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Wednesday, February 29, 2012
Hydrogen is the cleanest source of energy that can power your homes and fuel your cars. It can potentially substitute diesel and petrol or coal and clean up our environment. Hydrogen has been manufactured industrially for the past several decades and transported across thousand of kilometers by pipelines in Europe. The science and technology of Hydrogen is well known but its application to generate power and fuel a car is relatively new. The gasoline internal combustion engines that drive our gasoline cars can be modified to suit Hydrogen fuel. But the physical and chemical properties of Hydrogen gas created a necessity to alter existing gasoline engines for commercialization. But such conversion has been painfully slow for couple of reasons. There is a stiff resistance from gasoline cars to switch over to Hydrogen because they have a well established infrastructure to manufacture gasoline cars and to supply gasoline through well established distribution network. But Hydrogen cars lack both of them. Even if the cars can be modified for Hydrogen, there are no sales or distribution network for the fuel Hydrogen, similar to Gasoline. Even consumers need to be educated that Hydrogen is safe, environmentally friendly and we need not depend on import of oil and so on. It is a blessing in disguise that Hydrogen can be generated by individual homes, business and industries for their captive use from their tap water. Recently Hydrogen fuelled scooters have been introduced in the market. There are number of advertisements in the media too; that you can fit a Hydrogen generator at your car that will reduce your gasoline bills substantially and also reduce your emissions.But these Electrolyzers can generate only water gas and not a pure Hydrogen. Yet such simple devices can help reduce your petrol bills to an extend .If things are so simple why are we still struggling with high crude oil prices and increasing electricity bills? Let us examine this in detail. Water (H2O) can be split into Hydrogen (H2) and Oxygen (O2) by simply passing an electric current through water using a battery. The water disassociates as follows: 2H2O ------------- 2H2 + O2 Stochiometrically, it means 36 lits of water will generate 4 Kgs of Hydrogen and 32 kgs of Oygygen.The current PEM (Proton exchange membrane) Fuel cell car (Honda FCX clarity) can drive 100 miles with just 0.105 kgs of Hydrogen from 5000 psi Hydrogen tank. Similarly 4kgs of hydrogen can generate about 100 kws of electricity using PEM Fuel cell, based on a conservative estimate; but 4Kgs of gasoline can generate only 15 kW electricity. The gasoline engine offers only 100km mileage from 13 kgs (16lits) of gasoline. In other words, 0.105 kgs of Hydrogen at 5000 psi gives the same mileage as 16 lits of Gasoline. This is the amazing power of water, yet to be unleashed! The tap water is suitable to generate Hydrogen by adding a little amount of potash lye to improve the electrical conductivity. An Alkaline water electrolyzer can be attached to the water tank to generate required amount of Hydrogen based on the above calculation. The resulting Hydrogen has to be compressed to a required level. The power consumption to electrolyze water will be about 75-80 kwhrs per Kg of Hydrogen generated at 5000 psi.Therefore 4Kgs of Hydrogen will require a power of 300kwhrs costing about $30 for a total mileage of 3800 miles. You will require a small reverse osmosis unit to be attached to your water tap so that the water is de-ionized so that there is no precipitation in the Electrolyzer or reduction in the efficiency of electrolysis. Recently, Suzuki Bargeman introduced Hydrogen Fuel cell scooter which claims to offer a mileage of 200km from 12 lits Hydrogen (carbon composite material) tank at an elevated pressure of 10,000psi.The future of Hydrogen car is very promising and finally the world can hope to get rid of smoke and noise from our roads and cities.
Monday, February 27, 2012
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.
Wednesday, February 22, 2012
Our modern civilizatiztion has been shaped by oil or Hydrocarbons for several decades to such an extent that there is no immediate substitute for petrol, the world can count on. In fact the world has been complacent about the availability of Hydrocarbon, its applications and its future. Political leaders have been competing with each other to make sure that their supply of oil and gas is guaranteed as a matter of national security. Some countries even waged wars to secure oil fields. This situation is getting worse, as the supply of oil and gas are becoming uncertain and supplies dwindling. Each and every human being in the world is affected by oil and gas in one way or other, irrespective of the size, geography and rate of industrialization. The main reason for this situation is, the contribution of hydrocarbons made in the field of power generation and transportation. Currently more than 80% of power generation comes from fossil fuels such as oil, gas and coal. The entire transportation industry all over the world depends on oil and gas. The petrochemical industry’s contribution to our modern civilization is tremendous. It encompasses a whole range of industries whether it is fertilizers or plastics and resins or chemical industries or drugs and pharmaceuticals or cosmetic and toiletries and so on. These major industries determine the progress, civilization and industrialization of a nation. Countries who have vast resources of oil and gas are one of the richest countries in the world, even though these countries have no other resources. Countries with vast population and resources have to depend on oil and gas imports for their industries and transports. Countries with vast mineral resources cannot operate their mines without power or transportation. It is time we examine why oil and gas has become such a critical components in the progress of a nation and how this situation can be overcome. The two major technologies, which depend upon hydrocarbons, are power generation and transportation. Both these technologies use heat as a primary energy. In power generation, heat energy is converted into mechanical energy and then to electrical energy. In transport industry, the heat energy of the fuel is converted into mechanical energy. In petrochemical industry; oil and gas are converted into various chemical products by various chemical reactions and processes. If we closely examine the Hydrocarbon molecule, one thing is obvious. In a Hydrocarbon molecule, Hydrogen atoms are attached to carbon atoms. A simple example is, Natural gas or Methane gas, represented by chemical formula CH4. Four Hydrogen atoms are attached to a carbon atom, which actually imparts the heat energy (heat content) to the molecule. Without Hydrogen atoms, it is nothing but carbon. If we examine the heat value of Natural gas and Hydrogen, one will understand that Hydrogen has got a higher heating value. What is more interesting is there will be no greenhouse emission (carbon dioxide or carbon monoxide) by combusting Hydrogen. It is only water that is the byproduct of combustion of Hydrogen. If we can generate power or drive a car by combusting a Hydrocarbon, then why not combust Hydrogen to generate power or drive a car using the same combustion process? Even if one considers Hydrogen as too dangerous to handle, a mixture of a minor portion of biogas or natural gas with Hydrogen should solve the issue. It is certainly possible and only Hydrogen can replace oil and gas. We can use a combustion technology we knew for decades or use Fuel cell technology that we start using recently with Hydrogen. It is a clean technology and it does not emit smoke or make noise. Whichever way we looks at it, only hydrogen can replace Petrol. Sooner it does, better for the world.