Solubility of carbon monoxide and hydrogen in propylene carbonate and thermomorphic multicomponent hydroformylation solvent

Solubilities of carbon monoxide and hydrogen in propylene carbonate (PC), biphasic mixture of PC and dodecane (1:1 v/v) and thermomorphic (or temperature dependent) multicomponent solvent (TMS)-system consisting of PC, dodecane and 1,4-dioxane were measured over the temperature and pressure range of 298–343 K and 0.1–1.5 MPa, respectively, in a high pressure solubility cell. The measured solubilities were correlated by a temperature-dependent Henry's law constant and interpreted by activity coefficient models based on the regular solution theory (RST) with Yen and McKetta extension for polar solvents as well as by the UNIFAC group contribution method. The experimental data showed a very good fit in terms of Henry's law constant except for H₂–PC and CO–PC binaries. The RST-based model, that did not involve any adjustable constant, could predict the experimental solubility to within ±11.0% error. The UNIFAC model worked better with the interaction parameters computed as a linear function of temperature using a part of the experimental solubility data set. The accuracy of prediction was found to be within a maximum error of ±8.5%. The TMS system shows higher affinity for CO and H₂, which is comparable to the single phase PC. The experimental solubilities in the liquids are substantially larger than those in most other hydroformylation solvents thereby establishing its advantage over the alternative solvents for industrial use. Liquid–liquid equilibrium for the TMS system consisting of PC, dodecene and 1,4-dioxane system was also measured at 298, 353 and 373 K.     

Ozone Solubility in Liquids

A comprehensive and critical survey of the available data on ozone solubility in different liquids—in water and aqueous solutions, as well as in organic solvents has been made. Apart of comparing the data published by the various authors after 1981 for water and aqueous solutions, special attention has been paid to the effects of pH and the composition of the liquid phase (salt effect). The published data on ozone solubility in organic liquids have been compiled and the listing of such data given by Battino (1981) Battino, R. 1981. “Oxygen and Ozone”. In Solubility Data Series, 474492Oxford: Pergamon Press.  [Google Scholar] has been supplemented by the more recent ones. Special interest has been given to perfluorinated organic solvents, which exhibit high solubility for both oxygen and ozone. More formal thermodynamic approach has also been attempted. Special attention has then been paid to the predictive methods developed for oxygen solubility in non-polar and polar solvents.     

Solubility measurement and thermodynamic properties of sulfamonomethoxine in pure solvents and sulfamonomethoxine hydrate in acetone + water binary solvent at different temperature

The experimental solubility of sulfamonomethoxine in six different pure solvents (methanol,ethanol,1-propanol,l-butanol,ethyl acetate and acetone) and sulfamonomethoxine hydrate in acetone + water mixture solvents were measured from 294.55 K to 362.15 K by a laser dynamic method under atmospheric pressure.Experimental results indicated that the solubility data of sulfamonomethoxine increased with temperature increasing in pure solvents and the solubility followed this order:acetone ＞methanol ＞ ethanol ＞ ethyl acetate ＞ 1-propanol ＞ 1-butanol,but solubility in ethyl acetate was not affected significantly by temperature.In acetone + water mixture solvent,the solubility of sulfa-monomethoxine hydrate increased with temperature and the acetone concentration.Thermodynamic equations were applied to correlate solubility data of sulfamonomethoxine and sulfamonomethoxine hydrate including the modified Apelblat equation,λh equation,Wilson equation,NRTL equation,Van't Hoff-Jouyban Acree equation and modified Apel-Jouyban-Acree equation.Furthermore,thermodynamic properties △Gd,△Hd and △Sd of sulfamonomethoxine and sulfamonomethoxine hydrate in dissolution process were obtained and discussed with the modified Van't Hoff equation and Gibbs equation.     

Solubility of acid gases in a mixed solvent

The solubility of the acid gases, H₂S and CO₂, and their mixtures in a mixed solvent consisting of 55 mass% 2-piperidineethanol, 10 mass% sulfolane and 35 mass% water has been determined at 40° and 100°C. Partial pressures of the acid gases ranged from 0.05 to 5550 kPa.     

Solubility of supercritical gases in organic liquids

Chrastil (1982) [6] demonstrated that the solubility of a substance in a supercritical fluid (SCF) can be correlated with the density of the pure supercritical gas. Therefore, Chrastil's equation permits calculation of the supercritical phase composition of binary SCF + substance mixture based on the knowledge of the supercritical gas density and avoiding the use of equation of state based models.In this work, it is demonstrated that the supercritical fluid density also defines the liquid phase composition of binary systems; a density-dependent relationship is presented to calculate the solubility of supercritical gases in organic liquids. The isothermal solubility of several gases commonly employed in supercritical processing, such as carbon dioxide, methane, and ethane, in different organic liquids, including alkanes, alkenes, alcohols, acids, ketones, esters, terpenes and aromatic compounds, was successfully correlated as a function solely of the pure supercritical fluid density. As an application, pressure vs. composition phase diagrams of binary SCF + substance mixtures were obtained circumventing the use of equation of state models.     

High-pressure gas solubility in multicomponent solvent systems for hydroformylation. Part I: Carbon monoxide solubility

High-pressure gas-solubility data of carbon monoxide (CO) in various solvents like n-hexane, propylene carbonate, dimethylformamide, 1-dodecene, n-dodecanal and n/iso-tridecanal was measured for temperatures between 295 K and 364 K and pressures up to 17 MPa. The experiments were performed in a high-pressure variable-volume view cell applying the synthetic method. The binary systems investigated were correlated using the perturbed chain statistical associating fluid theory (PC-SAFT). A temperature-independent binary interaction parameter k_ij was fitted to solubility data. Based on this, to CO solubility in mixtures of n-dodecanal and 1-dodecene with various molar compositions of the two liquids (3:1, 1:1, 1:3) were predicted. CO-solubility measurements for these systems confirmed that PC-SAFT is able to accurately predict the ternary data based on the knowledge of the binary subsystems, only.     

An environmentally friendly hydroformylation using carbon dioxide as a reactant catalyzed by immobilized Ru-complex in ionic liquids

A mixed ionic liquid [bmim][Cl + NTf₂] system was successfully used as a reaction medium for Ru-catalyzed hydroformylation of 1-hexene with carbon dioxide in the absence of toxic CO and any volatile organic solvents. The yields and TONs are higher than those reported previously using conventional organic solvents. The product can be readily separated by distillation, and the reaction medium containing the Ru-catalyst was successfully recycled.     

高压搅拌釜中H_2、CO在不同液体介质中的溶解度和体积传质系数的研究

使用高压搅拌釜，应用气体间歇吸收技术，在温度３７３～５７３Ｋ、压力１．０～４．０ＭＰａ，转速８００ｒ／ｍｉｎ的实验条件下，测定了Ｈ_２、ＣＯ在液体石蜡，正二十八烷烃和ＦＴ３００蜡中的溶解度和体积传质系数。实验结果表明Ｈ_２、ＣＯ在３种液体介质中的溶解度和体积传质系数均随温度和压力的升高而增加，随液体介质分子量增加而减少。同时获得了溶解度随温度变化的关联式和气体在液体中的溶解热数据。     

Solubility of astaxanthin in supercritical carbon dioxide

The solubility of astaxanthin in carbon dioxide was measured under supercritical conditions of a pressure range from 80 to 300 bar, and temperature range from 303 to 333 K, by using a dynamic flow-type. The solubility of astaxanthin increasing from 0.42×10⁻⁵ to 4.89×10⁻⁵ with higher temperature and pressure maintains certain density of supercritical carbon dioxide. The solubility data obtained were applied to the Chrastil model, based on the density of carbon dioxide. The data fitted well with the Chrastil model at most experimental conditions.     

Solubility of niflumic acid and celecoxib in supercritical carbon dioxide

The solubility data of two fluorinated and non-steroidal anti-inflammatory drugs, niflumic acid (CAS No. 4394-00-7) and celecoxib (CAS No. 169590-42-5), in supercritical carbon dioxide were measured with a semi-flow type phase equilibrium apparatus at temperatures ranging from 313.2 K to 353.2 K and pressures up to 31 MPa. At the highest extraction temperature and pressure, the solubilities are 2.09 × 10⁻⁵ and 1.52 × 10⁻⁵ in mole fraction for niflumic acid and celecoxib, respectively. The saturated solubility data were correlated with the Chrastil model, the Mendez-Santiago–Teja equation, and the Peng–Robinson equation of state. The Chrastil model fitted the experimental data to about within the experimental uncertainty. The correlated results of the Mendez-Santiago–Teja model confirmed the consistency of the solubility data over the entire experimental conditions. Incorporating with two-parameter van der Waals one-fluid mixing rules, the Peng–Robinson equation of state represents satisfactorily the gas–solid equilibrium behavior of niflumic acid and celecoxib in supercritical carbon dioxide.     

High-pressure phase equilibrium for the hydroformylation of 1-octene to nonanal in compressed CO2

The hydroformylation reaction in supercritical carbon dioxide or CO₂-expanded liquids (CXLs) has many advantageous properties. However, accurate phase behavior and equilibrium must be known to properly understand and engineer these systems. In this investigation, the vapor-liquid equilibrium and mixture critical points of CO₂ systems with 1-octene, nonanal, 1-octene and nonanal mixtures, and mixtures of 1-octene, nonanal and syngas (CO/H₂) were measured at 60 °C up to 120 bar of pressure. The Peng-Robinson equation of state with van der Waals two-parameter mixing rule was employed successfully to correlate the binary mixture data and predict the ternary mixture data. The presence of CO/H₂ pressure increased the mixture critical points and decreased the volume expansion at any given pressure. In an actual reaction, the mixture critical point would increase throughout the reaction, while the volume of the liquid phase would decrease. These data will aid the understanding and reaction engineering for the hydroformylation reaction in CO₂-expanded liquids and supercritical fluids.     

Rapid Prediction of CO2 Solubility in Aqueous Solutions of DEA and MDEA

In the present work, a simple‐to‐use correlation is developed to predict the solubility of CO₂ in aqueous solutions of DEA and MDEA as a function of the reduced partial pressure and temperature. Using the interaction parameters generated, the model is applied to correlate the CO₂ loading in different amine solutions. The results from the proposed correlation have been compared with the reported experimental data and it was found that there is a good agreement between the observed data and the model predictions over a wide range of operating conditions in aqueous solutions of both diethanolamine (DEA) and methyldiethanolamine (MDEA).     

加压下二氧化碳在氯化钠水溶液中的溶解度

采用气液逆流双循环的溶解度测定装置测定了不同温度、不同压力、不同含盐浓度下ＣＯ２在ＮａＣｌ水溶液中的溶解度数据。应用改进的ＰＴ方程,并提出ＣＯ２和Ｈ２Ｏ交互作用参数与温度的新关系式,用于ＣＯ２在水以及ＮａＣｌ水溶液中溶解度的计算并获得满意的结果。     

Measuring oxygen, carbon monoxide and hydrogen sulfide diffusion coefficient and solubility in Nafion membranes

A Devanathan-Stachurski type diffusion cell made from a fuel cell assembly is designed to evaluate the gas transport properties of a proton exchange membrane as a function of cell temperature and gas pressure. Data obtained on this cell using the electrochemical monitoring technique (EMT) is used to estimate solubility and diffusion coefficient of oxygen (O₂), carbon monoxide (CO) and hydrogen sulfide (H₂S) in Nafion membranes. Membrane swelling and reverse-gas diffusion due to water flux are accounted for in the parameter estimation procedure. Permeability of all three gases was found to increase with temperature. The estimated activation energies for O₂, CO and H₂S diffusion in Nafion 112 are 12.58, 20 and 8.85 kJ mol⁻¹, respectively. The estimated enthalpies of mixing for O₂, CO and H₂S in Nafion 112 are 5.88, 3.74 and 7.61 kJ mol⁻¹, respectively. An extensive comparison of transport properties estimated in this study to those reported in the literature suggests good agreement. Oxygen permeability in Nafion 117 was measured as a function of gas pressures between 1 and 3 atm. Oxygen diffusion coefficient in Nafion 117 is invariant with pressure and the solubility increases with pressure and obeys Henry's law. The estimated Henry's constant is 3.5 × 10³ atm.     

Solubility of CO2 in Aqueous Piperazine and its Modeling using the Kent‐Eisenberg Approach

A systematic investigation of the equilibrium solubility of CO₂ in aqueous piperazine solutions was conducted in a double‐jacketed stirred cell reactor. The solubilities of CO₂ in the solution were measured at 20, 30, 40, and 50 °C with CO₂ partial pressures ranging from 0.4–95 kPa. Generally the aqueous piperazine solution exhibits the same characteristics as conventional alkanolamines. Increasing the CO₂ partial pressure increases the gas loading, however increasing the temperature or concentration decreases the CO₂ loading. The values of the CO₂ loading obtained confirm that the piperazine forms stable carbamates. The equilibrium solubility data were analyzed using a Kent‐Eisenberg approach. Representation of the model is generally in good agreement with that of the experimental data, especially at high temperature.     

Evolving an Accurate Decision Tree-Based Model for Predicting Carbon Dioxide Solubility in Polymers

Solubility is one of the most indispensable physicochemical properties determining the compatibility of components of a blending system. Research has been focused on the solubility of carbon dioxide in polymers as a significant application of green chemistry. To replace costly and time-consuming experiments, a novel solubility prediction model based on a decision tree, called the stochastic gradient boosting algorithm, was proposed to predict CO₂ solubility in 13 different polymers, based on 515 published experimental data lines. The results indicate that the proposed ensemble model is an effective method for predicting the CO₂ solubility in various polymers, with highly satisfactory performance and high efficiency. It produces more accurate outputs than other methods such as machine learning schemes and an equation of state approach.     

Study of the NOχ reaction with reducing gases on Fe/ZrO2 catalyst

The Fe/ZrO₂ catalyst (1% Fe by weight) shows a strong adsorption capacity toward the nitric oxide (at room temperature the ratio NOFe is ca. 0.5) as a consequence of the formation of a highly dispersed iron phase after reduction at 500–773 K. Nitric oxide is adsorbed mainly as nitrosyl species on the reduced surface where the Fe²⁺ sites are prevailing, but it is easily oxidised by oxygen forming nitrito and nitrato species adsorbed on the support. However, in the presence of a reducing gas such as hydrogen, carbon monoxide, propane and ammonia at 473–573 K the Fe-nitrosyl species react producing nitrogen, nitrous oxide, carbon dioxide and water, as detected by FTIR and mass spectrometers. The results show that nitric oxide reduction is more facile with hydrogen containing molecules than with CO, probably due the co-operation of spillover effects. Experiments carried out with the same gases in the presence of oxygen show, however, a reduced dissociative activity of the surface iron sites toward the species NO_χ formed by NO oxidation and therefore the reactivity is shifted to higher temperatures.     

Measurement,Correlation and Thermodynamics of Solubility of 2,6‐Diamino‐3,5‐Dinitropyrazine‐1‐Oxide (LLM‐105) in Eight Solvents

The solubility of insensitive explosive 2,6‐diamino‐3,5‐dinitropyrazine‐1‐oxide (LLM‐105) in dimethyl sulphoxide (DMSO), N,N‐dimethylformamide (DMF), N‐methyl‐2‐pyrrolidone (NMP), N,N‐diethylformamide (DEF), 1,4‐dioxane, 1,4‐butyrolactone, ethyl acetate and 1‐butyl‐3‐methylimidazolium trifluoromethanesulfonate ([Bmim]CF₃SO₃), were measured by a polythermal method in the temperature range of 293.15 K to 375.15 K at the atmospheric pressure. The solubility of LLM‐105 decreased in the order of DMSO, NMP, DMF, DEF, 1,4‐butyrolactone, [Bmim]CF₃SO₃, 1,4‐dioxane, ethyl acetate. With higher temperature, the solubility of LLM‐105 increased in all solvents. The solubility data was correlated against temperature with the modified Apelblat equation and Ideal solution model. In addition, the dissolution enthalpy, entropy, and mole Gibbs free energy of LLM‐105 in each solvent were also calculated from the experimental solubility data by using van′t Hoff equation with the temperature dependence. The results show that the dissolution process of LLM‐105 in these solvents is endothermic and the mechanism is the entropy‐driving. DMSO is suggested as the appropriate solvent for the cooling crystallization or drowning‐out crystallization of LLM‐105.