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Journal Details
Format
Journal
eISSN
1899-4741
ISSN
1509-8117
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

Volume 13 (2011): Issue 3 (September 2011)

Journal Details
Format
Journal
eISSN
1899-4741
ISSN
1509-8117
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

13 Articles
Open Access

Single-walled carbon nanotubes fractionation via electrophoresis

Published Online: 05 Oct 2011
Page range: 1 - 4

Abstract

Single-walled carbon nanotubes fractionation via electrophoresis

This work presents the influence of the sonication time on the efficiency of the metallic/semiconducting (M/S) fractionation of diazonium salt functionalized single-walled carbon nanotubes (SWCNTs) via free solution electrophoresis (FSE) method. The SWCNTs synthesized via laser ablation were purified from amorphous carbon and catalyst particles through high vacuum annealing and subsequent refluxing processes in aqua regia solutions, respectively. The purified material was divided into two batches. The SWCNTs samples were dispersed in 1% SDS solution in ultrasound bath for 2 and 12 hours. Both dispersed SWCNTs samples were functionalized with p-aminobenzoic acid diazonium salt and fractionated via free solution electrophoresis method. Afterwards, the fractionated samples were recovered, purified from surfactant/functionalities by annealing and investigated via UV-Vis-NIR optical absorption spectroscopy (OAS). The efficiency of the fractionation process was estimated through the comparison of the van Hove singularities (vHS) presented in the obtained fractions to the starting SWCNTs.

Keywords

  • SWCNTs
  • diazonium salts
  • fractionation
  • electrophoresis
Open Access

Catalytic synthesis of warfarin acetals by using different heteropolyacid catalysts

Published Online: 05 Oct 2011
Page range: 5 - 11

Abstract

Catalytic synthesis of warfarin acetals by using different heteropolyacid catalysts

In this research, we report on the synthesis of warfarin acetals by using Preyssler's anion, [NaP5W30O110]-14 and heteropolyacids (HPAs) catalysts. This reaction was performed using methanol and ethanol at reflux temperature conditions. Under these conditions we have excellent yields and high selectivity. Preyssler heteropolyacid catalyst were easily recycled recovery and reused without the loss of its catalytic activities. The synthesis of warfarin acetals has been achieved using the catalytic amounts of green, inexpensive and eco-friendly Keggin types heteropolyacids. The products were obtained in high yields.

Keywords

  • Heteropolyacid
  • Preyssler
  • Catalyst
  • Warfarin
  • Cyclic acetals
Open Access

Tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation

Published Online: 05 Oct 2011
Page range: 12 - 17

Abstract

<italic>Tert</italic>-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation

A series of seven substituted tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids has been synthesized, isolated, spectroscopically and structurally elucidated. An influence of the substituents on the spectroscopic characteristics and conformations is discussed using the data of the linear-polarized IR- (IR-LD), UV-spectroscopy and 1H-NMR. Theoretical quantum chemical calculations are carried out, with a view to explaining and supporting the experimental optical properties and the electronic structure. The stereoselective synthesis of the corresponding diastereoisomers is optimized, thus giving good yields (62-72%) and purity of the compounds

Keywords

  • -butyl esters of 2,3-diaryl-3-arylaminopropanoic acids
  • optical properties
  • quantum chemistry
Open Access

Environmental Impact Assessment of Biogas Stations in the Czech Republic

Published Online: 05 Oct 2011
Page range: 18 - 22

Abstract

Environmental Impact Assessment of Biogas Stations in the Czech Republic

The article summarizes the authors' experience with environmental impact assessment in the branch of biogas plants. The introductory part of the paper describes the legislative obligations of the Czech Republic concerning the fulfilment of the European Union's limits as for the utilization of renewable energy resources. The next parts of the paper deal with an impact analysis of biogas plants on the environment. The final part of the paper deals with the experience concerning the implementation of the environmental impact assessment process in the field of biogas plants in the Czech Republic.

Keywords

  • Biogas station
  • environmental impact assessment
  • odour
Open Access

Radioactivity of some building and raw materials used in Croatia

Published Online: 05 Oct 2011
Page range: 23 - 27

Abstract

Radioactivity of some building and raw materials used in Croatia

In the present study, the activity concentrations of 226Ra, 232Th, 40K in some building and raw materials used in Croatia were measured by using a gamma-ray spectrometer with the HPGe detector. The average activity concentrations of the studied different building and raw materials ranged from 11.6 ± 1.7 (concrete) to 251.2 ± 25.7 Bqkg-1 (GBFS), 14.0 ± 2.7 (concrete) to 54.4 ± 8.3 (coal fly ash) and 147.2 ± 19.0 (concrete) to 773.7 ± 82.0 Bqkg-1 (tuff) for 226Ra, 232Th and 40K, respectively. Radium equivalent activity, activity concentration index, absorbed gamma dose rate indoor due to the external exposure and corresponding annual effective dose were determined to estimate the exposure risk arising due to the use of these building and raw materials.

Keywords

  • Radioactivity
  • Building materials
  • Fly ash
  • Gamma-ray spectrometer
  • Annual effective dose
Open Access

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts

Published Online: 05 Oct 2011
Page range: 28 - 36

Abstract

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts

In this work, catalytic activity and stability of Cu/Y5 and Cu/ZSM5 zeolites in phenol oxidation with hydrogen peroxide were examined. The catalyst samples were prepared by the ion exchange method of the protonic form of commercial zeolites. The catalysts were characterized by the powder X-ray diffraction (XRD), AAS, while the adsorption techniques were used to measure the specific surface area.

The thermal programmed desorption of NH3 (NH3-TPD) was used for measuring the total number of acid sites formed on the surface of zeolites.

Catalytic performance of the prepared samples was monitored in terms of phenol, hydrogen peroxide and total organic carbon (TOC) conversion, by-product distribution and a degree of copper leached into the aqueous solution.

It was found that the activity of Cu/Y5 catalyst was generally higher than that of Cu/ZSM5 and that unlike Cu/ZSM5, Cu/Y5 catalyzed phenol oxidation more completely.

Keywords

  • waste water treatment
  • phenol oxidation
  • hydrogen peroxide
  • catalysts
  • Cu/ZSM5
  • Cu/Y5
Open Access

COD reduction studies of paper mill effluent using a batch recirculation electrochemical method

Published Online: 05 Oct 2011
Page range: 37 - 41

Abstract

COD reduction studies of paper mill effluent using a batch recirculation electrochemical method

The conventional method of treating pulp and paper mill effluent involves the biological oxidation by bacterial action of aerobic and anaerobic conditions and aerobic lagooning method, which are less efficiency of removing COD. To overcome the drawbacks of the existing treatment process, in the present work an attempt has been made to study the electro oxidative destruction of the pulp and paper mill effluent using an electrochemical method and the effect of various parameters such as concentration of supporting electrolytes, current densities, flow rates of electrolyte and reservoir volumes of the effluent were conducted. From the experimental results it is observed that the rate of reduction of COD of the effluent increased with an increase in the supporting electrolyte (sodium chloride) concentration, current density where as it decreased with increase in the reservoir volume and the flow rate of electrolyte. The residence time distributions studies have also been conducted to study the behavior of the electrochemical reactor.

Keywords

  • effluent treatment
  • residence time distributions
  • electrochemical reactor
  • Pulp and Paper mill effluent
Open Access

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application

Published Online: 05 Oct 2011
Page range: 42 - 46

Abstract

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application

The results of the study on the reactions of melamine cyanurate with ethylene carbonate were presented. As a result of the reactions, polyetherols containing thermostabile 1,3,5-triazine and perhyroxo-1,3,5-triazine rings in their structure were obtained. Basic physical properties such as density, viscosity, hydroxyl number, weight changes were measured. The polyetherols were applied as a polyol component to receiving of thermoresistant polyurethane foams. Some of the properties of the obtained foams were investigated. The value of the apparent density is between 51 and 71 kg/m3, compressive strength 222-356 kPa and the content of the open pores between 14-33%. Thermal resistance was also studied by means of the TGA method. It was found that oxygen index of the selected compositions is between 20-22%.

Keywords

  • melamine cyanurate
  • ethylene carbonate
  • polyetherols
  • polyurethane foams
Open Access

Modified halloysite as a filler for epoxy resins

Published Online: 05 Oct 2011
Page range: 47 - 52

Abstract

Modified halloysite as a filler for epoxy resins

The modification methods of halloysite and further applications of the modified mineral as a filler for epoxy resins have been presented. The advantage of ultrasound treatment prior to chemical modification with an organic compound in order to obtain a hybrid filler was confirmed. The analysis of the composites obtained with the use of the modified halloysite (3-5 wt.% range) as a filler for epoxy resins indicates an improved interphase interaction and mechanical properties in comparison to the composites based on neat halloysite.

Keywords

  • layered-tubular mineral
  • chemical modification
  • modification with ultrasounds
  • fillers
  • filling of epoxy resins
  • mechanical and thermal properties
Open Access

Present and prospective leather industry waste disposal

Published Online: 05 Oct 2011
Page range: 53 - 55

Abstract

Present and prospective leather industry waste disposal

In this paper general characteristics of the main leather industry waste regarding its amount reduction by thermal treatment have been presented. Both the tannery solid wastes and the sludge contain organic substances. Their energy value is more than 50% higher in comparison to hard coal (nominally 20 MJ/kg as dry material). Up to now, the considerable amounts of energy are not recovered; leather wastes are predominantly on landfill. Implementation of a comprehensive thermal method for tannery solid waste and sludge utilization can permit to solve the waste disposal problem by effective neutralization of all of the waste. Moreover, it should bring economic benefits associated with steam or hot water production and landfill tax avoiding. The study is oriented towards the practical application.

Keywords

  • leather industry
  • tannery waste
  • sewage sludge
  • odor
  • waste treatment
  • thermal neutralization
Open Access

Separation of volatile compounds from fermentation broth by membrane distillation

Published Online: 05 Oct 2011
Page range: 56 - 60

Abstract

Separation of volatile compounds from fermentation broth by membrane distillation

The diluted ethanol solutions and fermentation broth (Saccharomyces cerevisiae) were separated by membrane distillation (MD). Hydrophobic macroporous (pore size 0.2 μm) capillary polypropylene membranes, Accurel PP V8/2 HF and Accurel PP S6/2, were used for these studies. The MD process can be successfully applied to remove the volatile components from the fermentation broth. Besides ethanol, propionic and acetic acids were moved from the broth to the distillate. Therefore, the course of the fermentation carried out in a membrane distillation bioreactor considerably accelerate its rate and increase the efficiency by a selective removal of fermentation products. It was found that the broth subjected to the separation did not affect the hydrophobic properties of the polypropylene membrane assembled in the MD modules.

Keywords

  • fermentation
  • ethanol
  • membrane distillation
Open Access

Studies of properties of polypropylene/halloysite composites

Published Online: 05 Oct 2011
Page range: 61 - 65

Abstract

Studies of properties of polypropylene/halloysite composites

The results of the studies on the synthesis, mechanical and thermal properties of polypropylene composites with various amount of halloysite filler are presented. Halloysite (HNT) belongs to the silica type characterized by a two-layer 1:1 structure. This work was aimed to develop a method for the modification of halloysite in its prime use as a filler for polypropylene by extrusion. The composites contain 1, 3, 5 and 7 wt.% of HNT. The degree of crystallinity of the composites decrease with increasing halloysite content. The results confirm the expectations that composites of interesting physicochemical, mechanical and thermal properties can be obtained. The mechanical properties studied show that the filler modification method used leads to the synthesis of polymer composites of improved thermal and mechanical properties.

Keywords

  • polypropylene
  • composites
  • powder filler
  • halloysite
  • mechanical
  • thermal properties
  • morphology of polymeric materials
  • extrusion
  • injection
Open Access

The investigation of ethanol separation by the membrane distillation process

Published Online: 05 Oct 2011
Page range: 66 - 69

Abstract

The investigation of ethanol separation by the membrane distillation process

Separation of ethanol from solutions with different concentrations in a BIOTRON bioreactor integrated with the direct contact membrane distillation system has been investigated. The experiments were carried out using immersed, capillary polypropylene membranes. The permeability of the membrane at the feed inlet temperatures of 308, 318 and 333K was determined. The permeate and ethanol flux was strongly affected by the vapour pressure which increased with the feed temperature and it was also associated with ethanol concentration in the feed. It was found that the membrane distillation can be successfully applied for the separation of volatile components such as ethanol.

Keywords

  • membrane distillation
  • bioreactor
  • ethanol
  • immersed capillary membranes
13 Articles
Open Access

Single-walled carbon nanotubes fractionation via electrophoresis

Published Online: 05 Oct 2011
Page range: 1 - 4

Abstract

Single-walled carbon nanotubes fractionation via electrophoresis

This work presents the influence of the sonication time on the efficiency of the metallic/semiconducting (M/S) fractionation of diazonium salt functionalized single-walled carbon nanotubes (SWCNTs) via free solution electrophoresis (FSE) method. The SWCNTs synthesized via laser ablation were purified from amorphous carbon and catalyst particles through high vacuum annealing and subsequent refluxing processes in aqua regia solutions, respectively. The purified material was divided into two batches. The SWCNTs samples were dispersed in 1% SDS solution in ultrasound bath for 2 and 12 hours. Both dispersed SWCNTs samples were functionalized with p-aminobenzoic acid diazonium salt and fractionated via free solution electrophoresis method. Afterwards, the fractionated samples were recovered, purified from surfactant/functionalities by annealing and investigated via UV-Vis-NIR optical absorption spectroscopy (OAS). The efficiency of the fractionation process was estimated through the comparison of the van Hove singularities (vHS) presented in the obtained fractions to the starting SWCNTs.

Keywords

  • SWCNTs
  • diazonium salts
  • fractionation
  • electrophoresis
Open Access

Catalytic synthesis of warfarin acetals by using different heteropolyacid catalysts

Published Online: 05 Oct 2011
Page range: 5 - 11

Abstract

Catalytic synthesis of warfarin acetals by using different heteropolyacid catalysts

In this research, we report on the synthesis of warfarin acetals by using Preyssler's anion, [NaP5W30O110]-14 and heteropolyacids (HPAs) catalysts. This reaction was performed using methanol and ethanol at reflux temperature conditions. Under these conditions we have excellent yields and high selectivity. Preyssler heteropolyacid catalyst were easily recycled recovery and reused without the loss of its catalytic activities. The synthesis of warfarin acetals has been achieved using the catalytic amounts of green, inexpensive and eco-friendly Keggin types heteropolyacids. The products were obtained in high yields.

Keywords

  • Heteropolyacid
  • Preyssler
  • Catalyst
  • Warfarin
  • Cyclic acetals
Open Access

Tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation

Published Online: 05 Oct 2011
Page range: 12 - 17

Abstract

<italic>Tert</italic>-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation

A series of seven substituted tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids has been synthesized, isolated, spectroscopically and structurally elucidated. An influence of the substituents on the spectroscopic characteristics and conformations is discussed using the data of the linear-polarized IR- (IR-LD), UV-spectroscopy and 1H-NMR. Theoretical quantum chemical calculations are carried out, with a view to explaining and supporting the experimental optical properties and the electronic structure. The stereoselective synthesis of the corresponding diastereoisomers is optimized, thus giving good yields (62-72%) and purity of the compounds

Keywords

  • -butyl esters of 2,3-diaryl-3-arylaminopropanoic acids
  • optical properties
  • quantum chemistry
Open Access

Environmental Impact Assessment of Biogas Stations in the Czech Republic

Published Online: 05 Oct 2011
Page range: 18 - 22

Abstract

Environmental Impact Assessment of Biogas Stations in the Czech Republic

The article summarizes the authors' experience with environmental impact assessment in the branch of biogas plants. The introductory part of the paper describes the legislative obligations of the Czech Republic concerning the fulfilment of the European Union's limits as for the utilization of renewable energy resources. The next parts of the paper deal with an impact analysis of biogas plants on the environment. The final part of the paper deals with the experience concerning the implementation of the environmental impact assessment process in the field of biogas plants in the Czech Republic.

Keywords

  • Biogas station
  • environmental impact assessment
  • odour
Open Access

Radioactivity of some building and raw materials used in Croatia

Published Online: 05 Oct 2011
Page range: 23 - 27

Abstract

Radioactivity of some building and raw materials used in Croatia

In the present study, the activity concentrations of 226Ra, 232Th, 40K in some building and raw materials used in Croatia were measured by using a gamma-ray spectrometer with the HPGe detector. The average activity concentrations of the studied different building and raw materials ranged from 11.6 ± 1.7 (concrete) to 251.2 ± 25.7 Bqkg-1 (GBFS), 14.0 ± 2.7 (concrete) to 54.4 ± 8.3 (coal fly ash) and 147.2 ± 19.0 (concrete) to 773.7 ± 82.0 Bqkg-1 (tuff) for 226Ra, 232Th and 40K, respectively. Radium equivalent activity, activity concentration index, absorbed gamma dose rate indoor due to the external exposure and corresponding annual effective dose were determined to estimate the exposure risk arising due to the use of these building and raw materials.

Keywords

  • Radioactivity
  • Building materials
  • Fly ash
  • Gamma-ray spectrometer
  • Annual effective dose
Open Access

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts

Published Online: 05 Oct 2011
Page range: 28 - 36

Abstract

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts

In this work, catalytic activity and stability of Cu/Y5 and Cu/ZSM5 zeolites in phenol oxidation with hydrogen peroxide were examined. The catalyst samples were prepared by the ion exchange method of the protonic form of commercial zeolites. The catalysts were characterized by the powder X-ray diffraction (XRD), AAS, while the adsorption techniques were used to measure the specific surface area.

The thermal programmed desorption of NH3 (NH3-TPD) was used for measuring the total number of acid sites formed on the surface of zeolites.

Catalytic performance of the prepared samples was monitored in terms of phenol, hydrogen peroxide and total organic carbon (TOC) conversion, by-product distribution and a degree of copper leached into the aqueous solution.

It was found that the activity of Cu/Y5 catalyst was generally higher than that of Cu/ZSM5 and that unlike Cu/ZSM5, Cu/Y5 catalyzed phenol oxidation more completely.

Keywords

  • waste water treatment
  • phenol oxidation
  • hydrogen peroxide
  • catalysts
  • Cu/ZSM5
  • Cu/Y5
Open Access

COD reduction studies of paper mill effluent using a batch recirculation electrochemical method

Published Online: 05 Oct 2011
Page range: 37 - 41

Abstract

COD reduction studies of paper mill effluent using a batch recirculation electrochemical method

The conventional method of treating pulp and paper mill effluent involves the biological oxidation by bacterial action of aerobic and anaerobic conditions and aerobic lagooning method, which are less efficiency of removing COD. To overcome the drawbacks of the existing treatment process, in the present work an attempt has been made to study the electro oxidative destruction of the pulp and paper mill effluent using an electrochemical method and the effect of various parameters such as concentration of supporting electrolytes, current densities, flow rates of electrolyte and reservoir volumes of the effluent were conducted. From the experimental results it is observed that the rate of reduction of COD of the effluent increased with an increase in the supporting electrolyte (sodium chloride) concentration, current density where as it decreased with increase in the reservoir volume and the flow rate of electrolyte. The residence time distributions studies have also been conducted to study the behavior of the electrochemical reactor.

Keywords

  • effluent treatment
  • residence time distributions
  • electrochemical reactor
  • Pulp and Paper mill effluent
Open Access

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application

Published Online: 05 Oct 2011
Page range: 42 - 46

Abstract

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application

The results of the study on the reactions of melamine cyanurate with ethylene carbonate were presented. As a result of the reactions, polyetherols containing thermostabile 1,3,5-triazine and perhyroxo-1,3,5-triazine rings in their structure were obtained. Basic physical properties such as density, viscosity, hydroxyl number, weight changes were measured. The polyetherols were applied as a polyol component to receiving of thermoresistant polyurethane foams. Some of the properties of the obtained foams were investigated. The value of the apparent density is between 51 and 71 kg/m3, compressive strength 222-356 kPa and the content of the open pores between 14-33%. Thermal resistance was also studied by means of the TGA method. It was found that oxygen index of the selected compositions is between 20-22%.

Keywords

  • melamine cyanurate
  • ethylene carbonate
  • polyetherols
  • polyurethane foams
Open Access

Modified halloysite as a filler for epoxy resins

Published Online: 05 Oct 2011
Page range: 47 - 52

Abstract

Modified halloysite as a filler for epoxy resins

The modification methods of halloysite and further applications of the modified mineral as a filler for epoxy resins have been presented. The advantage of ultrasound treatment prior to chemical modification with an organic compound in order to obtain a hybrid filler was confirmed. The analysis of the composites obtained with the use of the modified halloysite (3-5 wt.% range) as a filler for epoxy resins indicates an improved interphase interaction and mechanical properties in comparison to the composites based on neat halloysite.

Keywords

  • layered-tubular mineral
  • chemical modification
  • modification with ultrasounds
  • fillers
  • filling of epoxy resins
  • mechanical and thermal properties
Open Access

Present and prospective leather industry waste disposal

Published Online: 05 Oct 2011
Page range: 53 - 55

Abstract

Present and prospective leather industry waste disposal

In this paper general characteristics of the main leather industry waste regarding its amount reduction by thermal treatment have been presented. Both the tannery solid wastes and the sludge contain organic substances. Their energy value is more than 50% higher in comparison to hard coal (nominally 20 MJ/kg as dry material). Up to now, the considerable amounts of energy are not recovered; leather wastes are predominantly on landfill. Implementation of a comprehensive thermal method for tannery solid waste and sludge utilization can permit to solve the waste disposal problem by effective neutralization of all of the waste. Moreover, it should bring economic benefits associated with steam or hot water production and landfill tax avoiding. The study is oriented towards the practical application.

Keywords

  • leather industry
  • tannery waste
  • sewage sludge
  • odor
  • waste treatment
  • thermal neutralization
Open Access

Separation of volatile compounds from fermentation broth by membrane distillation

Published Online: 05 Oct 2011
Page range: 56 - 60

Abstract

Separation of volatile compounds from fermentation broth by membrane distillation

The diluted ethanol solutions and fermentation broth (Saccharomyces cerevisiae) were separated by membrane distillation (MD). Hydrophobic macroporous (pore size 0.2 μm) capillary polypropylene membranes, Accurel PP V8/2 HF and Accurel PP S6/2, were used for these studies. The MD process can be successfully applied to remove the volatile components from the fermentation broth. Besides ethanol, propionic and acetic acids were moved from the broth to the distillate. Therefore, the course of the fermentation carried out in a membrane distillation bioreactor considerably accelerate its rate and increase the efficiency by a selective removal of fermentation products. It was found that the broth subjected to the separation did not affect the hydrophobic properties of the polypropylene membrane assembled in the MD modules.

Keywords

  • fermentation
  • ethanol
  • membrane distillation
Open Access

Studies of properties of polypropylene/halloysite composites

Published Online: 05 Oct 2011
Page range: 61 - 65

Abstract

Studies of properties of polypropylene/halloysite composites

The results of the studies on the synthesis, mechanical and thermal properties of polypropylene composites with various amount of halloysite filler are presented. Halloysite (HNT) belongs to the silica type characterized by a two-layer 1:1 structure. This work was aimed to develop a method for the modification of halloysite in its prime use as a filler for polypropylene by extrusion. The composites contain 1, 3, 5 and 7 wt.% of HNT. The degree of crystallinity of the composites decrease with increasing halloysite content. The results confirm the expectations that composites of interesting physicochemical, mechanical and thermal properties can be obtained. The mechanical properties studied show that the filler modification method used leads to the synthesis of polymer composites of improved thermal and mechanical properties.

Keywords

  • polypropylene
  • composites
  • powder filler
  • halloysite
  • mechanical
  • thermal properties
  • morphology of polymeric materials
  • extrusion
  • injection
Open Access

The investigation of ethanol separation by the membrane distillation process

Published Online: 05 Oct 2011
Page range: 66 - 69

Abstract

The investigation of ethanol separation by the membrane distillation process

Separation of ethanol from solutions with different concentrations in a BIOTRON bioreactor integrated with the direct contact membrane distillation system has been investigated. The experiments were carried out using immersed, capillary polypropylene membranes. The permeability of the membrane at the feed inlet temperatures of 308, 318 and 333K was determined. The permeate and ethanol flux was strongly affected by the vapour pressure which increased with the feed temperature and it was also associated with ethanol concentration in the feed. It was found that the membrane distillation can be successfully applied for the separation of volatile components such as ethanol.

Keywords

  • membrane distillation
  • bioreactor
  • ethanol
  • immersed capillary membranes