نتایج جستجو برای: unifac
تعداد نتایج: 154 فیلتر نتایج به سال:
COSMO-RS is a novel and efficient method for the a-priori prediction of thermodynamic properties of mixtures. It is based on unimolecular quantum chemical calculations that provide the necessary information for the evaluation of molecular interactions in liquids. Thus, the method provides an alternative to group contribution methods such us UNIFAC for the true prediction of activity coefficient...
The search of new renewable fuels and the interest finding uses for abundant subproducts many industrial processes have prompt Eni S.p.A to develop a technology producing biofuels from glycerol. One compounds involved in this process is 2-ethyl-4-ethoxymethyl-1,3‑dioxolane (PrEDO). In paper their temperature - vapor pressure curve has been determined experimentally as well binary vapor–liquid e...
Vapor pressure (P) is a fundamental property controlling the gas–particle partitioning of organic species. Therefore this pure substance property is a critical parameter for modeling the formation of secondary organic aerosols (SOA). Structure–property relationships are needed to estimate P because (i) very few experimental data for P are available for semi-volatile organics and (ii) the number...
Isobaric vapor-liquid equilibrium measurements are reported for the binary mixture of Methyl acetate and Isopropylbenzene at 97.3 kPa. The measurements have been performed using a vapor recirculating type (modified Othmer's) equilibrium still. The mixture shows positive deviation from ideality and does not form an azeotrope. The activity coefficients have been calculated taking into considerati...
A novel approach for enclosing all heterogeneous and reactive azeotropes in multi-component mixtures is presented. The thermodynamic conditions for azeotropy form a system of nonlinear equations. A deterministic global optimization approach is introduced in which the global optimization problem may contain multiple global minima and there is a one-to-one correspondence between each global minim...
In this work is examined whether it is possible to predict solid-liquid-vapor phase equilibrium of ternary systems used in the SAS processing by the Peng-Robinson equation of state coupled with the LCVM mixing rules and the UNIFAC method for excess Gibbs free energy calculation. The enthalpy of fusion and the melting point temperature are estimated by group contribution methods. The results sho...
Boiling points have been determined at 101.33 kPa for the binary mixtures of sulfolane + o-xylene, sulfolane + m-xylene, sulfolane+p-xylene, sulfolane+ethylbenzene and sulfolane+1,2,4-trimethylbenzene. Calculations of the non-ideality of the vapor phase were made with the second virial coefficients evaluated from the Hayden–O’Connell method. The binary parameters for five activity coefficient m...
Group contribution methods such as the UNIFAC are of major interest to researchers and engineers involved synthesis, feasibility studies, design and optimization of separation processes as well as other applications of industrial use. Reliable knowledge of the phase equilibrium behavior is crucial for the prediction of the fate of the chemical in the environment and other applications. The obje...
تراوش تبخیری یک فرایند غشایی کارامد برای جداسازی فاز مایع، در دهه های گذشته می باشد که شاهد پیشرفت قابل توجه و ترقی غیر منتظره در جنبه های اصولی و کاربردی بوده است. تاکنون حجم قابل توجهی از داده های تجربی بدون هرگونه مدل قابل و کارامدی برای توصیف این پدیده توسط محققین ارائه شده است. مکانیسم تراوش تبخیری در غشاء پلیمری توسط فرایند سه مرحله ای تشریح شده است : حلالیت، نفوذ و تبخیر (یا دفع). در این...
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