Rigorous Modeling and Industrial-Scalable Optimization of Hydroquinone-Catechol Vacuum Distillation: Aspen Plus-RSM...

Area of Science:

• Chemical Engineering
• Separation Processes
• Process Optimization

Background:

• Conventional hydroquinone (HQ) and catechol (CAT) purification methods face challenges with high energy consumption and low efficiency.
• The thermal sensitivity and nonazeotropic behavior of HQ and CAT present opportunities for improved separation techniques.

Purpose of the Study:

• To computationally investigate and optimize vacuum distillation for efficient HQ and CAT purification.
• To identify optimal operating conditions that minimize energy consumption while maximizing product purity and recovery.

Main Methods:

• Utilized Aspen Plus for a systematic computational investigation of vacuum distillation.
• Developed an accurate thermodynamic framework using the NRTL activity coefficient model, calibrated with UNIFAC and Aspen database parameters.
• Performed rigorous vapor-liquid equilibrium and mass transfer simulations using the RadFrac module, followed by single-factor analysis, RSM, and multiobjective optimization.

Main Results:

• Identified optimal operating conditions: 10 kPa pressure, 16 theoretical plates, 11th-tray feed, 3.143 reflux ratio, and 0.092 D/F ratio.
• Achieved high product purity (99.2% HQ, 99% CAT) and recovery (98.5% HQ, 97.8% CAT).
• Reduced core distillation energy consumption by 23.7% (23.2% for the full process) compared to the industrial baseline.

Conclusions:

• The optimized vacuum distillation process offers a highly efficient and energy-saving method for HQ and CAT purification.
• Computational modeling and optimization are effective tools for enhancing industrial chemical separation processes.