Removal of tar model compounds produced from biomass gasification using activated carbons

Dry gas cleaning was performed using five different commercial activated carbons (ACs) at 150-300 °C. Phenol, o-cresol, naphthalene, and 1-methylnaphthalene were employed as the tar model compounds that produced from biomass gasification. The effect of the adsorption temperature and physical characteristics of ACs on the adsorption behaviors such as the breakthrough curves and adsorption capacities was investigated using a fixed-bed reactor. At 150 °C o-cresol and naphthalene were effectively removed; the adsorption capacities of the ACs were 13,4-19.4 g-tar/(100 g-AC) and 19.9-23.7 g-tar/(100 g-AC) in o-cresol and naphthalene, respectively. For effective tar removal, a larger surface area, a smaller average particle size, and an appropriate pore diameter were necessary. The effect of the tar model compounds on the adsorption behavior was investigated using the same AC at 150 °C. The adsorption capacity was found to be 10.5-32.6 g-tar/(100 g-AC) in the following order: phenol < o-cresol < naphthalene < 1-methylnaphthalene. Tar compounds having methyl groups (o-cresol and 1-methylnaphthalene) were removed more effectively as compared to those having no methyl groups (phenol and naphthalene).