MULTISTAGE REACTOR FOR THERMAL GASIFICATION OF WOOD

Tar is the most undesirable contaminant of producer gas. Production of tar-free gas from uncarbonized biomass seems to be rather elusive, an d removing tar from the gas remains a daunting task requiring bulky, e xpensive equipment and considerable operational effort. A new multi-st age reactor design has been developed in order to separate the flaming -pyrolysis zone from the reduction zone. Tar vapors generated in the f irst zone are burned or cracked to simple molecules by high temperatur e in the second zone. Data obtained from experimental tests show that the two-stage reactor has improved gas quality and conversion efficien cy. The tar content of the gas is about 40 times less than that obtain ed with a single-stage reactor under similar operating conditions.