Design and optimization of a high-efficiency distillation process for cellulosic fuel ethanol integrated with thermal coupling and molecular sieve adsorption

• A novel distillation–molecular sieve coupling process reduces total annual cost (TAC) by 15.58% and CO2 emission costs by 27.56% compared to traditional three-column distillation. • The integrated process achieves ethanol purity exceeding 99.6%, meeting fuel-grade specifications. • Thermal coupling via differential pressure design and waste heat recovery significantly lowers energy consumption. • Aspen Plus optimization with NRTL model parameters enables precise process design and economic feasibility.