Faculty Publications
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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 Two-step biodiesel production and its kinetics studies using indion-190/amberliteira-900 from waste cooking oil(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2015) Satheesh, K.; JagadeeshBabu, P.E.; Saidutta, M.B.Free fatty acid of waste cooking oil was reduced through esterification using Indian-190 and then transesterified using AmberliteIRA-900 to produce biodiesel. Maximum conversion of 93.69% was observed during esterification at optimized conditions (temperature: 337 K; duration: 4 h; methanol:oil: 20:1; catalyst: 8 wt%). Biodiesel conversion of 98.69% was observed with a yield of 80% through transesterification. Temperature dependence was analyzed using the Langmuir-Hinshelwood model. Activation energy of 134.952 kJ/mol and a frequency factor of 5.49 × 1015 min-1 were observed. Thermodynamic parameters were determined using the Vant Hoff plot. Properties of biodiesel were found to be within ASTM standard. Reusability of Indion-190 was analyzed for five cycles, and found to be satisfactory. © © © Taylor & Francis Group, LLC.Item Studies on the Solid Oxide Cell Perovskite Electrode Materials for Soot Oxidation Activity(Springer, 2019) Shenoy, C.S.; Patil, S.S.; Govardhan, P.; Shourya, A.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.Solid oxide cell (SOC) perovskite electrode materials (BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-?), LSCF (La0.6Sr0.4Co0.2Fe0.8O3-?) and LSCM (La0.75Sr0.25Cr0.5Mn0.5O3-?)) were synthesised using microwave-assisted reverse-strike co-precipitation method and tested for soot oxidation activity. The calcined perovskite materials were characterized using FT-IR, XRD, SEM and BSE, BET and BJH and XPS analysis. The mean activation energy for soot oxidation was calculated from Ozawa plots at various heating rates (5, 10, 15 and 20 K/min) at different levels of soot conversions (T10 to T90) for BSCF, LSCM and LSCF perovskite materials and was around 133 ± 11.5, 138 ± 9.9 and 152 ± 7.2 kJ/mol, respectively. Irrespective of the heating rates, BSCF material showed the lowest T50 temperature than compared to other samples, and it is correlated to the presence of Fe3O4 as a secondary phase. © 2019, Springer Nature Switzerland AG.Item Effect of sintering aids on sintering kinetic behavior of praseodymium doped ceria based electrolyte material for solid oxide cells(Elsevier Ltd, 2020) Shajahan, I.; Prasad Dasari, H.P.; Saidutta, M.B.The present study investigates the effect of sintering additives (Li, Co, Fe, and Mg) on the sintering kinetic behavior of the praseodymium-doped-ceria (PDC) electrolyte of solid oxide electrolyzer cell. 3Li-PDC, 3Co-PDC, 3Fe-PDC, and 3 Mg-PDC pellets were obtained from the synthesis of PDC nano-powder by microwave-assisted co-precipitation method using isopropyl alcohol as a solvent and followed by sintering additive wetness impregnation method. Linear shrinkage and shrinkage rate data suggest a positive sintering effect for 3Li-PDC and 3Co-PDC pellets and a negative sintering effect for 3 Mg-PDC and 3Fe-PDC pellets than compared to PDC pellets alone. The addition of lithium as a sintering additive (3Li-PDC) had reduced the sintering temperature of PDC from 1100 °C to 850 °C. For PDC, 3Li-PDC, 3Co-PDC, 3Fe-PDC and 3 Mg-PDC pellets sintered at 1100 °C, 850 °C, 1000 °C, 1200 °C, 1100 °C for 2 h resulted in a relative density of 93.6 ± 0.25, 95.8 ± 0.45, 95.0 ± 0.20, 92.7 ± 0.10, and 94.5 ± 0.10%, respectively. The XRD patterns of the sintered PDC pellets suggested a secondary phase formation (PrO2) in 3Co-PDC, 3Fe-PDC, and 3 Mg-PDC pellets indicating that the addition of these sintering aids results in poor solubility limit of Pr in CeO2. On the other hand, XRD patterns of PDC and Li-PDC sintered pellets displayed no secondary peak indicating good solid-solution formation. The activation energy of the 3Li-PDC pellet is obtained from CHR and Dorn methods and was found to be 182 kJ/mol and 196 kJ/mol. From the CHR method, for the 3Li-PDC pellet, the initial sintering behavior is by the grain boundary diffusion mechanism (m = ~2). © 2020 Hydrogen Energy Publications LLCItem Promotional effect of nickel addition on soot oxidation activity of Ce0.9Pr0.1O2 oxide catalysts(Springer, 2020) Rajvanshi, K.; Patil, S.S.; Lakhanlal, u.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.The present study investigates the promotional effect of Ni addition on soot oxidation activity of Ce0.9Pr0.1O2 oxide catalysts. A series of xNi-PDC (x= 0, 3, 5, 7, 10, 15, and 20 mol%) catalysts were synthesized by solution combustion synthesis method and characterized by XRD, Raman spectroscopy and TEM analysis. XRD and SAED patterns of the catalysts show cubic fluorite structure of ceria with an average crystallite size of 6–8 nm, and only 20Ni-PDC display NiO as a secondary phase. Raman spectra of xNi-PDC catalysts display an increase in oxygen vacancies. With a minimum addition of 10 mol% Ni to PDC, i.e., the 10Ni-PDC catalyst showed optimum soot oxidation activity (T50 = 360 °C) than compared to PDC and other Ni-PDC catalysts. Lattice strain and oxygen vacancies played a key descriptor role in showing better soot oxidation activity of the 10Ni-PDC catalyst. From the soot oxidation kinetic studies, the activation energy obtained by Ozawa plots for the 10Ni-PDC catalyst is 137 kJ/mol. © 2020, Institute of Chemistry, Slovak Academy of Sciences.Item Electrical conductivity studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2022) Srijith; Lakhanlal, u.; Das, A.; Prasad Dasari, H.P.; Saidutta, M.B.In this study, the electrical conductivity of the LAMOX based electrolytes (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) synthesized by the citrate complexion method has been studied using DC four-probe method. The electrical conductivity of the electrolytes is measured in the temperature range of 800–400 °C in the air (∼100 ml min−1). The effect of W and Ga substitution at the Mo site on the electrical conductivity is evaluated. The long-term electrical conductivity stability test (time on stream) (5 h) is conducted at 650, 580, and 520 °C to study the effect of possible phase transition on electrical conductivity. A high-temperature XRD study is also conducted in the temperature range of 500–650 °C (during heating and cooling) on selected electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0 and 0.1) and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) to study the α↔β phase transition. The electrical conductivity of these electrolytes in the air at 800 °C is in the range of 5.3 × 10−2 – 14 × 10−2 S cm−1. The activation energy (EA) of these electrolytes is in the range of 1.11–1.62 eV. The VTF parameters σo, B, and To are in the range of 67.46–395.88 S cm−1 K0.5, 0.122–0.254 eV, and 247–347 °C, respectively. The La1.8Dy0.2Mo2-xWxO9 (x = 0.1) shows highest electrical conductivity (14 × 10−2 S cm−1, EA = 1.54 eV) among all electrolytes in air at 800 °C and for this material the VTF parameters σo, B, and To are 170.32 S cm−1 K0.5, 0.153 eV, and 302 °C, respectively. © 2022 Elsevier Ltd and Techna Group S.r.l.