A wet packed-bed scrubber for removing tar from biomass producer gas

Abstract In this work, we report the performance of a lab scale wet packed-bed scrubber using woodchips as a packing material. Wood chips were wetted by waste cooking oil which acted as a scrubber medium. Residence time of 8.5 s was comparable to the packed-bed filter used in a pilot scale gasifier. We studied the effects of oil/gas ratio (4.7 and 7 m3/s/m3/s × 103), oil temperature (ambient, ~23 °C and 50 °C) and woodchips size (coarse = ~0.02–0.045 m, 0.003–0.03 m and 0.002–0.007 m and fine = (0.015–0.04 m) × (0.002–0.005 m) × (0.001–0.003 m)) to remove tar model compounds from producer gas. The results demonstrate liquid to gas ratio has significant effect (p-value = 0.002) on removing toluene as tar model compound; next important parameter is bed configuration (p-value = 0.014), impacting toluene removal efficiency. For naphthalene, oil flow rate (p-value = 0.022) and bed configuration (p-value = 0.024) have almost similar effects. Oil temperature has relatively lower impact on removing tar.