Extraction and isolation of indole alkaloids from Tabernaemontana catharinensis A.DC: Technical and economical analysis

In the present work, the technical and economical analysis of extraction and isolation of indole alkaloids from Tabernaemontana catharinensis is presented. The extraction was carried out using supercritical CO2 as solvent and ethanol as cosolvent (5%, v/v). The global yield isotherms were determined at 35 and 45 °C for pressures of 150–350 bar. The mass transfer rate for the constant extraction rate period (CER), the duration of the CER period, and the mass ratio of solute in the fluid phase at the bed outlet were calculated. The extraction curves were adjusted by Crank, Goto et al. and Esquível et al. models. The economical analysis was carried out considering that the cost of manufacturing can be obtained in terms of the costs of investment, operational labor, raw material, waste treatment and utilities. The higher global yields were obtained at 350 bar (1.30 × 10−2 and 1.54 × 10−2 kg/kg, at temperatures of 35 and 45 °C, respectively). The Goto's model was able to quantitatively describe the experimental data. The cost of manufacturing the extracts obtained at 350 bar, 45 °C, using 5% (v/v) of ethanol was US$ 79.35 kg−1 of extract. Using previous experimental data obtained at 300 bar, 55 °C, using 10% of ethanol (v/v), the cost of manufacturing for the fractionation process to obtain a rich alkaloidal fraction (AF) was US$ 440.31 kg−1 of alkaloids.