Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Chemical Engineering (MS)

Administrative Home Department

Department of Chemical Engineering

Advisor 1

Rebecca Ong

Committee Member 1

David Shonnard

Committee Member 2

Judith Perlinger


Plant matter contains waxes and lipids that can be extracted and used or sold as a value-added product prior to conversion of the remaining plant material to biofuels. Wax and lipid extraction of plant materials is currently performed using volatile, non-renewable hydrocarbons, primarily hexane, which is produced from fossil fuels and can pose a health and safety hazard. The purpose of this study is to compare the amount and characteristics of waxes extracted by hexane with those extracted using organic solvents that are less toxic and can be produced from renewable sources.

Sorghum samples were extracted separately with hexane, 2-methyltetrahydrofuran (MeTHF), and diethoxymethane (DEM). Each solvent was used to conduct extractions at 25 °C, 40 °C, 60 °C, and 80 °C. The amount of wax extracted was determined and samples analyzed using GC-MS. The extractions using MeTHF produced the most lipids, followed by DEM, and then hexane. However, the lipids extracted using hexane contained desired waxes that were not found in the extracts of the other solvents. Therefore, hexane can be used to produce the highest quality waxes via extraction from sorghum. None of the solvents produced pure waxes and would require further purification.

Following extraction, the biomass was fractionated using a γ-valerolactone (GVL) pretreatment. The quantity of the lignin obtained as well as the quality of the sugars was analyzed. The amounts of lignin collected varied based on the extraction solvent, with biomass extracted using DEM producing the most, followed by MeTHF, and hexane.