Faculty Publications
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Item MoVW-mixed oxide as a partial oxidation catalyst for methanol to formaldehyde(Elsevier Inc., 2006) Badekai Ramachandra, B.R.; Jung, S.C.; Kim, K.-S.; Choo, K.-Y.; Sung, J.-S.; Kim, T.-H.Mixed oxide with composition Mo0.65V0.25W 0.10Ox was synthesized and its catalytic activity for the selective oxidation of methanol to formaldehyde was investigated. The characterization by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray and Fourier transform infra-red spectroscopy reveals that the prepared catalyst is inhomogeneous nanocrystalline Mo5O 14-type oxide with minor amount of MoO3-type and MoO 2-type material. Thermal activation treatment of the catalyst at 813K resulted in better crystalline sample. The overall structural analysis suggests that the catalytic performance of the MoVW-mixed oxide catalyst in partial oxidation of methanol is related to the formation of the Mo5O 14-type material. © 2006 Elsevier B.V. All rights reserved.Item Methanol selective oxidation to formaldehyde over a modified Fe-Mo catalyst with two different stoichiometric (Mo/Fe atomic ratio = 1.5 and 3.0) was studied experimentally in a fixed bed reactor over a wide range of reaction conditions. The physicochemical characterization of the prepared catalysts provides evidence that Fe2(MoO4)3 is in fact the active phase of the catalyst. The experimental results of conversion of methanol and selectivity towards formaldehyde for various residence times were studied. The results showed that as the residence time increases the yield of formaldehyde decreases. Selectivity of formaldehyde decreases with increase in residence time. This result is attributable to subsequent oxidation of formaldehyde to carbon monoxide due to longer residence time.(Selective oxidation of methanol to formaldehyde using modified iron-molybdate catalysts) Kim, T.-H.; Badekai Ramachandra, B.; Choi, J.-S.; Saidutta, M.B.; Choo, K.-Y.; Song, S.-D.; Rhee, Y.-W.2004Item Molybdenum based mixed oxide containing Mo0.65V 0.25W0.10 was investigated for the partial oxidation of methanol. The structural property and catalytic activity of the mixed oxide catalyst was studied by surface area (BET), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The thermal activation of the catalyst resulted increase in the conversion of methanol and the selectivity to formaldehyde. The thermal activation of the MoVW mixed oxide in nitrogen atmospheres induces partial crystallization of a Mo5O14-type oxide at 813 K. The SEM images of the thermally activated catalyst show needle like particles. These particles were agglomerates of platelet-like crystallites of a few hundreds of nanometers in size. SEM and EDX techniques show that the mixed oxide is characterized by an inhomogeneous elemental distribution on the length scale of a few microns. XRD of the thermally activated catalyst showed a nanocrystalline material identified as a mixture of Mo5O 14, MoO3 and MoO2-type MoVW oxides. The catalytic activity of the MoVW mixed oxide show a good conversion of methanol and selectivity to formaldehyde. © 2005 Springer Science+Business Media, Inc.(Partial oxidation of methanol to formaldehyde on molybdenum based mixed oxide catalyst) Badekai Ramachandra, B.; Choi, J.-S.; Choo, K.-Y.; Sung, J.-S.; Song, S.-D.; Kim, T.-H.2005Item Synthesis and characterization of nanocrystalline Mo-V-W-Fe-O mixed oxide catalyst and its performance in selective methanol oxidation(2007) Badekai Ramachandra, B.; Choi, J.-S.; Kim, T.-H.A mixed oxide catalyst containing Mo, V, W and Fe with the composition of 63, 23, 09 and 06 wt% respectively for the selective oxidation of the methanol to formaldehyde is in reported in this paper for the first time. The characterization of the catalyst was done using BET surface analysis, X-ray diffraction (XRD), Infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy dispersive X-ray (EDX). The mixed oxide after calcination at 673 K in N2 which was subjected for the thermal activation in N 2flow at 813 K was used for the methanol selective oxidation. The thermal treatment shows enhanced catalytic performance. Thermal activation of the nanocrystalline Mo0.63V23W0.09Fe 0.06O x precursor oxide in nitrogen atmospheres induces partial crystallization of a Mo5O14-type oxide only in a narrow temperature range up to 813 K. XRD showed that the thermally activated mixed oxide consists of a mixture of a majority of crystalline Mo 5O14-type oxide and of small amounts of crystalline MoO3-type and MoO2-type oxides. The structural analysis suggests that the improvement of the catalytic performance of the MoVWFe oxide catalyst in the selective oxidation of methanol is related to the formation of the catalytic active site such as Mo5O14-type mixed oxide. © 2007 Springer Science+Business Media, LLC.Item Synthesis of biodiesel from edible and non-edible oils and characterisation(2009) Kapilan, N.; Ashok Babu, T.P.A.; Varun, J.D.In recent years, biodiesel has been receiving increasing attention because of scarcity and increasing cost of fossil fuels and growing emissions of combustion related pollutants. In the present work, biodiesel was synthesised via the transesterification of edible and non-edible oils such as gingili and mahua, with methanol as alcohol and sodium hydroxide as catalyst. The yield percentage obtained from non-edible mahua oil was comparable to that obtained from edible gingili oil, under optimum conditions. According to American Society of Testing and Methods (ASTM), several tests were conducted to characterise the biodiesel in relation to diesel oil, in order to evaluate various physical, chemical and thermal properties such as viscosity, acid value, iodine value, flash point, fire point and calorific value. From the results, it was observed that the fuel properties of biodiesel produced from mahua oil and gingili oil were within the recommended standards of biodiesel fuel of various countries. Hence the biodiesel produced from gingili oil and mahua oil can be used as a renewable alternative fuel for the diesel engine. © 2009 Energy Institute.Item Characterization and effect of using Mahua oil biodiesel as fuel in compression ignition engine(2009) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of Mahua Oil (MO) as one of the main alternative fuels to diesel. In this investigation, Mahua Oil Biodiesel (MOB) and its blend with diesel were used as fuel in a single cylinder, direct injection and compression ignition engine. The MOB was prepared from MO by transesterification using methanol and potassium hydroxide. The fuel properties of MOB are close to the diesel and confirm to the ASTM standards. From the engine test analysis, it was observed that the MOB, B5 and B20 blend results in lower CO, HC and smoke emissions as compared to diesel. But the B5 and B20 blends results in higher efficiency as compared to MOB. Hence MOB or blends of MOB and diesel (B5 or B20) can be used as a substitute for diesel in diesel engines used in transportation as well as in the agriculture sector. © 2009 Science Press, Institute of Engineering Thermophysics, CAS and Springer Berlin Heidelberg.Item Microwave-assisted batch synthesis of Pongamia biodiesel(2010) Venkatesh Kamath, H.; Iyyaswami, I.; Saidutta, M.B.Background: The major bottleneck of biodiesel synthesis is its cost and this is mainly attributed to the feedstock material. Pongamia pinnata oil is a nonedible oil that is available in plenty in India and has negligible applications. Several methods of synthesis have been established, each having their own advantages and disadvantages. Results & discussion: Biodiesel from high-free fatty acid, nonedible, Pongamia oil was synthesized under microwave irradiation with single- and two-step methods. Experimental investigations showed that although the single-step method had a high yield (80%), the acid value of biodiesel was quite high. Hence, the two-step method seems to be a better approach as it yielded 90%, with 1:10 oil:methanol molar ratio and 1 wt% KOH. Along with a decrease in the reaction time to 4-5 min, separation time was also decreased by at least 90%. A conventional heating method was employed to compare the effects of microwave irradiation on biodiesel synthesis. Conclusion: The results indicate significant improvement in the yield, reaction time and processing time of biodiesel under microwave irradiation. The synthesis of Pongamia biodiesel under microwave irradiation could perhaps lead to cost effective and faster technology in countries such as India. © 2010 Future Science Ltd.Item Optimization of two step karanja biodiesel synthesis under microwave irradiation(2011) Venkatesh Kamath, H.; Iyyaswami, I.; Saidutta, M.B.The free fatty acid of crude karanja oil (Pongamia pinnata) was reduced and biodiesel was synthesized from pretreated oil under microwave irradiation. The process variables such as irradiation time, methanol-oil ratio and sulfuric acid concentration for pretreatment step; irradiation time, methanol-oil ratio and KOH concentration were optimized through the Box-Behnken experimental design. The free fatty acid of crude karanja oil was reduced to 1.11 ± 0.07% with an optimal combination of 190 s irradiation time (180 W), 33.83 (w/w)% methanol-oil ratio and 3.73 (w/w)% sulfuric acid concentration. An optimal combination of 150 s irradiation time, 33.4 (w/w)% methanol-oil ratio and 1.33 (w/w)% KOH concentration yielded 89.9 ± 0.3% biodiesel. The model was validated by conducting experiments at optimal design conditions. The present work confirmed that the microwave energy has a significant effect on esterification and transesterification reaction. © 2010 Elsevier B.V. All rights reserved.Item Excess and deviation properties of {(glycylglycine + ZnCl2) in aqueous methanol} mixtures(2011) Santosh, M.S.; Bhat, D.K.The excess molar volumes (VE), viscosity deviations (??), deviations in isentropic compressibility (?? S) and excess molar refractivity (?RmE) for {(glycylglycine + ZnCl2) in aqueous methanol} mixture have been calculated from the experimental values. The bridging water molecules bend the chains into stable open ring structures together with intermolecular hydrogen bonding and interstitial accommodation leading to negative VE values. The positive ?? values indicate a structure breaking effect of aqueous glycylglycine-ZnCl2 upon contact with methanol molecules. It is also noted that chelation of zinc to glycylglycinate is through carboxylic group and not the amino group. The negative ??S values suggest the formation of an open ring structure lowering the entropy of the solution. Due to weak interaction between solute and solvent, the molecular structure of individual molecule does not change significantly and leads to negative ?RmE values. Finally, the results have lead to a good understanding of the thermodynamics properties of the studied liquid mixture. © 2010 Elsevier Ltd. All rights reserved.Item Kinetics of esterification of acetic acid with methanol in the presence of ion exchange resin catalysts(2011) JagadeeshBabu, P.E.; Sandesh, K.; Saidutta, M.B.Esterification kinetics of acetic acid with methanol was studied with solid acid catalyst in an isothermal batch reactor at 333-353 K. Different types of ion exchange catalyst (Indion 130, Indion 190, and Amberlyst 15 wet) were used for the esterification of acetic acid. It was found that Indion 130 was an effective catalyst for acetic acid esterification. The effects of stirrer speed, reaction temperature, initial reactant concentration, and catalyst loading on reaction rate were investigated and optimized. Temperature dependence of the reaction rates and activation energies was determined by an Arrhenius plot. A complete kinetic equation for describing the reaction catalyzed by Indion 130 was developed. This equation can be used in the simulation and design of the catalytic distillation column for the synthesis of methyl acetate. © 2011 American Chemical Society.
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