1-3-1 褐炭のin-situ水蒸気ガス化特性に及ぼすイオン交換担持触媒の効果(1-3 ガス化2,Session1 石炭・重質油等,研究発表)

概要

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Costs of catalyst are crucial for industrial application of catalytic gasification. Sodium and calcium salts are abundant and cheap resources, and potentially excellent catalysts of the low rank coal gasification. Steam gasification of Na-, Ca- and Na/Ca-ion-exchanged Adaro brown coal was therefore investigated with an atmospheric drop-tube reactor at 850-1000℃ under the steam partial pressure of 0.05 MPa. The Na and Ca were loaded onto the coal by ion-exchange from aqueous solutions of soda ash (Na_2CO_3) and slaked lime (Ca(OH)_2), respectively. The catalyst contents for Na, Ca, and Na/Ca ion-exchanged coals were 1.5, 3.2, and 0.36/3.0 wt% respectively. The Na/Ca ion-exchanged coal showed the highest activity toward gasification, and exhibited the char yield of 43mol-C/100mol-C-Coal at 900℃. Increasing temperature to 1000℃ enhanced the gasification of Na/Ca ion-exchanged coal reducing the char yield down to 21mol-C/100mol-C-Coal. The XRD analysis of the chars resulting from the gasification of ion-exchanged coals at 900℃ revealed that Na_2CO_3, CaCO_3, and CaO were retained by the chars, with average crystalline sizes of 15-23 nm. The Na/Ca catalysts were thus finely-dispersed over the char surface, and their catalytic activities were maintained at a certain level during the gasification.
2011-08-09