Faculty Publications
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Item The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over catalysts containing iron impregnated on activated carbon. Iron was impregnated on various surface modified activated carbons. The catalyst that was made by treating activated carbon with nitric acid, that was treated thermally in the presence of nitrogen at 600 °C and impregnated with 5 wt.% iron, gave a phenol yield of 20%. It was found that the synergistic interactions of surface groups and the impregnated iron have enhanced the performance of these catalysts. © 2005 Elsevier B.V. All rights reserved.(Direct synthesis of phenol from benzene on iron-impregnated activated carbon catalysts) Choi, J.-S.; Kim, T.-H.; Choo, K.-Y.; Sung, J.-S.; Saidutta, M.B.; Ryu, S.-O.; Song, S.-D.; Badekai Ramachandra, B.; Rhee, Y.-W.2005Item 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 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.Item Solar photocatalytically active, engineered silver nanoparticle synthesis using aqueous extract of mesocarp of Cocos nucifera (Red Spicata Dwarf)(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Sumi, M.B.; Devadiga, A.; Shetty K, V.K.; Saidutta, M.B.Silver nanoparticles synthesised using aqueous extract of Cocos nucifera (CN) mesocarp were evaluated for their photocatalytic activity under solar irradiation. The silver nanoparticles were synthesised by a green method of harnessing bioactive phytocomponents from the mesocarp of Cocos nucifera. Large-scale application of this process necessitates the manoeuvering of the process parameters for increasing the conversion of silver ions to nanoparticles. Process parameters influencing the morphological characteristics of silver nanoparticles such as precursor salt concentration and pH of the synthesis mixture were studied. The crystalline nanoparticles were characterised using UV-vis spectroscopy, XRD, FTIR, SEM and EDX analysis. CN extract and 5 mM silver nitrate solution at a ratio of 1:4 (v/v) in the synthesis mixture was found to be the optimum. Alkaline initial pH of the synthesis mixture was found to favour the synthesis of smaller sized monodispersed silver nanoparticles. Solar energy was harnessed for the photocatalytic degradation of Malachite green dye using silver nanoparticles obtained through the green synthesis method. Overall process aims at utilisation of naturally available resource for the synthesis of silver nanoparticles as well as the degradation of dyes using these nanoparticles, making it useful in the treatment of wastewater. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Item Highly stable silver nanoparticles synthesized using Terminalia catappa leaves as antibacterial agent and colorimetric mercury sensor(Elsevier B.V., 2017) Devadiga, A.; Shetty K, K.V.; Saidutta, M.B.Silver nanoparticles (AgNPs) were synthesized using the aqueous extract of an agrowaste: Terminalia catappa leaves. The AgNPs were characterized using UV–VIS spectroscopy, Transmission electron microscopy, Scanning electron microscopy, Fourier Transmission Infrared spectroscopy and Dynamic light scattering analysis. AgNPs were monodispersed, crystalline, quasi-spherical with average size of ?11 nm and were encapsulated with capping agents present in the extract. The AgNPs were stable with the zeta potential value of ?36.7 mV. These AgNPs exhibited significant antibacterial activity against water borne pathogens and could be used as colorimetric sensors for the detection of trace levels of mercury, indicating their multifaceted application in antibacterial coating, water treatment and as colorimetric mercury sensors. The overall synthesis process emphasizes on the agrowaste utilization for the “green” synthesis of AgNPs. © 2017 Elsevier B.V.