Ethanol from sugar crops : a critical review

This critical review offers information on ethanol production for development planners. Two sugar crop-based ethanol systems, raw sugar facility retrofit and conventional juice extraction, are first examined. The agronomy of sugar crops (cane, beet, sorghum) is then described, as are the steps in crop processing (extraction, fermentation, distillation, stillage disposal). The costs of producing ethanol from a typical sugarcane processing plant and from a state-of-the-art molasses processing facility are presented, and the trade-offs between producing ethanol or raw sugar from sugarcane weighed. Finally, the properties of ethanol in automotive fuels are outlined, along with important storage, handling, and safety considerations. Three major problems are cited in ethanol production from sugar crops: adverse environmental effects (10 gallons of waste to 1 gallon of ethanol); the high cost of conventional milling equipment; and the loss of potential revenue from raw sugar sales. A future possibility of producing ethanol from fibrous residues (bagasse) is noted. Included are a 64-item bibliography (1936-1980) and 31 tables.