2006 Fiscal Year Final Research Report Summary
Analysis of complex entrainer effect on extraction of natural products with supercritical fluids
| Project/Area Number |
16560660
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Properties in chemical engineering process/Transfer operation/Unit operation
|
|---|
| Research Institution | KYUSHU UNIVERCITY |
|---|
Principal Investigator |
IWAI Yoshio Kyushu University, Faculty of Engineering, Associate Professor, 大学院工学研究院, 助教授 (80176528)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YONEZAWA Setsuko Kyushu University, Faculty of Engineering, Research Associate, 大学院工学研究院, 助手 (50294898)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Keywords | Entrainer effect / Ethanol / Water / Solubility / Supercritical carbon dioxide / Caffeine / Extraction / Interaction |
|---|
| Research Abstract |
The solubilities of caffeine in supercritical carbon dioxide, supercritical carbon dioxide + water, supercritical carbon dioxide + ethanol and supercritical carbon dioxide + water + ethanol were measured by a static circulation method with an on-line FT-IR spectroscopy at 313.2 K and 15.0 MPa. The solubility of caffeine on a mole fraction basis increase 22 % by the addition of saturated water, and becomes 5 times by the addition of 1000 mol m^<-3> of ethanol. However, the solubilities of caffeine in supercritical carbon dioxide + water + ethanol are smaller than those in supercritical carbon dioxide with the same concentrations of single entrainer (water or ethanol).
The peaks of the C=O stretching bands for caffeine were changed with increasing the concentrations of ethanol. The C=O stretching band of caffeine interacting with ethanol appeared at lower wavenumber than the C=O stretching band of free caffeine by deconvolution of the C=O stretching band in supercritical carbon dioxide + caffeine + ethanol system. It was found that C(2)=O group is easier to interact with ethanol than C(6)=O group. The concentrations of free caffeine and interacting caffeine with ethanol can be expressed by interaction equilibrium constants. The equilibrium constants were applied to the solubilities of caffeine in supercritical carbon dioxide + ethanol. The concentrations of free caffeine gradually decrease with increasing the concentration of ethanol and approach to a constant value. The enhancement of solubility for caffeine in supercritical carbon dioxide by the addition of ethanol is due to the hydrogen bonding between caffeine and ethanol.
|
