Brown Coals: Trends in Application (Report 2)

摘要

The tendency has lately been observed for the replacement of petroleum and gas by solid fuel in the fuel balance. Analysis of technological measures used in world practice for increasing the amount of coals to be used has shown that one of the promising trends in this field is the production of an upgraded solid fuel from low-grade coals. The accelerated pyrolysis of brown coals gives a fuel for both technological and power-generating purposes [58]. In Russia, such promising technologies are being developed for brown coals of Kansk-Achinsk Basin. In FRG, according to the forecast, up to 2020 the quantity of brown coal to be burnt in power plants will be 90 percent. During the period 1995-2000 there have been built brown-coal power plants with a total capacity of 5000 MW and an efficiency of 40-42 percent; after preliminary drying of coal the efficiency amounts to 48-50 percent [59]. In Europe, with respect to expenses, for the production of electric power in a 1000-MW plant the cost of fuel based on gas is 75 percent, and for brown coal it is about 25 percent [60]. Investigations and calculations have shown that brown coals are competitive in the production of electricity [61]. The firm Energy (USA) is planning to invest more than 100 million dollars for reducing the atmospheric pollution from the Maritza East brown-coal plant. The firm has 67 percent stock in the project of construction of equipment for the plant of 840 MW. In the plant with 4 blocks the emission of SO_2 will diminish by 90-95 percent [62]. In India there will be built a brown-coal power plant with the combustion of coal in the fluidized bed with a reduction of SO_2 emissions by 90 percent. A number of new power plants with a total capacity of >=6,000 MW will be built [63].