Component fractionation of wood-tar by column chromatography with the packing material of silica gel

Bio-oil can be an important fuel resource for automobiles in the future, while its complex composition restricts the direct application of the bio-oil extremely. So it is necessary to separate the complex mixture to relatively simplified fractions for goal directed specific treatments to reach the fuel quality for automobiles, and meanwhile different functional chemical materials and fine chemicals can be obtained. So it is significant to investigate the bio-oil component separating methods. Herein the method of column chromatography by the packing material of silica gel with two series of eluants of cyclohexane-benzene-methanol and cyclohexane-dichloromethane-methanol were investigated for component fractionation of the raw wood tar (oil fraction of the liquid product by slow pyrolysis of wood). The analytical results show that the components in cyclohexane are rich in alkoxyl-monophenols; the components of alkyl-monophenols and five ring oxygen-containing compounds are abundant in benzene and in dichloromethane similarly; in the methanol fraction, the components are diverse and diphenols are relatively in higher content, comparatively small polar molecules and five ring oxygen-containing compounds are more abundant in the methanol fraction after being eluted by dichloromethane, and the content of 1-(4-hydroxy-3-methoxyphenyl) -2-propanone is higher after being eluted by benzene.