Based on hydrogen powered alkaline fuel cell technology, our technology offers an energy source that generates zero CO2 emissions with pure water as the only by-product, making it ideally suited for residential and small- to medium-sized power markets.
Full Answer
What is a hydrogen fuel cell?
A hydrogen fuel cell uses the chemical energy of hydrogen to produce electricity. It is a clean form of energy with electricity, heat and water being the only products and by-products. Fuel cells offer a variety of applications, from transportation to emergency back-up power, and can power systems as large as a power plant or as small as a laptop.
How do alkaline fuel cells work?
They are among the most efficient fuel cells, having the potential to reach 70%. NASA has used alkaline fuel cells since the mid-1960s, in the Apollo -series missions and on the Space Shuttle . The fuel cell produces power through a redox reaction between hydrogen and oxygen. At the anode, hydrogen is oxidized according to the reaction:
How does hydrogen fuel cell energy affect the environment?
When we consume the energy found in a hydrogen fuel cell, then the vast majority of the emissions that we create from that process involve water vapor and hot air. The primary expense that we pay in terms of greenhouse gas emissions comes from the fossil fuels needed to produce the fuel cell in the first place.
Are alkaline fuel cells the future of space power?
Alkaline fuel cells have been the primary source of electrical power on human spaceflight systems for over four decades. However, alkaline fuel cells use a costly, aging technology.
Why is the fuel cell described as an alkaline fuel cell?
Alkaline fuel cells use an alkaline electrolyte such as potassium hydroxide or an alkaline membrane that conducts hydroxide ions rather than protons.
What is an alkaline hydrogen oxygen fuel cell?
Alkaline fuel cells consume hydrogen and pure oxygen, to produce potable water, heat, and electricity. They are among the most efficient fuel cells, having the potential to reach 70%.
What is an alkaline fuel cell made of?
These are devices that, by definition, have an aqueous solution of sodium hydroxide or potassium hydroxide as the electrolyte. The fuel is almost always hydrogen gas, with oxygen (or oxygen in air) as the oxidizer.
How does an alkaline hydrogen oxygen fuel cell work?
A typical fuel cell works by passing hydrogen through the anode of a fuel cell and oxygen through the cathode. At the anode site, a catalyst splits the hydrogen molecules into electrons and protons.
How do you make an alkaline fuel cell?
In general form, a fuel cell consists of a porous anode and a porous cathode, with these two electrodes separated by a electrolyte. An oxidant is fed to the cathode to supply hydrogen while a fuel is fed in the anode to supply hydrogen....Results and Discussions.ComponentsCin (Kg)Cout (Kg)TOTAL170.00170.006 more rows
How does an alkaline fuel cell work chemistry?
Chemical Reactions in an Alkaline Fuel Cell. In AFCs, the oxygen reacts at the cathode to produce either hydroxide (OH-) or a carbonate ion (CO32-), depending upon the electrolyte composition. The ion travels through the electrolyte to react with hydrogen at the cathode.
What are the advantages of alkaline fuel cells?
Alkaline Fuel Cells (AFCs) are easy to handle, have very high electrical efficiency and are very suitable for dynamic operating modes. They can be built into small compact systems as well as in large power plants.
What is a hydrogen fuel cell made of?
A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode)—sandwiched around an electrolyte. A fuel, such as hydrogen, is fed to the anode, and air is fed to the cathode.
Are alkaline fuel cells are sensitive to co2?
KOH solution, the electrolyte in alkaline fuel cells, quickly reacts with carbon dioxide (CO2), forming potassium carbonate (K2CO3). Because of this, alkaline fuel cells typically operate on pure oxygen that is free from carbon dioxide (CO2).
What are the advantages and disadvantages of alkaline fuel cell?
Fuel Cell FAQs / Alkaline Fuel Cell (AFC) AFCs' high performance is due to the rate at which chemical reactions take place in the cell. They have also demonstrated efficiencies near 60% in space applications. The disadvantage of this fuel cell type is that it is easily poisoned by carbon dioxide (CO2).
What is a hydrogen fuel cell and how does it work?
How They Work. Fuel cell cars are powered by compressed hydrogen gas that feeds into an onboard fuel cell “stack” that doesn't burn the gas, but instead transforms the fuel's chemical energy into electrical energy. This electricity then powers the car's electric motors.
What type of energy is released by hydrogen fuel cells?
Electrical energyElectrical energy is released from hydrogen fuel cells. Electricity can be used to power a whole range of appliances and vehicles. The electricity in a fuel cell is created by applying hydrogen to the anode and oxygen to the cathode.
Where are alkaline fuel cells used?
Alkaline fuel cells (AFCs) are one of the most developed technologies and have been used since the mid-1960s by NASA in the Apollo and space shuttle programs. The fuel cells on board these spacecraft provide electrical power for onboard systems, as well as drinking water.
What are the different types of fuel cells?
Comparison of Fuel Cell TechnologiesFuel Cell TypeCommon ElectrolytePhosphoric acid (PAFC)Phosphoric acid soaked in a porous matrix or imbibed in a polymer membraneMolten carbonate (MCFC)Molten lithium, sodium, and/or potassium carbonates, soaked in a porous matrixSolid oxide (SOFC)Yttria stabilized zirconia2 more rows
What are the advantages and disadvantages of alkaline fuel cells?
Fuel Cell FAQs / Alkaline Fuel Cell (AFC) AFCs' high performance is due to the rate at which chemical reactions take place in the cell. They have also demonstrated efficiencies near 60% in space applications. The disadvantage of this fuel cell type is that it is easily poisoned by carbon dioxide (CO2).
What is a fuel cell GCSE?
A fuel cell is an electrochemical cell in which a fuel donates electrons at one electrode and oxygen gains electrons at the other electrode.
What is an alkaline fuel cell?
Alkaline fuel cells (AFCs) was one of the first extensively researched fuel cell types and was used by NASA for the Gemini , Apollo, and Space Shuttle missions. The first alkali electrolyte fuel cell was built by Francis Thomas Bacon (1904–1992) in 1939. He used potassium hydroxide for the electrolyte and porous “gas-diffusion” electrodes instead of the acid electrolytes and solid electrodes used in previous fuel cell prototypes. Like today’s fuel cells, Bacon also used pressurized gases to keep the electrolyte from “flooding” the electrodes. During World War II, he thought the alkali electrolyte fuel cell would provide a good source of power for the Royal Navy submarines instead of the dangerous storage batteries used at the time. For the next 20 years, he created large-scale demonstrations with his alkali cells using potassium hydroxide as the electrolyte. One of the first demonstrations was a 1959 Allis–Chalmers farm tractor that pulled a weight of 3000 pounds powered by a stack of 1008 alkaline cells. Allis–Chalmers continued fuel cell research for many years, and also demonstrated a fuel cell–powered golf cart, submersible vehicle, and forklift. In the late 1950s and 1960s, Union Carbide also experimented with alkali cells. Karl Kordesch and his colleagues designed alkali cells with carbon gas–diffusion electrodes based upon the work of G. W. Heise and E. A. Schumacher in the 1930s. They demonstrated a fuel cell–powered mobile radar set for the U.S. Army, as well as a fuel cell–powered motorbike. Pratt & Whitney licensed the Bacon patents in the early 1960s and won the National Aeronautics and Space Administration (NASA) contract to power the Apollo spacecraft with alkali cells.
What chemical reaction occurs in an alkaline fuel cell?
Chemical Reactions in an Alkaline Fuel Cell. In AFCs, the oxygen reacts at the cathode to produce either hydroxide (OH-) or a carbonate ion (CO32-), depending upon the electrolyte composition. The ion travels through the electrolyte to react with hydrogen at the cathode. AFCs use lower cost materials compared with other fuel cells.
What electrolyte is used in AFCs?
In AFCs that use immobile electrolyte, the KOH/H2O solution is held in an asbestos matrix. The electrolyte layer can be as thin as 0.05 mm; therefore, ohmic polarization is not as much of an issue in this type of AFC. The electrolyte typically used is 30-percent potassium hydroxide, which yields the optimal ionic conductivity when AFCs are operated at 60 to 80 C. Increasing the KOH concentration helps AFC performance, but it is not practical and feasible to use high concentrations of KOH in water due to the nonuniformity of KOH concentrations in operating cells. The oxygen reduction reaction may reduce the water concentration near the cathode and then the electrolyte solution may solidify, thus preventing reactant transport.
What are AFC electrodes made of?
The hydrophobic electrodes are carbon-based with PTFE, while the hydrophilic electrodes are usually made of metallic materials such as nickel and nickel-based alloys. The electrodes usually have several layers with different porosities for the liquid electrolyte, fuel, and oxidant. AFCs can use both precious and nonprecious metal catalysts. The precious metal catalysts used are platinum or platinum alloys that are deposited on carbon supports or manufactured on nickel-based metallic electrodes. The catalyst loading is typically 0.25 mg Pt/cm2 and up. The most commonly used nonprecious metal catalysts are Raney nickel for the anodes at a loading of 120 mg Ni/cm2, and silver-based powders for the cathodes with a loading between 1.5 to 2 mg Ag/cm2.
What are the requirements for fuel cell electrolytes?
As with other fuel cell types, the electrolyte must meet the following requirements: Finding an electrolyte material that meets all of these requirements is tough. The toughest requirements are high ionic conductivity, and a material that is stable in both an oxidizing and reducing environment.
How does hydrogen protons work in fuel cells?
In low temperature fuel cells, when the fuel in the fuel cell travels to the catalyst layer , the fuel molecule gets broken into protons (H+) and electrons. The electrons travel to the external circuit to power the load, and the hydrogen proton (ions) travel through the electrolyte until it reaches the cathode to combine with oxygen to form water.
What are fuel cells used for?
Fuel cells can be used for portable, backup, transportation, and stationary power applications. This article briefly describes some of these uses for fuel cells. Read More.
What is the effect of alkaline medium on fuel cells?
An alkaline medium also accelerates oxidation of fuels like methanol, making them more attractive. Less pollution results compared to acidic fuel cells.
What is the temperature of an alkaline fuel cell?
Alkaline fuel cells operate between ambient temperature and 90 °C with an electrical efficiency higher than fuel cells with acidic electrolyte, such as proton exchange membrane fuel cells (PEMFC), solid oxide fuel cells, and phosphoric acid fuel cells . Because of the alkaline chemistry, oxygen reduction reaction (ORR) kinetics at the cathode are much more facile than in acidic cells, allowing use of non- noble metals, such as iron, cobalt, or nickel, at the anode (where fuel is oxidized); and cheaper catalysts such as silver or iron phthalocyanines at the cathode, due to the low overpotentials associated with electrochemical reactions at high pH .
How does an electrolyte flow?
Flowing electrolyte designs use a more open matrix that allows the electrolyte to flow either between the electrodes (parallel to the electrodes) or through the electrodes in a transverse direction (the ASK-type or EloFlux fuel cell). In parallel-flow electrolyte designs, the water produced is retained in the electrolyte, and old electrolyte may be exchanged for fresh, in a manner analogous to an oil change in a car. More space is required between electrodes to enable this flow, and this translates into an increase in cell resistance, decreasing power output compared to immobilized electrolyte designs. A further challenge for the technology is how severe the problem of permanent blocking of the cathode is by K 2 CO 3; some published reports have indicated thousands of hours of operation on air. These designs have used both platinum and non-noble metal catalysts, resulting in increased efficiencies and increased cost.
How does carbonate affect water?
As well as these bulk effects, the effect on water management due to a change in vapor pressure and/or a change in electrolyte volume can be detrimental as well.
What are the elements that make up a fuel cell?
6. Electrolyte. 7. Anode. 8. Water. 9. Hydroxide Ions. The alkaline fuel cell (AFC), also known as the Bacon fuel cell after its British inventor, Francis Thomas Bacon, is one of the most developed fuel cell technologies.
What is the net reaction of hydroxide?
producing hydroxide ions. The net reaction consumes one oxygen molecule and two hydrogen molecules in the production of two water molecules. Electricity and heat are formed as by-products of this reaction.
How does a fuel cell work?
Chemistry. The fuel cell produces power through a redox reaction between hydrogen and oxygen. At the anode, hydrogen is oxidized according to the reaction: producing water and releasing electrons. The electrons flow through an external circuit and return to the cathode, reducing oxygen in the reaction: producing hydroxide ions.
Why are alkaline fuel cells so popular?
Because they are so well developed , alkaline fuel cells are currently the cheapest variant to manufacture.
How do hydrogen fuel cells work?
Fuel cells are a clean, emissions-free alternative to traditional combustion processes, and use hydrogen to generate energy via electrochemical reactions. These cells are made even more environmentally friendly when the hydrogen is produced via sustainable means. There are many variations in fuel cell ...
What is a fuel cell electric vehicle?
Fuel cell electric vehicles (FCEVs) are a major area of developmental focus, discussed frequently in popular media. These vehicles operate on fuel cell generated energy rather than standard combustion engine technology. FCEVs like the Toyota Mirai have competitive driving ranges compared to electric vehicles, and are very quick to refill.
What is phosphoric acid fuel cell?
Phosphoric acid fuel cells have utilized phosphoric acid as the electrolyte since their introduction in 1961. These cells are primarily used in stationary power generation applications, particularly those within an output power range of 100-400 kW. An advantage is their ability to handle high levels of impurities compared to PEMFCs.
What is a molten carbonate fuel cell?
Molten carbonate fuel cells (MCFCs) Molten carbonate fuel cells operate at high-temperatures like SOFCs, although they use a molten carbonate salt mixture electrolyte. MCFCs are being developed for electrical utility, military, and industrial applications.
Who invented the fuel cell?
The fundamental principle of the fuel cell was first proposed by Sir William Grove in 1838, and many deviations of the fuel cell have developed since then. Here we highlight some of the most prominent fuel cells and their respective applications.
What is the oldest fuel cell?
Alkaline fuel cells are the oldest commercialized fuel cell, first invented by Francis Bacon in 1932. AFCs contain porous electrodes saturated with alkaline solution that are separated by a hydroxide electrolyte. Since they are highly sensitive to CO 2, their reactions use pure oxygen or highly purified air. These are famous for their use by NASA in the 1960s to generate electricity and water for the crew of the Apollo and Space Shuttle programs. Because they are so well developed, alkaline fuel cells are currently the cheapest variant to manufacture.
How does a fuel cell work?
Image right: A fuel cell converts hydrogen and oxygen into water, producing electricity and heat in the process. It has two electrodes, the negative anode and positive cathode, separated by an electrolyte that only allows specific ion flows. Fuel is delivered to the anode and oxygen to the cathode. Credit: NASA.
What are the byproducts of hydrogen fuel?
With hydrogen fuel, heat and water are the only byproducts. With methanol fuel, heat and water are still the major byproducts, along with only a fraction of the carbon dioxide and none of the other pollutants produced by a gasoline-burning engine. Image left: Proton-exchange-membrane fuel cells are placed into long and short stacks to produce ...
What is the purpose of NASA Glenn's fuel cell research?
NASA Glenn's fuel cell research could lead to new flight capabilities, electric power for long-term human exploration beyond Earth orbit, more efficient cars and trucks, and a cleaner environment.
What is the purpose of proton exchange?
Image left: Proton-exchange-membrane fuel cells are placed into long and short stacks to produce the necessary amount of electricity. Credit: NASA. The NASA Glenn Research Center is the focal point for NASA's fuel cell research and development. Glenn helped to develop the alkaline fuel cells that are the primary source of power on ...
How many electrodes does a fuel cell have?
Like a battery, a fuel cell has two electrodes (a cathode and an anode) that are separated by an electrolyte. However, batteries have at least one solid metal electrode that is slowly consumed as electricity is produced. In a fuel cell, the electrode is not consumed, and the cell can produce electricity as long as more fuel ...
Is fuel cell energy good for the environment?
Fuel Cells: A Better Energy Source for Earth and Space. Producing power without damaging our environment is a continuing challenge. Fossil fuels like gasoline, coal, and jet fuel are not renewable, and burning these fuels increases air pollution and harms the enviroment. Batteries have limited lifetimes and need to be disposed ...
Can fuel cells be used in cars?
These improved fuel cells may soon be seen in many areas of our lives. For example, fuel cells may soon provide auxiliary equipment power on commercial aircraft. They could be used in cars, commercial powerplants, and personal electronics. Glenn is developing and investigating fuel cells for emissions-free aircraft, the International Space Station, reusable launch vehicles, a Mars airplane, and a Space Shuttle upgrade, as well as for systems to produce electricity and store energy on the Moon and Mars.
How do fuel cells work?
Fuel cells are similar to batteries in that they produce electricity without combustion or emissions. Unlike batteries, fuel cells do not run down or need to recharge —as long as there’s a constant source of fuel and oxygen. Compared to conventional gasoline vehicles, fuel cell vehicles can even reduce carbon dioxide by up to half if the hydrogen is produced by natural gas and by 90%, if the hydrogen is produced by renewable energy, such as wind and solar. There are also no pollutants emitted from the tailpipe—just water!
What are fuel cells used for?
Fuel cells can be used to power several applications. Hydrogen and fuel cells can be used in a broad range of applications. These range from powering buildings, cars, trucks, to portable electronic devices and backup power systems.
How far can a fuel cell go?
Similar to today’s gasoline vehicles, fuel cell electric cars can have a driving range of more than 300 miles on one tank of hydrogen fuel. They can refuel in just a few minutes and the fueling experience is almost identical to a gas station. Since the “engine” (i.e., fuel cell) has no moving parts, you’ll never need to change the oil. But because a fuel cell is more than twice as efficient as an internal combustion engine, a fuel cell car travels farther on that tank of hydrogen than a traditional car would on gasoline. This means you only need about half the amount of hydrogen, with double the fuel economy.
Why are fuel cells important?
Because fuel cells can be grid-independent, they’re also an attractive option for critical load functions such as data centers, telecommunications towers, hospitals, emergency response systems, and even military applications for national defense. 3. Fuel cells are a clean way to produce power.
What are the most abundant elements in fuel cells?
Here are five things to know about hydrogen and fuel cells. 1. Hydrogen is the most abundant element on earth. Hydrogen is an alternative fuel that has very high energy content by weight. It’s locked up in enormous quantities in water, hydrocarbons, and other organic matter.
How many hydrogen fuel stations are there in California?
There are more than 30 commercial hydrogen stations in California today. More than 30 public retail hydrogen fueling stations are online in California, with plans to install 100. There are also several stations ready to open up in the Northeast.
Do you need to change the oil in a fuel cell?
Since the “engine” (i.e., fuel cell) has no moving parts, you’ll never need to change the oil. But because a fuel cell is more than twice as efficient as an internal combustion engine, a fuel cell car travels farther on that tank of hydrogen than a traditional car would on gasoline.
What are the advantages of hydrogen fuel cells?
List of the Advantages of Hydrogen Fuel Cells. 1. It offers an effective method of energy storage. When energy is stored as hydrogen in the form of a liquid of gas, then it will not dissipate until it is used under the assumption that the fuel cell is properly constructed.
What is the main source of emissions from hydrogen fuel cells?
When we consume the energy found in a hydrogen fuel cell, then the vast majority of the emissions that we create from that process involve water vapor and hot air. The primary expense that we pay in terms of greenhouse gas emissions comes from the fossil fuels needed to produce the fuel cell in the first place.
How long does hydrogen fuel cell carbon debt last?
When we create a standard hydrogen fuel cell, then we create a carbon debt that can last for up to five years, depending on how often the technology is being used for energy.
How much has hydrogen gone down since 1990?
Although the installation cost of pipeline construction, shipping, and tanker movement for hydrogen have all gone down by up to 90% since the 1990s when fuel cells were first becoming available, there are still significant expenses to pay when installing the infrastructure necessary for this technology.
Why is hydrogen used in NASA?
Because it is such a high energy resource, NASA has used liquid hydrogen as a fuel since the 1970s. Now we are looking at the advantages and disadvantages of hydrogen fuel cells to see if they would be useful in other vehicles or situations.
How much does hydrogen lose from boiling off?
When you look at the normal rate of loss from boiling off with hydrogen, an outcome of 20% or lower is not unusual. As you introduce the manufacturing processes needed to create the fuel cell, then the losses can peak at 50%. It is expected to lose at least 1% of your overall product for every day of transportation required with this resource. That means our only option is to build manufacturing facilities that are close to our production resources to reduce the amount of total loss.
What happens when you combine oxygen and hydrogen?
When you combine one oxygen and two hydrogen, for example, you will get water. We can also find hydrogen in several organic compounds that we use for fuel today. These items are called “hydrocarbons,” and they make up most of what we use for heating, driving, and similar needs.
What is fuel cell?
A fuel cell is a kind of machine. As such, it is not unlike an electric water pump, a dynamo, or the combustion engine of a car. Just like all these engines, it is made to couple two processes: the first drives a second desired process. In an electric water pump, for instance, we make use of the power of electricity to drive the flow of water from a lower to a higher place. In a fuel cell, a chemical process drives an electrical one.
How does a fuel cell work?
A fuel cell uses a fuel such as hydrogen or methane, lets it react in a chemical reaction, and so powers an electric process. In the most basic type, a fuel cell uses hydrogen that reacts with oxygen, which produces water and leads to an electric tension that allows electricity to be “pumped” through wires and ap- pliances. This is very similar to what a battery does, with the difference that, in a fuel cell, the reacting substances are supplied, and the products of the reaction are removed continuously.
What are the arguments for fuel cell technology?
There are at least three arguments in favor of Fuel Cell and Hydrogen Technology (FCH-T): 1. The fuels currently used are mostly non-renewable. Coal, oil, and natural gas have been laid down in the Earth’s crust a very long time ago, and once used up, they won’t come back. 2. Burning the usual fuels creates substances that harm the environment in several ways. For example, they pollute the air we breathe and the water we drink. Most importantly, carbon dioxide produced by burning coal, oil, and natural gas is making our planet warmer at a rate that will not be ac- ceptable to future generations—and should not be acceptable to us. 3. From a physical and technical viewpoint, burning fuels is wasteful—pro- ducing heat is not what we should be doing. There are better ways, at least theoretically, from a basic scientific and engineering perspective, to use fuels.
How can we use the Sun to power our energy?
If we want the Sun to power electric processes, we can build a photovoltaic solar plant. We can also use winds or water flowing at the surface of our planet to drive wind or water turbines which then drive electric generators. Since, on Earth, wind and water flows are caused by sunlight, the energy of wind and water lastly comes from the Sun as well. When we let electricity flow through lightly salted water, the water undergoes a chemical reaction that produces hydrogen and oxygen. The process is called elec- trolysis. Oxygen can be let into the atmosphere; hydrogen is collected and stored for any length of time desired. When hydrogen is needed, it can be fed into a fuel cell where the chemical reac- tion that produced it in the first place is reversed—water is produced from hydro- gen and oxygen which might be taken from the air. As a result, the fuel cell can
How many atoms are in hydrogen gas?
Hydrogen gas is composed of two hydrogen atoms. The symbol H is used for hydrogen (atoms), so hydrogen gas is denoted by H
What does burning hydrogen gas do?
Burning hydrogen gas means getting it into a chemical reaction with oxygen gas which produces water. Since water is composed of two parts of hydrogen and one part of oxygen (H
Why shouldn't we burn hydrogen?
Later we shall learn that there is another very important physical reason for not burning hydrogen: burning fuels creates heat, and creating heat is never a good solution to challenges in energy engineering. Rather, we should use fuels in fuel cells, especially if we desire electricity for fur- ther applications.
Overview
- There are a number of pros and cons associated with hydrogen fuel cells, the benefits include: 1. Durability 2. Energy Security 3. Fuel Flexibility 4. High Efficiencies 5. Low / Zero Emissions 6. Quiet Operation 7. Reliability 8. Scalability The challenges associated with fuel cells include:
Half Reactions
Electrolyte
Basic designs
The alkaline fuel cell (AFC), also known as the Bacon fuel cell after its British inventor, Francis Thomas Bacon, is one of the most developed fuel cell technologies. Alkaline fuel cells consume hydrogen and pure oxygen, to produce potable water, heat, and electricity. They are among the most efficient fuel cells, having the potential to reach 70%.
Advantages over acidic fuel cells
The fuel cell produces power through a redox reaction between hydrogen and oxygen. At the anode, hydrogen is oxidized according to the reaction:
producing water and releasing electrons. The electrons flow through an external circuit and return to the cathode, reducing oxygen in the reaction:
producing hydroxide ions. The net reaction consumes one oxygen molecule and two hydrogen m…
Commercial prospects
The two electrodes are separated by a porous matrix saturated with an aqueous alkaline solution, such as potassium hydroxide (KOH). Aqueous alkaline solutions do not reject carbon dioxide (CO2) so the fuel cell can become "poisoned" through the conversion of KOH to potassium carbonate (K2CO3). Because of this, alkaline fuel cells typically operate on pure oxygen, or at least purified air and would incorporate a 'scrubber' into the design to clean out as much of the carbon dioxide as …
See also
Because of this poisoning effect, two main variants of AFCs exist: static electrolyte and flowing electrolyte. Static, or immobilized, electrolyte cells of the type used in the Apollo space craft and the Space Shuttle typically use an asbestos separator saturated in potassium hydroxide. Water production is controlled by evaporation from the anode, which produces pure water that may be reclaimed for other uses. These fuel cells typically use platinum catalysts to achieve maximum v…
External links
Alkaline fuel cells operate between ambient temperature and 90 °C with an electrical efficiency higher than fuel cells with acidic electrolyte, such as proton exchange membrane fuel cells (PEMFC), solid oxide fuel cells, and phosphoric acid fuel cells. Because of the alkaline chemistry, oxygen reduction reaction (ORR) kinetics at the cathode are much more facile than in acidic cells, allowing use of non-noble metals, such as iron, cobalt, or nickel, at the anode (where fuel is oxidiz…