Simulation and heat integration optimization of the separation process for high-value-added products from C₉⁺ heavy aromatic hydrocarbons

Objective Flexible regulation of high-value product yields and reduction of energy consumption are targeted to be achieved in the separation process of reformed C₉⁺ heavy aromatic hydrocarbons through process optimization.

Method Based on the comparative analysis of conventional four-tower separation and three-tower separation processes, the optimal process was determined, followed by optimization of key operational parameters and thermal integration design.

Result The four-tower separation multiple component process was completed based on adding solvent separation tower in three-tower separation single component process. And the aromatic solvents SA-1000 and SA-1500 was producted simultaneously with all prodcution qaulity indexes meeting the requirements and achieving the flexible adjustment recovery of SA-1000 in the range of 17.8%−47.8%. The best operation conditions of solvent separation based on flexibility analysis were as follows: tower top pressure of 50 kPa; total tower tray number of 41; feed position was the 19th tray; and minimum reflux ratio of 3.62. Through thermal integration optimization between the heavy component removal tower and the solvent separation tower, the total heat consumption was reduced by 11.79%.

Conclusion The optimized four-tower multi-component separation process was verified to enable high-efficiency, low-energy consumption separation of C₉⁺ heavy aromatics, providing a practical reference for industrial applications aimed at producing high-value-added products.