Composition Of Liquid Phase Research Articles

Heterogeneous thermodynamic comparison of the tert-butyl glycerol ether synthesis from glycerol via olefin etherification or alcohol dehydration

On the basis of the principle of Gibbs free energy minimization, a genetic algorithm was used to carry out a comparative study on the heterogeneous thermodynamics of the glycerol etherification with isobutanol, and the glycerol dehydration with tert-butanol to butyl glycerol ethers. Under the conditions in the temperature range of 40-300 °C, the pressure range of 0.1-0.7 MPa, the feed of 100 mol of glycerol + 600 mol of other reactant, the effects of temperature and pressure on the equilibrium conversions, product selectivities and gas-liquid equilibrium composition were investigated. The results show that for the etherification process, low temperature is conducive to the generation of tri-tert-butyl glycerol ether, while high temperature is conducive to the generation of di-tert-butyl glycerol ether and mono-tert-butyl glycerol ether. The elevated pressures promote the formation of tri-tert-butyl glycerol, while inhibit the production of di-tert-butyl glycerol ether and mono-tert-butyl glycerol ether. For the dehydration process, the equilibrium conversion of glycerol is close to 100%, the selectivity of tri-tert-butyl glycerol ether is more than 90%, the selectivity of di-tert-butyl glycerol ether is less than 10%, and mono-tert-butyl glycerol ether is efficiently converted. The results also show that for the dehydration process, increasing the pressure moves the heterogeneous temperature range to the right, and the liquid phase composition can be adjusted by changing the pressure.

THE STUDY OF PROPERTIES OF SODA PRODUCTION WASTES AS ANTI-ICING REAGENTS

The article considers the possibility of reducing the man-made load on surface and ground waters in Lysychansk-Severodonetsk industrial agglomeration caused by numerous sludge collectors and tailings storage facilities of various industries formed many decades ago. The paper provides information on the location and technical condition of the sludge collectors of the liquidated "LYSSODA" manufacture (Luhansk oblast), the amount of waste currently stored in them as well as the impact of these wastes on the quality of groundwater in the area where the sludge collectors are located. The work shows one of several possible options for using such wastes as a valuable secondary mineral raw material for obtaining a marketable product. The averaged data on the chemical composition of the solid phase of sludge and indicators of the liquid phase composition are given. According to the results of the analysis of scientific and technical information, it has been found that such wastes can ultimately be used for the production of anti-icing reagents. The obtained results of research on the dependence of the freezing point of working solutions on the concentration of salts, including the added corrosion inhibitors (triethanolamine, hexamethylenetetramine), indicate the feasibility of using soda ash production waste to obtain effective liquid anti-icing reagents without a mechanical component, while the optimal amount of added corrosion inhibitors is 0.5% wt. Such reagents can be used both undiluted at temperatures up to minus 20oC and strengthened to 15-20% wt. by calcium chloride at temperatures up to minus 40°C with consumption on highways at the level of about 100 g/m2 of the treated surface.

Innovative Eco-Friendly Conductive Ink Based on Carbonized Lignin for the Production of Flexible and Stretchable Bio-Sensors.

In this study, we report a novel way to produce carbon-based conductive inks for electronic and sensor technology applications. Carbonized lignin, obtained from the waste products of the Eucalyptus globulus tree paper industry, was used to produce a stable conductive ink. To this end, liquid-phase compositions were tested with different amounts of carbonized lignin powder to obtain an ink with optimal conductivity and rheological properties for different possible uses. The combination that showed the best properties, both regarding electrochemical properties and green compatibility of the materials employed, was cyclohexanone/cellulose acetate/carbonized lignin 5% (w/w), which was used to produce screen-printed electrodes. The electrodes were characterized from a structural and electrochemical point of view, resulting in an electrochemically active area of 0.1813 cm2, compared to the electrochemically active area of 0.1420 cm2 obtained by employing geometrically similar petroleum-based screen-printed electrodes and, finally, their performance was demonstrated for the quantification of uric acid, with a limit of detection of 0.3 µM, and their biocompatibility was assessed by testing it with the laccase enzyme and achieving a limit of detection of 2.01 µM for catechol as the substrate. The results suggest that the developed ink could be of great use in both sensor and electronic industries, reducing the overall ecological impact of traditionally used petroleum-based inks.

Phase Behavior Analysis of CO2 and Formation Oil System

In this paper, there are nine oil samples to explore the characteristics of formation oil at different CO2 injection rate, and the characteristics include bubble point pressure, volume expansion coefficient, viscosity, density, and average molecular weight, composition of gas and liquid phase, and asphalt sediment. According to the experimental results of early nine oil samples of swelling tests, in high temperature and high pressure conditions, characteristics and changing rules of properties of formation oil, including bubble point pressure, volume expansion coefficient, viscosity, density, and average molecular weight, composition of gas and liquid phase, and asphalt sediment, were evaluated and analyzed at different CO2 injection rate systematically. The research not only can provide guides for petroleum engineers when they need to adjust the injection and production programs, but also can provide comparatively comprehensive experimental rules for researches on enhanced oil recovery (EOR) mechanisms of gas miscible and nonmiscible flooding. Moreover, phase parameters of different formation oil system can be extracted for reservoir numerical simulation.

Kinetic analysis of the partial synthesis of artemisinin: Photooxygenation to the intermediate hydroperoxide

The price of the currently best available antimalarial treatment is driven in large part by the limited availability of its base drug compound artemisinin. One approach to reduce the artemisinin cost is to efficiently integrate the partial synthesis of artemisinin starting from its biological precursor dihydroartemisinic acid (DHAA) into the production process. The optimal design of such an integrated process is a complex task that is easier to solve through simulations studies and process modelling. In this article, we present a quantitative kinetic model for the photooxygenation of DHAA to an hydroperoxide, the essential initial step of the partial synthesis to artemisinin. The photooxygenation reactions were studied in a two-phase photo-flow reactor utilizing Taylor flow for enhanced mixing and fast gas-liquid mass transfer. A good agreement of the model and the experimental data was achieved for all combinations of photosensitizer concentration, photon flux, fluid velocity and both liquid and gas phase compositions. Deviations between simulated predictions and measurements for the amount of hydroperoxide formed are 7.1 % on average. Consequently, the identified and parameterized kinetic model is exploited to investigate different behaviors of the reactor under study. In a final step, the kinetic model is utilized to suggest attractive operating windows for future applications of the photooxygenation of DHAA exploiting reaction rates that are not affected by mass transfer limitations.

(Invited) Nitrogen Fixation Using Non Thermal Atmospheric Plasma (over water) : Challenges and Perspectives

Nitrogen fixation, i.e. the transformation of molecular nitrogen into nitrates or ammonia is a major industrial process. The Haber-Bosch and the Ostwald processes are at the origin of the massive increase of yield of food production, contributing to the development of modern agriculture. However, despite the fact that these processes are exothermic, the need to operate at high temperature for kinetic reasons, the necessity to start (most often) from natural gas as a source of hydrogen, and the industrial plants located far away from the end user, make these industrial processes huge producers of CO2.Historically, the Birkeland-Eyde process, however, allow to fix nitrogen using arc plasma. The energy yield of this process being small, it was replaced by the Haber-Bosch process. With the development of low temperature, non thermal plasmas processes, there is nowadays a hope to develop local, low energy cost, nitrogen fixation reactors, with only air as reactant. For food and agriculture applications, especially for urban agriculture, a possible approach is to generate nitrates directly inside the water that feeds the plants. The talk will present a few non thermal atmospheric plasma setups than can be used for nitrogen fixation. In a first setup, nitrogen oxides are generated directly in a dielectric barrier discharge (DBD) filled with various proportions of nitrogen and oxygen. In a second setup, one of the dielectrics is replaced by water. In a third setup, a DC microplasma is lighted up between a metallic electrode and a water solution, containing an electrolyte. In this last setup, a counter electrode closes the electrical circuit, making it resembling a electrochemical cell. In this last setup, two configurations are tested, by changing the polarity of the two electrodes.For all the setups, the amount of various nitrogen oxides formed in the gas phase as a function of the experimental parameters is studied using optical emission spectrometry, infrared spectrometry and mass spectrometry. Similarly, the composition of the liquid phase is analyzed using ionic chromatography and specific reagents tests. Correlations between a) the gas phase composition and b) the liquid phase composition are established. The role of OH radicals (in the gas phase) and hydrogen peroxide (in the liquid phase) on the relative amounts of nitrites and nitrates is evidenced. For the microplasma experiments, it is shown that inverting the polarity of the electrodes lead to drastic changes in the yields of the species produced. From all these results, potential mechanisms will be presented, and future challenges will be open to discussion.

Study on the PTX Parameters and Fractal Characteristics of Ore-Forming Fluids in the East Ore Section of the Pulang Copper Deposit, Southwest China

In this paper, the east ore section of the Pulang porphyry copper deposit is selected as the research object. The micro-thermometer and laser Raman spectroscopic technique are utilized to study the parameters of ore-forming fluids such as pressure, temperature, and compositions. In the meantime, the fractal models, including the perimeter-area (P-A) model and number-size (N-S) model, are introduced to quantify the shape of fluid inclusions, and distinguish the stages of ore-forming fluids, respectively. The results show that the types of fluid inclusions are diversified, namely two-phase liquid-rich type, two-phase vapor-rich type, three-phase CO2-rich type, three-phase halite-bearing type and pure liquid type. The fluids of main mineralization stage are characterized by medium-high temperature (170.2–421.4 °C), medium-high salinity (9.3 wt.%–33.3 wt.%), and low density (0.73–1.06 g/cm3). With the migration and evolution, the temperature, salinity, and pressure of ore-forming fluids gradually decrease, while the density of fluids increases. The liquid-phase compositions mainly include H2O, and the vapor-phase compositions consist of H2O, CH4, N2, and CO2, indicating the characteristics of reducing fluids and the mixing of atmospheric precipitation. In general, the characteristics of ore-forming fluids in the east ore section are similar to those of the first mining area, suggesting that the ore-forming fluids in the east ore section may not migrate from the first mining area. And the east ore section may be a relatively independent metallogenic system. Moreover, the fractal analysis results demonstrate that the shape of fluid inclusions formed in the same hydrothermal activity features self-similarity. The DAP values of fluid inclusions in B veins, ED veins, and D veins are 1.04, 1.06 and 1.10, respectively, showing a gradually increasing trend from the main stage to the late stage of mineralization. Meanwhile, the shape of fluid inclusions ranging from B veins to D veins becomes increasingly irregular. It also reveals that the homogenization temperature satisfies fractal distribution with four scale-invariant intervals, suggesting that all B veins, ED veins, and D veins have experienced at least four hydrothermal activities. Compared with histogram, the N-S fractal model is able to describe the distribution characteristics of the ore-forming fluids’ homogenization temperature more precisely. Therefore, it presents a potential tool for the stage division of ore-forming fluids. This research provides information about the characteristics of ore-forming fluids in the east ore section of the Pulang porphyry copper deposit, which is beneficial for further exploration in this region, and the extension of the application of fractal models in the study of fluid inclusions. However, further testing of fractal models on the fluid inclusion study is warranted to fully determine the universality.

PHASE EQUILIBRIA IN THE NaCl–CaCl2–CaO SYSTEM

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).

R1224yd(Z), R1233zd(E) and R1336mzz(Z) as replacements for R245fa: Experimental performance, interaction with lubricants and environmental impact

Achieving the 2050 EU climate targets - an economy with net-zero greenhouse gas emissions - requires a significant increase in the share of renewables in the current energy mix. The Organic Rankine Cycle (ORC) could play an important role in this transformation of today’s energy systems. The ORC is able to convert low-temperature heat sources into electrical power by utilizing refrigerants as working fluids. Many of these refrigerants have a significant global warming potential (GWP) and recent legislations therefore increasingly limit their use. In recent years a new generation of refrigerants has been developed. These refrigerants are characterized by low global warming potentials and are considered as replacements for the old high-GWP refrigerants.In this paper R1224yd(Z), R1233zd(E) and R1336mzz(Z) are investigated as possible replacements for the state of the art high-GWP refrigerant R245fa. These novel fluids have quite similar thermophysical properties and can thus potentially be used as drop-in replacements for R245fa. For the application as drop-in replacement and the correct interpretation of measurement data, the interaction of the refrigerant with the used lubricant is important. Therefore, the interaction of all four refrigerants with a typical lubricant oil is experimentally investigated first. A novel model based on Raoult’s law is introduced and validated with experimental data. The model allows the computation of the liquid and vapor phase composition of refrigerant/oil-mixtures using pressure and temperature measurements. In the next step, the performance of the four investigated refrigerants is evaluated experimentally in an ORC test rig. Therefore, the same experimental program was repeated for every refrigerant in order to ensure a fair comparison. To conclude the evaluation of the refrigerants, a Life Cycle Assessment (LCA) is conducted for a theoretical geothermal power plant operated with the four considered refrigerants.The experimental results show, that R1224yd(Z) as well as R1233zd(E) are very suitable low-GWP alternatives for R245fa and could be used as drop-in replacements. R1336mzz(Z) on the other hand shows significantly lower system efficiencies and power outputs compared to the other refrigerants. The highest power output and system efficiency is however still achieved by the state of the art refrigerant R245fa, but these quantities are only slightly lower for R1233zd(E) and R1224yd(Z) . The LCA based on the experimental results for a hypothetical large-scale geothermal ORC application reveals, that despite the slight performance decrease, the application of low-GWP fluids decreases the CO2-equivalent of the system significantly. The usage of R1233zd(E) could decrease the CO2-equivalent by 67% compared to R245fa.

Geochemical Distinction Between Altered Oceanic Basalt- and Seafloor Sediment-Derived Fluids in the Mantle Source of Mafic Igneous Rocks in Southwestern Tianshan, Western China

AbstractThe role of subducting oceanic crust-derived fluids in generating mafic arc magmatism has been widely documented. However, the subducting oceanic crust is generally composed of basaltic igneous crust and seafloor sediment, which may give rise to different compositions of liquid phases causing metasomatism of the mantle wedge. Because of the similarity in enrichment of fluid-mobile incompatible elements in the two sources of subduction zone fluids, it has been a challenge to distinguish between them when studying the products of mafic arc magmatism. This difficulty is overcome by a combined study of whole-rock Li isotopes and zircon O isotopes in addition to whole-rock major-trace elements and Sr–Nd–Hf isotopes in Late Paleozoic mafic igneous rocks from southwestern Tianshan in western China. Zircon U–Pb dating yields consistent ages of 313 ± 3 Ma to 305 ± 1 Ma for magma crystallization. The mafic igneous rocks exhibit arc-like trace element distribution patterns and depleted whole-rock Nd–Hf isotopes but slightly high (87Sr/86Sr)i ratios of 0·7039– 0·7057. They also show positive zircon εHf(t) values and slightly higher zircon δ18O values of 5·2–7·6‰. There are covariations of whole-rock Sr isotopes with Th/La and Rb/Nb ratios, indicating a contribution from terrigenous sediment-derived fluids to their mantle source in addition to basaltic igneous crust-derived fluids. Based on the slightly higher zircon δ18O values but variably lower whole-rock δ7Li values of -0·8 to 3·5‰ for the target rocks than those of mantle respectively, both altered oceanic basalt- and terrigenous sediment-derived fluids are identified in the mantle source of these mafic igneous rocks. Model calculations for trace elements and Sr–Nd–Li isotopes further confirm that the geochemical compositions of these mafic igneous rocks can be explained by chemical reaction of depleted MORB mantle peridotite with the mixed fluids to generate ultramafic metasomatites at subarc depths. Therefore, chemical metasomatism of the mantle wedge is a key mechanism for the incorporation of crustal components into the source of arc-like mafic igneous rocks above oceanic subduction zones.

Prediction of Carbon Dioxide Solubility in Monoethylene Glycol /Water Mixtures Employing SRK and PR-EOS with Two Different Mixing Rules

A thermodynamic models of binary system carbon dioxide (1) - mixture (monoethylene glycol (MEG)/water) (2) at pressure up to 5 bar and temperatures (288-348 K) are established using SRK and PR equation of state (EOS). Modified van der Waal’s and quadratic mixing rules are coupled with the two Equation of state. Prediction of carbon dioxide in pure water and MEG were studied as well using same equations. Average absolute deviation in liquid-phase compositions percentage AADx % used for adjustable parameter optimization. The predicted results are showed very good agreement with the experimental data in all the systems examined. Quadratic mixing rule in all systems gives AADx % lower than Modified van der Waal’s and the values differences can be ignored.

Phase Equilibria for Three Ternary Systems (Water + n-Propanol + n-Butyl Acetate, Ethyl Butyrate or n-Pentyl Acetate) at T = (293.15, 303.15, 313.15) K

The experimental liquid phase compositions of the ternary systems (water + n-propanol + n-butyl acetate, ethyl butyrate or n-pentyl acetate) were measured at T = (293.15, 303.15 and 313.15) K under atmospheric pressure. The thermodynamic modified and extended UNIQUAC models were applied to correlate and analyze the experimental values. Ternary phase diagrams at the experimental temperatures were plotted and compared. The linear trend of the measured liquid–liquid equilibrium data was confirmed by using the Bachman equation. Distribution coefficients and separation factors were applied to evaluate extracting capability of n-butyl acetate, ethyl butyrate and n-pentyl acetate to separate n-propanol from (n-propanol + water) solutions.

The non-ideal evaporation behaviors of ethanol/heptane droplets: Impact on diameter, temperature evolution and the light scattering by droplet at the rainbow angle

This paper aims to investigate the influence of non-ideal vapor-liquid equilibrium (VLE) on the heating and evaporation of ethanol/heptane binary droplets. Three correction parameters, the activity coefficient, the Poynting factor, and the fugacity coefficient, are incorporated in the Effective Thermal Conductivity Model (ECM) and Effective Diffusivity Model (EDM) to present the non-ideal behavior at droplet surface. Rainbow theory was used to present the difference between the ideal and non-ideal models by predicting the scattering light patterns with the obtained results. The evaporation process of ethanol/heptane droplet was performed by the ideal and non-ideal VLE methods, with the ambient temperature varying from 473 K to 673 K, ambient pressure of 1 and 10 bar, together with the initial mass fraction of heptane in liquid phase ranging from 0 to 1. The results indicate firstly, the effect of non-ideal behavior on evaporation constant and temperature evolution is more pronounced for the droplets with initial heptane mass fraction of 25% and 50% inside the mixture. This reveals that when the lighter component dominates the mixture, the assumption of an ideal mixture is less accurate. Secondly, for the non-ideal system, the liquid phase composition is an important factor in deciding the evaporation order of different components in the mixture. In some situations, the less volatile fuel evaporates faster than the more volatile part in the mixture. Moreover, the influence of non-ideal behavior is attenuated under high ambient temperature and pressure conditions as presented by the relatively smaller value of separation factor. Lastly, the obtained simulation results were analyzed with the rainbow theory by predicting the scattering light patterns by droplet at the rainbow angle. The difference in the scattering light patterns was analyzed.

DMC-Mediated Copolymerization of CO2 and PO—Mechanistic Aspects Derived from Feed and Polymer Composition

The influence of composition of liquid phase on composition of poly(propylene ether carbonates) in the copolymerization of CO2 with propylene oxide (PO), mediated by a zinc chloride cobalt double metal cyanide, was monitored by FT-IR/CO2 uptake/size exclusion chromatography in batch and semi-batch mode. The ratio of mol fractions of carbonate to ether linkages F (~0.15) was found virtually independent on the feed between 60 and 120 °C. The presence of CO2 lowers the catalytic activity but yields more narrowly distributed poly(propylene ether carbonates). Hints on diffusion and chemistry-related restrictions were found underlying, broadening the distribution. The incorporation of CO2 seems to proceed in a metal-based insertion chain process, ether linkages are generated stepwise after external nucleophilic attack. The presence of amines resulted in lower activities and no change in F. An exchange of chloride for nitrate in the catalyst led to a higher F of max. 0.45. The observations are interpreted in a mechanistic scheme, comprising surface-base-assisted nucleophilic attack of external weak nucleophiles and of mobile surface-bound carboxylato entities on activated PO in competition to protonation of surface-bound alkoxide intermediates by poly(propylene ether carbonate) glycols or by surface-bound protons. Basic entities on the catalyst may promote CO2 incorporation.

Chemical and Phase Equilibria in the Reaction between NO and O2 in the Presence of Water and CO2 at 298.15 K up to 3 MPa

New experimental data for cosolubility of carbon dioxide, nitric oxide, and nitrogen dioxide produced from the reaction in situ between nitric oxide and dioxygen in pure water at 298.15 K and up to 3 MPa are presented in this work. These data are essential to develop and validate thermodynamic models for CO2 and other gases capture and storage processes. In this work, measurements of carbon and nitrogen oxide solubilities in water are achieved; the liquid phase composition at the thermodynamic equilibrium was determined by analytical methods (ion chromatography), pH-metric titration, and a static synthetic method, and the gaseous phase composition was determined by two infrared spectrometers. The experimental apparatus and the analytical procedure were validated by studying the CO2 + water systems and comparing the experimental measurements with the literature data. On the other hand, the measurements of NO2 + water systems are original and do not exist in the literature. In order to study the behavior of the nitrogen dioxide in water, a suitable reaction mechanism was carefully chosen to predict the composition of the different nitrogen species (NO, NO2, N2O3, N2O4, HNO2, H+, NO2–, HNO3, and NO3–.) in the aqueous medium at 298.15 K. Then, a Henry constant for the studied nitric oxide systems was calculated. Some difficulties have been encountered in the stabilization of the nitrogen dioxide partial pressure due to its metastable conditions; therefore, data related to the Henry constant of this compound will not be reported.

Kinetics, Thermodynamics, and Scale-Up of an Azeotropic Drying Process: Mapping Rapid Phase Conversion with Process Analytical Technology

Distillation processes with several solid-state phases and dynamic multicomponent liquid-phase compositions can be challenging to understand and scale up because of complexity of the thermodynamics...

Impact of droplet composition on the nucleation rate and morphology of vapor-liquid-solid GeSn nanowires

It is well-known that the chemical potential which drives the vapor-liquid-solid growth of semiconductor nanowires is strongly affected by the liquid phase composition. Here, we investigate theoretically how the droplet composition influences the nucleation of Au-catalyzed GeSn nanowires on Ge(111) and Si(111) substrates. We compare the chemical potentials in an Au-Ge-Sn catalyst droplet before and after adding Ga and/or Si atoms. It is found that the presence of these atoms enhances the nucleation rate of nanowires on both substrates. Theoretical results are compared to experimental data on GeSn nanowires grown in a hot-wall reduced pressure chemical vapor deposition reactor. It is shown that the intentional addition of Ga in the de-wetting step improves the uniformity of the nanowire dimensions and yields higher density of nanowires over Ge(111) substrates. The nanowire growth on Si(111) substrate occurs only when Ga and/or Si are added to Au droplets. These results show that controlling the composition of the catalyst droplet is crucial for improving the quality of GeSn nanowires.

Combined Experimental and Theoretical Studies on the Prediction of the Isobaric Vapor–Liquid Association Phenomena for Binary and Ternary Mixtures of Water, Ethanoic Acid, and Propanoic Acid

It is a considerable challenge for the phase behavior of chemical separation industry to correlate and predict the vapor–liquid equilibria (VLE) data of the binary and ternary systems containing associating components because it is not known how these forms exist in the experimental condition, such as homogeneous or heterogeneous dimers or trimers, even polymers, and so on. Herein, VLE data for the associating ternary system, water + ethanoic acid + propanoic acid, and the three-constituent binary systems have been measured by different liquid-phase compositions using a Fischer ebulliometer at 101.33 kPa. The structures and distribution of various clusters in water, ethanoic acid, and propanoic acid systems were fully optimized at the B3LYP/6-31+G(d) level of theory using Gaussian 09. Then, we developed a strategy that could calculate the liquid activity coefficients by considering the distribution of the associating components in the strong association systems. This method is called the discrete clusters (DC) model, and, for comparison, Wilson, NRTL, and UNIQUAC models were employed to correlate the VLE data for the three-constituent binary systems. Also, the VLE data of the ternary system were estimated from the DC, Wilson, NRTL, and UNIQUAC models without any additional adjustment. Our DC model, which considered the explicit number of various clusters, showed better agreement and a smaller deviation from the experimental data. These VLE data derived from the DC model can be used for the design and simulation of the distillation behavior of the binary and ternary association systems.

Non-iterative phase-equilibrium model of the H2O-CO2-NaCl-system for large-scale numerical simulations

This article features a simple method for describing the phase equilibrium of the ternary water–salt–carbon dioxide system. At first, an iterative solution is shown using well known equations of state and solubility correlations to predict the compositions of liquid and gas phases in a saline aquifer. By virtue of several assumptions, iterations can be avoided entirely in order to use the method for demanding large-scale numerical simulations. Subsequently, the iterative method as well as the simplification are evaluated against experimental data. Both solutions provide adequate accuracy for engineering problems such as subsurface carbon dioxide storage.

Systematic Investigations on Continuous Fluidized Bed Crystallization for Chiral Separation

A recently developed continuous enantioseparation process utilizing two coupled fluidized bed crystallizers is systematically investigated to identify essential correlations between different operation parameters and the corresponding process performance on the example of asparagine monohydrate. Based on liquid phase composition and product crystal size distribution data, it is proven that steady state operation is achieved reproducibly in a relatively short time. The process outputs at steady state are compared for different feed flow rates, supersaturations, and crystallization temperatures. It is shown that purities >97% are achieved with productivities up to 40 g/L/h. The size distribution, which depends almost exclusively on the liquid flow rate, can be easily adjusted between 260 and 330 µm (mean size) with an almost constant standard deviation of ±55 µm.