Liquid distributor is an important internal in packed distillation columns. One of the key features of this equipment is the drip point density, which corresponds to the number of irrigation points per area of the cross-section. For gravity liquid distributors, increasing the number of irrigation holes generally requires small hole diameters, which makes the equipment more sensitive to plugging. In this work, we disclose a new gravity liquid distributor that achieves large drip point densities without requiring smaller irrigation holes. This distributor is an adaptation of the classic orifice-pan type, in which we add a tree-like structure made of wires to spread the liquid dripping from the orifices. The liquid flows outside the wires and splits several times over the different branching levels before falling on the packed bed. From an orifice-pan configuration with drip point density of 736 pts/m2, we designed and constructed enhanced distributors with a theoretical irrigation density of 14,800 pts/m2. Performance comparison using a recently disclosed structured packing shows that these enhanced distributors can decrease HETP from 0.45 m to 0.27 m. & COPY; 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

The concept of Heat Integrated Distillation column (HIDiC) was introduced by Mah et al [1] to improve the energy efficiency of distillation processes. Firstly, a brief review of the HIDiC configurations and pilot plants is introduced. The objective of this study is to demonstrate the performance of a new packing specific for HIDiC tested in a concentric HIDiC pilot plant to prove the operability and the overall performance. First, the new specific packing and its characterization are presented. The characterization includes the hydrodynamics, the mass transfer and heat transfer performance. For the experiments on HIDiC pilot plant, several tests are performed at steady state of 90 min. One of these experiments is presented with the operating parameters (boiler heat and pressure ratio). The cyclohexane/n-heptane binary mixture is used for these experiments. The simulation results of a classical distillation column are compared to HIDiC column steady state operation. This comparison demonstrates energy savings about 40 %.

An innovative-structured packing (for distillation and absorption columns) based on cylindrical wires is 3D printed in polyamide and stainless steel. Several configurations are designed by modifying some geometrical parameters, such as the wire diameter and length. Hydrodynamic and mass transfer studies are executed on the printed structures and on a reference internal (Mellapak 250Y) to characterize their performances. These new packings show some promising results. Most of the designed configurations are characterized by a high packing capacity and a good mass transfer efficiency. Hence, these structures can be successfully implemented in a distillation or absorption column. ? 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

This paper presents accurate models evaluating the hydrodynamic and separation behavior of an innovative packing structure called Tetra Spline (TS) packing. The newly designed internal is a wire-based lattice packing fabricated via additive manufacturing for gas-liquid contact systems, such as distillation and absorption columns. Using dimensional analysis, four correlations are developed for the prediction of dry and wet pressure drops, flooding velocity, and HETP of the TS internals in a two-phase system, regardless of its physicochemical properties. The performances are modeled based on extensive experimental data described in a previous work. These data are obtained by performing hydrodynamic and mass transfer characterizations on fifteen different TS configurations. Then, some of the proposed correlations are compared to other models available in literature. The final step will highlight that after optimization of the geometrical parameters the TS packing can reach high performances. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

The concept of Heat Integrated Distillation column (HIDiC) was introduced by Mah et al. (1977) to improve the energy efficiency of distillation processes. The aim of this study is to propose a new conceptual design methodology for concentric HIDiC. Our methodology is based on simulation of the process performed on ProsimPlusTM and found the optimised heat exchange between the two parts of the process. The optimised heat exchange is characterized by the maximum of energy transmissible between the two sections, before the column does not work properly and the simulation does not run. This paper presents the three different steps to achieve the design of the concentric HIDiC for chosen operating conditions. The design procedure and the simulation are carried out for the separation of a binary mixture cyclohexane and n-heptane. In addition to presenting the design results, the energy gain was verified compared to the simulation of a classical distillation column.

Distillation is the most applied separation technology. Its major drawback is the low thermodynamic efficiency (typically around 15 %). In response to the environmental issues that concerns energy consumption of distillation column, HIDiC (heat integrated distillation column) which combines advantages of vapor recompression and diabatic operation, is expected to have a large impact on energy saving. In this study, a concentric column which contains an innovative column packing designed in LGC research lab of Toulouse is carried out. First of all, this novel technology is characterized from a heat transfer point of view in a dedicated pilot plant. Compared to the Raschig super-ring results, the heat transfer in this innovative column packing is much more efficient, with a heat transfer increase of 102 %. A second HIDiC pilot has been implemented to test the operability and the overall performances of this HIDIC technology. Different tests have been made to reach a time of steady state of 90min. Several experiments were carried out with different operating parameters (boiler heat and pressure ratio). The Cyclohexane/n-Heptane binary mixture is used for these experiments. The simulation results of a classical distillation column are compared to HIDiC column steady state operation. This comparison demonstrates an energy saving about 40 %.

In this paper, a study of kinetics effects on the reactive liquid-liquid extraction column is proposed. In a first part, design parameters of reactive liquid-liquid extraction column are derived from a method proposed by Mizzi (2016). In a second part, using a kinetic model, the performances of the column are studied with different configuration and design parameters. This study allows a comparison of the performances of the column in terms of conversion rate, recovery rate and purity. For the chosen examples, the kinetic limitation is very strong. So the unit operations of reactive liquid-liquid extraction with a high retention capacity will be privileged: a cascade of decanter mixers. In conclusion, this article shows that the choice of solvent and the parameters of the column as the solvent flowrate, the number of theoretical stage, liquid hold up or kinetics of the reaction have an important influence on the performances of the column and sometimes on the feasibility of the separation.

A general design methodology for reactive liquid–liquid extraction is introduced in this paper. It is composed of three different steps: feasibility analysis, pre-design determination and simulation validation. This paper is focused on the first and the second step. This methodology leads to the design specifications of the units from the information concerning the physico-chemical behaviour of the studied system, exploiting the equilibrium and material balance equations. The results of this methodology are a good starting point for an optimization study or for an investment calculation process. This methodology has been applied to different case studies: two different strategies of extraction and several solvents to recover succinic acid in fermentation broth.