This review article focuses on corrosion and erosion of coal combustion chamber.
Coal fire power plant
Fluidized bed combustion chamber
Mechanism of fluidized bed combustion chamber
Effect of corrosion and erosion on fluidized bed combustion chamber
Preventive measure solutions against hot corrosion and erosion problem
Different types of systems for coal power plant installation.
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K E Y W O R D S
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Hot corrosion , erosion , chlorine , Chemical vapor deposition , Physical vapor deposition , super heater , water wall , Boiler , Thermal spraying , Nanostructured
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The problems create by the emission and corrosion can be solve by changing the material, Spraying & coating with use of different types material, altering the territory or by separating the component surface from the atmosphere. The reason behind this paper is to present a literature review of current explanations on parameters which effect on the erosion-corrosion of combustion bed coil like coal properties, air flow velocity, tube material, nozzle diameter, thickness and pitch of bed coil, size and shape of the boiler tubes etc. Furthermore, several different hypotheses based on experimental studies, analytical studies, and numerical studies have been put forward to describe the Optimization of coal combustion process.
1. INTRODUCTION
Now a days in all over the world majority of electricity is generated in coal-fired thermal plants, in which the coal is used for burned to boil water and the steam produced is expanded through a turbine, which turns a generator [2]. And at the same time low pressure steam exit at the end of the turbine and it is condensed by the condenser and returned to the boiler.
Erosion and corrosion in coal combustion chamber is a major problem faced by coal fire power plant. Coal is a very complex and relatively pollutant fuel that contains huge amount of S02 and substantial fraction of noncombustible mineral constituents, commonly called ash And majority of coal used in coal power stations has
Tens of business closed up, which directly affected a large number of households. The coal mining operations companies also left environmental contaminants in the environment. Pollutions from coal mining have a direct effect on water, land air. Some of the pollutants contaminate ground water, surface water and impact on other land-uses. Besides the slope failure and explosion, environmental impact from coal mining causes erosion; leachates production, which seeping into ground water, and dust pollution. Heavy metals compound like lead, cadmium and arsenic dominates coal mining sites (Bhuiyan, Parvez, Islam, & Dampare, 2010). These metals are toxic to plant and animal. Some absorb some of these dissolved metals and introduce them into the food circle. When rainwater mixes with coal waste, the runoffs becomes acidic, which reduce PH of surface waters. (Komitas, 2001) Population inhaling coal dust suffers black lung disease and other complication like lung cancer, and heart failure (Finkelman & Orem, 2002). Coal mining in uranium mines is another source of radioactive exposure. Another environmental impact from coal mined lands includes emission of greenhouse gasses. Future land redevelopment in grand Cache, must deal with this issues before development could take
Clean coal technology usually addresses atmospheric problems resulting from burning coal. Historically, the primary focus was on sulfur dioxide and particulates, since it is the most important gas in the causation of acid rain. More recent focus has been on carbon dioxide (due to its impact on global warming) as well as other pollutants. Concerns exist regarding the economic viability of these technologies and the timeframe of delivery, potentially high hidden economic costs in terms of social and environmental damage, and the costs and viability of disposing of removed carbon and other toxic matter. More, the byproducts of coal power production range from fly ash sludge ponds full of mercury, arsenic, and sulfur in unlined ponds that can leak into the water supply.
The igneous intrusions in the Raton Basin provide a high temperature and pressure environment promotes an increase in generation of gas (Jian and Cheng, 2014). No evidence suggests that the different intrusions within the coal were at different temperatures (Rooper et al., 2006). It has been suggested that the heat from the dikes enhance adsorption and porosity in coals and also increase the trap capacities of gas storage (Jian and Cheng, 2014). Igneous intrusions create safety problems in the mines underground and the gas created could result in the projection and rapid release of gases (Jian and Cheng, 2014).
For the 300 MW steam plant currently under analysis, steam is required at 723 K (450 0C), 10.34 MPa and a mass flow rate of 330 kg/s. The steam turbine extracts 312.5 MW of power at 84 percent adiabatic efficiency. With the generator loss at 4 percent, the electrical output is 300 MWe. A mechanical pump is used to pump the water into the heat exchanger where it absorbs the heat from the helium turbine exhaust before entering the steam turbine. Design point specifications are given in Table 4-1.
Generating power with gas (as an alternative to coal) and increasing the use of renewable energy sources also seem like very suitable options [9]. Additionally, power generation with the use of wind and tidal energy proves a very convenient alternative to nuclear power generation in London and the UK in general. These sources can deliver twice the amount of electricity as new-age nuclear reactors and would require less time to be implemented, thus the convenience [12].
Coal ash is known to contain a number of different toxic metals, the exact content dependent upon the coal it is formed from. Containing this potential pollution hazard is an expensive problem, as approximately 75% of all ash generated is stored in landfills. In these sites, rainwater can leach out toxic metals including mercury, arsenic, cadmium, chromium, molybdenum, lead and selenium. As over 500 million tons of ash are produced each year, there’s an increasing environmental health hazard to the surrounding water systems of these landfills. Pollution can spread to municipal water systems and potentially poison humans. As such, figuring out a better solution to deal with the unused coal ash is of significant importance. Current uses of coal ash primarily include the formation of concrete due the pozzolanic properties of coal
“Power plants use flue gas desulfurization equipment, also known as scrubbers, to clean sulfur from the smoke before it leaves their smokestacks. In addition, industry and the U.S. government have cooperated to develop technologies that can remove impurities from coal or that can make coal more energy-efficient so less needs to be burned.” (Coal).
Coal is the dirtiest of all fossil fuels. When burned, it produces emissions that contribute to global warming, create acid rain and pollute water. With all of the talk surrounding nuclear energy, hydropower and biofuels, you might be forgiven for thinking that grimy coal is finally on its way out. On the other hand, coal is no sooty remnant of the Industrial Revolution - it generates half of the electricity in the United States and will likely continue to do so as long as it's cheap and plentiful . Clean coal technology seeks to reduce harsh environmental effects by using multiple technologies to clean. Coal is a fossil fuel composed primarily of carbons and hydrocarbons. Its ingredients help make plastics, tar and fertilizers. A coal derivative, a solidified carbon called coke, melts iron ore and reduces it to create steel. But most coal - 92 percent of the U.S. supply - goes into power production .Electric companies and businesses with power plants burn coal to make the steam that turns turbines and generates electricity. When coal burns, it releases carbon dioxide and other emissions in flue gas, the billowing clouds you see pouring out of smoke stacks. Some clean coal technologies purify the coal before it burns. One type of coal preparation, coal washing, removes unwanted minerals by mixing crushed coal with a liquid and allowing the impurities to separate and settle. Other systems control the coal burn to minimize emissions of sulfur dioxide, nitrogen oxides and
Things like mining too far into a wall that connects to an older mine, thus increasing the danger of a collapse, is common. Other practices include shoddy dams that contain the slurry, a mixture of water and fine particles of coal, which do not always meet structural regulations that can and have broken and flood nearby communities (Light and Light, 2006). There are other environmental issues that are associated with coal mining. Acid mine drainage is the result of sulfide minerals being exposed to oxygen. This produces sulfuric acid and can dissolve heavy metals from the waste rock, making it bioavailable. Without proper treatment, this will poison the water systems near that mine and will seep into the streams, creeks, and even ground and well water. The water turns orange and is impossible for anything to live off of the water or in it (Kirsch, 2014). Another issue of coal mining is airborne coal dust, which can result in Black Lung disease. This is caused by inhaling too much coal dust and is common in miners, but with surface mining becoming more prevalent, more coal dust is being released into the air and drifting down to the communities. More children and elderly people are having respiratory problems that many believe are because of
Nowadays, coal is still one of the greatest used energy to generate power in so many countries. Using coal in electricity generation is 93% in South African, 87% in Poland, 79% in China, 78% in Australia, 45% in USA, 41% in Germany, 58% in Israel etc. (Coal & Electricity) From the data above, even the developed countries use coal to generate power as the main source. In many developed countries, energy generation is still based on coal as a long-term source. In recent years, although there is an increasing number of equipment using gas and wind to generate the power, it is still lower than the proportion of coal-fired power generation. The reason why most countries choose coal as a main source to generate electricity, is that there are many advantages in using coal to generate electricity. First of all, coal is the
As we go throughout life, we use various kinds of energy sources for our needs. Whether it be from solar energy to wind energy, there is a multitude of sources that allow us to do the things we do each and every day. Throughout the world, however, coal and nuclear power have risen to the
Coal’s reputation has become as black as coal itself, but without it the quality of life that hundreds of millions of people enjoy today would not be possible. Coal has been used in many ways throughout history and it will continue to be a vital resource in supplying the energy needed to fuel an energy hungry world. Research cited throughout this paper suggests that coal is an energy source for the future because it is stable and reliable with abundant reserves, it is the most affordable and efficient fuel source used to produce power, and because of new clean coal technologies, coal can be burned with minimal to no damage to the environment.
Many species of animals are also being killed from coal pollution. Coal produces acid rain, Acid rain is a rainfall made acidic. As acid rain hits the earth it spreads to many different environments and reaching ground water thus making them very dangerous to those animals. As acid rain mixes with water it causes many aquatic species to die. Acid rain caused 75 percent of acidic lakes and 50 percent of acidic streams.
In this study, information on the gasification behaviour of two Victorian brown coals, Yallourn (YL) and Morwell (MW) coal, is reported, including the release of alkali, sulphur, and chlorine spieces, carbon conversion, and gas quality during CO2 gasification. The relation between 100% carbon conversion and residence time was investigated by regasifying the chars after every run of 5-6s residence time. This study generates fundamental information that will be useful for the design of commercial entrained-flow gasifiers using Victorian brown coals.
A coal power station turns the chemical energy in coal into electrical energy that can be used in homes and businesses.