A model for optimizing the enzymatic hydrolysis of ionic liquid-pretreated lignocellulose

Miscanthus x giganteus was pretreated with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate at ten different pretreatment temperatures and times. The enzymatic hydrolysis of the pretreated Miscanthus to glucose and xylose was measured as a function of time to provide rate and final conversion data. A series of two irreversible, first-order reactions with Arrhenius temperature dependencies was used to model both the cellulose and hemicellulose pretreatment. This kinetic model was used to predict the enzymatic hydrolysis conversion of IL pretreated Miscanthus over a range of pretreatment temperatures (70-140 °C) and times (1-48 h), and indicated a wide range of optimal pretreatment conditions, from high temperatures/short times to lower temperatures/long times. Pre-exponential constants and activation energies obtained from the kinetic model are within reported ranges of experimentally obtained values for other pretreatments, indicating that the model may be broadly applicable to a variety of lignocellulosic pretreatment processes.