Simultaneous Extraction and Separation Process for Coffee Beans with Supercritical CO₂ and Water

Abstract

The aim of this work was to develop a new process for extraction and separation of polar and nonpolar compounds from natural materials using supercritical CO2 (SCCO2) in water. In this work, chlorogenic acid and caffeine from coffee beans were used as model compounds of polar and nonpolar compounds, respectively. Extraction and separation were conducted in three types of semicontinuous extractors with different sizes and flow types of CO2 and water. The effect of temperature and pressure in the separation mode using SCCO2 in flow and water in batch mode has been reported. Recovery of caffeine in the SCCO2 phase increased with decreasing temperature and increasing pressure. However, only the increasing pressure could promote the increasing recovery of caffeine and chlorogenic acid in water phases. The change of height of the nonpolar recovery section on the recovery of caffeine and chlorogenic acid in SCCO2 and water phases and on the separation factor has been studied using SCCO2 and water in co-current and counter-current flow modes. Recovery of caffeine and separation factor of caffeine from chlorogenic acid significantly increased with increasing height of nonpolar recovery section. The effect of temperature in counter-current type of separation on the recovery of caffeine and chlorogenic acid in SCCO2 and water phases exhibited different trend with batch type of separation. The counter-current type of separation was more effective compared to both batch and co-current types of separation. On the basis of the results of this work, it is suggested to design longer extractor columns with a higher nonpolar recovery section in the counter-current type in order to increase separation efficiency.

Recent advances in extraction and analysis procedures of natural chlorogenic acids

“…Azevedo et al (2008) showed that the addition of ethanol and isopropyl alcohol as co-solvents increases the yield of CQAs from green coffee beans. Experiments of Machmudah et al (2011) revealed that not only the addition of a polar solvent but also the way of conducting the extraction affects the yield. These researchers proved that the counter-current extraction in flow mode is more effective compared to both batch and co-current extraction with CO 2 .…”

Mathematical modeling of supercritical CO2 extraction of valuable compounds from Eucheuma Cottonii and Gracilaria Sp

“…Afterwards, the role of ethanol was investigated, tempting the different percentages those are: 5; 7.5; and 10%, with CO 2 flow rate of 6 ml/min.. In this research, the results of pressure, temperature, and supercritical CO 2 flow rate of two macro algae on extraction yield were examined, and the experimental and model results were compared [11]. Table 1 and table 2 show the experimental data that were compared with the model of broken and intact cells.…”

Design of a Cost‐Reduced Flexible Plant for Supercritical Fluid‐Assisted Applications

“…Traditional solid‐liquid extraction requires the use of expensive and hazardous organic solvents, harmful both for living beings and the environment . Supercritical CO 2 extraction overcomes this obstacle providing high‐quality extracts while reducing the toxicity associated with the solvents and shortening the processing time .…”