Universal Quasichemical Models Research Articles

Modeling of experimental excess molar enthalpy with Wilson, UNIQUAC, and NRTL for mixtures of acetophenone with chloro derivatives of ethane and ethene at T = 298.15 K

The excess molar enthalpy HmE, was determined for systems consisting of acetophenone with chloro alkanes and alkenes derivatives. These derivatives include 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethene and tetrachloroethene at a temperature of T = 298.15 K. The Redlich-Kister relation fitting was used to analyze the HmE values obtained from this experimental data. Additionally, the excess partial molar enthalpy HiE was derived from the experimental HmE values. The intermolecular interaction function such as ∂HiE∂xi and ∂HjE∂xjwere also calculated. For the system consisting of acetophenone + 1,1,1-trichloroethane or + tetrachloroethene, the HmE values were found to be positive. Conversely, the HmE values for acetophenone + 1,2-dichloroethane or + 1,1,2,2- tetrachloroethane or + trichloroethene were observed to be negative. The magnitude of the HmE values increased in chloroethanes as the number of chlorine atoms increased, and became more negative in chloroethenes. Based on the local composition theory, the Wilson model, the universal quasichemical (UNIQUAC) model, and the non-random two-liquid (NRTL) model were used to correlate these thermodynamic data. The results showed good agreement with the experimental enthalpy data.

Harnessing dimethyl ether with ultra-low-grade heat for scaling-resistant brine concentration and fractional crystallization

Solvent-driven separations may enable scalable concentration of hypersaline brines, supporting a circular resource economy from the extraction of lithium and rare earth elements from spent battery and magnet leachates. This work analyses a novel solvent-driven water extraction (SDWE) system employing dimethyl ether (DME) and ultra-low-grade heat for brine concentration and fractional crystallization. SDWE exploits DME’s unique properties: (1) a low dielectric constant that promotes water solubility over charged solutes by a factor of 103, and (2) a high volatility that facilitate efficient DME reconcentration with ultra-low-grade heat. The techno-economic viability of SDWE is assessed with a computational framework that encompasses a liquid–liquid separator and a solvent concentrator. We integrate the extended universal quasichemical model with the virial equation of state to predict the compositions of the complex three-phase DME-water mixture at vapor–liquid and liquid–liquid equilibrium. Subsequently, we optimize the thermodynamic and economic performance of SDWE, by controlling the interstage flash pressure, heat source temperature, and the number of concentrating stages. DME-based SDWE concentrates an input saline feed to 5.5 M and regenerates over 99 % of the DME using ultra-low-grade heat below 50 °C, with a DME/water selectivity ratio of 125. Our calculations reveal that optimal performance is achieved at interstage flash pressures of 0.4 – 0.5 bar for heat source temperatures between 323–373 K, with improved exergetic efficiencies at lower temperatures. At a heat source temperature of 323 K and an interstage pressure of 0.489 bar, DME-driven SDWE achieves an optimal thermodynamic efficiency of 20.5 % and a projected specific cost of US$ 1.93 m−3. These specific costs suggest that SDWE is competitive with commercialized thermal distillation technologies, while mitigating the traditional risks associated with scaling in heat and mass exchangers with hypersaline brines.

Vapor-Liquid Equilibrium Measurement of Systems Containing Glycerol for Separation Process of Glycerol as a By-Product of Biodiesel

The most popular technique to produce biodiesel were uses alcohol as a catalyst to transesterify triglycerides. The biodiesel transesterification process has a by-product in the form of glycerol which has a high selling value. Equilibrium data of glycerol and alcohol mixtures is limited in equilibrium conditions and systems which causes the glycerol purification process may not be designed and operated optimally. This research aims to obtain experimentally isobaric vapor-liquid equilibrium of methanol + glycerol binary system at 31.3, 61.3, and 100.8 kPa. A modified Glass Othmer-Still was utilised to carry out the experiment. Refractometer index type Bausch and Lomb ABBE was used to examine the equilibrium composition of the liquid and vapor phases. Using the L-W thermodynamic consistency test method, the experimental data used in this work were shown to be thermodynamically consistent. The experimental data were correlated well with the Wilson, Non-Random Two Liquid (NRTL), and Universal Quasi-Chemical (UNIQUAC) models with absolute average deviation in temperatures (AADT) and that in vapor compositions (AADy) smaller than 0.3% and 0.2%, respectively. The Universal Chemical Functional Group Activity Coefficient (UNIFAC) in predicting VLE the system studied showed good performance giving AADT and AADy smaller than 7.4% and 0.04%, respectively.

In-depth analysis of the acetylcholinesterase inhibitors of Ganoderma amboinense based receptor-ligand affinity coupled with complex chromatography

Given the abundance and intricate nature of the chemical components found in natural food ingredients, functional food research has long grappled with two significant technical challenges: rapid and precise screening of active substances and targeted preparation. This study outlines a novel methodology to enhance the efficiency of preparing natural products, presenting new extraction processes, biological activity screening, and the preparation of acetylcholinesterase inhibitors from Ganoderma amboinense. acetylcholinesterase inhibitors were rapidly screened using ultrafiltration coupled with liquid chromatography and mass spectrometry. The inhibitory effect of active compounds on acetylcholinesterase was investigated via enzymatic reaction kinetics, with the mechanism also explored. Additionally, molecular docking and molecular dynamics simulations were used to verify the anti-alzheimer's disease activity of active compounds. Following this, the biological activity of ligands identified were separated and purified using complex chromatography (consecutive-CCC and semi-preparative HPLC). We used n-hexane: ethyl acetate: methanol: water (4.0:6.0:4.0:6.0, v/v/v/v), which optimized by a universal quasichemical functional group activity coefficient-based mathematical model and semi-preparative HPLC, 25–60% A (0–50 min), 60–100% A (50–60 min). Twelve active ingredients viz. ganoderic acids I, C2, G, B, K, A, D, F, J, ganoderenic acid A, deacetyl ganoderic acid F, and lucidenic acid F with the binding affinity for AChE were identified and isolated from natural foods. We enhance the efficiency and purity of active compounds preparation by incorporating enzyme inhibition assays and computerized virtual screening with compound chromatography. With this approach, we seamlessly incorporate fast discovery, screening, and focused preparation of active ingredients, as well as delving into the mechanisms of action of active monomers and proteases, and the molecular-level interactions between active ingredients and proteases. This approach effectively mitigates the occurrence of false positives attributable to a single technique, thereby providing valuable data to underpin future advances in enzyme inhibitor screening and isolation.

On the symmetrical and unsymmetrical reference state for ionic liquids modeling: Electrolytes versus neutral compounds

The symmetrical and unsymmetrical conventions for the reference state of the activity coefficients was applied to the Pitzer-Debye-Hückel (PDH) equation to describe long-distance interactions coupled with the UNIversal QUAsi-Chemical (UNIQUAC) model to describe short-distance interactions in binary temperature-composition (T, x) data. Based on the results of a previous work related to the closest approach parameter (ρ), in the PDH equation, a novel methodology was refined in order to obtain a more accurate description of the behavior of ionic liquids (ILs) in water. The aim of this work is to step further in a modern methodology that considers ILs as charged compounds, i.e., species that dissociate, while accounting for this dissociation extent. This study intends to set the groundwork for powerful and valuable tools for the scientific community in the field of chemistry, geology, material science, medicine, biochemistry, as well as in many engineering areas, such as chemical, biochemical, electrical and petroleum engineering.

Predicting the degree of dissociation of ionic liquids in binary mixtures with PDH+UNIQUAC

The interest in ionic liquids (ILs) as replacements for more hazardous solvents has been growing over the last years, especially in industrial synthesis and liquid-liquid separations. Consequently, it is important to study their degree of dissociation (α), which quantifies the ratio of IL molecules dissociated into their ions and significantly influences viscosity, density, and surface tension. In this work, the dissociation degree of ILs in binary mixtures was predicted based on liquid-liquid equilibria (LLE) data. To do so, the UNIversal QUAsi-Chemical (UNIQUAC) model, which describes short-range interactions, was combined with the Pitzer-Debye-Hückel (PDH) equation, which accounts for long-range interactions. In total, 31 systems comprising 15 different ionic liquids and 4 solvents (water, ethanol, 1-propanol and 1-butanol) were studied. The degree of dissociation as function of the systems' composition was determined by thermodynamic modelling and the results presented a low deviation from the experimental data available in literature, validating this novel approach.

Liquid-liquid equilibria of the ternary systems water + C1 – C3 alcohols + dimethyl adipate at 298.15 K and atmospheric pressure: Experimental data and modeling

The aim of this study was to examine the possibility of using a green organic solvent, dimethyl adipate (DMA), as a separation agent in the extraction of different alcohols from aqueous solutions. For that purpose, the liquid–liquid equilibria (LLE) of four ternary systems were analytically determined at 298.15 K and atmospheric pressure using stirred and thermo-regulated cells: {water + methanol + dimethyl adipate (DMA)}, {water + ethanol + DMA}, {water + 1-propanol + DMA}, {water + 2-propanol + DMA}. Phase diagrams for these four ternary systems were obtained by determining a binodal curve and tie-lines data using a visual cloud-point method, but also gas chromatography. Distribution coefficients and separation factors were calculated for the immiscibility region. Hand and Othmer-Tobias correlations were used to examine the reliability of the tie-line data. In addition, the experimental ternary LLE data were correlated with the UNIversal QUAsiChemical (UNIQUAC) activity coefficient models. The obtained results showed that DMA is a suitable candidate for the extraction of methanol, ethanol, 1-propanol, and 2-propanol from water. With some alcohols, this potential is more noticeable than with others. The potential of DMA as a separation agent is increasing in the following sequence: methanol < ethanol < 2-propanol < 1-propanol, and that also could be noticed from the selectivity values that also increase in this sequence. The UNIQUAC model proved as successful in correlating the LLE data.

Modeling and simulation of pervaporation (PV) separation for alcohol dehydration

The separation performance of commercial crosslinked poly (vinyl alcohol) (PVA) membranes (i.e., the new commercial membrane PERVAP™ 4100 H F and standard membrane PERVAP™ 4100) used for the dehydration of two alcohol-water systems (i.e., ethanol-water and isopropanol-water mixtures, with an azeotropic point) were studied based on pervaporation process (PV) experimental data and mathematical modeling. Pervaporation process experiments proved that these two membranes have excellent applicability for the dehydration of alcohol. A semi-empirical solution-diffusion transport model was developed to describe the mass transport in the PVA membranes, which showed a good agreement with the experimental values. The universal quasi-chemical (UNIQUAC) model was utilized to predict the activity coefficient of nonideal alcohol-water systems in PVA membranes. In addition to the UNIQUAC model, the transport of alcohol-water across the commercial polymeric membrane was modeled using the conventional driving force model. The PV process experimental data with the mathematical model were used to develop the diffusivity correlations for water and alcohol (i.e., ethanol and isopropanol) through the PVA membranes. It was found that for swollen membranes (PVA), the developed correlations of water and alcohol diffusivity were strongly influenced by the feed water activity and feed temperature. Based on the mass transport model and developed diffusivity correlations, the permeation flux of water and alcohol through the PVA membranes was predicted, and the results showed a good agreement between the experimental data and the predictive model. The mean relative errors estimated for the permeate mass fluxes of water were 8.4%, and 3.8%, and for the permeate mass fluxes of ethanol were 18%, and 13.6% for the PERVAP™ 4100 and 4100 H F, respectively, as well as for the IPA-water-PVA system are as follows: 5% and 2.8% for the permeate mass fluxes of water and 14.4%, and 12.6% for the permeate mass fluxes of IPA for the PERVAP™ 4100 and 4100 H F, respectively.

Isobaric Vapor-Liquid Equilibrium Data for Tetrahydrofuran + Acetic Acid and Tetrahydrofuran + Trichloroethylene Mixtures.

Vapor-liquid equilibrium (VLE) data for the binary systems tetrahydrofuran (THF) + acetic acid (AA) and THF + trichloroethylene (TCE) were measured under isobaric conditions using an ebulliometer. The boiling temperatures for the systems (THF + AA/THF + TCE) are reported for 13/15 compositions and five/six different pressures ranging from 50.2/60.0 to 101.1/101.3 kPa, respectively. The THF + AA system shows simple phase behavior with no azeotrope formation. The THF + TCE system does not exhibit azeotrope formation but seems to have a pinch point close to the pure end of TCE. The nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models were used to accurately fit the binary (PTx) data. Both models were able to fit the binary VLE data satisfactorily. However, the NRTL model was found to be slightly better than UNIQUAC model in fitting the VLE data for both systems. The results can be used for designing liquid-liquid extraction and distillation processes involving mixtures of THF, AA, and TCE.

Biological Buffer Effect on Liquid–Liquid Equilibria of Systems Containing n-Butanol + Methyl Isobutyl Ketone + Water

Biofuel, that is, n-butanol, production from plant-based biomass represents a renewable energy resource that can be a substitute for fossil fuel. Thus, it is important to study the separation of n-butanol from its aqueous solution to obtain a high-purity product. Liquid–liquid extraction is a beneficial process in alcohol production to recover alcohol from the aqueous medium. Liquid–liquid equilibrium (LLE) data are needed for rational design and optimal separation operation, such as biological separation and extraction processes. The objective of this study is to determine LLE data for quaternary systems of n-butanol, methyl isobutyl ketone (MIBK), water, and a biological buffer at 303.15 K and atmospheric pressure (P = 0.1 MPa). The effect of biological buffer addition into aqueous solution was also studied. Three different biological buffers, 4-(2-hydroxyethyl)-1-piperazine propanesulfonic acid (EPPS), 4-morpholinepropanesulfonic acid (MOPS), and 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), were applied in this study for the comparison. The separation factor and distribution coefficient were evaluated in this study to interpret the extraction performance of n-butanol. According to the experimental results, the extraction performance was in the order of HEPES > EPPS > MOPS, describing the strength of buffering-out as well. Furthermore, it was found that the aid of a biological buffer in the LLE systems consisting of n-butanol, MIBK, and water resulted in better extraction performance than that of the LLE systems in the absence of a biological buffer. The reliability of the experimental LLE tie-line data was satisfactorily ascertained by the Hand correlation. The non-random two-liquid and universal quasi-chemical thermodynamics models correlated well the experimental LLE tie-line data with the root mean square deviation of less than 1%. The binary interaction parameters of both models were also obtained in this study.

Predicting the ionicity of ionic liquids in binary mixtures based on solubility data

Ionic liquids (ILs) are ionic compounds which are liquid at room temperature and pressure, and can be applied in many fields, such as industrial synthesis, catalysis, electrochemistry, and liquid-liquid separations. To enhance the description of mixtures containing ILs and, consequently, to allow a more rigorous evaluation of the feasibility of chemical processes, it is important to study properties such as the ionicity (α) of ionic liquids, i.e., the fraction of dissociated molecules. However, experimental determinations of ionicity (also known as dissociation degree or dissociation extent) are time-consuming and require the handling of expensive equipment, so the prediction of this property as a function of the system's composition using thermodynamic modelling is of great relevance. For that purpose, the UNIversal QUAsi-Chemical (UNIQUAC) model was combined with the Pitzer-Debye-Hückel (PDH) equation, which is often referred as PDH+UNIQUAC, and it was used to predict the ionicity of ILs in binary mixtures based on liquid-liquid equilibria (LLE) data. The results were compared with the available experimental data from literature and low deviations were observed, validating thereafter the developed approach. In total, the IL ionicity was predicted, as function of composition, for fourteen ionic liquid / solvent (water or 1-butanol) binary systems. Further, a sensitivity analysis was performed to evaluate the influence of the LLE uncertainties on ionicity (α), and it was concluded that α was not significantly affected by small deviations, for which the methodology proposed in this work was considered robust. The prediction of IL ionicity with composition using PDH+UNIQUAC thermodynamic modelling was considered a breakthrough, since very accurate results were achieved without the need of undergoing complex experiments.

Measurement and correlation of liquid-liquid equilibrium for the ternary system (water + 1,2-dichloroethane + sulfolane) at 288.15, 298.15, and 308.15 K

Sulfolane is an important aprotic polar solvent. Liquid-liquid equilibrium (LLE) data for the ternary systems of water + 1,2-dichloroethane + sulfolane were measured at temperatures of 288.15, 298.15 and 308.15 K under the atmospheric pressure. The distribution coefficient and selectivity were determined from the measured LLE data, which showed that 1,2-dichloroethane is a suitable extractant for the recovery of sulfolane from its aqueous solution. The nonrandom two-liquid (NRTL) model and the universal quasi-chemical (UNIQUAC) model were utilized to correlate the experimental LLE data. The low values of RMSD indicated that the ternary system could be fitted well by the NRTL and UNIQUAC models. The consistency of the binary interaction parameters for the two thermodynamic models obtained was confirmed by the topological information contained in the Gibbs energy of mixing function ( G M / RT ).

Analysis of the rectifying separation of H2 O–D2 O mixture into light and heavy water by means of mathematical modeling

Objectives. To apply an analytical method for the calculation of a distillation column for the production of D2O at a two-column Kuhn installation operating under vacuum: to simulate the Kuhn installation in the Hysys software; and to compare experimental and calculated data.Methods. Analytical method for the calculation of distillation columns “from stage to stage,” from the lower theoretical separation stage (TSS) to the upper stage. This method is based on phase equilibrium at the TSS with known data of input flows and component concentrations in the column bottoms. Hysys was used as modeling software.Results. Comparison of the calculation results with Kuhn’s experimental data testified to the high calculation accuracy of the vapor–liquid phase equilibrium for the H2O–D2O mixture at the TSS. The convergence of the D2O material balance for the entire installation was 0.005%. The identification parameter was the number of the column feed plate. Simulation of the Kuhn installation in the Hysys software showed a qualitative agreement of D2O concentrations in material flows. The UNIQUAC (UNIversal QUAsiChemical) model was used to calculate activity coefficients. The found values of the number of theoretical separation stages (NTSS) in both columns, were 88 and 153 taking into account the reboiler and condenser. This is less than the experimental 295 and 400, respectively. The discrepancy can be explained by the increased phase equilibrium H2O constant in the UNIQUAC model. However, the convergence of the material balance in terms of D2O was high and amounted to 1.38·10−6 %. The absolute error of the found concentrations in material flows did not exceed 0.12 mol %.Conclusions. The results obtained indicated the possible use of the Hysys modeling software when searching for and optimizing the operating mode of the block diagram of a cascade of distillation columns with direct and recycle flows to separate a mixture of water into light and heavy water. The final results obtained with regard to the operating mode, inlet and outlet material flows (flow rate, composition, temperature, and pressure drop across the column) are recommended for use in the analytical program for the calculation of the distillation column to refine the NTSS and distribution profile of the concentrations of the H2O and D2O components along the height of the column.

Vapor-Liquid Equilibrium (VLE) Curve for Furfural Purification from Oil Palm Empty Fruit Bunch Hydrolysate Solution with the UNIQUAC Model

Furfural is the main Oil Palm Empty Fruit Bunch (OPEFB) hydrolysis product. It can achieve high purity from hydrolysate distillation. Its equipment design can be done by utilizing vapor-liquid equilibrium (VLE) data to achieve high furfural purity. The purpose of this research is to develop a Vapor-Liquid Equilibrium (VLE) curve for furfural purification from Oil Palm Empty Bunch hydrolysate solution with the Universal Quasi Chemical (UNIQUAC) model. Distillation data is obtained from literature and examined on the Universal Quasi Chemical (UNIQUAC) model. Calculations for average deviation and R2 are also made to show the accuracy of the model quantitatively. The modeled VLE curve indicates that the UNIQUAC model and the literature distillation pattern are not ideal, and the UNIQUAC curve pattern closely follows the literature pattern. The average deviation and R2 values for this UNIQUAC model are 0.0954 and 0.297, respectively. These values are still acceptable and show that UNIQUAC can be used as useful model distillation data of furfural and water as the representatives of an OPEFB hydrolysate solution.

Calculating the closest approach parameter for ethyl lactate-based ATPS

Aqueous Two-Phase Systems (ATPS) is a powerful separation technique for biotechnological compounds, such as pigments, proteins and flavonoids. Nowadays, ATPS generally include dissolved salts, which cause phase immiscibility and promote solute partition. Therefore, to accurately model the liquid-liquid equilibria (LLE) of these systems, specific terms for the long-range interactions in thermodynamic models are needed. A well-known hypothesis for this purpose is the Pitzer-Debye-Hückel (PDH) term, which requires the knowledge of the closest approach parameter (ρ), i.e., an adjustable parameter. The aim of this work was calculating this parameter supposing total dissociation of the salts in ethyl lactate-based ATPS. In this new approach, ρ became specific for each chemical species and its physical meaning (related to the distance between ions of different charges) was preserved. This method was applied in the LLE modelling of 7 ethyl lactate + organic or inorganic salts + water systems measured by the group, using the PDH term coupled with the UNIversal QUAsi-Chemical (UNIQUAC) model, whose junction is generally known as PDH+UNIQUAC, and compared with classical UNIQUAC and with previous works. The new approach accurately described the experimental liquid-liquid equilibria (LLE) data and presented smaller composition deviations than UNIQUAC.

Determining the dissociation extent of ionic liquids in water using the PDH + UNIQUAC model

The main goal of this work was to find a novel way of qualitatively determining the dissociation extent of ionic liquids (ILs) in water, based only on thermodynamic models. The UNIversal QUAsi-Chemical (UNIQUAC) model was applied separately (to account for short-range interactions and considering only neutral molecules) and coupled with the Pitzer-Debye-Hückel (PDH) equation (to account for long-range interactions) to binary temperature-composition data (Txx). For calculating the closest approach parameter (ρ), which appears in the PDH equation, a new method was developed considering the ionic radii and solvation. This novel strategy, which considers that ILs may dissociate and accounts for the dissociation extent, allows the description of systems containing these compounds more accurately, which is a very useful tool for both academia and industry.

Design Optimization of Deep Eutectic Solvent Composition and Separation Performance of Cyclohexane and Benzene Mixtures with Extractive Distillation

Deep eutectic solvents (DESs) have properties that make them suitable candidates to be used as entrainers for extractive distillation. In the previous work, it was proven that DES(1:2) (tetrabutylammonium bromide: levulinic acid, 1:2, molar ratio) can break the cyclohexane-benzene azeotrope. In the present work, the HBA and HBD ratio and molar concentration of DES were optimized to obtain a better constitute and condition of DES to be utilized in cyclohexane and benzene extractive distillation. The physical properties and structure of the prepared DESs were characterized. Vapor–liquid equilibrium data of the ternary system (benzene + cyclohexane + DESs) were also measured at atmospheric pressure. All experimental equilibrium data were correlated with Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) activity coefficient models, from which the coefficient of determination (R2) of the three pseudo-ternary systems fitting was calculated. From the obtained results, the best HBA and HBD ratio in the DESs is elucidated as 1:2, the best molar concentration of DES is 0.1, and the NRTL model predicts the experimental data more accurately than the Wilson and UNIQUAC models. From the derived mechanism, the formation of stronger hydrogen bond and π–π bond interactions between DES and benzene is obtained when HBA and HBD ratio in DES is 1:2. In other conditions, the azeotrope cannot be broken, or the efficiency is low. The present work provides an environmentally friendly method to separate aromatic/aliphatic mixtures and act as a guide for further study of DESs in extractive distillation.

A solvent deasphalting dearomatization (SD-A2) process for heavy oil upgradation

A two stage solvent deasphalting dearomatization (SD-A2) process has been conceptualized for upgrading heavy oils. In the first stage, pentane, heptane and refinery untreated/ treated naphtha streams (Light Naphtha (LN), Heavy Naphtha (HN) & Raffinate Naphtha (RN)) were investigated for deasphalting performance. To enhance the deasphalting, spent catalyst from Fluid Catalytic Cracking Unit (FCCU) is used in the first stage which showed increase deasphalted oil (DAO) and also pitch yields up to 2 wt%. In the second stage, six polar solvents viz. sulfolane, N-methylpyrrolidone (NMP), tri-ethylene glycol, tetra-ethylene glycol, furfural and N-formylmorpholine (NFM) have been analyzed for dearomatization. The phase equilibria behaviour of these six potential polar solvents was investigated, including the interaction behaviour of their components with heavy oil components using ternary phase diagrams at ambient conditions, before selecting the most suitable solvent for dearomatization. Based on the phase equilibria data, distribution coefficient, selectivity, and performance index (PI) of the solvents was also estimated. For the oils which have C6–C15 carbon range, the universal quasi-chemical UNIQAC model was used to predict the liquid–liquid equilibria (LLE) and solvent NMP gave highest performance index for the high carbon number feedstock. The effects of solvent types and solvent to feed ratio on the deasphalting performance was also investigated. Finally, the DAO obtained at each stage was fed to a fluid catalytic cracking (FCC) bench-scale unit and the results showed significant improvement in gasoline yields up to 5 wt% and the coke was also lowered to 2 wt%.

Experimental measurements for the liquid-liquid equilibrium of ternary systems [(water + methyl oleate + model mixtures of tar (naphthalene, phenanthrene and anthracene)] issued from the biomass gasification process

Energy, fuel and chemical production like syngas from biomass is increasingly attracting interest in the world, with increasing potential to replace conventional fossil fuels in the energy market.Biomass gasification has been studied widely as an efficient and sustainable technology for the syngas production.Thus, raw syngas contains a significant quantities of undesirable impurities known as syngas contaminants, especially tar which can cause major problems to the gasification process; therefore it is crucial to eliminate the generated tar in this process by one of the most promising method “the tar scrubbing oil” using a suitable extracting solvent. With this aim, an experimental study of the liquid–liquid equilibrium of the ternary systems of water + solvent (methyl oleate-biodiesel solvent) + model mixtures of tar (naphthalene, phenanthrene and anthracene) that are presented in the raw syngas was conducted at 303.2 K, 323.2 K and 343.2 K. Due to the low solubility of the studied model molecule of tars in the aqueous phase, an extraction of these analytes (naphthalene, phenanthrene and anthracene) from the aqueous phase was performed by an auxiliary solvent (dichloromethane), in which was dissolved an internal standard (hexadecane) before analysis in the GC–MS using the internal standard technique. A control analysis was systematically performed in order to ensure that all of the solute was extracted from the aqueous phase. As for the analysis of the organic phase, it was carried out in the GC–MS using the internal standard technique without any prior extraction. Coulometric Karl Fischer (KF) titration was used to quantify water in the organic phase. Partition coefficient and selectivity of the biodiesel solvent were also discussed. This work is followed by a modeling study of the same systems using the nonrandom two-liquid (NRTL) and UNIQUAC (universal quasichemical) models.

Application of deep neural network (DNN) for experimental liquid-liquid equilibrium data of water + butyric acid + 5-methyl-2-hexanone ternary systems

LLE data are important for simulation and design of extraction equipment. In this study, deep neural network (DNN) structure was proposed for modelling of the ternary liquid-liquid equilibrium (LLE). LLE data of (water + butyric acid + 5-methyl-2-hexanone) ternaries defined at three different temperatures of 298.2, 308.2, and 318.2 K and P = 101.3 kPa, were obtained experimentally and then correlated with nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) models. The performance of the proposed DNN model was compared with that of NRTL and UNIQUAC in terms of the root mean square errors (RMSE). RMSE values were obtained between 0.02-0.06 for NRTL and UNIQUAC, respectively. For DNN, the error values were obtained between 0.00005-0.01 for all temperatures. According to the calculated RMSE values, it was shown that proposed DNN structure can be better choice for the modelling of LLE system. Othmer-Tobias and Hand correlations were also used for the experimental tie-lines. Distribution coefficient and separation factors were calculated from the experimental data.