A vacuum fixed bed reactor was applied to pyrolyze lignite, biomass (rice husk) and their blend with high temperature (900 degrees C) and low heating rate (10 degrees C/min). Pyrolytic products were kept in the vacuum reactor during the whole pyrolysis process, guaranteeing a long contact time (more than 2 h) for their interactions. Remarkable synergetic effects were observed. Addition of biomass obviously influenced the tar and char yields, gas volume yield, gas composition, char structure and tar composition during co-pyrolysis. It was highly possible that char gasification, gaseous phase interactions, and secondary tar cracking were facilitated when lignite and biomass were co-pyrolyzed. (C) 2014 Elsevier Ltd. All rights reserved.