ABSTRACT
The mix of high-sulfur lignite with cedarnut shell of high K2O content in ash was combusted in a fluidized bed reactor. When grain size distribution was identical, SO2 emission was the same as in the case of lignite alone. Under the same conditions, co-combustion of bituminous coal with cedarnut shells showed a significant drop of the SO2 emission. Reduction of SO2 emission was obtained by increasing the lignite grain size in order to extend the process of its combustion. When the lignite grain size was three times larger than the biomass grain size, the SO2 emission was 50% of the previous value, when six times larger it was 30%. This means that S retention takes place when SO2 released during lignite combustion is in direct contact with the biomass mineral residues. The most significant SO2 emission reduction occurred when lignite was combusted with biomass ash, not with raw biomass.
Acknowledgments
The authors would like to thank Mr. Jacek Pasierb and Mr. Piotr Mondkiewicz (AGH) for their technical assistance.