Extra-Column Effects in Determination of Rate Parameters by the Chromatographic Method

1996 ◽  
Vol 61 (6) ◽  
pp. 844-855 ◽  
Author(s):  
Olga Šolcová ◽  
Petr Schneider
Keyword(s):  
Chromatographic Method ◽  
Dynamic Method ◽  
Axial Dispersion ◽  
Transport Parameters ◽  
Porous Particles ◽  
Loop Detector ◽  
Single Pellet ◽  
Set Up ◽  
Extra Column Effects

It was shown that the sampling loop, detector and connecting elements in the chromatographic set-up for determination of transport parameters by the dynamic method significantly influence the response peaks from columns packed with porous or nonporous particles. A method, based on the use of convolution theorem, was developed which can take these effects into account. The applicability of this method was demonstrated on the case of axial dispersion in a single-pellet-string column (SPSR) packed with nonporous particles. It is possible to handle also responses from columns packed with porous particles by a similar procedure.

Determination of the aeration capacity of bubble columns by dynamic method. The influence of axial dispersion and of the start-up period

1979 ◽  
Vol 44 (9) ◽  
pp. 2583-2597 ◽  
Author(s):  
Václav Linek ◽  
Jiří Stejskal ◽  
Jiří Sinkule ◽  
Václav Vacek
Keyword(s):  
Dynamic Method ◽  
Dispersion Model ◽  
Oxygen Electrode ◽  
Axial Dispersion ◽  
Bubble Columns ◽  
Oxygen Probe ◽  
Start Up ◽  
Axial Dispersion Model ◽  
Aeration Capacity

A dynamic method for the determination of volumetric mass transfer coefficient of oxygen, kLa, in bubble columns using an oxygen electrode was derived on the basis of a liquid phase axial dispersion model The influence of aeration startup was studied assuming that the kLa value is position and time dependent. The conditions are defined under which the influence of aeration startup and of axial mixing of the liquid upon the steady state kLa value is negligible. A critical assessment has been made of various methods proposed for evaluation of oxygen probe responses.

Fifty Years of Moment Technique for Dynamic Analysis of Chemical Reactor Parameters

2019 ◽  
Vol 17 (5) ◽  
Author(s):  
Gülşen Doğu ◽  
Timur Doğu
Keyword(s):  
Dynamic Analysis ◽  
Reaction Rate ◽  
Chemical Reactor ◽  
Axial Dispersion ◽  
Moment Analysis ◽  
Transport Parameters ◽  
Transfer Coefficients ◽  
Engineering Research ◽  
Single Pellet ◽  
Fixed Beds

Abstract Moment technique has been extensively used for the evaluation of the rate and equilibrium parameters in chemical reactors and also in adsorption vessels, for about five decades. Adsorption and reaction rate parameters, as well as axial dispersion constants, effective diffusivities within porous catalysts and heat and mass transfer coefficients were shown to be effectively evaluated by analyzing the moments of the response peaks, which could be obtained from pulse-response experiments performed in a reaction/adsorption vessel. A detailed review of chromatographic processes, involving moment analysis of adsorption equilibrium and rate constants in fixed beds, dynamic analysis of batch adsorbers, moment analysis of fluidized bed, slurry and trickle bed reactors are reported in this manuscript. Applications of the single-pellet moment technique, which was developed for the effective investigation of intrapellet rate and equilibrium processes, by eliminating the contributions of axial dispersion and external transport parameters, are comprehensively discussed. Recent studies for the analysis of reaction rate parameters using the TAP reactor approach, use of single pellet system for the investigation of catalytic and non-catalytic solid-gas reactions and extension of the moment technique to non-linear systems opened new pathways in reaction engineering research.

scholarly journals New ion-chromatography method for detection of chlorite, chlorate, and bromate in drinking water

2020 ◽  
Vol 2 (2) ◽  
pp. 49-55
Author(s):  
Iuliana Paun ◽  
Vasile Ion Iancu ◽  
Florentina Laura Chiriac ◽  
Nicoleta Vasilache ◽  
Florinela Pirvu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Ion Chromatography ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Chromatography Method ◽  
Column Temperature ◽  
Drinking Waters ◽  
Target Analytes ◽  
Set Up

A direct ion chromatographic method for the determination of chlorite, chlorate, and bromate in the presence of fluoride, chloride, nitrate, nitrite, and bromide in treated drinking waters was described. Separation of target analytes was achieved using an AS19-HC analytical column (250 mm x 4 mm), AG 19- HC guard column (50 mm x 4 mm), and KOH 25 mmol/L as mobile phase. Inorganic analytes were eluted using a flow rate of 1 mL/min. The column temperature was set up and maintained at 300C. The analyte ions were quantified using a suppressed conductivity detector.

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