DEVELOPMENT OF NEW SULFUR RECOVERY METHOD USING ACTIVE CATALYST FOR GASIFICATION OF CARBON

利用碳与SO_2的气化反应可以从含SO_2气体中回收单质硫。在SO_2气氛下，用热天平对褐煤和无烟煤的半焦进行了气化实验。气化温度为923 ~ 1123 K，SO_2浓度为5.3vol%。所有煤焦的实验结果都显示出一种特殊的反应曲线。在气化初期，试样重量逐渐增加，然后又逐渐减少。其原因可能是SO_2气体在半焦表面的吸附以及半焦中矿物质与SO_2的反应。失重的原因是煤焦的SO_2气化。对低阶煤焦的分布进行了观察。用盐酸洗涤三种煤以阐明矿物质对气化速率的有效性。用几种催化剂对澳大利亚褐煤Yallourn煤进行了浸渍处理。碳酸钾、氢氧化钠、氢氧化钙、氢氧化镁和硝酸铁用作催化剂浸渍的起始材料。金属与煤的重量比为1：10至1：100。反应曲线受金属添加的影响。碱金属催化剂的加入大大提高了气化速率。铂催化剂对含氧表面络合物的形成有很大影响。

Elementary sulfur can be recovered from SO_2-containing gas by a gasification reaction between carbon and SO_2. Gasification of coal chars ranging from brown coal to anthracite was carried out in SO_2 atomsphere using thermo-balance. The gasification temperature ranged form 923 to 1123 K.The SO_2 concentration was 5.3vol%. A peculiar reaction profile was observed for all coal chars exanined. The sample weight gradually increased in the earlier gasification stage, and then decreased. The increase in weight may be due to the adsorption of SO_2 gas to char surface and to the reaction between mineral matter in char and SO_2. The weight decrease is due to the SO_2 gasification of coal char. The profile was obseved for low rank coal chars. three coals were washed with hydrochloric acid to elucidate the effectiveness of mineral matter on the gasfication rate. The treatment apprecably reduced the gasification rate.Yallourn coal, Australian brown coal, was impregnated with several catalysts. Potassium carbnate, sodium hydroxide, calcium hydroxide, magnesium hydroxide and iron nitrate were used as the starting materials for catalyst impregnation. The metal to coal ratio was ranged from 1 : 10 to 1 : 100 by weight. The reaction profile was affected by the addition of metals. The gasification rate was enormously enhanced by the addition of alkaline metal catalyst. Ptassium catalyst greatly affected the formation of oxygen-containing surface complex.