Chapter 3

Chapter 3 – Lignocellulosic Biomass: Feedstock Characteristics, Pretreatment Methods and Pre-Processing for Biofuel and Bioproduct Applications, U.S. and Canadian Perspectives (pp. 61-98)

Authors:  (Kingsley L. Iroba and Lope G. Tabil, Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, Canada)
Renewable energy using lignocellulosic biomass is expected to become one of the
key energy resources in the near future to deal successfully with global warming and
depletion of conventional fossil fuel resources. This will to a large extent save our
environment and human health. The challenges involved in the production of ethanol
from lignocellulosic biomass must be critically addressed to enhance the digestibility and
accessibility of cellulose and hemicellulose, and the subsequent conversion to simple
sugars usable by fermentation yeasts. Effective conversion relies on a number of factors:
the composition and structure of the feedstock, particle size, pretreatment method used,
and type and loading of enzymes. The highly organized crystalline structure of cellulose
poses obstacle to hydrolysis. Cellulose and hemicellulose are largely protected from
enzymatic attack. This inaccessibility to attack is primarily a result of the association of
these polysaccharides with lignin, which acts as a barrier, shielding the polysaccharides.
Optimization of the pretreatment, hydrolysis, and fermentation processes with minimal
production of inhibitors will contribute immensely to an efficient and cost-effective
biorefinery industrial process. To mitigate the difficulty created by the bulky, loose, and
disperse nature of lignocellulosic biomass, there is a need for pre-processing and
densification for easy, economical, and efficient transportation, handling, and storage. It
increases mass per unit volume and improves the convenience and accessibility of
lignocellulosic biomass feedstock due to the uniform shape and size.