Rice straw was pretreated with ammonium carbonate ((NH4)(2)CO3), a major intermediate of ammonia-based carbon capture process, and evaluated for the effects of critical pretreatment parameters including (NH4)(2)CO3 concentration (5-25%), temperature (60-90 degrees C), and reaction time (4-24 h) on enzymatic digestibility. Pretreatment of rice straw at 80 degrees C for 12 h using 20% (NH4)(2)CO3 and 1:10 solid to liquid ratio resulted in enzymatic digestibility of 72.2%, which was higher than that pretreated with the same moles of aqueous ammonia. We also investigated physical characteristics of pretreated rice straw, including surface area, pore volume and size, crystallinity, and scanning electron microscopy image. The ammonium carbonate pretreatment process, as a novel pretreatment technique, enhanced enzymatic hydrolysis of lignocellulose by altering structural features. (C) 2014 Elsevier Ltd. All rights reserved.