The assessment of synergistic effect on performing the co-pyrolysis process of coal and waste blends based on thermal analysis

The preliminary thermogravimetric studies of co-pyrolyzed low-rank coals (lignites Kostolac (KSL) and Kolubara (KLB)) with waste materials (spent coffee ground (SCG) and tire rubber granulate (WRG)) in a form of blends have been performed. Thermal analysis (TA) measurements of blend samples were carried out in a nitrogen (N2) atmosphere at three different heating rates of 10, 15 and 20 K min-1. The coal-waste blends were prepared in the percentage ratios of 90:10, 80:20 and 70:30. This work analyzed the synergy analysis for considered blends shown via descriptive parameters during co-pyrolysis process. According to the performed analysis, the presence of synergistic effect was identified, where strong interactions were also observed. For lignite-SCG blends, it was found that two factors which affect the synergy effect with coal are concentration of added biomass material and the heating rate. For lignite-WRG blends, the blending ratio take on a decisive role for positive consequences of a synergistic effect (ratios below 30 % of WRG in coals are desirable). Also, in this work the influence of micro-scale condition parameters such as heating rate (as the experimental regulatory factor) was analyzed on the magnitude response of synergism during co-pyrolysis.