‘Clean Energy and Water Technologies’ is now a social enterprise based in Melbourne, Australia. The purpose of this enterprise is to introduce a zero emission technology developed and patented by Ahilan Raman, the inventor of the technology. A 25 Mw demonstration plant will be installed to show case the above technology. This platform also used as a blog will publish articles relevant to Zero emission technologies for power and Zero liquid discharge technologies for water industries.
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Showing posts with label Fuel cell. Show all posts
Showing posts with label Fuel cell. Show all posts
Friday, July 19, 2019
Renewable Hydrogen, an emerging alternative to fossil fuel
Sunday, November 5, 2017
Carbon Recycling Technology
Wednesday, April 19, 2017
CAPZ desalination technology uses only Sun,Sea and WInd !
Friday, November 14, 2014
Why climate change is irreversible and Science is helpless?
Friday, March 21, 2014
It is time to switch over from Carbon to Hydrocarbon
Tuesday, May 15, 2012
Concentrated solar power - a game changer
Sunday, March 11, 2012
How to increase energy efficiency and reduce Carbon foot print?
There are many ways to increase the energy efficiency of an existing system which also helps invariably to reduce your carbon footprint. The inefficiencies breed pollution. Such inefficiencies can emanate from power generation methods or from power distribution methods. Energy cannot be stored but has to be utilized. That is one of the main reasons why the power companies look for large consumers and offer them the lowest tariff. Some industries like Caustic soda plants and Aluminum smelters, consume large power.
If you are using power from the grid then you can discuss with your service provider and check whether you can switch over to green power. The tariff may be slightly higher than a standard tariff but certainly helps you to reduce your carbon footprint. Some service providers indicate your carbon foot print by way a chart in their monthly energy bill. Most of the energy providers supply green power such as solar and wind as part of their energy mix to ensure that they don’t lose customers who may insist on green power.
You can check various power tariffs in your location such a peak tariff and off-peak tariffs and you will be surprised at the difference. The peak tariff is when everybody use power , normally 9am to 5pm.The usage of air-conditioners during peak hours in tropical countries is high They can use rooftop solar panels with batteries and inverters because many counties in Asia do not have feed-in tariff method by which you can export your surplus solar power to the grid. Moreover they do not have a choice in selecting a service provider because power generation and distribution are mostly runs by Governments or by very few service providers. The best method for such users is to store the solar energy in batteries and use them whenever they want. Even consumers who use grid power can store electricity during off-peak period using batteries and then use them during peak period using an inverter. This is an ideal solution for Asian countries where the power outage is frequent and unexpected.
The best method will be to use an Electrolyzer to generate Hydrogen using off-peak power and tape water and store them under pressure. You can generate your own electricity using small Fuel cell .This electricity can be a Direct current that can be readily connected to a host of Direct current operated appliances including your air-conditioners and refrigerators. If your electricity load is relatively high then you can integrate both solar panels and grid power in such a way that you can store enough electricity by way of Hydrogen or in a battery and use them during peak period. By this method you can be certain of an uninterrupted power supply and at the same time a reasonable power tariff. You can reduce your carbon foot print substantially by utilizing solar power with Hydrogen storage.
You can choose energy efficient appliances by looking at their star ratings.A star rating of 6 and above is considered very energy efficient. You can choose LED bulbs for lighting and I would suggest using Direct current for LED bulbs directly from Fuel cell or battery rather than from grid supply using an inverter. You can also check the type of refrigerants used in air conditioners and Refrigerators and their star ratings. If you have a roof top solar panel as part of electricity supply then I will recommend to use Direct current operated Air-conditioners and regfigerators.When you choose these appliances you can look for the type of motor, compressor and fans used, because these are the main parts that use electricity. An energy efficient motor and the type of compressor used are critical components in determining the capacity, airflow and noise levels. The energy ratings are based on these factors only.
You can save energy and reduce your carbon footprint in every step of the way if you are keen to do it. The most important factor in achieving energy efficiency is an understanding of your contribution to the environment and the prudence with which you can accomplish these goals.
Wednesday, March 7, 2012
All roads lead to Hydrogen
We have discussed about the formation of fossil fuel as part of carbon cycle. It takes several million years before the carbon from the plants and animals turn into fossil fuels due to chemical reactions under higher pressure and temperature. The fossil fuels include solid coal, liquid oil and gaseous Hydrocarbons such as crude oil and natural gas. The natural gas forms the top layer due to its lightness. Natural gas is also the result of anaerobic reaction by microorganism in the absence of air converting organic matter under the earth into a gas. The gas during exploration comes with great pressure to be transported across several kilometers. We are actually duplicating this process to generate Biogas from our food and agriculture wastes and other organic matters. The end product is a mixture of methane and carbon dioxide. During oil and gas exploration we get methane and carbon dioxide and other gases such as Hydrogen sulfide depending upon the location of the oil field. That is why Sulfur and other products such as Mercaptnans are present in crude oil and natural gas. When these fossil fuels are burnt the gaseous combustion products contain sulfur dioxide and oxide of nitrogen along with oxides of carbon. Air is normally used for combustion which is a mixture of Nitrogen and oxygen in the ration of 71:21,therefore, the combustion products invariably consist of oxides of nitrogen.
We are so addicted to oil and we are even trying to convert natural gas into oil, similar to gasoline using GTL (gas to oil) process. However all these combustion processes can be reacted with steam to form synthesis gas, a precursor for liquid Hydrocarbon. It is quite obvious that water in the form of steam is a key component in future energy mixes because that is how one can introduce a Hydrogen molecule in the reaction process. Hydrogen in the form of water is the key. Even if we can successfully steam reform natural gas to get Hydrogen we still have problems deal thing with traces of sulfur and mercaptans, potential poison for catalyst in PEM (Proton exchange membrane) Fuelcells.The idea is to generate Hydrogen using a carbonaceous source such as fossil fuel for simple reasons. It is abundantly available but it emits greenhouse gases; but when you introduce Hydrogen into the mix then there is a good possibility of reducing greenhouse emission, even though we still use fossil fuels. Secondly, we are cautious to handle pure Hydrogen due to its explosive nature and the best available option is to mix Hydrogen with combustion products of fossil fuels. The result is the formation of Syngas.
Syngas is an important intermediary that will lead us to the Hydrogen economy of the futue.The syngas can be generated by various methods as long as we have an organic source and water (steam) source. In fact all food and agriculture waste can be converted into syngas either using a biological process or by gasification process. Both will lead to formation of Methane or syngas.
Syngas is a mixture of hydrogen with carbon dioxide formed in the following sequences, starting with carbon ,air and steam.
2C + O2-------- 2 CO,
2CO + 2H2O---------2H2 +2 CO2
The carbon source can be any organic source such as coal, coke, wood etc.As you can see in the reaction, the quantity of carbon source is equally important to generate Hydrogen. One can say that Syngas is a match maker between fossil economy of the past and Hydrogen economy of the future. It is a very important chemical reaction that will change the future energy scene in the world.
That is why many counties like US and Australia and in Europe who have considerable coal deposits are now trying to generate Hydrogen from coal. Once coal is converted into a gas such as syngas then they are one step closer to separate Hydrogen from syngas.Number of companies and Research organizations around the world are trying to develop an efficient and economical method of generating Hydrogen from coal. They have to find suitable conditions to generate higher yield of Hydrogen from syngas and then find an efficient system to separate Hydrogen from carbon dioxide. As I have mentioned earlier, the purity of Hydrogen is important especially when we use coal as the basic material because it contains number of impurities to be removed before converting into a syngas.
As we can see, all energy roads are now leading to Hydrogen as the ultimate clean fuel of the future. When the demand for Hydrogen increase, the demand for water too will increase because it is the direct source of Hydrogen. Energy and water are two side of the same coin as I have mentioned earlier in the past.
Saturday, March 3, 2012
Regenerative Fuelcell- Water and Fire
In a regenerative fuel cell the results of redox reaction between Hydrogen and Oxygen, are power and water; the above reaction can be reversed in the same electrochemical process to regenerate hydrogen and oxygen. Such a system is called ‘regenerative fuel cell’. It is a perfect example of a closed circuit system. In ancient Hindu mythology there were citations that claim water came from fire and fire came from water. Two gaseous elements Hydrogen and oxygen reacts violently rather explosively resulting in cool water. Perhaps Hindu mythology terms this reaction as fire which results in water. Similarly by passing a direct current into water, it splits water into oxygen and renegenerates Hydrogen, which is a symbolic representation of Fire. Many would have watched a number of ‘you tube video footings’ on water gas. The water gas or Brown’s gas is a mixture of Hydrogen and oxygen along with undissociated water molecules liberated during the process of electrolysis. It can be lit into a flame similar to Oxy-acetylene flame and can be used even to cut metal plates. That is the power of brown’s gas, which I call Oxy-Hydrogen gas. This torch is commercially marketed for metal cuttings applications. But production of pure Hydrogen completely free from Oxygen is a matter of great commercial importance.
Hydrogen is one of the lightest gases and it has a strong bondage with noble metals like Platinum and Palladium. Platinum as a catalyst with carbon as a carrier has a wider industrial applications such as Hydrogenations in fine chemicals and pharmaceuticals. The author has experience in such applications in bulk drug manufacturing such as Ephedrine and Paracetamol. In a PEM (proton exchange membrane fuel cell) MEA (membrane electrode assembly) is the heart. The Platinum catalyst coated on the surface of the ‘Nafion’ membrane reacts with gaseous Hydrogen gas. It strips the electron from hydrogen atom while the polymer membrane allows only proton to pass through. The expelled electron flows around the circuit. Flow of electron is nothing but current or electricity. The proton crosses the membrane and reacts with incoming Oxygen through cathode forming water. It is an exothermic reaction and generates heat similar to any combustion reaction, that has to be dissipated.In larger installation we can use this waste heat for a typical CHP (combined heat and power applications) such as power and steam or chilled water or for space cooling. Fuel cell (based on Hydrogen fuel) operates quietly with absolutely no emission except water, and of course, there is no smoke. It is an ideal power source for 24x7 applications such as hospitals, call centers, departmental stores and continues process industries.
In the reverse process of a Fuel cell, the electrochemical devise becomes an Electrolyzer splitting water into Hydrogen and oxygen. The electrolyzer works the same way as Fuel cell but in reverse;the feed is de-ionized water and the products are Hydrogen and Oxygen. In bipolar alkaline electrolyzer, a catalyst such as potash lye is added whereas in solid polymer electrolyzers platinum acts as a catalyst similar to a Fuelcell. The generated Hydrogen comes under pressure obviating the use of an additional compressor. The Hydrogen is stored in cylinders for further usage.
As I mentioned in my previous articles the power required to split water into Hydrogen and Oxygen is more than the power generated from the resulting Hydrogen by a Fuelcell.That means an input of excess energy is necessary for a regenerative fuel cell to operate successfully .Where this energy will come from depends on the cost benefit analysis to be made. Surplus Hydro power is ideal for such regenerative fuel cell applications. But we can also use various other renewable energy sources such as wind, solar, geothermal, OTEC depending upon the location and applications. The biggest advantage with regenerative fuel cell is there is no other input except the excess power to be supplied. When renewable energy is deployed on large commercial scales then regenerative fuel cell will become a clean solution of the future. I have no doubt in my mind that this will become a commercial reality. Of course the top policy makers should understand the potential and make a right decision and encourage more business and industries to deploy such systems. The energy costing model cannot be based on fossil fuel model because fossil fuel is not renewable. This is the crux of the problem.
In our future articles we will present case studies of various clean energy systems that are already in commercial operation. I also welcome articles from clean energy professionals with real life project experience and problems they face. I welcome comments and feedback from business, industries and individuals.
Monday, February 27, 2012
Water- Fuel of the future
Water constitutes 71% of the planet earth and it is the most potential energy source of the future. Water is a product of combustion between Hydrogen and Oxygen, two most abundantly available elements and vital for life on earth. The bondage between Hydrogen and Oxygen is so strong that it requires certain amount of energy to separate them. Separation of Hydrogen and Oxygen using the process of Electrolysis is a well known technology. Separation of water by high temperature using Thermolysis has also been studied. In both the processes the separation of Hydrogen and Oxygen after decomposition is a key step because of the strong affinity between the two elements. Hydrogen has to be separated in a pure form without any trace of Oxygen. Currently most of Hydrogen is generated commercially by steam reforming natural gas because of its easy availability as piped gas in many developed countries. Moreover steam reforming is a well established commercial technology that has been used for decades in chemical process industries. The hydrogen resulting from steam reforming is acceptable for combusting in Hydrogen internal combustion engines but not pure enough for a Fuel cell car. Any trace of impurity from natural gas such as Sulfur or mercaptans can potentially poison the catalyst used in fuel cell which is very expensive. Hydrogen with purity less than 99.99% is not recommended for Fuel cell applications.
Currently there are few issues to be addressed before Hydrogen becoming a commercial fuel. The energy required to separate Hydrogen from water by commercial electrolysis is about 6Kws (kilowatts) to generate 1 m3 (cubic meter) of Hydrogen. Two key factors for electrolysis are purity of water and DC power source. Water of certain purity is a critical component for Hydrogen generation. Deionized water with electrical conductivity less than 0.10 micro Siemens/cm is required. Normal drinking water conductivity is less than 100micro Siemens/cm. The potable water can be deionized with reverse osmosis system to get necessary quality. In fact both high purity water and direct current are not commercially available. A renewable energy sources such as solar or wind that generates direct current can be used for electrolysis. This will eliminate batteries and rectifiers that we normally use in renewable energy systems. The generated Hydrogen can be stored in cylinders under high pressure. The stored hydrogen is the stored energy that can be used as and when required. We can use the stored Hydrogen to generate electricity to meet our power requirement whether it is a home or business or industry. The major advantage with this system is that we can generate power whenever we need and we don’t have to depend on the grid power. We can also export surplus power to the grid. In fact all DC appliances can be connected with DC power from Fuel cell and operated to improve the efficiency. Such a system is ideal for remote locations without any grid supply such as remote villages or islands.
The same stored Hydrogen can also be used as fuel for a car whether it is a combustion engine or a Fuel cell car. Hydrogen can be compressed and stored under high pressure. Alternatively, Hydrogen can be stored using metal hydrides in smaller volumes. Honda introduced the first fuel cell car in the market in 1999. Since then they have made considerable improvements. Honda FCX Clarity, sedan offers a mileage of 270 miles for a single cylinder of Hydrogen at 5000 psi pressure. They are introducing a latest model with Hydrogen pressure at 10,000 psi which will considerably improve the mileage further. Unlike Hybrid cars, Fuel cell cars run silently and experts who have test-driven the car are very much impressed with the performance. Similarly Ford introduced Hydrogen combustion engine 6.8 liters V-10 engine to power E-450 Hydrogen shuttle bus. Ford modified their Gasoline engine to suit Hydrogen fuel.
Substituting Gasoline with Hydrogen is no longer a theory but a commercial reality. More and more research is being undertaken to improve the performance. Currently the cost of Hydrogen cars and Hydrogen fuel is expensive, due to lack of infrastructures to manufacture such cars or to distribute Hydrogen. However these cars will soon replace gasoline cars. Similarly individual homes and business can generate their own electricity for their daily use using stored Hydrogen. Water will become the fuel of the future and Hydrogen will clean up the air that has been heavily polluted by fossil fuels for decades.
Monday, February 20, 2012
Fuel Cell- a new concept in power generation
Power generation using fossil fuels is a well established technology dating back to 1839, when Michael Faraday invented the principle of Electro-magnetism. There was not much of a change in this technology all these years. But recently greenhouse emission and global warming has become an issue; and the world started looking for an alternative source of energy and method of power generation. However it is not an easy task to develop completely a different technology as well as a fuel in a short span of time, while an unabated man-made greenhouse gas emission continues. Scientists are now warning catastrophic consequences if the greenhouse gas emission is not curtailed with great urgency.Untill now the world was able to avert some of the potentially catastrophic events happening, like ozone layer depletion, pandemic bird flu etc.But global warming is a new thereat that demands an entirely a new solution and a swift action. But majority of countries in the world are not is a position to curtail greenhouse emission gas, simply because there is no alternative fuel known, except fossil fuels. Renewable energy is relatively a new concept. Though solar and wind energy sources were known long time back, they were not persuaded seriously because they could not compete with conventional fossil fuels. But the time has come for new emerging technologies that can not only compete with fossil fuels but also eliminate greenhouse emissions. The world has invested massively on fossil fuel infrastructures and still investing heavily on oil and gas explorations. Obviously there is no end in sight as far as fossil fuels are concerned and the world is carrying on business as usual.
Meanwhile a new technology based on fuel cell is emerging as an alternative for power generation. Fuel cell is a known concept and it has been successfully deployed in ‘Apollo space programme in space shuttle. This old version of alkaline fuel cells was replaced with PEM (proton exchange membrane) fuel cell or (PEMF) Polymer electrode membrane fuel cell. This new version was used in Gemini’s space programme in sixties. Fuel cell is an electro chemical devise that uses Hydrogen gas as a fuel and it operates at ambient temperature. It is like a battery cell. The difference between fuel cell and batteries is the Fuel cell will keep generating power as long as fuel is supplied unlike a battery, where energy is stored in the form of chemical energy and converted into electrical energy when used by connecting through a conductor. Battery needs recharging but Fuel cell requires refueling. The fuel used in Fuel cell is invariably Hydrogen. Conventional power generation involves combustion of fossil fuel (heat energy) which drives a turbine (mechanical energy) to run an alternator to generate power (electrical energy).In fuel cell; Hydrogen gas reacts with oxygen from the atmosphere (electrochemically) to generate power. It produces water as by-product. The efficiency of Fuel cell is about 50-60% compared to 35-40% by steam or gas turbine. In regenerative fuel cell, water can be split into Hydrogen and oxygen using same proton exchange membrane elecrolyzer.The resulting Hydrogen can be used as a Fuel to the PEM Fuel cell to generate power, thus recovering water. It is a closed circuit system. There are no mechanical moving parts, no combustion, no smoke or no noise. It is a quiet and clean operation. It is a very promising technology that can revolutionize the way we produce fuel and generate power. The Hydrogen and fuel cell combination is used in cars. Honda FCX (fuel cell model) cars work on the same principle and they are already on roads!
One problem with Hydrogen generation is it requires more power to split water, into Hydrogen and oxygen, than the power generated by resulting hydrogen, using Fuel cell. However, this technology will change the future of power generation by eliminating greenhouse emission completely. But how long it will take to become a commercial reality is something to be seen! If political leaders and Governments around the world recognize the potential of this technology and take bold decisions coupled with swift actions, probably our future generation can breathe a clean air.
Saturday, February 11, 2012
Can Electric cars eliminate greenhouse gas emission?
There is a myth, that electric cars will eliminate greenhouse emissions, and reduce the global warming. Electric cars will not reduce the greenhouse emission, because, you still need electricity, to charge your batteries. Companies promoting electric cars, are now planning to set up their own battery charging stations, because, you have to charge the batteries of these electric cars, every now and then. Otherwise, they will not be able to market their electric cars. Moreover, there is currently no battery in the market that can last more than 28 hours between the charges, though many companies are trying to develop superior batteries. One company claims a battery capacity of 300whr/kg, for their Lithium polymer battery, much superior than other batteries, which can run 600kms, with 6 minutes charging. Though, new batteries such as semi solid Lithium ion batteries, based on the principle of ‘flow batteries’, are promising, it is still, a long way to commercialization. President Obama, has set a set a target of 1 million electric cars in US roads, by 2012.It is estimated that US has to produce about 40 billion dollars worth of domestically produced batteries. A lithium ion battery, which weighs less, and stores more energy, is the promising technology. But, the Lithium resources are limited. Battery is the heart of an electric car. It is true, that electric cars do not emit smoke, or make noise like petrol cars. But, these two factors alone, are not sufficient, to substitute traditional, fossil fuel powered international combustion engines.
It is equally true, that electric cars can reduce green house emission, to an extent, where fossil fuel consumed cars, are replaced with electric cars. To that extend, the fossil fuel consumption by these cars are reduced. But, the power to charge the batteries, will still, have to come from the common grid. Unless, the power generation technology, using fossil fuels is changed, there will be no dramatic greenhouse gas emission reduction, by introducing electric cars. Alternatively, if cars are built on Hydrogen based fuel, either using a conventional internal combustion engine, or by using Fuel cell, then, a substantial amount of greenhouse emission, can be eliminated. However, the Hydrogen generation, should be based on renewable energy source only. Whichever way, you look at it, renewable energy is the key. Those Governments and companies, who do not invest in renewable energy technologies and systems, now, will have to pay a heavy price, in the future. But, even those companies, investing on renewable energy technologies, should look beyond current technologies and systems. The best starting point, for these industries will be, to substitute ‘storage batteries’ with ‘stored Hydrogen’.
It is much simpler, to install PV solar panels or wind turbines, and to generate, Hydrogen, onsite, from water. You can store Hydrogen in fuelling stations, and fuel the cars. Honda was the first entrant into this market, who was focusing fuel cell technology, using compressed hydrogen gas. Alternatively, such Hydrogen can be generated from ‘Biogas’ generated from biological wastes and waste treatment plants. All necessary technologies are currently available to make it happen. Governments can try to promote small townships with Hydrogen fuel stations, and show case such models, to the rest of the country or other nations to follow. This will help nations, to reduce their greenhouse emission, and at the same time, they can become self sufficient in their energy requirements. They no longer, have to depend on polluting oil and gas, from few Middle Eastern countries. Countries, like India with impressive economic growth, heavily depend on oil imports, and any slight fluctuation in oil prices, can easily upset such growth. It is time Governments around the world; take a serious look at Hydrogen, as their alternative energy source. It is just not good enough, to promote renewable energy technologies, but they have to develop generation, storage and distribution technologies also, for Hydrogen. What is needed at this hour, is ‘will, determination and leadership’ on the part of the Governments like US, China and India, that can set an example, for the rest of the world, by investing in Hydrogen economy.
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