Kinetics and Dynamics of Conversion of Bambusa Bamboo into 5-Hydroxymethylfurfural in Ionic Solvent in Batch Reactor

Abstract

In this era of industrial revolution and diminishing petroleum reserves, alternative options (woody biomass) for building next-generation fuels need to be critically explored. Here, process engineering aspects of 5-hydroxymethylfurfural (5-HMF) from Bambusa bamboo in ionic liquid ([Bmim]Cl) in the presence of a catalyst, CrCl₃, in batch reactor have been explored in great detail. 5-HMF upon hydrogenation liberates 2,5-dimethylfuran (DMF), which is a liquid fuel. To maximize the production of platform chemical-5-HMF, effects of different mixing speeds (150–1200 rpm) and temperatures (120–160 °C) were captured on the yield of 5-HMF and glucose. A highest 5-HMF yield (25%) was obtained at 120 °C and 1200 rpm within a reaction time of 6 h. Moreover, a kinetic analysis of transformation of biomass into 5-HMF was carried out using curve fitting to estimate kinetic constants k₁, k₂, and k₃. Mixing at asymptotic limits, i.e., no mixing (0 rpm) and very high mixing (1200 rpm), enables us to devise mixing regimes: 0–400 rpm, mass transfer–limited regime; 400–1100 rpm, intermediate regime; and > 1100 rpm, reaction-limited regime. Thus, tremendous improvement in reaction rate constants (k₁, k₂, k₃) was observed when operated at higher mixing conditions (reaction-limited regime). Mixing limitation for this IL-based system can be eliminated by operating the reactor above 800 rpm, whereas lower temperature restricts conversion of 5-HMF to LA and FA. Hence, higher mixing speeds, i.e., > 1100 rpm, and lower temperature, i.e., ≈ 120 °C, can be suggested as the optimum operating conditions for maximization of platform chemical-5-HMF in the catalytic conversion of Bambusa bamboo in batch reactor.