LEE KWANG JAE Thermodynamics and Green Processing Laboratory, Dept. of Chem. Eng., Sogang Univ.

1. 2003 추계 화공학회 / 열역학 부문 A High Pressure Fiber-Optic Reactor with Charged-Coupled Device Array Ultraviolet-Visible Spectrometer for Monitoring Chemical Processing in SCCO2 LEE KWANG JAE Thermodynamics and Green Processing Laboratory, Dept. of Chem. Eng., Sogang Univ. Thermodynamics /Green Processing Laboratory

2. Objective • A fiber-optic based reactor connected directly to a CCD array ultraviolet(UV) - visible spectrometer for in situ determination of reaction rates in supercritical carbon dioxide • To measure the solubility in a supercritical dyeing process directly • To measure dissolution rates • To obtain a absorbance data from samples Thermodynamics /Green Processing Laboratory

3. Equipment type for measurement of solubility • A Flow Type Method – Dymamic method- the simplest experimental method- being the clogging of the expansion valve due to dry ice formation- dye particle precipitation- becomes an obstacle to the correct solubility evaluation especially at high solute concentration • A Batch Type Method – Static method- hard to collect samples- need to measure a volume accurately • A Online Spectroscopic Method By Using Optical Fibers- easy to measure an absorbance- in situ observation of the phase equilibrium by VIS-spectroscopy Thermodynamics /Green Processing Laboratory

4. Theory • Beer-Lambert’s LawA = εl Cwhere, A = absorbance of sample l = path length C = concentration of sampleε = optical density • Hexane was used as the solvent for calibration because it has a polarity similar to that of CO2 and has been shown to exhibit similar extinction coefficient and negligible shifts in the position of absorption maxima Thermodynamics /Green Processing Laboratory

5. TI Heise Experimental Apparatus Optical fiber Optical fiber Magnetic stirrer UV-Vis spectrophotometer ISCO 260D

6. Specification of equipment Thermodynamics /Green Processing Laboratory

7. CN CH2CH2CN O2N N N N CH2CH2O OH O O NH2 O N O OH NH2 O Br O OH NH2 O OH Properties of materials

8. H3C CN Br OCH3 CH2CH2OCOCH3 O N N O O2N N N N N S O HO CH2CH2OCOCH3 CH3 NO2 NHCOCH3 O Properties of materials

9. Comparison of data for DR 60 Thermodynamics /Green Processing Laboratory

10. Determination of a path length Thermodynamics /Green Processing Laboratory

11. Absorbance curves for DY 54 Thermodynamics /Green Processing Laboratory

12. Determination of optical density for DY 54 Thermodynamics /Green Processing Laboratory

13. Result The Solubility data for DY 54 in SCCO2 Thermodynamics /Green Processing Laboratory

14. Conclusion and future works • We can be obtained the solubility data of dye stuffs in SCCO2 by using a in situ UV-VIS spectroscopy with optical fiber. • The path length of the optical fiber in the reactor can be changed to suit the experimental needs. For example, the path length can be increased for measuring compounds with low solubilities. • The obtained data will be correlated with empirical equation and MF-NLF equation of state. • We will measure and correlate the solubility of various disperse dyestuffs in SCCO2. Thermodynamics /Green Processing Laboratory