A revisit and review of experimental variables affecting chromatographic organics - polydimethylsiloxane interactions
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Absorption , Liquid loading , Polymers , Specific retention volume , Gas-liquid chromatography , Polydimethylsiloxane
- Type: Article
- Identifier: uj:4897 , ISSN 2277 – 4394 , http://hdl.handle.net/10210/12990
- Description: The effect of experimental variables namely liquid loading, sample size, temperature, vapour pressure and carrier gas flow rate on gas-liquid chromatographic technique (GLC) with polydimethylsiloxane (PDMS) as the stationary phase...
- Full Text:
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Absorption , Liquid loading , Polymers , Specific retention volume , Gas-liquid chromatography , Polydimethylsiloxane
- Type: Article
- Identifier: uj:4897 , ISSN 2277 – 4394 , http://hdl.handle.net/10210/12990
- Description: The effect of experimental variables namely liquid loading, sample size, temperature, vapour pressure and carrier gas flow rate on gas-liquid chromatographic technique (GLC) with polydimethylsiloxane (PDMS) as the stationary phase...
- Full Text:
Effect of temperature on specific retention volumes of selected volatile organic compounds using the gas-liquid chromatographic technique revisited
- Muzenda, Edison, Afolabi, Ayo S.
- Authors: Muzenda, Edison , Afolabi, Ayo S.
- Date: 2010
- Subjects: Specific retention volumes , Volatile organic compounds , Polydimethylsiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:4711 , http://hdl.handle.net/10210/10957
- Description: This paper is a continuation of our interest in the influence of temperature on specific retention volumes and the resulting infinite dilution activity coefficients. This has a direct effect in the design of absorption and stripping columns for the abatement of volatile organic compounds. The interaction of 13 volatile organic compounds (VOCs) with polydimethylsiloxane (PDMS) at varying temperatures was studied by gas liquid chromatography (GLC). Infinite dilution activity coefficients and specific retention volumes obtained in this study were found to be in agreement with those obtained from static headspace and group contribution methods by the authors as well as literature values for similar systems. Temperature variation also allows for transport calculations for different seasons. The results of this work confirm that PDMS is well suited for the scrubbing of VOCs from waste gas streams.
- Full Text:
- Authors: Muzenda, Edison , Afolabi, Ayo S.
- Date: 2010
- Subjects: Specific retention volumes , Volatile organic compounds , Polydimethylsiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:4711 , http://hdl.handle.net/10210/10957
- Description: This paper is a continuation of our interest in the influence of temperature on specific retention volumes and the resulting infinite dilution activity coefficients. This has a direct effect in the design of absorption and stripping columns for the abatement of volatile organic compounds. The interaction of 13 volatile organic compounds (VOCs) with polydimethylsiloxane (PDMS) at varying temperatures was studied by gas liquid chromatography (GLC). Infinite dilution activity coefficients and specific retention volumes obtained in this study were found to be in agreement with those obtained from static headspace and group contribution methods by the authors as well as literature values for similar systems. Temperature variation also allows for transport calculations for different seasons. The results of this work confirm that PDMS is well suited for the scrubbing of VOCs from waste gas streams.
- Full Text:
Organics - PDMS interactions : a phase equilibrium study
- Haiyambo, Gerson H., Muzenda, Edison
- Authors: Haiyambo, Gerson H. , Muzenda, Edison
- Date: 2012
- Subjects: Absorption , Functional groups , Vapour-liquid equilibrium , Polydimethylsiloxane
- Type: Article
- Identifier: uj:6041 , http://hdl.handle.net/10210/10441
- Description: The vapour-liquid equilibrium of 80 organics in Polydimethylsiloxane (PDMS) were predicted using the UNIFAC Lynby, Larsen et al., 1987 [1]. The organics were selected from 8 family functional groups namely cycloalkanes, aldehydes, alcohols, carboxylic acids, esters, ethers, thiols and amines. PDMS showed great absorption affinity for all organics in particular carboxylic acids and ethers.
- Full Text:
- Authors: Haiyambo, Gerson H. , Muzenda, Edison
- Date: 2012
- Subjects: Absorption , Functional groups , Vapour-liquid equilibrium , Polydimethylsiloxane
- Type: Article
- Identifier: uj:6041 , http://hdl.handle.net/10210/10441
- Description: The vapour-liquid equilibrium of 80 organics in Polydimethylsiloxane (PDMS) were predicted using the UNIFAC Lynby, Larsen et al., 1987 [1]. The organics were selected from 8 family functional groups namely cycloalkanes, aldehydes, alcohols, carboxylic acids, esters, ethers, thiols and amines. PDMS showed great absorption affinity for all organics in particular carboxylic acids and ethers.
- Full Text:
Chromatographic detectors and column holdup for organics-PDMS systems
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polydimethylsiloxane , Column hold-ups , Gas chromatographic detectors
- Type: Article
- Identifier: uj:4688 , ISBN 978-93-82242-16-1 , http://hdl.handle.net/10210/10477
- Description: Gas chromatographic detector types and application, as well carrier gas flow rate and column hold-up measurements are discussed in this paper. The flame ionization and hot wire detectors are discussed in detail. The measurement of carrier gas flow rate using a soap film bubble flow meter is explained. Column hold-ups for 4 poly(dimethylsiloxane) packed columns were measured using the homologous series method.
- Full Text:
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polydimethylsiloxane , Column hold-ups , Gas chromatographic detectors
- Type: Article
- Identifier: uj:4688 , ISBN 978-93-82242-16-1 , http://hdl.handle.net/10210/10477
- Description: Gas chromatographic detector types and application, as well carrier gas flow rate and column hold-up measurements are discussed in this paper. The flame ionization and hot wire detectors are discussed in detail. The measurement of carrier gas flow rate using a soap film bubble flow meter is explained. Column hold-ups for 4 poly(dimethylsiloxane) packed columns were measured using the homologous series method.
- Full Text:
Absorption of volatile organic compounds into polydimethylsiloxane : phase equilibrium computation at infinite dilution
- Muzenda, Edison, Mateescu, Corina M.
- Authors: Muzenda, Edison , Mateescu, Corina M.
- Date: 2011
- Subjects: Volatile organic compounds , Polydimethylsiloxane , UNIFAC group contribution methods
- Type: Article
- Identifier: uj:5318 , ISSN 2010-3778 , http://hdl.handle.net/10210/8183
- Description: Group contribution methods such as the UNIFAC are very useful to researchers and engineers involved in synthesis, feasibility studies, design and optimization of separation processes. They can be applied successfully to predict phase equilibrium and excess properties in the development of chemical and separation processes. The main focus of this work was to investigate the possibility of absorbing selected volatile organic compounds (VOCs) into polydimethylsiloxane (PDMS) using three selected UNIFAC group contribution methods. Absorption followed by subsequent stripping is the predominant available abatement technology of VOCs from flue gases prior to their release into the atmosphere. The original, modified and effective UNIFAC models were used in this work. The thirteen selected VOCs that have been considered in this research are: pentane, hexane, heptanes, trimethylamine, toluene, xylene, cyclohexane, butyl acetate, diethyl acetate, chloroform, acetone, ethyl methyl ketone and isobutyl methyl ketone. The computation was done for solute VOC concentration of 8.55x10-8 which is well in the infinite dilution region. The results obtained in this study compare very well with those published in literature obtained through both measurements and predictions. The phase equilibrium obtained in this study show that PDMS is a good absorbent for the removal of VOCs from contaminated air streams through physical absorption.
- Full Text:
- Authors: Muzenda, Edison , Mateescu, Corina M.
- Date: 2011
- Subjects: Volatile organic compounds , Polydimethylsiloxane , UNIFAC group contribution methods
- Type: Article
- Identifier: uj:5318 , ISSN 2010-3778 , http://hdl.handle.net/10210/8183
- Description: Group contribution methods such as the UNIFAC are very useful to researchers and engineers involved in synthesis, feasibility studies, design and optimization of separation processes. They can be applied successfully to predict phase equilibrium and excess properties in the development of chemical and separation processes. The main focus of this work was to investigate the possibility of absorbing selected volatile organic compounds (VOCs) into polydimethylsiloxane (PDMS) using three selected UNIFAC group contribution methods. Absorption followed by subsequent stripping is the predominant available abatement technology of VOCs from flue gases prior to their release into the atmosphere. The original, modified and effective UNIFAC models were used in this work. The thirteen selected VOCs that have been considered in this research are: pentane, hexane, heptanes, trimethylamine, toluene, xylene, cyclohexane, butyl acetate, diethyl acetate, chloroform, acetone, ethyl methyl ketone and isobutyl methyl ketone. The computation was done for solute VOC concentration of 8.55x10-8 which is well in the infinite dilution region. The results obtained in this study compare very well with those published in literature obtained through both measurements and predictions. The phase equilibrium obtained in this study show that PDMS is a good absorbent for the removal of VOCs from contaminated air streams through physical absorption.
- Full Text:
Phase equilibrium of volatile organic compounds in silicon oil using the UNIFAC procedure : an estimation
- Muzenda, Edison, Simate, Geoffrey S., Belaid, Mohamed, Ntuli, Freeman, Mollagee, Mansoor
- Authors: Muzenda, Edison , Simate, Geoffrey S. , Belaid, Mohamed , Ntuli, Freeman , Mollagee, Mansoor
- Date: 2011
- Subjects: Phase equilibrium , Thermodynamic models , Volatile organic compounds , Polydimethylsiloxane , Silicon oil
- Type: Article
- Identifier: uj:4699 , http://hdl.handle.net/10210/10934
- Description: This paper focuses on the phase equilibrium of volatile organic compounds in silicon oil chemically known as PDMS (polydimethylsiloxane) at infinite dilution. Measurements can be expensive and time consuming, hence the need for thermodynamic models which allow the calculation of the phase equilibrium behavior using a limited number of experimental data. The objective of this study was to predict infinite dilution activity coefficients of selected VOCs (volatile organic compounds) in PDMS using the Original UNIFAC model. The predicted results show that PDMS can be used to abate volatile organic compounds from contaminated air streams. The results obtained in this work are comparable to those obtained by the same authors through measurements such as the static headspace and the dynamic gas liquid chromatographic techniques as well as other literature. Although the UNIFAC group contribution method over estimate the infinite dilution activity coefficients, the results of this work may be applied in preliminary phases of process design, simulation and feasibility studies.
- Full Text:
- Authors: Muzenda, Edison , Simate, Geoffrey S. , Belaid, Mohamed , Ntuli, Freeman , Mollagee, Mansoor
- Date: 2011
- Subjects: Phase equilibrium , Thermodynamic models , Volatile organic compounds , Polydimethylsiloxane , Silicon oil
- Type: Article
- Identifier: uj:4699 , http://hdl.handle.net/10210/10934
- Description: This paper focuses on the phase equilibrium of volatile organic compounds in silicon oil chemically known as PDMS (polydimethylsiloxane) at infinite dilution. Measurements can be expensive and time consuming, hence the need for thermodynamic models which allow the calculation of the phase equilibrium behavior using a limited number of experimental data. The objective of this study was to predict infinite dilution activity coefficients of selected VOCs (volatile organic compounds) in PDMS using the Original UNIFAC model. The predicted results show that PDMS can be used to abate volatile organic compounds from contaminated air streams. The results obtained in this work are comparable to those obtained by the same authors through measurements such as the static headspace and the dynamic gas liquid chromatographic techniques as well as other literature. Although the UNIFAC group contribution method over estimate the infinite dilution activity coefficients, the results of this work may be applied in preliminary phases of process design, simulation and feasibility studies.
- Full Text:
A review of polydimethylsiloxane - volatile organic compounds interactions
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polymers , Volatile organic compounds , Polydimethylsiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:4682 , ISBN 978-93-82242-07-9 , http://hdl.handle.net/10210/10455
- Description: This paper is a review on the interactions of certain volatile organic compounds with polydimethylsiloxane using the gas liquid chromatographic technique (GLC). The interactions reviewed here were studied in the form of specific retention volumes. Only single stationary phases were considered in this review. For similar systems, the retention data agrees very well. This review has shown that the GLC is a rapid and convenient method to obtain thermodynamic data for polymeric systems. This work is very useful in the determination of phase equilibrium in form of infinite dilution activity coefficients necessary for the design of absorption and stripping columns for the abatement of volatile organic compounds from contaminated air streams.
- Full Text:
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polymers , Volatile organic compounds , Polydimethylsiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:4682 , ISBN 978-93-82242-07-9 , http://hdl.handle.net/10210/10455
- Description: This paper is a review on the interactions of certain volatile organic compounds with polydimethylsiloxane using the gas liquid chromatographic technique (GLC). The interactions reviewed here were studied in the form of specific retention volumes. Only single stationary phases were considered in this review. For similar systems, the retention data agrees very well. This review has shown that the GLC is a rapid and convenient method to obtain thermodynamic data for polymeric systems. This work is very useful in the determination of phase equilibrium in form of infinite dilution activity coefficients necessary for the design of absorption and stripping columns for the abatement of volatile organic compounds from contaminated air streams.
- Full Text:
On organics – polydimethylsiloxane interactions : influence of experimental variables
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polymers , Polydimethylsiloxane
- Type: Article
- Identifier: uj:6047 , ISBN 978-93-82242-07-9 , http://hdl.handle.net/10210/10456
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Muzenda, Edison
- Date: 2012
- Subjects: Polymers , Polydimethylsiloxane
- Type: Article
- Identifier: uj:6047 , ISBN 978-93-82242-07-9 , http://hdl.handle.net/10210/10456
- Description: Please refer to full text to view abstract
- Full Text:
Measurement of infinite dilution activity coefficients of selected environmentally important volatile organic compounds in polydimethylsiloxane using gas – liquid chromatography
- Muzenda, Edison, Belaid, M., Ntuli, Freeman
- Authors: Muzenda, Edison , Belaid, M. , Ntuli, Freeman
- Date: 2010
- Subjects: Thermodynamics , Polydimethylsiloxane , Activity coefficients , Volatile organic compounds absorption
- Type: Article
- Identifier: uj:5306 , http://hdl.handle.net/10210/5284
- Description: Silicon oil chemically known as polydimethylsiloxane (PDMS) is a high boiling point solvent highly suitable for volatile organic compounds (VOCs) absorption. In order to use PDMS as an absorption solvent for a specific waste gas problem, it is important to determine the infinite dilution activity coefficients of the VOCs to be separated with PDMS. This work reports activity coefficients at infinite dilution of 13 VOCs in polydimethysiloxane determined by the dynamic gas liquid chromatographic technique. The measurements were carried out at various temperatures (i.e, 303.15, 313.15, 323.15., 333.15, 353.15, 373.15, 393.15 and 423.15K). Four PDMS polymers with average molecular weight ranging from 760 to 13 000 were used as solvents. A control column packed by Perkin Elmer to our specifications was used to validate the coating and packing methods. Flow rate dependence of the elution peaks was also investigated by varying it from 10 – 50 ml/min. Precision was improved by reproducing the results using columns with different liquid loading, thus also studying the retention mechanism. The results compare well with the data from previous work using simple headspace and UNIFAC predictions and literature values. The successful comparison gives an indication of the GLC as a rapid, simple and accurate method for studying the thermodynamics of the interaction of a volatile solute with a non volatile solvent.
- Full Text:
- Authors: Muzenda, Edison , Belaid, M. , Ntuli, Freeman
- Date: 2010
- Subjects: Thermodynamics , Polydimethylsiloxane , Activity coefficients , Volatile organic compounds absorption
- Type: Article
- Identifier: uj:5306 , http://hdl.handle.net/10210/5284
- Description: Silicon oil chemically known as polydimethylsiloxane (PDMS) is a high boiling point solvent highly suitable for volatile organic compounds (VOCs) absorption. In order to use PDMS as an absorption solvent for a specific waste gas problem, it is important to determine the infinite dilution activity coefficients of the VOCs to be separated with PDMS. This work reports activity coefficients at infinite dilution of 13 VOCs in polydimethysiloxane determined by the dynamic gas liquid chromatographic technique. The measurements were carried out at various temperatures (i.e, 303.15, 313.15, 323.15., 333.15, 353.15, 373.15, 393.15 and 423.15K). Four PDMS polymers with average molecular weight ranging from 760 to 13 000 were used as solvents. A control column packed by Perkin Elmer to our specifications was used to validate the coating and packing methods. Flow rate dependence of the elution peaks was also investigated by varying it from 10 – 50 ml/min. Precision was improved by reproducing the results using columns with different liquid loading, thus also studying the retention mechanism. The results compare well with the data from previous work using simple headspace and UNIFAC predictions and literature values. The successful comparison gives an indication of the GLC as a rapid, simple and accurate method for studying the thermodynamics of the interaction of a volatile solute with a non volatile solvent.
- Full Text:
- «
- ‹
- 1
- ›
- »