In this paper, we have characterized the black liquors from oxygen-org
anosolv pulping of Eucalyptus globulus wood in ethanol/water solutions
(50:50, V/V) and acetic acid/water solutions (80:20, V/V). After pulp
separation, the organic solvent has been distilled and recycled; the
precipitated lignin has been recovered by filtration. The degradation
products in solution have been easily separated by simple extraction t
echniques. Five main groups of compounds have been isolated: solid lig
nin (11-12% o.d.w.), sugars (10-17% o.d.w.), aliphatic acids (12,5%),
aromatic acids (2% o.d.w.) and low molecular weight phenols (1% o.d.w.
). Most of these compounds were identified by HPLC and GC. Solid ligni
ns have been analyzed by FTIR and C-13 NMR spectroscopy. It has been C
oncluded that oxygen-organosolv pulping process can be a new and inter
esting way for pulp preparation with little pollution and possibility
of total biomass recovery; alternatively, it can be used for the fract
ionation and valorization of the components of lignocellulosics, inclu
ding agriculture residues.