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Showing posts with label seawater. Show all posts
Showing posts with label seawater. Show all posts

Tuesday, April 29, 2014

“Petrol from seawater “, a Carbon neutral fuel to mitigate climate change !

Recent 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 methane, gasoline, diesel fuel, jet 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- fuel 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 (oxygen) 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 system). 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.

Monday, July 16, 2012

Hydrogen from seawater for Fuelcell

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 witnessed 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 onsite 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 onsite. 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 currently 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 manner. 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.

Monday, June 11, 2012

Innovative desalting technolgy for Chemical industries

Sodium chloride commonly known as ‘ common salt ‘ is a basic raw material for the production of a wide range of chemicals including Caustic soda and Soda ash. The cost of salt has been recently increasing steadily due to wide demand and supply gap all over the world. This in turn has increased the cost of all other chemicals derived from salt and this situation is expected to continue in future. Salt industry has been traditionally using a ‘solar evaporation’, an age old technique from antiquity. The technology involves pumping of seawater on large area of arid land and allowed to evaporate as the concentration of salt increases. The brine then passes on through the various ponds, with the sodium chloride content rising from 2% to 25%. This increasing salinity gives the ponds a distinctive pink color, as algae in strongly saline solutions produce a red pigment called haematochrome. The Red Sea is red for the same reason. The saturated brine is pumped to smaller ponds where nature continues its work of evaporation. Once the volume has been reduced to 10.2% of the original, any further concentration results in the deposition of sodium chloride. From September to February more brine is added until at least 25 mm of salt has settled and it is time for harvesting. The brine remaining (called "bitterns") is a saturated solution of NaCl, with the other salts present at concentrations well below saturation. This is pumped out to sea just before the harvest is gathered, as these ions would contaminate the salt if all the water were evaporated off. For four to six weeks beginning in early March, mechanical harvesters scoop up the crystallized salt and load it on to trucks that shuttle back and forth across the ponds to the washer. In the two washing plants the salt is washed in clean saturated brine, in which the other salts, present as impurities, dissolve. From there hundreds of tones of clean washed salt are discharged daily on to the stacks for storage - up to 10,000 tons per day. During winter no more salt is recovered, but the plant continues its regular work of processing and beggaring the stockpiled salt. But this raw salt has number of impurities such as Calcium, Magnesium and Sulfate ions which are harmful for the production of further chemicals. Though the cost of producing salt is cheaper by solar evaporation, the cost of purifying salt from above impurities and making suitable brine for chemical production is expensive .The cost of salt used in chemical processing industries after transportation and purification increase to whopping $ 200 and above. Many Asian countries such as Japan, South Korea, China, Taiwan and Indonesia are major importers of salt. The salt import by the above importers in Asia pacific region between 2000 and 2009 has increased by 6 million tonnes, equal to 40% or 4.6% per annum.In four years between 2005 and 2009, the price of salt increased by US$25/Mt, equal to 83% or 16% per annum.The average price of imported salt varies between US$40 to $47/Mt. (Ref: Salt partners). Erratic weather patterns, sea level rise, Tsunami, inundation, flooding and unseasonal rains have hampered salt production all over the world. The chemical industries are facing an uncertain future and unpredictable pricing of salt. Prolonged winter in Europe and US and other parts of the world have pushed the demand for salt for de-icing. India is the third largest and cheapest producer of salt in the world with lowest labor cost. But even in India, the prices of salt have gone up recently from Rs.600 to Rs.1000/Mt. An Australian company has developed and patented an innovative technology to solve the above problems. The company uses membrane technology to produce Sodium chloride brine directly from seawater suitable for all chemical products in the downstream. This novel technology separates seawater into salt and drinking water, after all seawater contains about 95% pure water. It can solve the problems of many mining companies in Australia who need Caustic soda as well as water for their processing.

Saturday, May 19, 2012

Sun,sea and chemical industries

How many of us think about the Sun and Sea, when you drink ‘Mineral water’ from that ‘PVC bottle’; or think about the PVC cables that transmit power to your home; or eat meal with a pinch of salt or bicarbonate; or when your municipal water treatment plant use Chlorine to disinfect your drinking water? All these come from sea water energized by sun’s light, day after day, for several decades. Every year 111 billion liters of seawater are evaporated using solar energy to produce 1.1 billion liters of brine. The amount of solar energy required to produce this, is equal to 11 million tons of coal, valued at US$ 1.10 billion. The brine is then crystallized to produce 2 million tones of solar salt, the essential raw material for 18 basic inorganic chemicals, including soda ash. Soda ash and Caustic soda are two fundamentals raw materials to chemical industries, as steel is to the engineering industries. This above statistics applies to one single manufacturer, and there are hundreds of manufacturers around the world. Sun and sea are two great gifts of Nature to mankind. But industries use three great resources namely Sun, seawater and a vast stretch of land often free of cost. Companies convert seawater into salt using sun’s energy, manufacture valuable chemicals, sell them with profits and then dump all toxic wastes on the soil and discharge all the industrial effluents back into the sea, polluting not only the source of their raw materials but also killing thousands of marine species they call ‘sea’ as their home. Governments and EPA (government agencies) turn a blind eye to such pollution and give them clearance year after after year in each country for several decades, because they depend on taxpayer’s money to run their Governments. The manufacturer utilize these natural resources free of cost or at a fraction of a cost and make huge profits to their shareholders and pay tax to the Government, to make sure that Governments don’t interfere with their activities. What is really happening is few rich and powerful are able to exploit the natural resources and enrich themselves with the help of Governments at the cost of earth, water and air, we human beings habitat. This avaricious exploitation of Nature has driven not only human beings but many animals and species to extinction. Basic needs of life such as water and air are polluted, man-made waste are dumped indiscriminately on soil, polluting the earth and ground water. The plastic manufactured using Nature’s sun and sea water, are dumped back on earth as non-biodegradable pollutants. This is how we repay Nature. Human beings have caused an irreversible damage to Nature in the name of science, technology and industrialization at the cost of future generation, while enriching few rich and powerful. The damage is irreversible, because we are forced to continue the same path in order to avert any disruption to our growth story. As long as we value materials over morals and ethics, there is no future and Nature will eventually turn its back with vengeance. We value how much a person is worth financially rather than, what a person can contribute to uplifting human beings and Nature. This is the crux of all problems in the world, including the financial crisis we are currently facing. We created the monster called ‘materialism’ and the same monster is now destroying humanity.

Friday, March 2, 2012

Hydrogen from seawater

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!