Experimental Procedure for Measuring Solid–Liquid–Gas Equilibrium in Carbon Dioxide + Solute

Abstract

The aim of this work is to report an experimental procedure for measuring solid−liquid−gas phase equilibrium behavior for binary systems constituted by carbon dioxide + solute. Our proposed measuring procedure depends on solid formation detection from fluid phases by a pressure change. The experimental apparatus uses a stainless steel cell where windows are not required. The mixture is slowly cooled while temperature and pressure are decreasing at isochoric conditions. Therefore, the solid−liquid−gas phase equilibrium data are considered when pressure exhibits an abrupt increase while temperature is still decreasing. The studied solutes are lauric acid, myristic acid, palmitic acid, and stearic acid. Besides, additional solid−liquid−gas equilibrium data are included for the same systems using an apparatus recently reported by our working group which is based on the enhanced first freezing point technique. Experimental results are represented using the Peng−Robinson equation of state coupled to the van der Waals one-fluid mixing rules with two adjustable parameters.

Solubility Measurement, Modeling, and Thermodynamic Functions for para-Methoxyphenylacetic Acid in Pure and Mixed Organic and Aqueous Systems

“…A crystallization is the most energy-intensive and economical purification procedure, the appropriate design and optimization of the process are vital. In this purview, the solid–liquid equilibrium (SLE) data of the solute in different solvents become a prerequisite to mark the process more convenient, thereby yielding high-purity product. , SLE is an important physicochemical property that dictates the thermodynamic studies and design of a crystallization process for suitable scale-up from bench scale to commercial operations.…”

“…In this purview, the solid−liquid equilibrium (SLE) data of the solute in different solvents become a prerequisite to mark the process more convenient, thereby yielding high-purity product. 5,6 SLE is an important physicochemical property that dictates the thermodynamic studies and design of a crystallization process for suitable scale-up from bench scale to commercial operations. Therefore, with the aim to purify the para-methoxyphenylacetic acid crystals from the crude product, its solubility in various pure solvents and binary mixtures was experimentally evaluated at different temperatures from 283.15 to 323.15 K using a static equilibrium method at local atmospheric pressure.…”