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- Recovering value from organic waste materials: Supercritical fluid extraction of oil from industrial grape seedsPublication . 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 biomassPublication . 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.
- Supercritical CO2 extraction of spent coffee grounds. Influence of co-solvents and characterization of the extractsPublication . Coelho, Jose; Filipe, Rui; Robalo, M. Paula; Boyadzhieva, Stanislava; Cholakov, Georgi; Stateva, RoumianaSpent coffee grounds (SCGs) were extracted with supercritical CO2 at temperatures of 313 K and 333 K, pressures up to 50.0 MPa and different scCO(2) flow rates. The addition of co-solvents isopropanol, ethanol and ethyl lactate decreased the time to achieve the maximum oil yield, to half of that with pure CO2. Analysis of the extracted oils by NMR, showed that caffeine content was (0.56-3.96) % and DUFA and MUFA contents changed within (39.8-42.0) % and (12.9-15.8) %, respectively. The analyses of fatty acids performed by GC-FID revealed the composition of the oils being 76 % of the total constituted by palmitic and linoleic esters. The DPPH antioxidant capacity was improved up to 12.5 times with co-solvents. The kinetics of oil extraction from SCGs with pure scCO(2) was modeled successfully by combining for the first time representation of the oil mixture by a single virtual molecule with group contribution methods.
- Application of a novel approach to modelling the supercritical extraction kinetics of oil from two sets of chia seedsPublication . Villanueva Bermejo, David; Fornari, Tiziana; Calvo, Maria V.; FONTECHA, JAVIER; Coelho, Jose; Filipe, Rui; Stateva, Roumiana P.The kinetics of the supercritical fluid extraction of edible and discarded chia seeds was studied and modelled for the first time. The total oil was removed at 45 MPa and 60 degrees C after 240 min. The extraction kinetics was simulated using a dynamic model in gPROMS ModelBuilder environment and the kinetic parameters estimated. Triolein was chosen as a model compound of the chia oil. The agreement between the experimental yields and those calculated by the model was good with deviations in the range (1.2-6.6) %, except at 25 MPa and 60 degrees C (AARD = 9.5%). (C) 2019 The Korean Society of Industrial and Engineering Chemistry.