CN113816472A

CN113816472A - Photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device

Info

Publication number: CN113816472A
Application number: CN202111214869.2A
Authority: CN
Inventors: 向征晨; 陈华予; 陈达; 谢彤
Original assignee: China Jiliang University
Current assignee: China Jiliang University
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2021-12-21

Abstract

The invention belongs to the technical field of hydrogen energy preparation and environmental purification, and particularly relates to a photovoltaic-driven urea pollutant purification device for hydrogen production by water decomposition coupling. The device structure mainly comprises a photovoltaic power supply system, a cathode water decomposition hydrogen production chamber, an anode urea pollutant degradation chamber and a gas dryer, wherein the photovoltaic power supply system is composed of a photovoltaic cell and a silver connecting wire, the cathode water decomposition hydrogen production chamber is composed of an electrolytic tank, a hydrogen evolution catalyst electrode in the electrolytic tank and electrolyte, the anode urea pollutant degradation chamber is composed of the electrolytic tank, a urea oxidation catalyst electrode in the electrolytic tank and the electrolyte, a urea concentration detector is arranged, and the gas dryer is a molecular sieve dryer. The device has the advantages of high selectivity of urea oxidation reaction up to 99%, simple structure, convenient operation, low operation cost and strong practicability, and can efficiently and conveniently carry out hydrogen production and purification of urea-containing sewage.

Description

Photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device

Technical Field

The invention belongs to the technical field of hydrogen energy preparation and environmental purification, and particularly relates to a photovoltaic-driven urea pollutant purification device for hydrogen production by water decomposition coupling.

Background

Hydrogen energy is a clean energy with high energy density and zero carbon emission. The hydrogen energy replaces the traditional fossil fuel (coal, petroleum, natural gas and the like), can optimize the energy structure, furthest reduces the carbon emission, and promotes the realization of carbon neutralization. The photovoltaic electrocatalysis water decomposition hydrogen production is a clean hydrogen energy source which is converted from inexhaustible solar energy, and the conversion efficiency from the solar energy to the hydrogen energy is usually more than 10 percent, so that the hydrogen production method which is nearly zero in operation cost has the potential to bring huge economic benefits. Because the water oxidation reaction of the anode is the rate-limiting step in the kinetics of the water decomposition hydrogen production reaction, in order to further reduce the voltage required between the two electrodes, improve the current and further increase the hydrogen production per unit time, the replacement of the water oxidation reaction of the anode with other oxidation reactions with lower theoretical potential is an effective means.

Urea, also known as urea, has a theoretical oxidation potential of 0.37V, which is much lower than the potential for water oxidation (1.23V), and thus if the water splitting reaction is replaced by the urea oxidation reaction, the voltage driving the two-electrode reaction will be greatly reduced. In addition, in production and life, urea is a nitrogen fertilizer with the highest nitrogen content and is widely used in various soil environments. In the process of industrial production of urea, waste water containing urea is inevitably discharged, and excess urea left by improper fertilization in soil also permeates underground water to be discharged, so that environmental pollution is finally caused. The existing urea degradation method faces the problems of secondary environmental pollution and the like, so that an efficient and environment-friendly means is urgently needed in practical application to solve the urea pollution in water quality.

The electrochemical oxidation urea degradation reaction driven by the photovoltaic is not only a high-efficiency water purification method without secondary pollution, but also can be coupled with the water decomposition hydrogen production reaction driven by the photovoltaic, so that the bipolar reaction voltage of water decomposition is effectively reduced, and the solar energy is utilized to a greater extent. The hydrogen production and the pollutant degradation are carried out simultaneously, and double benefits of hydrogen energy production and environment purification are brought. Therefore, the device has important industrial application value.

Disclosure of Invention

The invention aims to provide a device driven by a photovoltaic cell and used for hydrogen production and urea pollutant degradation and purification.

The invention is realized by the following scheme:

the invention discloses a photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device which is characterized by comprising a photovoltaic power supply system, a cathode water decomposition hydrogen production chamber, an anode urea pollutant degradation chamber and a gas dryer; the photovoltaic power supply system consists of a photovoltaic cell and a silver connecting wire; the cathode water decomposition hydrogen production chamber and the anode urea pollutant degradation chamber are respectively positioned on the left side and the right side of the electrolytic bath and are separated by a proton exchange membrane, wherein the cathode water decomposition hydrogen production chamber is composed of a right side electrolytic bath, a hydrogen evolution catalyst electrode and electrolyte, the anode urea pollutant degradation chamber is composed of a left side electrolytic bath, a urea oxidation catalyst electrode and electrolyte, and a urea concentration detector is simultaneously arranged for monitoring the concentration of urea in the electrolyte; the gas dryer is a molecular sieve dryer.

The invention relates to a photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device, wherein a photovoltaic cell is a commercial silicon-based solar cell and comprises monocrystalline silicon, polycrystalline silicon and amorphous silicon solar cells.

According to the photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device, a cathode water decomposition hydrogen production chamber and an anode urea pollutant degradation chamber are separated by a proton exchange membrane and are respectively subjected to hydrogen production reaction through electrolysis and urea oxidation reaction, the water decomposition cathode hydrogen production chamber is sealed by a sealing cover, and generated hydrogen is led out through an air guide pipe.

The invention relates to a photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device, wherein a hydrogen evolution catalyst electrode is a commercial catalyst electrode and comprises a platinum-based electrode and a platinum-titanium alloy electrode. The urea oxidation catalyst electrode is a transition metal-based catalyst electrode.

As a further improvement of the invention, the photovoltaic cell can be connected in series and in parallel to increase the voltage between the two electrodes and the loop current, so that the photovoltaic electrocatalytic hydrogen production and urea degradation are realized to the greatest extent.

The invention has the advantages that: the device has a simple structure, uses inexhaustible solar energy as a driving force, uses water containing urea pollutants as a raw material, and can simultaneously achieve the dual effects of producing sustainable hydrogen energy and purifying urea sewage; because the selectivity of the transition metal-based catalyst to the urea oxidation reaction is as high as 99 percent, the competition of the water oxidation reaction can be effectively avoided; compared with electro-catalytic water decomposition driven by photovoltaic, the device needs smaller bipolar voltage, saves more energy and has high efficiency of converting solar energy into hydrogen and degrading urea; the electric catalytic effect can be fed back in real time by detecting the change of the urea concentration before and after the reaction; when the concentration of the urea reaches the emission standard, the water valve can be opened to discharge, and then urea sewage is injected into the anode chamber again to continue degradation. The device provides a new technology for efficiently and simultaneously realizing hydrogen production and urea decomposition by utilizing solar energy, and has important industrial application value.

Drawings

FIG. 1 is a schematic structural diagram of a photovoltaic-driven water-splitting hydrogen production-coupled urea pollutant purification device provided by the invention.

In the figure: the system comprises a photovoltaic power supply system 1, a 2-cathode water decomposition hydrogen production chamber, a 3-anode urea pollutant degradation chamber, a 4-gas dryer, a 5-silicon-based solar cell, a 6-silver lead, a 7-hydrogen evolution catalyst electrode, a 8-urea oxidation catalyst electrode, a 9-electrolyte, a 10-electrolytic cell, a 11-proton exchange membrane, a 12-sealing cover, a 13-gas guide pipeline, a 14-urea concentration detector and a 15-drain valve.

Detailed Description

For a further understanding of the contents, features and effects of the present invention, reference is made to the following examples, which are set forth in the following detailed description and are to be read in conjunction with the accompanying drawings:

fig. 1 shows a photovoltaic-driven water-splitting hydrogen production coupling urea pollutant purification device, which comprises a photovoltaic power supply system 1, a cathode water-splitting hydrogen production chamber 2, an anode urea pollutant degradation chamber 3 and a gas dryer 4; the silicon-based solar cell 5 receives solar radiation as an energy input end, is connected with a hydrogen evolution catalyst electrode 7 and a urea oxidation catalyst electrode 8 through a silver lead 6 for energy input, and an electrolyte 9 containing urea pollutants is injected into an electrolytic cell 10; the cathode water decomposition hydrogen production chamber 2 and the anode urea pollutant degradation chamber 3 are separated by a proton exchange membrane 11, hydrogen production and electrochemical oxidation urea degradation processes are respectively carried out on the left part and the right part of the electrolytic tank 10, and the cathode water decomposition hydrogen production chamber 2 is sealed by a sealing cover 12 and conveys the produced hydrogen to the outside of the hydrogen production chamber through an air guide pipeline 13; the produced hydrogen gas enters a gas drier 4 to remove entrained moisture; the anode urea pollutant degradation chamber 3 is provided with a urea concentration detector 14, after reaction for a period of time, the concentration of urea in the electrolyte of the anode chamber is detected by the urea concentration detector 14, after the indication value is stable, when the concentration value of urea in water is smaller and meets the discharge standard, a drain valve 15 is opened to discharge the treated liquid, then the sewage containing urea pollutants is supplemented to the electrolytic tank 10, and the next cycle of reaction is continued.

The above embodiments are merely to illustrate the present invention, are some embodiments of the present invention, are not all embodiments, and are not intended to limit the present invention. Various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention, and all equivalent technical solutions also fall within the scope of the invention, which is defined by the claims.

Claims

1. A photovoltaic-driven water decomposition hydrogen production coupling urea pollutant purification device is characterized by comprising a photovoltaic power supply system, a cathode water decomposition hydrogen production chamber, an anode urea pollutant degradation chamber and a gas dryer; the photovoltaic power supply system consists of a photovoltaic cell and a silver connecting wire; the cathode water decomposition hydrogen production chamber and the anode urea pollutant degradation chamber are respectively positioned on the left side and the right side of the electrolytic bath and are separated by a proton exchange membrane, wherein the cathode water decomposition hydrogen production chamber consists of a right side electrolytic bath, a hydrogen evolution catalyst electrode and electrolyte; the anode urea pollutant degradation chamber consists of a left electrolytic tank, a urea oxidation catalyst electrode and electrolyte, and is also provided with a urea concentration detector for monitoring the concentration of urea in the electrolyte; the gas dryer is a molecular sieve dryer.

2. The device for purifying urea pollutants through coupling hydrogen production by water splitting driven by photovoltaic as claimed in claim 1, wherein the photovoltaic cell is a commercial silicon-based solar cell comprising a monocrystalline silicon, a polycrystalline silicon and an amorphous silicon solar cell.

3. The photovoltaic-driven hydrogen production by water coupled urea pollutant purification device as claimed in claim 1, wherein the cathode hydrogen production by water splitting chamber and the anode urea pollutant degradation chamber are separated by a proton exchange membrane, and hydrogen production by electrolysis and urea oxidation are respectively carried out in two parts.

4. The photovoltaic-driven hydrogen production by water coupled urea pollutant purification device according to claim 1, wherein the cathode hydrogen production by water decomposition chamber is sealed by a sealing cover, and the generated hydrogen is led out by an air guide pipe.

5. The photovoltaic-driven hydrogen production by water splitting coupled urea pollutant purification device according to claim 1, wherein the hydrogen evolution catalyst electrode is a commercial catalyst electrode comprising a platinum-based electrode and a platinum-titanium alloy electrode, and the urea oxidation catalyst electrode is a transition metal-based catalyst electrode.