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  • Recovering value from organic waste materials: Supercritical fluid extraction of oil from industrial grape seeds
    Publication . Coelho, Jose; Filipe, Rui; Robalo, Maria Paula; Stateva, Roumiana P.
    Supercritical extraction of oil from grape seed samples obtained from a Portuguese industry was carried out at temperatures from (313-333) K, pressures up to 40.0 MPa and different scCO(2) flow rates. The qualitative analysis of the crude oil was carried out by NMR. The fatty acids were analyzed by GC-Fid with reference to the parameters in Annex I to European Commission Regulation. The results show similar content of TAGs and DAGs both in the n-hexane and scCO(2) extraction methods, but the latter have higher PUPA and lower saturated fatty acids content. A dynamic model was used to simulate the extraction curves in gPROMS ModelBuilder. The grape seed oil was represented as either a one or a three component mixture of triacylglycerols, and the deviation between the experimental and calculated extraction yields was in the range (2-9) % for the first, and (4-11) % for the second case.
  • Modelling the kinetics of supercritical CO2 extraction of biomass
    Publication . R. M. Filipe; Coelho, Jose; Robalo, Maria Paula; Cholakov, Georgi; Stateva, R. P.
    This work addresses the modelling and simulation of the kinetics of CO2 supercritical extraction of oils from biomass. Experimental and simulation results from different matrices and models are presented. gPROMS Model Builder is used to find solutions to three different models applied to study the extraction of three different volatile oils from aromatic plants (coriander, fennel and savoury), and from a bioresidue, industrial grape seeds. The supercritical extraction experiments performed at different temperature, pressure and flow rate conditions provide the data to the modelling studies and for model parameter estimation. The qualitative and quantitative agreement between the experimental and simulated extraction profiles in terms of yields was good for the cases investigated.