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Showing posts with label Coal fired power plants. Show all posts
Showing posts with label Coal fired power plants. Show all posts

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.((http://science1.nasa.gov/media/medialibrary/2013/05/20/thermohaline_assembled) “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 ; http://gereports.com.au/post/25-05-2016/freeze-one-man-instantly-solves-the-world-s-dirtiest-water-problem

Saturday, October 20, 2012

Energy independent America

The recent debate between the presidential nominees in US election has revealed their respective positions on their policies for an energy independent America. Each of them have articulated how they will increase the oil and gas production to make America energy independent, which will also incidentally create number of jobs in an ailing economy. Each one of them will be spending a billion dollar first, in driving their messages to the voting public. Once elected, they will explore oil and gas aggressively that will make America energy independent. They will also explore solar and wind energy potentials simultaneously to bridge any shortfall. Their policies seem to be unconcerned with global warming and its impact due to emission of GHG but, rather aggressive in making America an energy independent by generating an unabated emission of GHG in the future. Does it mean an ‘energy independent America’ will spell a doom to the world including US? The best option for America to become energy independent will be to focus on energy efficiency of existing technologies and systems, combining renewable-fossil fuel energy mix, base load renewable power and storage technologies, substituting Gasoline with Hydrogen using renewable energy sources. The future investment should be based on sustainable renewable energy sources rather than fossil fuel. But current financial and unemployment situation in US will force the new president to increase the conventional and unconventional oil and gas production rather than renewable energy production, which will be initially expensive with long pay pack periods but will eventually meet the energy requirement in a sustainable way. The net result of their current policies will be an enhanced emission of GHG and acceleration of global warming. But the energy projections in the U.S. Energy Information Administration’s (EIA’s) Annual Energy Outlook 2012 (AEO2012) projects a reduced GHG emission. According to Annual Energy Outlook 2012 report: “The projections in the U.S. Energy Information Administration’s (EIA’s) Annual Energy Outlook 2012 (AEO2012) focus on the factors that shape the U.S. energy system over the long term. Under the assumption that current laws and regulations remain unchanged throughout the projections, the AEO2012 Reference case provides the basis for examination and discussion of energy production, consumption, technology, and market trends and the direction they may take in the future. It also serves as a starting point for analysis of potential changes in energy policies. But AEO2012 is not limited to the Reference case. It also includes 29 alternative cases, which explore important areas of uncertainty for markets, technologies, and policies in the U.S. energy economy. Many of the implications of the alternative cases are discussed in the “Issues in focus” section of this report. Key results highlighted in AEO2012 include continued modest growth in demand for energy over the next 25 years and increased domestic crude oil and natural gas production, largely driven by rising production from tight oil and shale resources. As a result, U.S. reliance on imported oil is reduced; domestic production of natural gas exceeds consumption, allowing for net exports; a growing share of U.S. electric power generation is met with natural gas and renewable; and energy-related carbon dioxide emissions remain below their 2005 level from 2010 to 2035, even in the absence of new Federal policies designed to mitigate greenhouse gas (GHG) emissions. The rate of growth in energy use slows over the projection period, reflecting moderate population growth, an extended economic recovery, and increasing energy efficiency in end-use applications. Overall U.S. energy consumption grows at an average annual rate of 0.3 percent from 2010 through 2035 in the AEO2012 Reference case. The U.S. does not return to the levels of energy demand growth experienced in the 20 years prior to the 2008- 2009 recession, because of more moderate projected economic growth and population growth, coupled with increasing levels of energy efficiency. For some end uses, current Federal and State energy requirements and incentives play a continuing role in requiring more efficient technologies. Projected energy demand for transportation grows at an annual rate of 0.1 percent from 2010 through 2035 in the Reference case, and electricity demand grows by 0.7 percent per year, primarily as a result of rising energy consumption in the buildings sector. Energy consumption per capita declines by an average of 0.6 percent per year from 2010 to 2035 (Figure 1). The energy intensity of the U.S. economy, measured as primary energy use in British thermal units (Btu) per dollar of gross domestic product (GDP) in 2005 dollars, declines by an average of 2.1 percent per year from 2010 to 2035. New Federal and State policies could lead to further reductions in energy consumption. The potential impact of technology change and the proposed vehicle fuel efficiency standards on energy consumption are discussed in “Issues in focus.” Domestic crude oil production increases Domestic crude oil production has increased over the past few years, reversing a decline that began in 1986. U.S. crude oil production increased from 5.0 million barrels per day in 2008 to 5.5 million barrels per day in 2010. Over the next 10 years, continued development of tight oil, in combination with the ongoing development of offshore resources in the Gulf of Mexico, pushes domestic crude oil production higher. Because the technology advances that have provided for recent increases in supply are still in the early stages of development, future U.S. crude oil production could vary significantly, depending on the outcomes of key uncertainties related to well placement and recovery rates. Those uncertainties are highlighted in this Annual Energy Outlook’s “Issues in focus” section, which includes an article examining impacts of uncertainty about current estimates of the crude oil and natural gas resources. The AEO2012 projections considering variations in these variables show total U.S. crude oil production in 2035 ranging from 5.5 million barrels per day to 7.8 million barrels per day, and projections for U.S. tight oil production from eight selected plays in 2035 ranging from 0.7 million barrels per day to 2.8 million barrels per day (Figure 2). With modest economic growth, increased efficiency, growing domestic production, and continued adoption of nonpetroleum liquids, net imports of petroleum and other liquids make up a smaller share of total U.S. energy consumption U.S. dependence on imported petroleum and other liquids declines in the AEO2012 Reference case, primarily as a result of rising energy prices; growth in domestic crude oil production to more than 1 million barrels per day above 2010 levels in 2020; an increase of 1.2 million barrels per day crude oil equivalent from 2010 to 2035 in the use of biofuels, much of which is produced domestically; and slower growth of energy consumption in the transportation sector as a result of existing corporate average fuel economy standards. Proposed fuel economy standards covering vehicle model years (MY) 2017 through 2025 that are not included in the Reference case would further reduce projected need for liquid imports. Although U.S. consumption of petroleum and other liquid fuels continues to grow through 2035 in the Reference case, the reliance on imports of petroleum and other liquids as a share of total consumption decline. Total U.S. consumption of petroleum and other liquids, including both fossil fuels and biofuels, rises from 19.2 million barrels per day in 2010 to 19.9 million barrels per day in 2035 in the Reference case. The net import share of domestic consumption, which reached 60 percent in 2005 and 2006 before falling to 49 percent in 2010, continues falling in the Reference case to 36 percent in 2035 (Figure 3). Proposed light-duty vehicles (LDV) fuel economy standards covering vehicle MY 2017 through 2025, which are not included in the Reference case, could further reduce demand for petroleum and other liquids and the need for imports, and increased supplies from U.S. tight oil deposits could also significantly decrease the need for imports, as discussed in more detail in “Issues in focus.” Natural gas production increases throughout the projection period, allowing the United States to transition from a net importer to a net exporter of natural gas Much of the growth in natural gas production in the AEO2012 Reference case results from the application of recent technological advances and continued drilling in shale plays with high concentrations of natural gas liquids and crude oil, which have a higher value than dry natural gas in energy equivalent terms. Shale gas production increases in the Reference case from 5.0 trillion cubic feet per year in 2010 (23 percent of total U.S. dry gas production) to 13.6 trillion cubic feet per year in 2035 (49 percent of total U.S. dry gas production). As with tight oil, when looking forward to 2035, there are unresolved uncertainties surrounding the technological advances that have made shale gas production a reality. The potential impact of those uncertainties results in a range of outcomes for U.S. shale gas production from 9.7 to 20.5 trillion cubic feet per year when looking forward to 2035. As a result of the projected growth in production, U.S. natural gas production exceeds consumption early in the next decade in the Reference case (Figure 4). The outlook reflects increased use of liquefied natural gas in markets outside North America, strong growth in domestic natural gas production, reduced pipeline imports and increased pipeline exports, and relatively low natural gas prices in the United States. Power generation from renewable and natural gas continues to increase In the Reference case, the natural gas share of electric power generation increases from 24 percent in 2010 to 28 percent in 2035, while the renewable share grows from 10 percent to 15 percent. In contrast, the share of generation from coal-fired power plants declines. The historical reliance on coal-fired power plants in the U.S. electric power sector has begun to wane in recent years. Over the next 25 years, the share of electricity generation from coal falls to 38 percent, well below the 48-percent share seen as recently as 2008, due to slow growth in electricity demand, increased competition from natural gas and renewable generation, and the need to comply with new environmental regulations. Although the current trend toward increased use of natural gas and renewable appears fairly robust, there is uncertainty about the factors influencing the fuel mix for electricity generation. AEO2012 includes several cases examining the impacts on coal-fired plant generation and retirements resulting from different paths for electricity demand growth, coal and natural gas prices, and compliance with upcoming environmental rules. While the Reference case projects 49 gigawatts of coal-fired generation retirements over the 2011 to 2035 period, nearly all of which occurs over the next 10 years, the range for cumulative retirements of coal-fired power plants over the projection period varies considerably across the alternative cases (Figure 5), from a low of 34 gigawatts (11 percent of the coal-fired generator fleet) to a high of 70 gigawatts (22 percent of the fleet). The high end of the range is based on much lower natural gas prices than those assumed in the Reference case; the lower end of the range is based on stronger economic growth, leading to stronger growth in electricity demand and higher natural gas prices. Other alternative cases, with varying assumptions about coal prices and the length of the period over which environmental compliance costs will be recovered, but no assumption of new policies to limit GHG emissions from existing plants, also yield cumulative retirements within a range of 34 to 70 gigawatts. Retirements of coal-fired capacity exceed the high end of the range (70 gigawatts) when a significant GHG policy is assumed (for further description of the cases and results, see “Issues in focus”). Total energy-related emissions of carbon dioxide in the United States remain below their 2005 level through 2035 Energy-related carbon dioxide (CO2) emissions grow slowly in the AEO2012 Reference case, due to a combination of modest economic growth, growing use of renewable technologies and fuels, efficiency improvements, slow growth in electricity demand, and increased use of natural gas, which is less carbon-intensive than other fossil fuels. In the Reference case, which assumes no explicit Federal regulations to limit GHG emissions beyond vehicle GHG standards (although State programs and renewable portfolio standards are included), energy-related CO2 emissions grow by just over 2 percent from 2010 to 2035, to a total of 5,758 million metric tons in 2035 (Figure 6). CO2 emissions in 2020 in the Reference case are more than 9 percent below the 2005 level of 5,996 million metric tons, and they still are below the 2005 level at the end of the projection period. Emissions per capita fall by an average of 1.0 percent per year from 2005 to 2035. Projections for CO2 emissions are sensitive to such economic and regulatory factors due to the pervasiveness of fossil fuel use in the economy. These linkages result in a range of potential GHG emissions scenarios. In the AEO2012 Low and High Economic Growth cases, projections for total primary energy consumption in 2035 are, respectively, 100.0 quadrillion Btu (6.4 percent below the Reference case) and 114.4 quadrillion Btu (7.0 percent above the Reference case), and projections for energy-related CO2 emissions in 2035 are 5,356 million metric tons (7.0 percent below the Reference case) and 6,117 million metric tons (6.2 percent above the Reference case)”. (Ref:U.S. Energy Information Administration).

Tuesday, March 13, 2012

Coal-water-slurry- a new source of Hydrogen?

Dirty coal is still a popular choice for power generation around the world, irrespective of the status of the country, whether industrially advanced or backward. The abundant availability and cheap cost, makes coal more attractive from investor’s point of view; they care less for the environment, while Governments turn a blind eye to all the emissions and pollutions. It is a question of survival for millions of people who work in coal mines and industries. It is one of the toughest challenges many Governments are facing. Take for example India; about 65% of power generation still comes from coal. The import of coal increases year after year and there is no immediate solution in sight. Indian coal is a low grade coal with very high ash content. Each coal-fired power plant generates huge amount of fly ash and they stockpile them; supposed to be used in the production of Portland cement. It is a big business. China and Indonesia too uses coal as a major fuel for power generation. But they have come out with an innovative and pragmatic method of using coal. They use coal-water-slurry (CWS), a finely pulverized high grade coal (calorific value 5100-6100Kcal/kg) in water. They use some chemical additives that make the slurry a homogeneous fluid, similar to a Hydrocarbon such as Heavy fuel oil (HFO).The advantage with CWS is it can be easily pumped and injected into a furnace or boiler using ceramic nozzles, obviously to avoid erosion due the abrasive nature of coal, just like firing diesel or heavy oil. According to the literature, 1.8 -2.2 tons of CWS is equivalent to 1 ton of Heavy fuel oil (HFO) and it costs the same. It cost only US$ 62 million to retrofit an existing coal fired power plant with CWS system and the yearly savings are estimated at US$ 41 mil per year, an attractive rerun on investment. The beautiful aspect of this method is it generates Hydrogen rich Syngas according to the following chemical reaction. 2C + O2+2 H2O -------- 2H2+2 CO2, when the mixture is subject to gasification instead of mere combustion. The combustion efficiency is about 96-99% and the boiler efficiency of more than 90%. It generates less Sulfur dioxide and Nitrogen oxide emissions and good for the environment compared to conventional coal- fired power plants. It is a good technology that needs the attention of Governments especially India, China and Indonesisa.Even coal rich countries like US, Australia should focus on this technology apart from their persuasion such as carbon sequestration. In fact, this will open up new avenues for India and China to switch over to Hydrogen economy, without making substantial investments. The coal-water-slurry fluid has a property similar to a Hydrocarbon as shown below. Density 65-70% ,Viscosity 1000Cp, Size d< 50 microns, Ash content <7, Sulfur<0.5%. It is easier to handle a liquid than solid coal. Pulverised coal is pneumatically conveyed and fired in rotary cement kilns for so many years. There is nothing new about it. Similarly coal water slurry can be a game changer for the power industry if it is combined with Gasification and combined cycle. It will lead into Hydrogen based power generation industries using Fuel cell such as Molten Carbonate Fuel cell (MCFC). I believe there is a clear opportunity for the Governments and private industries to seriously look into CWS technology which I believe, is a ‘precursor’ for Hydrogen economy of the future.