Valorization of Sugarcane Molasses into Bioethanol Using an Integrated Distillation-Adsorption System (I-DAS) with 3 Å Zeolite Molecular Sieve

Abstract

Sugarcane molasses is a sugar-industry by-product rich in fermentable sugars and has potential as a renewable feedstock for bioethanol. This study evaluated bioethanol purification using an integrated distillation-adsorption system (I-DAS) with a 3 Å zeolite molecular sieve at sample-setting temperatures of 85, 90, and 95 °C and one or two sequential purification cycles. Molasses was diluted and fermented for 96 h using Saccharomyces cerevisiae. Distillate was collected in 100 mL fractions and monitored using alcoholmeters, while selected samples were verified by GC-FID. Descriptive results from three replicates showed mean ethanol concentrations of 64.7–65.6% after the first cycle and 81.59–85.00% after the second cycle. A selected product obtained at 95 °C contained 95.95% ethanol by GC-FID.. Process yield decreased from 35.70–41.00% in the first cycle to 19.30–24.00% in the second cycle, indicating a purity-recovery trade-off. Total sugar decreased from 34.11% to 16.12–17.72% after fermentation and 4.17–4.43% in the final product. The I-DAS system therefore shows potential for high-purity bioethanol production from molasses, although product recovery and process control require further optimization.