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Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-4741
ISSN
1509-8117
Erstveröffentlichung
03 Jul 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 15 (2013): Heft 4 (December 2013)

Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-4741
ISSN
1509-8117
Erstveröffentlichung
03 Jul 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

22 Artikel
access type Uneingeschränkter Zugang

Application of nanofiltration in the process of the separation of model fermentation broths components

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 1 - 4

Zusammenfassung

Abstract

The effectiveness of nanofiltration with the use of ceramic membranes in the process of concentration and separation of fumaric acid or succinic acid from glycerol and citric acid from erythritol was evaluated. It was found that the retention of sodium salts of the acids investigated increased strongly with increasing the pH of the feed solution (depending on the degree of dissociation), while the retention degrees of di- and tricarboxylic acids, erythritol or glycerol were lower than 2%, irrespective of the initial concentration of the solution to be filtered. The results obtained showed that nanofiltration can be considered as one of the purification steps in the process of recovery of salts of organic acids from fermentation broth.

Keywords

  • nanofiltration
  • ceramic membrane
  • fumaric acid
  • succinic acid
  • erythritol
  • glycerol
access type Uneingeschränkter Zugang

Removal of low molecular organic acids from aqueous solutions with reactive extraction

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 5 - 9

Zusammenfassung

Abstract

This paper presents investigation on removal of low molecular organic acids (acetic, lactic, succinic and fumaric) from aqueous solutions with reactive extraction. The results specifically show that the extraction efficiency of acids depends on the type of extractant, diluents of the organic phase and the initial pH of the aqueous phase. It is possible to separate succinic or fumaric from lactic and acetic acids with high selectivity with the use of TOA and Aliquat 336, respectively. Increasing the pH of the aqueous phase results in a reduction of fumaric acid extraction efficiency with solvating extractants. This can be explained by the decreasing share of acidic form, whose extraction is favored by these extractants. Efficient extraction of both fumaric acid and fumarate using Aliquat 336 can be explained by the ionic structure of the quaternary ammonium salt, capable of transporting both forms of the acid.

Keywords

  • reactive extraction
  • trioctylamine
  • tributyl phosphate
  • Cyanex 923
  • fumaric
  • succinic
  • lactic
  • acetic acids
access type Uneingeschränkter Zugang

Improvement of the solubility of rock phosphate by co-composting it with organic components

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 10 - 14

Zusammenfassung

Abstract

One possible way to improve the solubility of phosphate rock is by co-composting it with organic substances. Four variants of composts were made in a biomass composting bioreactor. Ground phosphate rock (GPR) and shredded barley straw, pine sawdust as well as beet pulp pellets were used as compost components. The four composts were different from one another in the type and amount of organic components. The composts were granulated in a pelleting press. Changes in the solubility of phosphorus were assessed via chemical analyses and P-recovery efficiency calculated from the data achieved in a pot experiment. Solubility of ground phosphate rock was increased resulting from co-composting with organic substances, which meant that bioavailability of phosphorus increased. All the tested composts were characterized by a higher ratio of ammonium citrate soluble phosphorus to total phosphorus than non-composted GPR. Co-composting GPR with all the tested organic components yielded better effects than composting it with straw alone. The four composts were characterized by a slow release of P, which justifies our expectation that they will produce residual effects in the years following their application.

Keywords

  • compost
  • straw
  • sawdust
  • beet pulp
  • phosphorite
  • phosphorus availability to plants
access type Uneingeschränkter Zugang

Synthesis and physicochemical characterization of silicafillers modified with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 15 - 23

Zusammenfassung

Abstract

Hybrid nanofillers of silica grafted with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane were obtained by the method based on solvent evaporation with the use of both hydrated or emulsion spherical silica. Octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane was applied as a modifying agent and it was synthesized by employing the hydrosilylation reaction. The effectiveness of modification of the hybrid nanofillers obtained was verified using Fourier transform infrared spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The products obtained were characterized by determination of their physicochemical properties and porous structure, including specific surface area, pore diameter and pore volume. Dispersion degree and particle size of the nanofillers was characterized by NIBS (Non-Invasive Back-scatter) method and laser diffraction technique, while their morphology by transmission electron microscopy.

Keywords

  • octasilsesquioxane
  • silica
  • functionalization
  • hybrid nanofillers
access type Uneingeschränkter Zugang

Extraction protocol for isolation of CNSL by using protic and aprotic solvents from cashew nut and study of their physico-chemical parameter

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 24 - 27

Zusammenfassung

Abstract

Cashew nut shell liquid (CNSL) represents the largest readily available bioresource of alkenyl phenolic compounds. (CNSL) and its derivatives are widely used in polymer-based industries, synthesis of chemicals and intermediates, including bactericides, insecticides and surface active agents. In this work extraction of cashew nut shell liquid from cashew nut shell (CNS) was carried out by using the Soxhlet extraction method in the presence of polar & non-polar solvents. From the extracted CNSL, anacardic acid was selectively isolated and acid free CNSL was treated with liquor ammonia to separate the cardanol and cardol in the stepwise manner. Comparative study for the extracted CNSL and S-was performed. Higher amount of extracted CNSL was obtained from polar solvents. They were all characterized using quantitative analysis by HPLC.

Keywords

  • Cashew nut shell
  • Cashew nut shell liquid
  • Cardanol
  • Soxhlet apparatus
access type Uneingeschränkter Zugang

Hydrogenation of cinnamaldehyde over supported palladium catalysts

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 28 - 32

Zusammenfassung

Abstract

The selective hydrogenation of cinnamaldehyde has been studied using palladium catalysts based on epoxy resin cured with ionic liquids. Characterization of palladium catalysts has involved the following methods: IR spectroscopy, X-ray photoelectron spectroscopy (XPS), AAS spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The investigated catalysts showed high stability and good recycling efficiency what makes them useful for a prolonged use. The factors influencing the selectivity of the supported catalysts were discussed.

Keywords

  • selective hydrogenation
  • supported catalyst
  • epoxy resin
  • ionic liquids
access type Uneingeschränkter Zugang

Leaching of vanadium(V) from the mixture after potassium metavanadate synthesis based on KCl and spent vanadium catalyst

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 33 - 35

Zusammenfassung

Abstract

The results of the leaching of vanadium(V) from the mixture after potassium metavanadate synthesis from KCl and spent vanadium catalyst in the presence of steam were presented. Spent vanadium catalyst was obtained from the waste storage of a chemical plant producing sulfuric acid(VI) by the contact method. The reaction mixture was leached using different solutions: 1 M Na2CO3, 20% CO(NH2)2, 15% NaOH, 15% KOH, 2 M H2SO4. The effect of time and temperature was studied. The results showed that for reaction mixture leached for 4 h at 303 K in the presence of 15% sodium hydroxide solution at a liquid:solid ratio of 10:1, the extent of leaching of vanadium(V) was 95.43%.

Keywords

  • KVO3 synthesis
  • spent vanadium catalyst
  • leaching
  • recovery
  • iron
  • vanadium(V)
access type Uneingeschränkter Zugang

Effect of 1-substituted imidazole derivatives for the curing process of epoxy- -isocyanate composition

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 36 - 41

Zusammenfassung

Abstract

The kinetics of the curing process of isocyanate-epoxy materials hardened in the presence of 1- substituted imidazole derivatives was studied by the Coast-Redfern method. The extent of a conversion parameter of the curing process in two ways was calculated: DSC (peak area integration) and rheology (viscosity changes). The activation energy values were determined for epoxy-isocyanate cured in the presence of 0.5; 1.0 and 2.0 phr 1-substituted imidazole derivatives respectively. Increasing of accelerators amount results in decreasing the activation energy and other kinetic parameters.

Keywords

  • curing process
  • DSC investigation
  • rheometric curves
  • Coats-Redfern method
  • autocatalytic curing process
  • Sesták-Berggren model
access type Uneingeschränkter Zugang

A novel functional MgO ∙ SiO2/polyhedral oligomeric silsesquioxane hybrids as an active filler of polypropylene

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 42 - 48

Zusammenfassung

Abstract

New organic/inorganic hybrid fillers were obtained by mechanical modification of magnesium silicate with selected polyhedral oligomeric silsesquioxane and characterized afterwards. MgO ∙ SiO2 was precipitated in a water system. The effect of chemical modification of magnesium silicate surface on their physicochemical properties was determined. Functionalization was carried out with the use of different amount of (1-(3-hydroxypropyl)dimethylsiloxy- 3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13, 9.15, 15.17, 13]octasiloxane). The polypropylene composites of 0.5, 1.0 and 1.5 wt.% modified by 10 weight parts by the mass of the filler were also produced. For the obtained polypropylene composites measurements of the tensile strength, Young’s modulus and elongation at break were performed

Keywords

  • Hybrids fillers
  • Magnesium silicate
  • Polyhedral oligomeric silsesquioxane
  • Polypropylene
  • Polymer composites
  • Mechanical properties
access type Uneingeschränkter Zugang

Investigation of the thermal protection ablative properties of thermosetting composites with powder fillers: the corundum Al2O3 and the Carbon Powder C

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 49 - 53

Zusammenfassung

Abstract

Phenol formaldehyde resins were filled with mixtures of corundum Al2O3 and carbon C powders to produce thermoprotective composites. The composites were treated with hot combustion gases to determinate the temperature profiles across rectangular samples of dimensions 10x25x35 mm. The carbonization of the thermosetting matrix was observed. It was qualified the qualitative and the quantitative effect of components on the ablation surface temperature, the back side temperature of specimen and the mass waste under intensive heat fl ow after 120 s of treatment with hot combustion gases. The composites with higher matrix content (more liquid resin and less adhesive resin) and with predominance of corundum Al2O3 over carbon powder C showed the best insulating properties.

Keywords

  • ablative shields and coats
  • thermosetting polymer composites
  • high-melting fillers
  • thermoprotective materials
access type Uneingeschränkter Zugang

Optimization of rapeseed oil fatty acid esterification with methanol in the presence of sulfuric acid

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 54 - 59

Zusammenfassung

Abstract

The interest in biodiesel production from low cost feedstocks is still increasing. Such feedstocks usually contain large amounts of free fatty acids, which make the currently employed base catalysts inefficient, thereby promoting the use of acid catalysts. Due to the high activity and low cost, sulfuric acid could become the most widely used acid catalyst for biodiesel production. Research undertaken so far using sulfuric acid for esterifi cation of fatty acids has shown that the products obtained fail to meet the requirements of the standard EN 14214. This paper describes a systematic study of rapeseed oil fatty acids esterification in order to obtain a product complying with the standard EN 14214. The influence of sulfuric acid concentrations (0.1-3.0%), methanol molar ratios (1:1-20:1) and reaction time (0-360 min) was evaluated. Finally, a two-stage esterification process was developed, where in optimal conditions esterification yield of 97.8% and ester content of 99.6% were achieved.

Keywords

  • biodiesel
  • free fatty acids
  • sulfuric acid
  • methanol
  • esterification
access type Uneingeschränkter Zugang

Inhibitive tendency of zinc gluconate for aluminium alloy in sulphuric acid solution

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 60 - 64

Zusammenfassung

Abstract

The corrosion inhibition of aluminium alloy in 0.5M H2SO4 solution in the presence of zinc gluconate at 301 K was investigated using weight loss and an electrochemical method. Surface analysis of the aluminium alloy sample was reviewed by a high resolution scanning electron microscope equipped with energy dispersive spectroscopy (HRSEM/ EDS). The readings were taken after 48 h for 28 days while the concentration of the inhibitor was varied from 0.5 to 2.0% g/v with an interval of 0.5. The result of the investigation shows that zinc gluconate has a good corrosion inhibition effect for aluminium alloy in 0.5 molar sulphuric acid solution and its efficiency attains more than 67% at 1.5% g/v concentration of zinc gluconate at 301 K. The potentiodynamic polarization data showed that zinc gluconate acts as a mixed type corrosion inhibitor. The adsorption of zinc gluconate on aluminium alloy has been found to obey Freundlich adsorption isotherm at all the concentration of zinc gluconate studied. The results obtained from different methods are in good agreement.

Keywords

  • aluminium
  • zinc gluconate
  • inhibition
  • weight loss
  • potentiodynamic polarization
  • SEM/EDS
access type Uneingeschränkter Zugang

New thermoplastic polyurethane elastomers based on sulfur-containing chain extenders

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 65 - 70

Zusammenfassung

Abstract

New thermoplastic polyurethane elastomers (TPUs) were synthesized by a one-step melt polyaddition from poly(oxytetramethylene) diol of M¯n = 2000 g/mol as the soft segment, 1,1’-methanediylbis(4-isocyanatocyclohexane) (HMDI, Desmodur W®), and 2,2’-[methanediylbis(benzene-4,1-diylmethanediylsulfanediyl)]diethanol (diol E) or 6,6’-[methanediylbis(benzene-4,1-diylmethanediylsulfanediyl)]dihexane-1-ol (diol H) as unconventional chain extenders. The effects of the kind and amount of the polymer diol and chain extender used on the structure and properties of the polymers were studied. The polymers were examined by Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, Shore hardness and tensile testing. Both the adhesive and optical properties were determinated for a selected polymer. The obtained TPUs were amorphous, colorless, high-molar-mass materials. It was observed that the polymers with the diol E showed higher hardness and tensile strengths but smaller elongations at break than diol H-based ones. All of the polymers exhibited a relatively good thermal stability. Their temperatures of 5% mass loss were in the range 312-338°C.

Keywords

  • sulfur-containing thermoplastic elastomers
  • amorphous polymers
  • polyether soft segments
  • melt polyaddition
  • thermal and mechanical properties
  • adhesion to copper
  • optical properties
access type Uneingeschränkter Zugang

Influence of heterogeneous nucleation on thermodynamic properties of isotactic polypropylene

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 71 - 74

Zusammenfassung

Abstract

In this paper we have investigated the effect of 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol sorbitol used in varying amounts (0.01 - 1 wt %) on isotactic polypropylene (iPP) matrix. We have used dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) to study glass transition temperatures and crystallinity as a function of the nucleating agent concentration. Isotactic polypropylene samples showed a strong dependency on amount of α nucleating agent used. An increasing content of sorbitol based nucleating agent led to an increase of crystallization temperature upon cooling from the melt at constant rate and a decrease of the glass transition temperatures.

Keywords

  • isotactic polypropylene
  • PP
  • heterogeneous
  • nucleation
  • modifi cation
  • sorbitol
  • DMTA
  • DSC
access type Uneingeschränkter Zugang

The influence of process parameters on combustion of plastic waste in the fluidized bed reactor

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 75 - 79

Zusammenfassung

Abstract

The paper presents the results of a research on the effects of process parameters on the combustion of waste plastics. The experiments were carried out in a laboratory fluidized bed reactor. The temperature and the conditions of the process were changed during the experiments. The plastics were combusted continuously (autothermally), periodically with extra fuel (co-firing) and alone in a hot fluidized bed. During the combustion process of materials containing nitrogen (PA, ABS), while the bed temperature decrease, changes of emissions of nitrogen oxides, in particular an increase in the concentration of N2O, up to 250 ppm at ~730°C, were observed. During ABS combustion, emission of HCN was registered, at a maximum of 400 ppm. The presence of the supporting fuel (LPG) resulted in the stabilization and acceleration of the plastic samples degradation process. The rate of thermal decomposition of waste materials depended on its elemental composition and also the physicochemical properties.

Keywords

  • plastics
  • fluidization
  • combustion
  • thermal decomposition
  • polymers
  • fluidized bed reactor
  • municipal waste
  • waste utilization
  • fluidized bed
access type Uneingeschränkter Zugang

Investigations on the synthesis and properties of biodegradable poly(ester-carbonate-urea-urethane)s

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 80 - 88

Zusammenfassung

Abstract

A new method of the synthesis of oligo(tetramethylene succinate-co-carbonate) diols using dimethyl succinate, 1,4-butanediol and tetramethylene bis(methyl carbonate) was elaborated. The resultant oligomerols (Mn = 2600- 3700) were characterized by FTIR, 1H NMR, GPC and DSC analysis. Depending on the content of carbonate units in the polymer molecules, the melting point of the crystalline phase changes significantly. The synthesis of poly(ester-carbonate-urea-urethane)s was carried out with two aliphatic diisocyanates - cyclic IPDI or linear HDI. The resultant products exhibited very good mechanical properties - tensile strength up to 60 MPa and elongation at break about 500%. Preliminary studies confirmed that the presence of ester units in the soft segments as well as lack of crystalline phase significantly enhances the biodegradability of the PUR in comparison to that of polyurethanes based on carbonate oligomers.

Keywords

  • polyurethane
  • oligo(ester-carbonate) diol
  • biodegradation
access type Uneingeschränkter Zugang

Influence of the kind and concentration of ethoxylated alcohols on the transport of citric acid through polymer inclusion membranes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 89 - 94

Zusammenfassung

Abstract

Research into the influence of ethoxylated alcohols on the citric acid transport through polymer inclusion membranes (PIMs) has been carried out. This process may be used in the future as one of the methods of citric acid isolation. Ethoxylated alcohols, which were GENAPOL® X020, X060 and X150, served as both: plasticizer and carrier. The results showed that the maximum values of citric acid fl ux [mol/(m2.s)] were equal to: 1.02.10-4 (X020), 1.57.10-4 (X060) and 1.77.10-4 (X150). The obtained results allow proceeding further study on using the polymer inclusion membranes, as an alternative to traditional methods of citric acid separation, which are precipitation and extraction.

Keywords

  • citric acid
  • polymer inclusion membranes
  • ethoxylated alcohols
access type Uneingeschränkter Zugang

Effect of boron on ZSM-5 catalyst for methanol to propylene conversion

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 95 - 101

Zusammenfassung

Abstract

B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.

Keywords

  • methanol to propylene
  • ZSM-5
  • boron modifi cation
  • propylene
access type Uneingeschränkter Zugang

Utilization of spent brewer’s yeast for supplementation of distillery corn mashes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 102 - 106

Zusammenfassung

Abstract

The aim of the study was to use spent brewer’s yeast biomass (SBY) as a nutrient adjunct of distillery type corn mashes to improve the process of ethanol fermentation by yeast Saccharomyces cerevisiae. There were prepared corn mashes with raw material loading at 20% ww. with SBY addition at solids loadings of 0 (control); 0.1; 0.5; 0.7; 1.0; 3.0 and 5.0% ww. The obtained mashes were inoculated with yeast and subjected to batch fermentation for 72 h. It was observed that supplementation of corn mashes with SBY improved the process of fermentation. The consumption of sugars and production of ethanol by yeast in supplemented mashes was accelerated and the overall ethanol yield was improved by 6.5 to 11% depending on the amount of added SBY. It was also observed that the fermentation could be shortened by 24 h in mashes enriched with SBY.

Keywords

  • ethanol fermentation
  • corn mash
  • spent brewer’s yeast
  • Saccharomyces cerevisiae
access type Uneingeschränkter Zugang

The dependance of an activity of vanadium catalysts on a carrier regeneration method and an active phase composition

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 107 - 110

Zusammenfassung

Abstract

The results of the research studies concerning the reaction rate of SO2 oxidation on the vanadium catalysts have been described. A carrier of the active phase - silica has been regenerated from spent vanadium mass by leaching with H2SO4 solution. The dependence of the oxidation reaction rate on the method of treating a catalyst carrier as well as the composition of an active phase of the new catalyst systems has been also presented.

Keywords

  • carrier properties
  • composition of active phase
  • SO2 oxidation
  • vanadium catalysts
access type Uneingeschränkter Zugang

Studies on the deactivation of Ti-MCM-41 catalyst in the process of allyl alcohol epoxidation

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 111 - 115

Zusammenfassung

Abstract

The synthesis of Ti-MCM-41 catalyst was performed. The obtained catalyst was characterized by the following instrumental methods: UV-vis, IR spectroscopy, XRD, and X-ray microanalysis. The activity of the obtained catalyst was tested in the process of allyl alcohol epoxidation with 30 wt.% hydrogen peroxide in methanol as a solvent and under atmospheric pressure. In the next stage, recovery of Ti-MCM-41 catalyst from the post-reaction mixture and its regeneration by washing with appropriate solvents and drying were conducted. In the case of total loss of the activity of the catalyst, calcination of the catalyst was also carried out. The loss of titanium from the structure of Ti-MCM-41 catalyst and a partial collapsing of the structure of this catalyst can be the main reason of the decrease the activity of the catalyst what was manly visible in the decrease of the values of two functions of this process: the allyl alcohol conversion and conversion of hydrogen peroxide to organic compounds.

Keywords

  • titanium silicate Ti-MCM-41 catalyst
  • deactivation of Ti-MCM-41catalyst
  • regeneration of Ti-MCM-41catalyst
access type Uneingeschränkter Zugang

Remediation of heavy metals from soil using quartz sand functionalized with organic amino silanes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 116 - 120

Zusammenfassung

Abstract

The results of the research studies concerning the binding of heavy metals (HMs) by quartz sand functionalized with amino silanes have been described. The studies have been carried out on soils sampled from the areas affected by emissions from Copper Smelter and Refinery. The research aims to increase the food safety in the areas of industrial impact. The presence of polyamine chain in the hybrid materials obtained enables a binding of heavy metals (nickel, copper, cobalt). The best results are observed for the hybrid material having four amine groups (four coordination centers) per molecule. For this material the highest content after two extraction cycles (pH 7.0 and 5.0) is observed for copper (98.2%), but for other ions (nickel, cobalt) it is at least 85% of the initial amount of components available for plants.

Keywords

  • quartz sand
  • heavy metals
  • soil stabilization
22 Artikel
access type Uneingeschränkter Zugang

Application of nanofiltration in the process of the separation of model fermentation broths components

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 1 - 4

Zusammenfassung

Abstract

The effectiveness of nanofiltration with the use of ceramic membranes in the process of concentration and separation of fumaric acid or succinic acid from glycerol and citric acid from erythritol was evaluated. It was found that the retention of sodium salts of the acids investigated increased strongly with increasing the pH of the feed solution (depending on the degree of dissociation), while the retention degrees of di- and tricarboxylic acids, erythritol or glycerol were lower than 2%, irrespective of the initial concentration of the solution to be filtered. The results obtained showed that nanofiltration can be considered as one of the purification steps in the process of recovery of salts of organic acids from fermentation broth.

Keywords

  • nanofiltration
  • ceramic membrane
  • fumaric acid
  • succinic acid
  • erythritol
  • glycerol
access type Uneingeschränkter Zugang

Removal of low molecular organic acids from aqueous solutions with reactive extraction

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 5 - 9

Zusammenfassung

Abstract

This paper presents investigation on removal of low molecular organic acids (acetic, lactic, succinic and fumaric) from aqueous solutions with reactive extraction. The results specifically show that the extraction efficiency of acids depends on the type of extractant, diluents of the organic phase and the initial pH of the aqueous phase. It is possible to separate succinic or fumaric from lactic and acetic acids with high selectivity with the use of TOA and Aliquat 336, respectively. Increasing the pH of the aqueous phase results in a reduction of fumaric acid extraction efficiency with solvating extractants. This can be explained by the decreasing share of acidic form, whose extraction is favored by these extractants. Efficient extraction of both fumaric acid and fumarate using Aliquat 336 can be explained by the ionic structure of the quaternary ammonium salt, capable of transporting both forms of the acid.

Keywords

  • reactive extraction
  • trioctylamine
  • tributyl phosphate
  • Cyanex 923
  • fumaric
  • succinic
  • lactic
  • acetic acids
access type Uneingeschränkter Zugang

Improvement of the solubility of rock phosphate by co-composting it with organic components

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 10 - 14

Zusammenfassung

Abstract

One possible way to improve the solubility of phosphate rock is by co-composting it with organic substances. Four variants of composts were made in a biomass composting bioreactor. Ground phosphate rock (GPR) and shredded barley straw, pine sawdust as well as beet pulp pellets were used as compost components. The four composts were different from one another in the type and amount of organic components. The composts were granulated in a pelleting press. Changes in the solubility of phosphorus were assessed via chemical analyses and P-recovery efficiency calculated from the data achieved in a pot experiment. Solubility of ground phosphate rock was increased resulting from co-composting with organic substances, which meant that bioavailability of phosphorus increased. All the tested composts were characterized by a higher ratio of ammonium citrate soluble phosphorus to total phosphorus than non-composted GPR. Co-composting GPR with all the tested organic components yielded better effects than composting it with straw alone. The four composts were characterized by a slow release of P, which justifies our expectation that they will produce residual effects in the years following their application.

Keywords

  • compost
  • straw
  • sawdust
  • beet pulp
  • phosphorite
  • phosphorus availability to plants
access type Uneingeschränkter Zugang

Synthesis and physicochemical characterization of silicafillers modified with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 15 - 23

Zusammenfassung

Abstract

Hybrid nanofillers of silica grafted with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane were obtained by the method based on solvent evaporation with the use of both hydrated or emulsion spherical silica. Octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane was applied as a modifying agent and it was synthesized by employing the hydrosilylation reaction. The effectiveness of modification of the hybrid nanofillers obtained was verified using Fourier transform infrared spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The products obtained were characterized by determination of their physicochemical properties and porous structure, including specific surface area, pore diameter and pore volume. Dispersion degree and particle size of the nanofillers was characterized by NIBS (Non-Invasive Back-scatter) method and laser diffraction technique, while their morphology by transmission electron microscopy.

Keywords

  • octasilsesquioxane
  • silica
  • functionalization
  • hybrid nanofillers
access type Uneingeschränkter Zugang

Extraction protocol for isolation of CNSL by using protic and aprotic solvents from cashew nut and study of their physico-chemical parameter

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 24 - 27

Zusammenfassung

Abstract

Cashew nut shell liquid (CNSL) represents the largest readily available bioresource of alkenyl phenolic compounds. (CNSL) and its derivatives are widely used in polymer-based industries, synthesis of chemicals and intermediates, including bactericides, insecticides and surface active agents. In this work extraction of cashew nut shell liquid from cashew nut shell (CNS) was carried out by using the Soxhlet extraction method in the presence of polar & non-polar solvents. From the extracted CNSL, anacardic acid was selectively isolated and acid free CNSL was treated with liquor ammonia to separate the cardanol and cardol in the stepwise manner. Comparative study for the extracted CNSL and S-was performed. Higher amount of extracted CNSL was obtained from polar solvents. They were all characterized using quantitative analysis by HPLC.

Keywords

  • Cashew nut shell
  • Cashew nut shell liquid
  • Cardanol
  • Soxhlet apparatus
access type Uneingeschränkter Zugang

Hydrogenation of cinnamaldehyde over supported palladium catalysts

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 28 - 32

Zusammenfassung

Abstract

The selective hydrogenation of cinnamaldehyde has been studied using palladium catalysts based on epoxy resin cured with ionic liquids. Characterization of palladium catalysts has involved the following methods: IR spectroscopy, X-ray photoelectron spectroscopy (XPS), AAS spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The investigated catalysts showed high stability and good recycling efficiency what makes them useful for a prolonged use. The factors influencing the selectivity of the supported catalysts were discussed.

Keywords

  • selective hydrogenation
  • supported catalyst
  • epoxy resin
  • ionic liquids
access type Uneingeschränkter Zugang

Leaching of vanadium(V) from the mixture after potassium metavanadate synthesis based on KCl and spent vanadium catalyst

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 33 - 35

Zusammenfassung

Abstract

The results of the leaching of vanadium(V) from the mixture after potassium metavanadate synthesis from KCl and spent vanadium catalyst in the presence of steam were presented. Spent vanadium catalyst was obtained from the waste storage of a chemical plant producing sulfuric acid(VI) by the contact method. The reaction mixture was leached using different solutions: 1 M Na2CO3, 20% CO(NH2)2, 15% NaOH, 15% KOH, 2 M H2SO4. The effect of time and temperature was studied. The results showed that for reaction mixture leached for 4 h at 303 K in the presence of 15% sodium hydroxide solution at a liquid:solid ratio of 10:1, the extent of leaching of vanadium(V) was 95.43%.

Keywords

  • KVO3 synthesis
  • spent vanadium catalyst
  • leaching
  • recovery
  • iron
  • vanadium(V)
access type Uneingeschränkter Zugang

Effect of 1-substituted imidazole derivatives for the curing process of epoxy- -isocyanate composition

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 36 - 41

Zusammenfassung

Abstract

The kinetics of the curing process of isocyanate-epoxy materials hardened in the presence of 1- substituted imidazole derivatives was studied by the Coast-Redfern method. The extent of a conversion parameter of the curing process in two ways was calculated: DSC (peak area integration) and rheology (viscosity changes). The activation energy values were determined for epoxy-isocyanate cured in the presence of 0.5; 1.0 and 2.0 phr 1-substituted imidazole derivatives respectively. Increasing of accelerators amount results in decreasing the activation energy and other kinetic parameters.

Keywords

  • curing process
  • DSC investigation
  • rheometric curves
  • Coats-Redfern method
  • autocatalytic curing process
  • Sesták-Berggren model
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A novel functional MgO ∙ SiO2/polyhedral oligomeric silsesquioxane hybrids as an active filler of polypropylene

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 42 - 48

Zusammenfassung

Abstract

New organic/inorganic hybrid fillers were obtained by mechanical modification of magnesium silicate with selected polyhedral oligomeric silsesquioxane and characterized afterwards. MgO ∙ SiO2 was precipitated in a water system. The effect of chemical modification of magnesium silicate surface on their physicochemical properties was determined. Functionalization was carried out with the use of different amount of (1-(3-hydroxypropyl)dimethylsiloxy- 3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13, 9.15, 15.17, 13]octasiloxane). The polypropylene composites of 0.5, 1.0 and 1.5 wt.% modified by 10 weight parts by the mass of the filler were also produced. For the obtained polypropylene composites measurements of the tensile strength, Young’s modulus and elongation at break were performed

Keywords

  • Hybrids fillers
  • Magnesium silicate
  • Polyhedral oligomeric silsesquioxane
  • Polypropylene
  • Polymer composites
  • Mechanical properties
access type Uneingeschränkter Zugang

Investigation of the thermal protection ablative properties of thermosetting composites with powder fillers: the corundum Al2O3 and the Carbon Powder C

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 49 - 53

Zusammenfassung

Abstract

Phenol formaldehyde resins were filled with mixtures of corundum Al2O3 and carbon C powders to produce thermoprotective composites. The composites were treated with hot combustion gases to determinate the temperature profiles across rectangular samples of dimensions 10x25x35 mm. The carbonization of the thermosetting matrix was observed. It was qualified the qualitative and the quantitative effect of components on the ablation surface temperature, the back side temperature of specimen and the mass waste under intensive heat fl ow after 120 s of treatment with hot combustion gases. The composites with higher matrix content (more liquid resin and less adhesive resin) and with predominance of corundum Al2O3 over carbon powder C showed the best insulating properties.

Keywords

  • ablative shields and coats
  • thermosetting polymer composites
  • high-melting fillers
  • thermoprotective materials
access type Uneingeschränkter Zugang

Optimization of rapeseed oil fatty acid esterification with methanol in the presence of sulfuric acid

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 54 - 59

Zusammenfassung

Abstract

The interest in biodiesel production from low cost feedstocks is still increasing. Such feedstocks usually contain large amounts of free fatty acids, which make the currently employed base catalysts inefficient, thereby promoting the use of acid catalysts. Due to the high activity and low cost, sulfuric acid could become the most widely used acid catalyst for biodiesel production. Research undertaken so far using sulfuric acid for esterifi cation of fatty acids has shown that the products obtained fail to meet the requirements of the standard EN 14214. This paper describes a systematic study of rapeseed oil fatty acids esterification in order to obtain a product complying with the standard EN 14214. The influence of sulfuric acid concentrations (0.1-3.0%), methanol molar ratios (1:1-20:1) and reaction time (0-360 min) was evaluated. Finally, a two-stage esterification process was developed, where in optimal conditions esterification yield of 97.8% and ester content of 99.6% were achieved.

Keywords

  • biodiesel
  • free fatty acids
  • sulfuric acid
  • methanol
  • esterification
access type Uneingeschränkter Zugang

Inhibitive tendency of zinc gluconate for aluminium alloy in sulphuric acid solution

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 60 - 64

Zusammenfassung

Abstract

The corrosion inhibition of aluminium alloy in 0.5M H2SO4 solution in the presence of zinc gluconate at 301 K was investigated using weight loss and an electrochemical method. Surface analysis of the aluminium alloy sample was reviewed by a high resolution scanning electron microscope equipped with energy dispersive spectroscopy (HRSEM/ EDS). The readings were taken after 48 h for 28 days while the concentration of the inhibitor was varied from 0.5 to 2.0% g/v with an interval of 0.5. The result of the investigation shows that zinc gluconate has a good corrosion inhibition effect for aluminium alloy in 0.5 molar sulphuric acid solution and its efficiency attains more than 67% at 1.5% g/v concentration of zinc gluconate at 301 K. The potentiodynamic polarization data showed that zinc gluconate acts as a mixed type corrosion inhibitor. The adsorption of zinc gluconate on aluminium alloy has been found to obey Freundlich adsorption isotherm at all the concentration of zinc gluconate studied. The results obtained from different methods are in good agreement.

Keywords

  • aluminium
  • zinc gluconate
  • inhibition
  • weight loss
  • potentiodynamic polarization
  • SEM/EDS
access type Uneingeschränkter Zugang

New thermoplastic polyurethane elastomers based on sulfur-containing chain extenders

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 65 - 70

Zusammenfassung

Abstract

New thermoplastic polyurethane elastomers (TPUs) were synthesized by a one-step melt polyaddition from poly(oxytetramethylene) diol of M¯n = 2000 g/mol as the soft segment, 1,1’-methanediylbis(4-isocyanatocyclohexane) (HMDI, Desmodur W®), and 2,2’-[methanediylbis(benzene-4,1-diylmethanediylsulfanediyl)]diethanol (diol E) or 6,6’-[methanediylbis(benzene-4,1-diylmethanediylsulfanediyl)]dihexane-1-ol (diol H) as unconventional chain extenders. The effects of the kind and amount of the polymer diol and chain extender used on the structure and properties of the polymers were studied. The polymers were examined by Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, Shore hardness and tensile testing. Both the adhesive and optical properties were determinated for a selected polymer. The obtained TPUs were amorphous, colorless, high-molar-mass materials. It was observed that the polymers with the diol E showed higher hardness and tensile strengths but smaller elongations at break than diol H-based ones. All of the polymers exhibited a relatively good thermal stability. Their temperatures of 5% mass loss were in the range 312-338°C.

Keywords

  • sulfur-containing thermoplastic elastomers
  • amorphous polymers
  • polyether soft segments
  • melt polyaddition
  • thermal and mechanical properties
  • adhesion to copper
  • optical properties
access type Uneingeschränkter Zugang

Influence of heterogeneous nucleation on thermodynamic properties of isotactic polypropylene

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 71 - 74

Zusammenfassung

Abstract

In this paper we have investigated the effect of 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol sorbitol used in varying amounts (0.01 - 1 wt %) on isotactic polypropylene (iPP) matrix. We have used dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) to study glass transition temperatures and crystallinity as a function of the nucleating agent concentration. Isotactic polypropylene samples showed a strong dependency on amount of α nucleating agent used. An increasing content of sorbitol based nucleating agent led to an increase of crystallization temperature upon cooling from the melt at constant rate and a decrease of the glass transition temperatures.

Keywords

  • isotactic polypropylene
  • PP
  • heterogeneous
  • nucleation
  • modifi cation
  • sorbitol
  • DMTA
  • DSC
access type Uneingeschränkter Zugang

The influence of process parameters on combustion of plastic waste in the fluidized bed reactor

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 75 - 79

Zusammenfassung

Abstract

The paper presents the results of a research on the effects of process parameters on the combustion of waste plastics. The experiments were carried out in a laboratory fluidized bed reactor. The temperature and the conditions of the process were changed during the experiments. The plastics were combusted continuously (autothermally), periodically with extra fuel (co-firing) and alone in a hot fluidized bed. During the combustion process of materials containing nitrogen (PA, ABS), while the bed temperature decrease, changes of emissions of nitrogen oxides, in particular an increase in the concentration of N2O, up to 250 ppm at ~730°C, were observed. During ABS combustion, emission of HCN was registered, at a maximum of 400 ppm. The presence of the supporting fuel (LPG) resulted in the stabilization and acceleration of the plastic samples degradation process. The rate of thermal decomposition of waste materials depended on its elemental composition and also the physicochemical properties.

Keywords

  • plastics
  • fluidization
  • combustion
  • thermal decomposition
  • polymers
  • fluidized bed reactor
  • municipal waste
  • waste utilization
  • fluidized bed
access type Uneingeschränkter Zugang

Investigations on the synthesis and properties of biodegradable poly(ester-carbonate-urea-urethane)s

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 80 - 88

Zusammenfassung

Abstract

A new method of the synthesis of oligo(tetramethylene succinate-co-carbonate) diols using dimethyl succinate, 1,4-butanediol and tetramethylene bis(methyl carbonate) was elaborated. The resultant oligomerols (Mn = 2600- 3700) were characterized by FTIR, 1H NMR, GPC and DSC analysis. Depending on the content of carbonate units in the polymer molecules, the melting point of the crystalline phase changes significantly. The synthesis of poly(ester-carbonate-urea-urethane)s was carried out with two aliphatic diisocyanates - cyclic IPDI or linear HDI. The resultant products exhibited very good mechanical properties - tensile strength up to 60 MPa and elongation at break about 500%. Preliminary studies confirmed that the presence of ester units in the soft segments as well as lack of crystalline phase significantly enhances the biodegradability of the PUR in comparison to that of polyurethanes based on carbonate oligomers.

Keywords

  • polyurethane
  • oligo(ester-carbonate) diol
  • biodegradation
access type Uneingeschränkter Zugang

Influence of the kind and concentration of ethoxylated alcohols on the transport of citric acid through polymer inclusion membranes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 89 - 94

Zusammenfassung

Abstract

Research into the influence of ethoxylated alcohols on the citric acid transport through polymer inclusion membranes (PIMs) has been carried out. This process may be used in the future as one of the methods of citric acid isolation. Ethoxylated alcohols, which were GENAPOL® X020, X060 and X150, served as both: plasticizer and carrier. The results showed that the maximum values of citric acid fl ux [mol/(m2.s)] were equal to: 1.02.10-4 (X020), 1.57.10-4 (X060) and 1.77.10-4 (X150). The obtained results allow proceeding further study on using the polymer inclusion membranes, as an alternative to traditional methods of citric acid separation, which are precipitation and extraction.

Keywords

  • citric acid
  • polymer inclusion membranes
  • ethoxylated alcohols
access type Uneingeschränkter Zugang

Effect of boron on ZSM-5 catalyst for methanol to propylene conversion

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 95 - 101

Zusammenfassung

Abstract

B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.

Keywords

  • methanol to propylene
  • ZSM-5
  • boron modifi cation
  • propylene
access type Uneingeschränkter Zugang

Utilization of spent brewer’s yeast for supplementation of distillery corn mashes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 102 - 106

Zusammenfassung

Abstract

The aim of the study was to use spent brewer’s yeast biomass (SBY) as a nutrient adjunct of distillery type corn mashes to improve the process of ethanol fermentation by yeast Saccharomyces cerevisiae. There were prepared corn mashes with raw material loading at 20% ww. with SBY addition at solids loadings of 0 (control); 0.1; 0.5; 0.7; 1.0; 3.0 and 5.0% ww. The obtained mashes were inoculated with yeast and subjected to batch fermentation for 72 h. It was observed that supplementation of corn mashes with SBY improved the process of fermentation. The consumption of sugars and production of ethanol by yeast in supplemented mashes was accelerated and the overall ethanol yield was improved by 6.5 to 11% depending on the amount of added SBY. It was also observed that the fermentation could be shortened by 24 h in mashes enriched with SBY.

Keywords

  • ethanol fermentation
  • corn mash
  • spent brewer’s yeast
  • Saccharomyces cerevisiae
access type Uneingeschränkter Zugang

The dependance of an activity of vanadium catalysts on a carrier regeneration method and an active phase composition

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 107 - 110

Zusammenfassung

Abstract

The results of the research studies concerning the reaction rate of SO2 oxidation on the vanadium catalysts have been described. A carrier of the active phase - silica has been regenerated from spent vanadium mass by leaching with H2SO4 solution. The dependence of the oxidation reaction rate on the method of treating a catalyst carrier as well as the composition of an active phase of the new catalyst systems has been also presented.

Keywords

  • carrier properties
  • composition of active phase
  • SO2 oxidation
  • vanadium catalysts
access type Uneingeschränkter Zugang

Studies on the deactivation of Ti-MCM-41 catalyst in the process of allyl alcohol epoxidation

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 111 - 115

Zusammenfassung

Abstract

The synthesis of Ti-MCM-41 catalyst was performed. The obtained catalyst was characterized by the following instrumental methods: UV-vis, IR spectroscopy, XRD, and X-ray microanalysis. The activity of the obtained catalyst was tested in the process of allyl alcohol epoxidation with 30 wt.% hydrogen peroxide in methanol as a solvent and under atmospheric pressure. In the next stage, recovery of Ti-MCM-41 catalyst from the post-reaction mixture and its regeneration by washing with appropriate solvents and drying were conducted. In the case of total loss of the activity of the catalyst, calcination of the catalyst was also carried out. The loss of titanium from the structure of Ti-MCM-41 catalyst and a partial collapsing of the structure of this catalyst can be the main reason of the decrease the activity of the catalyst what was manly visible in the decrease of the values of two functions of this process: the allyl alcohol conversion and conversion of hydrogen peroxide to organic compounds.

Keywords

  • titanium silicate Ti-MCM-41 catalyst
  • deactivation of Ti-MCM-41catalyst
  • regeneration of Ti-MCM-41catalyst
access type Uneingeschränkter Zugang

Remediation of heavy metals from soil using quartz sand functionalized with organic amino silanes

Online veröffentlicht: 31 Dec 2013
Seitenbereich: 116 - 120

Zusammenfassung

Abstract

The results of the research studies concerning the binding of heavy metals (HMs) by quartz sand functionalized with amino silanes have been described. The studies have been carried out on soils sampled from the areas affected by emissions from Copper Smelter and Refinery. The research aims to increase the food safety in the areas of industrial impact. The presence of polyamine chain in the hybrid materials obtained enables a binding of heavy metals (nickel, copper, cobalt). The best results are observed for the hybrid material having four amine groups (four coordination centers) per molecule. For this material the highest content after two extraction cycles (pH 7.0 and 5.0) is observed for copper (98.2%), but for other ions (nickel, cobalt) it is at least 85% of the initial amount of components available for plants.

Keywords

  • quartz sand
  • heavy metals
  • soil stabilization

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