The compositions of EFBs and alkali-pretreated EFBs were determined by the National Renewable Energy Laboratory (NREL) chemical analysis and testing laboratory procedures (LAPs) of the US Department of Energy (DOE). Glucose, xylose, acetic acid, and ethanol were analyzed by HPLC with a YL 9170 refractive index detector (Young-Lin, Republic of Korea) and a Rezex ROA-Organic Acid Hþ column (7.8 300 mm, Phenomenex, USA) at 65 C. The mobile phase was 2.5 mM sulfuric acid and the flow rate was 0.5 mL/min. Ethanol yield was calculated as the percentage of the maximum theoretical ethanol yield (0.51 g ethanol per gram of glucose).