Green synthesis of biobased glycerol levulinate ketal in a continuous flow reactor: Optimization, kinetics and simulation

The development of novel biobased chemicals is of great research significance in promoting the high-value utilization of lignocellulosic biomass. Methyl levulinate glycerol ketal (MLK) as a novel biobased chemical can be used as a solvent and applied in the fields of polyurethane and coatings. In this paper, the process of continuous preparation of MLK from methyl levulinate (ML) and glycerol (GLY) was studied. The effects of different factors on the yield of MLK and the conversion of GLY were investigated, and the optimum reaction conditions were reaction temperature 140 °C, catalyst HZSM-5 0.50 g, ML to GLY molar ratio 4:1 and weight hourly space velocity (WHSV) of 1.34 h−1. Under these conditions, the conversion of GLY was 97.00% and the yield of MLK reached 94.70%. The kinetic experiments were further carried out at the temperature range of 130 °C to 150 °C, and the kinetic results showed that the activation energy and the pre-exponential factor were 64.26 kJ·mol−1 and 9.05 × 109 mol·g−1·s−1, respectively. Meanwhile, the production efficiency in the continuous process was 1.91 g·h−1 with a turnover frequency (TOF) of 9.00 h−1, suggesting a higher catalytic efficiency and catalytic activity than that in the batch process. On this basis, a process simulation of the continuous MLK preparation process was further conducted, and the techno-economic evaluation of the process was performed to provide a theoretical reference for the development of the biobased MLK process.