Optimization study of pressure-swing distillation for the separation process of a maximum-boiling azeotropic system of water-ethylenediamine

Abstract

The separation of ethylenediamine (EDA) from aqueous solution is a challenging problem because its mixture forms an azeotrope. Pressure-swing distillation (PSD) as a method of separating azeotropic mixture were investingated. For a maximum-boiling azeotropic system, pressure change does not greatly affect the azeotropic composition of the system. However, the feasibility of using PSD was still analyzed through process simulation. Experimental vaporliquid equilibrium data of water-EDA system was studied to predict the suitability of thermodynamic model to be applied. This study performed an optimization of design parameters for each distillation column. Different combinations of operating pressures for the low-and high-pressure columns were used for each PSD simulation case. After the most efficient operating pressures were identified, two column configurations, low-high (LP+HP) and high-low (HP+ LP) pressure column configuration, were further compared. Heat integration was applied to PSD system to reduce low and high temperature utility consumption.

Alternative integrated distillation strategies for the purification of acetonitrile from ethanol ammoxidation

“…The separation of the simple binary CH3CN-Water mixture can be achieved by resolving the azeotrope through a differential pressure system [13]. The operating pressure indeed affects the composition of the azeotrope, allowing a straightforward separation [8,9,13,[18][19][20]. For instance, pressure swing has been compared by Cao et al as for costs and control options, also adopting a variable diameter column [21] and different feed temperature [22], for the following azeotropic mixtures: acetone-chloroform, acetone-methanol, methanol-chloroform, benzene-cyclohexane and isopropyl alcohol-diisopropyl ether.…”

Improved Design of Maximum-Boiling Phenol/Cyclohexanone Separation with Experimentally Verified Vapor–Liquid Equilibrium Behaviors

“…A recent review paper on extractive distillation also supported the above statement by surveying extractive distillation papers in the open literature and found out that the mixtures to be separated are rarely maximum-boiling azeotropes. Perhaps the most studied maximum-boiling system was for acetone and chloroform separation via either pressure-swing distillation or extractive distillation systems. − Other studied systems include ethylenediamine and water separation, − methanol and trimethylsilane separation, , acetic acid and N , N -dimethylacetamine separation, and some esters (methyl acetate, ethyl acetate, or vinyl acetate) and chloroform separation. − Another particular system is for the n -heptane and isobutanol separation, which exhibited minimum- and maximum-boiling azeotropes at different operating pressures …”

Optimization of Pressure-Swing Distillation for Anhydrous Ethanol Purification by the Simulated Annealing Algorithm

“…PSD has attracted special attention from researchers because it has the great advantage of not requiring any additional solvent to be introduced into the process. Due to this advantage, PSD is often mentioned as an alternative method to generally applied azeotropic or extractive distillation (Fulgueras et al, 2016). The concept of PSD is based on the fact that component mixing needs to exhibit sensitivity to pressure variation, which means that a simple increase or decrease in pressure can alter the relative volatilities of the components of the mixture with close boiling points or form an azeotrope (Kumar et al, 2010).…”