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 (559Kb)
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21,752,000 Yen (FY1996 7,225,000 Yen)
To establish the control technique of emission of SOx and NOx which cause the acid rain, a sulfur removal process for coal combustion was examined. The usage of coal briquette was investigated for the small and medium size stoker boilers which requires immediate measures. The concept of this method is to replace the fuel from usual caol to coal briquette which containing the sorbent.
At the first step, lab-scale experiments were carried. Results are as follows. The SOx removal efficiency was about 60 to 70 percent when Ca/S=4. It is however difficult to remove the sulfur oxides emitted when the volatile matters burns. Therefore, some measures should be added to the period. When limestone was compared as an absorber with hydrated lime, hydrated lime was effective. A remarkable influence was not seen in the SOx removal efficiency with any condition of molding pressure of molding pressure of coal briquette from 1 to 3t/cm2.
As the next step, the coal briquette method was applied to a stoker boiler in China. One of typical stoker boilers in China was selected as a model boiler. The model boiler is operating in the glass machine plant at Shenyang city, the biggest city in the northeastern area of China, for heating in winter season. The SOx and NOx emissions and the operating condition of the boiler were investigated at the situation of no desulfurization process. The SOx eimssion was about 600ppm and NOx was about 180ppm in usual operation. When the coal briquette with 2 of Ca/S molar ratio was used as fuel, the desulfurization efficiency became about 70% and SOx emission level became about 140ppm. Operavility in stoker boiler with coal briquette was almost excelent. Therefore, the coal briquette method seems to be a practicable measure to reduce SOx emission in Eastern Asia.
Eastern Asia, Acid Rain, Coal Combustion, SOx, Desulfurization, Coal Briquette