Multicomponent phase equilibria of an extra-virgin olive oil in supercritical carbon dioxide

Simulation of Organic Liquid Product Deoxygenation through Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Process Modeling and Simulation

In this work, the deoxygenation of organic liquid products (OLP) obtained through the thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na₂CO₃ as a catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO₂) as a solvent, with an Aspen-HYSYS process simulator, was systematically investigated. In a previous study, the thermodynamic data basis and EOS modeling necessary to simulate the deoxygenation of OLP was presented. This work addresses a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 pressure pump, and 02 make-ups of CO₂, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and that the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95 and 92.78% (wt.) on a solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenated compounds with concentrations of up to 32.66% (wt.) on a solvent-free basis, showing that the organic liquid products (OLP) were deacidified and SC-CO₂ was able to deacidify the OLP and obtain fractions with lower olefin contents. The best deacidifying condition was obtained at 333 K, 140 bar, and (S/F) = 17.

Simulation of Organic Liquid Products Deoxygenation by Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Thermodynamic Data Basis and EOS Modeling

In this work, the thermodynamic data basis and equation of state (EOS) modeling necessary to simulate the fractionation of organic liquid products (OLP), a liquid reaction product obtained by thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na₂CO₃ as catalyst, in multistage countercurrent absorber/stripping columns using supercritical carbon dioxide (SC-CO₂) as solvent, with Aspen-HYSYS was systematically investigated. The chemical composition of OLP was used to predict the density (ρ), boiling temperature (T_b), critical temperature (T_c), critical pressure (P_c), critical volume (V_c), and acentric factor (ω) of all the compounds present in OLP by applying the group contribution methods of Marrero-Gani, Han-Peng, Marrero-Pardillo, Constantinou-Gani, Joback and Reid, and Vetere. The RK-Aspen EOS used as thermodynamic fluid package, applied to correlate the experimental phase equilibrium data of binary systems OLP-_i/CO₂ available in the literature. The group contribution methods selected based on the lowest relative average deviation by computing T_b, T_c, P_c, V_c, and ω. For n-alkanes, the method of Marrero-Gani selected for the prediction of T_c, P_c and V_c, and that of Han-Peng for ω. For alkenes, the method of Marrero-Gani selected for the prediction of T_b and T_c, Marrero-Pardillo for P_c and V_c, and Han-Peng for ω. For unsubstituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of T_b, Marrero-Gani for T_c, Joback for P_c and V_c, and the undirected method of Vetere for ω. For substituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of T_b and P_c, Marrero-Gani for T_c and V_c, and the undirected method of Vetere for ω. For aromatic hydrocarbon, the method of Joback selected for the prediction of T_b, Constantinou-Gani for T_c and V_c, Marrero-Gani for P_c, and the undirected method of Vetere for ω. The regressions show that RK-Aspen EOS was able to describe the experimental phase equilibrium data for all the binary pairs undecane-CO₂, tetradecane-CO₂, pentadecane-CO₂, hexadecane-CO₂, octadecane-CO₂, palmitic acid-CO₂, and oleic acid-CO₂, showing average absolute deviation for the liquid phase (AADx) between 0.8% and 1.25% and average absolute deviation for the gaseous phase (AADy) between 0.01% to 0.66%.

Supercritical carbon dioxide extraction of astaxanthin from Haematococcus pluvialis with vegetable oils as co-solvent

Soybean oil and olive oil were investigated as continuous co-solvents for supercritical carbon dioxide (SC-CO(2)) extraction of astaxanthin from Haematococcus pluvialis. Without co-solvents, only 25.40+/-0.79% efficiency was achieved with SC-CO(2) extraction at 70 degrees C and 40 MPa at a continuous flow rate of 3 mL min(-1) for 5h. In the presence of soybean oil or olive oil as a co-solvent, the extraction efficiency was enhanced, with the most appropriate level of soybean oil in the solvent mixture being 10% by volume. At this concentration and the above extraction conditions, the highest extraction efficiency of 36.36+/-0.79% was obtained for soybean oil, a 30% increase in extraction efficiency compared with SC-CO(2) extraction without soybean oil, whereas the 10% olive oil increased the extraction efficiency further to 51.03+/-1.08%, which was comparable to that obtained using ethanol as co-solvent.

Supercritical CO2 extraction of oilseeds: review of kinetic and equilibrium models

Mass transfer models on supercritical carbon dioxide (SC-CO2) extraction of vegetable oils are reviewed, that may facilitate the scale-up of laboratory data for industrial design purposes. Reviewed mechanisms of oil transport within the solid matrix include the desorption from the solid, the formation of a shrinking core of condensed oil in a non-adsorbing porous matrix, and diffusion in a homogenous medium. Analyzed simplificat ions of a general mass transfer model include external control of mass transfer rates, internal control of mass transfer rates, consideration of a linear driving force, and steady state approximations, among others. More complex two-stage models, and critical comparisons of some of the proposed models are also included. Trends for the external mass transfer coefficient and effective diffusivity in the solid matrix from studies on SC-CO2 extraction of oil from vegetable substrates are thoroughly discussed and contrasted with those obtained using simpler model systems. The possible effect of the axial dispersion on the rate of extraction is also discussed. Finally, the high-pressure vegetable oil-CO2 phase equilibrium is discussed in connection with its influence on the mass transfer process. Special emphasis is given to the role of the solid matrix on high-pressure phase equilibrium.