Cellulosic Feedstock.Besides the so called first generation feedstock which is received from sugar and starch crops, cellulosic feedstock is a promising source for bioethanol production in the future. Since the technology for converting cellulosic feedstock into ethanol is not yet competitive, this feedstock is a second generation feedstock. Bioethanol production from cellulose is expected to significantly expand in the future, when technologies will improve. Subsequently, cellulosic wastes and biomass that is specifically cultivated for energy purposes will be discussed in detail. Figure 1. Primary cellulosic wastes, such as forest waste (left) and agricultural residues (right)
Primary cellulosic wastes are produced during production and harvesting of food crops such as e.g.,
straw, corn stalks and leaves. Also residues from forestry such as e.g. wood thinning from commercial
forestry belong to primary cellulosic wastes. These types of biomass are typically available in the field or
forest and must be collected to be available for further use. Thereby attention has to be paid as there are long-
term economic and environmental concerns associated with the removal of large quantities of residues from
cropland. Removing residues can reduce soil quality, promote erosion, and reduce soil carbon, which in turn
lowers crop productivity and profitability. But, depending on the soil type, some level of removal can be also
beneficial. Establishment and communication of research-based guidelines is necessary to ensure that
removal of residue biomass is done in a sustainable manner [3-4]
Secondary cellulosic wastes are generated during the production of food products and biomass
materials. This biomass include nut shells, sugar cane bagasse, and saw dust, and are typically available at
e.g. industries for food and beverage production as well as at saw and paper mills.
