Improved production of levulinic acid from glucose with high substrate concentration via fed-batch process

Levulinic acid (LA) is an important biobased platform chemical, which can be produced from carbohydrates via acid hydrolysis. However, the LA concentaration is usually low via the batch process, which is not conducive to its subsequent separation and purification. In this study, we improved the LA production by using novel fed-batch hydrolysis. Compared with the batch process, the LA yield of the one-time feeding process and two-time feeding process increased to 38.66% and 40.60% from 27.80%, the LA concentration increased to 49.83 g/L and 52.33 g/L from 35.83 g/L, respectively. The feasibility of using the waste solid residue generated during the LA production as filler was further investigated. The polyurethane foam was prepared with the incorporation of solid residue, and the compressive strength of the biobased polyurethane foam composites increased by 32.08% with the addition of 5% solid residue. The characterization of the biobased polyurethane foam indicated the solid residue can be used for polyurethane foam enhancement. This study provided a novel method for the efficient and clean production of LA and high-value utilization of the waste produced in the process.