Mechanical design and hydrodynamic analysis of sieve trays in a dividing wall column for a hydrocarbon mixture

Abstract

Distillation is one of the most widely used separation processes, mainly because it allows obtaining products with high purities. However, it has high energy requirements due to its low thermodynamic efficiency. Among the alternatives to reduce these energy requirements, the dividing wall column (DWC) is one of the most promising technologies, also allowing savings in capital costs compared to conventional distillation sequences. Even so, there is only little information about the physical design of dividing wall columns, and most of the recent developments on this area have been achieved by private industry. Moreover, most of the reported information is for packed columns. Nevertheless, the design of dividing wall columns with trays is important for systems with high vapor loads. Thus, a strategy for the mechanical design of sieve trays for the separation of a hydrocarbon mixture in a dividing wall column is presented in this work. Furthermore, an operational analysis of the trays using Computational Fluid Dynamics (CFD) is reported. Designed trays are tested in terms of weir flooding, active zone flooding and flow regime. Reported strategy allows obtaining operational designs for the trays of the whole column.