METHOD FOR INCREASING CALORIFIC VALUE OF LOW-GRADE COALS

摘要

To provide less expensive and non-polluting coals of which calorific values are increased by improving composition of coals having high moisture content and low fire power, such as peat and lignite, to thereby increase combustion calorie. Materials of coals are heated in a predetermined temperature range in an oxygen-free atmosphere while injecting inactive gas, and elements except for carbon in the atmosphere and in the coals are individually separated by thermal decomposition in the order from an element having a lower decomposition temperature at a temperature of 450 degrees C. or lower so as to obtain upgraded coals. Since the carbon composing the upgraded coals has strong activity, the upgraded coals have quality equivalent or greater than that of the coal of ordinary quality and demonstrate combustion efficiency that has been significantly improved from those of the materials before upgrading.