Monday, August 11, 2008
P14

Use of Sugarcane Crop Residue for Fuel Grade Ethanol Production

Raj Boopathy, Biological Sciences, Nicholls State University, Hwy 1, Thibodaux, LA 70310

Sugar production is a major industry in Louisiana. In 2004, 804 producers from 23 parishes produced just over 1.2 million tons of sugar. One problem sugarcane farmers face is the post-harvest sugarcane residue in the form of leaf litter that is left after harvesting. At 3 to 10 tons residue per acre, it is a major impediment to farming practices. Currently farmers use open-air burning techniques to get rid of the residue. The open-air burning accounts for up to 21% of total air pollution in Louisiana, which is known to cause public health problems such as asthma and emphysema. Farmers are now under increasing pressure to find alternatives to open air burning. Research at Nicholls State University explores the possibilities of making alcohol from the sugarcane residue. A chemical pre-treatment process using acid hydrolysis was applied to remove lignin, which acts as physical barrier to cellulolytic enzymes. Saccharomyces cerevisiae ATCC strain 765 was used in the experiment. The pre-treatment process effectively removed lignin. Alcohol production in the culture sample was monitored using gas chromatography. The sugarcane leaf litter acid treatment of 0.8 M sulfuric acid fermenting for 12 days produced more ethanol than any other treatment combinations. The 0.8 M sulfuric acid treatment produced 335.67 mg/L ethanol in 12 days. Fermentation for more than 12 days did not increase ethanol production. The fermentation system needs to be optimized for evaluating the economics of producing ethanol from the sugarcane residue.