Changes in properties of tar obtained during underground coal gasification process

Abstract In this study, the composition of tars collected during a six-day underground coal gasification (UCG) test at experimental mine ‘Barbara’ in Poland 2013 was examined. During test, tar samples were taken every day from liquid product separator and analysed by methods used for testing properties typical coke oven (coal) tar. The obtained results compared with each other data As progressed, decreasing trend water content an increasing ash observed. tested characterized large changes residue after coking parts insoluble toluene smaller fluctuations quinoline. All very high distillation losses, while starting third gasification, clear decrease losses visible. A chromatographic analysis showed that there no major differences between none had dominant component such as naphthalene polycyclic aromatic hydrocarbons (PAHs) UCG is several times lower than No light monoaromatic (benzene, toluene, ethylbenzene xylenes—BTEX) found tars, which fact these compounds, due to their volatility, did not separate process gas separator.