Indian Journal of Chemical Technology

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VOLUME 14

NUMBER 4

JULY 2007

CODEN:ICHTEU

 

ISSN:0971-457X

 

CONTENTS

 

Papers

 

 

Multistep model predictive control of ethyl acetate reactive distillation column

333

        IPC Code(s): B01D3/26, C07C

 

        P V S Ravi Chandra & Ch. Venkateswarlu

 

 

Predictive controller design for non-linear chemical processes

341

        IPC Code(s): B01

 

        N Sivakumaran & T K Radhakrishnan

 

 

Study on defluoridation of drinking water using zirconium ion impregnated activated charcoals

350

        IPC Code(s): A23L2/00, G01N33/18

 

        C Janardhana, G Nageswara Rao, R Sai Sathish, P Sunil Kumar, V Anil Kumar &
M Vijay Madhav

 

 

Fluoride removal by mixtures of activated carbon prepared from Neem (Azadirachta indica) and Kikar (Acacia arabica) leaves

 

355

        IPC Code(s): B01D15/00, C01B31/00

 

        Sunil Kumar, Asha Gupta & J P Yadav

 

 

Recovery of metal ion from micellar solution

362

        IPC Code(s): C02F1/42, C22B3/42

 

        Rahul Gawale & K V Marathe

 

 

Ammoxidation of methylaromatics over VPO/SiO2 catalysts

371

        IPC Code(s): B01J21/06, C07C255/00

 

        Xie Guang-yong & Huang Chi

 

 

Corrosion inhibition of stainless steel 347 in the mixture of phosphoric and acetic acid using phosphorus ylide compound

 

376

        IPC Code(s): C23F11/00

 

        S M A Hosseini, M Quanbari & M Salari

 

 

Corrosion inhibition by sodium potassium tartrate-Zn2+ system for carbon steel in rainwater collected from roof top

 

382

        IPC Code(s): C23F11/00

 

        J Arockia Selvi, S Rajendran & A John Amalraj

 

 

Studies on use of lignocellulosic residues of palma rosa grass after steam distillation for the production of chemical grade pulp

 

389

        IPC Code(s): D21C3/00, C08L97/02

 

        Dharm Dutt, C H Tyagi, A K Upadhyaya & A P Garg

 

Assessment of the movement of some dithiocarbamate fungicides by soil thin-layer chromatography

 

400

        IPC Code(s): B01D15/08

 

        H S Rathore, G Varshney & K Ishratullah

 

 

Retention behaviour of synthetic dyes on coconut oil impregnated egg shell layers in pure and mixed solvent systems

 

407

        IPC Code(s): C09B57/00

 

        Aditya Kumar Misra

 

 

Spectrophotometric determination of hydroxylamine and its derivatives in drug formulation using methyl red

 

412

        IPC Code(s): A61K, G01J3/00, C07C215/00

 

        Mary George, N Balasubramanian & K S Nagaraja

 

 

Simultaneous kinetic spectrophotometric determination of citric and ascorbic acid by H-point standard addition method

 

417

        IPC Code(s): G01J3/00, C07C59/265, C07D307/62

 

        Kobra Zarei, Morteza Atabati & Najmeh Karimian

 

 

Synthesis and characterization of a new phase of titanium phosphate and its application in separation of metal ions

 

423

        IPC Code(s): B01D15/04, C01G23/00

 

        Kalpana Maheria & Uma Chudasama

 

 

Notes

 

 

Differential pulse polarographic trace level determination of iodate

427

        IPC Code(s): C25B1/04, G01N27/48

 

        P Sharma & S Songara

 

 

Removal of fluoride from commercial Syrian wet phosphoric acid by precipitation

430

        IPC Code(s): C01B9/08, C01B25/18

 

        M A Abdulbaki

 

 

Author Index

 

433

Keyword Index

 

434

Guidelines for Authors

435

 

 

 

 

 

 

 

 

 

 

 

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 333-340

 

Multistep model predictive control of ethyl acetate reactive distillation column

 

P V S Ravi Chandra & Ch. Venkateswarlu*

 

An unconstrained model predictive control (MPC) strategy is presented for single input-single output (SISO) control of a reactive distillation column. The predictive model of the MPC is based on the autoregressive moving average (ARX) model structure, whose parameters are updated on-line using the process measurement information. The design and performance of the control strategy is evaluated by applying to a highly nonlinear ethyl acetate reactive distillation column with double feed column configuration involving an esterification reaction with azeotropism. The controller performance is studied with respect to the effect of tuning parameters involved in the ARX model parameter adaptation algorithm and also towards the influence of model prediction and control horizons. The simulation results illustrate the superior performance of the multistep model predictive control strategy over the conventional PI controller for both setpoint tracking as well as disturbance rejection.

Keywords: Reactive distillation, PI control, Model predictive control

IPC Code(s): B01D3/26, C07C

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 341-349

 

Predictive controller design for non-linear chemical processes

N Sivakumaran & T K Radhakrishnan*

 

This paper focusses on the design of Dynamic Matrix Control (DMC) for non-linear systems in real time using Matlab and dSPACE interfacing card. A pH neutralization and quadruple tank process are considered here for predictive control, based on the system matrix formulation using data obtained from real time, for which, linear optimization based constrained controller design is performed. The controller effort weighing (l) and number of predictions steps (P) are tuned for the systems in real time. The systems are analyzed for reference tracking and disturbance rejection behaviour.

Keywords: Dynamic matrix control, Interfacing and optimization

IPC Code(s): B01

 

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 350-354

 

Study on defluoridation of drinking water using zirconium ion impregnated activated charcoals

C Janardhana*, G Nageswara Rao, R Sai Sathish, P Sunil Kumar, V Anil Kumar & M Vijay Madhav

 

Activated charcoals which are effective for fluoride removal, when impregnated with zirconium metal ions have an increase in their fluoride adsorption capacity by 3 to 5 times to that of plain activated charcoal. Continuous down flow adsorption mode at room temperature was adopted to defluoridate drinking water. Three columns were prepared by the impregnation of ZrOCl2 in groundnut shell, coconut shell and coconut fiber activated charcoals. The column was run at a constant rate of 0.6-0.7 L/h with known fluoride influent water and a constant level of water was maintained. Treated water samples were analysed by the ion selective electrode method. In this study zirconium ion impregnated coconut fiber charcoal (ZICFC) showed maximum fluoride uptake and proved to be the most effective defluoridating agent followed by groundnut shell and coconut shell charcoals. ZICFC was effective for 21 liter lots of (8.0 mg F- ion/L) test solution and 6 liter lots of (2.47 mg F ion/L) tap water, where the fluoride concentration in each of these liter lots is less than 1.5 mg/L.

Keywords: Activated charcoals, Continuous flow method, Defluoridation, Zirconium oxychloride

IPC Code(s): A23L2/00, G01N33/18

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 355-361

 

Fluoride removal by mixtures of activated carbon prepared from Neem (Azadirachta indica) and Kikar (Acacia arabica) leaves

Sunil Kumar, Asha Gupta & J P Yadav*

 

Fluoride removal from aqueous solution was investigated using activated carbon developed from mixture of Neem (Azadirachta indica) and Kikar (Acacia arabica) leaves. In this study, the mixture of sizes 0.3 mm and 1.0 mm (1:1, 2:1 and 1:2) adsorbent were prepared by mixing the thermally activated Neem (Azadirachta indica) leaves carbon and thermally activated Kikar (Acacia arabica) leaves carbon, according to their efficiency for fluoride removal. Batch type experiment was carried out for the adsorption of fluoride using mixture adsorbent. In the batch study influence of pH, adsorbent dose and contact time were investigated. Adsorption of fluoride was pH dependent and was found to be maximum at pH 6. Fluoride removal increased with increased dose of carbon. The adsorption process obeyed Freundlich adsorption isotherm, Langergren’s equation and intraparticle diffusion. Fluoride removal increased with decreasing particle size of carbon. In mixture, adsorbent ratio 2:1 had slightly higher capacity than the 1:1 and 1:2.

Keywords: Fluoride, Adsorption, Thermally activated carbon, Azadirachta indica, Acacia arabica

IPC Code (s): B01D15/00, C01B31/00

 

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 362-370

 

 

Recovery of metal ion from micellar solution

 

Rahul Gawale & K V Marathe*

 

Separation of cobalt (II) from micellar (surfactant) solution was carried out by using strongly acidic cation exchange resin Indion 225H and chelating resin Duolite C467. The equilibrium data obtained in this study fits in Langmuir adsorption isotherm for Indion 225H resin and Freundlich adsorption isotherm for Duolite C467 resin. The effect of pH, temperature and feed concentration on the adsorption capacity of the resins was studied. For both the resins, diffusion of cobalt in the resin phase is a rate controlling step. The dynamic behaviour of the adsorption column was also modeled using equilibrium and kinetic data. Column studies were simulated by using linear driving force model. Desorption of cobalt from chelating resin was easier than strongly acidic cation exchange resin.

Keywords: Ion exchange resins, Adsorption, Effective diffusivity, Cobalt recovery

IPC Code(s): C02F1/42; C22B3/42

 

 

Indian Journal of Chemical Technology

Vol. 14, July  2007, pp. 371-375

 

Ammoxidation of methylaromatics over VPO/SiO2 catalysts

Xie Guang-yong* & Huang Chi

 

Ammoxidation of methyl aromatics to their corresponding nitriles over silica-supported vanadium phosphorus oxide (VPO/SiO2) catalysts has been studied. The effects of carrier silica, the addition of phosphorus, the substituents and the loadings on catalytic performances have been discussed. Compared with unsupported VPO, the VPO/SiO2 catalysts have higher catalytic activity for ammoxidation of substituted toluenes at much lower reaction temperature. XPS shows that vanadium and phosphorus exist mainly in the pentavalent state in the VPO/SiO2 catalysts. XRD shows that vanadium phosphorus oxides exist as amorphous phase in 10 wt.% catalyst. When the loadings are over 10 wt.%, the crystalline
a-VOPO4 would emerge, which would decrease the yield and selectivity. Additional phosphorus can inhibit the formation of crystalline V2O5 and form amorphous composite oxides with vanadia, which play concerted catalytic function and increase the selectivity of nitriles remarkably. The methyl aromatics with different substituents or same substituents on diffetent positions have different catalytic activities because of the variant electronic stability of intermediates, the hindered accessibility of methyl group or the chemisorption state of the substrate molecule on the electrophilic catalyst surface.

Keywords: Ammoxidation, VPO/SiO2 catalyst, Methylaromatics, Aromatic nitriles

IPC Code(s): B01J21/06, C07C255/00

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 376-381

 

Corrosion inhibition of stainless steel 347 in the mixture of phosphoric and acetic acid using phosphorus ylide compound

S M A Hosseini*, M Quanbari & M Salari

 

Cathodic and anodic polarization behaviour of SS347 in mixture of highly concentrated phosphoric and acetic acid in the presence of various amounts of dimethyl 2-(2-hydroxyphenyl amino)-3-(tri phenylPhosphoranylidene) butanedioate (L-OH) at different temperatures (20, 30, 40, 50±1°C) have been investigated potentiodynamically. The cathodic and anodic Tafel slopes values calculated from the polarization curves indicate that the corrosion rate decreases with increasing L-OH concentration. The corrosion potential (Ecorr) and passive potential (Ep) increased (shifted slightly toward positive potential) while corrosion current density (Icorr) and passivation current (Ip) decreased with increasing L-OH amount. Critical potential for passivity (Ecr) did not show any remarkable change but critical current density (Icr) often decreased with increasing L-OH concentration. Maximum inhibition efficiency (95%) is obtained for the alloy in acid solution containing 60 ppm of L-OH. The open circuit potential after polarization attained positive value indicating formation of passive film on the surface of experimental sample. Activation energy (Ea) and Gibbs free energy (Gads) for adsorption of L-OH are calculated. The values of Gads decreased (attained more negative values) with increasing temperatures.

Keywords: Corrosion inhibitor, Polarization behaviour, L-OH, Isotherm

IPC Code (s): C23F11/00

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 382-388

 

Corrosion inhibition by sodium potassium tartrate-Zn2+ system for carbon steel in rainwater collected from roof top

J Arockia Selvi, S Rajendran* & A John Amalraj

 

A synergistic effect exists between sodium potassium tartrate (SPT) and Zn2+ in controlling corrosion of carbon steel immersed in rain water collected from roof top and stored in concrete tank. The formulation consisting of 50 ppm of SPT and 25 ppm of Zn2+ has 91% corrosion inhibition efficiency (IE). As the immersion period increases IE decreases. Polarization study reveals that SPT-Zn2+ system functions as a mixed inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. FTIR spectra indicate that the protective film consists of Fe2+-SPT complex and Zn(OH)2. A formulation consisting of 50 ppm of SPT, 25 ppm of Zn2+ and 50 ppm of a biocide, N-cetyl-N,N,N-trimethyl ammonium bromide, has 98% corrosion inhibition efficiency and 100% biocidal efficiency.

Keywords: Carbon steel, Corrosion inhibition, Synergistic effect, Mixed inhibitor, Surfactants

IPC Code(s):  C23F11/00

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 389-399

 

Studies on use of lignocellulosic residues of palma rosa grass after steam distillation for the production of chemical grade pulp

Dharm Dutt*, C H Tyagi, A K Upadhyaya & A P Garg

 

The study aims at using of lignocellulosic residues of Cymbopogon martini to develop value added quality papers by eco-friendly pulping and bleaching techniques. C. martini grass is exclusively used to extract important geranium oil by distillation in crude direct–fired stills. Anatomical, morphological and chemical studies indicate its similarities with hardwoods and its suitability for the production of chemical grade pulp. Molecular oxygen, which is specific oxidizing agent for lignin has an immediate drawback to its use, is the low solubility in cooking liquor. The diffusion problem of dissolved oxygen is reduced to insignificance because of looser and open structure in the lignocellulosic residues of C. martini after distillation. Distillation process makes the C. martini suitable for alkali-O2 delignification process by bridging over the problem of mass transfer of O2, which is far less than C. martini without distillation. C. martini produces 44.73% screened pulp yield at kappa number 22.12 by soda cooking process and screened pulp yield of 45.80% at kappa number of 20.47 by alkali-O2 delignification process. The addition of 0.1% AQ in alkali-O2 process reduces kappa number to 17.35 and improves pulp yield by 1.20%. The unbleached pulp shows good response towards bleaching, which can be bleached up to 85.95% by OCEHH bleaching sequence.

Keywords: Cymbopogon martini, Steam distillation, Lignocellulosic residues, Soda and alkali-O2 pulping, Bleaching

IPC Code(s): D21C3/00, C08L97/02

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 400-406

 

Assessment of the movement of some dithiocarbamate fungicides by soil
thin–layer chromatography

H S Rathore*, G Varshney & K Ishratullah

 

The paper describes the mobility of dithiocarbamate fungicides such as mancozeb, sodium diethyldithiocarbamate, ziram, propineb and zineb on chromatoplates coated with different types of soil and admixtures of charcoal – soil in water, aqueous solutions and organic solvents. It also comprises the results of adsorption of these fungicides obtained by batch process. The results so obtained are discussed for use in the control or deactivation of dithiocarbamate fungicides translocation from soil to plant.

Keywords: Adsorption, Charcoal, Deactivation, Fungicide, Mobility, Soil, TLC

IPC Code (s): B01D15/08

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 407-411

 

 

Retention behaviour of synthetic dyes on coconut oil impregnated egg shell layers in pure and mixed solvent systems

Aditya Kumar Misra*

 

The retention behaviour of twenty four anionic, cationic, sulphonated and amphoteric synthetic dyes has been examined on plain and coconut oil impregnated egg shell layers using pure methanol, pure acetonitrile and methanol-water, acetonitrile-water, acetonitrile-methanol and acetonitrile-acetone mixed mobile phases. The mobile phase composition and the effect of solubility of dyes on hRf values have been discussed. The mechanism of migration is explained in terms of partition on impregnated egg shell layers and the polarity of the mobile phase used.

The acetonitrile-acetone (75:25) system was found to be most effective and gave several quaternary separations of dyes. A large number of separations of same coloured dyes as well as having approximately similar structural formula have been achieved. The separation of acidic dyes from basic dyes; acidic dyes from acidic dyes; and acidic dyes from amphoteric dyes are of special interest.

Keywords: TLC, Synthetic dyes, Impregnated layers, Coconut oil, Mixed solvent systems

IPC Code(s): C09B57/00

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 412-416

 

Spectrophotometric determination of hydroxylamine and its derivatives in drug formulation using methyl red

 

Mary George, N Balasubramanian & K S Nagaraja*

 

Hydroxylamine has been determined by its oxidation to nitrite with a known excess of bromine. Bromine in acidic medium bleaches the dye methyl red. A known excess of bromine when treated with hydroxylamine is reduced to bromide and the unreacted bromine is determined using methyl red. The method obeys Beer’s law in the range 0-5 mg of hydroxylamine in an overall aqueous volume of 25 mL. The relative standard deviation is 2.7% (n=10) at 3 mg of hydroxylamine. The molar absorptivity is calculated to be 9.8´104 Lmol-1cm-1 with the correlation coefficient of 0.995. The developed method bas been applied for the determination of hydroxylamine and its derivatives after hydrolysis in drug formulations. The results obtained by the present method compare well with those obtained by the Verma-Gupta’s method and with the standard addition of hydroxylamine and recovery studies.

Keywords: Spectrophotometry, Hydroxylamine, Bromine, Methyl red

IPC Code(s): A61K, G01J3/00, C07C215/00

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 417-422

 

Simultaneous kinetic spectrophotometric determination of citric and ascorbic acid by H-point standard addition method

Kobra Zarei*, Morteza Atabati & Najmeh Karimian

 

The H-point standard addition method was applied to kinetic data for simultaneous determination of citric and ascorbic acid or selective determination of ascorbic acid in presence of citric acid. The method is based on the difference in the rate of reaction of citric and ascorbic acid with copper(II)-ammonia complex. The linear dynamic ranges for the two analytes of citric and ascorbic acid are 0.80-1.15 ´ 102 and 0.70-10.00 mM, respectively. The proposed method was successfully applied for the determination of citric and ascorbic acid in some powdered drink mixtures and vitamin C tablet.

Keywords: Citric acid, Ascorbic acid, Copper(II)-ammonia complex, H-point standard addition method

IPC Code (s): G01J3/00, C07C59/265, C07D307/62

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 423-426

 

Synthesis and characterization of a new phase of titanium phosphate and its application in separation of metal ions

Kalpana Maheria & Uma Chudasama*

 

Amorphous Titanium Phosphate (TiP), an inorganic ion exchanger of the class of tetravalent metal acid (tma) salts has been synthesized by sol-gel method. TiP has been characterized by elemental analysis (ICP-AES), spectral analysis (FT-IR), thermal analysis (TGA and DSC) and X-ray diffraction studies. Chemical resistivity of the material has been assessed in various media- acids, bases and organic solvents. The Na + ion exchange capacity (IEC) has been determined and effect of heating on IEC studied. The distribution and elution behaviour of TiP towards several metal ions has been studied in different electrolyte media/concentrations. Based on the distribution studies a few binary metal ion separations have been achieved.

Keywords: Titanium phosphate, Inorganic ion exchanger, Tetravalent metal acid salts, Distribution coefficient, Metal separations

IPC Code(s): B01D15/04, C01G23/00

 

 

Indian Journal of Chemical Technology

Vol. 14 July, 2007, pp. 427-429

 

Differential pulse polarographic trace level determination of iodate

P Sharma* & S Songara

 

A detailed voltammetric study was carried out for iodate ion which has resulted in optimization of analytical conditions for its trace level determination using differential pulse polarographic method. Chlorate and bromate did not interfere. The detection limit was 0.6 µg/mL. The method has successfully been applied for the analysis of iodate in different matrices.

Keywords: Iodate, DPP, Real samples

IPC Code (s): C25B1/04, G01N27/48

 

Indian Journal of Chemical Technology

Vol. 14, July 2007, pp. 430-431

 

Removal of fluoride from commercial Syrian wet phosphoric acid by precipitation

M A Abdulbaki

 

The removal of fluoride from commercial Syrian wet phosphoric acid was studied by precipitation with different sodium and potassium salts under different experimental conditions: stoichiometric ratio, temperature and mixing time. The ideal conditions that give high removal, were determined. All the salts used were found to give high percentage of removal  i.e. 95-97%. But, commercial sodium chloride is recommended due to economical reasons.

Keywords: Phosphoric acid, Precipitation, Fluoride

IPC Code(s): C01B9/08, C01B25/18