Coconut coir fibers, which analyzed 34.8% glucan, 183% xylan, 35.8% lignin and 8.7% extractives, were pretreated with acidified aqueous glycerol (10% water) at a solid/liquid ratio loading of 1:20 and 1:30, a temperature of 130 degrees C and 60,30, and 15 min contact time. The maximum yield of glucan digestibility was 79.7% and 81.8% for the respective solid/liquid ratios for 30 min of pretreatment. The simultaneous saccharification and fermentation was conducted anaerobically at 37 degrees C with Saccharomyces cerevisiae, 5% w/v glucan, and 10 FPU/g glucan of cellulase. The highest ethanol concentrations obtained after 3 days of incubation from pretreated coconut coir fiber were 8.97 and 8.81 g/L, respectively, for the samples pretreated with acidified aqueous glycerol at 1:30 and 1:20 solid/liquid loading ratio for 30 min. (C) 2017 Elsevier Ltd. All rights reserved.