scholarly journals THE DEVELOPMENT OF A NEW ADSORPTION-DESORPTION DEVICE

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Ľudmila Gabrišová ◽  
Peter Peciar ◽  
Oliver Macho ◽  
Martin Juriga ◽  
Paulína Galbavá ◽  
...  
Keyword(s):  
Distilled Water ◽  
Water Mixture ◽  
Desorption Process ◽  
Water Vapour Sorption ◽  
Adsorption And Desorption ◽  
Volatile Organic ◽  
Preliminary Study ◽  
Adsorption Desorption ◽  
Granulated Activated Carbon

The aim of this work was to construct a new adsorption-desorption device based on the principle of separation of volatile organic compounds, e.g., ethanol. As an adsorbent, it is possible to use granulated activated carbon (GAC) in the adsorption and desorption process. In this study, two kinds of GACs were used and marked as GAC1 and GAC2. A particle size distribution and water vapour sorption for the selected GACs were measured. An experiment with distilled water was performed as a preliminary study of the new device’s functionality. After the determination of the time necessary for the adsorption and desorption, the experiments were carried out with a model mixture (5% v/v ethanol-water mixture), which resulted in a product with the ethanol content of 39.6 %. The main advantage of this device would be the potential competition of conventional distillation.

Interim Method for Determination of Volatile Organic Compounds in Hazardous Wastes

1984 ◽  
Vol 67 (4) ◽  
pp. 776-782
Author(s):  
Donald F Gurka ◽  
J Scott Warner ◽  
Larry E Silvon ◽  
Thomas A Bishop ◽  
Mary M Mckown
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Industrial Wastes ◽  
Hazardous Wastes ◽  
Tetraethylene Glycol ◽  
Water Mixture ◽  
Analytical Protocol ◽  
Volatile Organic ◽  
Control Procedures

Abstract An analytical protocol is presented for the determination of volatile organic compounds in hazardous wastes that are amenable to the purge-and-trap method. The protocol features a tetraethylene glycol dimethyl ether (tetraglyme) extraction of the liquid or solid waste, addition of an aliquot of the tetraglyme waste to water, and purging of the tetraglyme-water mixture with subsequent gas chromatographic/ mass spectrometric (GC/MS) analysis. The size of the tetraglyme aliquot is determined by gas chromatographic screening of a hexadecane waste extract. Quality assurance/quality control procedures are included within the analytical protocol. Spike extraction recoveries of industrial wastes obtained by following this protocol are given.

scholarly journals STUDY OF CARBON DIOXIDE ADSORPTION ON CHROMOXIDE CATALYST ON NON-STATIONARY CONCENTRATIONS

2018 ◽  
Vol 61 (7) ◽  
pp. 37 ◽  
Author(s):  
Nikolay I. Kol'tsov ◽  
Vladislav Kh. Fedotov
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Chemical Kinetics ◽  
Carbon Dioxide Adsorption ◽  
Dissociative Mechanism ◽  
Simple Method ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Additional Information ◽  
Adsorption Desorption

Investigation of the regularities of chemical processes, not only near but also far from the stationary state, gives additional information on their mechanisms. In this paper, we present a new method for estimating rate constants of adsorption-desorption processes from the experimentally measured values of the nonstationary concentrations of an adsorbed substance, based on calculating the instantaneous rates of the adsorption (or desorption) process. This method allows to connect unknown kinetic parameters of adsorption (desorption) of a substance on the catalyst surface for various most probable assumed mechanisms with the calculated values of the instantaneous rates of adsorption-desorption processes. As a consequence, the method makes it possible to solve two types of inverse problems of chemical kinetics: calculate point and interval values of rates constants of adsorption and desorption; determine the most likely mechanism from several proposed mechanisms of implementation of these processes. Using this method, point and interval values of the rates constants of adsorption and desorption of carbon dioxide were determined on the base of nonstationary experimental data on adsorption on the assumption of carbon dioxide adsorption on a chromoxide catalyst to three proposed mechanisms: linear, bimolecular and dissociative. Based on the results of calculations, the corresponding non-stationary dependences of carbon dioxide adsorption were restored, which were compared with the experimental data. The obtained results confirm that the previously established dissociative mechanism of adsorption of carbon dioxide on the chromoside catalyst is the most probable. The developed simple method does not require the use of complex optimization calculations and can be used to solve the inverse problem of chemical kinetics associated with the determination of mechanisms and the estimation of the rates constants of adsorption and desorption of substances on various catalysts.Forcitation:Kol’tsov N.I., Fedotov V.Kh. Study of carbon dioxide adsorption on chromoxide catalyst on non-stationary concentrations. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 37-42

Characterising the Differences between the Adsorption and Desorption Processes in a Desiccant Layer by Detailed Numerical Modelling

2012 ◽  
Vol 326-328 ◽  
pp. 690-695
Author(s):  
C.R. Ruivo ◽  
J.J. Costa ◽  
A.R. Figueiredo
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Channel Wall ◽  
Water Adsorption ◽  
Sorption Isotherms ◽  
Transfer Coefficients ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Adsorption Desorption ◽  
Simultaneous Heat

In this paper, the performance of a channel element of a hygroscopic matrix is evaluated by detailed numerical modeling. The adopted physical model takes into account the gas-side and solid-side resistances to heat and mass transfer, as well as the simultaneous heat and mass transfer occurring simultaneously with the water adsorption/desorption process in the desiccant porous channel wall domain. The desiccant medium is silica gel RD, the equilibrium being characterized by sorption isotherms. Appropriate convective transfer coefficients are taken into account for the calculation of the heat and mass transfer phenomena between the airflow and the channel wall. The response of the channel element to a step change in the airflow states is simulated, the results enabling the investigation of some differences between the adsorption and desorption processes.

scholarly journals The Use of Starch Drying Kinetics Curves for Experimental Determination of Its Specific Surface Area

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5508
Author(s):  
Marzena Włodarczyk-Stasiak ◽  
Artur Mazurek
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Water Vapour ◽  
Specific Surface Area ◽  
Sorption Isotherms ◽  
Water Vapour Sorption ◽  
Vapour Sorption ◽  
Drying Curves ◽  
Adsorption Desorption

The most popular method for the calculation of specific surface area is its determination from water vapour sorption isotherms. The study presented here has been designed for the purpose of optimisation and selection of the conditions of drying so as to allow the determination of specific surface area from plotted curves of the drying process. The results indicate that drying curves can be used as the basis for the determination of specific surface area, the values of which do not differ statistically significantly (α = 0.05) from those determined from isotherms of water vapour sorption (adsorption/desorption).

Study on Adsorption and Desorption of Suspended Sediments to Phosphorus in Ganjiang River

2012 ◽  
Vol 599 ◽  
pp. 669-672 ◽  
Author(s):  
Qiu Lin Ouyang ◽  
Gui Qing Gao ◽  
Su Su Liu ◽  
Xiao Ling Shi ◽  
Hai Yan Ju
Keyword(s):  
Suspended Sediments ◽  
Sediment Concentration ◽  
Isothermal Adsorption ◽  
Phosphorus Adsorption ◽  
Kinetic Experiment ◽  
Desorption Process ◽  
Desorption Kinetic ◽  
Adsorption And Desorption ◽  
Phosphorus Desorption ◽  
Adsorption Desorption

Based on isothermal adsorption experiment and adsorption/desorption kinetic experiment,the adsorption and desorption characteristics of suspended sediments in Ganjiang River to phophorus was studied.The results show the phosphorus adsorption of sediment reaches balance basically in 2~4h; the adsorption capacity is increased with the increment of the initial concentration of phosphorus,and decreased with the increment of sediment conentration. The isothermal adsorption of phosphorus by sediment can be fitted preferably by Langmuir and Freundlic model. The adsorption and desorption process can be fitted by Langmuir equation.The phosphorus desorption of sediment reaches balance basically in about 14h. The phosphorus desorption capacity of sediment is decreased with the increment of sediment concentration.

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