石炭の急速水素化熱分解における硫黄の挙動

Abstract

The behavior of a variety of sulfur forms in coal is complicated in the hydropyrolysis prior to hydrogasification. The desulfurization characteristics which relate closely to the development of hydrogasification technology have been sur-veyed by giving attention to the process of change in the sulfur forms in the rapid hyd-ropyrolysis of coal.The variety of sulfur forms in coal is firstly described by referring to their origin. Experimental results are secondly shown concerning to the behavior of sulfur when steam coals are pyrolyzed under a slow heating condition in a hydrogen stream at nor-mal pressure. A desulfurization model proposed by the author and coworkers has been introduced with some simulated results. Pyritic and organic sulfur forms in solid are interrelated together through hydrogen sulfide in gas phase.Observed values are thirdly explained kinetically by the model for change in the sulfur-form distribution when coals are hydropyrolyzed rapidly with a heating rate 6×103°C/sec and a terminal temperature 960°C by using a free fall pyrolyzer. Good performance is noted that maximum extent of desulfurization 92% was achieved through the efficient reduction of organic sulfur which is hard to decrease with physic-al desulfurization methods. The desulfurization rate of organic sulfur strongly de-pends on the increase rate of internal surface area accompanied with hydropyrolysis. The difficulty of decomposition of refractory organic sulfur is another factor which de-termines the final extent of desulfurization.