Browsing by Author "Iyyaswami, I."

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1-Hexyl-3-Methylimidazolium Chloride-Potassium Carbonate Aqueous Two Phase System: Equilibrium Characteristics and BSA Partitioning Behavior
(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2014) Iyyaswami, I.; Monteiro, S.L.
The partitioning behavior of the model protein (bovine serum albumin) was investigated in ionic liquid (1-hexyl-3-methylimidazolium chloride) -salt (potassium carbonate) based aqueous two phase system (ATPS). The phase diagram with binodal curve and tie lines for the selected ATPS was developed at different temperatures and analyzed through effective excluded volume (EEV) and Othmer-Tobias and Bancroft equations, respectively. The influence of various process parameters like the ionic liquid and salt concentration, system temperature, tie line length, phase volume ratio, and neutral salt addition on partition coefficient/extraction efficiency of BSA protein was evaluated. © 2014 Copyright Taylor & Francis Group, LLC.
An empirical model for the estimation of moisture ratio during microwave drying of plaster of Paris
(2008) Ganesapillai, M.G.; Iyyaswami, I.; Murugesan, T.
The drying characteristics of plaster of Paris (POP) under microwave irradiation were studied for different shapes of materials through various drying parameters like microwave power, initial moisture content, and drying time. An empirical model for the estimation of moisture ratio was developed using the drying kinetic data of POP. Further, the experimental data on moisture ratio of POP for different operating conditions were fitted with the nine basic drying model equations. Based on the observations, the constants and coefficients of the literature models were rewritten in the form of Arrhenius and logarithmic expressions considering microwave power as input variable. Fifty-eight new model expressions were derived by changing the constants and coefficients and tested using the present experimental data. From the analysis of RMSE, ?2, and EF parameters for the derived models, a suitable empirical model (Model No. 55, RMSE = 0.0874; ?2 = 0.0020; EF = 0.9999) was established to represent the present experimental data on microwave drying of POP.
An optimization study on microwave irradiated, decomposition of phenol in the presence of H2O2
(2009) Prasannakumar, B.R.; Iyyaswami, I.; Murugesan, T.
Background: Removal of phenol from industrial waste waters involves basic techniques namely extraction, biodegradation, photocatalytic degradation, etc. Among the available processes, the oxidation of phenols using H2O2 is a suitable alternative because of low cost and high oxidizing power. The application of an oxidation process for the decomposition of stable organic compounds in waste water leads to the total degradation of the compounds rather than transferring from one form to another. Since oxidation using Fenton's reagent ismore dependent on pH, in this present work it was proposed to use H2O2 coupled with microwave irradiation. The effects of initial phenol concentration, microwave power and the irradiation time on the amount of decomposition were studied. Results: In the present work experiments were conducted to estimate the percentage degradation of phenol for different initial concentrations of phenol (100, 200, 300, 400 and 500 mg L-1), microwave power input (180, 360, 540, 720 and 900 W) for different irradiation times. The kinetics of the degradation process were examined through experimental data and the decomposition rate follows first-order kinetics. Response surface methodology (RSM) was employed to optimize the design parameters for the present process. The interaction effect between the variables and the effect of interaction on to the responses (percentage decomposition of phenol) of the process was analysed and discussed in detail. The optimum values for the design parameters of the process were evaluated (initial phenol concentration 300 mg L-1, microwave power output 668 W, and microwave irradiation time 60 s, giving phenol degradation 82.39%) through RSM by differential approximation, and were confirmed by experiment. Conclusion: The decomposition of phenol was carried out using H2O2 coupled with microwave irradiation for different initial phenol concentrations, microwave power input and irradiation times. The phenol degradation process follows first-order kinetics. Optimization of the process was carried out through RSM by forming a design matrix using CCD. The optimized conditions were validated using experiments. The information is of value for the scale up of the oxidation process for the removal of phenol from wastewater. © 2008 Society of Chemical Industry.
Analysis of ionic and nonionic surfactants blends used for the reverse micellar extraction of Lactoperoxidase from whey
(John Wiley and Sons Ltd, 2021) Karanth, S.; Iyyaswami, I.
Bovine Lactoperoxidase (LP), a minor whey protein, is used as an antimicrobial in cosmetic, food, and pharmaceutical preparations. Industries are in pursuit of reliable, cheap, and scalable purification methods as the conventional techniques for LP purification like chromatography and membrane separation suffer from several drawbacks. The present work investigates the selective reverse micellar extraction of LP using the reverse micellar system formed by mixing food grade nonionic (Tween, Span, and Triton series) and ionic (AOT) surfactant blends. The analysis of LP extraction efficiency was performed by varying the concentration of nonionic surfactants with a constant AOT concentration of 100 mM and the initial pH of the system. Complete LP solubilization was achieved with reverse micelles formed by 100 mM AOT and 20 mM Tween 80 at pH 8. It was found that the extraction efficiency was dependent on the chain length or the number of ethylene oxide units in the Triton surfactant tail and the carbon–carbon double bond in Tween 80 tail, that is, on oleic acid. Span series however showed poor extraction in the organic phase substantiating the lesser water content. The forward extracted LP was successfully back-extracted into a fresh aqueous phase containing 1 M KCl at pH 10.5. The aqueous phase (whey) from the forward transfer can be further used to fractionate other whey proteins. © 2020 Curtin University and John Wiley & Sons, Ltd.
Characterization and process optimization of microwave drying of plaster of Paris
(2008) Ganesapillai, M.G.; Iyyaswami, I.; Murugesan, T.
The changes in the characteristics of plaster of Paris (pop) during drying operation under microwave irradiation conditions, namely surface morphology, effective moisture diffusivity, and absorption of microwave, were studied. The drying characteristics and kinetics of the process during microwave drying of plaster were studied for rectangular-faced cuboids (80 × 70 × 15, L × B × H in mm) through various drying parameters like microwave power input, initial moisture content, and drying time. Further, the experimental data on moisture ratio of plaster for different operating conditions were obtained and the optimization of the microwave drying process parameters was performed with response surface methodology (RSM) by considering all the above-said independent variables. Based on the RSM analysis, the optimum values of the process variables were obtained as: initial moisture content (A) 60%; microwave power input (B) 180 W; and drying time (C) 480 S.
Continuous aqueous two-phase extraction of ?-lactalbumin from whey in conventional rotating disc contactor
(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2016) Kalaivani, S.; Iyyaswami, I.
The differential partitioning of ?-La to the PEG-rich phase and ?-Lg to the salt-rich phase was studied in the continuous extractor, rotating disc contactor (RDC), using polyethylene glycol (PEG) 1000–trisodium citrate system. The performance of the extractor was evaluated in terms of holdup, mass transfer coefficient, extraction efficiency, and recovery by studying the operating variables such as phase velocities and rotor speed. The process conditions for the maximum dispersed phase mass transfer coefficient and recovery of ?-La was also obtained and reported. © 2016 Taylor & Francis.
Densities and viscosities of binary and ternary mixtures and aqueous two-phase system of poly(ethylene glycol) 2000 + diammonium hydrogen citrate + water at different temperatures
(2012) Kalaivani, S.; Srikanth, C.K.; Iyyaswami, I.
The densities and viscosities of aqueous solutions of poly(ethylene glycol) (PEG-2000) and diammonium hydrogen citrate were determined for mass fractions from 0.05 to 0.5 at different temperatures of (298.15, 303.15, 308.15, 313.15, and 318.15) K. The density data show a linear variation with mass fraction of the polymer and salt for all temperatures. The viscosity data of PEG 2000 and diammonium hydrogen citrate solutions were correlated as a function of mass fraction, using a nonlinear equation, for the five different temperatures covered in the present work. Densities and viscosities of PEG-diammonium hydrogen citrate two-phase systems have also been measured at (298.15, 303.15, 308.15, 313.15, and 318.15) K and are correlated with composition. The tie-line lengths (TLL) of the aqueous two-phase systems have also been estimated. © 2012 American Chemical Society.
Densities and viscosities of poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water systems
(2009) Iyyaswami, I.; Murugesan, S.; Amaresh, S.P.; Govindarajan, R.; Murugesan, T.
The densities and viscosities of binary and ternary solutions of the poly(ethylene glycol) 4000 (PEG4000) + diammonium hydrogen phosphate + water system were determined at different temperatures [(298.15, 303.15, 308.15, 313.15, and 318.15) K]. The measured density and viscosity data of all the binary and ternary systems were fitted to available empirical correlations, for the corresponding temperatures. The density data show a linear variation with mass fraction of the polymer for all temperatures. The viscosity data of all the solutions were correlated as a function of their mass fraction, using a nonlinear equation, for the five different temperatures covered in the present work. Densities and viscosities of PEG4000 - diammonium hydrogen phosphate two-phase systems have been measured at (298.15, 303.15, 308.15, 313.15, and 318.15) K. The tie line lengths (TLL) of the aqueous two-phase systems have also been estimated, and the effect of the physical properties on the TLL is also reported. © 2009 American Chemical Society.
Densities and viscosities of polyethylene glycol 6000 + triammonium citrate + water systems
(2009) Iyyaswami, I.; Govindarajan, R.; Amaresh, S.P.; Murugesan, T.
The densities and viscosities of binary and ternary solutions of the aqueous two-phase systems created by the polyethylene glycol 6000 + triammonium citrate + water system were measured at different temperatures [(25, 30, 35, 40, and 45) °C] and correlated with empirical equations. The density data were compared with those available in the literature. The density data show a linear variation with the mass fraction of the polymer for all temperatures. The density and viscosity of the top and bottom phases were also measured and reported. © 2009 American Chemical Society.
Development and Evaluation of PEG-Lithium Citrate Salt Based Aqueous Two Phase System and Its Application in Partitioning of Proteins from Fish Industry Effluent
(2012) Iyyaswami, I.; Belur, P.D.; Girish, B.; Nagaraj, V.H.
A aqueous two phase system (ATPS) comprising of PEG (Average mol. Wt: 4000, 6000, 8000) - lithium citrate salt-water systems were studied. The basic studies like binodal curve data generation and equilibrium studies were carried out. Furthermore, the binodal model and Othmer-Tobias and Bancroft models for phase equilibria were used for reproducing the experimental binodal data and phase equilibrium composition data, respectively. Good agreement was obtained with the experimental binodal data and tie line data with the models. The effective excluded volume values were obtained from the binodal model for the present ATPS. The tie line length was determined through the phase equilibrium composition data. This system was used to partition crude proteins of the fish industry effluent. The effects of PEG and salt weight fraction in terms of tie line length and effective excluded volume on partitioning coefficient of crude protein were studied in detail. From the results it was observed that, the crude proteins present in the fish effluent were partitioned in the PEG rich phase and the maximum partition coefficient of 7.82 was obtained. The results are discussed in the context of practical potential of this citrate based ATPS in separating crude proteins from fish industry effluent. © 2012 Copyright Taylor and Francis Group, LLC.
Dissolution of kraft lignin using Protic Ionic Liquids and characterization
(Elsevier B.V., 2016) Rashid, T.; Chong, C.F.; Iyyaswami, I.; Murugesan, T.
In the present research three Protic Ionic Liquids (pyridinium formate, pyridinium acetate and pyridinium propionate) were synthesized and tested for the dissolution and subsequent regeneration of kraft lignin. Among the investigated solvents, pyridinium formate showed a higher dissolution capacity (70% w/w) i.e. (710 g/L) at 75 °C within 1 h. The results indicated that the introduced solvent is thermally stable, noncorrosive, possesses low viscosity and is easy to recycle. The dissolution process is purely physical and the physicochemical analysis of the regenerated lignin showed high thermal stability, with reduction in polydispersity and the average molecular weight was reduced from 4119 g/mol to 1249 g/mol. FTIR spectroscopy and 1H NMR results proved that the regenerated lignin is less degraded. Moreover the OH vibrations of regenerated lignin showed a weak inter and intramolecular interaction in regenerated lignin, which could positively help in reducing its chemical resistance towards processing for further commercial applications. Due to the higher solubility of lignin and its stability towards recyclability, the pyridinium formate proved that present selective dissolution and regeneration of lignin could significantly enhance the pretreatment techniques for lignocellulosic biomass. © 2016 Elsevier B.V.
Drag reduction in co-current down flow packed column using xanthan gum
(2010) Iyyaswami, I.; JagadeeshBabu, P.E.; Chitra, M.; Murugesan, T.
Drag reduction is one of the most important techniques for reducing energy consumption in a packed bed contactor. The present work involves an experimental investigation on flow regime transition for air-water system with and without drag reducing agent (DRA), two-phase pressure drop, friction factor and drag reduction using xanthan gum as DRA. Drag reduction was quantified from the two-phase pressure drop data. Based on the present observations it was found that the percentage drag reduction increases with an increase in the concentration of DRA and it is only effective in the range of 300 ppm to 800 ppm. The experimental results indicate that a maximum of 80% drag reduction was achievable using xanthan gum (800 ppm) as DRA. Furthermore, the experimental data were validated with the available literature correlations. © 2010 Korean Institute of Chemical Engineers, Seoul, Korea.
Effect of intrinsic and extrinsic factors on the storage stability of sardine oil
(Enviro Research Publishers publisher@enviropublishers.com, 2019) Charanyaa, S.; Belur, P.D.; Iyyaswami, I.
Oil extracted from pelagic fishes, rich in n-3 polyunsaturated fatty acids (PUFA) like Eicosapentaenoic acid and Docosahexaenoic acid, have numerous health benefits. The oil also contains impurities like di- and mono glycerides, free fatty acids, phospholipids, unsaponifiable matter, metal ions and volatile compounds. Most of these impurities are removed by refining process without affecting valuable n-3 PUFA. However, due to the presence of residual impurities, environmental factors and higher degree of unsaturation, the oil exhibit hydrolytic and oxidative instability during storage. This study was aimed to identify the most detrimental factors causing hydrolytic and oxidative instability and deterioration of n-3 PUFA content in sardine oil during five-week storage. The effect of various extrinsic and intrinsic factors on the storage stability was investigated. The hydrolytic and oxidative instability was estimated by free fatty acid (FFA) content and totox value (TV) respectively. Moisture, sunlight, ferric ions and FFA were found to be most detrimental to oil quality and n-3 PUFA content. Although, addition of phosphotidylcholine and phospholipase-A showed high degree of hydrolytic and oxidative instability, n-3 PUFA destruction was minimal. Interestingly, even in the presence of ferric ions and FFA, phosphotidylcholine and phospholipase-A exhibited n-3 PUFA protection. The exact mechanism by which phosphotidylcholine and phospholipase-A offered protection to n-3 PUFA needs further investigation. From this study, it can be concluded that removing ferric ions, moisture and FFA from crude oil during refining is essential. Further, the refined oil must be stored under dark conditions in airtight containers to retard deterioration of oil quality. © 2019 The Author(s). Published by Enviro Research Publishers.
Insitu gasification – chemical looping combustion of large coal and biomass particles: Char conversion and comminution
(Elsevier Ltd, 2021) Pragadeesh, K.S.; Iyyaswami, I.; Ruben Sudhakar, D.
Utilization of large solid fuel particles in fluidized bed – Chemical Looping Combustion (CLC) has the benefits of reduced energy penalty related to carbon capture. When large fuel particles (mm-sized) are used, comminution plays a vital role in the fuel conversion rate, characteristics of ash, inventory loading and thus in the effective design of CLC systems. The present work deals with the conversion of char of large fuel particles and char fragmentation phenomenon in the insitu-gasification CLC environment. Three different coals and a woody biomass in the size range of + 8–25 mm are tested at three different bed temperatures (800 to 950 °C) in a hematite-based batch CLC unit, using steam as the fluidizing/gasification agent. The char conversion time is found to increase by 60 to 170% when particle size changes from 8 to 25 mm and reduced by 42 to 86% with the increase in bed temperature. Regardless of fuel type and feed size, the inception of char fragmentation is noticed in the very first quarter of conversion indicating its significant influence on the char burnout time. A minimum critical char size exists below which char weakening does not yield breakage, whose values vary between 4.4 and 14.2 mm depending on fuel type and feed size. Fuel type is found to be the prime influencer of char conversion time and fragmentation phenomena. This study recommends the use of large particles of all fuels up to 25 mm in CLC systems without any prior size reduction, except the high-ash coals. © 2021 Elsevier Ltd
Interfacial area and mass transfer coefficients in liquid-gas ejectors
(2011) Arunagiri, A.; Iyyaswami, I.; Murugesan, T.
Measurements and correlations are reported for the interfacial area and mass transfer coefficients as a function of energy dissipation in a liquid-gas ejector. The correlations for interfacial area and mass transfer coefficients have been developed using Kolmogorov's theory and Levich's hydrodynamic derivations. The present developed correlations are validated using experimental results. © 2011 Pleiades Publishing, Ltd.
Investigating the solubility of petroleum asphaltene in ionic liquids and their interaction using COSMO-RS
(Korean Society of Industrial Engineering Chemistry A-803 Twin Bldg 275-3 Yangjae-Dong Seocho-Kul Seoul 137-130, 2019) Rashid, Z.; Wilfred, C.D.; Iyyaswami, I.; Arunagiri, A.; Murugesan, M.
Dispersion of asphaltene in crude oil using ionic liquids (ILs) is being considered as a viable solution, in extraction and transportation processes. In this work, the interplay between asphaltene and ILs has been studied systematically to understand the effect of structural variation of ILs on asphaltene solubility. The activity coefficient of the total of 1517 ILs with different combinations of cation and anion of ILs for representative asphaltene molecule (asphaltene) was estimated via COSMO-RS (Conductor-like Screening Model for Real Solvents). COSMO_RS predictions were validated using experimental data on asphaltene solubility. Among the studied ILs, asphaltene showed high solubility in imidazolium-based ILs with hydrophobic anions. The present approach paved a way forward to rationally understand the impact of structural variation of ILs on their interaction with asphaltene molecule and to design new ILs for the dispersion and stabilization of asphaltene. © 2019 The Korean Society of Industrial and Engineering Chemistry
Liquid-liquid equilibrium of poly(ethylene glycol) 2000 + diammonium hydrogen citrate + water system at different temperatures
(2011) Iyyaswami, I.; Srikanth, C.K.; Sindhu, N.
Phase diagrams and liquid-liquid equilibrium (LLE) data of the aqueous poly(ethylene glycol) (PEG-2000) + diammonium hydrogen citrate system (aqueous two-phase system) has been determined experimentally at (298.15, 303.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodal curve and tie-lines have been studied. The binodal curve was fitted to an empirical equation relating the concentrations of PEG 2000 and diammonium hydrogen citrate, and the coefficients were estimated for the respective temperatures. Tie line compositions were estimated and correlated using Othmer-Tobias and Bancroft equations, and the parameters are reported. The effect of temperature on the phase-forming ability in the investigated system has been studied based on a salting-out coefficient; obtained from fitting the binodal data to a Setschenow-type equation for each temperature. The effective excluded volume values were also calculated from the binodal data. © 2011 American Chemical Society.
Liquid-liquid equilibrium of poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water at different temperatures
(2008) Amaresh, S.P.; Murugesan, S.; Iyyaswami, I.; Murugesan, T.
Liquid-liquid equilibrium for an aqueous two-phase system containing poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water was studied at four different temperatures of (25, 30, 35, and 45)°C. The binodal curve was fitted to three different empirical equations relating the concentrations of PEG 4000 and diammonium hydrogen phosphate, and the coefficients were estimated for the respective temperatures for all three equations. The effective excluded volume values were obtained from the binodal model for the present system, and salting-out ability of the salt was discussed. Tie line compositions were correlated using the Othmer-Tobias and Bancroft equations, and the parameters are also reported. Further, the experimental binodal data of the poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water system were compared to poly(ethylene glycol) 6000 + diammonium hydrogen phosphate + water for (25, 35, and 45)°C. © 2008 American Chemical Society.
Liquid-liquid equilibrium of poly(ethylene glycol) 6000 + triammonium citrate + water systems at different temperatures
(2009) Iyyaswami, I.; Murugesan, S.; Govindarajan, R.; Amaresh, S.P.; Murugesan, T.
Liquid - liquid equilibrium for an aqueous two-phase system containing poly(ethylene glycol) 6000 + triammonium citrate + water was studied at five different temperatures, (25, 30, 35, 40, and 45) °C. The binodal curve was fitted to an empirical equation relating the concentrations of PEG 6000 and triammonium citrate, and the coefficients were estimated for the respective temperatures. The effective excluded volume values were obtained from the binodal data. Tie line compositions were estimated and correlated using Othmer - Tobias and Bancroft equations, and the parameters are reported. © 2009 American Chemical Society.
Microwave-assisted batch and continuous transesterification of karanja oil: Process variables optimization and effectiveness of irradiation: Microwave-assisted transesterification of karanja oil
(Springer Verlag service@springer.de, 2013) Iyyaswami, I.; Venkatesh Kamath, V.K.; Yarramreddy, S.R.; Malur Bharathaiyengar, S.
The technological advancement in biodiesel production has been the focus area for last the few years and microwave-assisted biodiesel synthesis is one such promising new technology. In the present investigation, microwave irradiation was used to produce biodiesel from non-edible Karanja (Pongamia pinnata) oil in batch and continuous mode. Experiments were conducted to understand the effect of volume of the reaction mixture, irradiation time, and irradiation power on the yield of biodiesel. To increase the effectiveness of the microwave irradiation, biodiesel was synthesized in a continuous tubular reactor at two different holdup volumes. The effect of process parameters viz., irradiation time, irradiation power, and methanol to oil ratio were optimized using Box-Behnken experimental design. The effectiveness of microwave irradiation for the different process conditions have been represented through an effectiveness factor. The results reinforce the advantages of continuous processes over batch processes for the production of biodiesel. The properties of biodiesel, namely ester content, density, viscosity, acid value, and cetane index were analyzed and found to be within the limits as prescribed in ASTM D6751-09 standards. The experimental results that have been obtained in this study would be very useful in the scale-up of the microwave-assisted biodiesel process. © 2013 Springer-Verlag Berlin Heidelberg.