| Autor: |
Avdeev, Mikhail V., Konovalov, Aleksei N., Bagratashvili, Viktor. N., Popov, Vladimir K., Tsypina, Svetlana I., Sokolova, Maia, Ke, Jie, Poliakoff, Martyn |
| Zdroj: |
Physical Chemistry Chemical Physics (PCCP); 2004, Vol. 6 Issue: 6 p1258-1263, 6p |
| Abstrakt: |
A fibre optic reflectometer FOR has been developed to monitor refractive index n and density ρ changes in gases, liquids and supercritical fluids SCFs. The key operating principle is the measurement of the intensity of light from a light emitting diode, LED, which is reflected from the end of a fibre immersed in the medium. The amount of reflected light depends on the difference between the refractive indices of the fibre and the medium. The refractive index of the medium is related in turn to its density. The FOR is particularly sensitive to phase separation, a key aspect of supercritical fluid systems, because of the density discontinuity which accompanies the separation. This device allows the collection of data with a high spatial 9 μm-fibre diameter and time ∼0.02 s resolution. The small size of the fibre optic probe means that it can be put into operating reactors and even catalyst beds. Experiments are described with pure CO2and CHF3, and mixtures CO2 cyclohexane and CO2 MeOH over wide pressure and temperatures ranges. The measurements are in excellent agreement with published data for these systems. |
| Databáze: |
Supplemental Index |
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