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Indian Journal of Chemical Technology

 

 

 

ISSN:0971-457X

 

CODEN:ICHTEU 11(3) 293-450

VOLUME 11

NUMBER 3    

MAY 2004

 

 

CONTENTS

 

Research Articles

 

 

 

Removal of fluoride ion from aqueous bodies by aluminium complexed amino phosphonic acid type resins

299

IPC Code: (C02F 1/28, 101:14)

 

Dharmesh B Bhatt, Prashant R Bhatt, H Hari Prasad, Kirit M  Popat & Pritpal Singh Anand

 

 

An efficient and reversible sorptive removal of arsenic(III) from aqueous solution by the biosorbent Cupressus Female Cone   

 304

IPC Code: (C02F 1/28, 101:10)

 

M Murugan & E Subramanian

 

 

 

Use of bromophenol blue in the spectrophotometric and turbidimetric determination of  mebrophenhydramine in tablets

309

IPC Code: G01J 3/00, A61K 31/13

 

K Basavaiah & V S Charan

 

 

 

Studies on the chemistry of thermal drying of lignite in inert atmosphere   

314

IPC Code: E 21C 41/18

 

Joy Mukherjee, Ms Puspa Singh & Abhijit Sarkar

 

 

 

Molybdenum complexes as precursors of tribologically active substances under extreme pressure conditions

  317

IPC Code: C01G 39/00

 

R B Rastogi & M Yadav

 

 

 

Determination of alcohol in petrol-alcohol mixtures                              

323

IPC Code: G01N 9/36

 

G S R Sastry, P Ravi Prasad & K Bhuvaneswari

 

 

 

Preparation and characterization of molybdenum hydrotreating catalyst supported on MgO/Al2O3  mixed oxide

326

IPC Code: B01J 23/28

 

Folorunsho Aberuagba,  Manoj Kumar, Gudimella Muralidhar &  Lakshmi Datt Sharma

 

 

 

 

Inhibition of mild steel corrosion in formic and acetic acid solution  

331

IPC Code: C23F 11/04

 

M A Quraishi & H K Sharma

 

 

 

 

Alkylation of benzene with ethanol over ZSM-5 catalyst with different SiO2/Al2O3 ratios          

337

IPC Code: C07B 37/00

 

Jun-Jun Yuan & Börje S Gevert

 

 

Corrosion inhibition by caffeine ¾ Mn2+ system

 

346

IPC Code: C23F 11/00

 

Noreen Anthony, E Malarvizhi, P Maheshwari, Susai Rajendran & N Palaniswamy

 

 

Alkylation of naphthalene with t-butanol over zeolite Y: Influence of reaction environment and reaction kinetics

351

IPC Code: C07B 37/00

 

R Nagotkar, S S Khaire, S Mayadevi & S Sivasanker

 

 

 

Studies of printing inks on starch blended and surface grafted polyethylene film for flexible packaging         

357

IPC Code: C09D 11/02

 

R N Ghosh, B Adhikari & B C Ray

 

 

 A population balance model for  miniemulsion polymerization

 367

IPC Code: C08F 2/22

 

A Sood  & S K Awasthi

 

 

 

 

Influence of microwave irradiation on enzymatic activity of invertase in aqueous and organic solvents

377

IPC Code: C12N 9/26, B01J 19/08

 

C N Khobragade & Ganesh V Kore

 

 

 

 

Effect of flotation reagents on the wet grinding of celestite concentrate   

382

IPC Code: B22F 9/00, B03D 1/001

 

Yakup Cebeci & Oktay Bayat

 

 

 

 

Effect of magnetic field on membrane potential                                      

388

IPC Code: G01N 13/00

 

Meena Sharma & R L Blokhra

 

 

 

 

Liquid drainage in static foam:  Analogy with liquid drainage through packed bed                  

392

IPC Code: B01D 19/02, B01J 19/10

 

Pankaj V Ambulgekar, Anjali C Dedhia & Aniruddha B Pandit

 

 

 

 

Vapour phase transesterification over solid acids for the synthesis of isoamyl salicylate          

401

IPC Code: C07B 41/12

 

Joyce D’Souza & N Nagaraju

 

 

 

 

Low temperature oxidation of ethanol                                                 

410

IPC Code: C07B 33/00

 

S S Verma

 

 

 

Photocatalytic bleaching of amaranth dye over ZnO powder                 

423

IPC Code: C09B 61/00, G01j 1/00

 

Rameshwar Ameta, Nilesh Jain & Sharad Kothari

 

 

CO oxidation over Pd/g-FeMnO3 catalyst

 

427

IPC Code: C01B 31/18, B01J 23/54

 

S K Kulshreshtha, S Sharma, R Vijayalakshmi & R Sasikala

 

 

 

Educator

 

 The nature and composition of water

434

Jaime Wisniak                                                 

 

 

Chem-Tech Scan                                                       

445

   
Author Index      

449

                                                                            

 Keywords Index

450

 

 

Indian Journal of Chemical Technology

Vol. 11, May 2004, pp 299-303

 

Removal of fluoride ion from aqueous bodies
by aluminium complexed amino phosphonic acid
type resins

Dharmesh B Bhatt, Prashant R Bhatt, H Hari Prasad, Kirit M Popat & Pritpal Singh Anand*.

 

Three resins, namely Purolite S940, Purolite S950 and Duolite ES 467 were studied for the removal of fluoride ion under different equilibrium conditions. The adsorption data of Purolite S940 and Purolite S950 closely fitted in Freundlich and Langmuir equations, respectively. Validity of the Lagergan equation for the sorption of fluoride ion was proved and the data showed that the process followed first order kinetics. The performance of Purolite S940 and Purolite S950 showed good promise for removing fluoride from water whereas the performance of Duolite ES467 was comparatively poor under dynamic conditions.

 

IPC Code: (C02F 1/28, 101:14)

Keywords: Fluoride removal, Purolite S940, Purolite S950, Duolite ES467, resin, Freundlich equation, Langmuir equation, Lagergan equation

 

 

 

Indian Journal of Chemical Technology

Vol. 11, May 2004, pp 304-308

 

An efficient and reversible sorptive removal of
arsenic (III) from aqueous solution
by the biosorbent Cupressus Female Cone

M Murugan & E Subramanian*

 

Biosorbent Cupressus Female Cone (CFC) has been investigated for the sorptive removal of As(III) from aqueous solution both by batch and column mode techniques. Sorption process was found to be influenced appreciably by pH, temperature, initial concentration of As(III) and sorbent particle size and dosage. Also the sorption process was endothermic with a maximum sorption of 260.4 mg/g of As(III) at 30oC for an initial concentration of 800 mg/L at pH 10.0. It followed first order kinetics and the equilibrium sorption capacity data conformed to Langmuir isotherm. The pore diffusion and mass transfer coefficients of As(III) species were significant and contributive to the sorption rate. All these studies and characterisation of free and As(III)–loaded CFC materials by SEM, FTIR and XRD methods led to the suggestion of a plausible mechanism involving complex formation  between the two components. The As(III)-CFC  sorption system was further investigated by dynamic column study invoking Thomas model. Finally, the desorption studies revealed that the adsorbent CFC could be effectively regenerated by 0.1 M hydrochloric acid, making it a viable and reusable system for As(III) removal.

 

IPC Code: (C02F 1/28, 101:10)

Keywords: Sorptive removal; arsenic(III), biosorbent, cupressus female cone

 

 

 

Indian Journal of Chemical Technology

Vol. 11, May 2004, pp 309-313

 

Use of bromophenol blue in the spectrophotometric
and turbidimetric determination of
mebrophenhydramine in tablets

K Basavaiah* & V S Charan

 

Simple, sensitive, rapid and cost-effective methods are described for the determination of mebrophenhydramine hydrochloride (MPH) in pure form and in tablets using Bromophenol Blue (BPB) as a reagent. The spectrophotometric method is based on the formation of an ion-association complex of the drug with BPB in phthalate buffer of pH 3.0, its extraction into chloroform and absorbance measurement at 420 nm. In turbidimetry BPB was used to produce stable turbidity arising from the formation of drug-dye complex of very low solubility at an altered pH condition and reagent-concentration and in the presence of potassium chloride. The absorbance of the turbid suspension was measured at 650 nm. Various parameters affecting the analytical procedures were investigated and optimised. In spectrophotometry, Beer's law is obeyed over the concentration range of 2-12 mg mL-1 with an apparent molar absorptivity of 1.98´104 L moL-1 cm-1 and Sandell sensitivity of 19.39 ng cm-2. Turbidimetry is applicable in the concentration range of 10-70 mg mL-1. The limits of detection are 0.10 and 0.44 mg mL-1 for spectrophotometry and turbidimetry, respectively. The methods were used to determine MPH in standard solution with a coefficient of variation of less than 2%, and were further applied to the determination of MPH in tablets. The results obtained by the proposed methods agree with the label claim. The reliability of the methods was further established by recovery studies applying standard-addition technique.

 

IPC Code: G01J 3/00, A61K 31/13

Keywords: Mebrophenhydramine determination, spectrophotometric, turbidimetric

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 314-316

 

Studies on the chemistry of thermal drying of
lignite in inert atmosphere

Joy Mukherjee, Ms Puspa Singh & Abhijit Sarkar*

 

Drying of lignite and its storage for sufficient length of time in dried conditions has been an integral part of industrial economy, yet a fundamental understanding of the physico-chemical changes involved still lags far behind the practical use. Moisture is generally held in lignite by surface forces and oxygenated groups. Elimination of carboxyl groups by thermal decarboxylation has been found to reduce moisture holding capacity of lignite. In this paper a relationship has been shown to exist between carboxyl-oxygen and moisture of lignite at 60 percent relative humidity (RH) condition. Thermal behaviour of carboxylic acid functionality has been studied. Dehydroxylation was not observed at optimum temperature of decarboxylation. The nature and disposition of carboxylic acid functionality in lignite has been indicated.

 

IPC Code: E21C 41/18

Keywords: Thermal drying, lignite, dehydroxylation

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 317-322

 

Molybdenum complexes as precursors of tribologically active substances under extreme pressure conditions

R B Rastogi* & M Yadav

 

Some molybdenum complexes of N-isonicotinyl-N’ aryl thiosemicarbazides were studied for their tribological activity using four ball test machine. All the compounds were found to be significantly effective extreme pressure lubrication additives. Their EPL efficiency has been compared on the basis of various tribological parameters like wear scar diameter, friction coefficient, initial seizure load (ISL), 2.5s seizure delay load (2.5 s SDL), weld load (WL), mean Hertz load (MHL), pressure wear index (PWI) and flash temperature parameter (FTP). The topography of the wear scar surface of balls in presence of p-chlorophenyl derivative has been studied by scanning electron microscopy at 2.5s seizure delay load and just before weld load. Auger electron spectroscopy has been used to analyze the wear scar surface at just before weld load.

 

IPC Code: C01G 39/00

Keywords: Molybdenum complexes, aryl thiosemicarbazides, tribological activity, lubrication additives

 

 

 

Indian Journal of Chemical Technology

Vol. 11, May 2004, pp 323-325

 

Determination of alcohol in petrol-alcohol mixtures

G S R Sastry*, P Ravi Prasad & K Bhuvaneswari

 

A simple and rapid method for the determination of alcohol in petrol-alcohol mixtures using density measurements is described. The method can determine a minimum of 1% of alcohol by volume. The precision of the method is ± 3%. The method is more useful for field test in the quality assessment of alcohol blended petrol.

 

IPC Code: G01N 9/36

Keywords: Petrol-alcohol mixture, alcohol determination, density measurement

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 326-330

 

Preparation and characterization of molybdenum hydrotreating catalyst
supported on MgO/Al2O3 mixed oxide

Folorunsho Aberuagba*, Manoj Kumar, Gudimella Muralidhar & Lakshmi Datt Sharma

 

A series of molybdenum catalysts supported on MgO/Al2O3 (1:1) mixed oxide were prepared and characterized by BET surface area, X-ray diffraction, temperature programmed reduction and oxygen chemisorption. The catalytic activities for hydrodesulpurization(HDS), hydrogenation(HYD) and hydrocracking(HYC) were determined using thiophene, cyclohexene and cumene as model compounds respectively. Results indicate that at 2- 8% Mo loading, the catalyst is more dispersed and crystallite growth occurred beyond this range. The optimum metal loading for maximum oxygen uptake and catalytic activities for HDS, HYD and HYC was concluded to be 8%. The order of catalytic activity for HDS, HYD and HYC was: HYD>HYC>HDS. However, the Co promoted catalyst showed remarkable increase in both the HDS and HYD activity with no significant change in HYC activity, with the following order: HDS>HYD>HYC, the optimun Co loading being 3%.

 

IPC Code: B01J 23/28

Keywords: Hydrotreating, Mo catalyst, hydrosulpurization, hydrogenation, hydrocracking, Co catalyst

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 331-336

 

Inhibition of mild steel corrosion in formic and
acetic acid solutions

M A Quraishi*& H K Sharma

 

Four organic inhibitors namely, 4-amino-3-methyl-5-mercapto-1,2,4-triazole (AMMT), 4-amino-3-ethyl-5-mercapto-1,2,4-triazole (AEMT), 4-amino-3-propyl-5-mercapto-1,2,4-triazole (APMT) and 4-amino-3-butyl-5-mercapto-1,2,4-triazole (ABMT) were synthesized to investigate their inhibiting actions on corrosion of mild steel (MS) in aqueous solutions containing 20% formic acid and 20% acetic acid by weight loss and potentiodynamic polarization methods. All of these compounds have shown good inhibition efficiency (IE) in the formic acid and acetic acid solutions. IE of these compounds has been found to vary with the concentration of the compounds, temperature, immersion time and concentration of acid solutions. The adsorption of these compounds on the mild steel surface from both the acids has been found to obey Langmuir adsorption isotherm. The values of activation energy (Ea) and free energy of adsorption (DGads) indicated physical adsorption of these compounds on the steel surface. The potentiodynamic polarization experiments revealed that all the compounds are mixed type inhibitors.

 

IPC Code: C23F 11/04

Keywords: Corrosion inhibitor, mild steel, triazoles, acetic acid, formic acid.

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 337-345

 

Alkylation of benzene with ethanol over ZSM-5 catalyst with different SiO2/Al2O3 ratios

Jun-Jun Yuan & Börje S Gevert*

 

Alkylation of benzene with ethanol has been done in a laboratory scale reactor with ZSM-5 diluted with silica as a catalyst. The experiments have been done at the different reaction temperatures using different catalysts in the reactor to study the change of activity and selectivity of the desired product. The feed and products were analysed by gas chromatography. Alkylation of benzene with ethanol yielded ethylbenzene as the primary product and small amount of diethylbenzene isomers. For unmodified H-type of ZSM-5 catalyst, higher conversion of benzene and the selectivity for ethylbenzene go through a maximum between 400 and 450 ºC with a SiO2/Al2O3 ratio of around 100. The SiO2/Al2O3 ratios were varied between 34 and 331. Modified B- and Mg- types of ZSM-5 zeolites are also examined.

 

IPC Code: C07B 37/00

Keywords: Alkylation, benzene, ZSM-5, selectivity, SiO2/Al2O3 ratios, ethylbenzene

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 346-350

 

Corrosion inhibition by caffeine – Mn2+ system

Noreen Anthony, E Malarvizhi, P Maheshwari, Susai Rajendran* & N Palaniswamy

 

The inhibition efficiency of caffeine in controlling corrosion of carbon steel immersed in 60 ppm of Cl- ion environment has been evaluated, in the absence and presence of Mn2+ ions, by weight loss method. Influence of sodium dodecyl sulphate, pH and immersion period on the inhibition efficiency of the caffeine-Mn2+ ion system has also been investigated. The protective film formed on the metal surface has been analysed by FTIR spectra. The protective film consists of Fe2+ - caffeine complex and Mn(OH)2.

 

IPC Code: C23F 11/00

Keywords: Corrosion inhibition, caffeine-Mn2+ system, carbon steel, chloride ion environment, sodium dodecyl sulphate

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 351-356

 

Alkylation of naphthalene with t-butanol over
zeolite Y: Influence of reaction environment and reaction kinetics

R Nagotkar, S S Khaire, S Mayadevi* & S Sivasanker

 

The t-butylation of naphthalene with t-butanol over different Y-zeolites and at different environments is reported. The zeolites investigated are H-Y, RE-Y and three US-Y samples with different Si/Al ratios. Though, as expected, increasing the reaction temperature (160-180 ºC) increases naphthalene conversion, increasing the TBA/naphthalene mole ratio beyond 2 results in a decrease in conversion, presumably due to poisoning by the larger amount of water produced during dehydration. Both activity and yield of dialkylnaphthalenes increase on RE exchange and dealumination of H-Y. Higher conversions are obtained when the reaction is conducted under neat conditions than in the presence of the solvent cyclohexane or the added gas, N2.

 

IPC Code: C07B 37/00

Keywords: Alkylation, naphthalene, t-butanol, zeolite Y, reaction kinetics

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 357-366

 

Studies of printing inks on starch blended and surface grafted polyethylene film for flexible packaging

R N Ghosh, B Adhikari* & B C Ray

 

Grafted vinyl acetate surface of starch blended biodegradable polyethylene film was printed with industry standard printing inks based on polyamide resin and organic solvents. Various print and packaging properties were studied to find suitability of the use of such grafted polyethylene film in comparison to ungrafted starch blended polyethylene film and industry standard corona treated polyethylene film. The use of such grafted film was also comparatively studied in polyethylene laminate packaging. Prints and laminates using industrial standard grade polyethylene, starch blended biodegradable polyethylene and grafted starch blended polyethylene film, were put on soil burial test and studied for biodegradable properties.

 

IPC Code: C09D 11/02

Keywords: Printing ink, grafted polyethylene film, flexible packaging, biodegradable

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 367-376

 

A population balance model for miniemulsion polymerization

A Sood* & S K Awasthi

 

Miniemulsion polymerization is mechanistically distinct from the conventional emulsion polymerization in several aspects; the most important being that the nucleation occurs in the small and stable monomer droplets. This process is being used to produce polymer latexes of unusual characteristics. The initial droplet size distribution and the final particle size distribution in miniemulsion polymerization are broad. This has not been addressed by the present models, which are based on the grosser perspectives of this system and assume monodisperse droplet size and particle size distributions. A population balance model for the miniemulsion polymerization that incorporates the particle size distribution is developed in this work.  The model predictions are verified against data taken from the literature.

 

ICP Code: C08F 2/22

Keywords: Population balance model, miniemulsion, polymerization

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 377-381

 

Influence of microwave irradiation on enzymatic activity of invertase in aqueous and organic solvents

C N Khobragade* & Ganesh V Kore

 

Sucrose hydrolysis reaction, catalysed by invertase under microwave irradiation was carried out in aqueous, isopropanol + water and polyethylene glycol + water system. The effect of conventional and microwave heating on the rate of hydrolysis was studied under a range of physical exposure conditions. The catalytic activity of invertase in aqueous and organic solvents were measured at different temperatures. Enhanced reaction rate and yield in organic media was observed over aqueous media using microwave heating.

 

IPC Code: C12N 9/26, B01J 19/08

Keywords: Microwave irradiation, sucrose hydrolysis, invertase activity

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 382-387

 

Effect of flotation reagents on the wet grinding of celestite concantrate

Yakup Cebeci* & Oktay Bayat

 

In this study, the grinding of celestite concentrate in presence of grinding aids, used for celestite ore, flotation has been investigated in a laboratory wet-ball mill as a function of time and concentration of grinding aids. In the experiments, Aero-801, sodium oleate and sodium silicate have been used as grinding aids at the concentrations of 10, 100 and 1000 g/t.

 

While sodium oleate and sodium silicate have beneficial effect in longer grinding times at concentrations of 100 and 1000 g/t, they have adverse effect on grinding at all grinding times at concentration of 10 g/t as evident from particle size. d80 values of ground products are coarser than that without grinding aid. Aero-801 is the best among the grinding aids tested for the concentrations studied. Considering the fineness of the ground products desired, 100 g/t concentration of Aero-801 appears to be proper for grinding of celestite concentrate.

 

IPC Code: B22F 9/00, B03D 1/001

Keywords: Flotation, celestite, aero-801, sodium silicate, sodium oleate, grinding aid

 

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 388-391

 

Effect of magnetic field on membrane potential

Meena Sharma* & R L Blokhra

 

Transport has been studied from the point of view of irreversible thermodynamics for aqueous solutions of sodium chloride, potassium chloride and lithium chloride across a sintered disc impregnated with cellulose acetate under the influence of variable magnetic field. Teorell-Meyers-Siever theory has been used to evaluate the ionic transport numbers. The data has been interpreted for Permselectivity and Fixed Charge Density in all the electrolytes and comparisons have been discussed.

 

IPC Code: G01N 13/00

Keywords: Ionic transport, fixed charge density, NaCl, KCl, LiCl, permselectivity, magnetic field, membrane potential

 

 

 

 

Indian Journal of Chemical Technology

Vol. 11, May 2004, pp 392-400

 

Liquid drainage in static foam: Analogy with liquid drainage through packed bed

Pankaj V Ambulgekar, Anjali C Dedhia & Aniruddha B Pandit*

 

High intensity ultrasonic vibrations are known to be efficient at destabilizing stationary foams. In this paper, the effect of the application of ultrasonic vibrations generated by an ultrasonic bath has been studied on the drainage of static foam. The vibrations are found to enhance the drainage rate of the foam and the model could be extended to correlate these drainage rates. This model can also be used to predict the variation in the foam cell size and shape factor during drainage. The effect of type of sparger and column diameter on the drainage rate has been studied. The rate of foam collapse depends on the foam cell size, which in turn depends on the sparger used for foam generation. The foam drainage and collapse rates were found to increase with the decrease in the column diameter.

 

IPC Code: B01D 19/02, B01J 19/10

Keywords: Ultrasonic vibrations, static foam

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 401-409

 

Vapour phase transesterification over solid acids for the synthesis of isoamyl salicylate

Joyce D’Souza & N Nagaraju*

 

The transesterification of methyl salicylate with isoamyl alcohol has been studied in vapour phase over solid acid catalysts for the synthesis of isoamyl salicylate. The catalysts used include simple oxides ¾ Al2O3, SiO2, ZrO2 and mixed oxides ZrO2-Al2O3 and ZrO2-SiO2. The effect of sulphation on the catalytic activity of the oxides and mixed oxides has also been investigated for this reaction. Catalytic activity studies have been conducted at 200oC for two different flow rates, 5 and 10 mL/h to check the effect of the contact time of the reactants with the catalyst. All the catalysts used in the reaction have been found to be active for the formation of isoamyl salicylate via transesterification of methyl salicylate with isoamyl alcohol. SO42/ZrO2-SiO2 (2:8) has been found to be the most active catalyst with 63% conversion of methyl salicylate to isoamyl salicylate. SO42-/ZrO2, which exhibited good selectivity was chosen as the catalyst for optimisation of the reaction conditions to obtain better yield and higher selectivity of isoamyl salicylate. Optimum yield of isoamyl salicylate was obtained with the following reaction conditions: amount of catalyst = 0.5 g, calcination temperature = 550oC, reaction temperature = 200 oC, preheater temperature = 250 oC, molar ratio of methyl salicylate to isoamyl alcohol = 1:1.

 

IPC Code: C07B 41/2

Keywords: Transesterification, solid acid catalysts, methyl salicylate, isoamyl alcohol

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 410-422

 

Low temperature oxidation of ethanol

S S Verma

 

Oxidation characteristics of ethanol in the temperature range 200 to 1000 oC suitable to its use in automobiles are studied to highlight the role and optimum values of different combustion controlling parameters for its clean combustion. Sensitivity evaluation of different reaction paths has concluded some important reactions responsible for the ethanol oxidation. It is observed that clean combustion of ethanol can be obtained with a proper combination of combustion parameters viz., temperature, C2H5OH/O2 mole ratio and residence time.

 

IPC Code: C07B 33/00

Keywords: Ethanol, oxidation, high-octane fuel

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 423-426

 

Photocatalytic bleaching of amaranth dye
over ZnO powder

Rameshwar Ameta*, Nilesh Jain & Sharad Kothari

 

 

The photocatalytic bleaching of amaranth over zinc oxide powder was observed spectrophotometrically. The effects of the concentration of amaranth, pH, amount of semiconductor, light intensity on the rate of the photocatalytic bleaching were also studied. A tentative mechanism for the photocatalytic bleaching of amaranth is proposed.

 

IPC Code: C09B 61/00, G01J/00

Keywords: Amaranth dye, photocatalylic bleaching, ZnO powder, mechanism

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 427-433

 

CO oxidation over Pd/g-FeMnO3 catalyst

S K Kulshreshtha*, S Sharma, R Vijayalakshmi & R Sasikala

 

g-FeMnO3 samples with and without Pd metal impregnation have been prepared by co-precipitation method and investigated by powder X-ray diffraction and 57Fe Mossbauer spectroscopy techniques, for its bulk characteristics. Catalytic activity of these samples has been studied for CO oxidation reaction by injecting CO or (CO+O2) pulses over their surface, with a view to delineate the role of Pd metal and reducible cations during this reaction. Pd metal impregnation over the surface of g-FeMnO3, leads to significant improvement in its catalytic activity, particularly at lower temperatures. Based on these experiments, clear evidence for the low temperature (T~350 K) disproportionation of CO over the surface of Pd metal particles and lattice oxygen incorporation during CO oxidation reaction, have been presented. From the comparative study of Fe2O3, Mn2O3 and FeMnO3, the existence of any synergistic effects between Fe3+ and Mn3+ cations, is ruled out for FeMnO3, mixed oxide system.

 

IPC Code: C01B 31/18, B01J 23/54

Keywords: CO oxidation, Pd/g-FeMnO3 catalyst, metal impregnation

 

 

 

 

Indian Journal of Chemical Technology

 Vol. 11, May 2004, pp 434-444

 

The nature and composition of water

Jaime Wisniak

 

The nature and composition of water has intrigued scientists since the beginning of philosophical and scientific inquiries. From being a religious symbol and one of the primeval elements it had to wait until the end of the eighteenth century to elucidate that water was a compound material.

 

Keywords: Water, Cavendish, Lavoisier, Dumas, Morley