Abstract
•A novel US/ILs hybrid concept is investigated numerically toward cellulose decomposition.•Acoustic cavitation threshold is higher in terms of power in the ionic liquid.•The oscillation dynamics is limited by the viscosity of [C4mim][CH3COO].•The temperature in the boundary layer attains 1000 K at the mid-width.•High cellulose decomposition and anhydrocellulose emergence rates are recorded.
The present paper reports a numerical investigation of the feasibility of a hybrid concept associating the 1-Butyl-3-methylimidazolium Acetate [C4mim][CH3COO] to sonication, in terms of cavitation formation and generated extreme conditions allowing cellulose decomposition in the second reactivity site. The results of the proposed model revealed an acoustic power threshold of 1.8 atm, in order to expect a transient cavitation in the ionic liquid, leading to harsh conditions of 1559.8 K and 49 bar within the bulk volume of the acoustic cavitation bubble. The spatial and temporal variation of the temperature was simulated within the bulk volume of the bubble as well as in the thermal boundary layer jointly with the chemical kinetics. The first stage of the polymerization reduction was clearly attained and demonstrated through the decomposition rate of cellulose and the molar rate of emergence of anhydrocellulose, reaching the respective orders of magnitude of 1.71 × 104 mol/m3⋅s and 7.91 × 104 mol/m3⋅s.