ASPEN plus simulation of liquid–liquid equilibria data for the extraction of aromatics from waste tyre pyrolysis gasoline using organic and deep eutectic solvents: a comparative study (original) (raw)
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Journal of the Japan Petroleum Institute, 2009
Aromatics extraction was investigated using aqueous solution of sulfolane as the solvent phase and model gasoline, consisting of a benzene, toluene, xylene and hexane mixture, and reformate gasoline as the feed phase. Firstly, the liquid-liquid equilibrium was measured to examine the distribution coefficient and the separation selectivity of aromatics relative to hexane. The distribution coefficients and selectivities of benzene were the highest, followed by those of toluene and xylene. Increased water content of the solvent phase reduced the distribution coefficients and increased the selectivities. The measured equilibria were compared with the results estimated by the UNIFAC method. Countercurrent extraction was conducted, using a packed column with glass Rashig rings as the contactor. The solvent and feed phases were contacted as the continuous and dispersed phases, respectively, and the flow rates of both phases and the water content in the solvent phase were selected as experimental parameters to examine the yield, separation selectivity and volumetric overall mass transfer coefficient. The selectivities for benzene were the highest, followed by toluene and xylene. In the case of extraction from the reformate gasoline with 9 wt％ water content in the solvent phase, the selectivity for benzene was approximately equal to 20, showing higher selectivities for aromatic components. The volumetric overall mass transfer coefficients were mainly affected by the flow rate of the continuous phase and the mass transfer resistance in the continuous phase was the controlling factor in the overall mass transfer resistance.
Computer Aided Chemical Engineering, 2007
Extractive distillation is widely used technology for recovering aromatics from different feedstock. This study investigates the recovery of aromatics which has an important commercial application such as benzene, toluene and xylenes from pyrolysis gasoline using a solvent called N-methylpyrolidone. The study also examines the procedures involved in implementing the energy-integrated extractive distillation technologies such as Petlyuk column, divided wall column and heat integrated extractive distillation column compared to conventional extractive distillation technique for processing petrochemical cuts in the range of C 5 to C 9 . Design, modeling and simulation have been conducted for the examined extractive distillation configurations and the optimum design is selected based on minimum total annual cost as the objective function. Different solvent (S)/feed (F) ratios (2/2.5/3 vol%) have been investigated to reach the optimum separating ratio, the effect of solvent feed temperature is considered also. The designed extractive distillation columns meet all expectations regarding energy consumption and cuts purity. The economic analysis proved that heat-integrated configurations are the best candidates compared to Petlyuk column and divided-wall column. Solvent feed ratio of 2 vol % found to be the best from energy and material consumption point of view, reducing solvent temperature is improving extraction process and reducing the reflux ratio of extractive column. 2 F. Abushwireb et. al
Fuel Processing Technology, 2019
This work proposes the use of the extractive distillation with ionic liquids (ILs) for the separation of aromatics from pyrolysis gasoline to overcome liquid-liquid extraction limitations. Among all the ILs proved so far, 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][TCM]) stands as the most promising in the extractive distillation of aromatics due to its high and compensate aromatic/aliphatic selectivities and aromatic distribution ratios, high thermal stability, and low viscosity. The separation of benzene, toluene, and xylene (BTX) from a pyrolysis gasoline model was experimentally investigated to check the real suitability of the [emim][TCM] for extractive distillation. A shortcut model, Fenske-Underwood-Gilliland-Kirkbride (FUGK) model, was used to simulate the extractive distillation column. A shortcut simulation of the flash distillation unit destined to separate the BTX from the IL was also accomplished. On the other hand, the quantum chemical-based simulation methodology (COSMO-based/Aspen Plus) was used to simulate the extractive distillation process rigorously. Overall, homogeneous extractive distillation with [emim][TCM] was revealed as a feasible and potential process to separate BTX from pyrolysis gasoline, showing an enhanced technology in comparison with the widely studied liquid-liquid extraction.
Journal of Chemical & Engineering Data, 2003
Liquid-liquid equilibrium (LLE) data for the systems heptane + o-xylene + tetraethylene glycol (TTEG) have been experimentally studied over the temperature range (293 to 313) K. The experimental data of this work, in addition to 22 isothermal sets of LLE data (from the literature) for the extraction of aromatics from hydrocarbon mixtures using TTEG, are analyzed using two models. The models used are the empirical Othmer-Tobias correlation and the thermodynamic UNIQUAC model as programmed in the Aspen Plus simulator. For each data set, the analysis performed by the Othmer-Tobias correlation involves the determination of the model's parameters by regressing each set of data. The predictive capability of the UNIQUAC model has been investigated in terms of deviations for the mole fraction of the target aromatic species in the extract phase. Direct fitting of the data of this work using the Othmer-Tobias model gives an average rms (root-mean-square) of 0.002 in TTEG mass fraction in the extract phase, whereas prediction using UNIQUAC gives an average rms of 0.15.
Selective Aromatics extraction from hydrocarbon mixtures
This work is aimed at the study of liquid-liquid equilibrium of systems of industrial interest, particularly the purification of oil and gas in the oil refining industry. We present experimental results on the solubility of aromatics in the liquid-liquid equilibrium obtained by gas -liquid chromatography at different temperatures. We used a mixture of solvents to improve the characteristics of selectivity and aromatics extraction. The solvent is a binary mixture of N-methyl 2-pyrrolidone (NMP) and diethylene glycol (DEG). The results presented are for two mixtures consisting of 90% NMP + 10% DEG, and 70% NMP +30% DEG. Heptane was used as hydrocarbon solvent and toluene as aromatic compound. Furthermore, we applied the equation of state NRTL (Non Random Two Liquids) and UNIQUAC (Universal Quasi Chemical) for coexistence curves and the critical point.
Separations
Green Deep Eutectic Solvents (DESs) are considered here as an alternative to conventional organic solvents and ionic liquids (IL) for the extraction of phenolic compounds from pyrolysis oil. Although ionic liquids have shown a promising future in extraction processes, DESs possess not only most of their remarkable physico-chemical properties, but are also cheaper, easier to prepare and non-toxic, increasing the infatuation with these new moieties to the detriment of ionic liquids. In this work, phenol was selected as a representative of phenolic compounds, and toluene and heptane were used to model the pyrolysis oil. COSMO-RS was used to investigate the interaction between the considered Dess, phenol, n-heptane, and toluene. Two DESs (one ammonium and one phosphonium based) were subsequently used for experimental liquid–liquid extraction. A ternary liquid–liquid equilibrium (LLE) experiment was conducted with different feed concentrations of phenol ranging from 5 to 25 wt% in model ...
Journal of Chemical Technology & Biotechnology, 2019
BACKGROUNDDeep eutectic solvents (DESs) are being used in different applications as replacements for classical organic solvents; their physico‐chemical properties comply with the criteria of environmental acceptability.RESULTSIn this work, choline chloride‐glycerol based DESs of different molar ratios (ChCl‐Gly 1:1.5, 1:2 and 1:3) were prepared and characterized with respect to density, dynamic viscosity, refractive index, electrical conductivity and thermal properties. The DESs were tested for denitrification, desulfurization and dearomatization of the six‐component model gasoline composed of three aliphatic hydrocarbons and pyridine, thiophene and toluene as representatives of nitrogen, sulfur and aromatic compounds of fuel, respectively. It was found that ChCl‐Gly is a better solvent for removal of pyridine from model gasoline in comparison with thiophene and toluene. Optimally, denitrification efficiency of 58% can be achieved in one‐stage extraction, and deep denitrification ca...
Two tricyanomethanide-based ionic liquids (ILs), namely 1-ethyl-3-methylimidazolium 14 tricyanomethanide ([C 2 C 1 im][TCM]) and 1-butyl-4-methylpyridinium tricyanomethanide ([4-15 C 4 C 1 py][TCM]) have been recently reported as effective solvents for the BTX extractive 16 distillation from pyrolysis gasoline. The vapor-liquid or vapor-liquid-liquid equilibria 17 (VLE/VLLE) of several {aliphatic + aromatic + [TCM]-based ILs} ternary systems related to 18 pyrolysis gasoline was extensively determined by headspace-gas chromatography (HS-GC), on 19 a wide range of temperatures and solvent-to-feed (S/F) ratios. The Cubic Plus Association 20 Equation of State (CPA EoS) was used to predictively describe the experimental VLE/VLLE 21 from binary interaction parameters regressed from {hydrocarbon + IL} binary systems. Here, 22 the VLE/VLLE related to the separation of the pyrolysis gasoline key components (n-octane 23 and benzene) and other aliphatic/aromatic challenging mixtures in terms of aliphatic/aromatic 24 relative volatility is reported. Specifically, the VLE/VLLE data for {n-octane + benzene + IL}, 25 {n-heptane + benzene + IL} and {n-octane + toluene + IL} ternary systems were determined. 26 The CPA EoS accuracy, robustness, and transferability between different systems is verified, 27 with the advantages and limitations shown in previous works. Overall, the results obtained in 28 this work lay the foundation for the implementation of the CPA EoS parametrization in a 29 commercial simulator to rigorously simulate the multicomponent BTX extractive distillation 30 from pyrolysis gasoline with ILs.
Fuel Processing Technology, 2015
In Europe and Japan, benzene, toluene, and xylenes (BTX) are usually obtained by liquid-liquid extraction from pyrolysis gasolines using organic solvents such as sulfolane. In the last few years, ionic liquids (ILs) have been studied as potential substitutes of conventional solvents in the extraction of BTX from alkanes. In this paper, we have studied the dearomatization of pyrolysis gasolines obtained by mild and severe cracking using the binary IL mixture composed of the 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][Tf 2 N]) and the 1-ethyl-3methylimidazolium dicyanamide ([emim][DCA]) and also employing sulfolane to compare the performance of both extraction solvents. To choose the most appropriate conditions of temperature and solvent to feed ratio to perform the extraction of BTX from pyrolysis gasolines, several extractive properties have been estimated from the experimental results employing the IL mixture and sulfolane. Simulations of countercurrent extraction columns in the dearomatization of both pyrolysis gasolines have also been made using the Kremser equation. The dearomatization of pyrolysis gasolines by the {[4empy][Tf 2 N] + [emim][DCA]} IL mixture would require a higher number of equilibrium stages in the extractor than that employing sulfolane. By contrast, the purity of extracted aromatics would be substantially greater using the IL-based solvent, simplifying the subsequent purification of the BTX.