Page 35 - Lignocellulosic Biomass to Liquid Biofuels

Fundamentals of lignocellulosic biomass 13

and low molecular weight lignin. In this process the raw material (LCB) is
mixed with particular organic solvent, with or without acid, catalyst, and
other necessary constituents for the separating of lignin, hemicellulose,
and cellulose in solid phase. Here, catalysts are generally used for the
increasing solubilization of hemicellulose and digestibility of the
other substrate, whereas organic solvents (acetone, ethyl alcohol, ethylene
glycol, aqueous phenol, n-butanol, etc.) are used to enhance the process
readily [25].
This process is most feasible for the fractionation of LCB because of
the utilization of all the biomass components of LCB. However, some
drawbacks are associated with OF, such as high cost of organic solvent,
need extra caring to handle because of the extreme volatility of organic
solvent. No leakage is allowed here due to the possibility of heavy explo-
sion [26]. Its successful commercialization will depend on the develop-
ment of high-value coproducts from lignin and hemicelluloses.
The LCB biorefineries are used to separate or extract a wide range
of finished product by using combination of different technologies.
Fig. 1.3 shows the probable finished products (fuel and chemicals) that

Figure 1.3 Biorefinery of LCB for obtaining different finished products. LCB,
Lignocellulosic biomass.