Technology for producing hydrogen and oxygen by electrolyzing unconventional water resources through new energy such as solar energy / wind energy

Abstract

The invention relates to a technology for producing hydrogen and oxygen by electrolyzing unconventional water resources through new energy such as solar energy / wind energy, and belongs to the field of new energy utilization and water treatment. The technical system comprises a wind energy / solar power generation system (S1), an energy storage system (S2), an electrolysis unit (S3), a hydrogen collection and storage system (S4), an oxygen collection and storage system (S5) and an intelligent allocation system (S6). The hydrogen and oxygen are directly stored through wind energy, solar energy and the like or stored through an energy storage facility and then used for electrolyzing wastewater such as sewage, tail water and mine pit gushing water, or blended water obtained after pretreatment of the wastewater or unconventional water resources such as tail water obtained after standard treatment to generate hydrogen and oxygen, and the hydrogen and the oxygen are collected and stored to serve as hydrogen energy and oxygen resources. On the whole, the intelligent allocation system allocates electric energy distribution, sewage pretreatment level and the like according to wind energy / solar energy generating capacity, electrolysis process energy demand, electrolysis water source instantaneous quantity, electrolysis water quality and the like. The system can realize reasonable utilization of unstable electric energy such as wind energy and solar energy, reduce sewage treatment cost, reduce tail water discharge and the like, and has application values of carbon pollution collaborative emission reduction and carbon sink increase.

Description

Technical Field

[0001] The present invention belongs to the field of new energy utilization and water treatment, and specifically relates to a technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy such as solar energy and wind energy. Background Art

[0002] With the advancement of the global energy transition, renewable energy sources such as wind and solar are being widely promoted as green and clean energy sources. However, due to natural environmental factors, these renewable energy sources exhibit significant temporal and spatial volatility and instability. This leads to difficulties in power regulation and curtailment when directly connected to the grid. Energy storage technology is considered a key path to addressing this challenge. Currently, mainstream energy storage technologies include pumped hydro, electrochemical energy storage, and compressed air energy storage. While these technologies offer advantages in different application scenarios, they also face the following limitations: First, pumped hydro has strict topographical requirements and is only suitable for mountainous areas with high and low elevations or in special geographical areas, restricting its large-scale deployment. Second, while electrochemical energy storage offers fast response and flexible regulation, it suffers from efficiency degradation, limited cycle life, and difficult battery thermal management. Furthermore, its production, decommissioning, and recycling processes are associated with certain environmental pollution. Third, some energy storage technologies still rely heavily on metal minerals or fossil materials in their manufacturing, which is inconsistent with the concept of green and low-carbon development. Therefore, the storage and utilization of new energy has become one of the key technical bottlenecks. Existing energy storage methods such as battery storage have problems such as high usage costs, poor renewable properties, and pollution in the production process. There is an urgent need to explore more sustainable energy storage conversion paths.

[0003] Currently, tailwater effluent quality requirements are becoming increasingly stringent. According to my country's environmental protection requirement that "discharge water quality should exceed the quality standards of receiving water bodies," tailwater in many regions must meet Class IV or even Class III surface water standards before discharge. This stringent requirement makes it difficult for traditional secondary treatment processes to meet discharge requirements, necessitating the addition of advanced treatment facilities such as reverse osmosis, ozone oxidation, and activated carbon adsorption, significantly increasing treatment costs. Furthermore, mine water inflows are another important unconventional water source. Mine water quality characteristics include high mineral content, wide pH variations, and high concentrations of heavy metal ions. The water quality varies significantly across mining areas and at different stages of mining, leading to significant fluctuations. While relatively mature, traditional physicochemical treatment processes such as neutralization sedimentation and coagulation clarification often face challenges with the complex and variable quality of mine water, including low treatment efficiency, high chemical consumption, and high sludge production. A comprehensive analysis reveals that existing treatment technologies for wastewater, tailwater, and mine water have significant technical limitations, necessitating the development of more efficient, cost-effective, and adaptable treatment technologies.

[0004] This technology uses electricity generated by solar / wind power generation systems to electrolyze unconventional water resources, including sewage, tailwater, mine water, pre-treated wastewater, or tailwater that meets standards. This technology can achieve goals such as reduced operating costs, renewable energy generation, and green, low-carbon production. Furthermore, it can reduce the amount of sewage or pre-treated water by electrolysis, thereby reducing the amount of sewage to be treated and thus lowering the cost of sewage treatment. Furthermore, by electrolyzing tailwater, it reduces the pressure on the environment to discharge wastewater. This technology not only enables the rational utilization of unstable electricity such as wind and solar energy, but also reduces sewage treatment costs and tailwater discharge, demonstrating its application value in synergistically reducing carbon emissions and increasing carbon sinks. Summary of the Invention

[0005] The purpose of the present invention is to provide a technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy such as solar energy and wind energy, so as to achieve the rational utilization of unstable electric energy such as wind energy and solar energy, reduce sewage treatment costs, and alleviate tail water discharge problems.

[0006] To achieve the above objectives, the present invention provides a technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy, which specifically includes a wind energy and solar energy power generation system (S1), an energy storage system (S2), an electrolysis unit (S3), a hydrogen collection and storage system (S4), an oxygen collection and storage system (S5), and an intelligent allocation system (S6);

[0007] The S1 wind / solar power generation system includes a wind power generation system, a solar power generation system, or a wind / solar combined power generation system, and the generated electricity is used as energy for water electrolysis;

[0008] The S2 energy storage system is used to store the surplus electric energy generated by S1 that exceeds the power demand of the electrolysis unit, and serves as a backup power supply to the electrolysis unit when the electric energy generated by S1 is insufficient to meet the operation of the electrolysis unit;

[0009] The S3 electrolysis unit uses the power supply of S1 as energy to electrolyze water to produce hydrogen and oxygen;

[0010] The electrolysis reaction is: Anode (oxygen evolution reaction, OER): 4OH⁻→O2↑+2H2O+4e⁻ Cathode (hydrogen evolution reaction, HER): 4H2O+4e⁻→2H2↑+4OH⁻ Overall reaction: 2H2O→2H2↑+O2↑

[0011] The water source used by the S3 electrolysis unit is sewage, tail water, mine water and other wastewater, or the water prepared after pre-treatment of wastewater, or tail water after standard treatment and other unconventional water resources;

[0012] The S4 and S5 collect hydrogen and oxygen generated by electrolysis of S3;

[0013] The S6 adjusts power distribution, sewage pretreatment level, etc. online and in real time according to wind / solar power generation, energy demand of the electrolysis process, instantaneous amount of electrolyzed water source, and electrolyzed water quality.

[0014] The present invention also provides a technology application for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy such as solar energy and wind energy.

[0015] The present invention is beneficial in that:

[0016] This invention integrates the efficient utilization of new energy and the coordinated treatment of water resources by constructing an unconventional water-based electrolysis hydrogen and oxygen production system powered by renewable energy sources such as wind and solar energy. This technology converts highly volatile renewable energy, which is difficult to directly connect to the grid, into storable and transportable hydrogen and oxygen, enabling the rational use of unstable wind and solar energy and improving the energy efficiency of renewable energy.

[0017] The electrolyzed water used in this invention is sourced from unconventional water resources such as sewage, tailwater, and mine water. This method offers excellent comprehensive water resource utilization value and is particularly suitable for water-scarce regions or areas with restricted sewage and wastewater discharge. Furthermore, electrolysis can achieve partial water volume reduction, effectively reducing the processing load and operating costs of conventional sewage treatment systems, and enhancing the overall green and low-carbon nature of the treatment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of a technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy such as solar energy and wind energy provided by the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the technical solutions of the present invention are described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0020] Example 1

[0021] A technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy is achieved through the following steps:

[0022] A solar-electric-thermal synergistic electrolysis system is used to electrolyze the sewage treatment plant tail water pretreated in step one to produce oxygen and hydrogen. The solar-electric-thermal synergistic electrolysis system includes a solar photovoltaic-electrolysis integrated component and a thermal-electric synergistic control module.

[0023] Pre-treating the tail water of the sewage treatment plant, including three-stage filtration, reverse osmosis and ion exchange resin treatment, to reduce or remove impurities such as suspended solids, inorganic salt components, organic pollutants, biological pollutants, redox substances, specific anions and hardness factors, thereby improving electrolysis efficiency and product quality;

[0024] Among them, the three-stage filtration system is primary sand filtration (100μm), intermediate filtration (20μm) and precision filtration (2μm);

[0025] The reverse osmosis operating pressure was 2 MPa, the resin regeneration cycle was 36 hours, and the suspended solids in the tail water after pretreatment were 0.5 mg / L, 0.1 mg / L of trivalent iron ions, 1 mg / L of chloride ions, and the conductivity was 5 μS / cm.

[0026] The wastewater treatment plant tail water pretreated in step 1 is electrolyzed to produce oxygen and hydrogen using a solar-electric-thermal synergistic electrolysis system comprising a solar photovoltaic-electrolysis integrated component and a thermal-electric synergistic control module;

[0027] The principle of the photo-electric-thermal synergistic electrolysis system is to illuminate photovoltaic materials with sunlight, and the photon energy excites electron-hole pairs in the semiconductor, forming a photocurrent under the action of the built-in electric field. The direct current output by the photovoltaic module is directly supplied to the electrolyzer, eliminating the multi-stage energy conversion link of "photovoltaic → inverter → grid → rectifier → electrolyzer" in traditional water electrolysis hydrogen production.

[0028] Among them, the photovoltaic-electrolysis integrated component includes a transparent conductive substrate, a photovoltaic layer and a catalytic layer;

[0029] The material of the transparent conductive substrate is tin oxide (FTO) conductive glass with a transmittance of 95% and a surface resistance of 5 Ω / sq;

[0030] The photovoltaic layer material is a perovskite film with a thickness of 200nm deposited directly on the substrate;

[0031] The catalytic layer material is a titanium dioxide / iridium dioxide (TiO2 / IrO2) composite catalytic layer, where the distance between the photovoltaic film and the catalytic layer is 0.5 mm, and the output electrode of the photovoltaic film is directly connected to the electrolysis power supply;

[0032] The heat-electricity coordinated control module is used for waste heat recovery and graded utilization. It includes a ring heat pipe array, an adsorption chiller, and an inlet water preheater. The high-temperature outlet temperature of the heat pipe array is 75°C, which is used to drive the chiller. The chiller has a coefficient of performance (COP) of 0.8 and a cooling output of 5°C, meeting the cooling requirements of the electrolyzer. The medium-temperature outlet temperature of the heat pipe array is 50°C and is connected to the preheater to preheat the inlet water to 30°C.

[0033] The system is located in a plateau area at an altitude of 3,200 meters. Sunlight is abundant but water resources are scarce, making conventional tap water hydrogen production expensive. The effluent quality of the local sewage treatment plant fluctuates greatly, making it difficult to meet standards through direct discharge.

[0034] During the operation of the system, the solar-electric-thermal synergistic electrolysis system provides an average annual electricity output of approximately 4,200 MWh, all of which is used in the electrolysis process, and can produce approximately 65 tons of hydrogen and 520 tons of oxygen annually; the average removal rate of soluble COD in the tail water reaches 35%, the NH4⁺-N removal rate is about 30%, and the tail water volume is reduced by about 40%, effectively reducing the pressure of deep tail water treatment and improving the emission rate that meets the standards.

[0035] Example 2:

[0036] Wind power generation equipment (total installed capacity of 10 MW, annual power generation of 35 GWh) was used to power the wastewater treatment plant tailwater, pre-treating it according to the method of Example 1. The electrolyzer unit employed proton exchange membrane (PEM) water electrolysis technology. Two PEM electrolyzers (each producing 500 Nm³ / h of hydrogen) were installed, with a total installed power of 8 MW. Boron-doped diamond (BDD)-coated titanium-based electrodes were used as the electrode material, achieving a COD degradation efficiency of ≥90%. Operating parameters included a current density of 2.5 A / cm², an electrolysis efficiency of 72%, and a specific hydrogen production energy consumption of 4.8 kWh / Nm³. The hydrogen and oxygen collection and storage system included a hydrogen compression tank, an oxygen purification unit, and a buffer tank.

[0037] During the operation of the system, about 655.5 tons of hydrogen and about 5,244 tons of oxygen can be produced annually.

[0038] After the electrolytic residual liquid is adsorbed by activated carbon, the COD is 30.51 mg / L, the NH3-N is 1.58 mg / L, the recycling rate is 95%, and the remaining concentrated water crystallization salt residue is transported out as industrial raw materials.

[0039] Example 3:

[0040] The wastewater treatment plant's tailwater is pretreated using three-stage filtration, reverse osmosis, and ion exchange resins. The three-stage filtration system consists of primary sand filtration (80μm), secondary filtration (15μm), and fine filtration (0.5μm). The reverse osmosis operating pressure is 1.5 MPa, and the resin regeneration cycle is 24 hours. The electrolyzer unit utilizes proton exchange membrane (PEM) water electrolysis technology, with a boron-doped diamond (BDD)-coated titanium-based electrode at the anode and a platinum / carbon composite cathode. The current density is 3.0A / cm², the cell voltage is 2.8V, and the electrolysis efficiency is 75%.

[0041] The tail water parameters are as follows:

[0042] index Raw water concentration After preprocessing After electrolysis COD (mg / L) 120.54 70.45 34.84 <![CDATA[NH3-N(mg / L)]]> 25.76 22.78 1.89 Suspended solids (mg / L) 80.25 0.88 0.24 Chloride ions 146.47 37.54 1.98

Claims

1. A technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy, characterized in that: It includes wind / solar power generation system (S1), energy storage system (S2), electrolysis unit (S3), hydrogen collection and storage system (S4), oxygen collection and storage system (S5), and intelligent deployment system (S6).

2. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy according to claim 1 is characterized in that: The S1 wind / solar power generation system includes a wind power generation system, a solar power generation system, or a wind / solar combined power generation system, and the generated electricity is used as energy for water electrolysis.

3. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy according to claim 1 is characterized in that: The S2 energy storage system is used to store the surplus electric energy generated by S1 that exceeds the power demand of the electrolysis unit, and serves as a backup power supply to the electrolysis unit when the electric energy generated by S1 is insufficient to meet the operation of the electrolysis unit.

4. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy according to claim 1 is characterized in that: The S3 electrolysis unit uses the power supply of S1 as energy to electrolyze water to produce hydrogen and oxygen.

5. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy according to claim 1 is characterized in that: The water source used by the S3 electrolysis unit is sewage, tail water, mine water and other wastewater, or the prepared water after pre-treatment of wastewater, or tail water after standard treatment and other unconventional water resources.

6. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy such as solar energy and wind energy according to claim 1 is characterized in that: The S4 and S5 collect hydrogen and oxygen generated by electrolysis of S3.

7. The technology for producing hydrogen and oxygen by electrolyzing unconventional water resources using new energy sources such as solar energy and wind energy according to claim 1 is characterized in that: The S6 adjusts power distribution, sewage pretreatment level, etc. online and in real time according to wind / solar power generation, energy demand of the electrolysis process, instantaneous amount of electrolyzed water source, and electrolyzed water quality.

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