This study investigated the production of bioethanol from Miscanthus using a specially designed twin-screw extruder (designated CHEMET) with sodium hydroxide. Pretreatment parameters were optimized using a response surface methodology and we evaluated the efficiency of pretreatment through the biomass to ethanol ratio (BTER). Optimum pretreatment conditions were 95 degrees C, 0.4 M sodium hydroxide concentration, 80 rpm twin-screw speed, and flow rate of 120 mL/min. Under these optimum conditions, actual BTER was 66 +/- 2%, compared with a theoretical maximum of 67 +/- 3%. Simultaneous saccharification and fermentation (SSF) was used to optimize enzyme and biomass dosage, giving a maximized ethanol concentration of 67.0 g/L and an ethanol conversion rate of 88.1% for 25% loading of pretreated Miscanthus with 30 FPU/g glucose of enzyme. The findings contribute to the development of continuous-production methods of obtaining bioethanol from lignocellulosic biomass. (C) 2013 Elsevier Ltd. All rights reserved.