Model assisted supercritical fluid extraction and fractionation of added-value products from tobacco scrap

Residues of the tobacco industry are a source of valuable compounds such as solanesol and nicotine. In this work, the supercritical fluid extraction of these compounds from tobacco scrap was studied. The effect of the key process parameters (pressure, temperature, extraction time) was analyzed and a phenomenological model of the extraction was applied in order to derive solubility and mass transfer coefficients. Furthermore, solanesol and nicotine obtained by supercritical extraction were fractionated by means of a liquid-liquid extraction. Results show that different conditions are required depending on the purpose of the extraction: low pressure (15 MPa) in order to enhance solanesol yield and solanesol selectivity, and high pressure (37 MPa) to promote nicotine extraction, while model results indicate that the best results were obtained in conditions in which the extraction was controlled by the solubility parameters. These results provide indications for the valorization of residues produced by the tobacco industry.