Abstract
The main objective of this work is to determine the kinetics of a fast, economically viable process for the conversion of lignocellulose (Ricinus communis) to fuel products such as 5-hydroxymethylfurfural (HMF) – the platform chemical, along with the production of glucose for bioethanol production. Here, we perform ionic liquid ([BMIM]Cl) based catalytic conversion of Ricinus communis (Castor leaves/tree mixtures) under the influence of microwave radiations with CuCl2 as a catalyst in a microwave reactor. The lignocellulosic substrate is first depolymerized into glucose, which then converts to HMF that further dissociates into levulinc acid (LA) and formic acid (FA). We focus on experimental determination of the optimal water addition and microwave heating profile (temperature and pressure) for maximizing the HMF yield from Ricinus communis in [BMIM]Cl aided with CuCl2 catalyst. Our kinetic model along with a Power Law model (for the dehydration of HMF and conversion of HMF to LA) and Biphasic Model (for lignocellulose hydrolysis) for quantifying the temporal dynamics of glucose and HMF production uses our understanding of the crucial role that water plays in determining the product distribution. The effect of pre-treatment on the lignocellulosic substrate has also been analyzed using FESEM (pore structure, size and density), BET (pore-surface analysis), Particle Size Analyser and XRD (extent of crystallinity). The microwave reactor helps align the dipoles in the electromagnetic field created by the combination of ionic liquid and microwave radiation, thus reducing the total reaction time drastically to 35 - 50 min, while our novel water addition strategy allows us to manipulate the production distribution for maximizing the conversion of lignocelluloses to HMF via glucose.
