Average structural analysis of tar obtained from pyrolysis of wood.

Conventional analytical methods such as (1)H NMR, vapor pressure osmometry (VPO) and elemental analysis were used to characterize the tar obtained from pyrolysis of pine. The major fraction of tar obtained during pyrolysis of pine at different temperatures was the insoluble fraction in n-heptane which corresponds to asphaltenes; this fraction was characterized and analyzed using average structural parameters. The structural unit of the tar is composed of one aromatic ring substituted by aliphatic chains, olefinic groups and the presence of oxygenated groups. Two of such average structures determined with this methodology corresponds to 4-formyl-2,6-dimethoxy-3-[(1E)-prop-1-en-1-yl]-5-propylbenzoic acid and 2,3,5-trimethoxy-6-[(1E)-prop-1-en-1-yl]-4-propylbenzaldehyde.