Evaluating removal of tar contents in syngas produced from downdraft biomass gasification system

Abstract

Biomass gasification is a process of converting solid biomass ingredients into a combustible gas which can be used in electricity generation. Regardless of their applications in many fields, biomass gasification technology is still facing many cleaning issues of syngas. Tar production in biomass gasification process is one of the biggest challenges for this technology. The aimed of this study is to evaluate the tar contents in syngas produced from wood chips and corn cobs as a biomass fuel and tar removal efficiency of different cleaning units integrated with gassifier. Performance of different cleaning units, i.e., cyclone separator, wet scrubber, biomass filter, and auxiliary filter was tested with two biomass fuels. Results of this study reported that wood chips produced less tar 6,600 mg/Nm3 as compared to corn cobs 7,500 mg/Nm3 in biomass reactor stage before cleaning. After passing through the whole cleaning system, the tar concentration in case wood chip reduced from 6,600 to 112 mg/Nm3, while in case of corn cob from 7,500 to 220 mg/Nm3. Overall tar removal efficiencies of cyclone separator, wet scrubber, biomass filter and auxiliary filter was noted as 72%, 63%, 74%, 35 %, respectively.