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

Abstract

Extraction by using supercritical CO2 has been extensively developed to extract materials that are easily decomposed at high temperatures. Therefore, in this study extraction of valuable compounds (such as: carotenoids and fatty acids) from macroalgae of Eucheuma cottonii and Gracilaria sp was carried out experimentally with supercritical CO2 and mathematical model of Broken and Intact Cells (BIC) and Chrastil model. The result with BIC model is compared with the experimental result that has been done. Extraction was conducted at various pressures of 15, 20, and 25 MPa, temperature of 40, 60, and 80 ºC, CO2 flow rate of 6 mL/min, and ethanol concentrations for cosolvent of 5 %, 7.5%, and 10% CO2 flow rate. The content of extract was analyzed by using a Spectrophotometer UV - Vis and HPLC. The total yield of extract on Eucheuma cottonii was about 0.01623-0.03752 gr extract/gr sample at operating conditions 15 MPa pressure, temperature 60 ºC, and ethanol flow rate of 10%. The total yield of the extract on Gracilaria sp was 0.1982-0.4237 gr extract/gr samples, at operating conditions 15 MPa pressure, 60 ºC temperature, and ethanol flow rate 7.5% CO2 flow rate. The solubility of Eucheuma cottonii are greater than Gracilaria Sp with constant of Chrastil k, a, and b that are: 2,52; 0,911; and-27,66 at operating conditions. Broken and Intact Cells model could also describe well for extraction yield. The best fitting parameters in BIC model depends on condition at extraction process, such as : 0.45 – 0.46 for f, 0.5 - 0.75 for Xc, and 0.15 - 0.4 for K value..