The Impact of Reflux Ratio on Rectification Column Theoretical Plate Number

In this paper, the computer-aided calculation is introduced to study the influences of the reflux ratio on the theoretical plate number of rectification column. It is found that the number of theoretical plates of rectification column is increasing as the decreasing of the reflux ratio, which is mainly caused by the increasing of the plate number in rectifying section. On the other hand, it is found that when reflux ratio is reduced in small interval, the theoretical plate number is increased in a zigzag shape. This interesting phenomenon is analyzed in depth and a reasonable explanation is given.

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Studies on Citronellal Extract Column Reflux Ratio and Theoretical Plate Number Design

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.773.331 ◽

2013 ◽

Vol 773 ◽

pp. 331-335

Author(s):

Zheng Hui Zhang ◽

Qiu Chen

Keyword(s):

Process Design ◽

High Vacuum ◽

Theoretical Plate ◽

Reflux Ratio ◽

Graphic Method ◽

Relational System ◽

Plate Number ◽

Operation Process ◽

Theoretical Plate Number ◽

Column Product

In this paper, the batch rectification operation is adopted to keep distillate constituting constant high vacuum, in the operation process, the operation of variable reflux ratio is carries out. Through studying the relational system of reflux ratio, column top product composition, rectification time and theoretical plate number, when the concentration of citronellal extract column product is 99%, the appropriate reflux ratio is 0.8-15, and the graphic method is used to design13 pieces of theoretical plate number of citronellal extract column, providing powerful data support for the process design of citronellal extract column.

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Action of Flow Rate of Mobile Phase in Chromatography

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.641-642.35 ◽

2013 ◽

Vol 641-642 ◽

pp. 35-38

Author(s):

Da Li Zhang ◽

Jia Jun Ke ◽

Li Zhu Lu

Keyword(s):

Theoretical Model ◽

Flow Rate ◽

Mobile Phase ◽

Plate Theory ◽

Theoretical Plate ◽

Chromatographic Peak ◽

Slip Mechanism ◽

Plate Number ◽

Theoretical Plate Number ◽

Two Phases

Chromatography has found an increasingly wide utilization in scientific and technological fields, even in some cases, has become indispensable methods for analysis and separation. Compared with its application, some common queries in chromatography still lack for good theoretical explanations, for instance, the action of flow rate of mobile phase on symmetry of peak. As is familiar to people, an increase in flow rate of mobile phase always causes theoretical plate number to decrease under normal conditions. At the same time, maybe the symmetry of chromatographic peak obviously increases, on the contrary. This result is self-contradictory. Why does the theoretical plate number not increase under the condition? Utilizing our prior paper on five plate numbers in chromatography, this paper points out why theoretical plate number decreases with an increase in symmetry of peak when flow rate of mobile phase increases. Based upon gas-solid chromatography results, the relation between flow rate of mobile phase and frequency of partition of solute, and the relation between flow rate and plate number are deduced. From the angle of theoretical model, this paper discusses the relation between solute partition in static mobile phase such as partition between two phases in plate theory and solute partition in flowing mobile phase such as Martin-Synge partition in slip mechanism, and their characteristics.

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effective theoretical plate number of a chromatographic column

IUPAC Compendium of Chemical Terminology ◽

10.1351/goldbook.e01898 ◽

2008 ◽

Keyword(s):

Theoretical Plate ◽

Chromatographic Column ◽

Plate Number ◽

Theoretical Plate Number

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Non-Gaussian Theoretical Plate Number in Chromatography

Asian Journal of Chemistry ◽

10.14233/ajchem.2015.17388 ◽

2015 ◽

Vol 27 (5) ◽

pp. 1607-1614

Author(s):

Zhang Dali ◽

Ke Jiajun ◽

Lu Lizhu

Keyword(s):

Theoretical Plate ◽

Plate Number ◽

Theoretical Plate Number ◽

Non Gaussian

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New Progress of Plate Model of Chromatogram: Five Distinct Plate Numbers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.1291 ◽

2011 ◽

Vol 393-395 ◽

pp. 1291-1294 ◽

Cited By ~ 1

Author(s):

Da Li Zhang ◽

Jia Jun Ke ◽

Li Zhu Lu

Keyword(s):

Elution Curve ◽

Theoretical Plate ◽

Efficiency Index ◽

Asymmetry Index ◽

Plate Model ◽

Slip Mechanism ◽

Plate Number ◽

Theoretical Plate Number ◽

New Equation

The five plate numbers were peak plate number (q’), slip-mechanism plate number (q), theoretical plate number (n0), real plate number (n) and plate-model plate number (q0). Slip mechanism was introduced into plate model and then a new equation of elution curve was deduced. The relational expression of five plate numbers was deduced through the new equation. Peak plate number and slip-mechanism plate number were new plate numbers derived from slip mechanism, and the physical pictures of them was discussed. Peak plate number would be regarded as an asymmetry index of peak, as column plate number is regarded as an efficiency index of column.

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