Optimization and upscaling of the supercritical carbon dioxide extraction of Solidago gigantea Ait. of an industrial relevance

Abstract

The main aim of this study was to investigate the possibility of using Solidago gigantea Ait., as a source of fatty acids. S. gigantea, by contrast to rapeseed or sunflower seeds, is not commonly used plant material to obtain these compounds. For that purpose, the proper optimization of supercritical carbon dioxide extraction (SFE-scCO2) of S. gigantea at quarter-technical plant was investigated to provide the highest concentration of FAME. SFE-scCO2 is a green technology and it is very efficient technique for the extraction of non-polar compounds. Response surface methodology (RSM) was used to analyze and evaluate the influence of chosen input variables: pressure (P, MPa), temperature (T, K) and solvent flow rate (F, kg h−1) on FAME content in products. The output variable in the obtained extract was determined by GC–MS. The optimal parameters obtained at quarter-technical plant were T =313.79 K (40.64 °C), P = 22.22 MPa and F =6.46 kg h−1. Finally, the scale-up procedure of optimal conditions from the quarter-technical to half-technical plant was conducted to substantiate the correctness of the optimization process and to facilitate the transfer of the process to industry scale. Scale-up procedure of optimal conditions was conducted according to various criteria and it ended successfully. Extraction with constant ratio of solvent mass to mass of the batch (S CO2/M, kg kg−1) with the final result with confidence interval: 273.22 mg g−1 DM proved the correctness of the optimization proces. The obtained amount of FAME concentrations allowed to conclude that S. gigantea can be considered as a source of fatty acids. Finally, obtained optimal parameters can be implemented in an industry plant.