Influence of briquetting and coking parameters on the lump coke production using non-caking coals

Abstract

In terms of transforming the energetic usage to the material usage of low-rank coals, the production of lump coke is a promising perspective. Therefore, two essential steps are necessary: Firstly, the processing and agglomeration of the non-caking coal is highly important, since they do not offer any baking capacity and thus the reachable quality of the coke is mainly set by the briquette quality. Secondly, to obtain high quality cokes the briquettes need to be coked using a well-adapted heating regime to ensure the gentle degassing of volatile matter with a minimum weakening of the briquette structure. The brown coal high temperature technology (BHT technology) developed in 1952 by Rammler and Bilkenroth was a milestone in coal conversion for brown coal but the coke strength was limited at that time. In current systematic studies, the lump coke quality of Lusatian brown coal and Indonesian brown coal was investigated varying the processing, briquetting and heating regime in laboratory scale. Those investigations should lead to a new processing and agglomeration technology to create lump coke from non-caking coals. The experiments varying the processing parameters of the coal showed that the briquetting of pre-granulated coal or pellets from a modified flat die press achieve the highest increase in briquette and coke quality. In the second step, the heating regime during pyrolysis was investigated. The results show, that the highest coke quality may be achieved using the Vollmaier regime. However, a single-stage heating regime with a heating rate of 2.85Kmin−1 shows promising results as well.