The Design and Optimization of Extractive Distillation for Separating the Acetone/n-Heptane Binary Azeotrope Mixture

Abstract

Acetone and n -heptane are common solvents in the pharmaceutical industry and they have been found in wastewater. Under atmospheric conditions, the mixture of these compounds creates a minimum-boiling azeotrope. The extractive distillation process with a high boiling solvent is commonly utilized to separate the azeotropes in the industry to minimize waste, reuse resources, achieve clean production, and preserve the environment. In this work, extractive distillation was applied to separate the binary azeotropic system of acetone and n -heptane in wastewater using butyl propionate as a solvent. The characteristics of the process are designed and simulated via Aspen Plus. The simulation results showed that to get a distillate containing at least 99.5 mass% acetone, a solvent-to-feed ratio of 1.4, a reflux ratio of 1.5, a number of stages of 30, a feed stage of 26, a solvent stage of 10, and a solvent temperature of 298.15 K were required. The optimum operating parameters of the process were also obtained using the NLP optimization method, with the minimum total annual cost as the objective function. While the process was operating in optimal mode, CO 2 emissions were calculated to be 0.0780 kg CO 2 /kg feed.

Multi-objective Optimization and Control of Self-Heat Recuperative Azeoropic Distillation for Separating an Ethanol/Water Mixture

“…At this time, ethanol and water will form azeotrope, which is difficult to be further purified by ordinary distillation, and thus other dehydration methods need to be used. 3,4 Azeotropic distillation, 5,6 extractive distillation, 7,8 and pressure-swing distillation 9 are all effective methods for separating azeotropic mixtures, and lots of energy-saving technologies are proposed to improve these processes. 10,11 The introduction of process intensification and integration technology in distillation can effectively reduce the energy consumption and improve the energy efficiency, such as heatintegrated distillation, 12,13 dividing-wall column distillation, 14,15 and cyclic distillation.…”

“…The mass fraction of ethanol obtained from the ordinary distillation section can reach 92.4– 94 wt %. At this time, ethanol and water will form azeotrope, which is difficult to be further purified by ordinary distillation, and thus other dehydration methods need to be used. , Azeotropic distillation, , extractive distillation, , and pressure-swing distillation are all effective methods for separating azeotropic mixtures, and lots of energy-saving technologies are proposed to improve these processes. , …”

Decrease in CO2 Emissions in Obtaining Polymer‐Grade Propylene by Extractive Distillation

“…In this way, the relative volatility of the mixture increases, favoring its separation. Therefore, the light component is obtained as a distillate product in the extractive column, while the heavy component and the solvent are got as bottom products, which are separated in the recovery column, where the heavy component is gained as a distillate product and the separating agent as a bottom product 16–18.…”

Process Simulation and Multiobjective Optimization for High-Purity Hexane Recovery Using Deep Eutectic Solvent

“…Ionic liquids (ILs) are a new type of green solvent that has been developed as an alternative to sulfolane in recent years . It has the advantages of good selectivity, strong chemical stability, and thermal stability.…”

“…5 Ionic liquids (ILs) are a new type of green solvent that has been developed as an alternative to sulfolane in recent years. 6 It has the advantages of good selectivity, strong chemical stability, and thermal stability. A series of imidazolium-based ILs have been widely studied due to their excellent physical and chemical properties, especially for their extraction capacity of aromatics removal from benzene−hexane system.…”