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There is a great deal of misconception about desalination of seawater and the word ‘desalination’ is taken literally as a method of separating  fresh water from seawater but not the separation of salt from seawater. The main focus here is only about recovery of fresh water from seawater or from any saline water sources but not salt. In fact separation of salt from seawater is also known as desalination or desalting. The reason for this misconception is because fresh drinking water is in demand and people are concerned only with fresh water and not the salt. There is a huge demand for fresh drinking water all over the world. Increasing population, large scale usage of fresh water by industries, pollution of fresh water by domestic and industrial effluents, failure of monsoon or seasonal rains due to climate change are some of the factors that contributes to water shortage. There is also a demand for water by agriculture industry both in terms of quality and quantity. Bulk of the ground water is used as a main source of fresh water by agriculture industries in many countries.

But sea water also contains number of minerals or salts which have greater economic and commercial value. In terms of quantity their presence is small, only 3.5% and the rest 96.5% is fresh water. For example Chemical industries such as Caustic soda and Soda ash plants use salt as their raw material. But they also use de-ionized water to dissolve salt to produce brine which is their feed stock.

Therefore Chemical plants are the largest users of seawater in terms of salt as well as fresh water. Power plants mainly located on seashore also use large quantity of de-ionized or desalinated water for boilers and for cooling towers.

Sea is now becoming a great source of fresh water as the inland water supply is becoming scarcer due to dwindling water table by drought or flooding by too much rains, pollution by industries etc. In earlier days seawater was the only source of common salt known as Sodium chloride produced by solar evaporation. Bulk of the salt is till used by this method. Therefore it is logical to locate a chemical plant and a power plant side by side so that seawater can be utilized efficiently.

CEWT (Australian company) has developed a new desalination technology called ‘CAPZ desalination technology’ that can generate fresh water as well as Sodium chloride brine simultaneously which is suitable for Caustic soda/Soda ash production. They can integrate such a facility with a skid mounted Chlorine plant of smaller capacities. This plant can generate large volume of drinking water (WHO standard) as a by-product that can be supplied to municipalities and agriculture industries.

Locating large scale solar salt pans near such a facility will be a problem because it requires a huge area of arid land with good wind velocity and it takes nearly a year to harvest the salt.

Using CAPZ desalination technology one can generate saturated Sodium chloride brine of 315 gpl concentration as well as fresh drinking water directly from seawater. The brine is purified to meet the specifications required by membrane Electrolysis for the production of Caustic Soda. The same brine can also be used for the production of Soda ash using Solvay process.

It is no longer necessary to produce brine from solar salt. Solar salt requires vast area of arid land with good wind velocity and least rain fall and large manual labour force to work under harsh conditions; it is a very slow process and takes almost a year to harvest the salt, which is full of impurities and requires elaborate purification process during the production of Caustic Soda. Such purification process generates huge volume of solid waste for disposal. Chlor-alkali industry is one of the most polluting industries in the world. In fact these impurities can be converted into more value added products such as recovery of Magnesium metal or recovery of Potassium salts. CAPZ technology is developing a ZLD (zero liquid discharge) desalination process where the effluent containing the above impurities such as Calcium, Magnesium and Sulphates are converted into value added products. By recovering more such salts from seawater one can recover additional fresh water. Therefore desalination of sea water is now emerging as an integral part of Chlor-alkali industry. By such integration Chlor-alkali can become a major player is meeting fresh drinking water of a nation.

skid mounted Chlorine plantSkid mounted Cl2 planElectrolysis plant by Thyssen krupBy careful integration and co-location of a desalination plant, Caustic soda plant, Food and pharmaceutical grade salt plant and a power plant  on a sea shore will be a win situation for everybody involved.

Let us take a specific case study of setting up a Caustic soda plant, a captive power plant and a desalination facility.

A typical skid mounted Chlorine plant will have the following configuration:

Capacity of Caustic Soda: 50.7 Mt/day (100% basis)

Capacity of Chlorine        : 45.00 Mt/day (100% basis)

Hydrogen production        : 14,800m3/day (100% basis)

A typical usage of Vacuum salt for such skid mounted Chlorine plant will be about 76.50 Mt/day with a power consumption of 2.29 Mwhr/Mt of NaOH (100%).

A captive power plant of capacity 200Mw will be able to supply necessary power for both Desalination facility as well as Caustic soda plant.

The CAPZ desalination facility can supply a saturated sodium chloride brine (315gpl concentration) 245 Mt/day and 9122 m3/day of fresh drinking water from the desalination plant. This water can be used for boiler feed in the power plant. Surplus water can be supplied as drinking water meeting WHO specifications.

The Hydrogen gas the by-product from caustic soda plant with capacity of 14,800 m3/day can be used to generate clean power using a Fuel cell. The power generated from Fuel cell will be about 20 Mwhr/day that can be supplemented for the Caustic soda production thereby reducing the power consumption from 2.29Mwhr to 1.46 Mwhr/Mt of NaOH (100%)

By careful integration of a large (ZLD) desalination facility with caustic soda plant and power plant it will be possible in future to generate a clean energy using Hydrogen, a by-product of Caustic soda plant and solar thermal plant to produce chemicals in a clean and environmentally sustainable manner.

For further information on CAPZ technology, please contact ahilan@clean-energy-water-tech.com.

 

 

 

“The intuitive mind is a sacred gift and the rational mind is a faithful servant.We have created a society  that honors the servant and has forgotten the gift” – Albert Einstein.

United Nation’s panel on climate change (IPCC) recently confirmed that climate change is real, it is man-made and it is irreversible and if nations do not act now then they will have to face catastrophic climate events in the future. They were categorical and unequivocal in their statements this time. They have come to this conclusion because science has not demonstrated how to   capture carbon emission and sequester them under the earth using current technologies. Scientists neglected carbon emissions while generating power using fossil fuels for decades because they had no idea what would be the consequences of such emissions in the future. It is a clear example how a human mind has a limited capacity to conceive an idea “holistically” but has a capacity to satisfy human needs temporarily without knowing the unforeseeable consequences. When human beings interfere with Nature in the name of Science there are consequences to face and a price to pay because Nature is nothing but the manifestation of the highest intelligence. A real science can be no further than asserting this truth. Ignorance when combined with greed can be a deadly combination and the consequences will be costly and to be paid dearly by generations to come. Carbon emission and climate change is one such issue. Science has improved human life on earth in so many ways but at the same time they also have created many side effects which can be identified only after decades of their use. When they are identified it is often too late and causes irreversible damage to system or nature. Any irreversible change human beings cause in Nature will have its own consequences. Science has shown Carbon is the backbone of all organic matter on planet earth whether it is DNA of a human being or a glittering diamond from deep under the earth. The same Carbon reveals the age of a skeleton of a Dinosaur  buried millions of years ago. Science is a powerful tool but it also has two sides, benign and malign. The power to discriminate between the good and bad is the fundamental pre-requisite of science. Carbon plays an indispensible role in the natural world due to its unique atomic structure and ease with which it can build molecules especially with hydrogen. That is why hydrocarbon is playing such an important role in human civilization and it is not easy to substitute it with another candidate without a long term research and development work. But we have a very short time to discover a substitute for hydrocarbon which can serve our current purposes. Few nuclear power plants around the world can satisfy the growing demand for the electricity without any carbon emission but their long term consequences are unknown. The result of a thermo-nuclear explosion over Hiroshima and Nagasaki are the grim reminder of such consequences. When earth converts organic matter into a fossil over a period of millions of years deep under the earth, it gives us a clue why Nature has buried them and not left them on the surface of the earth. But that did not deter human beings from digging them out and burning them to generate heat to meet their temporary energy needs without realizing the long term consequences of such actions. Many technologies have become obsolete over a period of time for various reasons but some of them lingered long enough to create long lasting consequences and there are many evidences in history to emphasize this truth. Power generation using fossil fuel is one such clear example of a technological bungle. It only confirms the inadequacy of human knowledge.  It also reveals the temporary nature of such inventions stemming from temporary nature of human life. Science also has changed dramatically in the last few decades and it no longer serves the original purpose of unraveling and understanding the mysteries of Nature but caters and serves to the greed and dominance of selected rich and powerful people and the nations in the world. Science has become a tool to create material wealth and power rather than to understand nature and apply them into our lives in a compatible way and to enrich human life. These experiences have taught one important lesson. Any scientific discovery when applied in real life must be “holistic” and be compatible with Nature and should follow Natural laws. When science becomes a wealth creating tool then any knowledge born out of such science can only serve to create wealth often at the cost of Nature. That is why rich and powerful corporate and nations spend billions of dollars in such wealth creating discoveries rather than on discoveries that address human problems of the world that may not return their investment in time. The anomaly is more they invest on wealth creating science more damage they cause to earth and human life. Such discoveries serve only one purpose namely “the wealth creation “. Wealth and power has overtaken science and knowledge. Climate change has become a serious issue and it is absolutely clear that CO2 in the atmosphere has increased to the current level for the first time in millions of years and human beings have contributed greatly to this increase. Yet, nations around the world are unable to come to-gather and agree on how to reduce such emissions. The only way to solve this issue is to use Science as a tool which created this problem in the first place. When steam engine was invented it was considered as the dawn of industrial revolution: when electricity generation using electro-magnetism was invented it was hailed as a land mark in scientific development. When power was generated using fossil fuel to accelerate the industrial growth very little attention was paid to the carbon emission. When huge quantities of sea water was used to cool the cooling towers in fossil fuel powered or nuclear power plants very little attention was paid to the discharge of effluent in to the sea. When large desalination plants were set up to quench the thirst of oil rich countries very little attention was paid to the toxic discharge of effluent in to the sea. What was missing in all the above developments was the negligence of Nature by discharge of emissions or effluents into the Natural world. We have taken Nature for granted and treated her with great indignity and contempt. Few decades ago Scientists were able to make remarkable discoveries using only their mind as a tool and theorizing certain concepts. They were abstract in nature but were validated whenever applied in practice. There were no big investments by Governments or companies on scientific discoveries, no Intellectual property portfolios, no personal ownership, no disputes on infringement as to who owns and what. Today scientific inventions and intellectual properties are the biggest assets and monopolies of few corporate and nations.  Several hundred billions are spent on patents, trademarks and copy rights to stamp their authorities and ownerships. But where such knowledge came from? Who pays for the consequences of ill -conceived scientific discoveries that prove disastrous in the long run? Who can sue them when such technologies are passed on to several generations without knowing their long term consequences? Science is now suggesting methods to address carbon emission using various renewable energy sources such as solar, wind, biomass etc. But these methods often use capital intensive equipments to use such energy even though Nature provides them free of cost. Such equipments also require large energy input to produce which again comes from fossil fuel maintaining the level of CO2 in the atmosphere. The investment on renewable energy has come down by nearly 70% according to latest news and many countries are gearing up to step up their fossil fuel production in the name of “energy security” simply because they have become “addicted “to old ways of living. In fact there is too much at stake for these countries and they are stubbornly sticking to old ideas. Science has become useless in addressing climate change because it is no longer about science but about nation’s security and maintaining material wealth of the citizens of a particular nation and the popularity of politicians among the ignorant masses and  winning their elections and holding to their power. Sun is the only source of energy on the planet earth and all other forms of energy such as wind and biomass etc are only by-products of sun.  Current power generating technologies heavily depends of conversion of thermal energy into electrical energy and the source of thermal energy is by fossil fuel or nuclear. Recently light energy from sun is converted directly into electrical energy using photovoltaics. They also use thermal energy of the sun using solar concentrators to generate power in conventional way using turbines. But high initial cost, lack of energy storage technologies and intermittent nature of renewable sources increases the cost of energy compared to conventional coal fired power and alternative energy has created an uncertainty in the power industry. Energy industry is now at the cross road and it has divided people into two categories; one group accepts science of global warming and climate change and advocate substituting fossil fuel with carbon free energy sources and another group express skepticism over climate science and support fossil fuel energy sources in order to continue and maintain the industrial growth and employment. If countries like US and Australia who have rich deposits of high grade coal and depend heavily on coal based power plants and industries then they have an option to increase the efficiency of coal utilization by way of emission reduction. For example they can reduce carbon emission substantially using gasification technologies. In fact, under certain special conditions it is possible to generate syngas from coal with highest Hydrogen content (even up to CO: H2 ratio of 20:80).This will increase not only the calorific value of syngas but also reduce carbon emission. Companies like GE, USA are developing special gas turbines for syngas with high hydrogen content. Alternatively conversion of coal into synthetic natural gas (SNG) can reduce the carbon emission without dispensing with coal completely. Renewable hydrogen is a potential long term substitute for fossil fuel both for power industry and transportation. But it requires special handling due to its high explosive nature and it is often easier to handle it with a mix of hydrocarbon such as Methane or Carbon monoxide. Fuel cell is an emerging technology that can use hydrogen for power generation as well as for transportation. However it requires expensive catalysts and they are currently confined to smaller applications in power industry. Fuel cell opens up a new way to generate electricity by simply stripping electrons from a hydrogen atom with Platinum and allowing the resulting proton exchange by special membranes in a cell converting chemical energy into an electrical energy. It is certainly a breakthrough in power generation but there is a long way to go before commercializing them on larger scale. It seems Carbon will continue to play an important role for years to come due to its unique nature in the natural world. But high carbon intensity fuel such as coal and current methods of direct combustion will have to be abandoned and substituted with SNG or Syn gas with high hydrogen content by gasifying coal. By this way hydrogen can be introduced into the current energy mix without substantial deviation from using coal while maintaining the carbon emission well within the limit. However a long term strategy will require complete substitution of fossil fuel with renewable hydrogen or with completely a new method of electricity generation such as Fuel cell without using a thermal energy.  Electricity is nothing but a flow of electrons and techniques that are currently used in Fuel cell such as proton exchange membrane should be developed using low cost catalyst and materials on a much larger scale to substitute fossil fuel completely. It is clear that power generation technology should be delinked with using carbon source or combustion for that matter. Combustion of hydrogen electrochemically is an elegant solution but lot of research and development is required. But the stark reality is climate is already changing and the climate change is irreversible and we have to use science to adopt our lives to the changing climate in the future. We cannot capture the carbon and bury them under the earth as Nature does because Nature has not taught us how to do it in a short span of time. The impact of climate change can be minimized or averted depending upon how fast carbon emission is reduced using new technologies. Climate change is an important lesson from which the scientific community should learn how not to interfere with Nature without a complete understanding of it. Sun shine and clean air are not just for rich and powerful but to the entire humanity on the planet. Any scientific discovery should be “holistic” and compatible with Nature and easily accessible to all human beings. Solar and biomass are emerging as alternative technologies to tackle climate change but these simple and holistic solutions were in fact practiced for decades in rural India. Farmers in India feed their cattle with cellulosic fibers (polysaccharides) as a feed and use their waste in the form of “solar” dried cakes (cow dung cakes) as a fuel that has a calorific value of 2100kj (Wikipedia). They also use the waste to generate Methane by anaerobic digestion. These technologies are not new but the challenge is they should to be built on large commercial scales to meet the demand of the growing population in a holistic way. Industrialized countries are now trying to convert the same cellulose (polysaccharides) into industrial alcohol instead of converting corn starch. When plants grow by photosynthesis using sun, it generates starch, lignin, cellulose as well as fatty acids in oil seeds.  It is important to understand that Nature provides them as food for human beings and animals and not as a raw material to generate fuel or energy and that is why “holistic solutions” are the key for the survival of science and technology as well as humanity in the future.

Jet fuel from seawatersynthetic  Crude oil -Pilot plantFT recator for syntehtic crudeRecent news from USA has got the attention of many people around the world. “Scientists with the United States Navy say they have successfully developed a way to convert seawater into jet fuel, calling it a potentially revolutionary advancement. Researchers at the Naval Research Laboratory (NRL) developed technology to extract carbon dioxide from seawater while simultaneously producing hydrogen, and then converted the gasses into hydrocarbon liquid fuel. The system could potentially shave hours off the at-sea refueling process and eliminate time spent away from missions.” They estimate the cost of the jet fuel will be anywhere between $3 and $6 per gallon.  It may not be able to compete with traditional petroleum sources due to high energy requirement. However, the main attraction of this process is to extract Carbon dioxide absorbed by the ocean to avoid acidification and to mitigate climate change while making petrol as a Carbon neutral fuel. Ocean has become a rich source of Carbon (Carbon sink) absorbing excess atmospheric Carbon dioxide caused by human beings. Generating Carbon neutral fuel such as SNG (synthetic natural gas), diesel and petrol from air and sea water will be the fastest way to reduce Carbon from the atmosphere. Probably Governments, business and industries will embarrass this concept much quicker than any other mitigating methods simply because it is a revenue generating proposition with a potential to earn carbon credit.

Carbon-neutral fuel is a synthetic fuel (including methanegasolinediesel fueljet fuel or ammonia) that is produced using  carbon dioxide recycled from power plant flue exhaust gas or derived from carbonic acid in seawater  and renewable Hydrogen. Such fuels are potentially carbon-neutral because they do not result in a net increase in atmospheric greenhouse gases.  It is a Carbon capture and recycling (CCR) process.

“To the extent that carbon-neutral fuels displace fossil fuels, or if they are produced from waste carbon or seawater carbonic acid, and their combustion is subject to carbon capture at the flue or exhaust pipe, they result in negative carbon dioxide emission and net carbon dioxide removal from the atmosphere, and thus constitute a form of greenhouse gas remediation. Such power to gas carbon-neutral and carbon-negative fuels can be produced by the electrolysis of water to make hydrogen used in the Sabatier reaction to produce methane which may then be stored to be burned later in power plants as synthetic natural gas, transported by pipeline, truck, or tanker ship, or be used in gas to liquids processes such as the Fischer–Tropsch  (FT) process to make traditional fuels for transportation or heating.

Carbon-neutral fuels are used in Germany and Iceland for distributed storage of renewable energy, minimizing problems of wind and solar intermittency, and enabling transmission of wind, water, and solar power through existing natural gas pipelines. Such renewable fuels could alleviate the costs and dependency issues of imported fossil fuels without requiring either electrification of the vehicle fleet or conversion to hydrogen or other fuels, enabling continued compatible and affordable vehicles.A 250 kilowatt synthetic methane plant has been built in Germany and it is being scaled up to 10 megawatts.” (Wikipedia).

We have been writing about renewable hydrogen (RH) for the past couple of years and often use the phrase, “Water and energy are two sides of the same coin” because we can mitigate climate change using renewable hydrogen (RH) even while the fossil fuel economy can carry on as usual.

By generating Carbon neutral fuels using excess Carbon from air and sea and hydrogen from water (even seawater) using renewable energy sources, the problem of global warming and climate change can be solved because we will not be adding any further Carbon into the atmosphere than what it is today!

Instead of generating solar and wind power and storing them in batteries it will be prudent to generate Carbon neutral fuel from CO2 already available in the system and use them as usual. Meanwhile Hydrogen based power generation and transportation   can be developed as a long term solution.

Fossil-fired power plants produce CO2 (Carbon dioxide) which could be captured and converted to CO (Carbon monoxide) for production of synthetic fuels. CO2 can be converted to CO by the Reverse Water Gas Shift Reaction, CO2 + H2–> CO + H2O. CO could then be used in the F-T reaction with additional hydrogen from water-splitting to produce synthetic fuel such as diesel and petrol as carbon neutral fuels.

 Synthetic fuel by CO2 Capture + H2 from Water-splitting:

Reverse Water Gas Shift                          CO2 + H2 —->  CO + H2O

F-T reaction                                             CO + 2H2 —-> CH2 + H2O

 

Water-splitting                              3H2O + Energy –> 3H2 + 3/2O2

Net reaction                         CO2 + H2O + Energy —>CH2 + 3/2O2

 

In this case, no coal is needed at all, and CO2 is consumed rather than produced. The excess O2 would be used in the fossil power plant that provides the CO2, simplifying CO2 capture. There is currently considerable effort underway on developing CO2 capture systems for new and extant power plants. The increasing concern with Global Climate Change suggests that there is a reasonable likelihood of such plants operating in the timeframe associated with synthetic fuel from carbon dioxide. Such a synergistic system has the potential to significantly reduce our current emissions of CO2 since the carbon in the coal is used once for power production and then again for liquid hydrocarbon fuel synthesis.

Synthetic fuel plant with capacities as low as 1000 barrels/day are commercially feasible using specially designed micro-reactors as shown in the attached photograph (ref: Velocys). Utilizing carbon dioxide from sea and air is the smartest way to mitigate climate change while maintaining fossil fuel based power plants and automobiles without any change or modifications. The same technique can also be applied for biomass gasification plants.

 

Brine dischage in Gulfchemical usage in desalinationDesal capacityDesalination capacity in the worldsalinity levels in Gulf regionwater cycle

Water and energy are two critical issues that will decide 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 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 creative 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 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 now 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 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 saltness, 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 decide 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 their riches on Research and Developments to find innovative ways of desalinating seawater instead of investing massively on decades old technologies and changing the chemistry of the ocean and the climate forever.

 

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 need 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 200miles.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 need 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 footage 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.

Carbon neutral biomass is becoming a potential alternative energy source for fossil fuels in our Carbon constrained economy. More and more waste –to-energy projects is implemented all over the world due to the availability of biomass on a larger scale; thanks to the increasing population and farming activities. New technological developments are taking place side by side to enhance the quality of Biogas for power generation. Distributed power generation using biogas is an ideal method for rural electrification especially, where grid power is unreliable or unavailable. Countries like India which is predominantly an agricultural country, requires steady power for irrigation as well as domestic power and fuel for her villages. Large quantity of biomass in the form of agriculture waste, animal wastes and domestic effluent from sewage treatment plants are readily available for generation of biogas. However, generation of biogas of specified quality is a critical factor in utilizing such large quantities of biomass. In fact, large quantity of biomass can be sensibly used for both power generations as well as for the production of value added chemicals, which are otherwise produced from fossil fuels, by simply integrating suitable technologies and methods depending upon the quantity and quality of biomass available at a specific location. Necessary technology is available to integrate biomass gasification plants with existing coal or oil based power plants as well as with chemical plants such as Methanol and Urea. By such integration, one can gradually change from fossil fuel economy to biofuel economy without incurring very large capital investments and infrastructural changes. For example, a coal or oil-fired power plant can be easily integrated with a large-scale biomass plant so that our dependency on coal or oil can be gradually eliminated.

Generation of biogas using anaerobic digestion is a common method. But this method generates biogas with 60% Methane content only, and it has to be enriched to more than 95% Methane content and free from Sulfur compounds, so that it can substitute piped natural gas with high calorific value or LPG (liquefied petroleum gas). Several methods of biogas purification are available but chemical-free methods such as pressurized water absorption or cryogenic separation or hollow fiber membrane separation are preferred choices.

The resulting purified biogas can be stored under pressure in tanks and supplied to each house through underground pipelines for heating and cooking. Small business and commercial establishments can generate their own power from this gas using spark-ignited reciprocating gas engines (lean burnt gas engines) or micro turbines or PAFCs (phosphoric acid fuel cells) and use the waste heat to air-condition their premises using absorption chillers. In tropical countries like India, such method of distributed power generation is absolutely necessary to eliminate blackouts and grid failures. By using this method, the rural population need not depend upon the state-owned grid supplies but generate their own power and generate their own gas, and need not depend on the supply of rationed LPG cylinders for cooking. If the volume of Bio-methane gas is large enough, then it can also be liquefied into a liquified bio-methane gas (LBG) similar to LNG and LPG. The volume of biomethane gas will be reduced by 600 times, on liquefaction. It can be distributed in small cryogenic cylinders and tanks just like a diesel fuel. The rural population can use this liquid bio-methane gas as a fuel for transportation like cars, trucks, buses, and farm equipment like tractors and even scooters and auto-rickshaws.

Alternatively, large-scale biomass can be converted into syngas by gasification methods so that resulting biomass can be used as a fuel as well as raw materials to manufacture various chemicals. By gasification methods, the biomass can be converted into a syngas (a mixture of Hydrogen and Carbon monoxide) and free from sulfur and other contaminants. Syngas can be directly used for power generation using engines and gas turbines.

Hydrogen rich syngas is a more value added product and serves not only as a fuel for power generation, but also for cooking, heating and cooling. A schematic flow diagram Fig 3,  Fig4 and Fig 6 (Ref: Mitsubishi Heavy Industries Review) shows how gasification of biomass to syngas can  compete with existing fossil fuels for various applications such as for power generation, as a raw material for various chemical synthesis and as a fuel for cooking, heating and cooling and finally as a liquid fuel for transportation. Bio-gasification has a potential to transform our fossil fuel dependant world into Carbon-free world and to help us to mitigate the global warming.

We have used Hydrocarbon as the source of fuel for our power generation and transportation since industrial revolution. It has resulted in increasing level of man-made Carbon into the atmosphere; and according to the scientists, the level of carbon has reached an unsustainable level and any further emission into the atmosphere will bring catastrophic consequences by way of climate change. We have already saw many natural disasters in a short of span of time. Though there is no direct link established between carbon level in the atmosphere and the global warming, there is certainly enough evidence towards increase in the frequency of natural disasters and increase in the global and ocean temeperatures.We have also seen that Hydrogen is a potential candidate as a source of future energy that can effectively substitute hydrocarbons such as Naphtha or Gasoline. However, hydrogen generation from water using electrolysis is energy intensive and the source of such energy can come only from a renewable source such as solar and wind. Another issue with electrolysis of water for Hydrogen generation is the quality of water used. The quality of water used for electrolysis is high, meeting ASTM Type I Deionized Water preferred, < 0.1 micro Siemen/cm (> 10 megOhm-cm).

A unique desalination technology has been developed by an Australian company to generate on site Hydrogen directly from seawater. In conventional seawater desalination technology using reverse osmosis process only 30-40% of fresh water is recovered as potable water with TDS less than 500 ppm as per WHO standard. The balance highly saline concentrate with TDS above 65,000 ppm is discharged back into the sea which is detrimental to the ocean’s marine life. More and more sweater desalination plants are set up all over the world to mitigate drinking water shortage. This conventional desalination is not only highly inefficient but also causes enormous damage to the marine environment.

The technology developed by the above company will be able to recover almost 75% of fresh water from seawater and also able to convert the concentrate into Caustic soda lye with Hydrogen and Chlorine as by-products by electrolysis. The discharge into the sea is drastically reduced to less than 20% with no toxic chemicals. This technology has a potential to revolutionize the salt and caustic soda industries in the future. Caustic soda is a key raw material for a number of chemical industries including PVC.Conventionally, Caustic soda plants all over the world depends on solar salt for their production of Caustic soda.Hydrogne and Chlorine are by-products.Chlrine is used for the production of PVC (poly vinyl chloride) and Hydrogen is used as a fuel.

In the newly developed technology, the seawater is not only purified from other contaminants such as Calcium, Magnesium and Sulfate ions present in the seawater but also concentrate the seawater almost to a saturation point so that it can be readily used to generate Hydrogen on site. The process is very efficient and commercially attractive because it can recover four valuable products namely, drinking water, Caustic soda lye, Chlorine and Hydrogen. The generated Hydrogen can be used directly in a Fuel cell to generate power to run the electrolysis. This process is very ideal for Caustic soda plants that are now located on seashore. This process can solve drinking water problems around the world because potable water becomes an industrial product. The concentrated seawater can also be converted in a salt by crystallization for food and pharmaceutical applications. There is a growing gap between supply and demand of salt production and most of the chemical industries are depending upon the salt from solar pans.

Another potential advantage with this technology is to use wind power to desalinate the water. Both wind power and Hydrogen will form a clean energy mix. It is a win situation for both water industry and the environment as well as for the salt and chemical industries. In conventional salt production, thousands of hectares of land are used to produce few hundred tons of low quality salt with a year-long production schedule. There is a mis match between the demand for salt by large Caustic soda plants and supply from primitive methods of solar production by solar evaporation contaminating cultivable lands.

The above case is an example of how clean energy technologies can change water, salt and chemical industries and also generate clean power economically, competing with centralized power plants fuelled with hydrocarbons. Innovative technologies can solve problems of water shortage, greenhouse gases, global warming, and environmental pollution not only economically but also environmental friendly way. Industries involved in seawater desalination, salt production, chemical industries such as Caustic soda, Soda ash and PVC interested to learn more on this new technology can write directly to this blog address for further information.

Fuel cell technology is emerging as a base-load power generation technology as well as back-up power for intermittent renewable energy such as solar and wind, substituting conventional storage batteries. However, Fuelcell requires a Fuel in the form of Hydrogen of high purity. The advantage of Fuel cell is, its high electrical efficiency compared to conventional fossil fuel power generation technology, using Carnot cycle. Fuel cell is an electro-chemical device like a battery and generates power using electro-chemical redox reaction silently with no gaseous emission, unlike engines and turbines with combustion, rotary movements and gaseous emissions. The fuel Hydrogen can be generated using a renewable energy sources such as solar and wind as described in my previous articles, “Solar Hydrogen for cleaner future” dated 4 July 2012, and “Renewable Hydrogen for remote power supply “dated 28 June 2012.

Alternatively, Hydrogen can also be generated using biomass through Biogas. Biogas is an important source of renewable energy in the carbon constrained economy of today’s world. The biogas can be generated from waste water and agro-waste by anaerobic digestion using enzymes. Biomass such as wood waste can also be gasified to get syngas, a mixture of Hydrogen and Carbon dioxide. In anaerobic digestion, the main product will be methane gas accompanied by carbon dioxide and nitrogen while the main product in gasification will be Hydrogen, carbon monoxide and carbon dioxide and oxides of Nitrogen. Whatever may be the composition of the resulting gas mixture, our focus will be to separate methane or Hydrogen from the above mixture. In anaerobic digestion, the resulting Methane gas has to be steam reformed to get Hydrogen gas suitable for Fuel cell application. In gasification, the resulting Syngas has to be separated into pure Hydrogen and Carbon dioxide so that pure Hydrogen can be used as a fuel in Fuel cell applications. As I have outlined in many of my previous articles, Hydrogen was the only fuel we have used all these years and we are still using it  in the form of Hydrocarbons and it will continue to be the fuel in the future also. The only difference is future Hydrogen will be free from carbon.

We have to discuss two issues to mitigate Carbon emission, and it can be done by 1.Elimination of Carbon from the fuel source. 2. Generation of Renewable and Carbon free clean energy directly from solar and wind. One option  to cut Carbon from the fuel source is to use Biomass as the raw material to generate Hydrogen so that fresh Carbon will not be added  into the atmosphere by emissions .The second option is to generate pure Hydrogen from water by electrolysis using renewable energy such as wind and solar. Environmentally friendly waste-to-energy projects are becoming popular all over the world. But now most of these waste-to-energy projects generate either Biogas (Methane) by anaerobic digestion or Syngas (Hydrogen and Carbon dioxide) by gasification. Both these gases need further purification before they can be used as a fuel for power generation. The Methane content in the Biogas (about 60% methane and 40% Carbon dioxide with other impurities) needs to be enriched to 90% Methane and free from other impurities. The composition of a typical Biogas is shown in table1.

The resulting purified methane gas will be reformed using steam reformation in presence of a catalyst to get syngas; finally Hydrogen should be separated from resulting syngas so that it can be used directly into the Fuelcell.The common Fuel cell used for this application is invariably Phosphoric acid fuel cell.

PAFC uses 100% Phosphoric acid in Silicon carbide matrix as an electrolyte. PAFC is a self-contained unit completely enclosed in a cabin consisting of a gas reformer, Fuellcell power generator, Power conditioning unit and other auxiliaries. The PAFC is of modular construction with capacities ranging from 100Kw up to 500Kw as a single unit. It can be installed outdoor in the open and it can be readily connected to a piped Biogas. It can also be connected to existing piped natural gas or LPG bullet as a stand-by fuel. Any waste-to energy project can be integrated with Fuel cell power generation with CHP application to get greatest economic and environmental benefits. Hydrogen derived from biomass will be an important source of fuel in the future of clean energy; and Fuel cell will become an alternative power generation technology for both stationary power generation and transportation such as Fuel cell car or Hybrid cars.

PAFC is a compact, self-contained power generation unit that is used even for base load power. The electrical efficiency of PAFC  is about 42% .It is suitable for CHP applications so that the total energy efficiency can reach up to 85%.It is ideal for supplying continuous power 24×7 and also to use waste heat for space heating or space air-conditioning with an absorption chiller in CHP applications. The ideal candidates for PAFC power generation using CHP will be hospitals, super markets, Data centers, Universities or any continuous process industry.PAFC is now used as a backup power for large-scale renewable energy project with an access to piped natural gas. A schematic flow diagram of a fuel cell power generation is shown in Fig 3 using biogas at Yamagata sewage treatment plant in Japan. Biomass  based  Fuecell  power generation has a great potential all over the world irrespective of location and size of the country.

PV solar is expanding as a potential renewable energy source for each house, and the cost of solar panels are slowly coming down as the volume of production increases. However, the intermittent nature of solar energy is still an issue, especially for off grid and remote locations. Now solar energy is stored using lead acid batteries for such applications and inverters become part of the system. The capacity of the battery bank is designed to meet the electrical demand and to absorb the fluctuation of the energy generated by solar panels and it varies from place to place. This method stores the electrical energy generated by PV solar in the form of DC current and delivers it in the form of AC current. Though this method is the simplest one for remote locations, storing solar power in the form of Hydrogen is more economical and environmentally friendly in the long run.

Solar energy can directly be used to generate Hydrogen using solid polymer electrolyzers and stored in cyclinders.The stored Hydrogen can then be used to fuel a stationary Fuel cell to generate power on site. One can design a system by integrating various components in such a way; the Hydrogen generated by solar energy is used to generate power on site as and when required. By this method one can generate required power throughout the day 24×7 irrespective of the availability of sun. The system integration involves various components supplied by various manufacturers with various specifications and the success of a system depends on the careful design using data acquired over a time on a specific location.

Many winds to Hydrogen projects also have been tested in locations around the world.NREL (National renewable energy laboratory, USA) has conducted number of tests by integrating various components such as PV solar and wind turbines with Electrolyzers (both PEM electroylzers and alkaline electrolyzers) and Hydrogen IC engines for remote power generation as well as for fuelling vehicles with Hydrogen. Though the cost of this system is still expensive, such integration offers enormous potential as a clean energy source for remote locations without any grid power. When one takes into account the fluctuating oil prices, cost of global warming, cost of power transmissions and losses during long distance power transmission from fossil fuel power plants, Renewable Hydrogen offers the best and sustainable alternative to fossil fuels. Such a system offers complete independence, energy security, reliability and fixed power tariff.

System integration of renewable energy sources for Hydrogen production and on site power generation using Fuel cell or Hydrogen engine is the key to a successful deployment of solar and wind energy for rural electrification and to remote islands. Such system will offer greater return on investment even to supply power to the grid based on power purchase agreements with Government and private companies. Renewable Hydrogen is the only practical solution for clean power of the future and sooner we embrace this integrated solution better for a cleaner future. Government and private companies investing on oil and gas explorations can focus their attention in developing renewable Hydrogen based solutions so that the cost of Hydrogen can become competitive to fossil fuel. Once the cost of Hydrogen reaches parity with cost of fossil fuel then, it will set the beginning of a green revolution in clean energy.

Wind energy is one of the fastest growing renewable energy sources in the world and in 2011 the global market grew by 6% with 40.5 GW new powers brought online, according to Global Wind Report. However storage of intermittent renewable energy is a critical contributing factor in renewable energy development. A study was conducted by University of California for California Energy Commission on the economic and environmental impact of for energy storage technologies and the ways to improve the energy efficiency of wind energy. When there is a strong wind there is no demand for power, and when there is a high demand for power there is no wind. This anomalous supply demand gap demands a reliable way of storing wind power during high wind velocity periods.

They examined for energy storage technologies namely 1.lead acid batteries, 2. Zinc Bromine flow batteries, 3.Hydrogen electrolyzer and Fuel cell storage system and 4.Hydrogen option to fuel Hydrogen cars with Hydrogen. By using NREL (national Renewable Energy laboratory) computer simulation model HOMER  for high wind penetration of 18% in California, they concluded that Hydrogen storage is the most cost-effective than other battery storage technologies and using Hydrogen to fuel Hydrogen cars is economically attractive  than converting Hydrogen into Electricity. The environmental impact of using Hydrogen is benign compared to batteries with their emissions.

“The key findings of this experiments are as follows: Energy storage systems deployed in the context of greater wind power development were not particularly well used (based on the availability of “excess” off-peak electricity from wind power), especially in the 2010 time frame (which assumed 10% wind penetration statewide), but were better utilized–up to 1,600 hours of operation per year in some cases–with the greater (20%) wind penetration levels assumed for 2020.

The levelized costs of electricity from these energy storage systems ranged from a low of $0.41 per kWh—or near the marginal cost of generation during peak demand times—to many dollars per kWh (in cases where the storage was not well utilized). This suggests that in order for these systems to be economically attractive, it may be necessary to optimize their output to coincide with peak demand periods, and to identify additional, value streams from their use (e.g., transmission and distribution system optimization, provision of power quality and grid ancillary services, etc.).

At low levels of wind penetration (1%–2%), the electrolyzer/fuel cell system was either inoperable or uneconomical (i.e., either no electricity was supplied by the energy storage system or the electricity provided carried a high cost per MWh).

In the 2010 scenarios, the flow battery system delivered the lowest cost per energy stored and delivered.  At higher levels of wind penetration, the hydrogen storage systems became more economical such that with the wind penetration levels in 2020 (18% from Southern California), the hydrogen systems delivered the least costly energy storage.

Projected decreases in capital costs and maintenance requirements along with a more durable fuel cell allowed the electrolyzer/fuel cell to gain a significant cost advantage over the battery systems in 2020.

Sizing the electrolyzer/fuel cell system to match the flow battery system’s relatively high instantaneous power output was found to increase the competitiveness of this system in low energy storage scenarios (2010 and Northern California in 2020), but in scenarios with higher levels of energy storage (Southern California in 2020), the electrolyzer/fuel cell system sized to match the flow battery output became less competitive.

The hydrogen production case was more economical than the electrolyzer/fuel cell case with the same amount of electricity consumed (i.e., hydrogen production delivered greater revenue from hydrogen sales than the electrolyzer/fuel cell avoided the cost of electricity, once the process efficiencies are considered).

Furthermore, the hydrogen production system with a higher-capacity power converter and electrolyzer (sized to match the flow battery converter) was more cost-effective than the lower-capacity system that was sized to match the output of the solid-state battery. This is due to economies of scale found to produce lower-cost hydrogen in all cases.

In general, the energy storage systems themselves are fairly benign from an environmental perspective, with the exception of emissions from the manufacture of certain components (such as nickel, lead, cadmium, and vanadium for batteries). This is particularly true outside of the U.S., where battery plant emissions are less tightly controlled and potential contamination from improper disposal of these and other materials is more likely. The overall value proposition for energy storage systems used in conjunction with intermittent renewable energy systems depends on diverse factors:

The interaction of generation and storage system characteristics and grid and energy resource conditions at a particular site The potential use of energy storage for multiple purposes in addition to improving the dependability of intermittent renewable (e.g., peak/off-peak power price arbitrage, helping to optimize the transmission and distribution infrastructure, load-leveling the grid in general, helping to mitigate power quality issues, etc.)

The degree of future progress in improving forecasting techniques and reducing prediction errors for intermittent.  Electricity market design and rules for compensating renewable energy systems for their output”. Hydrogen storage and Hydrogen cars hold the key for future renewable energy industries and Governments and industries should focus on these two key segments.

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