Optimization of Distillation of Water-acetone Mixture in the Production Process of Cellulose Acetate Fibers

Abstract In certain textile industries, acetone is used as a solvent in the production of cellulose acetate fibers. Since it is not added to the final product, its recovery at the end of the process is necessary, mainly due to economic and environmental factors. This study examined the pressure modulation distillation process of acetone/water in a cellulose acetate fiber production plant and performed a sensitivity analysis of the main process parameters (steam flow rate, reflux ratio, and column pressure) to evaluate the best operating point concerning energy consumption and process specifications. Using the NRTL-RK parameter set in the ASPEN Plus® computational environment, the proposed model satisfactorily represented the system's operation, achieving a 98.9% acetone recovery. The sensitivity analysis of the pressure modulation distillation system defined the best process operating point (pressure, reflux ratio, and steam flow rate), reaching a 97.0% purity and a flow rate of 3964 kg/h. The studied pressure modulation distillation system operated with a 15.6% reduction in steam consumption when operated at 4.4 bar and a 1.75 reflux ratio in the higher-pressure column, 1.03 bar, and a 1.8 reflux ratio in the lower pressure column, adjusting the reflux ratios to 1.75 in the higher-pressure column and 1.8 in the lower pressure column. This steam reduction, in addition to reducing operating costs, also makes the process safer by lowering pressure. Another significant factor is the potential for reduced pollutant generation caused by fossil fuel combustion and the generation of carbon credits.