Indian Journal of Chemical Technology
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VOLUME 13

NUMBER 5

SEPTEMBER 2006

CODEN: ICHTEU

 

ISSN:0971-457X

 

 

CONTENTS

 

Papers

 

 

Modelling of the displacement washing of pulp fibre bed

433

        IPC Code: D21C9/02

 

        Shelly Arora, S S Dhaliwal & V K Kukreja

 

 

Simultaneous heat and mass transfer studies in drying ammonium chloride in a batch-fluidized bed dryer

 

440

        IPC Code: C09K5/00, B01J8/00

 

        R Kumaresan & T Viruthagiri

 

 

Hydrophobic flocculation characteristics of calcite and effects of some inorganic dispersants

448

        IPC Code: C02F1/52

 

        H Ucbeyiay & A Ozkan

 

 

An easy spectrophotometric determination of selenium using azure B as a chromogenic reagent

455

        IPC Code: C01B19/00, G01J3/00

 

        Mendalin Mathew & Badiadka Narayana

 

 

Reversible inhibition of polyphenol oxidase from apple using L-cysteine

459

        IPC Code: C12N9/00

 

        R N Gacche, A M Shete, N A Dhole & V S Ghole

 

 

Application of chitosan and alginate in treating waste water containing heavy metal ions

464

        IPC Code: C02F1/00, C02F1/62

 

        Yimin Qin, Bingbing Shi & Jingjie Liu

 

 

Diacetylmonoxime-(p-anisyl)-thiosemicarbazone as a new chromogenicreagent for determination of thallium

 

470

        IPC Code: C22B61/00

 

        Anitha Varghese & A M A Khadar

 

 

Adsorption of fluoride onto magnesia-Equilibrium and thermodynamic study

476

        IPC Code: B01D15/00

 

        V Aravind & K P Elango

 

 

Complexometric determination of palladium(II) using ethanethiol as a selective masking agent

484

        IPC Code: C22B1/244

 

        J Karthikeyan, P Parameshwara, A Nityananda Shetty & Prakash Shetty

 

 

Citronellol dehydrogenation over copper-magnesium oxide catalyst

488

        IPC Code: C07B35/04

 

        Gulin Selda Pozan & Ismail Boz

 

Vapour phase methylation of phenol over nanocrystalline ZnFe2-xAlxO4 (x = 0, 0.25, 0.5, 0.75 and 1.0) ferrospinel system

 

493

        IPC Code: C07B37/00

 

        Vanga S Reddy, A RadheShyam, R Dwivedi, A Rai, M Anilkumar, V R Chumbale,  A S Aswar & R Prasad

 

 

Catalytic wet oxidation of phenol and its derivatives with Fe2O3 and MnO2

499

        IPC Code: C07C27/10, C07C39/04

 

        Suranjana Chaliha & Krishna G Bhattacharyya

 

 

Optimization of Karanja oil transesterification

505

        IPC Code: C11C3/02

 

        N Prakash, A Arul Jose, M G Devanesan & T Viruthagiri

 

 

Inhibitory action of 2-hydroxy-1-naphthaldehyde glycine and 2-hydoxy-1-naphthaldehyde on the corrosion of mild steel in hydrochloric acid

 

510

        IPC Code: C23F11/00

 

        B I Ita

 

 

Notes

 

 

A modified domestic microwave oven and its use in saponification of oils and fats under normal pressure

 

515

        IPC Code: C11D

 

        Xianying Shi, Junfa Wei & Yuanyuan Bi

 

 

Scalable synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent free condition

519

        IPC Code: C07D239/00

 

        Dolly Kataki, Pranita Chakraborty, Pubalee Sarmah & Pradeep Pukan

 

 

 

Chem-Tech Scan

 

523

Author Index

 

527

Keyword Index

 

528

Guidelines for Authors

529

 

 

 

 

  

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 433-439

 

Modelling of the displacement washing of pulp fibre bed

 

Shelly Arora, S S Dhaliwal & V K Kukreja*

 

The mechanism of the displacement washing of the bed of pulp fibres is mathematically modelled using a single parameter namely, Peclet number. The bulk fluid concentration is assumed to be the function of washing period and position in the bed. The effect of Peclet number on exit solute concentration is shown using the breakthrough curves. A non-linear adsorption isotherm (Langmuir) is used to describe the relationship between bulk fluid concentration and the concentration of solute accumulated on the particle surface. The validity of the model is shown using the literature data. A comparison of washing behaviour of pulp fibres and static bed of glass beads is also presented.

Keywords: Langmuir isotherm, Peclet number, Axial dispersion model, Orthogonal collocation on finite elements, Exit solute concentration

IPC Code: D21C9/02

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 440-447

 

Simultaneous heat and mass transfer studies in drying ammonium

chloride in a batch-fluidized bed dryer

 

R Kumaresan & T Viruthagiri*

 

Simultaneous heat and mass transfer occurs during drying. Fluidized bed drier, unlike other types of dryers is more sensitive to the variation of moisture content of the material being dried. Ammonium chloride is used for this study. Heat and mass transfer studies were carried out using the experimental set up which consists of a well-insulated glass fluidized column with calming section and a fluidized section of height 435 mm and diameter 55 mm. Experiments were carried out with the variables- (i) size of ammonium chloride particles from 495 to 912 microns, (ii) inlet air velocity from 1.136 to 1.391 m/s, (iii) temperature of inlet air to the fluidized bed dryer from 60 to 75°C, (iv) initial moisture content of ammonium chloride to the fluidized bed dryer from 0.04 to 0.06 kg of water /kg of bone dry ammonium chloride, (v) bed hold of 0.090 to 0.130 kg. Humidity of the inlet air to the fluidized bed is determined by measuring the dry and wet bulb temperatures and using the psychrometric chart. Microsoft Excel spreadsheets are used for the calculations. A correlation between Nusselt number and Reynolds number was developed using the least square method. A simplified unsteady state mass transfer equation was developed to determine the diffusion coefficient.

Keywords: Fluidized bed dryer, Ammonium chloride, Simultaneous heat and mass transfer

IPC Code: C09K5/00, B01J8/00

 

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 448-454

 

 

Hydrophobic flocculation characteristics of calcite and effects of
some inorganic dispersants

H Ucbeyiay & A Ozkan*

 

 

Hydrophobic flocculation characteristics of calcite mineral were investigated using sodium dodecyl sulphate (SDS) and Aero 845. Calcite suspensions could be flocculated by these anionic surfactants in the pH range of 9.3-11.5. Especially SDS was more effective on the calcite suspensions at pH values lower than 10.5. The flocculation of calcite with SDS and Aero 845 increased rapidly with increasing surfactant concentration. However, it started to decrease at concentrations higher than 30 mg/L for Aero 845 and 50 mg/L for SDS. It was found that the maximum aggregation degree of calcite particles could be achieved with a stirring speed of 500 rpm and a flocculation time of 3 min. The effects of sodium silicate, sodium polyphosphate and sodium phosphate, used as inorganic dispersants, on the flocculation of calcite were also studied. In the presence of sodium silicate and sodium polyphosphate, the flocculation power values obtained with both surfactants decreased with increasing dispersant concentration till approximately 0.5 and 1 g/L concentrations, respectively. Also, the flocculation of calcite with Aero 845 and SDS decreased towards 0.5 and 1 g/L concentrations of sodium phosphate, respectively. At higher dispersant concentrations, these power values remained relatively constant for sodium silicate, and different effects were also observed for other dispersants depending on surfactant type used in the experiments. In addition, it was found that sodium silicate was more effective to disperse the calcite suspensions with SDS and Aero 845.

Keywords: Calcite, Hydrophobic flocculation, Sodium dodecyl sulphate, Aero 845, Dispersant

IPC Code: C02F1/52

 

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 455-458 

 

An easy spectrophotometric determination of selenium using

azure B as a chromogenic reagent

 

Mendalin Mathew & Badiadka Narayana*

 

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of trace amounts of selenium in water samples, soil, plant materials and human hair. The proposed method is based on the reaction of selenium with potassium iodide in acidic medium to liberate iodine. The liberated iodine bleaches the violet colour of azure B, which is measured at 644 nm. This decrease in absorbance is directly proportional to selenium concentration. Beer’s Law was obeyed in the range 2.0-10.0 µgmL-1 of selenium. The molar absorptivity, Sandell’s sensitivity, quantitation limit and detection limit of the method were found to be 0.9473 ´ 10 5 L mol -1 cm -1, 8.33 ´ 10-4 µg cm–2, 0.070 µgmL-1 and 0.023 µgmL-1, respectively. The proposed method has been successfully applied to the determination of selenium in various samples.

Keywords: Selenium determination, Spectrophotometry, Azure B

IPC Code: C01B19/00, G01J3/00

 

 

Indian Journal of Chemical Technology

ol. 13, September 2006, pp. 459-463

 

 

Reversible inhibition of polyphenol oxidase from apple using

L-cysteine

 

R N Gacche*, A M Shete, N A Dhole & V S Ghole

 

Alternate strategies for prevention of enzymatic browning of fruits and vegetables are required by food industries due to restrictions and several negative health attributes of sulphites, which are effective inhibitors of enzymatic browning reaction. These reactions result mostly from polyphenol oxidase (PPO). The present study was conducted to evaluate the antioxidant and PPO inhibitory potential of L-cysteine. Studies have revealed that with increase in concentration of L-cysteine there was corresponding decrease in the rate of browning reaction and the activity of PPO. The kinetic study indicates that PPO inhibition by L-cysteine is non-competitive. The results suggest that the L-cysteine is a time bound inhibitor of PPO, since its highest concentration (5 mM) gives protection up to 4 h having no further effect on the rate of browning reaction in apple juice. The assessment of radical-scavenging ability of L-cysteine demonstrated that it has high affinity towards a stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·).

Keywords: Polyphenol oxiadse, Enzymatic browning, L-Cysteine, Antioxidant

IPC Code: C12N9/00

 

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 464-469

 

Application of chitosan and alginate in treating waste water
containing heavy metal ions

 

Yimin Qin*, Bingbing Shi & Jingjie Liu

 

The use of sodium alginate and chitosan in treating waste water containing heavy metal ions has been studied in this paper. The effect of the concentration and ratio of chitosan and sodium alginate, treatment temperature and time on the efficiency of Cu(II) ion removal was investigated. Results showed that when used in combination, sodium alginate and chitosan were effective in removing Cu(II) ions from waste water. The treatment was applied to other heavy metal ions such as cadmium, lead and silver ions, and the treatment efficiency was compared. Results showed that when used in combination, the separation of polymeric absorbents from waste water is better than when chitosan and sodium alginate are used alone.

Keywords: Sodium alginate, Chitosan, Heavy metal ions, Waste water treatment

IPC Code: C02F1/00, C02F1/62

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 470-475

 

Diacetylmonoxime-(p-anisyl)-thiosemicarbazone as a new chromogenic reagent for determination of thallium

 

Anitha Varghese & A M A Khadar*

 

A simple and sensitive derivative spectrophotometric method has been developed for the determination of thallium(III) using a newly synthesized reagent diacetylmonoxime-(p-anisyl)-thiosemicarbazone in acetic acid medium. The molar absorptivity and Sandell’s sensitivity of the coloured species are 5.6´104 L mol-1 cm-1 and 3.6 ng cm-2, respectively. Beer’s law is obeyed between 0.25 and 2.60 mg mL-1 of Tl(III) at 460 nm. The stoichiometry of the complex was found to be 1:2 (metal: ligand). Calibration graphs were derived by measuring first order derivative amplitudes at 425 and 505 nm. The metal ions like Cu(II), Cd(II), Pb(II), Zn(II) and Bi(III) which are usually associated with thallium containing samples do not interfere. The developed procedure has been successfully applied for the trace level determination of thallium in minerals, alloys, urine, soil and water samples.

Keywords: Thallium, Diacetylmonoxime-(p-anisyl)-thiosemicarbazone, Derivative spectrophotometry, Minerals

IPC Code: C22B61/00

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 476-483

 

Adsorption of fluoride onto magnesia-Equilibrium and thermodynamic study

 

V Aravind & K P Elango*

 

Batch sorption system using magnesium oxide as an adsorbent was investigated to remove fluoride ions from aqueous solutions. The system variables studied include initial concentration of the sorbate, agitation time, adsorbent dose, pH, co-ions and temperature. The experimental data fitted well to the Freundlich isotherm while, poorly to the Langmuir isotherm. Thermodynamic parameters such as DHo, DSo and DGo were calculated indicating that the adsorption was a spontaneous, endothermic and a physical process. Kinetic studies reveal that the adsorption is first order. A mechanism involving three stages (external surface adsorption, intraparticle diffusion and final equilibrium) has been proposed for the adsorption of fluoride ions onto MgO. XRD patterns of the adsorbent were recorded to get a better in sight into the mechanism of the adsorption process.

Keywords: Defluoridation, Isotherm, Adsorption

IPC Code: B01D15/00

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 484-487

 

 

Complexometric determination of palladium(II) using ethanethiol
as a selective masking agent

 

J Karthikeyan, P Parameshwara, A Nityananda Shetty* & Prakash Shetty

 

A complexometric method based on the selective masking property of ethanethiol towards palladium(II) is proposed. In presence of diverse metal ions, palladium(II) is complexed with excess EDTA and the surplus EDTA is backtitrated with standard zinc sulphate solution at pH 5-5.5 (acetic acid-sodium acetate buffer) using xylenol orange as indicator. An excess of a 0.1% aqueous solution of ethanethiol is then added to displace EDTA from Pd(II)-EDTA complex. The released EDTA is titrated with the same standard zinc sulphate solution as before. Reproducible and accurate results are obtained in the concentration range of 0.5-14.26 mg of palladium with relative error of ±0.40% and coefficient of variation not exceeding ±0.34%. The effect of diverse ions is studied. The method has been used for the determination of palladium in its complexes, catalysts and synthetic alloy mixtures.

Keywords: Complexometry, Masking reagent, EDTA titration, Ethanethiol, Palladium determination

IPC Code: C22B1/244

 

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 488-492

 

Citronellol dehydrogenation over copper-magnesium oxide catalyst

Gülin Selda Pozan* & Ismail Boz

 

Dehydrogenation of citronellol (3,7-dimethyl-6-octene-1-ol) was performed on a copper and alkaline-earth oxide catalyst. CuO/MgO catalysts were prepared by co-precipitation method and were characterized by X-ray diffraction, temperature programmed reduction, and BET surface area. On CuO/MgO catalyst, the main path of reaction is the dehydrogenation of citronellol to citronellal. The dehydrogenation reaction was carried out at atmospheric pressure in a batch reactor at 215°C. Support exhibited varying promoting effects both on the activity and the selectivity to citronellal. Alkaline-earth oxide support has changed surface area of copper oxide catalysts and the phase compositions of copper.

Keywords: Dehydrogenation, Citronellal, Copper alkali oxide catalyst, TPR, XRD, Catalyst characterization

IPC Code: C07B35/04

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 493-498

 

Vapour phase methylation of phenol over nanocrystalline

ZnFe2-x AlxO4 (x = 0, 0.25, 0.5, 0.75 and 1.0) ferrospinel system

 

Vanga S Reddy, A RadheShyam, R Dwivedi, A Rai, M Anilkumar, V R Chumbale, A S Aswar & R Prasad*

 

The alkylation of phenol with methanol was carried out over ZnFe2-xAlxO4 (x = 0, 0.25, 0.5, 0.75 and 1.0) type spinel systems in a fixed bed, down flow reactor. The influence of surface acidity, cation distribution in the spinel lattice and various reaction parameters are discussed. A maximum yield of 70.9 and 22.9% with selectivity of 73.5 and 23.3% was obtained for 2,6-xylenol and o-cresol respectively, giving a total ortho selectivity of 96.8% over ZnFeAlO4 at 350oC, methanol to phenol molar ratio of 5 and WHSV of 0.6 h–1. Catalyst characterization was made by XRD, Mössbauer spectroscopy, ammonia desorption and BET surface area measurements. Mössbauer spectroscopy reveals isomorphic substitution of Fe3+  by smaller Al3+ into the octahedral sites leading to lattice distortion, unsymmetrical charge distribution and charge transfer from iron to oxygen making it more basic and proton attracting. This helps vertical adsorption of phenol and formation of 2,6-xylenol. It has been concluded that catalyst acidity plays major role in the reaction as compared to surface area.

Keywords: Ferrospinels, Consecutive methylation, Vertical and horizontal adsorption

IPC Code: C07B37/00

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 499-504

 

Catalytic wet oxidation of phenol and its derivatives with Fe2O3 and MnO2

 

Suranjana Chaliha & Krishna G Bhattacharyya*

 

Wet oxidation of phenol, 2-chlorophenol, 4-chlorophenol and 2-nitrophenol over iron oxide and manganese dioxide catalysts was tested in this work with or without hydrogen peroxide in the reaction mixture. Influence of factors such as catalyst load, reactant-hydrogen peroxide mole ratio, and reaction time was monitored for all the phenols. Increase in the amount of hydrogen peroxide in the feed composition resulted in a better conversion in all the cases and by using 5 – 10 moles of hydrogen peroxide for each mole of the reactant, conversion was better than 80%. The oxidation reaction was sufficiently fast except in the case of 2-nitrophenol. The wet oxidation could be carried out in air by using either iron oxide or manganese dioxide catalyst without adding hydrogen peroxide to the reaction mixture. The direct oxidation is more effective for 2-chlorophenol and 4-chlorophenol with iron oxide while manganese dioxide was more effective for phenol,
2-chlorophenol and 4-chlorophenol. In both cases, 2-nitrophenol was found to be more resistant to oxidation.

Keywords: Wet oxidation, Phenol, Chlorophenol, Nitrophenol, Iron oxide, Manganese dioxide, Hydrogen peroxide

IPC Code: C07C27/10, C07C39/04

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 505-509

 

Optimization of Karanja oil transesterification

 

N Prakash*, A Arul Jose, M G Devanesan & T Viruthagiri

 

Production of biodiesel through transesterification of Karanja (Pongamia pinnata) oil was studied. The Karanja oil was treated with a lower alcohol (methanol) in the presence of a base catalyst (KOH) to yield methyl esters of fatty acids (biodiesel) and glycerin. The influences of reaction temperature, molar ratio of alcohol to oil, amount of catalyst and reaction time on the product yield were studied. The optimal combination of operating parameters for maximum yield was found out using Taguchi’s method. The performance and emission tests were carried out in a four stroke single cylinder, Kirloskar Av1 D.I.Engine. Different blends of biodiesel with conventional diesel were tested. The results show an appreciable reduction in emission level and marginal increase in performance when compared with sole fuel. The results concluded that the biodiesel from Karanja oil can be used as an effective alternate in existing diesel engines without any engine hardware modifications.

Keywords: Biodiesel, Karanja oil, Transesterification

IPC Code: C11C3/02

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 510-514

 

Inhibitory action of 2-hydroxy-1-naphthaldehyde glycine and
2-hydroxy-1-naphthaldehyde on the corrosion of mild steel in hydrochloric acid

B I Ita

 

The effects of 2-hydroxy-1-naphthaldehyde glycine (HNG) and 2-hydroxy-1-naphthaldehyde (HN) on the corrosion of mild steel in hydrochloric acid have been studied. Weight loss measurements reveal that HNG exhibits higher inhibition efficiency than HN. Generally, inhibition was found to increase with increase in inhibitor concentration and temperature. Chemical adsorption mechanism has been proposed for the inhibitors. The inhibitors obey Langmuir adsorption isotherm at higher concentration and temperature. The difference in the inhibition behaviour of the compounds has been explained in terms of the solubility of the compounds and strength of the inhibitor-metal bond rather than difference in molecular weights alone.

Keywords: Corrosion inhibition, Napthaldehyde, Glycine, Mild steel, Chemisorption

IPC Code: C23F11/00

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 515-518

 

A modified domestic microwave oven and its use in saponification of oils and fats under normal pressure

Xianying Shi, Junfa Wei* & Yuanyuan Bi

 

A modified domestic microwave oven equipped with an electromagnetic stirrer and a condenser has been described and its use in the saponification of oils and fats, such as vegetable oil, cattle fat, and pig fat, has been investigated under normal pressure. The experimental results showed that using the improved domestic microwave, which enables two common experimental operations—stirring and refluxing, the saponification rate is rapid with high yield. Accordingly, on the basis of exciting outcome, it can be deduced preliminarily that the modified device is suitable to most of the chemosynthetic experiments.

           Keywords: Microwave oven, Saponification

           IPC Code: C11D

 

Indian Journal of Chemical Technology

Vol. 13, September 2006, pp. 519-521

 

Scalable synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent free condition

 

Dolly Kataki, Pranita Chakraborty, Pubalee Sarmah & Prodeep Phukan*

 

An improved solvent free, one pot procedure for the synthesis of 5-ethoxycarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones catalyzed by iodine is developed. The process has been utilized successfully in large-scale synthesis of Biginelli products.

           Keywords: Iodine, Aldehyde, Ethyl acetoacetate, Urea, Dihydropyrimidin-2(1H)-one, Solvent free condition

           IPC Code: C07D239/00