Fuel elements. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Alternative energy sources

 Comments on the article

The hydrogen-oxygen fuel cell was discovered in 1838 by the English scientist W. Grove. He investigated the decomposition of water into hydrogen and oxygen and found that an electrolyzer produced an electric current. It turned out that there are processes for converting fuel into electricity without burning the fuel. But mankind receives electricity mainly due to the combustion of oil, coal or gas in thermal power plants or nuclear fuel in nuclear power plants. Processes involving combustion come with large losses, so any options for generating electricity without burning fuel attracted scientists and engineers.

What is a fuel cell?

In the process of research, it turned out that fuel for fuel cells needs to be prepared. There is no pure hydrogen in nature. It has to be extracted from fossil fuels, such as methane or natural gas.

A fuel cell is a chemical current source and therefore consists of an anode, a cathode and an electrolyte (see figure).

The reducing agent (hydrogen) is oxidized at the anode, which donates electrons to the external circuit, and positively charged H+ ions enter the electrolyte. From the other end of the chain, the electrons approach the cathode, to which air (oxygen) is supplied, and a reduction reaction takes place (the addition of electrons by an oxidizing agent - oxygen). Positively charged hydrogen ions (protons) are carried by the electrolyte to the cathode, where they combine with negative oxygen ions to form water H2O.

Electrodes and electrolyte do not participate in the reaction. Thus, it is necessary to supply hydrogen and oxygen to the fuel cell, remove water and remove electric current.

Problems with hydrogen production led to attempts to use other reducing agents, in particular carbon monoxide CO, which is relatively easy to obtain from coal. In the 30s of the twentieth century. German researcher E. Bauer created a laboratory unit with a solid electrolyte for direct anodic oxidation of coal. Currently, in addition to coal, almost any organic fuel can be used. Instead of water in such fuel cells, the output product is carbon dioxide CO2.

Why are fuel cells attractive as a source of electricity?

First, they are more environmentally friendly than thermal power plants. Hydrogen-oxygen fuel cells produce water, while carbon-based fuel cells produce carbon dioxide, and much less per unit of electricity than thermal power plants.

Secondly, they have a high efficiency of about 40-60% (large thermal power plants have about 30%). Currently, technologies with efficiency up to 90% have been developed. This makes it possible to reduce the consumption of organic fuel by at least 2 times. Thirdly, the reliability of fuel is unusually high. The probability of failure-free operation is estimated at "seven nines" or 99,99999%.

Fuel cell types

These types are determined by the type of electrolyte used in fuel cells.

1. Phosphoric acid. This type of fuel cell is currently being mass-produced. They have already installed more than 200 - in hospitals, hotels, schools, offices. Their efficiency is 40%, but, in addition, the output product is also used - hot steam. The operating temperature in such fuel cells is about 200°C.

2. Proton exchange membranes. These elements operate at a lower temperature (about 100°C). Proton exchange membranes - a thin layer of plastic that allows protons to pass through. The plastic is coated on both sides with a layer of metal particles (most often platinum), which are an active catalyst. This type of fuel cells is considered the most promising for cars and as a replacement for batteries and accumulators.

3. Molten carbonate. Cells with this electrolyte operate at a temperature of about 700°C and can work with hydrogen, carbon monoxide, natural gas, propane, diesel fuel and other substances. Industrial installations with a capacity of 10 kW to 2 MW have been developed. Such fuel cells are promising as stationary power plants.

4. Solid oxides. Instead of a liquid electrolyte, a solid ceramic material is used. The operating temperature in such a fuel cell is up to 1000°C. The efficiency reaches 60%. A fuel cell with a power of 220 kW is demonstrated. Such fuel cells are promising as powerful power plants.

5. Alkaline electrolyte. Fuel cells with such an electrolyte (KOH) have long been used in US spacecraft. Their efficiency reaches 70%. But for commercial applications, they are still too expensive.

6. Methanol. Such an element is similar in structure to the element with a proton exchange membrane, but is built to extract hydrogen from liquid methanol. The efficiency is about 40%. Operating temperature 50-90°C.

7. Regenerative fuel cells. This type of fuel cell is under research. It uses a closed loop. Water is separated into hydrogen and oxygen by a solar cell electrolyser. Hydrogen and oxygen are fed into a fuel cell that produces electricity, heat and water. The water is recycled back to the electrolyzer and the process is repeated. This type of fuel cells is promising for spacecraft and stations.

See other articles Section Alternative energy sources.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Alcohol content of warm beer 07.05.2024

Beer, as one of the most common alcoholic drinks, has its own unique taste, which can change depending on the temperature of consumption. A new study by an international team of scientists has found that beer temperature has a significant impact on the perception of alcoholic taste. The study, led by materials scientist Lei Jiang, found that at different temperatures, ethanol and water molecules form different types of clusters, which affects the perception of alcoholic taste. At low temperatures, more pyramid-like clusters form, which reduces the pungency of the "ethanol" taste and makes the drink taste less alcoholic. On the contrary, as the temperature increases, the clusters become more chain-like, resulting in a more pronounced alcoholic taste. This explains why the taste of some alcoholic drinks, such as baijiu, can change depending on temperature. The data obtained opens up new prospects for beverage manufacturers, ... >>

Major risk factor for gambling addiction 07.05.2024

Computer games are becoming an increasingly popular form of entertainment among teenagers, but the associated risk of gaming addiction remains a significant problem. American scientists conducted a study to determine the main factors contributing to this addiction and offer recommendations for its prevention. Over the course of six years, 385 teenagers were followed to find out what factors may predispose them to gambling addiction. The results showed that 90% of study participants were not at risk of addiction, while 10% became gambling addicts. It turned out that the key factor in the onset of gambling addiction is a low level of prosocial behavior. Teenagers with a low level of prosocial behavior do not show interest in the help and support of others, which can lead to a loss of contact with the real world and a deepening dependence on virtual reality offered by computer games. Based on these results, scientists ... >>

Traffic noise delays the growth of chicks 06.05.2024

The sounds that surround us in modern cities are becoming increasingly piercing. However, few people think about how this noise affects the animal world, especially such delicate creatures as chicks that have not yet hatched from their eggs. Recent research is shedding light on this issue, indicating serious consequences for their development and survival. Scientists have found that exposure of zebra diamondback chicks to traffic noise can cause serious disruption to their development. Experiments have shown that noise pollution can significantly delay their hatching, and those chicks that do emerge face a number of health-promoting problems. The researchers also found that the negative effects of noise pollution extend into the adult birds. Reduced chances of reproduction and decreased fertility indicate the long-term effects that traffic noise has on wildlife. The study results highlight the need ... >>

Random news from the Archive Found a reliable way to transfer energy without wires 27.04.2022 A team of scientists from the US Naval Research Laboratory has tested a new technology for wireless power transmission. Using microwave radiation, physicists managed to transmit electricity with a power of 1,6 kilowatts over a distance of 1 kilometer at the US Army research site in Blossom Point (Maryland). The Laboratory emphasizes that this is the most successful and reliable demonstration of wireless power transmission in the last 50 years. Energy beams are transmitted between two points within the Safe and Continuous Power bEaming - Microwave (SCOPE-M) system. Special equipment converts electricity into microwaves, which are then focused by a narrow beam on a receiver with the so-called rectennas (rectifying antenna - rectifying antenna) - this is a special type of receiving antenna with high-frequency diodes. When microwaves hit the rectenna, they are converted into direct current. For 12 months, American scientists have tried using SCOPE-M to transmit electricity in the form of a microwave beam with a frequency of 10 GHz in two places - at the Blossom Point test site, as well as at the Haystack ultra-wideband satellite imaging radar transmitter at the Massachusetts Institute of Technology (MIT). The result in Maryland was 60% higher peak power, but Massachusetts was above average, resulting in more power in the end. Scientists do not want to use a higher microwave frequency, because this will lead to energy loss when passing through the atmosphere. The 10 GHz frequency allows the use of cheap and reliable components, while the power loss is less than 5% even in heavy rain.

Other interesting news:

▪ Volvo cars will warn each other about ice

▪ Lenovo IdeaPad Gaming Chromebook

▪ Large animals and deadly diseases

▪ Cheap drone that doesn't need fuel

▪ 42 V car batteries

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Experiments in chemistry. Article selection

▪ article Foreign literature of the XNUMXth century in brief. Crib

▪ article Where is the driest place on Earth? Detailed answer

▪ enema article. Health care

▪ article Processor automatic reset device in AON. Encyclopedia of radio electronics and electrical engineering

▪ article Competition of two pencils. physical experiment

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024