Monday, August 25, 2014
Thursday, April 18, 2013
Water and energy are two critical issues that will determine the future of humanity on the planet earth. They determine the security of a nation and that is why there is an increasing competition among nations to achieve self-sufficiency in fresh water and clean energy. But these issues are global issues and we need collective global solutions. In a globalised world the carbon emission of one nation or the effluent discharged into the sea from a desalination plant changes the climate of the planet and affects the entire humanity. It is not just a problem of one nation but a problem of the world. The rich and powerful nations should not pollute the earth, air and sea indiscriminately, hoping to achieve self-sufficiency for themselves at the cost of other nations. It is very short sighted policy. Such policies are doomed to fail over a period of time. Next generation will pay the price for such policies. Industrialised countries and oil rich countries should spend their resources on research and development than on weapons and invent new and innovative solutions to address some of the global problems such as energy and water. With increasing population and industrialisation the demand for energy and water is increasing exponentially. But the resources are finite. It is absolutely essential that we conserve them, use them efficiently and recycle them wherever possible so that humanity can survive with dignity and in peace. It is possible only by innovation that follows ‘Nature’s path. The earth’s climate is changing rapidly with unpredictable consequences .Many of us are witnessing for the first time in our lives unusual weather patterns such as draughts, flash flooding, unprecedented snow falls, bush fires, disease and deaths. Although we consider them as natural phenomena there is an increasing intensity and frequency that tells us a different story. They are human induced and we human beings cause these unprecedented events. When scientists point out human beings cause the globe to warm there were scepticism. We never believed we were capable of changing the entire weather system of the globe. We underestimate our actions. By simply discharging effluent from our desalination plants into the sea, can we change the salinity of the ocean or by burning coal can we change the climate of the world? The answer is “Yes” according to science. Small and incremental pollution we cause to our air and water in everyday life have dramatic effects because we disturb the equilibrium of the Nature. In order to restore the equilibrium, Nature is forced to act by changing the climate whether we like it or not. Nature always maintains“equilibrium” that maintains perfect balance and harmony in the world. If any slight changes are made in the equilibrium by human beings then Nature will make sure such changes are countered by a corresponding change that will restore the equilibrium. This is a natural phenomenon. The changes we cause may be small or incremental but the cumulative effect of such changes spanning hundreds of years will affect the equilibrium dramatically. We depend on fossil fuels for our energy needs. These fossils were buried by Nature millions of years ago. But we dig deep into the earth, bring them to surface and use them to generate power, run our cars and heat our homes. Our appetite for fossil fuels increased exponentially as our population grew. We emitted Carbon into the atmosphere from burning fossil fuels for hundreds of years without many consequences. But the emissions have reached a limit that causes a shift in Nature’s equilibrium and Nature will certainly act to counter this shift and the consequences are changes in our weather system that we are currently witnessing. The only way to curtail further Carbon emission into the atmosphere is to capture the current Carbon emissions and convert them into a fuel so that we can recycle them for further power generations without adding fresh fossil fuel into the system while meeting our energy demands. We can convert Carbon emissions into a synthetic natural gas (SNG) by using Hydrogen derived from water. That is why I always believe ‘Water and energy are two sides of the same coin’. But cost of Hydrogen generation from water will be high and that is the price we will have to pay to compensate the changing climate. Sooner we do better will be the outcome for the world. In other word the cost of energy will certainly go up whether we price the Carbon by way of trading or impose Carbon tax or pay incentives for renewable energy or spend several billions of dollars for an innovative technology. There is no short cut. This is the reality of the situation. It will be very difficult for politicians to sell this concept to the public especially during election times but they will have no choice. Similarly serious shortage for fresh water in many parts of the world will force nations to desalinate seawater to meet their growing demand. Saudi Arabia one of the largest producers of desalinated water in the world is still planning for the highest capacity of 600,000m3/day. This plant will discharge almost 600,000 m3/day of effluent back into the sea with more than double the salinity of seawater. Over a period of time the salinity of seawater in the Gulf region has increased to almost 40% higher than it was a decade ago. What it means is their recovery of fresh water by desalination will decrease or their energy requirement will further increase. Any increase in salinity will further increase the fossil fuel consumption (which they have in plenty) will increase the Carbon emission. It is a vicious cycle and the entire world will have to pay the price for such consequences. Small island nations in pacific will bear the brunt of such consequences by inundation of seawater or they will simply disappear into the vast ocean. Recent study by NASA has clearly demonstrated the relationship between the increasing salinity of seawater and the climate change. According to Amber Jenkins Global Climate Change Jet Propulsion Laboratory: “We know that average sea levels have risen over the past century, and that global warming is to blame. But what is climate change doing to the saltiness, or salinity, of our oceans? This is an important question because big shifts in salinity could be a warning that more severe droughts and floods are on their way, or even that global warming is speeding up... Now, new research coming out of the United Kingdom (U.K.) suggests that the amount of salt in seawater is varying in direct response to man-made climate change. Working with colleagues to sift through data collected over the past 50 years, Peter Stott, head of climate monitoring and attribution at the Met Office in Exeter, England, studied whether or not human-induced climate change could be responsible for rises in salinity that have been recorded in the subtropical regions of the Atlantic Ocean, areas at latitudes immediately north and south of Earth’s tropics. By comparing the data to climate models that correct for naturally occurring salinity variations in the ocean, Stott has found that man-made global warming -- over and above any possible natural sources of global warming, such as carbon dioxide given off by volcanoes or increases in the heat output of the sun -- may be responsible for making parts of the North Atlantic Ocean more salty. Salinity levels are important for two reasons. First, along with temperature, they directly affect seawater density (salty water is denser than freshwater) and therefore the circulation of ocean currents from the tropics to the poles. These currents control how heat is carried within the oceans and ultimately regulate the world’s climate. Second, sea surface salinity is intimately linked to Earth’s overall water cycle and to how much freshwater leaves and enters the oceans through evaporation and precipitation. Measuring salinity is one way to probe the water cycle in greater detail.” It is absolutely clear that the way we generate power from fossil fuels and the water we generate from desalination of seawater cannot be continued as business as usual but requires an innovation. New technologies to generate power without emitting Carbon into the atmosphere and generating fresh water from seawater without dumping the highly saline effluent back into the sea will determine the future of our planet. Discharge of concentrated brine into sea will wipe out the entire fish population in the region. The consequences are dire. Oil rich countries should spend on Research and Developments and find innovative ways of desalinating seawater with zero discharge of effluent instead of investing massively on decades old technologies and changing the chemistry of the ocean and the climate forever.
Monday, July 16, 2012
Friday, March 2, 2012
Seawater is an inexhaustible source of Hydrogen but the cost of generating Hydrogen from seawater is much higher compared to normal tap water. The quality of water should have a minimum electric conductivity at 0.1 micro Siemens/cm for electrolysis. Even our tap water is not up to this purity and it requires further purification. The electric conductivity of seawater is about 54,000 micro Siemens/cm.The conductivity increases due to the presence of dissolved salts. But seawater can be desalinated using the process of distillation or by the process called ‘reverse osmosis’. In both the above processes, desalination requires a large input of energy in the form of thermal or electrical. Currently the source of such energy comes from fossil fuels, which is one the biggest emitters of greenhouse gas emission. Many countries in the Middle East have shortage of fresh water and most of these countries depend on desalination of seawater for their fresh water requirements. The cost of desalinated water varies from $ 1.00 to $ 1.75/m3 depending upon the capacity, location and the cost of energy. The fresh water for potable purpose normally has a TDS (Total dissolved solids) of 500ppm (parts per million) or less and this can further be lowered to a required level using reverse osmosis. Currently Hydrogen is generated as a by-product on an industrial scale by electrolysis of saturated sodium chloride brine during the production of Caustic soda. Chlorine is another by-product in the above process. Most of Caustic soda manufacturers use Hydrogen as a fuel or for the production of Hydrochloric acid. But there is an opportunity in caustic soda plants to use Hydrogen to generate more electricity using PEM (Proton exchange membrane) Fuel cell suitable for their electrolysis. This will assist these industries to reduce their energy consumption, which is one of the highest in Chemical industries. Alternatively, offshore wind turbines can be installed to generate power for seawater desalination and Hydrogen production. Offshore wind turbines generate 50% more energy than onshore wind turbines. An integrated process to generate fresh water, Hydrogen using wind turbine is an interesting renewable energy application. The stored Hydrogen can used to generate electricity in remote islands where diesel is used as a fuel. Most of the island in Pacific use diesel predominantly for boat as well as for power generators at exorbitant costs. The wind velocity in such islands is good to generate cheap and clean electricity. For example, the island of PNG has a severe power shortage and it is well located near Coral Sea, which has one of the highest wind velocities in Pacific Ocean. An average wind velocity of 7mts/sec and above is an ideal location for wind turbines. Since these islands are small with less population, wind generated Hydrogen is an ideal solution for their power problems. They can also desalinate seawater to supply drinking water using wind generated power. In fact they can also use Hydrogen as a fuel for their boats and generate power for their cold storage for fisheries. International financial institutions and local banks should come forward to fund such projects instead of funding diesel boats and generators. These islands have pristine water and abundant fish and their main income is only tourism. Sun, Sand and wind is an ideal combination to generate renewable power all round the year and for tourism industry. It is an opportunity these islands cannot afford to miss. The author is personally involved in a wind based Hydrogen solution for a small island in pacific. The people of this island welcome such projects because it guarantees them an uninterrupted supply of clean power and drinking water. Otherwise they have to sell most of fish catches in a nearby city to buy diesel and drinking water just to survive!