Improving Distillation Energy Network Using High Performance Distillation Equipment

Energy costs are the largest percentage of a hydrocarbon plant’s operating expenditures. This is especially true of the distillation process which requires substantial energy consumption. Concerns over recent high costs and economic pressures continually emphasize the need for efficient distillation design and operation without a loss of performance.

As continuous distillation requires simultaneous heat input and removal (thus generating significant energy consumption), complex heat integration is becoming more common for modern distillation units to improve unit energy efficiency. Since a distillation column’s degree of separation and enthalpy balance influence each other, it is critical to evaluate and optimize the distillation column and heat exchanger networks together in order to maximize plant economics.

The paper will illustrate how energy efficient design can be applied in a distillation unit through optimization between the distillation column and heat network system. As a case study, a successful retrofit of an aromatics distillation unit will be discussed. Detailed retrofit activities including complex heat network evaluation, process simulation modeling and energy-friendly, high-performance distillation equipment implementation are described.