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Friday, August 10, 2012

Irreversibility leads to unsustainability


People in the chemical field will understand the concept of ‘irreversibility’. Certain chemical reactions can go only in one direction and but not in the reverse direction. But some reactions can go on either direction and we can manipulate such reactions to our advantages. This concept has been successfully used in designing many chemical reactions in the past and many innovative industrial and consumer products emerged out of it. But such irreversible reactions also have irreversible consequences because it can irreversibly damage the environment we live in. There is no way such damage can be reversed. That is why a new branch of science called ‘Green Chemistry’ is now emerging to address some of the damages caused by irreversible chemical reactions. It also helps to substitute many synthetic products with natural products. In the past many food colors were made out of coal tar known as coal tar dyes. These dyes are used even now in many commercial products. Most of such applications were merely based on commercial attractiveness rather than health issues. Many such products have deleterious health effects and few of them are carcinogenic. We learnt from past mistakes and moved on to new products with less health hazards. But the commercial world has grown into a power lobby who can even determine the fate of a country by influencing political leaders. Today our commercial and financial world has grown so powerful that they can even decides who can be the next president of a country rather than people and policies. They can even manipulate people’s opinion with powerful advertisements and propaganda tactics by flexing their financial muscles. Combustion of fossil fuel is one such example of ‘irreversibility’ because once we combust coal, oil or gas, it will be decomposed into oxides of Carbon, oxide of Nitrogen and also oxides of Sulfur and Phosphorous depending upon the source of fossil fuel and purification methods used. These greenhouse gases once emitted into the atmosphere we cannot recover them back. Coal once combusted it is no longer a coal. This critical fact is going to determine our future world for generations to come. Can we bring back billions of tons of Carbon we already emitted into the atmosphere from the time of our industrial revolution? Politicians will pretend not to answer these question and financial and industries lobby will evade these question by highlighting the ‘advancement made by industrial revolutions’. People need electricity and they have neither time nor resources to find an alternative on their own. It is open and free for all. People can be skeptical about these issues because it is ‘inconvenient for them’ to change But can we sustain such a situation? Irreversibility does not confine only to chemical reactions but also applies for the environment and sustainability because all are intricately interconnected.Minig industries have scared the earth, power plants polluted the air with greenhouse emission and chemical industries polluted water and these damages are irreversible. When minerals become metals, buried coal becomes power and water becomes toxic effluent then we leave behind an earth that will be uninhabitable for our future generations and all the living species in the world. Is it sustainable and can we call it progress and prosperity? Once we lose
pristine Nature by our irreversible actions then that is a perfect recipe for a disaster and no science or technology can save human species from extinction. One need not be scientist to understand these simple facts of life. Each traditional land owners such as Aborigines of Australia or Indians of America and shamans of Indonesia have traditionally known and passed on their knowledge for generations. They too are slowly becoming extinct species in our scientific world because of our irreversible actions. Renewability is the key to sustainability because renewability does not cause irreversible damage to Nature.

Tuesday, August 7, 2012

Base load power generation with Solar thermal


All existing power generation technologies including nuclear power plants uses heat generation as a starting point. The heat is used to generate steam which acts as a motive force to run an alternator to produces electricity. We combust fossil fuels such as coal oil and gas to generate above heat which also emits greenhouse gases such as oxides of Carbon and Nitrogen. As I have disused in my previous article, we did not develop a technology to generate heat without combusting a fossil fuel earlier. This was due to cheap and easy availability of fossil fuel. The potential danger of emitting greenhouse gases into the atmosphere was not realized until recently when scientists pointed out the consequences of carbon build up in the atmosphere. The growth of population and industries around the world pushed the demand for fossil fuels over a period of time which enhanced the Carbon build up in the atmosphere. But now Concentrated Solar Power (CSP) systems have been developed to capture the heat of the sun more efficiently and the potential temperature of solar thermal can reach up to 550C. This dramatic improvement is the efficiency of solar thermal has opened up new avenues of power generation as well as other applications. “CSP is being widely commercialized and the CSP market has seen about 740 MW of generating capacity added between 2007 and the end of 2010. More than half of this (about 478 MW) was installed during 2010, bringing the global total to 1095 MW. Spain added 400 MW in 2010, taking the global lead with a total of 632 MW, while the US ended the year with 509 MW after adding 78 MW, including two fossil–CSP hybrid plants”. (Ref: Wikipedia) “CSP growth is expected to continue at a fast pace. As of April 2011, another 946 MW of capacity was under construction in Spain with total new capacity of 1,789 MW expected to be in operation by the end of 2013. A further 1.5 GW of parabolic-trough and power-tower plants were under construction in the US, and contracts signed for at least another 6.2 GW. Interest is also notable in North Africa and the Middle East, as well as India and China. The global market has been dominated by parabolic-trough plants, which account for 90 percent of CSP plants. As of 9 September 2009, the cost of building a CSP station was typically about US$2.50 to $4 per watt while the fuel (the sun's radiation) is free. Thus a 250 MW CSP station would have cost $600–1000 million to build. That works out to $0.12 to $0.18/kwt. New CSP stations may be economically competitive with fossil fuels. Nathaniel Bullard,” a solar analyst at Bloomberg “New Energy Finance, has calculated that the cost of electricity at the Ivanpah Solar Power Facility, a project under construction in Southern California, will be lower than that from photovoltaic power and about the same as that from natural gas However, in November 2011, Google announced that they would not invest further in CSP projects due to the rapid price decline of photovoltaics. Google spent $168 million on Bright Source IRENA has published on June 2012 a series of studies titled: "Renewable Energy Cost Analysis". The CSP study shows the cost of both building and operation of CSP plants. Costs are expected to decrease, but there are insufficient installations to clearly establish the learning curve. As of March 2012, there was 1.9 GW of CSP installed, with 1.8 GW of that being parabolic trough” Ref: Wikiedia. One Canadian company has demonstrated to generate Hydrogen from water using a catalytic thermolysis using sun’s high temepertaure.The same company has also demonstrated generating base load power using conventional steam turbine by CSP using parabolic troughs. They store sun’s thermal energy using a proprietary thermic fluid and use them during night times to generate continuous power. The company offers to set up CSP plants of various capacities from 15Mw up to 500Mw.

Friday, August 3, 2012

Solar Hydrogen for homes and cars.


Renewable Hydrogen offers the most potential energy source of the future for the following reasons. Hydrogen has the highest heat value compared to rest of the fossil fuels such as Diesel, petrol or butane. It does not emit any greenhouse gases on combustion. It can readily be generated from water using your roof mounted solar panels. The electrical efficiency of fuel cell using Hydrogen as a fuel is more than 55% compared to 35% with diesel or petrol engine. It is an ideal fuel that can be used for CHP applications. By properly designing a system for a home, one can generate power as well as use the waste heat to heat or air-condition your home. It offers complete independence from the grid and offers complete insulation from fluctuating oil and gas prices. By installing a renewable Hydrogen facility at your home, you can not only generate Electricity for your home but also fuel your Hydrogen car. The system can be easily automated so that it can take care of your complete power requirement as well as your fuel requirement for your Hydrogen car. Unlike Electric cars, you can fill two cylinders of a Hydrogen car which will give a mileage of 270miles.You can also charge your electric car with Fuel cell DC power. Renewable Hydrogen can address all the problems we are currently facing with fossil fuel using centralized power generation and distribution. It will not generate any noise or create any pollution to the environment. It does not require large amount of water. With increasing efficiency of solar panels coming into the market the cost of renewable Hydrogen power will become competitive to grid power. Unlike photovoltaic power, the excess solar power is stored in the form of Hydrogen and there is no need for deep cycle batteries and its maintenance and disposal. It is a one step solution for all the energy problems each one of us is facing. The only drawback with any renewable energy source is its intermittent nature and it can be easily addressed by building enough storage capacity for Hydrogen. Storing large amount of energy is easy compared to battery storage. The attached ‘You Tube’ video footages show how Solar Hydrogen can be used to power your home and fuel your Hydrogen car. Individual homes and business can be specifically designed based on their power and fuel requirements.

Thursday, August 2, 2012

Global warming and man-made greenhouse gas.


There is a raging debate going on around the world especially in US about the global warming and its causes, among scientists and the public alike. When IPCC released its findings on the connection between greenhouse gas emission and the global warming and its disastrous consequences, there was an overwhelming disbelief and skepticism in many people. In fact many scientists are skeptical even now about these findings and many of them published their own theories and models to prove their skepticism with elaborate ‘scientific explanations’. I am not going into details whether greenhouse gas emission induced by human beings causes the globe to warm or not, but certainly we have emitted billions of tons of Carbon in the form of Carbon dioxide into the atmosphere since industrial revolution. Bulk of these emissions is from power plants fueled by Coal, oil and gas. Why power plants emit so much Carbon into the atmosphere and why Governments around the world allow it in the first place? When the emission of Oxide of Nitrogen and Sulfur are restricted by EPA why they did not restrict Oxides of carbon? The reason is very simple. They did not have a technology to generate heat without combustion and they did not have a technology to generate power without heat. It was the dawn of industrial revolution and steam engines were introduced using coal as a fuel. The discovery of steam engines was so great and nobody was disturbed by the black smoke it emitted. They knew very well that the efficiency of a steam engine was low as shown by Carnot cycle, yet steam engine was a new discovery and Governments were willing to condone Carbon emission. Governments were happy with steam engine because it could transport millions of people and goods in bulk across the country and Carbon emission was not at all an issue. Moreover carbon emission did not cause any problem like emission of oxides of Sulfur because it was odorless, colorless and it was emitted above the ground level away from human sight. However the effect of Carbon is insidious. Similarly, power generation technology was developed by converting thermal energy into electrical energy with a maximum efficiency of 33%.This means only 33% of the thermal energy released by combustion of coal is converted into electricity. When the resulting electricity is transmitted across thousands of kilometers by high tension grids, further 5-10% power is lost in the transmission. When the high tension power is stepped down through sub stations to lower voltage such as 100/200/400V further 5% power is lost. The net power received by a consumer is only 28% of the heat value of the fuel in the form of electricity. The balance 67% of heat along with Greenhouse gases from the combustion of coal is simply vented out into the atmosphere. It is the most inefficient method to generate power. Any environmental pollution is the direct result of inefficiency of the technology. Governments and EPAs around the world ignore this fact.Thanks to President Obama who finally introduced the pollution control bill for power plants after 212 years of industrial revolution. Still this bill did not go far enough to control Carbon emission in its current form. Instead of arguing whether globe is warming due to emission of Carbon by human beings or not, Scientists should focus on improving the science and technology of power generation. For example, the electrical efficiency of a Fuel cell is more than 55% compared to conventional power generation at 33% and emits reduced or no carbon. Recent research by MIT shows that such conversion of heat into electricity can be achieved up to 90% compared to current levels of 35%.Had we developed such a technology earlier, probably we will not be discussing about GHG and global warming now. MIT research group is now focusing on developing new Thermophotovoltaics and according to their press release: “Thermal to electric energy conversion with thermophotovoltaics relies on radiation emitted by a hot body, which limits the power per unit area to that of a blackbody. Micro gap thermophotovoltaics take advantage of evanescent waves to obtain higher throughput, with the power per unit area limited by the internal blackbody, which is n2 higher. We propose that even higher power per unit area can be achieved by taking advantage of thermal fluctuations in the near-surface electric fields. For this, we require a converter that couples to dipoles on the hot side, transferring excitation to promote carriers on the cold side which can be used to drive an electrical load. We analyze the simplest implementation of the scheme, in which excitation transfer occurs between matched quantum dots. Next, we examine thermal to electric conversion with a glossy dielectric (aluminum oxide) hot-side surface layer. We show that the throughput power per unit active area can exceed the n2 blackbody limit with this kind of converter. With the use of small quantum dots, the scheme becomes very efficient theoretically, but will require advances in technology to fabricate.” Ref:J.Appl.Phys. 106,094315c(2009); http://dx.doi.org/10.1063/1.3257402 “Quantum-coupled single-electron thermal to electric conversion scheme”. Power generation and distribution using renewable energy sources and using Hydrogen as an alternative fuel is now emerging. Distributed energy systems may replace centralized power plants in the future due to frequent grid failures as we have seen recently in India. Most of the ‘black outs’ are caused by grid failures due to cyclones, tornadoes and other weather related issues, and localized distribution system with combined heat and power offers a better alternative. For those who are skeptical about global warming caused by man-made greenhouse gases the question still remains, “What happened to billions of tons of Caron dioxide emitted into the atmosphere by power plants and transportation since industrial revolution?”.

Saturday, July 28, 2012

Can alternative energy combat global warming?


The world is debating on how to reduce carbon emission and avert the disastrous consequences of global warming. But the emissions from fossil fuels continue unabated while the impact of global warming is being felt all over the world by changing weathers such as flood and draught. It is very clear that the current rate of carbon emission cannot be contained by merely promoting renewable energy at the current rate. Solar, wind, geothermal, ocean wave and OTEC (ocean thermal energy conversion) offer clean alternative energy but currently their total combined percentage of energy generation is only less than 20% of the total power generation. The rate of Carbon reduction by renewable energy do not match the rate of Carbon emission increase by existing and newly built fossil power generation and transportation, to maintain the current level of Carbon in the atmosphere. The crux of the problem is the rate of speed with which we can reduce the Carbon emission in the stipulated time frame. It is unlikely to happen without active participation of industrialized countries such as US, China, India, Japan, EU and Australia by signing a legally binding agreement in reducing their Carbon emissions to an accepted level. However, they can reduce their emissions by increasing the efficiency of their existing power generation and consumption by innovative means. One potential method of carbon reduction is by substituting fossil fuels with biomass in power generation and transportation. By using this method the energy efficiency is increased from current level of 33% to 50-60% in power generation by using gasification technologies and using Hydrogen for transportation. The Fixed carbon in coal is about 70% while the Carbon content in a biomass is only 0.475 X B (B-mass of oven-dry biomass). For example, the moisture content of a dry wood is about 19%,which means the Carbon mass is only 38% in the biomass. To substitute fossil fuels, the world will require massive amounts of biomass. The current consumption of coal worldwide is 6.647 billion tons/yr (Source:charts bin.com)and the world will require at least 13 billion tons/yr of biomass to substitute coal .The total biomass available in the world in the form of forest is 420 billion tons which means about 3% of the forest in the world will be required to substitute current level of coal consumption. This is based on the assumption that all bioenergy is based on gasification of wood mass. But in reality there are several other methods of bioenergy such as biogas, biofuels such as alcohol and bio-diesel from vegetable oils etc, which will complement biogasification to reduce Carbon emission. Another potential method is to capture and recover Carbon from existing fossil fuel power plants. The recovered Carbon dioxide has wider industrial applications such as industrial refrigeration and in chemical process industries such as Urea plant. Absorption of Carbon dioxide from flue gas using solvents such as MEA (mono ethanolamine) is a well established technology. The solvent MEA will absorb Carbon dioxide from the flue gas and the absorbed carbon dioxide will be stripped in a distillation column to separate absorbed carbon dioxide and the solvent. The recovered solvent will be reused. The carbon emission can be reduced by employing various combinations of methods such as anaerobic digestion of organic matters, generation of syngas by gasification of biomass, production of biofuels, along with other forms of renewable energy sources mentioned above. As I have discussed in my previous articles, Hydrogen is the main source of energy in all forms of Carbon based fuels and generating Hydrogen from water using renewable energy source is one of the most potential and expeditious option to reduce Carbon emission.