Divided‐wall distillation column design using molecular tracking

Abstract

Divided-wall column (DWC) is an intensified separation process and so far developing a simple procedure for designing these units has been challenging. In this work, the concept of molecular tracking has been integrated with conventional methods to build a simple and easy-to-use methodology for designing DWCs for multicomponent separations. Application of the proposed approach is highlighted through several three-and four-component mixtures. The configuration obtained using molecular tracking gives a design with lower energy demands for the column reboiler, compared to other design methodology, which directly impacts the OPEX of the system.

A feasible path-based branch and bound algorithm for strongly nonconvex MINLP problems

“…From Table 2, it can be observed that the configuration obtained by using FPBB is very similar to the configuration in the literature (Montonati et al, 2022). The method used in the literature (Montonati et al, 2022) is a special procedure, which requires short-cut models to determine the initial design parameters of DWC, followed by equilibriumstaged simulation, molecular tracking application and finally using many simulations to investigate the effects of varying parameters in the flowsheet to find an optimal design. The design procedure is tailored without generality and computationally intensive for design of DWC.…”

“…These two configurations are rather different. From Table 5, we can see that the total number of trays obtained from the FPBB algorithm is 135, which is 28 more than 106 in the literature (Montonati et al, 2022). The larger number of stages results in a smaller reflux ratio and less energy consumption in both condenser and reboiler.…”

“…To illustrate the capability and superiority of the proposed FPBB algorithm, three process intensification problems (i.e., DWC) and two process synthesis problems (i.e., distillation sequences synthesis) are solved. The first two examples are taken from Montonati et al (2022) and involve the separation of ternary hydrocarbon mixtures. Example 3 requires the separation of a four-component mixture in a Kaibel column.…”

“…In the final optimal integer solution, all the bypass efficiencies are at 0 or 1. We also compare the optimal design with that from literature (Montonati et al, 2022), which is generated using the specialised or heuristic procedure. The comparative results are also provided in Table 2.…”

“…This is reflected on the prolonged CPU time and nodes generated and evaluated. The resulting configuration from the FPBB algorithm is compared with the corresponding configuration using molecular tracking from the literature (Montonati et al, 2022). The results are presented in Table 5.…”