Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 1, 2005
Publication Date: March 1, 2005
Citation: Dien, B.S., Iten, L.B., Skory, C.D. 2005. Converting herbaceous energy crops to bioethanol: a review with emphasis on pretreatment processes. In: Hou, C.T., editor. Handbook of Industrial Biocatalysis. Chapter 23. Boca Raton, FL: Taylor & Francis Group. p. 1-11. Technical Abstract: Both the U.S. and European Union have had ongoing research programs for the production of herbaceous perennials for use in energy generation since the mid-1980's. The candidates identified for further development, based primarily on biomass yields per acre, were: switchgrass (Pancium virgaum), miscanthus (Miscanthus spp.), reed canarygrass (Phalaris arundinacea), and giant reed (Arundo donax). Harvested biomass can be transformed to energy either by combustion to run a steam turbine, chemical conversion to syngas, or by biochemical conversion to ethanol. This paper reviews the state of technology for conversion to ethanol. Converting biomass to ethanol requires first chemically pretreating the biomass for efficient enzymatic digestion, converting the polymers (e.g., cellulose) to free sugars, and fermenting these sugars to ethanol. Pretreatment strategies developed for biomass conversion include acid and alkali catalyzed reactions. Important factors include chemical and water usage, reactor complexity, and subsequent digestibly of biomass to free sugars.