Citrus Waste Biorefinery: Biomass Characterization of Grapefruit Processing Waste and Potential for Bioethanol and Value Added Products
Grapefruit processing waste has, to date, not been classified as a renewable energy source. Citrus wastes (peel, pulp, and seeds) generated from juice production are almost 50 wt% of the original whole fruit. The US 2006/2008 seasons of citrus juice production generated 10.6 million metric tons of waste.
Raul C. Rivas1, Kim D. Jones1, Patrick L. Mills2, and Vanessa L. Garcia1
1Environmental Engineering Department, Texas A&M University-Kingsville
2Chemical and Natural Gas Engineering Department, Texas A&M University-Kingsville
The methods developed for this research were based on procedures established by the National Renewable Energy Laboratory (NREL), and modified to suit the abilities of a GC/MS analytical method.
In Texas, during the same period, 192,000 tons of citrus waste (Citrus paradisi Macf) was generated. The objective of this research was to develop and adapt analytical methods to characterize grapefruit processing waste (GPW) as biomass.
Modifications were also made to available spectrophotometric methods for the analysis of protein and pectin. It was found that the procedures set forth by NREL had to be elaborately tailored to fit the characteristics of GPW in order to classify it as biomass, and the spectrophotometric methods can be used as a surrogate method to quantify such parameters.
Preliminary results indicate that an approximate composition of GPW as biomass contains considerable amounts of cellulose, hemicellulose, pectin, lignin, and soluble sugars such as glucose and fructose.