200 Introduction to Renewable Biomaterials
Cellulose
Cellulose
Lignin
Hemicellulose
Enlarged view
Lignin
Amorphous
region
Crystalline
region
Hemicellulose
Pretreatment
Figure 6.11Schematic mechanism of effects of pretreatment on lignocellulosic biomass.
- chemical pretreatments such as using alkaline materials, dilute acid, oxidative agents,
and organic solutions;
- physicochemical pretreatment (hydrothermal process, using steam autohydrolysis);
- biological and enzymatic pretreatments (using cellulase enzyme or microorganisms
and fungus that produce pure cellulase enzyme);
- combined pretreatments in order to achieve maximum yield.
6.7 What Is Currently Being Done and What Are the Advances?
the Advances?
Currently, most researches focus on a combination of two or more pretreatment
methods. Some of the pretreatment methods are listed in Table 6.5.
Physical pretreatment can be achieved by different methods, three types of which are
discussed in the following.
