Novel uses of lignin and hemicellulosic sugars from acid-hydrolysed lignocellulosic materials
Lignocellulosic materials (LM) are an ever present renewable and available
energy source. The energy stored by photosynthesis in the form of vegetation is about
ten times more than world's annual energy consumption (Zsuffa, 1982). This source
is the only alternative for chemical production after fossil fuels.
Formation of organic acids (mainly acetic acid) from hemicellulose during steam
treatment of LM leads to acid hydrolysis of cell wall components. Solubilization of
hemicellulose and depolymerization of lignin are the most important changes that occur
during the process.
During hydrolysis of LM appreciable amounts of sugar degradation products,
organic acids and phenolics are produced. Inhibitory effects of the compounds on yeast
during alcoholic fermentation have been reported and several methods have been
proposed to overcome the problem. Among the new compounds phenolics derived from
lignin depolymerization have received most attention. Another problem during enzymic
saccharification of cellulose is partial inactivation of cell free enzymes.
The above mentioned constraints were investigated in this study.