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Indian Journal of Chemical Technology

 

 

 

ISSN:0971-457X

 

CODEN:ICHTEU 11(4) 453-600

VOLUME 11

NUMBER 4  

JULY 2004

 

 

CONTENTS

 

Research articles

 

 

Synthesis and evaluation of some organic vapour phase corrosion inhibitors          

459

IPC Code: C23 F 13/00

 

M A Quraishi & D Jamal

 

 

 

Electrodeposition of Zinc-iron alloy                                            

465

IPC Code: C25 D 3/56

 

Visalakshi Ravindran, R Sridevi, R Rajakumari, R Sekar & V S Muralidharan

 

 

 

Selective extractive spectrophotometric determination of cobalt using cyanex 923                      

470

IPC Code: G01 J 3/00, C01 G 51/00

 

Bina Gupta, Akash Deep, Virendra Singh & Shiv N Tandon

 

 

 

A rapid  flame atomic absorption spectroscopic procedure for determination of  lead in aluminium base alloys  

475

IPC Code: G01 J 3/00, C22 C 45/00

 

A S Rao, K K Gupta, J K Sircar & S C Srivastava

 

 

 

Separation of cesium-137 from acidic fission product waste solutions using a complex  inorganic exchanger (ZrP-AMP)        

479

IPC Code: B01 J 39/02

 

V N Reddy, J Satyanarayana, S S Kumar, M V Sivaiah, R M Krishna, S Lakshminarayana & G S Murthy 

 

 

 

Effect of some  electric factors on the  effective oxidation level of  aluminum    

486

IPC Code: G01 N 27/26

 

Peter D Dineff & Emilia K Sabeva

 

 

 

Preparation of a reusable strip of barley oxalate oxidase for determination of urinary oxalate 

495

IPC Code: C03 C 17/22

 

S Madanpotra, R Chaudhary, S Singh & C S Pundir

 

 

 

Studies on PVC based chelating inorganic ion exchange resin membrane sensor for neodymium(III) ion

500

IPC Code: C08 J 5/22

 

A P Gupta, Himanshu Agrawal, S K Shukla & Vikas R Bharduwaj

 

 

 

High performance liquid chromatographic determination of astemizole in pharmaceutical dosage forms

504

IPC Code: B01 D 15/00, A61K

 

K Basavaiah, V S Charan  & U Chandrashekar 

 

 

 

Voltammetric studies of endosulphan                                         

509

IPC Code: A01 N 31/00, G01 N 27/00

 

Sunita Kumbhat & Sushma Dave

 

 

 

Destabilization characteristics of talc in distilled and fresh waters

512

IPC Code: C08 J 3/00, C01 F 5/00

 

A Ozkan

 

 

 

Removal of arsenic from water by different adsorbents              

   518

IPC Code: C02 F 1/28

 

Rajeev Goel, S K Kapoor, Kshipra Misra & R K Sharma

 

 

 

Excess volumes of binary liquid mixture containing methyl butyrate with bromobenzene, chlorobenzene and nitrobenzene at 303K, 308K and 313K                                      

526

IPC Code: G01 N 9/00

 

M V Rathnam & R K Singh

 

 

 

Comparison of SFE, ASE, and soxhlet extraction procedures for the determination of polycyclic aromatic hydrocarbons associated with airborne particulate matter 

  531

IPC Code: C07 C 15/00, B01 D 11/00

 

S M Talebi & A Taebi

 

 

 

Simulation of electro-mixer-settler for the partitioning of uranium and plutonium in PUREX process                                  

535

IPC Code: B01 D 59/38, G06 F 17/00

 

N K Pandey & S B Koganti

 

 

 

Transport of Pu(IV) across supported liquid membrane from nitric acid medium using cyanex- 923 as the mobile receptor

548

IPC Code: C22 B 60/40

 

S R Sawant, J V  Sonawane, Anil Kumar Pabby, A K Venugopalan , P K  Dey &  B Venkataramani

 

 

 

Sequestration and remediation of heavy metals by Brassica sp at  Hindan river sites         

555

IPC Code: (C02 F 3/32, 101:20)

 

Anwar Ahmad & Masood Alam

 

 

 

Design and fabrication of a catalytic reactor for treating automobile exhaust       

560

IPC Code: B01 D 53/34

 

J Soji Adeyinka, J U Okoli & Yousuo Digineni

 

 

 

A facile synthesis of fatty acid esters of para-cresol catalysed by acid activated Indian Bentonite

565

IPC Code: C07 C 67/00, C07 C 39/07, B01 J 21/00

 

B Vijayakumar, Pushpa Iyengar, Gopalpur Nagendrappa  & B S Jai Prakash

 

 

 

Oxidative coupling of methane over La-promoted MgO catalysts: Influence of precursors and method of catalyst preparation

569

IPC Code: B01 J 21/00

 

V R Choudhary, V H Rane & S T Chaudhari

 

 

 

Crystallization of HMX in acetone-water system                        

575

IPC Code: B01 D 9/02

 

Souraseni Basu, N M Gawande, M E Apte & V L Narasimhan

 

 

 

Educator

 

 

 

The nature of heat                                

582

Jaime Wisniak

 

Chem-Tech Scan                                                       

593

Author Index                                                             

597

Keywords Index                                                        

598

 

 

 

 

  

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 459-464

 

Synthesis and evaluation of some organic vapor phase corrosion inhibitors

 M A Quraishi* & D Jamal

 

Five organic volatile corrosion inhibitors (VCIs) were synthesized using 2-Dec-9-enyl-2-imidazoline with various acids such as maleic acid, orthophosphoric acid, nitrobenzoic acid, phthalic acid and cinnamic acid and evaluated as corrosion inhibitors of mild steel, brass and copper by weight loss method. Eschke test method, sodium chloride inoculation test method and sulfur dioxide (SO2) test method were also carried out to investigate the corrosion inhibiting effect of the compounds. All the investigated VCIs exhibited good inhibition efficiency (IE) for all the metals. Cinnamate salt showed best result among all the studied compounds for all the metals.

 

IPC Code: C23 F 13/00

Keywords: Eschke test, volatile corrosion inhibitor, imidazoline derivative, cinnamate salt, mild steel, brass, copper     

 

 

 

Indian Journal of Chemical Technology

Vol. 11, July 2004, pp 465-469

 

Electrodeposition of Zinc-iron alloy

Visalakshi Ravindran*, R Sridevi, R Rajakumari, R Sekar & V S Muralidharan

 

To protect steel against environmental attack, zinc-iron alloy deposition is used.  Search for a noncyanide plating bath resulted in the development of sulphate bath.  Current  efficiency, throwing power and Hull cell studies were used to optimise a plating bath.  The optimized  plating bath  composition  is  zinc sulphate   0.05M, ferrous ammonium sulphate 0.01M,  sodium sulphate   20 g L-1,  boric acid  30 g L-1, methanol  0.12M, triethanolamine  0.2M, ascorbic acid 2.5 mM and sodium lauryl  sulphate 0.06M. Matte white deposits were obtained in the current density range of   2-3 Adm-2.

 

IPC Code: C25 D 3/56

Keywords: Electrodeposition, zinc-iron alloy, sulphate bath, alloy plating, triethanolamine,  non-cyanide     

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 470-474

 

Selective extractive spectrophotometric determination of cobalt using cyanex 923

Bina Gupta*, Akash Deep, Virendra Singh & Shiv N Tandon

 

The present paper describes a selective extractive spectrophotometric method for the determination of Co(II) using toluene solution of cyanex 923. A blue coloured complex (lmax 685 nm) is quantitatively extracted in the organic phase from 7 – 10 mol L-1 HCl. The composition of this complex is proposed as H2CoCl4.2cyanex 923. The Beer’s law is obeyed in the concentration range 0.0 – 4.2 ´ 10-3 mol L-1 Co(II) and the molar absorptivity of the complex is 5.6 ´ 102 L mol-1 cm-1. The presence of hundred fold excess of metal ions such as Mo(VI), W(VI), V(V), Ti(IV), V(IV), Al(III), Cr(III), Fe(III), Mn(II), Fe(II), Ni(II), Cu(II), Zn(II) and Cd(II) and fifty fold of anions namely PO43-, CO32-, SO42-, C2O42-, citrate, tartrate, NO3- and SCN- do not interfere in the determination of Co(II). The accuracy of proposed procedure is checked by assaying the concentration of cobalt in two standard NBS steel samples. The applicability of the method is demonstrated by selective determination of Co(II) in a multi element system like polymetallic manganese sea nodules. The result is in fairly good agreement with those obtained by AAS and ICP-AES.

 

IPC Code: G01 J 3/00, C01 G 51/00

Key words: Cobalt, extractive spectrophotometry, cyanex 923

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 475-478

 

A rapid  flame atomic absorption spectroscopic procedure for determination of lead in aluminium base alloys

AS Rao*, K K Gupta, J K Sircar & S C Srivastava

  

A rapid and sensitive technique to determine lead in trace level present in aluminium based alloys by flame atomic absorption spectroscopic technique (AAS) is described. It is free from aluminium and silicon spectral interferences. The method is free from associated alloying elements. Lead was determined at 283.3 nm using air-acetylene flame. The value of relative standard deviation (r.s.d.) of lead, in  case of high silicon containing samples is found to be 2.545% and that for low ones 10-12% respectively. The standard deviation values were +/- 0.0014 and  +/-0.0016 respectively. A threshold limit of concentration of aluminium and silicon  for the determination of lead in final analyte solution has been described and this has been correlated with the sample weight to be taken for analysis.

 

IPC Code: G 01J 3/00, C22 C 45/00

Keywords: Lead determination, aluminium ally, atomic adsorption spectroscopy

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 479-485

 

Separation of cesium-137 from acidic fission product waste solutions using a complex  
inorganic exchanger (ZrP-AMP)

V N Reddy, J Satyanarayana, S S Kumar, M V Sivaiah, R M Krishna, S Lakshminarayana & G S Murthy 

 

A new inorganic ion exchanger, zirconium phosphate-ammonium molybdophosphate (ZrP-AMP) has been prepared in granular form, suitable for column operation. The results obtained from TG-DTA, IR and X-ray diffraction studies for this exchanger are presented. The kd values for different metal ions were determined and the affinity order was found to be Cs>>Rb>Zr>Ce>rare earths. pH titration curve, breakthrough capacities for cesium in different types of simulated nuclear wastes  and elution of cesium from ZrP-AMP column have been studied.  Conditions for separation and isolation of cesium from other fission products in simulated waste solutions have been established. The exchanger was found to be stable to a g-radiation dose of 108 rads.

 

IPC Code: B01 J 39/02

Keyword: Cesium-137, ZrP-AMP, ion-exchanger, acidic fission product

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 486-494

 

Effect of some electric factors on the effective oxidation level of aluminum

Peter D Dineff & Emilia K Sabeva*

 

In the present work, conditions were set for a study of the effect of field geometrical structure, by its transition from uniform to non-uniform field by varying the ratio of anode and cathode active areas on the effective oxidation level, assumed to be a measure for non-conformity with Faraday law by the anodic dissolution of aluminum in solutions of sodium chloride. Non-conformity with Faraday law was observed as in the range of low current densities (lower than 80-150 Am-2) the effective oxidation level changes in a wide interval depending on the factors studied and electric field geometry; in the range of high current densities (higher than 80-150 Am-2) the effective oxidation level is slightly affected by the electric field geometry and conditions used.

 

IPC Code: G01 N 27/26

Keywords: Electric field geometry, oxidation of aluminum, anodic dissolution

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 495-499

 

Preparation of a reusable strip of barley oxalate oxidase for determination of urinary oxalate

  S Madanpotra, R Chaudhary,  S Singh &  C S Pundir*

 

A reusable plastic strip of oxalate oxidase was prepared by immobilizing covalently, a partially purified barley oxalate oxidase on alkylamine glass beads affixed on a plastic strip with a non-reactive fixative.  The immobilized enzyme  gave a conjugation yield of 9.5 mg g-1 support with 84.8% retention of initial activity of free enzyme. A method for discrete analysis of oxalate in urine was developed employing this enzyme strip. The method is based on measurement of H2O2 generated from urinary oxalate  by strip bound oxalate oxidase by Trinder’s  colour reaction. The minimum detection limit of the method was  0.9 µg 0.1mL-1  urine. The recovery of added oxalate was 84.7%.Within and between assay co-efficient of  variation were <7.3% and <15.6% respectively. A fair correlation (r=0.752) was found  between oxalate values obtained by a commercial kit method. The method provides enormous ease in handling of immobilized enzyme during its reuse and is unaffected by Cl¯ found in biological fluids.

 

IPC Code: C03 C 17/32

Keywords: Oxalate, oxalate oxidase, enzyme strip, urine, Sorghum, alkylamine glass, immobilized enzyme

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 500-503

 

Studies on PVC based chelating inorganic ion exchange resin membrane sensor for neodymium(III) ion

A P Gupta*, Himanshu Agrawal, S K Shukla & Vikas R Bharduwaj

 

Tetracycline sorbed zirconium(IV) tungstophosphate (TC-ZWP) has been used as a chelating agent for determination of rare earth metal ion i.e Nd(III). The poly(vinyl-chloride)-based membrane electrode exhibits a Nertian response for Nd(III) ions over a wide  concentration range   (1x 10 -1 to 5x 10 -5 M) with detection limit of  5x 10 -5 M. It has 25 s response time and can be used upto 45 days without any divergence in its potentials. The proposed membrane sensor reveals good selectivity for Nd(III) ions within the pH range of 3-7. Analytical application of electrode has been investigated for the quantitative determination of Nd(III) in sibaiya phosphate ores. It has been also successfully used as an indicator electrode in the potentiometric titration of Nd(III)  against standard  EDTA solution.

 

IPC Code: C08 J 5/22

Keywords: PVC membrane electrode, zirconium tunustophosphate, membrane sensor, neodymium(III) determination

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 504-508

 

High performance liquid chromatographic determination of astemizole in pharmaceutical dosage forms

K Basavaiah*, V S Charan  &  U  Chandrashekar 

 

A rapid, highly sensitive high performance liquid chromatographic method has been developed for the determination of astemizole that is suitable for routine use in quality control.  The chromatographic conditions comprised of a reversed-phase C18 column (250 x 4.6 mm) with a mobile phase of acetonitrile - 0.1% orthophosphoric acid,  pH adjusted to 3.9 (80:20 v/v).  The flow rate was 1.5 mL min-1 and uv detection was set at 215 nm.  The calibration graph  was linear from 5.13 - 405.0 mg mL-1.  The method was validated according to ICH guidelines including the assay of commercially available tablets.  Recoveries ranged from  98.10 to 101.90 %.  The utility and accuracy of the method were further established by parallel determination by a reference method and by recovery studies.  The excipients present in the tablets did not interfere.

 

IPC Code: B01 D 15/00, A61K

Keywords: Astemizole determination, HPLC, dosage forms

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 509-511

 

Voltammetric studies of endosulphan

Sunita Kumbhat* & Sushma Dave

 

The cyclic voltammogram of endosulphan recorded in various supporting electrolyte in aqueous methanolic medium at hanging mercury drop electrode, revealed a single cathodic peak at -1.25 V versus Ag/AgCl . The electrochemical behaviour of endosulphan after nitration at micro level has  been studied at glassy carbon electrode. The nitro derivative   also revealed a sharp cathodic signal at -0.9 V versus Ag/AgCl.  The electrode reaction is found to be irreversible and diffusion controlled. Cathodic peak appeared to be analytically useful.

 

IPC Code: A01 N 31/00, C01 N 27/00

Keywords: Cyclic voltammograph, endosulphan, glassy carbon electrode

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 512-517

 

Destabilization characteristics of talc in distilled and fresh waters

A Ozkan

 

The destabilization characteristics of talc were investigated in distilled and fresh water containing Ca2+, Mg2+, Na+ and Kions. The stability of the talc suspension remained almost constant in distilled water at all pH values, while it sharply decreased with these cations (i.e. in fresh water) at pH values above 10.5. In addition, the effects of A-95 (anionic), C-521 (cationic) and N-100 (non-ionic) flocculants on the destabilization of the suspension were also investigated in distilled and fresh waters. In fresh water, anionic and non-ionic flocculants were very effective on the talc suspensions at pH 7.2 and at pH values greater than 10.5. The stability of talc suspension was decreased by flocculation and also coagulation effect at pH levels greater than 10.5. The cationic flocculant caused weak destabilization of the suspension with distilled water in acidic conditions. However, this polymer was ineffective on the talc suspensions in fresh water at almost all pH levels.

 

IPC Code: C08 J 3/00, C01 F 5/00

Keywords: Talc, destabilization, stability, cations, polymeric flocculants, magnesium silicate

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 518-525

 

Removal of arsenic from water by different adsorbents

Rajeev Goel, S K Kapoor , Kshipra Misra* & R K Sharma

 

Present  study is  carried out  for the removal  of As( III)   from water using   commonly  available   adsorbents  such as   sand, from Yamuna river ( Delhi ), as well as from  Ganga river  (Kolkata ), activated carbon, Hametite ore and sand - iron scrap mixture. All these adsorbents are used as received but sand and activated carbon which do  not show much adsorption for As(III) are modified  by treating  with  different metal ions  in order to improve their  adsorption efficiency. Results of the laboratory experiments under static conditions  have confirmed that iron impregnated granular activated carbon (GAC), spherical activated carbon (SAC) as  well as sand - iron scrap mixture  have much promise as a medium  for the removal of As(III)  in drinking water. Various parameters like  adsorbent dose,  contact time, pH and arsenic  concentration  are optimized.  A simple and economical domestic arsenic removal  kit has been designed and successfully evaluated in the laboratory using sand-iron scrap mixture as media for the removal of arsenic from water.

 

IPC Code: C02 F 1/28

Keywords: Arsenic removal, hametite ore, activated carbon, sand, adsorption, drinking water        

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 526-530

 

Excess volumes of binary liquid mixture containing methyl butyrate with bromobenzene,
chlorobenzene and nitrobenzene at 303K, 308K and 313K

M V Rathnam* & R K Singh

 

Excess volumes for the binary liquid mixtures of methyl butyrate with bromobenzene, chlorobenzene and nitrobenzene have been calculated from the density data at 303K, 308K and 313K as a function of composition. Values of excess volumes (VE) for all the systems studied are found to be highly negative over the entire range of composition. The negative values of VE were found to increase with increase in temperature.

 

IPC Code: G01 N 9/00

Keywords: Binary liquid mixture, methyl butyrate, halogenated hydrocarbon, excess volume

               

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 531-534

 

Comparison of SFE, ASE, and soxhlet extraction procedures for the determination of polycyclic aromatic hydrocarbons associated with airborne particulate matter

S M Talebi* & A Taebi

 

The efficiencies of three different extraction procedures including supercritical fluid extraction, accelerated solvent extraction, and soxhlet for extraction of polycyclic aromatic hydrocarbons from airborne particulate matter were investigated. Although the results obtained from the three methods and especially ASE and SFE were very close to each other, SFE was found as the most effective methods for extraction of PAHs from airborne particulate matter. The effect of temperature on the efficiency of extraction of PAHs by SFE was also investigated and showed that the extraction efficiency can be improved by performing the extraction at higher temperatures.    

 

IPC Code: C07 C 15/00, B01 D 11/00

Keywords: Polycyclic aromatic hydrocarbon, SFE, ASE, airborne particulate matter

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 535-547

 

Simulation of electro-mixer-settler for the partitioning of uranium and plutonium in PUREX process

 N K Pandey* & S B Koganti

  

The mathematical basis for a computer code PUSEP (Plutonium Uranium Solvent Extraction Program) for the analysis of partitioning cycle of PUREX process involving in-situ electrochemical reduction of uranium and plutonium is described in the present investigation. The basis of development of model equations involves countercurrent multi-component extraction coupled with chemical and electrochemical reactions. The model is specific to mixer-settler contactors and is restricted to mass transfer equilibrium. The components considered in the model equations are U(VI), U(IV), Pu(IV), Pu(III), nitric acid and hydrazine. Computer code provides transient behaviour of mixer-settler contactor from the start-up conditions to the steady-state conditions. The code has been validated with the experimental data available in literature. The calculated results are consistent with the experimental results considering the major components mentioned above.

 

IPC Code: B01 D 59/38, G06 F 17/00

Keywords: PUREX process, uranium, plutonium, partitioning, simulation

           

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 548-554

 

Transport of Pu(IV) across supported liquid membrane from nitric acid medium using
cyanex- 923 as the mobile receptor

S R Sawant, J V  Sonawane, Anil Kumar Pabby*, A K Venugopalan , P K  Dey &  B Venkataramani

 

Based on the solvent extraction data, experiments were conducted with Flat-sheet Supported Liquid Membrane (FSSLM) to examine the transport behaviour of Pu(IV) to achieve its maximum recovery. This is necessary to optimize the conditions for further operation of  Hollow Fiber Supported Liquid Membrane (HFSLM) and Compact Supported Liquid Membrane  Flow Cell (CSLMFC). A laboratory scale hollow fiber module, having membrane surface area, 134 cm2, was employed in a recycling mode using ‘Enka’ Accurel hollow fiber polypropylene membranes as the solid support, cyanex-923 as the mobile receptor and dodecane as the membrane solvent. Dilute plutonium nitrate solutions in 1M HNO3 generally  constituted the source phase. Among the strippants, several  reagents were tried, the most efficient strippant found was dilute uranous solution in 1.0M HNO3. The recovery of Pu from the Pu oxalate supernatant generated during Pu reconversion operations in  the PUREX process was tried, where it was observed that ~ 94 % of Pu(IV)  could be transported in a single run of duration of 10 h,  while employing 0.1M cyanex-923/dodecane  as a mobile receptor and  uranous solution in   1.0 M HNO3 as the strippant. Parameters such as source phase concentration, source and strippant phase recirculation flow rate, concentration of carrier in the membrane and strippant, and interferences of other permeants on plutonium permeation pertaining to FSSLM, HFSLM and CSLMFC were optimized.

 

This followed the utilization of more application oriented configuration i.e. Hollow fiber membrane configuration for the above purpose. 

 

With HFSLM, the  Kobs  values increased from 3.06 x10-5 to 6.27 x10-5  s-1   by   increasing   flow rate from  0.03 x10-6  to 0.14x 10 -6  m3/s  at 1 h and the percentage permeation increased from 75 to 90%.  In  the case  of  CFSLMC, the Kobs increased from 5.41 x10-5 to 5.74 x10-5 s-1 while increasing flow rate from 0.27 x10-6  to 0.42 x10-6  m3/s , at 1h and the percentage permeation  increased from   65 to  85% .

 

IPC Code: C22 B 60/04

Keywords: Pv(IV) transport, FSSLM, mobile receptor, cynex 923, dodecene, HFSLM, CSLMFC

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 555-559

 

Sequestration and remediation of heavy metals by Brassica sp at  Hindan river sites

 Anwar Ahmad* & Masood Alam

 

Various kinds of industries have grown up in and around city Ghaziabad (Sahibabad industrial area). The river Hindan is the principal sink of industrial effluents and agricultural wastewater. Industries discharge effluents directly into the river Hindan. The pollution is widespread but varies in its intensity and toxicity from place to place. The analyses and monitoring of some plants grown with water contaminated with industry effluent revealed the accumulation pattern of various heavy metals like Hg2+, Cd2+, Pb2+, Ni2+ and Zn2+ in different plants. Among the plants tested only Brassica juncea has potential to withstand contaminated river samples as it has means to sequester toxic metals in specific compartments.

 

IPC Code: (C02 F 3/32, 101:20)

Keywords: Brassica juncea, sequestration, remediation, heavy metals

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 560-564

 

Design and fabrication of a catalytic reactor for treating automobile exhaust

J Soji Adeyinka*, J U Okoli & Yousuo Digineni

 

A reactor was designed for the conversion of exhaust pollutants from an internal combustion engine using gasoline as fuel.  A bed height of 420 mm was used with an internal diameter of 40 mm; a space-time of 23.6s and a fractional conversion of 0.99 at a space velocity of 0.042 m/s was achieved.  A catalyst formulation of PtO2  (1%), Devarda alloy (Al, 45; Cu, 50 and Zn 5%) with NH4VO3 and g-Al2O5 support was prepared to meet the reaction specification of particle length 0.28 + 2mm, and diameter of 0.15mm.  Performance evaluation of the pollutant conversion at 375°C + 25°C showed 98% conversion of CO, 99% of HC and NOx 98% with 100% hydrogen utilisation.

 

IPC Code: B01 D 53/34

Keywords: Devarda, exhaust converter, pollutants, void volume, catalytic reactor, IC engine, automobile exhaust

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 565-568

 

A facile synthesis of fatty acid esters of para-cresol catalysed by acid activated Indian bentonite

B Vijayakumar, Pushpa Iyengar, Gopalpur Nagendrappa  & B S Jai Prakash *

 

p-Tolyl esters of some long chain fatty acids having commercial applications are synthesized using acid activated Indian bentonite as catalyst. Experimental conditions have been optimised to get the best yields. The effects of the molar ratio and reaction time have been investigated. The rate constant (k), the equilibrium constant (K) and the standard Gibbs free energy (DGo) are calculated. The spent catalyst on regeneration [by washing and heating to 110ºC] shows the same activity, and is found to be reusable several times.

 

IPC Code: C07 C 67/00, C07 C 39/07, B01 J 21/00

Keywords: Acid activated Indian betonite, easterification, p-tolyl esters, regeneration, catalysis

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 569-574

 

Oxidative coupling of methane over La-promoted MgO catalysts: Influence of precursors and method of
catalyst preparation

V R Choudhary*, V H Rane & S T Chaudhari

 

The influence of precursors for La2O3 (viz. lanthanum acetate and  lanthanum nitrate) and MgO (viz. magnesium acetate, magnesium carbonate and magnesium hydroxide) and catalyst preparation methods (viz. physical mixing of the catalyst precursors and coprecipitation using different precipitating agents such as ammonium hydroxide, ammonium carbonate and sodium carbonate) of La-promoted MgO (La/Mg = 0.1) catalyst on its surface area, total and strong basicity (measured in terms of CO2 chemisorbed at 50 and 500oC, respectively) and catalytic performance in oxidative coupling of methane (OCM) to C2-hydrocarbons at different temperatures  (750-850oC), CH4/O2 ratios  (4.0 and 8.0) for a high  space velocity  (51,360  cm3.g-1.h-1) has been investigated. The catalyst prepared using the coprecipitation method have higher surface area and basicity (total and strong basic sites measured in terms of CO2 chemisorbed at 50 and 500oC, respectively) but lower activity/selectivity, whereas, the catalyst prepared using the physical mixing method have lower surface area and basicity (both total and strong basic sites) but show higher activity and selectivity in the OCM process, depending upon the La- and Mg- salts used as the catalyst precursors. The catalyst, prepared by physical mixing using lanthanum nitrate and magnesium carbonate (prepared by precipitation from magnesium nitrate and sodium carbonate) as the catalyst precursors showed best catalytic performance in the OCM at different process conditions.

 

IPC Code: B01 J 21/00

Keywords: Oxidative coupling, methane,La-promoted MgO catalysts, catalytic selectivity

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, July 2004, pp 575-581

 

Crystallization of HMX in acetone-water system

Souraseni Basu, N M Gawande, M E Apte & V L Narasimhan*

 

Cyclotetramethylene-tetranitramine (HMX) is prepared by continuous nitrolysis of hexamine using nitric acid and ammonium nitrate in the presence of acetic anhydride and acetic acid. HMX obtained after nitrolysis contains RDX and some nitro compounds as impurities. It is purified by evaporative crystallisation technique using acetone as the solvent. In this work a ternary system consisting of HMX as the solute, acetone as solvent and water as anti-solvent was studied in order to obtain solubility data and  influence of different parameters viz. percentage recovery of solvent, stirrer speed, cooling rate, and  rate of recovery of solvent on the crystal size distribution (CSD) of HMX. The crystal morphology was also studied by using scanning electron microscope (SEM). The CSD of HMX obtained by using acetone-water mixture is compared with the CSD obtained by using acetone as solvent. It has been observed that under similar conditions of crystallisation, crystals obtained from acetone-water mixture are smaller than those obtained from acetone. Also, the crystals obtained from acetone-water system are more regular in shape and have smooth surfaces.

 

IPC Code: B01 D 9/02

Keywords: HMX, crystallization, acetone-water system, crystal size distribution

 

 

 

Indian Journal of Chemical Technology

Vol. 11, July 2004, pp 582-592

 

The nature of heat

 Jaime Wisniak

 

 The nature and effects of heat have intrigued philosophers and scientists since ancient times. Different theories were developed to explain the phenomena, and of these, the wave theory and the caloric theory were the ones that remained in force until the second half of the nineteenth century when overwhelming evidence led to the conclusion that heat was not a material substance, that the molecules of a gas were not stationary but could move in space, and that radiation and light were basically the same phenomena.

 

Keywords: Heat, wave theory, materi ignis, undulatory theory