Hydrogen is a clean fuel because it produces only water and represents clean energy using renewable energy sources. It can be stored in a fuel cell that produces electricity using an electrochemical conversion device. Hydrogen is a source of revolutionary energy of the future, but its development is still very insignificant. Reasons: energy that is difficult to produce, profitability and precarious energy balance due to the energy-intensive nature of the structure. But this option of energy supply offers interesting prospects in terms of energy storage, especially when it comes to renewable sources.
Pioneers of fuel cells
The concept was effectively demonstrated by Humphrey Davy in the early nineteenth century. This was followed by the pioneering work of Christian Friedrich Schonbein in 1838. In the early 1960s, NASA, in collaboration with industry partners, began the development of this type of manned spacecraft. The result was the first PEMFC unit.
Another GE researcher, Leonard Nidrah, upgraded PEMFC Grubb using platinum as a catalyst. Grubb-Niedrach was further developed in collaboration with NASA and was used in the Gemini space program in the late 1960s. International Fuel Cells (IFC, later UTC Power) have developed a 1.5 kW Apollo space flight device. They provided electricity as well as drinking water for the astronauts during their mission. IFC subsequently developed 12 kW devices used to provide an on-board network on all spacecraft flights.
The car element was first invented by Grulle in the 1960s. GM used Union Carbide in an "Electrovan" car. It was used only as a company car, but could drive up to 120 miles on a full tank and reach speeds of up to 70 miles per hour. Kordesch and Grulke experimented with a hydrogen motorcycle in 1966. It was a hybrid element with a tandem NiCad battery, which reached an impressive 1.18 l / 100 km. This step has advanced e-bike technology and the commercialization of e-motorcycles.
In 2007, fuel sources became commercial in a wide range of areas; they began to be sold to end users with written warranties and service options, i.e. comply with the requirements and standards of a market economy. Thus, a number of market segments began to focus on demand. In particular, thousands of PEMFC and DMFC (APU) auxiliary power units have been commercialized in entertainment applications: boats, toys and training kits.
Horizon in October 2009 showed the first commercial electronic system Dynario, which runs on methanol cartridges. Horizon fuel cells can charge mobile phones, GPS systems, cameras, or digital music players.
Hydrogen production processes
Hydrogen fuel cells are substances that contain hydrogen as fuel. Hydrogen fuel is a zero-emission fuel that releases energy during combustion or through electrochemical reactions. Fuel cells and batteries produce electric current through a chemical reaction, but the former will generate energy as long as there is fuel, thus never losing charge.
Thermal processes with hydrogen production usually include steam reforming - a high-temperature process when steam reacts with a hydrocarbon source to produce hydrogen. Many natural fuels can be reformed to produce hydrogen.
Today, approximately 95% of hydrogen is obtained from gas reforming. Water is separated into oxygen and hydrogen by electrolysis, in a device that functions like Horizon zero fuel cells in the opposite direction.
Solar Based Processes
They use light as an agent to produce hydrogen. There are several processes based on solar panels:
- photobiological;
- photoelectrochemical;
- solar;
- thermochemical.
Photobiological processes use the natural photosynthetic activity of bacteria and green algae.
Photoelectrochemical processes are specialized semiconductors for the separation of water into hydrogen and oxygen.
Solar production of thermochemical hydrogen uses concentrated solar energy for the water separation reaction together with other species such as metal oxides.
Biological processes use microbes, such as bacteria and microalgae, and can produce hydrogen through biological reactions. In the microbial conversion of biomass, microbes destroy organic matter, such as biomass, while in photobiological processes, microbes use sunlight as a source.
Generation Components
Element devices are made of several parts. Each has three main components:
- anode;
- cathode;
- conductive electrolyte.
In the case of Horizon fuel cells, where each electrode is made of a high surface area material impregnated with a platinum alloy catalyst, the electrolyte material is a membrane and serves as an ionic conductor. Electrical generation is controlled by two primary chemical reactions. For elements using pure H 2 .
Hydrogen gas at the anode is split into protons and electrons. The former are passed through the electrolyte membrane, and the latter flow around it, generating an electric current. Charged ions (H + and e -) combine with O 2 at the cathode, releasing water and heat. The many environmental problems that affect the world today mobilize society to achieve sustainable development and progress in protecting the planet. Here, in the context, the key factor is the replacement of the actual basic energy resources with others that can fully satisfy human needs.
The elements under consideration are just such a device, thanks to which this aspect finds the most likely solution, since it is possible to obtain electric energy from pure fuel with high efficiency and without CO 2 emissions.
Platinum catalysts
Platinum is highly active for the oxidation of hydrogen and continues to be the most common electrocatalyst material. One of the main research areas of Horizon, where fuel cells are used with a reduced platinum content, is the automotive industry, where in the near future it is planned to use engineering catalysts made of platinum nanoparticles deposited on conductive carbon. These materials have the advantage of finely dispersed nanoparticles, high electrocatalytic surface area (ESA) and minimal particle growth at elevated temperatures, even at higher Pt loading levels.
Pt-containing alloys are useful for devices operating on specialized fuel sources such as methanol or reforming (H 2 , CO 2 , CO and N 2 ). Pt / Ru alloys showed improved performance compared to pure Pt electrochemical catalysts with respect to the oxidation of methanol and the absence of the possibility of carbon monoxide poisoning. Pt 3 Co is another catalyst of interest (especially for Horizon fuel cell cathodes); it has demonstrated increased oxygen reduction reaction efficiency as well as high stability.
The Pt / C and Pt 3 Co / C catalysts exhibit finely dispersed nanoparticles on surface carbon substrates. When choosing a fuel cell electrolyte, several key requirements are considered:
- High proton conductivity.
- High chemical and thermal stability.
- Low gas permeability.
Hydrogen energy
Hydrogen is the simplest and most common element in the universe. It is an important component of water, oil, natural gas and the entire living world. Despite its simplicity and abundance, hydrogen is rarely found in the natural gaseous state on Earth. It is almost always combined with other elements. And it can be obtained from oil, natural gas, biomass, or by separating water using solar or electric energy.
Once hydrogen is formed as molecular H 2 , the energy present in the molecule can be released through interaction with O 2 . This can be achieved either by internal combustion engines or by hydrogen fuel cells. In them, the energy of H 2 is converted into an electric current with low power losses. Thus, hydrogen is an energy carrier for moving, storing and delivering energy produced from other sources.
Power Module Filters
Obtaining alternative energy elements is impossible without the use of special filters. Classic filters help in the development of power modules of elements in different countries of the world due to high-quality blocks. Filters are supplied to prepare fuels, such as methanol, for use in cells.
Typically, applications for these power modules include power supply at remote locations, backup power for critical supplies, APUs on small vehicles, and offshore applications such as Project Pa-X-ell, which is a project for checking cells in passenger ships.
Stainless steel filter housings to solve filtration problems. In these demanding applications, zero dawn fuel cell manufacturers specify Classic Filters stainless steel filter housings for flexibility in production, higher quality standards, fast deliveries, and competitive prices.
Hydrogen Technology Platform
Horizon Fuel Cell Technologies was founded in Singapore in 2003, today it operates 5 of its international subsidiaries. The company's mission is to change the situation in fuel cells, working globally with the goal of rapid commercialization, lower technological costs and eliminating age-old hydrogen supply barriers. The company began with small and simple products that require a low amount of hydrogen, in preparation for larger and more complex applications. Following strict guidelines and a roadmap, Horizon has quickly become the world's largest volumetric element manufacturer below 1000 watts, serving customers in more than 65 countries with the widest selection of commercial products in the industry.
Horizon technology platform consists of: PEM - Horizon zero dawn fuel cells (microfuel and stacks) and their materials, hydrogen supply (electrolysis, reforming and hydrolysis), hydrogen storage devices and.
Horizon launched the world's first portable and personal hydrogen generator. HydroFill can generate hydrogen by decomposing water in a tank and storing it in HydroStick cartridges. They contain an absorbing hydrogen gas alloy that provides solid storage. The cartridges can then be inserted into the MiniPak charger, which can work with small fuel filter elements.
Horizon or home hydrogen
Horizon Technologies launches a hydrogen energy charging and storage system for home use, saving energy at home to charge portable devices. Horizon excelled in 2006 with the toy H-racer, a small car with a hydrogen element, recognized as the "best invention" of the year. Horizon offers decentralized energy storage at home thanks to its Hydrofill hydrogen charging station, which can recharge small, portable and reusable batteries. This hydrogen station requires only water to operate and generate energy.
Work can be provided by a network, solar panels or a wind turbine. From there, hydrogen is extracted from the station’s water tank and stored in solid form in small elements made of metal alloys. Hydrofill Station, priced at around US $ 500, is an avant-garde mobile phone solution. Where to find Hydrofill fuel cells at this price is not difficult for users, you just need to ask the appropriate request on the Internet.
Car hydrogen charging
Like battery powered electric cars, those that run on hydrogen also use electricity to drive the car. But instead of storing this electricity in batteries that take many hours to charge, the elements generate energy right on board the car, through the reaction of hydrogen and oxygen. The reaction proceeds in the presence of an electrolyte, a non-metallic conductor in which the electric current is carried by the movement of ions in devices where Horizon zero fuel cells are equipped with proton-exchange membranes. They function as follows:
- Hydrogen gas is supplied to the "-" anode (A) of the cell, and oxygen is directed to the positive pole.
- At the anode, the catalyst, platinum, discards the electrons of hydrogen atoms, leaving "+" ions and free electrons. Through the membrane located between the anode and cathode, ions pass exclusively.
- Electrons create an electric current, moving along an external circuit. At the cathode, electrons and hydrogen ions combine with oxygen to produce water flowing out of the cell.
So far, two things have hindered large-scale production of cars with a hydrogen engine: cost and hydrogen production. Until recently, a platinum catalyst that breaks down hydrogen into an ion and an electron has been overly expensive.
A few years ago, hydrogen fuel cells cost about $ 1,000 for every kilowatt of energy, or about $ 100,000 for a car. Various studies were conducted to reduce the cost of the project, including the replacement of the platinum catalyst with a platinum-nickel alloy, which is 90 times more efficient. Last year, the U.S. Department of Energy reported that the cost of the system dropped to $ 61 per kilowatt, which is still uncompetitive in the automotive industry.
X-ray computed tomography
This non-destructive testing method is used to study the structure of a two-layer element. Other methods commonly used to study structure:
- mercury intrusion porosimetry;
- atomic force microscopy;
- optical profilometry.
The results show that the porosity distribution has a solid basis for calculating thermal and electrical conductivity, permeability and diffusion. The measurement of the porosity of elements is very complex due to their thin, compressible and heterogeneous geometry. The result shows that porosity decreases with GDL compression.
The porous structure has a significant effect on mass transfer in the electrode. The experiment was carried out at various hot pressing pressures, which ranged from 0.5 to 10 MPa. Performance mainly depends on platinum metal, the cost of which is very high. Diffusion may increase due to the use of chemically binding agents. In addition, temperature changes affect the life time and average performance of an element. The degradation rate of high-temperature PEMFCs is initially low and then rapidly increasing. This is used to determine the formation of water.
Commercialization Issues
To be cost competitive, the cost of a fuel cell must be halved and the battery life similarly extended. However, today operating costs are still much higher since the cost of producing hydrogen is between $ 2.5 and $ 3, and the hydrogen supplied is unlikely to cost less than $ 4 / kg. In order for the cell to compete effectively with batteries, you should have a short charge time and minimize the battery replacement process.
Currently, the technology of using polymer fuel cells will cost $ 49 per kW for mass production (at least 500,000 units per year). However, in order to compete with internal combustion vehicles, automotive fuel cells must reach approximately $ 36 / kW. ( , ), , . , .
The cost of the stack depends on the material, technology and manufacturing techniques. The choice of material depends not only on the suitability of the material for functions, but also on manufacturability. Key tasks of the elements:
- Reducing the load on the electrocatalyst and increasing activity.
- Increased durability and reduced degradation.
- Optimization of electrode design.
- Improving the tolerance of impurities at the anode.
- Selection of materials for components. It is mainly based on value without sacrificing performance.
- System fault tolerance.
- The performance of an element depends mainly on the strength of the membrane.
The main GDL parameters that affect cell performance are reagent permeability, electrical conductivity, thermal conductivity, and mechanical support. GDL thickness is an important factor. A thicker membrane provides better protection, gives mechanical strength, has longer diffusion paths and more thermal and electrical resistance levels.
Progressive trends
Among the various types of elements, PEMFC adapts more mobile applications (cars, laptops, mobile phones, etc.), therefore, are of growing interest to a wide range of manufacturers. In fact, PEMFC has many advantages, such as low operating temperature, stable operation at high current density, low weight, compactness, potential for low cost and volume, long service life, fast startups and suitability for intermittent work.
PEMFC technology is well suited for various sizes and is also used with various fuels when they are properly processed to produce hydrogen. As such, it finds application from the small sub-watt scale, down to the megawatt scale. 88% of total shipments in 2016-2018 were PEMFC.