Power generation coal-fired

Even with an aggressive energy conservation program, the growing population will continue to demand increasing amounts of electricity. Identify and describe the environmental impacts, both positive and negative, of the two means of power generation coal-fired steam boilers and nuclear power. 

Speight JG. Electric power generation, coal-fired power generation handbook. John Wiley Sons Inc. 2013. 

In the context of this chapter and electricity generation (power generation), coal plays a vital role worldwide. Coal-fired power plants currently fuel 41% of global electricity. In some countries, coal fuels a higher percentage of electricity. 

Data for the reference system—coal-fired electricity—are adapted from Loi et al. s study [46], the Ecoinvent database for rest of world (RoW) [47], technical reports of PECCI [42], and GIZ-GDE/MOIT s report [48], in combination with calculation results following the guidelines of the AustraHan National Greenhouse Accounts and the National Pollutant Inventory Emission estimation technique manual for Fossil Fuel Electric Power Generation [49,50]. Fig. 14.3 illustrates different processes of generating coal-fired electricity. 

The cost of coal is of some concern, more so in places ofher fhan in fhe United States. It has been reported that the world-wide average price of coal increased from about 60/ton at the beginning of 2007 to 120/ton at the end of 2007. That tremendous increase has not been the case in the United States. Still at 30 to 40/ton (typical cost for western coal delivered to fhe Midwest or east), the fuel cosf for generating power in coal-fired plants in the... 

International MHD Programs. A number of countries are conducting programs in coal-fired MHD power generation. Detailed descriptions of these programs can be found in Reference 65. A summary is given in Table 6. 

Lower power ratings of reactors provide greater dexibiUty for a utihty to add power generation to a system (19). The AP600 uses prefabricated modules to shorten the constmction time. Thus constmction and operating costs are expected to be competitive with coal-fired plants. 

In 1956, the world s first commercial nuclear power plant started operation in England. By the 1960s, many nuclear power plants were built worldwide. At the end of the twentieth century, nuclear generating plants are used widely by U.S. electric utiHties. Since 1984, these plants have provided the second largest share of total U.S. electricity generation, 21% of annual GW-h generated, behind coal-fired power plants (see Nuclearreactors). 

Combustion. Most of the mined coal is burned to produce steam for electric power generation (qv). The calorific value determines the amount of steam that can be generated. However, the design and operation of a boiler requires consideration of a number of other properties (see Furnaces, FUEL-FIRED). 

A primary concern in coal-fired power generation is the release of air pollutants. Limits on SO2 output, 0.52 g/MJ equivalent of coal input to a new plant, have been estabflshed. Eor a bituminous coal of 27.9 MJ/kg there is thus an upper limit of 0.72% sulfur content. Relatively few coals can meet this requirement. The U.S. Department of Energy indicated recoverable reserves of 420 x 10 t in 1987 (2) that were categorized by sulfur content 33.5% had 0.6% S or less, 15.4% had between 0.61% and 0.83% S, 16.1% had between 0.84 and 1.67% S, 12.4% had between 1.68 and 2.50% S, and 22.6% had more than 2.5% S. The lowest sulfur coal, 86%, is found west of the Mississippi River, mainly in Montana and Wyoming, quite distant from the electric power demand centers in the East. A trend to utilization of the western coals has developed. 

In 1983 there were 116 flue-gas desulfurization (FGD) systems in service, representing 47 gigawatts-electric of power generation capacity (66). As of 1992, more than 150 coal-fired boilers in the United States operated with FGD systems. The total electrical generating capacity of these plants has risen to 72 gigawatts (67). FGD processes are classified into (/) wet-throwaway, (2) dry-throwaway, (J) wet-regenerative, and (4) dry-regenerative processes (68). 

Water Consumption and Effluent Characterization. Another advantage of CGCC power generation is derived from lower water requirements. Because more than half of the power generated in a CGCC plant comes from the gas turbine, the water requirement is only 70—80% of that required for a coal-fired power plant, where all of the power is generated from steam turbines. 

If all these process and economic advantages are reahzed, the cost of electricity l be lowered, making circulating PFBC an extremely attractive coal-fired option for power generation. 

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