ARS | Publication request: Technical and economic assessments of ethanol production from citrus peel waste

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2008
Publication Date: April 23, 2008
Citation: Zhou, W., Widmer, W., Grohmann, K. 2008. Technical and economic assessments of ethanol production from citrus peel waste. Florida State Horticultural Society Meeting. Paper No. HP22.

Technical Abstract: Each year, the Florida citrus juice industry produces about 3.5-5.0 million tons of wet peel waste, which are currently dried and sold as cattle feed, often at a loss, to dispose of the waste residual. Profitability would be greatly improved if the peel waste could be used to produce higher value products. In this paper, a new process for making ethanol and limonene co-product from citrus peel waste is described. The process consists of three parts: pretreatment, simultaneous saccharification and fermentation (SSF), and distillation. Our pilot plant study has demonstrated that citrus peels can be fermented to produce ethanol with limonene and citrus pectin fragments obtained as co-products. The sensitivity study shows that citrus ethanol is economically competitive to citrus pulp pellets, depending on the prices of citrus pulp pellet, energy, ethanol and limonene. This new technology provides an alternative disposal of citrus peel waste in the citrus industry.