Wednesday, June 29, 2016

Carbon is to return to Carbon

Carbon emission is a matter of great concern to all the countries around the world due to the global warming and climate change. After the Paris talks many countries are genuinely trying to reduce their emissions either by switching over to renewable energy or cutting down their emissions by reducing their Carbon footprint. In their desperate measure to reduce Carbon emissions some countries like Canada are trying to accelerate carbon emission reduction by promoting innovation technologies with millions of dollars of grant money. Recent fires in the state of Alberta, rich in oil sand deposits have opened the eyes of the world to witness how a disaster can unfold so quickly and thousands of people to be evacuated in a short notice. Many fled their homes leaving behind their valuables and memories. It was one of the worst fire disasters in recent memory. Canada especially the state of Alberta is now all the more determined to avert such incidents in the future but also equally determined to reduce their Carbon emissions. The fire is due to dry conditions due to global warming and accelerated by oil sands. It is a perfect recipe for a disaster. Many countries have switched over from coal to natural gas as a cleaner fuel to reduce their Carbon emission. Natural gas emits less CO2 compared to coal. But does it help combat global warming? One has to compare the two different fuels and their combustion by the following reactions: C + O2 ----> CO2 and CH4 + 2O2 -------> CO2 + 2H2O Combustion of coal requires less Oxygen (air) when compared to combustion of natural gas which requires twice the volume of Oxygen (air). Coal combustion emits oxides of Nitrogen and Sulphur apart from CO2 and a minor quantity of water vapour and particulate matters. Combustion of natural gas releases twice the volume of water vapour apart from oxides of Nitrogen and sulphur. Recent findings by NASA confirms that water vapour is the major greenhouse gas apart from CO2 that is responsible for warming globe and the climate change. Therefore, natural gas does not help combating global warming and climate change. The following excerpts from NASA highlights this fact: Water Vapour Confirmed as Major Player in Climate Change Credit: NASA The distribution of atmospheric water vapour, a significant greenhouse gas, varies across the globe. During the summer and fall of 2005, this visualization shows that most vapour collects at tropical latitudes, particularly over south Asia, where monsoon thunderstorms swept the gas some 2 miles above the land. Water vapour is known to be Earth’s most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated more precisely than ever the heat-trapping effect of water in the air, validating the role of the gas as a critical component of climate change. Andrew Dressler and colleagues from Texas A&M University in College Station confirmed that the heat-amplifying effect of water vapour is potent enough to double the climate warming caused by increased levels of carbon dioxide in the atmosphere. With new observations, the scientists confirmed experimentally what existing climate models had anticipated theoretically. The research team used novel data from the Atmospheric Infrared Sounder (AIRS) on NASA’s Aqua satellite to measure precisely the humidity throughout the lowest 10 miles of the atmosphere. That information was combined with global observations of shifts in temperature, allowing researchers to build a comprehensive picture of the interplay between water vapour, carbon dioxide, and other atmosphere-warming gases. The NASA-funded research was published recently in the American Geophysical Union's Geophysical Research Letters. AIRS is the first instrument to distinguish differences in the amount of water vapour at all altitudes within the troposphere. Using data from AIRS, the team observed how atmospheric water vapour reacted to shifts in surface temperatures between 2003 and 2008. By determining how humidity changed with surface temperature, the team could compute the average global strength of the water vapour feedback. “This new data set shows that as surface temperature increases, so does atmospheric humidity,” Dressler said. “Dumping greenhouse gases into the atmosphere makes the atmosphere more humid. And since water vapour is itself a greenhouse gas, the increase in humidity amplifies the warming from carbon dioxide." Specifically, the team found that if Earth warms 1.8 degrees Fahrenheit, the associated increase in water vapour will trap an extra 2 Watts of energy per square meter (about 11
square feet) "That number may not sound like much, but add up all of that energy over the entire Earth surface and you find that water vapour is trapping a lot of energy," Dressler said. "We now think the water vapour feedback is extraordinarily strong, capable of doubling the warming due to carbon dioxide alone." Because the new precise observations agree with existing assessments of water vapour’s impact, researchers are more confident than ever in model predictions that Earth's leading greenhouse gas will contribute to a temperature rise of a few degrees by the end of the century. The amount water vapour released by burning natural gas is twice the volume of natural gas burnt. A plant using 10,000 m3/day natural gas can release 20,000m3/day water vapour that can be recovered. In fact, if the Gulf countries can recover water from exhaust of their gas fired power plants they may not require any water by desalination of seawater at all. Current consumption of natural gas world-wide exceeds 3.5 trillion cubic meters which roughly translates to 7 trillion cubic meters of water vapour into the atmosphere. Such a large volume has a potential to change our climate system.What goes up as water vapour has to condense into water and come down.It has a potential to flood many parts of the world and we are already witnessing flash flooding more frequently.The economic loss by such natural disasters may run into several hundreds of billion dollars in future.It is absoluetly critical that human induced emissions are curtailed with great urgency. It is interesting to examine how the state of Alberta is trying to reduce their carbon emissions by promoting innovative technologies. Majority of the proposals are supposed to convert CO2 emissions into “a useful product” so that the emission can be curtailed or reduced. A quick glance on the list of the proposals they have funded so far indicates they will convert CO2 into an industrial chemical such as Methanol or a Fertilizer such as Urea or alkaline chemicals such as bicarbonates and calcium carbonates etc. Can they really solve the problem of carbon emissions by turning them into useful products? The answer is most likely no. It will help capture CO2 at Alberta but it will be released somewhere else where the end products are used. It will simply shift the problems of Carbon emission from Alberta into some other region of the world. For example, Urea synthesised from captured CO2 will again be released into the atmosphere when Urea is used by farmers. An enzyme in the soil will release the CO2 from Urea into the atmosphere. The only real solution is to convert captured CO2 back into a fuel such as SNG (synthetic natural gas) so that it can be recycled into the power plant. By this way the CO2 emission will be converted into solid Carbon. One need not bury CO2 under the ground or emit it into the atmosphere but constantly recycle into SNG so that power plant can generate power continuously without emitting any greenhouse emissions. To do this we need Hydrogen. At present Hydrogen is produced commercially from natural gas but with carbon emission. Other methods of producing Hydrogen without carbon emissions are expensive. But Hydrogen can be generated from natural gas without Carbon emission and it can be used to convert captured CO2 from power plants into SNG. In other words, two greenhouse gases namely CO2 and methane (CH4) will be reacted to generate commercially valuable Carbon nanotube as a main product as shown below. This high temperature reaction can generate superheated steam that can generate power while a valuable solid Carbon is regenerated. Such a process is still in a developmental stage but has a potential to become a commercial reality in the near future. CH4 + CO2 ------------> 2C + 2 H2O In fact, the carbon emission is converted back into a solid Carbon. The Carbon is to return to Carbon to avoid GHG emission (CO2, N2O, NO2 and H2O) that is changing our climate.

Saturday, April 23, 2016

Parched land and thirsty farmers surrounded by ocean of water

The climate is changing and the impact of such a change is felt almost in every sphere of life around the world especially in countries like India. ” Erratic monsoon rain patterns have left crops parched, jeopardizing India’s nearly $370 billion agricultural sector and hundreds of millions of jobs. Drought conditions are crippling vast swaths of India’s farmland as the country faces its driest monsoon since 2009. With more than 60 percent of India’s agriculture reliant on monsoon rains, farmers are highly vulnerable to changes in rainfall patterns and rising global temperatures, the Indian Council for Research on International Economic Relations found in a report” according to the International Business Times. The situation in Australia is no different from India, both surrounded by ocean of water yet no water to irrigate or even to drink. Many scientific studies have clearly highlighted the close relationship between warming earth, increasing salinity of seawater and the climate change. But new coal fired power plants and seawater desalination plants are set up almost every year in these countries. Both greenhouse gas and the increasing salinity of seawater will only contribute to intensify further warming of the earth. There is some awareness about the global warming by GHG but there is no awareness about the increasing salinity of seawater. One of the largest desalination plant set up in the state of Victoria in Australia is idle for so many years yet unable to supply water to struggling farmers in the country Victoria. In a way it is a blessing in disguise because it would have otherwise discharged billions of cubic meters of RO concentrate with toxic chemicals into bass strait. California law requires that any “new or expanded coastal ... industrial installation using seawater” must utilize “the best available site, design, technology and mitigation measures feasible ... to minimize the intake and mortality of all forms of marine life.” (California Water Code section 13142.5(b) The following excerpts from NASA highlights the close relationship between Ocean salinity and changing climate and rainfall.(( “SALINITY, OCEAN CIRCULATION & CLIMATE Surface winds drive currents in the upper ocean. Deep below the surface, however, ocean circulation is primarily driven by changes in seawater density, which is determined by salinity and temperature. In some regions such as the North Atlantic near Greenland, cooled high-salinity surface waters can become dense enough to sink to great depths. The 'Global Conveyor Belt' visualization (below) shows a simplified model of how this type of circulation would work as an interconnected system. The ocean stores more heat in the uppermost three (3) meters than the entire atmosphere. Thus density-controlled circulation is key to transporting heat in the ocean and maintaining Earth's climate. Excess heat associated with the increase in global temperature during the last century is being absorbed and moved by the ocean. In addition, studies suggest that seawater is becoming fresher in high latitudes and tropical areas dominated by rain, while in sub-tropical high evaporation regions, waters are getting saltier. Such changes in the water cycle could significantly impact not only ocean circulation but also the climate in which we live. 'The Global Conveyer Belt' represents in a simple way how currents move beneath the wind-driven upper ocean. This movie begins by focusing on the North Atlantic east of Greenland, where cold surface waters get saltier due to evaporation and/or sea ice formation. In this region, surface waters can become dense enough to sink to the ocean depths. This pumping of surface water into the deep ocean forces the deep water to move horizontally until it can find areas where it can rise back to the surface. This very large, slow current -- estimated to be on the order of 1000 years to complete a full circuit -- is called the thermohaline circulation because it is caused by temperature (thermo) and salinity (haline) variations. Credit: NASA/GSFC Launched June 10, 2011, aboard the Argentine spacecraft Aquarius/Satélite de Aplicaciones Científicas (SAC)-D, Aquarius is NASA’s first satellite instrument specifically built to study the salt content of ocean surface waters. Salinity variations, one of the main drivers of ocean circulation, are closely connected with the cycling of freshwater around the planet and provide scientists with valuable information on how the changing global climate is altering global rainfall patterns. The salinity sensor detects the microwave emissivity of the top 1 to 2 centimetres (about an inch) of ocean water – a physical property that varies depending on temperature and saltiness. The instrument collects data in 386 kilometre-wide (240-mile) swaths in an orbit designed to obtain a complete survey of global salinity of ice-free oceans every seven days.” According to a new report on desalination in California Desalination is the removal of salts from saline water (brackish or seawater) using distillation or membrane separation technologies in most cases Current desalination technologies produce a toxic concentrated brine discharge that contains all the salts and dissolved solids along with process chemicals. Putting the brine “cocktail” back into the ocean damages the marine environment and runs counter to the environmental goals of the state. The brine creates extensive damage in the ocean in areas sometimes called dead zones. The damage affects the environment, the economy, and the quality of life of the neighbouring areas on land and off shore. Desalination is receiving increased attention as a means for addressing the water supply challenges of California. The state’s growing population, much of which is located in semi-arid regions, periodic droughts, and other water demands create pressure on existing water supplies and strong incentives to find new ones. (California Desalination Planning Handbook, Dept. of Water Resources, 2008, p.1) With the state’s 3,427 miles of Pacific coastline, (CA Water Plan, 2009, Volume 2, Strategic Resource Management, Chapter 26, Water‐Dependent Recreation. 26‐5) desalination of sea water is a reasonable response to the need for a reliable supply of more potable water—if it can be done without environmental damage. New desalination technologies exist that produce no brine (and no concentrated brine cocktails). They should be chosen as best available technology (BAT) in the future. The California report says: “Consequences of all aspects combined
The brine cocktail damages many life forms - plant and animal; adults, larvae, and eggs. It kills some outright. It prevents reproduction for some. It impedes growth and thriving for some. And the damage can happen at only slightly elevated levels of concentration. The hypoxic brine and chemical mixture is like plastic wrap suffocating the organisms living on the sea floor. Fish can swim away to better water conditions. Plants, eggs, larvae, and stationery or slow moving animals like coral, clams, and crabs cannot. In a comprehensive review of published studies about the impacts of desalination plant discharges, David A Roberts and team reviewed 8 field studies and 10 laboratory experiments that examined a range of salinities and a variety of organisms from waters in the US and Spain. They concluded that experiments in the field and laboratory clearly demonstrate the potential for acute and chronic toxicity, and small-scale alterations to community structure following exposures to environmentally realistic concentrations of desalination brines. The observed effects of the tests in the study mentioned above included fertilization, germination, growth and development, and mortality on seven organisms. The study was focused on the effects of several brine concentrations and used brine prepared in the laboratory or taken from an RO plant discharge. It did not look at the effects of the chemical additives or exposure over long terms. Even so, it found effects over limited time periods on several species at some state of development and varying concentrations. For many marine invertebrates the larvae are especially susceptible to brine concentrations.” Both energy and water are increasing in demand as the population grows and it is critical to choose the right type of technology to sustain such a growth. Wrong choices made due to popularity or quick fixes will lead to long term consequences. Desalination with zero liquid discharge should be a mandatory so that large multinational companies will at least spend some funds on R&D towards achieving such a goal. Otherwise it will continue to be a “business as usual”. The author recently won a water challenge from GE -Statoil and you can view it in the following link ;