The Solubility of Salicylic Acid in Supercritical Carbon Dioxide

Abstract

The possibility of using the method of supercritical fluid extraction for purifying the product of synthesis of salicylic acid is revealed and confirmed experimentally. A continuous-flow experimental setup is used to investigate the solubility of salicylic acid and phenol in supercritical CO 2 and to purify the product of synthesis of salicylic acid at a temperature of 308 K in the pressure range from 7.8 to 12 MPa. The salicylic acid content of the resultant product conforms to the requirements of the State Pharmacopoeia.

Measurement and Correlation of Solubility of Methylsalicylic Acid Isomers in Supercritical Carbon Dioxide

“…The correlation results are shown in Figure , and the average correlation deviations for experimental data at temperature about 308 K and all available data in the literature with respect to the MST model are summarized in Table . As shown in Table and Figure , the results from our measurements at 308.2 K and those from the extant literature ,− in a temperature range of 308–328.15 K are consistent with each other. The solubility data from different sources are in better agreement with each other for CO 2 density greater than 500 kg/m 3 but deviate from each other for density lower than 500 kg/m 3 , indicating that it is more challenging to measure solubility at the region of lower CO 2 density.…”

“…Solubility of salicylic acid in ScCO 2 from this work (red ●: 308.2 K) and literature (□: 308.15 K, ◇: 308.15 K, △: 308 K, ×: 308 K, ▽: 308 K).…”

“…In order to validate the reliability of the experimental apparatus and measurement procedure, the solubility of salicylic acid at 308.2 K was measured and compared to those reported in the literature. ,− Table summarizes the solubility of salicylic acid measured in this work; the corresponding SD and coefficient of variation (CV) of these measurements are given as well. As illustrated in Figure , the newly measured data are in satisfactory agreement with previous measurements from five different studies.…”

“…In this study, a semiflow type apparatus was constructed to investigate the solubility of three MSA isomers, 3-MSA, 4-MSA, and 5-MSA, in ScCO 2 within a pressure range of 9–18.5 MPa and a temperature range of 308.2–328.2 K. The solubility data on these three solutes have not been previously reported in the relevant literature and are investigated herein for the first time. The solubility of salicylic acid in ScCO 2 at 308.2 K was measured and compared with those reported in the literature using a dynamic apparatus ,− or a static recirculation apparatus , to validate the reliability of the experimental apparatus and procedure. The newly measured solubility data on three MSA isomers were then correlated by four semiempirical models and confirmed to pass simple consistency tests.…”

Solvation of salicylic acid in pure, methanol-modified and water-modified supercritical carbon dioxide: Molecular dynamics simulation

“…During the last decades, numerous experimental works on solubility of salicylic acid in pure and modified with polar co-solvents supercritical carbon dioxide (sc-CO 2 ) have been carried out [1][2][3][4][5][6][7][8][9][10][11][12]. Only few works were devoted to simulation of more complex fluid mixtures containing salicylic acid [13][14][15], in which little attention was paid to molecular aggregation phenomena, such as cluster formation, while solvation mechanisms were not investigated at all.…”