煤结焦机理的研究——苯抽提沥青的作用

Study on Coking Mechanism of Coals——Effects of Benzene Extractable Bitumen

在2L高压釜中用苯对5种烟煤在280℃和5MPa条件下,进行了抽提出沥青和不分离出沥青的苯处理试验。结果表明,经过苯处理的煤,其结焦性能明显下降,抽出沥青后降低幅度更大。如煤样No.3的罗加指数为65,苯处理后为24,抽出沥青后则仅有14。苯处理后的煤在热解中开始软化温度比原煤略有下降,而抽出沥青后该温度则升高30～50℃。抽余煤回配沥青后,並未恢复失去的结焦性能,而仅向苯处理煤靠拢,如上述煤样的苯抽余煤回配沥青后,罗加指数仅从14增加到21。根据煤的热解机理和沥青的组成结构,讨论了后者在形成胶质体中的作用。

A series of experiments of benzene extraction (BE) and benzene treatment (BT) of five types of bituminous coals from Ruhr Kohle AG has been carried out in a 2 L. autoclave at 280℃ under 5 MPa pressure. Experimental results show that the coking behaviour of coal became strikingly bad after BT and bitumen removal by BE caused much greater deterioration. The Roga Index of coal No. 3 was originally 65; after BT it decreased to 24 and after BE to 14. The softening temperatures in coal pyrolysis decreased slightly after BT but after BE it increased up to 30～501℃ higher than that of original coals. Remixing of benzene extracted coals with bitumen did not recover the lost coking behaviour; they restored only nearly to benzene treated coals. For example, Roga Index of benzene extracted No. 3 coal increased from 14 to 21 after remixing. Based on the pyrolysis mechanism of coal and the composition of bitumen, the effects of benzene soluble bitumen on coking behaviour were discussed and new explanation was suggested.