liquid storage tank is low, the methanol is used as a raw material liquid and is input into the first liquid storage tank, the hydrogen production efficiency is low, the hydrogen production amount is small, and therefore a mixed liquid of methanol and water needs to be added as the raw material liquid after being discharged.

Preferably, the photoactive catalyst is a non-noble metal catalyst, including WO₃Visible light photocatalyst, CoP/TiO₂Any one or more of a composite photocatalyst and a coal-based W/WC composite catalyst.

Preferably, said WO₃Visible light photocatalyst is WO disclosed by CN 107020080A₃Any one or more of visible light photocatalysts.

Preferably, the CoP/TiO₂The composite photocatalyst is CoP/TiO disclosed by CN105903482A₂Any one or more of a plurality of composite photocatalysts.

Preferably, the coal-based W/WC composite catalyst is any one or more of the coal-based W/WC composite catalysts disclosed in CN 108126722 a.

The invention has the beneficial effects that:

the system and the method for photocatalytic hydrogen production can utilize the inexhaustible natural energy of sunlight to carry out photocatalytic reaction to realize the hydrogen production of methanol, thereby improving the hydrogen production efficiency and the hydrogen production quantity; the use of unclean energy such as coal and the like is avoided, so that the problem of carbon emission is avoided; the use of electric energy is avoided, thereby avoiding the consumption of electric energy.

Drawings

FIG. 1 is a schematic diagram of a system for photocatalytic hydrogen production according to one embodiment of the present invention;

fig. 2 is a schematic structural diagram of a system for photocatalytic hydrogen production according to another embodiment of the present invention.

Detailed Description

The technical solution and the effects of the present invention will be further explained with reference to the accompanying drawings and the detailed description. The following embodiments are merely illustrative of the present invention, and the present invention is not limited to the following embodiments or examples. Simple modifications of the invention applying the inventive concept are within the scope of the invention as claimed.

As shown in fig. 1, the system for photocatalytic hydrogen production according to the present invention includes a circulation reservoir 2, a circulation pump 3, and a photocatalytic reactor unit 1, which are connected in sequence by a pipeline; wherein the content of the first and second substances,

the circulating liquid storage tank 2 is used for storing raw material liquid; the raw material liquid comprises a mixed liquid of water and methanol;

the circulating pump 3 is used for pumping the raw material liquid from the circulating liquid storage tank 2 to the photocatalytic reactor unit 1 for photocatalytic hydrogen production reaction;

the photocatalytic reactor unit 1 includes at least 1 photocatalytic reactor group including at least 1 photocatalytic reactor 11; the photocatalytic reactor 11 comprises a first liquid storage tank 111, a catalyst distribution plate 112, a second liquid storage tank 113 and a steam drum 114 which are sequentially connected from top to bottom;

the first liquid storage tank 111 is used for receiving the raw material liquid from the circulating pump 3 for photocatalytic hydrogen production reaction;

the catalyst distribution plate 112 has an acute angle α with the vertical direction, and is provided with a plurality of liquid channels along the inclined direction thereof, wherein the liquid channels comprise inner channel walls positioned on the catalyst distribution plate 112 and outer channel walls far away from the catalyst distribution plate 112; the outer channel wall of the liquid channel is a light-transmitting wall (for sunlight transmission), and the inner channel wall of the liquid channel is fixed with a photosensitive catalyst, so that raw material liquid from the first liquid storage tank 111 flows through the photosensitive catalyst to perform a photocatalytic hydrogen production reaction, and hydrogen and reaction liquid are obtained;

the second liquid storage tank 113 is used for receiving the hydrogen and the reaction liquid from the catalyst distribution plate 112;

the steam drum 114 is arranged at the top of the second liquid storage tank 113 and is used for separating and storing the hydrogen from the second liquid storage tank 113;

a circulating pipeline 4 is further arranged from the second liquid storage tank 113 to the circulating liquid storage tank 2, and is used for conveying the reaction liquid from the second liquid storage tank 113 to the circulating liquid storage tank 2 to be used as a part of the raw material liquid.

As understood by those skilled in the art, the photocatalyst is immobilized by a template curing technique, i.e., the photocatalyst is cured at a high temperature (200 ℃ C., 300 ℃ C., such as 210 ℃ C., 220 ℃ C., 230 ℃ C., 240 ℃ C., 250 ℃ C., 260 ℃ C., 270 ℃ C., 280 ℃ C., and 290 ℃ C.) after the multiple coating of the photocatalyst on the plate, thereby immobilizing the photocatalyst on the surface of the plate.

The invention fixes the photosensitive catalyst on the surface of the inner channel wall (equivalent to a flat plate) of the liquid channel, so that raw material liquid comprising the mixed liquid of water and methanol flows on the surface of the photosensitive catalyst, and the photocatalytic hydrogen production reaction is carried out under the irradiation of sunlight.

As understood by the technical personnel in the field, the steam drum utilizes the gravity action of the gas and the liquid to form forced circulation, so that the gas and the liquid are separated, and the hydrogen obtained by the photocatalytic hydrogen production reaction is collected.

The system for photocatalytic hydrogen production has a simple structure, can utilize the inexhaustible natural energy of sunlight to carry out photocatalytic reaction to realize the hydrogen production of methanol, and improves the hydrogen production efficiency and the hydrogen production quantity by recycling the reaction liquid, thereby realizing the continuity of industrial production; the use of unclean energy such as coal and the like is avoided, so that the problem of carbon emission is avoided; the use of electric energy is avoided, thereby avoiding the consumption of electric energy.

As understood by those skilled in the art, hydrogen production efficiency refers to the mass percentage of the actual amount of hydrogen produced relative to the theoretical amount of hydrogen produced.

In one embodiment, a liquid outlet is disposed at a connection position of the lower portion of the first liquid storage tank 111 and the catalyst distribution plate 112, a liquid inlet is disposed at a connection position of the upper portion of the second liquid storage tank 113 and the catalyst distribution plate 112, and two ends of the liquid channel are respectively disposed corresponding to the liquid outlet and the liquid inlet to respectively communicate with the first liquid storage tank 111 and the second liquid storage tank 113.

In one embodiment, the catalyst distribution plate 112 is provided with a plurality of strip-shaped reaction plates and a plurality of transparent plates along the inclined direction thereof, and the strip-shaped reaction plates and the transparent plates are fastened to form the liquid channels; the inner side channel wall is the strip-shaped reaction plate, and a photocatalyst is fixed on the inner side channel wall; the outer channel wall is the light-transmitting plate.

As understood by those skilled in the art, the strip-shaped reaction plate is a rectangular reaction plate; the light-transmitting plate is a groove-shaped plate, the groove-shaped plate is matched with the strip-shaped reaction plate, and the groove-shaped plate and the strip-shaped reaction plate can be mutually buckled to form a liquid channel.

In one embodiment, the strip reaction plate is a rectangular reaction plate of (1.5-2.5) m x (0.5-1.5) m, such as 2m x 1 m.

In one embodiment, α is 30 to 60 °, such as 35 °, 40 °, 45 °, 50 ° and 55 °, so that the raw material liquid flows slowly in the liquid channel under the action of gravity, and thus the raw material liquid flows slowly through the photosensitive catalyst in the liquid channel, and the photosensitive catalyst can receive the irradiation of sunlight in a large area, and thus the photosensitive catalyst can perform photocatalytic hydrogen production on the raw material liquid well.

As shown in fig. 2, in an embodiment, the photocatalytic reactor group includes at least 2 photocatalytic reactors, and at least 2 photocatalytic reactors are connected in series, so as to recycle a raw material liquid containing a mixed liquid of methanol and water, and improve hydrogen production efficiency and hydrogen production amount.

In one embodiment, the set of photocatalytic reactors comprises 2-10 photocatalytic reactors, such as 3, 4, 5, 6, 7, 8 and 9.

In one embodiment, the system further comprises a gas storage tank 5, said gas storage tank 5 being connected to said drum 114 for storing hydrogen gas from within said drum 114.

In one embodiment, the photocatalytic reactor unit 1 includes at least 2 photocatalytic reactor groups, and at least 2 photocatalytic reactor groups are arranged in parallel, so as to improve hydrogen production efficiency and hydrogen production amount, and obtain a large amount of hydrogen in a short time.

In one embodiment, the photocatalytic reactor unit 1 comprises 2-10 photocatalytic reactor groups, such as 3, 4, 5, 6, 7, 8 and 9.

In one embodiment, the light-transmitting plate is a quartz glass plate, so that sunlight can conveniently penetrate through the light-transmitting plate to carry out photocatalytic hydrogen production.

In one embodiment, an on-line formic acid analyzer is disposed on the circulation liquid storage tank 2, and is used for detecting the formic acid content of the liquid in the circulation liquid storage tank 2, so as to discharge the liquid in the circulation liquid storage tank 2 when the conversion rate of methanol reaches 80-90 wt%, and re-inject the mixed liquid of methanol and water as the raw material liquid.

A method for preparing hydrogen by photocatalysis by using the system comprises the following steps:

(1) introducing a raw material liquid into the circulating liquid storage tank 2; the raw material liquid comprises a mixed liquid of methanol and water, wherein the amount of the water is 10-80 wt%;

(2) the raw material liquid from the circulating liquid storage tank 2 is pumped to the first liquid storage tank 111 through the circulating pump 3;

(3) raw material liquid from the first liquid storage tank 111 flows through a photosensitive catalyst along a liquid channel on the catalyst distribution plate 112 under the action of gravity, and undergoes a photocatalytic hydrogen production reaction under the action of the photosensitive catalyst and sunlight, and hydrogen and reaction liquid are output to the second liquid storage tank 113;

(4) the hydrogen from the second liquid storage tank 113 is subjected to gas-liquid separation with the reaction liquid through the steam drum 114 and is stored in the steam drum 114;

(5) and (5) recycling the reaction liquid obtained by the separation in the step (4) to the circulating liquid storage tank 2 to be used as a part of the raw material liquid.

The method can utilize the inexhaustible natural energy of sunlight to carry out photocatalytic reaction to realize the hydrogen production of the methanol, thereby improving the hydrogen production efficiency and the hydrogen production quantity; the use of unclean energy such as coal and the like is avoided, so that the problem of carbon emission is avoided; the use of electric energy is avoided, thereby avoiding the consumption of electric energy.

In one embodiment, the method further comprises a step (6), wherein the step (6) is to detect the formic acid content of the liquid in the circulation liquid storage tank 2, discharge the liquid when the conversion rate of the methanol reaches 80-90 wt%, such as 82 wt%, 84 wt%, 86 wt% and 88 wt%, and supplement a mixed liquid of the methanol and the water as a raw material liquid.

The person skilled in the art understands that methanol is converted into formic acid after photocatalytic hydrogen production reaction, and when the conversion rate is high and the content of methanol in the liquid in the circulating liquid storage tank is low, the methanol is used as a raw material liquid and is input into the first liquid storage tank, the hydrogen production efficiency is low, the hydrogen production amount is small, and therefore a mixed liquid of methanol and water needs to be added as the raw material liquid after being discharged.

In one embodiment, the photoactive catalyst is a non-noble metal catalyst, including WO₃Visible light photocatalyst, CoP/TiO₂Any one or more of a composite photocatalyst and a coal-based W/WC composite catalyst.

In one embodiment, the WO is₃Visible light photocatalyst is WO disclosed by CN 107020080A₃Any one or more of visible light photocatalysts.

In one embodiment, the CoP/TiO is₂The composite photocatalyst is CoP/TiO disclosed by CN105903482A₂Any one or more of a plurality of composite photocatalysts.

In one embodiment, the coal-based W/WC composite catalyst is any one or more of the coal-based W/WC composite catalysts disclosed in CN 108126722 a.

The method of the invention not only fully utilizes renewable energy source-solar energy, avoids the use and investment of other energy sources, but also can improve the hydrogen production efficiency and the hydrogen production quantity, realizes industrial continuous production, and has great industrial value.

Example 1

When the method and the system shown in figure 1 are used for photocatalytic hydrogen production of methanol, the mixed solution of water and methanol is used as the raw material solution, wherein the water content is 50 wt%; the photosensitive catalyst used isCN105903482A CoP/TiO from example 1₂A composite photocatalyst;

200ml of raw material liquid is added into the circulating liquid storage tank 2, after photocatalytic hydrogen production is carried out, the obtained reaction liquid is recycled in the circulating liquid storage tank 2, the methanol conversion rate of the liquid in the circulating liquid storage tank 2 reaches 90 wt%, the hydrogen production amount can reach 1.5ml, and the hydrogen production efficiency is about 5%; it consumes only solar energy.

Example 2

Only the following differences from example 1 are present:

the photocatalyst used was WO 107020080A, example 3₃A visible light photocatalyst;

the methanol conversion rate of the liquid in the circulating liquid storage tank 2 reaches 92 wt%, the hydrogen production amount can reach about 1.7ml, and the hydrogen production efficiency is about 5.7%; it consumes only solar energy.

Example 3

When the method and the system shown in figure 2 are used for photocatalytic hydrogen production of methanol, the mixed solution of water and methanol is used as the raw material solution, wherein the water content is 50 wt%; the photo-sensitive catalyst used was CoP/TiO prepared in CN105903482A from example 1₂A composite photocatalyst;

respectively adding 200ml of raw material liquid into 5 circulating liquid storage tanks 2, and after photocatalytic hydrogen production is carried out on the raw material liquid, recycling the obtained reaction liquid into the circulating liquid storage tanks 2 until the methanol conversion rate of the liquid in the circulating liquid storage tanks 2 reaches 90 wt%, the hydrogen production amount reaches about 7.5ml, and the hydrogen production efficiency is about 5%; it consumes only solar energy.

Example 4

Only the following differences from example 3 are present:

the photocatalyst used was WO 107020080A, example 3₃A visible light photocatalyst;

the methanol conversion rate of the liquid in the circulating liquid storage tank 2 reaches 92 wt%, the hydrogen production amount can reach about 8.5ml, and the hydrogen production efficiency is about 5.7%; it consumes only solar energy.

Comparative example 1

Only the following differences from example 1 are present:

the circulation line 4 is not provided;

after the raw material liquid is subjected to photocatalytic hydrogen production, the obtained reaction liquid is not recycled;

the final hydrogen production amount is only 0.5ml, and the hydrogen production efficiency is about 2%; it consumes only solar energy.

Comparative example 2

Only the following differences from example 1 are present:

catalytic hydrogen production is carried out on 200ml of raw material liquid by adopting a Pt/CoP catalyst and adopting the traditional electrocatalytic hydrogen production;

the hydrogen production amount is only 0.5ml, and the hydrogen production efficiency is 2 percent; the consumption of the catalyst is electric energy, the whole consumption of the electric energy and the cost of the catalyst can reach more than twice of the cost of the photosensitive catalyst in the embodiment 1 to prepare the hydrogen.