Correlation of Mass Transfer Coefficients in Supercritical CO₂ Separation Process

Abstract

Weighted least squares and error-in-variable statistical methods were used to minimize variations in the experimental data set obtained from literature, and were used to validate Models I and II, S h′ = 0.0015(R e ^1/2 S c ^1/3)^2.58 and S h′ = 0.00084(R e ^0.4299 S c ^0.8783), respectively. Published data were used for the empirical estimation of mass transfer coefficients in separation processes in fixed bed systems using supercritical carbon dioxide extraction with low molecular diffusion. Model I gained accuracy when the Schmidt Number Sc is high (> 70) and the molecular diffusion is weak. The exponential ratio of the Re and Sc of Model II differed from the common ratio of 3:2; however, the exponents of the Sc are unique for both Models I and II.

Keywords:

• Dimensionless numbers
• Essential oils
• Extraction
• Mass transfer
• Supercritical carbon dioxide

ACKNOWLEDGEMENT

The authors gratefully acknowledge the contribution of the Guelph Food Research Program, Agriculture and Agri-Food Canada (AAFC Journal Series No. S 199).