Unusual Control Structure for High Reflux Ratio Distillation Columns

2009 ◽  
Vol 48 (24) ◽  
pp. 11048-11059 ◽  
Author(s):  
William L. Luyben
Keyword(s):  
Control Structure ◽  
Reflux Ratio ◽  
Distillation Columns

Combined balance control structure for distillation columns

1991 ◽  
Vol 30 (9) ◽  
pp. 2159-2168 ◽  
Author(s):  
Dae R. Yang ◽  
Dale E. Seborg ◽  
Duncan A. Mellichamp
Keyword(s):  
Control Structure ◽  
Balance Control ◽  
Distillation Columns

scholarly journals Design of Batch Distillation Columns Using Short-Cut Method at Constant Reflux

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Asteria Narvaez-Garcia ◽  
Jose del Carmen Zavala-Loria ◽  
Luis Enrique Vilchis-Bravo ◽  
Jose Antonio Rocha-Uribe
Keyword(s):  
Mole Fraction ◽  
Annual Cost ◽  
Quality Index ◽  
Distillation Column ◽  
Total Annual Cost ◽  
Reflux Ratio ◽  
Batch Distillation ◽  
Distillation Columns ◽  
Cut Method ◽  
Quality Indexes

A short-cut method for batch distillation columns working at constant reflux was applied to solve a problem of four components that needed to be separated and purified to a mole fraction of 0.97 or better. Distillation columns with 10, 20, 30, 40, and 50 theoretical stages were used; reflux ratio was varied between 2 and 20. Three quality indexes were used and compared: Luyben’s capacity factor, total annual cost, and annual profit. The best combinations of theoretical stages and reflux ratio were obtained for each method. It was found that the best combinations always required reflux ratios close to the minimum. Overall, annual profit was the best quality index, while the best combination was a distillation column with 30 stages, and reflux ratio’s of 2.0 for separation of benzene (i), 5.0 for the separation of toluene (ii), and 20 for the separation of ethylbenzene (iii) and purification of o-xylene (iv).

scholarly journals Modeling Gilliland Correlation using Genetic Programming

2010 ◽  
Vol 5 (5) ◽  
pp. 837 ◽  
Author(s):  
Marius Olteanu ◽  
Nicolae Paraschiv ◽  
Otilia Cangea
Keyword(s):  
Genetic Programming ◽  
Distillation Column ◽  
Petroleum Refining ◽  
Graphical Method ◽  
Analytical Form ◽  
Reflux Ratio ◽  
Programming Technique ◽  
Efficient Operation ◽  
Distillation Columns ◽  
Complex Process

The distillation process is one of the most important processes in industry, especially petroleum refining. Designing a distillation column assesses numerous challenges to the engineer, being a complex process that is approached in various studies. An important component, directly affecting the efficient operation of the column, is the reflux ratio that is correlated with the number of the theoretical stages, a correlation developed and studied by Gililland. The correlation is used in the case of simplified control models of distillation columns and it is a graphical method. However, in many situations, there is the need for an analytical form that adequately approximates the experimental data. There are in the literature different analytical forms which are used taking into account the desired precision. The present article attempts to address this problem by using the technique of Genetic Programming, a branch of Evolutionary Algorithms that belongs to Artificial Intelligence, a recently developed technique that has recorded successful applications especially in process modeling. Using an evolutionary paradigm and by evolving a population of solutions or subprograms composed of carefully chosen functions and operators, the Genetic Programming technique is capable of finding the program or relation that fits best the available data.

scholarly journals Comparison of various column packing materials efficiency for hydrocarbons and aqueous mixtures

2019 ◽  
Vol 33 (2) ◽  
pp. 183-190
Author(s):  
Jiří Zbytovský ◽  
Tomáš Sommer ◽  
Martin Zapletal ◽  
Jiří Trejbal
Keyword(s):  
Acetic Acid ◽  
Aqueous Solutions ◽  
Binary Mixtures ◽  
Separation Efficiency ◽  
Reflux Ratio ◽  
Aqueous Mixtures ◽  
Distillation Columns ◽  
Future Design ◽  
Relative Separation ◽  
Column Packings

The efficiency of industrial column packings is commonly tested by standard hydrocarbon mixtures. However, a reduced efficiency value is often observed, particularly during distillation of aqueous mixtures. In this paper, distillation experiments with various binary mixtures were carried out on different column packings to evaluate relative separation efficiencies of mixtures for each packing material. Each of the binary mixtures, which comprised heptane–methylcyclohexane, ethanol–water, morpholine–water, and acetic acid–water, was distilled under atmospheric pressure and total reflux ratio on column packings that were made of PTFE, ceramic, zirconium metal, and inox steel 316. According to the results, aqueous solutions of morpholine and acetic acid generally exhibited low relative separation efficiency (in comparison with standard mixture of heptane–methylcyclohexane), ranging between 40 % and 80 %. The highest relative efficiencies were observed with packings made of steel and ceramic. These observations will be useful for the future design of distillation columns, especially for aqueous solutions.

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