Thermal coupling links to liquid‐only transfer streams: An enumeration method for new FTC dividing wall columns

Abstract

Novel dividing wall columns (DWCs) can be obtained by converting thermal couplings to liquid-only transfer streams. Here, we develop a simple four-step method to generate a complete set of DWCs containing n 2 2 dividing walls, for a given n-component fully thermally coupled (FTC) distillation. Among the novel DWCs, some easy-to-operate DWCs possess the property that the vapor flow in every section of the DWC can be controlled during operation by means that are external to the column. We develop a simple method to enumerate all such easy-to-operate DWCs. We expect that the easy-to-operate DWCs can be operated close-to-optimality; leading to a successful industrial implementation of the n-component (n ! 3) FTC distillation in the form of a DWC. As an illustration, we show figures of all easy-to-operate DWCs with two dividing walls for the four-component FTC distillation.

Classification and Comparison of Dividing Walls for Distillation Columns

“…These two configurations are thermodynamically equivalent to the column configurations shown in Figure 1l,n respectively. These two column configurations are section rearrangement versions of the FTC configuration along with the conversion of one of the two-way thermal coupling into Agrawal's liquid-only transfer(ALT) [16,24] and hence thermodynamically equivalent to the FTC configuration [13,[25][26][27].…”

“…Kaibel used the DWC depicted in Figure 1a to represent Brugma's quaternary column configurations [14,15]. Later in a series of publications, Madenoor Ramapriya, Tawarmalani and Agrawal (MTA) introduced a systematic method to draw DWC versions for any given thermally coupled column configuration [7,16,17]. Here a thermal coupling refers to a two-way vapor liquid mass transfer between the two columns.…”

Optimal Design, Proportional-Integral, and Model Predictive Control of Intensified Process for Formic Acid Production II: Reactive Dividing Wall Column without Uncontrollable Vapor Split

“…Also they clarified that the new derived arrangement is thermodynamically equivalent to the original one under minimum vapor flow conditions. Then the idea was extended to various thermally coupled configurations used for multicomponent separation. − Cui et al conducted optimization for 10 configurations for ternary mixtures, which also contained the structures modified from the side rectifier and stripper using the same strategy. Recently, multiloop control structures were developed and tested for the modified Peltyuk column with a liquid-only transfer stream .…”

Easy-to-Operate and Energy-Efficient Four-Product Dividing Wall Columns with Two Partition Walls

“…In this way, configurations with a vapor split regulated by a method outside the column and configurations without a vapor split could be derived. The the idea was extended to a fully thermally coupled arrangement for FPDWCs (initially proposed by Sargent, which is referred as the Sargent configuration ,, in the following section), and the number of new configurations has been enumerated in recent work. , The complex Sargent configuration is characterized by a complex structure with three independent partition walls and 13 column sections incorporated in its corresponding DWC configuration, but its energy efficiency is regarded as the highest among these FPDWCs with various structures. Furthermore, the above-mentioned strategy was expanded to any thermally coupled columns derived from the distillation column sequence, by extending the partition wall continuously to the ends of the column to make the FPDWCs easy to operate. , However, the following issues are not covered in the above-mentioned work: first, the easy-to-operate configuration is only thermodynamic equivalent to the original one with an uncontrollable vapor split under minimum vapor flow conditions.…”

“…The the idea was extended to a fully thermally coupled arrangement for FPDWCs (initially proposed by Sargent, which is referred as the Sargent configuration 12,23,24 in the following section), and the number of new configurations has been enumerated in recent work. 25,26 The complex Sargent configuration is characterized by a complex structure with three independent partition walls and 13 column sections incorporated in its corresponding DWC configuration, but its energy efficiency is regarded as the highest among these FPDWCs with various structures. Furthermore, the above-mentioned strategy was expanded to any thermally coupled columns derived from the distillation column sequence, by extending the partition wall continuously to the ends of the column to make the FPDWCs easy to operate.…”