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Saturday, May 5, 2012
Tuesday, March 27, 2012
There is so much discussion about Hydrogen as a source of clean energy because, it is the choice of Nature. Nature has provided us with fossil fuels which are Hydrocarbons, chemically represented by CxHy, Carbon and Hydrogen atoms. In the absence of Hydrogen in a Hydrocarbon, it is nothing but Carbon, which is an inert material. The Hydrocarbon gets its heating value only from the presence Hydrogen atom. The natural gas, now considered as the cleanest form of Hydrocarbon is represented by the chemical formula CH4, has 25% Hydrogen by weight basis. It represents the maximum Carbon to Hydrogen ratio at 1:4.This is the highest in any organic chemicals. In aromatic organic compounds such as Benzene, represented by C6H6, the Hydrogen content is only 7.69%.Even in Sugar which is an organic compound from Nature, represented chemically as C12H22O11 has only 8.27% Hydrogen. But Bioethanol, derived from sugar represented by C2H5OH has almost 13% Hydrogen. Ethyl Alcohol known as ‘Bioethanol’ derived from sugar is blended with Gasoline (Hydrocarbon) for using as a fuel in cars in countries like Brazil. Brazil is the only country that does not depend on imported Gasoline for their cars. The same Bioethanol can also be derived from Corn starch. But the starch should first be converted into sugar before alcohol is derived; it is more expensive to produce Bioethanol from corn starch than from cane sugar molasses. The climatic conditions of Brazil are more favorable for growing Cane sugar than corn. Brazil is in a more advantageous position than North America, when it comes to Bioethanol. US is one of the largest consumer of Gasoline.US has imported 11.5 million barrels/day of oil in 2010.It has used 138.5 billion gallons of Gasoline (3.30billion barrels) in 2010) according to EIA. (US Energy Information Administration) It is estimated that Brazil’s sugar based Alcohol is 30% cheaper than US’s corn based Alcohol. Brazil has successfully substituted Gasoline with locally produced alcohol .They also introduced ‘flexible fuel vehicles’ that can use various blends of Alcohol-Gasoline. Most of the Gasoline used in US has 10% Ethanol blend called E10 and E15, representing the percentage of Alcohol content in Gasoline. Brazil is the largest producers of Bioethanol in the world. Both Brazil and US account for 87.8% of Bioethanol production in the world in 2010 and 87.1% in 2011.Brazil is using Bioethanol blends of various proportions such as E20/E25/E100 (anhydrous alcohol) (Ref: Wikipedia). Almost all cars in Brazil use Bioethanol blended Gasoline and even 100% anhydrous Bioethanol is used for cars. Brazil has set an example as a ‘sustainable economy introducing alternative fuel’ to the rest of the world. The 'bagasse' from cane sugar is also used as a fuel as well in the production of ‘Biogas’, which helps Brazil to achieve sustainability on renewable energy and greenhouse gas mitigation. The above example is a clear demonstration of sustainability because natural organic material such as sugar is the basic building block by which we can build our clean energy source of the future. The same Bioethnanol can easily be reformed for the production of Hydrogen gas to generate power and run Fuel cell cars. Many companies are trying to use chemicals such as metal Hydrides as a source of Hydrogen. For example, one company successfully demonstrated using Sodium Borohydride for Hydrogen generation. Many companies are trying to find alternative sources of Hydrogen generation from water, including Photo-electrolysis using direct solar light and special photo catalyst materials. We know Nature produces sugar by using sun’s light, water and carbon dioxide from air by photosynthetic process. Can man duplicate this natural process and generate Hydrogen at the fraction of the cost by simply using water and sun’s light? The race is already on and only time can tell whether our pursuit for cheap and clean Hydrogen can become a commercial reality or just stay as an elusive dream.
Friday, March 9, 2012
Renewable Hydrogen is the key that can provide us energy independence in the twenty first century. Fossil fuel usage will still continue for some more time because the world has already invested massively on fossil fuel infrastructures. The stacks are too high for them to switch over to renewable over night. It is the Mother Nature who provided us coal, oil and gas all these years using her manufacturing process under the earth over millions of years. But we human beings exceeded her tolerance limit by emitting greenhouse emission by our rapid growth in population and industrialisation.We failed to discover an alternate fuel in time and continued with an age old technology with all its inefficiencies. Inefficiencies breed pollution. We were keen to use the heat of combustion by burning a fossil fuel to generate electricity or drive our cars, but paid no attention to the gases released during such combustion. We learnt Thermodynamics and the relationship between heat and work, but failed to understand the consequences of gases of combustion and its impact on our environment. There are two issues involved in burning a fossil fuel to generate electricity. The heat of combustion is an exothermic reaction and we get certain amount of heat. Then we convert this heat energy into electrical energy and the overall efficiency of such conversion is about thirty-five percent. Only thirty-five percent of the heat input energy becomes electrical energy and the remaining sixty-five percent heat along with gases of combustion are released into atmosphere. Of course part of this heat is recovered in a commercial plant, but the bulk of heat is released into the atmosphere as greenhouse gases. We failed to understand the potential of Hydrogen even though we used Hydrocarbon for several decades. We even discovered Urea, the fertilizer that caused ‘green revolution’ in agriculture, using the same Hydrogen present in the Hydrocarbon feedstock. It is time for us to make best utilization of a fossil fuel to its maximum potential when we burn each kilogram of fuel. We should burn coal not just with air but also with steam so that we can generate Hydrogen rich gas that can run a gas turbine in a combined cycle or run our cars on roads. Such a conversion will lead to a substantial increase in energy efficiency as well as in greenhouse gas emission reduction. Governments in industrialized countries should make it a mandatory to convert all their power plants to syngas generation as described above. They should also discourage new plants using fossil fuels with punitive power tariffs and encourage renewable energy projects with higher tariffs. Governments can also impose similar tariffs for transportation depending upon the fuel used such as fossil fuel or Hydrogen. Governments should encourage renewable energy projects such as solar and wind to generate Hydrogen from water as centralized power plants and distribute DC (direct current) by rural electrification. If the country side is electrified using this system then, agriculture, business and industries can thrive in rural areas. Direct current (DC) distribution net work can be installed in rural areas and encourage people to use energy efficient appliances such as Direct current air-conditioners with energy star ratings and tariffs. Governments can bring about these changes by adopting a ‘carrot and stick ‘policy to encourage renewable and discourage fossil fuels. Solar energy is the key from which all other forms of energy emanate such as wind, geothermal and ocean thermal energy conversion system. It is of paramount importance to increase the efficiency of renewable systems and improve energy efficiencies of appliances we use. It is simpler to use LED bulbs using a Direct current generated by Renewable Hydrogen. It is once again the Mother Nature, who can come to the rescue of human beings through solar, wind and water to generate clean energy for the twenty first century. Energy generation and distribution is no longer a business or revenue issue but a moral and ethical issue for Governments. It is only people who can bring about such sweeping changes by electing the right Government who can care for the environment. The future generation will judge us only based on what kind of an environment we leave them behind.
Wednesday, March 7, 2012
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.
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.
Monday, February 13, 2012
Why I say “water and clean energy, are two sides of the same coin?” At the outset, it may sound odd, but in reality, these two are closely interconnected. Let us examine, step by step, how they are connected, to each other, and what are the implications, in terms of cost, and environmental issues. Take for example, power generation industries. The two basic materials, any power plant require, are, fuel and water. It does not matter, what kind of fuel is used, whether it is a coal based power plant or liquid fuel based plant like Naphtha, or gas based plants, like piped natural gas or LNG Of course, this statement is applicable only, for existing, conventional power generation technologies, and not for PV solar or wind energy, technologies. Let us consider, only power generation, involving conversion of thermal energy, into electrical energy. Today, more than 80% of power generation in the world, is based on thermal power, including nuclear plants. What is the usage of water in power plants? All thermal power plants use steam, as the prime motive force, to drive the turbines, (gas turbine is an exception, but, even in gas based plants, the secondary motive force, is steam, using waste heat recovery boilers, in combined cycle operations). The quality of water for conversion into steam is of high quality, purer, than our drinking water. The second usage of water is for cooling purpose. The water consumption by power plants, using once through cooling system is 1 lit/kwhr, and by closed circuit cooling tower, it is 1.7lit/kwhr .Only about 40% power plants in Europe, for example, use closed circuit cooling towers, and the rest use only ‘once through’ cooling systems. The total power generated in 2010, by two largest users, namely US and China, were 3792Twhrs and 3715 Twhrs respectively. The total world power production, in 2008 was 20,262 Twhrs, using following methods. Fossil fuel: Coal 41 %, Oil 5.50%, Gas 21%, Nuclear 13% and Hydro 16%. Renewable: PV solar 0.06%, PV thermal 0.004%, Wind 1.1%, Tide 0.003 %, Geothermal 0.3%, Biomass &others 1.30%. (1Twhrs is = 1,000,000,000 kwhrs) The above statistics, gives us an idea, on how much water, is being used, by power generating plants, in the world. Availability of fresh water, on planet earth, is only 2.5% (96. 5% oceans, 1.70% ground water, 1.7% glaciers and ice caps, and 0.001% in the air, as vapor and clouds).The world’s precious water source, is used for power generation, while millions of people, do not have water, to drink. The cost of bottled drinking water is US$ 0.20 /lit, in countries like, India. This situation is simply unsustainable. The prime cause, for this situation, is lack of technology, to produce clean power, without using water. The power technology, we use today, is based on the principle of electromagnetism, invented, by Michael Faraday, in the year 1839. That is why, renewable energy, is becoming critically important, at this juncture, when the world is, at the cross road. In order to overcome, the shortage of fresh water, many countries are now opting, for seawater desalination. Desalination, again, is an energy intensive process. For example 3-4 kwhrs of power is used, to desalinate 1 m3 of water. This power has to come, from fossil fuel fired, thermal power plants, which are often co-located, with desalination plants, so that, all the discharge, from both the plants, can be easily pumped into the sea. Since, the world is running out of fresh water, we have to look for alternative source of water. In countries like India, the ground water is being exploited, for agricultural purpose, and the ground water is getting depleted. Depleting water resources is a threat to agriculture production. It is a vicious circle. That is why, distributed energy systems, using Hydrogen as an alternative fuel, is an important step, towards sustainability. One can generate Hydrogen from water, using renewable energy source, like solar or wind, and store them, for future usage. The stored Hydrogen can be used to generate power, as and when required, at any remote location (even where there is no grid power).The water is regenerated, during this process of power generation using Fuelcell, which can be recycled. There is no large consumption of water, and there is no greenhouse emission. It is a clean and sustainable solution. The same stored Hydrogen can also be used as a fuel for your car! Therefore; one can say “water and clean energy, are two sides of the same coin”. (The above statistics are based on Wikipedia data).