Energy Savings in the Benzene-Toluene-Xylene Separation Process Using an Extended Divided-Wall Column

摘要

Benzene-toluene-xylene (BTX) separation is one of the processes consuming large amounts of energy in the petrochemical industry. A new BTX separation process utilizing an extended divided-wall column is proposed. Its performance with regard to energy savings and cost reduction was examined in comparison with that of the conventional BTX separation process. The energy saving of the proposed process resulted largely from the reduction of the processing load in the extraction process, which consumes large amounts of energy and high-cost steam. The design results of the proposed system indicated that 35.8% of the heating duty and 32.2% of the cooling duty were saved compared to the heat duty in the conventional process. While the investment cost of the proposed system increased by 12.6 %, the utility cost was reduced by 33.9 %. The increased investment cost can be returned by 7.5 months of operation due to utility cost reduction.