ABSTRACT
Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in biochemical production in a biorefinery context. However, it is necessary to pretreat biomass to enhance the yield of the bioethanol before the bioethanol production through hydrolysis and fermentation of biomass. The milling pretreatment as a mechanical pretreatment has been one of these pretreatment methods intensifying primarily in the research fronts of ball milling (BM), disk milling (DM), and hammer milling (HM). The most prolific biomass has been agricultural wastes, cellulose, wood, and to a lesser extent plants. Furthermore, on individual terms, the most prolific biomass has been cellulose, wood, straw, and to a lesser extent corn stover, wood chips, sugarcane bagasse, corn, grass, algae, food wastes, and corncobs. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Although there have been several review papers on the milling pretreatment of biomass, there has been no review of the 25 most-cited articles in this field. Thus, this book chapter presents a review of the 25 most-cited articles in this field. Then, it discusses the key findings of these highly influential papers briefly and comments on future research priorities in this field.
