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Ammonia energy storage #2

Recently, we reported on plans by Australian entrepreneurs and their government to use ammonia (NH3) to store excess wind energy. We proposed converting ammonia and CO2 from wastewater into methane gas (CH4), because it is more stable and easier to transport. The procedure follows the chemical equation:

8 NH3 + 3 CO2 → 4 N2 + 3 CH4 + 6 H2O

Now we have published a scientific article in the online magazine Frontiers in Energy Research where we show that the process is thermodynamically possible and does indeed occur. Methanogenic microbes in anaerobic digester sludge remove the hydrogen (H2) formed by electrolysis from the reaction equilibrium. As a result, the redox potentials of the oxidative (N2/NH3) and the reductive (CO2/CH4) half-reactions come so close that the process becomes spontaneous. It requires a catalyst in the form of wastewater microbes.

Pourbaix diagram of ammonium oxidation, hydrogen formation and CO2 reduction. At pH 7 and higher, the oxidation of ammonium coupled to methanogenesis becomes thermodynamically possible.

To prove our idea, we first searched for the right microbes that could carry out ammonia oxidation. For our experiments in microbial electrolysis cells we used microorganisms from sediments of the Atlantic Ocean off Namibia as starter cultures. Marine sediments are particularly suitable because they are relatively rich in ammonia, free from oxygen (O2) and contain less organic carbon than other ammonia-rich environments. Excluding oxygen is important because it used by ammonia-oxidizing microbes in a process called nitrification:

2 NH3+ + 3 O2 → 2 NO2 + 2 H+ + 2 H2O

Nitrification would have caused an electrochemical short circuit, as the electrons are transferred from the ammonia directly to the oxygen. This would have bypassed the anode (the positive electron accepting electrode) and stored the energy of the ammonia in the water − where it is useless. This is because, anodic water oxidation consumes much more energy than the oxidation of ammonia. In addition, precious metals are often necessary for water oxidation. Without producing oxygen at the anode, we were able to show that the oxidation of ammonium (the dissolved form of ammonia) is coupled to the production of hydrogen.

Oxidation of ammonium to nitrogen gas is coupled to hydrogen production in microbial electrolysis reactors. The applied potentials are +550 mV to +150 mV

It was important that the electrochemical potential at the anode was more negative than the +820 mV required for water oxidation. For this purpose, we used a potentiostat that kept the electrochemical potential constant between +550 mV and +150 mV. At all these potentials, N2 was produced at the anode and H2 at the cathode. Since the only source of electrons in the anode compartment was ammonium, the electrons for hydrogen production could come only from the ammonium oxidation. In addition, ammonium was also the only nitrogen source for the production of N2. As a result, the processes would be coupled.

In the next step, we wanted to show that this process also has a useful application. Nitrogen compounds are often found in wastewater. These compounds consist predominantly of ammonium. Among them are also drugs and their degradation products. At the same time, 1-2% of the energy produced worldwide is consumed in the Haber-Bosch process. In the Haber-Bosch process N2 is extracted from the air to produce nitrogen fertilizer. Another 3% of our energy is then used to remove the same nitrogen from our wastewater. This senseless waste of energy emits 5% of our greenhouse gases. In contrast, wastewater treatment plants could be net energy generators. In fact, a small part of the energy of wastewater has been recovered as biogas for more than a century. During biogas production, organic material from anaerobic digester sludge is decomposed by microbial communities and converted into methane:

H3C−COO + H+ + H2O → CH4 + HCO3 + H+; ∆G°’ = −31 kJ/mol (CH4)

The reaction produces CO2 and methane at a ratio of 1:1. Unfortunately, the CO2 in the biogas makes it almost worthless. As a result, biogas is often flared off, especially in places where natural gas is cheap. The removal of CO2 would greatly enhance the product and can be achieved using CO2 scrubbers. Even more reduced carbon sources can shift the ratio of CO2 to CH4. Nevertheless, CO2 would remain in biogas. Adding hydrogen to anaerobic digesters solves this problem technically. The process is called biogas upgrading. Hydrogen could be produced by electrolysis:

2 H2O → 2 H2 + O2; ∆G°’ = +237 kJ/mol (H2)

Electrolysis of water, however, is expensive and requires higher energy input. The reason is that the electrolysis of water takes place at a relatively high voltage of 1.23 V. One way to get around this is to replace the water by ammonium:

2 NH4+ → N2 + 2 H+ + 3 H2; ∆G°’ = +40 kJ/mol (H2)

With ammonium, the reaction takes place at only 136 mV, which saves the respective amount of energy. Thus, and with suitable catalysts, ammonium could serve as a reducing agent for hydrogen production. Microorganisms in the wastewater could be such catalysts. Moreover, without oxygen, methanogens become active in the wastewater and consume the produced hydrogen:

4 H2 + HCO3 + H+ → CH4 + 3 H2O; ∆G°’ = –34 kJ/mol (H2)

The methanogenic reaction keeps the hydrogen concentration so low (usually below 10 Pa) that the ammonium oxidation proceeds spontaneously, i.e. with energy gain:

8 NH4+ + 3 HCO3 → 4 N2 + 3 CH4 + 5 H+ + 9 H2O; ∆G°’ = −30 kJ/mol (CH4)

This is exactly the reaction described above. Bioelectrical methanogens grow at cathodes and belong to the genus Methanobacterium. Members of this genus thrive at low H2 concentrations.

The low energy gain is due to the small potential difference of ΔEh = +33 mV of CO2 reduction compared to the ammonium oxidation (see Pourbaix diagram above). The energy captured is barely sufficient for ADP phosphorylationG°’ = +31 kJ/mol). In addition, the nitrogen bond energy is innately high, which requires strong oxidants such as O2 (nitrification) or nitrite (anammox) to break them.

Instead of strong oxidizing agents, an anode may provide the activation energy for the ammonium oxidation, for example when poised at +500 mV. However, such positive redox potentials do not occur naturally in anaerobic environments. Therefore, we tested whether the ammonium oxidation can be coupled to the hydrogenotrophic methanogenesis by offering a positive electrode potential without O2. Indeed, we demonstrated this in our article and have filed a patent application. With our method one could, for example, profitably remove ammonia from industrial wastewater. It is also suitable for energy storage when e.g. Ammonia synthesized using excess wind energy.

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Fuel Cells

Fuel cells are a special type of galvanic cells. They can be fueled by solid, liquid, or gaseous fuel. The electrochemical oxidation of the fuel is coupled to energy gain, which is captured in form of electricity – as opposed to heat during chemical oxidation. Hence, fuel cells are direct energy converters with high efficiency. Most fuel cells achieve an energy conversion efficiency of 70-90%. If the conversion is 100%, no waste heat is produced. This ideal case of energy conversion is called ‘cold combustion’ which has been demonstrated for the first time in 1955 by Justi & Winsel. The fuel for this process is hydrogen gas, H2. It enters a porous nickel tube (gas diffusion electrode) where it is dissociated into protons and electrons according to:

H2 → 2 H+ + 2 e

Hydrogen fuel (H2) and oxygen (O2) are pumped into a fuel cell where two electrodes and the electrolyte fuse them to water.

During desorption, each H atom releases a proton (H+) and an electron (e). The electron is discharged onto the electrode, called anode, and the proton into the electrolyte. As a result of the dissociation process, the anode becomes negatively charged. On the second electrode, called cathode, oxygen gas, O2, is then charged with the electron and converted into O2− ions. The cathode becomes positively charged. Both electrodes are submerged in electrolytes which is in most cases a potassium hydroxide, KOH, solution of water. In the electrolyte, cations (H+) and anions (O2−) form water by chemical fusion. Theoretically, the efficiency is 92% accompanied by little waste heat – as opposed to normal combustion where heat of ~3,000ºC is produced.

2 H2 + O2 → H2O

Unlike heat power generators, fuel cells achieve high direct energy conversion efficiency because they avoid the additional step of heat generation. Besides shortcutting heat generation, fuel cells operate without mechanical parts and emit no noise, flue gas, or radioactivity, which puts them in focus of future developments. Due to their high energy efficiency and the high energy density of hydrogen, fuel cells are ideal for electric vehicles. In space flight, fuel cells were first used during Apollo Program between 1968 and 1972, in the Skylab Project 1973, the Apollo-Soyus Program, the Space Shuttle Program, and on board the International Space Station. There, they provide the electrical power for tools and water treatment. One benefit is that the final product of cold combustion in fuel cells is that water is the final product which is used by astronauts on their missions.

There are various types of fuel cells but all have in common that they consist of electrodes for fuel and O2 activation, and electrolytic conductors between these electrodes. Recent variations of fuel cells include methane fuel cells and microbial fuel cells. Due to the high activation energy of methane, methane fuel cells usually operate at high temperature using solid electrolytes. Microbial fuel cells, use microbes as anodic catalyst and organic matter in water as fuel. This makes them ideal for wastewater treatment.

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Nanomaterials in bio-electrical systems could improve performance

Since Professor Potter’s discovery of the ability of microbes to turn organic molecules into electricity using microbial fuel cells (MFC) more than a century ago (Potter MC, 1911, Proc Roy Soc Lond Ser B 84:260–276), much research was done to improve the performance. Unfortunately, this did not not produce an economically viable technology. MFCs never made it out of the professors’ class rooms. This may change now that we have advanced nanomaterials available.

The testing of nanomaterials in bio-electrical systems has experienced a Cambrian explosion. The focus usually was on electrodes, membranes, and in the electrolyte with infinite possibilities to find high performing composites. The benefits of such materials include a large surface area, cost savings, and scalability. All are required to successfully commercialize bio-electrical systems. The large-scale commercial application could be wastewater treatment. In our recently published literature survey we discovered that there is no common benchmark for performance, as it is usual in photovoltaics or for batteries. To normalize our findings, we used dollar per peak power capacity as ($/Wp) as it is standard in photovoltaics. The median cost for air cathodes of MFCs is $4,700 /Wp ($2,800 /m²). Platinum on carbon (Pt/C) and carbon nanofibers are the best performing materials with $500 /Wp (Pt/C $2,800 /m²; nanofibers $2,000 /m²).

We found that carbon-based nanomaterials often deliver performance comparable to Pt/C. While MFCs are still far away from being profitable, microbial electrolysis cells already are. With these new carbon-based nanomaterials, MFCs however, are moving closer to become an economic reality. Graphene and carbon nanotubes are promising materials when they are combined with minerals such as manganese or iron oxides. However, the price of graphene is still too expensive to let MFCs become an economic reality in wastewater treatment. The costs of microbial electrolysis, however, are already so low that it is a serious alternative to traditional wastewater treatment as we show in the featured image above. For high strength wastewater, a treatment plant can in fact turn into a power plant with excess power being offered to surrounding neighborhoods. Reducing the costs of microbial electrolysis is accomplished by using a combination of cheap steel and graphite.

Relationship between MEC reactor capacity and total electrode cost including anode and cathode. Errors are standard deviations of four different tubular reactor designs. Anodes are graphite granules and cathodes are steel pipes

 

Graphite, in turn, is the precursor of graphene, a promising material for MFC electrodes. When graphite flakes are reduced to a few graphene layers, some of the most technologically important properties of the material are greatly improved. These include the overall surface and the elasticity. Graphene is therefore a very thin graphite. Many manufacturers of graphene use this to sell a material that is really just cheap graphite. In the journal Advanced Materials Kauling and colleagues published a systematic study of graphene from sixty manufacturers and find that many high-priced graphene products consist mainly of graphite powder. The study found that less than 10% of the material in most products was graphene. None of the tested products contained more than 50% graphene. Many were heavily contaminated, most likely with chemicals used in the production process. This can often lead to a material having catalytic properties which would not have been observed without contamination, as reported by Wang and Pumera.

There are many methods of producing graphene. One of the simplest is the deposition on a metallic surface, as we describe it in our latest publication:

Single-layer graphene (SLG) and multilayer graphene (MLG) are synthesized by chemical vapor deposition (CVD) from a carbon precursor on catalytic metal surfaces. In a surface-mediated CVD process, the carbon precursor, e.g. Isopropyl alcohol (IPA) is decomposed on the metal surface, e.g. Cu or Ni. In order to control the number of graphene layers formed, the solubility of the carbon precursor on the metal catalyst surface must be taken into account. Due to the low solubility of the precursor in Cu, SLG can be formed. It is difficult to grow SLG on the surface of a metal with a high affinity for the precursor.

Protocol:
The protocol is a cheap, safe and simple method for the synthesis of MLG films by CVD in 30-45 minutes in a chemistry lab. A nickel foil is submersed in acetic acid for etching and then transferred to an airtight quartz tube. The same protects the system from ambient oxygen and water vapor. Nitrogen gas is bubbled through the IPA and the resulting IPA saturated gas is passed through the closed system. The exhaust gases are washed in a beaker with a water or a gas wash bottle. The stream is purged for 5 minutes at a rate of about 50 cc/min. As soon as the flame reaches a Meker burner 575-625 °C, it is positioned under the nickel foil, so that sufficient energy for the formation of graphene is available. The flame is extinguished after 5-10 minutes to stop the reaction and to cool the system for 5 minutes. The graphene-coated Ni foil is obtained.

But how thin must graphite flakes be to behave as graphene? A common idea supported by the International Organization for Standardization (ISO) is that flakes with more than ten graphene layers consist essentially of graphite. Thermodynamics say that each atomic layer in a flake with ten or fewer layers at room temperature behaves as a single graphene crystal. In addition, the stiffness of the graphite flakes increases with the layer thickness, which means that thin graphene flakes are orders of magnitude more elastic than thicker graphite flakes.

Unfortunately, to actually use graphene in bioelectric reactors, you still have to make it yourself. The ingredients can be found in our DIY Shop.

 
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An inexpensive scalable multi-channel potentiostat

As our preferred reader, you know already what we work on Power-to-Gas to combat Global Warming. We think that giving CO2 a value will incentivize its recycling and recycling it into fuel turns it into a commodity that everyone needs. While the price of CO2 from air is still too high to convert it into combustion fuel, working on the other end (the CO2 conversion) will help to accommodate such high prices. We have now published an research paper that shows how how to reduce the costs of electronic equipment needed for CO2 conversion. For Power-to-Gas as well es for electrosynthesis of liquid fuels, it is necessary to poise an electrochemical potential. So far, only electronic potentiostats could do that. We have developed a software solution that can control cheap off-the-shelf hardware to accomplish the same goal. Since the software controls µA as well as MA, it is freely scalable. By stacking cheap power supplies, it can also run unlimited channels.

Frontcell© potentiostat setup with two channels. From left to right: digital multimeter (in the back), relay board (in front), two H-type electrolysis cells, power supply, control computer.

We tested the software at a typical experimental Power-to-Gas setup at −800 mV and found that the recorded potential was stable over 10 days. The small electrochemical cells could also be replaced by a larger 7 liter reactor treating real wastewater. The potential was stable as well.

The potential of −800 mV controlled by the Frontcell© potentiostat was stable for 200 ml electrolysis cells (left) as well as for a larger 7 l reactor (right).

As instrument control of mass products also makes the chemical processes involved cheap, microbial electrolysis of wastewater becomes economically feasible. Removal of wastewater organics usually occurs at positive electrochemical potentials. Indeed, the software also stabilizes such potentials at +300 mV.

The Frontcell© potentiostat stabilized a 200 ml electrolysis cells at +300 mV for ten days.

The potentiostat is currently available as command line version. We are currently accepting pre-orders at a 50% discount for the commercial version that comes with a graphical user interface and remote control using an internet browser.

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Ammonia energy storage #1

The ancient, arid landscapes of Australia are not only fertile soil for huge forests and arable land. The sun shines more than in any other country. Strong winds hit the south and west coast. All in all, Australia has a renewable energy capacity of 25 terawatts, one of the highest in the world and about four times higher than the world’s installed power generation capacity. The low population density allows only little energy storage and electricity export is difficult due to the isolated location.

So far, we thought the cheapest way to store large amounts of energy was power-to-gas. But there is another way to produce carbon-free fuel: ammonia. Nitrogen gas and water are enough to make the gas. The conversion of renewable electricity into the high-energy gas, which can also be easily cooled and converted into a liquid fuel, produces a formidable carrier for hydrogen. Either ammonia or hydrogen can be used in fuel cells.

The volumetric energy density of ammonia is almost twice as high than that of liquid hydrogen. At the same time ammonia can be transported and stored easier and faster. Researchers around the world are pursuing the same vision of an “ammonia economy.” In Australia, which has long been exporting coal and natural gas, this is particularly important. This year, Australia’s Renewable Energy Agency is providing 20 million Australian dollars in funding.

Last year, an international consortium announced plans to build a $10 billion combined wind and solar plant. Although most of the 9 terawatts in the project would go through a submarine cable, part of this energy could be used to produce ammonia for long-haul transport. The process could replace the Haber-Bosch process.

Such an ammonia factories are cities of pipes and tanks and are usually situated where natural gas is available. In the Western Australian Pilbara Desert, where ferruginous rocks and the ocean meet, there is such an ammonia city. It is one of the largest and most modern ammonia plants in the world. But at the core, it’s still the same steel reactors that work after the 100 years-old ammonia recipe.

By 1909, nitrogen-fixing bacteria produced most of the ammonia on Earth. In the same year, the German scientist Fritz Haber discovered a reaction that could split the strong chemical bond of the nitrogen, (N2) with the aid of iron catalysts (magnetite) and subsequently bond the atoms with hydrogen to form ammonia. In the large, narrow steel reactors, the reaction produces 250 times the atmospheric pressure. The process was first industrialized by the German chemist Carl Bosch at BASF. It has become more efficient over time. About 60% of the introduced energy is stored in the ammonia bonds. Today, a single plant produces and delivers up to 1 million tons of ammonia per year.

Most of it is used as fertilizer. Plants use nitrogen, which is used to build up proteins and DNA, and ammonia delivers it in a bioavailable form. It is estimated that at least half of the nitrogen in the human body is synthetic ammonia.

Haber-Bosch led to a green revolution, but the process is anything but green. It requires hydrogen gas (H2), which is obtained from pressurized, heated steam from natural gas or coal. Carbon dioxide (CO2) remains behind and accounts for about half of the emissions. The second source material, N2, is recovered from the air. But the pressure needed to fuse hydrogen and nitrogen in the reactors is energy intensive, which in turn means more CO2. The emissions add up: global ammonia production consumes about 2% of energy and produces 1% of our CO2 emissions.

Our microbial electrolysis reactors convert the ammonia directly into methane gas − without the detour via hydrogen. The patent pending process is particularly suitable for removing ammonia from wastewater. Microbes living in wastewater directly oxidize the ammonia dissolved in ammonia and feed the released electrons into an electric circuit. The electricity can be collected directly, but it is more economical to produce methane gas from CO2. Using our technology, part of the CO2 is returned to the carbon cycle and contaminated wastewater is purified:

NH3 + CO2 → N2 + CH4

 

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Fuel Cells Have the Potential to Become the Best Green Energy Alternative to Fossil Fuels

Global warming is – as the name already suggests – a global concern. It causes problems such as sea level rise, more frequent and more severe strms, and longer droughts. Thus, it global warming concerns all of us. To best fight global warming, adopting green energy in your life is the best viable solution.

Green energy is getting more attention today. It helps to reduce our carbon footprint and thus curbing the global warming. Increasing carbon footprint is the main cause for rising temperatures. Moreover, investing in green energy is also a business case generating steady revenue stream without marginal costs. Hence, many governments promote the use of green energy by providing subsidies and teaching people its benefits in their life.

There are many ways green energy is produced, for example, solar energy, wind energy, the energy produced through bio-waste. Fuel cells are a major breakthrough in this regard. They have impacted the production green energy in many ways. They are also convenient to use. As their fuel (hydrogen, methane …) is produced by using electrical energy, they can use a wide range of green sources to produce energy.

What Are Fuel Cells?

A fuel cells is a device that converts chemical energy into electrical energy. The process combines hydrogen and oxygen to produce water& electricity as main products. Fuel cells are somewhat similar batteries. The main difference is that a fuel is supplied without a charge-discharge cycle. Like batteries, fuel cells are portable and can be used with a variety of fuels like ethanol, methanol, methane, and more.

There are different types of fuel cells. But the most popular ones are hydrogen fuel cells that provide a wide range with only some of advantages as follows:

  • The cells are more efficient than conventional methods used to produce energy.
  • They are quiet – unlike, for example combustion engines or turbines
  • Fuel cells eliminate pollution by using hydrogen instead of burning of fossil fuels.
  • Fuel cells have a longer lifespan than batteries because fresh fuel is supplied constantly
  • They use chemical fuels that can be recycled or produced using renewable energy which makes them environmentally friendly.
  • Hydrogen fuel cells are grid-independent and can be used anywhere.

How Do Fuel Cells Work?

A fuel cell produces power by transforming chemical energy into electrical energy in reduction-oxidation processes, much like batteries do. However, unlike batteries, they produce electricity from external supplies of fuel to the anode and oxidants to the cathode. Fuel cells are capable of producing energy as long as the fuel required to produce energy is supplied. Main components of fuel cells are electrolytes that allow for ion exchange. They aid the electro chemical reaction.

Hydrogen, ethanol, methanol, and methane are used as a source of energy. Methane, which is extracted from the subsurface, can be transformed into hydrogen rich stream. With an abundance of the hydrogen in nature, fuel cells seem to be the most viable technology that helps to produce green energy at large scale and at the most affordable cost.

Fuel cells are all set to become the most reliable source of green energy in the near future. They are fuel efficient, so businesses can make the best use of them. At Frontis Energy, we offer a unique selection that helps you build and improve your own fuel cells – be it for research and development or for production.

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How do the fuel cells work as an effective renewable power?

Fuel cells are the devices that convert chemical energy directly into electrical energy. The process combines hydrogen and oxygen produce water& electricity as main products. Fuel cells are similar to batteries in that they produce electricity but also different in that a fuel is supplied without a charge-discharge cycle. Like batteries, they are portable and developed by technological experts. The cells can be used with a variety of fuels like ethanol, methanol, methane, and more.

Here are the advantages of hydrogen fuel cells –

  1. The cells are efficient when compared to the conventional forms of producing energy.
  2. Hydrogen fuel cells operate silently.
  3. Fuel cells eliminate pollution by switching from burning of fossil fuels to hydrogen.
  4. Fuel cells last longer than batteries because they use chemical fuels to produce energy.
  5. Hydrogen fuel cells are grid-independent and can be used anywhere.

Components of Fuel Cells. A fuel cell converts chemical energy into electrical energy, much like a battery. But unlike batteries, they produce electricity from external supplies of fuels to the anode and oxidants to the cathode. Fuel cells can operate virtually continuously as long as the necessary fuel is supplied. Electrolytes are the major components of the fuel cells and keep that allow ion exchange. Fuel cells also have electrodes that are catalysts of the electrical chemical reaction.

Fuel for Fuel Cells. Fuel cells can operate using a variety of fuels like hydrogen, ethanol, methanol, and methane. Fossil fuels like methane are extracted from underground and converted into a hydrogen rich stream. There is also a huge abundant amount of hydrogen in water which can be used for the hydrogen power supply .For higher voltages, fuel cells can be stacked. Fuel cells can power anything from microchips to buses, boats, and buildings.

Fuel Cell Efficiency. The fuel cells are much more efficient than conventional power generation. This is because conventional power is generated be converting chemical energy into heat, mechanical energy and lastly into electrical energy. Fuel cells are converting energy directly into electrical energy and are much more efficient.

Fuels cells are a promising technology and already a source of electricity for buildings and vehicles. The devices operate best with pure hydrogen. In contrast, fossil fuel reserves are in limited and the energy future of the world needs to include several renewable alternatives to our declining resources. Hydrogen is the most abundant element present in the universe and serves as the fuel for nuclear fusion in the sun. Due to this abundance, hydrogen fuel cells are the best green energy source.

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Modern Day Fuel Cells – A Commercially Viable Green Alternative

Today’s companies are developing innovative techniques to use green energy such as fuel cells. There are different types of fuel cells under development, each with its own advantages, limitations, and potential applications. The classification is determined by the kind of electro chemical reactions taking place in the cell, the required kind of catalyst, the temperature range in which the cells operate, the required fuel, and other different factors.

Frontis Energy is an industry expert in fuel cells and electrolysis storage with more than 20 years of experience. We develop innovative environmental technology products and services. Our specialty is bio-fuels and wastewater with innovative solutions at competitive prices.

Fuel cells are clean, reliable, and portable

A fuel cell is a device that uses a source of fuel like hydrogen and an oxidant for creating electricity through electro chemical processes. It converts chemical energy into electrical energy like batteries found under the hoods of automobiles or in flashlights. The basic build-up is very simple. There are in principle two types of configurations which refer to the electrolyte and the two electrodes.

Many combinations of fuels and oxidants are possible in fuel cells. The fuel can be hydrogen, diesel, methanol, natural, etc., and the oxidants can be air, chlorine, or chlorine dioxide, and so forth. But most of today’s fuel cells are using hydrogen. The hydrogen used in fuel cells can be produced by a variety of fuels, including natural gas. A fuel cell splits hydrogen into electrons and protons. Fuel cells have several advantages over other common forms of power. They are cleaner, more efficient, and quiet.

There is no doubt that fuel cells are among the most efficient ways of green energy today. They are a decentralized and Eco-friendly alternative to conventional energy production. As the cost of centralized power rises, the cost of decentralized power continues to fall. Some power professionals believe the days of centralized power are numbered. Today, fuel cells are the best device to convert chemical energy into electrical energy.

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What is the need of Fuel Cell Technology?

Fuel cell technology is one of the best alternatives to fossil fuel combustion because it reduces air pollution affecting the health of millions. Fuel cells use hydrogen and oxygen from air to produce electricity with water being the final product. While the fuel, hydrogen, can be obtained from water, engineers use natural gas to produce most of today’s hydrogen. Nonetheless, a global hydrogen initiative of scientists and engineers has plans to look into renewable and environmental-friendly ways of producing hydrogen in the future.

Fuel cells have various advantages compared to conventional power sources like the internal combustion engines or batteries.

These are the benefits of fuel cells –

  1. Fuel cells have higher efficiency than diesel or gas engines.
  2. Fuel cells work silently and they are ideally suited for use within buildings like commercial constructions.
  3. Fuel cells such as hydrogen fuel cells eliminate pollution caused by burning fossil fuels.
  4. Fuel cell also eliminates greenhouse gases for example, when clean electrolysis of water is used.
  5. Fuel cells do not require conventional fuels like oil or gas (though they can use them) and thus reduce the economic dependence on oil-producing countries.
  6. Fuel cells generate electricity that can be distributed and be grid-dependent.
  7. Stationary fuel cells can be used to generate power at the point of use for small and medium decentralized power grids.
  8. High temperature fuel cells produce process heat that is suited to co-generation applications.
  9. Unlike in batteries, the operation time of fuel cells can be extended by increasing the amount of fuel.

Like a battery, a fuel cell has two electrodes which carry charges from one electrode to the other. The reaction in a single fuel cell produces only about 0.7 volts. However, if the cells are stacked and connected in in series, their voltage increases and they can be used in cars. Scientists and engineers are developing fuel cells that run on wastewater. These so-called microbial fuel cells use microbes to break down organic matter in the wastewater. This fuel cell technology is still requires cost optimization and performance improvements to become fully competitive.

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The Working of Fuel Cells

Fuel cells have a long history but currently experience a revival along with other forms of distributed generation to mitigate the greenhouse effect. They are a special type of galvanic cells which that can be fueled by solid, liquid, or gaseous fuel. The cells produce electricity through chemical reactions without hot combustion. They are there for particularly energy efficient. Most fuel cells convert hydrogen and oxygen into water in a process the leads to the generation of electricity. They are therefore electro chemical conversion devices is producing water, electricity, and small amounts of heat.

How do fuel cells work?

A fuel cell is using the chemical energy of the hydrogen or another fuel to efficiently produce electricity. To build a fuel cell, first make sure which fuel will be used. If hydrogen is the fuel, then electricity, water, and heat are the only products. The cells are unique in terms of the variety of potential applications. They can power everything from vehicles including spacecraft or an entire infrastructure.

Fuel cells are working like batteries and they do not need recharging, just refueling. They produce electricity as long as the fuel is supplied in a sufficient manner. The fuel cell is consisting of at least two electrodes namely a negative electrode (or cathode, where the positive charges travel to) and a positive electrode (or anode, where negative charges travel) − that is sandwiched around an electrolyte. A fuel like hydrogen is fed to the anode, and air or oxygen is fed to the cathode. A catalyst at the anode separates hydrogen molecules into protons & electrons, the latter generate electrical current.

The fuel cells are used in a wide range of applications, including transportation, material handling, and stationary, portable and backup power applications. The cells have numerous benefits over conventional combustion-based technologies currently used in power plants & vehicles. Fuel cells emit only water, so there are no carbon dioxide emissions during operation.

 Different elements of the fuel cell

The anode is the positive post of the fuel cell serving several purposes. Electrons are freed from the hydrogen molecules so that they can be used in an electrical circuit. Pores in the electrode disperse the hydrogen gas equally on the surface of the catalyst.

The cathode is the negative post and also porous. Oxygen gets dispersed on the surface of the catalyst and it can recombine with the hydrogen ions & oxygen to form water.

The electrolyte can be a proton exchange membrane or another porous or liquid material. Some membranes look like ordinary kitchen plastic wrap, put have micro pores to allow positively charged ions to pass through.

Catalysts are vital to fuel cells in that they facilitate the reactions of oxygen and hydrogen. They can be made of platinum nano-particles very thinly coated onto carbon paper, cloth, or other, arterial.

The proton exchange membrane is the heart of the cell and it allows protons to pass through it unimpeded blocking other compounds of that are also present in the electrolyte.

What are the advantages of fuel cells?

  • Fuel cells avoid the ‘thermal bottleneck’ and thus are more efficient than combustion engines. Chemical energy is directly converted into electrical energy which makes fuel cells more efficient than combustion engines.
  • Direct emissions from fuel cells are just water and a little heat. This is a huge improvement over internal combustion engines’ litany of greenhouse gases.
  • The cells do not contain moving parts and are therefore much more reliable than traditional engines.
  • The cells can be produced in an environment-friendly manner, as opposed to oil refining which is very damaging our environment.

Hydrogen fuel cells do not produce air pollutants or greenhouse gases and significantly improves the environment. The cells are the most efficient form of energy conversion apparatuses converting chemical into electrical energy.