Coal is a combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, with smaller quantities of sulfur, oxygen and nitrogen..continue..
A coal-fired power station produces electricity, usually for public consumption, by burning coal to boil water, producing steam which drives a steam turbine which turns an electrical generator. Power station operators play a key part in keeping the boilers fired equally and steam adjusted correctly to burn the coal in the most efficient way possible..continue..
The use of electricity has been an essential part of the U.S. economy since the turn of the century. Coal power, an established electricity source that provides vast quantities of inexpensive, reliable power has become more important as supplies of oil and natural gas diminish. In 1995, Coal burning produced about 55% of the electricity generated in the U.S. In addition, know coal reserves are expected to last for centuries at current rates of usage..continue..
PROCESS AND TECHNOLOGY STATUS – Some 42% of the world’s electricity production is based on coal combustion. The world’s coal-fired capacity is 1440 GWe out of a global capacity of 4509 GWe (2007). In China, around 71% of the total installed capacity (502 GWe out of 706 GWe, 2007) is based on coal-fired power plants. Currently, supercritical pulverised coal (SCPC) power - a mature technology - is the dominant option for new coal-fired power plants. In a SCPC power plant, pulverised coal combustion generates heat that is transferred to the boiler to generate supercritical steam. The steam is then used to drive a steam turbine and an electricity generator. Pulverised coal-fired power plants produce a considerable amount of airborne emissions...continue..
Power stations work by harnessing a suitable raw energy source and turning it into electrical energy that can be sent to homes and industry. There are several steps involved in the creation of electricity. The electricity used in homes and businesses is mostly generated at power stations by burning coal, gas or other fuels (e.g. bagasse) in a large furnace that boils water and turns it into steam. This steam is forced at high temperature and pressure through a turbine, which is like a giant fan. The steam forces the blades of the turbine to spin (turning the heat energy from burning fuel into kinetic energy, or movement). The turbine is connected to a generator - a coil of wire surrounded by large magnets which create a strong magnetic field. The turbine spins the coil of wire in the magnetic field, producing electricity. The steam is then cooled, condensed back into water and returned to the boiler to start the process again...continue..
We'll start by figuring out how much energy in kilowatt-hours the light bulb uses per year. We multiply how much power it uses in kilowatts, by the number of hours in a year. That gives 0.1 kW x 8,760 hours or 876 kWh. The thermal energy content of coal is 6,150 kWh/ton. Although coal fired power generators are very efficient, they are still limited by the laws of thermodynamics. Only about 40 percent of the thermal energy in coal is converted to electricity. So the electricity generated per ton of coal is 0.4 x 6,150 kWh or 2,460 kWh/ton...continue..
Fossil fuels are by far the largest source of electricity in the world today. Coal, alone, accounts for about 42% of electric power (Beck 65). Therefore, fossil fuels provide an obvious point of comparison to rate the nuclear industry's standards.
First, nuclear power has some disadvantages worthy of attention:
* Nuclear power plants have dangerously high radioactive levels. The radioactivity is entirely
contained within the plant, but the possibility exists that some of it might leak to the outside
environment during an accident. Over time, new designs, stricter regulations and better
technology are reducing the risk of radioactive leaks.
...continue..
First, nuclear power has some disadvantages worthy of attention:
* Nuclear power plants have dangerously high radioactive levels. The radioactivity is entirely
contained within the plant, but the possibility exists that some of it might leak to the outside
environment during an accident. Over time, new designs, stricter regulations and better
technology are reducing the risk of radioactive leaks.
...continue..
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