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

Abstract

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 (Tb), critical temperature (Tc), critical pressure (Pc), critical volume (Vc), 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 Tb, Tc, Pc, Vc, and ω. For n-alkanes, the method of Marrero-Gani selected for the prediction of Tc, Pc and Vc, and that of Han-Peng for ω. For alkenes, the method of Marrero-Gani selected for the prediction of Tb and Tc, Marrero-Pardillo for Pc and Vc, and Han-Peng for ω. For unsubstituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb, Marrero-Gani for Tc, Joback for Pc and Vc, and the undirected method of Vetere for ω. For substituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb and Pc, Marrero-Gani for Tc and Vc, and the undirected method of Vetere for ω. For aromatic hydrocarbon, the method of Joback selected for the prediction of Tb, Constantinou-Gani for Tc and Vc, Marrero-Gani for Pc, 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%.

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

“…hydrocarbons and 10% (area.) oxygenates, and that acidity is mainly due to the presence of carboxylic acids, OLP has been described by the key-compounds hydrocarbons (Decane, Undecane, Tetradecane, Pentadecane, Hexadecane, and Octadecane) and oxygenates (Palmitic acid, Oleic acid) [112][113]. The simulations performed by selecting the unit operation multistage countercurrent absorber, as the dissolution/solubilization of gases (CO2) in liquids (OLP) is a function of state conditions (P, T), and that a fraction of the coexisting liquid phase dissolves in the gas phase, like a gas (CO2)-liquid (OLP) equilibrium behavior.…”

“…The OLP deoxygenation process, using SC-CO2 as solvent, was simulated using Aspen- HYSYS 8.6 (Aspen One, 2015). The simulations performed by selecting the multistage countercurrent absorber/stripping unit operation because of its similarities and/or theoretical thermodynamic fundamentals of solubility of gas in liquids, as the phase equilibrium behaves like a gas-liquid coexisting phases, as described elsewhere [112][113]. Aspen-HYSYS 8.6 computes the countercurrent multistage absorber column unit operations by applying the inside-out algorithm to solve simultaneously materials and energies balances stage-to-stage coupled with a rigorous thermodynamic model.…”

“…Aspen-HYSYS 8.6 computes the countercurrent multistage absorber column unit operations by applying the inside-out algorithm to solve simultaneously materials and energies balances stage-to-stage coupled with a rigorous thermodynamic model. The RK-Aspen EOS with the adjusted binary interaction parameters was selected as fluid package to compute the mixture properties for the multicomponent mixture OLP/SC-CO2 [112][113].…”

“…al. [113] provided the thermodynamic data basis and the EOS modeling to simulate the deoxygenation of OLP obtained by thermal-catalytic cracking of palm oil at 450 °C, 1.0 atm, with 10% (wt.) Na2CO3 [17], making it possible to perform the process simulation of OLP deoxygenation by multistage countercurrent absorber with SC-CO2 as solvent using the process simulator Aspen-HYSYS.…”

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

“…hydrocarbons and 10% (area.) oxygenates, and found that acidity is mainly due to the presence of carboxylic acids, whereby OLP has been described by the key compounds of hydrocarbons ( decane , undecane , tetradecane , pentadecane , hexadecane , and octadecane ) and oxygenates ( palmitic acid , oleic acid ) [ 59 , 60 ]. The simulations were performed by selecting the unit operation multistage countercurrent absorber, as the dissolution/solubilization of gases (CO 2 ) in liquids (OLP) is a function of state conditions (P, T), whereby a fraction of the coexisting liquid phase dissolves in the gas phase, such as with a gas (CO 2 )–liquid (OLP) equilibrium behavior.…”