ARS | Publication request: Economic analysis of ethanol production from citrus peel waste

Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 12, 2007
Publication Date: March 20, 2008
Citation: Zhou, W., Widmer, W., Grohmann, K. 2007. Economic analysis of ethanol production from citrus peel waste. Proceedings of Florida State Horticultural Society. 120:310-315.

Interpretive Summary: Ethanol production from citrus peels is attractive in Florida. Each year, the citrus industry produces 3.5 million tons of citrus peels, which are currently dried and sold as cattle feed. Recently, USDA/ARS scientists and their partner Renewable Spirits, LLC have developed a new process for making fuel ethanol and higher value co-products from citrus peels. To date, the production of citrus ethanol has advanced from bench to pilot plant scale (10,000 gallons/batch fermentation). The economic impact of citrus ethanol on the citrus industry is assessed and found favorable. The estimated production cost of citrus ethanol is approximately $ 1.23/gallon. Commercial production of citrus ethanol is economically feasible. Ethanol production from citrus peels could increase juice producers’ revenues, lower limonene emissions and create more job opportunities in Florida.

Technical Abstract: The Florida citrus juice industry produces about 3.5 million tons of wet peel waste per year. In current industrial practice, waste peels are dried and sold as cattle feed to offset the waste disposal cost. Profitability would be greatly improved if peels could be used to produce higher value products. Recent advances by USDA/ARS scientists and their partner Renewable Spirits, LLC have given rise to the potential of a new process for making fuel ethanol from citrus peel waste. In this paper, the economics of the process for making citrus ethanol is analyzed and discussed. The economic model for the cellulose-to-ethanol process was used as a benchmark to estimate the project cost and the fixed operating cost for the peel-to-ethanol process. The production cost of citrus ethanol is estimated to be approximately $1.23/gallon, possibly higher than the cost of corn ethanol ($1.00/gallon), but lower than the cost of cellulose ethanol ($1.35-1.62/gallon). This study allows us to pinpoint the economics of the process for making fuel ethanol from citrus peel waste, and is useful for predicting the cost benefit of proposed research and its economic impact on the juice industry.