ENERGy EFFICIENCy OF THE COMPLEX COLUMN FOR THE SEPARATION OF VAPOR CRACkING PRODUCTS UNDER THE DEPENDING ON FEED COMPOSITION

Abstract

The dependence of the energy consumption decrease on the different feed composition for the separation of C4+ vapor cracking fraction by means of complex columns implementation is investigated. Distillation sequences consisting of simple columns and partially thermally coupled distillation columns are compared. Cases of direct and indirect separation for all the schemes are considered. In order to reduce capital cost and industrial areas the implementation of dividing wall columns was proposed. These dividing wall columns are the thermodynamic analogs of partially thermally coupled distillation flowsheets. Analysis of temperature, liquid and vapor profiles in the partially thermally coupled distillation sequence revealed that only one column in the original flowsheets requires a structural change when converting it to the partially thermally coupled configuration. It is shown that the complex columns provide energy consumption reduction in the reboilers by 3-60% as compared to conventional distillation schemes.

Keywords

• vapor cracking
• distillation
• energy saving
• complex column