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1.
Bubble temperatures at 95?kPa over the entire composition range are measured for the five binary systems formed by 1,2-dimethylbenzene with 2-propanol, 1-butanol, 2-butanol, 2- methylpropan-1-ol, and 2-methylpropan- 2-ol. A Swietoslawski - type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model. 相似文献
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T. E. Vittal Prasad D. H. L. Prasad P. G. Naveen B. Santosh Kumar 《Chemical Engineering Communications》2004,191(7):998-1002
Bubble temperatures at 95 kPa over the entire composition range were measured for the three binary systems formed by 1,4-dimethylbenzene with iso-, sec-, and tert- butanols. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model. 相似文献
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T. E. VITTAL PRASAD D. H. L. PRASAD P. G. NAVEEN B. SANTOSH KUMAR 《Chemical Engineering Communications》2013,200(7):998-1002
Bubble temperatures at 95 kPa over the entire composition range were measured for the three binary systems formed by 1,4-dimethylbenzene with iso-, sec-, and tert- butanols. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model. 相似文献
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T. E. Vittal Prasad D. H. L. Prasad G. V. Ramserish P. Satya Kishore 《Chemical Engineering Communications》2003,190(2):171-176
Boiling point temperatures at 95 kPa over the entire composition range are measured for the three binary systems formed by 1,3-dimethylbenzene with methanol, 1-propanol, and 2-propanol. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model. 相似文献
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T. E. Vittal Prasad D. H. L. Prasad G. Mallikarjun Peer Ahmed Suchi Singh P. Lavanya Reddy 《Chemical Engineering Communications》2008,195(7):738-744
Bubble point temperatures at 94.95 kPa, over the entire composition range, are measured for the binary mixtures of nitrobenzene with: cyclohexane, n-hexane, n-heptane, n-decane, and o-, m-, and p-xylenes, using a Swietoslawski-type ebulliometer. Liquid phase composition versus bubble point temperature measurements are well represented by the Wilson model. Computed values of the excess Gibbs energy are presented and discussed. 相似文献
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阐述了利用环氧丙烷和甲醇在催化剂HM-9512存在下,通过选择性开环加成制备1-甲氧基-2-丙醇的工艺过程。讨论了几个主要反应因素对产物选择性和收率的影响,确定了适宜的工艺条件和产品的检测方法。 相似文献
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J.C.G. CALADO E.J.S. GOMES DE AZEVEDO V.A.M. SOARES 《Chemical Engineering Communications》2013,200(1-4):149-163
Two series of binary liquid mixtures containing either ethylene or ethane have been investigated, at one or more temperatures (usually at the triple-point temperature of the component with the higher melting-point). In the ethylene series liquid-vapour equilibrium and liquid density studies were carried out for mixtures with methane, krypton and xenon; the heats of mixing were also measured for the ethylene + krypton mixtures. In the ethane series, which comprised mixtures with methane, argon, krypton and xenon, all three properties were measured except for the ethane + methane and ethane + argon systems where the enthalpies of mixing were already known. The ethylene + ethane system was also investigated at 161.39 K. The results have been used to estimate the thermodynamic excess functions GE , VE and HE . The GE values decrease, within each series, as one moves from the lighter to the heavier rare gas, the values being lower in the ethane series. For the ethane + xenon mixtures both GE and HE are negative, showing a weak attraction between the two molecules. The VE values for the mixtures of hydrocarbons suggest the probable formation of interlocking structures between the two components. The values of the thermodynamic excess functions have been interpreted in the light of the model of Frisch-Longuet Higgins-Widom for the liquid state. 相似文献
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以甲醇和环氧丙烷为反应物,采用均相连续反应精馏法合成了2-羟丙基甲醚。对三乙胺、氢氧化钠、氢氧化钾、碳酸钠和碳酸钾五种催化剂的催化活性和选择性进行了研究。考察了以三乙胺为催化剂时进料摩尔比和环氧丙烷进料速率对环氧丙烷转化率、2-羟丙基甲醚选择性及收率的影响,并对反应精馏塔的温度分布进行了讨论 相似文献
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An analytical expression for the calculation of the pressure and liquid mole fraction at the VLE of ethane/light hydrocarbon binary mixtures is proposed. The model is based on a simple analytical expression for the vapor pressure of pure non-polar fluids, which, for a given temperature, only requires as input the values of the Lennard-Jones molecular parameters and the acentric factor. A properly modified Lorentz-Berthelot mixing rule is used, the interaction parameters being given as simple functions of the temperature and composition with eight constants for each binary mixture. The model is shown to reproduce accurately and simply the pressure (for a given liquid mole fraction) or the liquid composition (for a given pressure) of six ethane + hydrocarbon systems at different temperatures. 相似文献
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The synergistic extraction of zinc and cadmium (M2*) from sulphate, nitrate and perchlorate media with mixtures of 1-phenyl-3-methyl-4-benzoylpyra2ol-5-ol (HL) and n-dodecylammoniura salts (DDAH*,X?) in toluene has been studied. In sulphate medium, the lipophilic ammonium pyrazololate (DDAK*L?) is the predominating ammonium species : the synergy observed can be considered as the addition of (DDAH*,L?) on HL2 perchlorate and nitrate media, the amphiphilic ammonium salts {DDAH*, CIO4?) and (DDAH+N03 ?) predominate, leading to the formation of an aqueous emulsion in equilibrium with a clear organic phase. Metal distribution curves show that the formation of the lipophilic synergistic species (DDAH+ML2 ?) results from a X?/ML3 ? exchange in the interfacial region between the aqueous and the organic phase. The addition of n-octanol or 4-nonylphenol in the organic phase turns the emulsion into a micro-emulsion whereas the substitution of toluene by chloroform largely decreases the emulsion stability. 相似文献
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Gholamreza Vakili-Nezhaad Mostafa Vatani Morteza Asghari 《Chemical Engineering Communications》2013,200(8):1102-1120
One of the most important applications of thermodynamics is the accurate prediction of fluid phase equilibria problems related to real chemical engineering processes. Various equations of state as well as activity coefficient models have been developed for such calculations with many interaction, size, and randomness parameters, which should be optimized based on powerful and effective computational methods. Leading to globally optimal values, genetic algorithm (GA) as a powerful and effective tool can be used for prediction of the interaction parameters of thermodynamic models in complex liquid-liquid equilibrium (LLE) systems. It requires only lower and upper bounds for the interaction parameters and the necessary initial guesses are produced automatically. In the present work, based on the GA method, a global optimization procedure is introduced for calculation of the binary interaction and nonrandomness parameters of NRTL, NRTL1, and NRTL2 activity coefficient models for 20 ternary aromatic extraction systems containing 16 different ionic liquids at various temperatures. The values of the parameters along with the root-mean-square deviations (rmsd) are reported. The results, in terms of rmsd for NRTL, NRTL1, and NRTL2 models, are very satisfactory, with global values of 0.0031, 0.0020, and 0.0053 for 187 tie-lines respectively. The obtained rmsd values for the NRTL model using the GA method are better than those reported in the literature. The rmsd results for the three studied models show that NRTL1 can handle the LLE calculations with more accuracy than the original NRTL and NRTL2 activity coefficient models. 相似文献
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A new process is proposed which converts CO2 and CH4 containing gas streams to synthesis gas, a mixture of CO and H2 via the catalytic reaction scheme of steam-carbon dioxide reforming of methane or the respective one of only carbon dioxide reforming of methane, in permeable (membrane) reactors. The membrane reformer (permreactor) can be made by reactive or inert materials such as metal alloys, microporous ceramics, glasses and composites which all are hydrogen permselective. The rejected CO reacts with steam and converted catalytically to CO2 and H2 via the water gas shift in a consecutive permreactor made by similar to the reformer materials and alternatively by high glass transition temperature polymers. Both permreactors can recover H2 in permeate by using metal membranes, and H2 rich mixtures by using ceramic, glass and composite type permselective membranes. H2 and CO2 can be recovered simultaneously in water gas shift step after steam condensation by using organic polymer membranes. Product yields are increased through permreactor equilibrium shift and reaction separation process integration.
CO and H2 can be combined in first step to be used for chemical synthesis or as fuel in power generation cycles. Mixtures of CO2 and H2 in second step can be used for synthesis as well (e.g., alternative methanol synthesis) and as direct feed in molten carbonate fuel cells. Pure H2 from the above processes can be used also for synthesis or as fuel in power systems and fuel cells. The overall process can be considered environmentally benign because it offers an in-situ abatement of the greenhouse CO2 and CH4 gases and related hydrocarbon-CO2 feedstocks (e.g., coal, landfill, natural, flue gases), through chemical reactions, to the upgraded calorific value synthesis gas and H2, H2 mixture products. 相似文献
CO and H2 can be combined in first step to be used for chemical synthesis or as fuel in power generation cycles. Mixtures of CO2 and H2 in second step can be used for synthesis as well (e.g., alternative methanol synthesis) and as direct feed in molten carbonate fuel cells. Pure H2 from the above processes can be used also for synthesis or as fuel in power systems and fuel cells. The overall process can be considered environmentally benign because it offers an in-situ abatement of the greenhouse CO2 and CH4 gases and related hydrocarbon-CO2 feedstocks (e.g., coal, landfill, natural, flue gases), through chemical reactions, to the upgraded calorific value synthesis gas and H2, H2 mixture products. 相似文献
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An experimental study on the degradation of aqueous solutions of alkanolamine blends, under the presence of carbon dioxide and hydrogen sulfide, was carried out. The studied alkanolamines were: diethanolamine (DEA), methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP). Degradation experiments were carried out at a temperature of 200°C. The mass fraction of DEA and MDEA in the studied aqueous solutions was 10% and 35%, respectively. AMP was incorporated into the MDEA-DEA aqueous solutions, with concentrations of (0-8) mass fraction. Partially degraded alkanolamine aqueous solutions were analyzed, after about 90 hours, by gas chromatography.
It was found that in all the studied alkanolamine aqueous solutions the MDEA degrades more slowly than DEA under the same experimental conditions. Degradation of both alkanolamines was found to be almost independent of the AMP concentration. AMP exhibits an intermediate stability; it is more resistant to degradation than DEA but less than MDEA. In addition, thermal degradation of DEA and MDEA is minimal up to 200°C. 相似文献
It was found that in all the studied alkanolamine aqueous solutions the MDEA degrades more slowly than DEA under the same experimental conditions. Degradation of both alkanolamines was found to be almost independent of the AMP concentration. AMP exhibits an intermediate stability; it is more resistant to degradation than DEA but less than MDEA. In addition, thermal degradation of DEA and MDEA is minimal up to 200°C. 相似文献
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A new process is proposed which converts CO2 and CH4 containing gas streams to synthesis gas, a mixture of CO and H2 via the catalytic reaction scheme of steam-carbon dioxide reforming of methane or the respective one of only carbon dioxide reforming of methane, in permeable (membrane) reactors. The membrane reformer (permreactor) can be made by reactive or inert materials such as metal alloys, microporous ceramics, glasses and composites which all are hydrogen permselective. The rejected CO reacts with steam and converted catalytically to CO2 and H2 via the water gas shift in a consecutive permreactor made by similar to the reformer materials and alternatively by high glass transition temperature polymers. Both permreactors can recover H2 in permeate by using metal membranes, and H2 rich mixtures by using ceramic, glass and composite type permselective membranes. H2 and CO2 can be recovered simultaneously in water gas shift step after steam condensation by using organic polymer membranes. Product yields are increased through permreactor equilibrium shift and reaction separation process integration. CO and H2 can be combined in first step to be used for chemical synthesis or as fuel in power generation cycles. Mixtures of CO2 and H2 in second step can be used for synthesis as well (e.g., alternative methanol synthesis) and as direct feed in molten carbonate fuel cells. Pure H2 from the above processes can be used also for synthesis or as fuel in power systems and fuel cells. The overall process can be considered environmentally benign because it offers an in-situ abatement of the greenhouse CO2 and CH4 gases and related hydrocarbon-CO2 feedstocks (e.g., coal, landfill, natural, flue gases), through chemical reactions, to the upgraded calorific value synthesis gas and H2, H2 mixture products. 相似文献
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《Chemical Engineering Communications》2007,194(5):635-647
Densities of the binary systems of benzene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are positive for the four binaries studied. 相似文献
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