Extractive distillation modeling of the ternary system 2-methoxy-2-methylpropane-methanol-butan-1-ol

2012 ◽  
Vol 66 (6) ◽  
Author(s):  
Zuzana Labovská ◽  
Pavol Steltenpohl ◽  
Elena Graczová

AbstractInfluence of model complexity on the separation equipment performance was investigated. As an example, separation of azeotrope formed by 2-methoxy-2-methylpropane and methanol was considered using butan-1-ol as an extractive solvent. Non-equilibrium model of a column for extractive distillation accounting for the mass and heat transfer rates was composed according to the rigorous Maxwell-Stefan theory. An empirical AICHE correlation was adopted for the calculation of binary mass transfer coefficients at column trays. Results of the column steady-state operation were compared with those obtained assuming different equilibrium models. Effect of the quality of the vapor-liquid equilibrium (VLE) description on the results of the separation simulation considering real behavior of either liquid or both equilibrium phases was tested. Real behavior of the liquid phase was computed according to the NRTL equation taking into account binary and, in some cases, also ternary equilibrium data. In case of real behavior of the vapor phase, the equation of state in the form of virial expansion was employed. Qualitative agreement was found comparing the simulation results calculated by equilibrium and non-equilibrium models of the extractive distillation column while using the same description of ternary VLE.

2017 ◽  
Vol 38 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Artur Kubiczek ◽  
Władysław Kamiński

AbstractRoom-temperature ionic liquids (RTILs) are a moderately new class of liquid substances that are characterized by a great variety of possible anion-cation combinations giving each of them different properties. For this reason, they have been termed as designer solvents and, as such, they are particularly promising for liquid-liquid extraction, which has been quite intensely studied over the last decade. This paper concentrates on the recent liquid-liquid extraction studies involving ionic liquids, yet focusing strictly on the separation of n-butanol from model aqueous solutions. Such research is undertaken mainly with the intention of facilitating biological butanol production, which is usually carried out through the ABE fermentation process. So far, various sorts of RTILs have been tested for this purpose while mostly ternary liquid-liquid systems have been investigated. The industrial design of liquid-liquid extraction requires prior knowledge of the state of thermodynamic equilibrium and its relation to the process parameters. Such knowledge can be obtained by performing a series of extraction experiments and employing a certain mathematical model to approximate the equilibrium. There are at least a few models available but this paper concentrates primarily on the NRTL equation, which has proven to be one of the most accurate tools for correlating experimental equilibrium data. Thus, all the presented studies have been selected based on the accepted modeling method. The reader is also shown how the NRTL equation can be used to model liquid-liquid systems containing more than three components as it has been the authors’ recent area of expertise.


2020 ◽  
Vol 26 (4) ◽  
pp. 189
Author(s):  
Achmad Zamroni ◽  
Heri Widiyastuti ◽  
Suwarso Suwarso

Peningkatan strategi pengelolaan perikanan pelagis kecil terutama di perairan Laut Jawa tidak hanya dengan menilai stok ikan dan perikanannya, akan tetapi diperlukan juga menilai risiko dampak dari pengelolaan. Dalam tulisan ini disebutkan status estimasi stok dan risiko yang melebihi hasil tangkapan maksimum yang berkelanjutan/Maximum Sustainable Yieald (MSY) terkait dengan nilai referensi terhadap beberapa tingkat tangkapan alternatif yang dihasilkan dari penilaian stok dan risiko penangkapan. Analisis yang digunakan adalah model dinamika biomassa ikan dengan metode non-equilibrium. Data yang digunakan berasal dari PPI Sarang, Rembang yang merupakan basis perikanan pelagis kecil terbesar di Laut Jawa selain Pekalongan. Hasil analisis menunjukkan bahwa nilai MSY yang diperoleh adalah 13.820 ton yang dihasilkan dari upaya penangkapan sekitar 1.759 trip kapal pukat cincin mini. Jika pemanfaatan perikanan sesuai dengan kondisi saat ini, maka estimasi nilai risiko akan berada pada tingkat risiko tinggi, begitu juga jika tingkat pemanfaatan berada pada nilai MSY nya. Nilai risiko akan turun menjadi sedang-tinggi jika pemanfaatan dikurangi 10% - 20% dari kondisi saat ini. Jika tingkat pemanfaatan dikurangi 30% atau lebih, maka nilai risiko dalam 10 tahun berikutnya akan berada pada kondisi sedang-rendah.Improving the management strategy of small pelagic fisheries, especially in the waters of the Java Sea, not only by assessing fish stocks and fisheries, but also needs to determine the risk of management impacts. In this paper, it is stated that the status of stock and risk estimation that exceeds the Maximum Sustainable Yield (MSY) is related to the reference value in several alternative catch levels resulting from stock and risk assessment. The analysis used is a fish biomass dynamics model with a non-equilibrium method. The data used was from TPI Sarang in Rembang, which is one of the largest small pelagic fisheries bases in the Java Sea. Results show that the MSY value obtained is 13,820 tons resulting from the capture effort of approximately 1,759 mini purse seine trips. Suppose the fishery utilization is in accordance with the current conditions, in that case, the estimated risk value will be at a high-risk level, and also if the utilization level is at the MSY value. The risk value will decrease to moderate-high if utilization is reduced by 10% - 20% from the current condition. If the utilization level is reduced by 30% or more, the next ten-year risk value will be in the medium-low condition.


Author(s):  
Martin Mootz ◽  
Ilias E. Perakis ◽  
Chirag Vaswani ◽  
Din H. Mudiyanselage ◽  
Xu Yang ◽  
...  

Author(s):  
Francisco J. Moraga ◽  
Martin Vysohlid ◽  
Andrew G. Gerber ◽  
Natalia Smelova ◽  
Sriram Atheya ◽  
...  

Most non-equilibrium wet steam CFD analyses in the open literature have concentrated on predicting blade pressure loadings, with very few studies emphasizing turbine efficiencies. One of the few exceptions is the work of Gerber et al. [1]. In light of this, in this paper we present CFD predictions of isokinetic efficiency and Markov Loss coefficients and comparisons with measurements for the 2D cascades of White et al. [2] and Bakhtar et al. [3, 4]. Predictions were obtained using an Eulerian-Eulerian multiphase formulation, which is an extension of General Electric’s proprietary CFD turbomachinery code, TACOMA. The formulation is optimized to capture the thermodynamic loss. There is no slip between the droplets and the surrounding vapor. Comparisons with other experimental quantities are also presented as needed to ensure that the non-equilibrium wet steam physics is accurately captured. Although the non-equilibrium models used cannot capture all the loss components present in actual flows, our efficiency predictions are much closer to experimental data than those of equilibrium simulations or the Baumann rule.


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