PhD Theses (Chemical Engineering)
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Item Studies on Pyrolysis Kinetics of Commodity Plastics(2007) Saha, BiswanathNoncatalytic and catalytic decomposition behaviour of commodity plastics such as waste and virgin polyethylene terephthalate(PET), waste low density polyethylene(LDPE), waste polyethylene(PE) and pure polypropylene(PP) are carried out using thermogravimetric analyzer(TGA). Catalyst used in this study are commercially available ZSM-5, fresh and spent FCC catalysts, laboratory synthesized sol-gel and hydrothermal mesoporous catalysts A1-MCM-41 of different aluminium contents and high external surface area containing nanocryystalline n-HZSM-5. polymer samples characterized by differentials scanning calorimetry(DSC)...Item Physical Features of Sonochemical Degradation of Recalcitrant Organic Pollutants(2008) Sivasankar, T.The toxic organic pollutants contributed by industrial wastewater and agricultural runoffs are complex refractory molecular which are not easily degraded by conventional biological techniques...Item Absorption of CO2 by Single and Blended Amine Solvents in Various Gas–Liquid Contactors(2008) Paul, SubhamIn this work the absorption of CO2 into aqueous solutions of sterically hindered and blended amines is considered. A kinetic study is carried out for the reaction of CO2 into aqueous solutions of two important single sterically hindered alkanolamines, 2-piperidineethanolamine (2-PE) and 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) at 303, 313 and 323 K for a range of amine concentrations using a fabricated wetted wall column absorber. The reaction is satisfactorily described using a zwitterionic mechanism. The hydrolysis of the carbamate ion to form bicarbonate ion considered in the reaction mechanism is confirmed by 13C NMR spectroscopy. The reaction orders are found to be around 1.0 with respect to amines for both systems. The second order rate constants, k2, are obtained from the experimental results which are correlated using Arrhenius equation. Kinetics of absorption of CO2 into a new activator such as 2-(1-piperazinyl)-ethylamine (PZEA) and into the blends of PZEA and N-methyldiethanolamine (MDEA) are also carried out. The reaction of CO2 with PZEA is described by overall second order reaction. The addition of small amounts of PZEA to (MDEA + H2O) is found to be significantly enhancing the reaction rate. In order to study the effects of different physicochemical and kinetic parameter on calculated CO2 absorption rates into aqueous solutions of (2-PE + H2O),(AHPD + H2O) and (PZEA + H2O), a parametric sensitivity analysis is investigated for which a series of simulation runs are carried out. The parameters considered for the analyses are Henry’s law constant for CO2, diffusivity of CO2 into the amine solutions and the second order reaction rate constants for the absorption of CO2. The kinetic study carried out in this work should be useful for the rational design of gas treating processes employing single or blended alkanolamine solvents. Physicochemical properties of CO2 and the aqueous alkanolamine solvents needed in the kinetic study are measured in this work, extending the data in the literature for the specific single and blended amine solvents studied in this work. The diffusion coefficients and physical solubilities of N2O in the aqueous alkanolamine solutions are measured and the diffusivities and physical solubilities of CO2 in these solvents are estimated by “N2Oanalogy”. The densities and viscosities of the aqueous amine solvents are measured over a wide range of amine concentrations and temperatures. In addition, several correlations developed in this work, will allow prediction of blend properties from single amine properties for process design and research work in gas treating. Besides this kinetic analysis, a theoretical study is carried out using hollow fiber membrane contactor (HFMC) and flat sheet membrane contactor (FSMC) to compare the absorption performance of different aqueous single and blended amine solvents for the absorption of pure and as well as 20% CO2. The performance of different single and blended amine solvents is analyzed in terms of local and average absorption flux of CO2 along the length of fiber or flat membrane. The amine solvent systems considered here are the aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), 2-PE and AHPD as well as aqueous blends of (MEA + MDEA), (MEA+AMP), (DEA + MDEA), (DEA + AMP) and (PZEA + MDEA). The performance of FSMC and HFMC is also compared. The CO2 absorption flux in FSMC is found higher than that in HFMC for all high to low reacting amines.Item Synthesis of Polysulfone Membrane and Its Application to Separation of Oil from Oil-in-Water Emulsion(2008) Chakrabarty, BandanaThe main objective of this work is to synthesize asymmetric polysulfone membranes with required morphological as well as performance properties so th at they can be successfully employed for the removal of micron and submicron sized oil droplets from oily wastewater, generated mainly from the post treatment unit of petroleum refinery sites. the entire effort carried out in this research work can be divided into two main parts: : : Synthesis and characterization of polysulfone membranes. : : Study of applicability of the prepared membranes for the treatment of oily wastewater. ...Item Biodegradation of Phenolic Compounds Using an Indigenous Mixed Microbial Culture(2008) Saravana, P.Biological treatment of wastewater containing phenolic compounds, using indigenous mixed microbial consortium, is the main theme of this thesis. Biological degradation has been advocated to be a better alternative for phenol degradation as opposed to other popular methods for wastewater treatment. Merites of biological treatment and demerites of other methods are also properly discussed in the thesis. ...Item Removal of Fluoride, Iron and Arsenic from Drinking water using a combination of electrocoagulation and Microfiltration(2009) Ghosh, DebasisDifferent parts of the world associated with its adequate presence in the drinking water causes serious damage to health. Different techniques like adsorption, precipitation, membrane separation, ion-exchange, hybrid techniques were reported for the removal of fluoride, iron and arsenic from drinking water. In this work, Electrocoagulation was investigated for the effective removal of fluoride, iron and arsenic from drinking water. Several parameters like initial fluoride, iron and arsenic concentration, current density, electrode connection (monopolar and bipolar), pH, interelectrode distance were found to be dominating in order to remove the above mentioned contaminants from drinking water. Aluminum electrode was considered for the batch mode of electrocoagulation operation. The corrosion of electrodes as well as the sludge formed during the process was estimated. By-products obtained from the electrocoagulation bath were analyzed using SEM, EDAX, FTIR and XRD and explained. Comparative cost estimation for both electrode connections was adopted and presented well. It was found that the drinking water contamination caused by the significant presence of fluoride, iron and arsenic was successfully monitored by the bipolar electrocoagulation for 45 minutes at 625 A m-2 current density and an interelectrode distance of 0.005 m. Electrocoagulation performance was estimated in terms of percentage removal of fluoride, iron and arsenic. Upto 93.2% of fluoride, 99.74% of iron and 95.65% of arsenic removal was achieved. However, electrocoagulated solution was not suitable for the drinking purpose as the solution pH was alkaline along with the agglomerated suspended sludge with size range 10 - 100 Dm. In order to make electrocoagulated solution drinkable, electrocoagulation followed by microfiltration was investigated. In recent times, ceramic microfiltration membranes are being widely used for their better mechanical, thermal and chemical strength compared to the commercial flat-sheet type polymeric membranes. The porous structure of the microporous membranes, mainly composed of ceramic is formed by the process called sintering. In this study ceramic microfiltration membranes were prepared by paste and uni-axial methods. Solid circular ceramic discs of diameter 50 mm and height of 5 mm were prepared and sintered at different temperatures. Five different sintering temperatures were selected (750 DC, 800 DC, 850 DC, 900 DC and 950 DC). The effects of sintering temperature on the structural changes such as porosity, pore-size distribution, average pore radius etc were investigated. All the membranes were characterized using SEM and water permeation test. It was observed that ceramic membranes prepared by both the methods and sintered at 950 DC had sharp pore size distribution. On the other hand, better consolidated microceramic structure was produced by uni-axial cold pressing method. The preparation cost of the ceramic microfiltraton membranes prepared by paste and uni-axial cold pressing methods were 110.62 $/m2 and 135.75 $/m2, respectively...Item Gas adsorption on Cu-BTC and Cr-BDC metal organic frameworks (MOFs)(2009) Chowdhury, PradipMetal organic frameworks have gained considerable attention in recent years. Due to their high surface area and pore volume they are being widely evaluated for potential applications in several areas including adsorption separations, gas storage and catalysis. Early adsorption studies on MOFs concentrated on hydrogen storage; this was followed by evaluation of their potential for CO2 and methane adsorption. Only recently adsorption of other gases is being investigated for their potential applications in adsorptive separations. The aim of this work is two- fold; apart from systematic measurement and analysis of these frameworks for adsorption of several carefully gases with industrial potential, this work also aims to correlate the adsorptive behaviour of the gases to their physical properties. In order to achieve this objective, adsorbate gases themselves, experimental temperature and pressure were carefully chosen for these measurements.Item Preparation and characterization of Low cost ceramic Composite Membranes for Microfiltration and Ultrafiltration Applications(2009) Nandi, Barun KumarIn the past two decades, significant advances in membrane technology research have been reported. Amongst various membrane applications proposed so far, microfiltration (MF) and ultrafiltration (UF) are the most significant in chemical and biochemical processes. Polymeric and ceramic membrane materials are the most relevant materials used for MF and UF membrane processes. While polymeric membranes are inexpensive and are prone to a greater degree of fouling, ceramic membranes are expensive and possess higher corrosion and mechanical resistance. Therefore, the preparation and characterization of low cost ceramic membranes is always encouraging to further the industrial cost effectiveness of membrane technology. This work presents the preparation, characterization and applications of low cost ceramic and polymer - ceramic membranes suitable for MF and UF applications. Among various industrial applications of membranes, treatment of oily wastewater and MF of mosambi juice were chosen as the most important areas of research where low cost ceramic membranes can be used as an alternative to conventional fouling prone polymeric membranes. The entire work carried out in this research work is divided into four major parts: DD Preparation and characterization of comparatively low cost ceramic membranes. DD Application of prepared ceramic membranes for the MF of oil-in-water emulsions. DD Application of prepared ceramic membranes for the MF of mosambi juice. DD Preparation and characterization of polymer-ceramic composite membranes. In this work we have identified two distinct compositions of inorganic precursors (namely composition A and composition B) using kaolin, quartz, feldspar, sodium carbonate, calcium carbonate, boric acid and sodium metasilicate for the preparation of upper (0.547 - 0.810 Dm) and lower (0.185 - 0.332 Dm) submicron pore range ceramic membranes. The identified composition contains 70 - 85 wt % of cheaper precursors and only 15 - 30 wt % of costly precursors. The sintering temperature during membrane fabrication was varied from 800 - 1000 oC, which was lower than usual sintering temperature of 1100 oC as mentioned in various literatures. The prepared ceramic membranes were characterized by TGA/DTA, XRD, SEM analysis, pore size distribution, porosity, average pore size, gas permeation, liquid permeation and chemical stability to evaluate the membrane structural, permeation and chemical characteristics. Based on materials cost, the membrane cost is estimated to be 130 and 220 $/m2 for upper and lower submicron range membranes, respectively. The performance characteristics of the prepared ceramic membranes were studied for the treatment of oil-in-water (o/w) emulsions and MF of mosambi juice in dead end mode of operations. Synthetic o/w emulsions constituting 50 - 250 mg/L oil concentrations were subjected to MF at different trans-membrane pressure differentials (DP ). Membrane prepared with composition A and sintering temperature of 850 oC provided a permeate flux decline from 48.16D 10-6 - 12.24 D 10-6 m3/m2.s where as oil rejection efficiency of the membrane increased from 97.9 - 98.5 % within 30 minutes of experimental run at a of 41.37 kPa for a feed oil concentration of 100 mg/L. The initial permeate flux increased from 48.16 DP D 10-6 - 100.34 D10-6 m....Item Nitration of nitrobenzene at high concentrations of sulfuric acid(2009) Rahaman, MehabubAromatic nitration by mixed acid (a mixture of concentrated nitric and sulfuric acids) is one of the most widely used reactions in the organic chemical industries. Aromatic nitro compounds find wide use in the manufacture of dyes and explosives. It is a heterogeneous liquid-liquid reaction which occurs almost- exclusively in the aqueous phase. The organic compound diffuses into the aqueous mixed- acid phase and reacts with the nitronium ion (NO2+) generated by the reaction between concentrated sulfuric acid and nitric acid. In this thesis, nitration of nitrobenzene using high concentration of sulfuric acid (i.e., between 14 kmol/m3 and 17.2 kmol/m3) was studied in a batch reactor at room temperature and at moderately higher temperatures. Nitration of nitrobenzene is a very slow reaction at room temperature when sulfuric acid concentration is 14.9 kmol/m3 or below due to the deactivating nitro group in the benzene ring. But at high concentration of sulfuric acid (> 16.6kmol/m3) and at high temperatures, the reaction is fast enough to obtain high conversion and yield. The advantage of this reaction is the absence of sulfonation reaction. The behavior of each aromatic nitration system is unique in terms of the physicochemical properties of the heterogeneous organic acid mixture.Item Liquid Membrane Based Technology for Removel of Pollutants from Wastewater(2010) Chakrabarty, KabitaLiquid membrane (LM) technology has drawn attention of the research community since the early D90s and it has increased manifold in recent years. This thesis aims at exploring the efficacy of LM technology for the separation and pre-concentration of lignosulfonate (LS) and mercury (II) from their aqueous solutions. A suitable LM that can extract the said solutes is identified through equilibrium study. Experimentation with various solvents and carrier agents reveal that the dichloroethane (solvent) and trioctylamine (carrier) are the best combination for separation of the LS and Hg(II). The performance of various LM based processes viz. in the area of bulk liquid membrane (BLM), supported liquid membrane (SLM) and emulsion liquid membrane (ELM) in the separation of LS and mercury using the identified LM is then investigated. Coupled transport of LS and coupled transport of mercury through BLM is carried out to identify the best set of operating conditions and mode of transport that would yield optimum performance of the BLM. The effects of operating conditions, viz. pH, temperature, carrier concentration, stirring speed, initial feed and strip phase concentrations on the transport of LS as well as on mercury are investigated and optimized. Co-transport mode of transfer is found to be more efficient in comparison to counter-transport mode so far as recovery is concerned. It is understood that LM based transport is highly dependent on feed phase pH. The optimized values of pH, carrier concentration and stirring speed in BLM are 2, 4% (v/v) and 500 rpm for LS and 2.5, 1.5%(v/v) and 500 rpm for mercury respectively. The study of LM was continued with a flat sheet supported liquid membrane (FSSLM). The SLM combination DNylon 6,6-TOA-dichloroethaneD was found to be the suitable for both separation of LS and separation of mercury(II). The SLM is found to be stable till 10 hours. It is observed that extraction of LS is increased with increase in concentration of NaOH up to...Item Nash Game Based Mixed H2/H8 Model Predictive Control Applied With Laguerre-Wavelet Network Model(2010) Aadaleesan, PModel predictive control (MPC) is one of the most successful approaches for controlling constrained processes. As MPC design explicitly uses a process model in the computation of the optimal control input, an efficient model, the closed-loop stability and robustness are the major issues in this controller design approach. The scope of this thesis broadly spans two areas: nonlinear system identification and robust MPC design. In nonlinear system identification, a newer kind of Wiener-type nonlinear model, namely Laguerre-Wavelet network model has been developed: the linear dynamic part is formed by the Laguerre filters and the static nonlinear part by the wavelet-network. The performance of the developed model is compared with suitable examples against a similar model of the same class. Various forms of robust MPC approaches have been reported in the literature. On the part of robust MPC design in the present thesis, a novel robust MPC approach is addressed with a game theoretic interpretation. A Nash game approach to mixed H2/H1 Model Predictive Control (NGM-MPC) for linear dynamic systems with actuator saturation is proposed. Two-player non-cooperative game strategy is adopted by solving two separate objective functions, viz., H2 and H1 performance measures, subject to constraints of the system dynamics and the bounded constraints on its control input. The problem ultimately reduces to solving a pair of cross-coupled Riccati equations. Although solving coupled Riccati equations resulting The efficacy of the proposed mixed H2/H1 MPC design is demonstrated with suitable examples by comparing its closed-loop performance and conservativeness with already existing mixed H2/H1 MPC design approach. The infinite horizon state feedback mixed H2/H1 MPC designs are analysed using set-theoretic approach for reasoning out their closed-loop performance and the associated conservativeness issues. The design issues of output feedback mixed H2/H1 MPC design are addressed, where three coupled algebraic Riccati equations are solved simultaneously. Furthermore, the output feedback controller is used with the Laguerre Wavelet Network model for controlling processes with parametric uncertainty, by considering it as disturbance rejection problem. The limitations of the proposed strategy are also discussed. The proposed system identification and robust control techniques are demonstrated on a benchmark process viz., continuous bioreactor. from linear-quadratic games for their exact solution by itself is of theoretical importance, in the present work it has been extended, for the first of its kind, to the regime of receding horizon control....Item Devolatilization of coal of Northeastern India in Argen. Air, and Oxygen -Enriched Air under Fluidized Bed Conditions : Author(2010) Borah, Ramesh ChandraDevolatilization is the first step in most coal conversion processes such as combustion, gasification and liquefaction. It has a significant influence on the subsequent stages of processing. Oxygen-enriched air can increase the combustion efficiency, boiler efficiency, and sulfur absorption efficiency of atmospheric fluidized bed combustion (AFBC) boilers, and other combustion systems which use coal. Devolatilization of five coals having volatile matter in the range of 31 to 41% has been studied in argon, air and oxygen-enriched air under fluidized bed conditions at 1123 K and atmospheric pressure. The experiments with oxygen-enriched air were performed using air containing 30% oxygen. The diameter of the coal particles varied between 4 and 9.5 mm. The variation of devolatilization time (tv ) with particle diameter (dv ) was expressed by the correlation, n tv = Adv , where A and n are the parameters of the correlation. The variation of mass of coal particle with time was described by an exponential correlation, ( ) ( ) 0 0 1 exp m V V V V ct D = + D D D D D D D , where c and m are the correlation parameters. The superficial gas velocity was found to have a significant effect on the rate of devolatilization. The devolatilization rate increased with the increase in the oxygen concentration in the fluidizing gas. Therefore, the parameters of the correlations were further correlated with the superficial gas velocity and oxygen concentration. The correlations developed in this study fitted the mass versus time profiles of the coal particles during devolatilization in a satisfactory manner. The same correlations were found to be appropriate for predicting devolatilization of a batch of coal particles. The correlations developed in this study will be useful for the design of fluidized bed combustors....Item Development and Performance Evaluation of carbon-polymer Composite Bipolar Plate for proton Exchange Membrane Fuel Cell(2011) Kakati, Biraj KumarBipolar plate is akey component of low temperature fuel cells, which may contribute up to 80% of the tatal weight of the proton exchange membrance fuel cell (PEMFC) stack. Different type of materials like metal,coated, graphite,composites etc, are under investigation to develop bipolar with high electrical and thermal conductivity, mechanical strength, flexibility,corrosion resistance, and low hydrogen permeability...Item Performance Characteristics of Electroless Plating Baths for Nickel-Ceramic Composite Membrance fabrication(2011) Bulasara, Vijaya KumarMetal composite membranes made of palladium, silver and nickel have numerous applications in process industries. Amongst these, nickel composite membranes have several applications such as production of ultrapure gases, recovery of TiO2 from waste water streams, new generation supports for dense palladium membranes etc. Electroless plating is one of the most versatile methods adopted for metal composite membrane fabrication. Despite possessing several advantages such as uniformity of coating and ease of scale-up, electroless plating suffers with the basic limitation of very slow deposition rate and hence mass transfer enhancements can be coupled for process efficacy. As opposed to the conventional performance characteristics of electroless plating baths for metalDceramic composite membrane fabrication, this work addresses systematic methodology for the assessment of electroless plating and mass transfer enhanced electroless plating processes for nickelDceramic composite membrane fabrication. Combinatorial performance characteristics of the plating baths are expressed in terms of bath conversion, plating efficiency, selective conversion, nickel plating rate, metal film thickness, average pore size (based on air permeation data), effective porosity (based on air permeation data) and percent pore densification (PPD). Various mass transfer enhancements considered in this work include agitation, sonication and hydrothermal conditions (with and without sonication). Both hypophosphite and hydrazine based plating baths have been assessed for their performance characteristics with a major objective of achieving 100% pore densification using mass transfer coupling effects. A laboratory fabricated symmetric low cost ceramic membrane support having a nominal pore size of plating characteristics are investigated for wide range of nickel solution concentrations (0.04D0.16 mol/L), loading ratios (196D393 cm2/L) and stirrer speeds (0D200 rpm). 275 nm and a porosity of 40% with wider pore size distribution is used as the support (substrate) to obtain deeper insights with respect to the deposition characteristics..Item Development and Characterization of Low Cost Ceramic Membrane for Liquid Phase separation Applications(2011) Monash, PA porous membrane support is prepared with low cost ceramic materials by a simple uniaxial compaction method. The effect of sintering temperature (850-1000DC) on porosity, mean pore size, pore size distribution, shrinkage, flexural strength and pure water permeability was investigated. The raw materials and sintered supports were characterized using thermo gravimetric analysis (TGA), particle size distribution (PSD), X-ray diffraction (XRD) and scanning electron micrograph (SEM) analysis. Based on the characterization results, the support sintered at 950DC (porosity = 44%, flexural strength = 28 MPa, average pore diameter = 1.01 Dm, and water permeability = 4.46D10-6 m/s kPa) is considered as the optimum support (referred as support-I) for membrane applications. Subsequently, the effect of TiO2 (3g and 6g) addition on the properties of the optimized support (support-I) is also examined and no substantial changes is observed for the TiO2 added membrane supports. All the membrane supports are investigated for the separation of oil and BSA from its solution. A higher rejection value of 90-99% is obtained for separation of oil through these supports. However, less rejection is observed for BSA. To improve the separation performance, a selective D-Al2O3 layer (thickness = 2.6 Dm, pore diameter = 5.4-13.6 nm) is developed on the support-I by dip-coating using a stable boehmite sol (davg =30.9 nm) synthesized from inexpensive aluminium chloride. The boehmite sol and the D-Al2O3- clay (clay refers to support-I) composite membrane are characterized with TGA, XRD, SEM, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and liquid displacement techniques. The separation performance of the membrane is investigated using BSA and electrolyte (AlCl3 and MgCl2) solution by varying the process parameters such as pH, applied pressure and feed concentration. The separation results confirm that the rejection and permeability mainly depend on electrostatic attraction/repulsion between the membrane and the solute molecules (BSA, electrolyte). The intrinsic rejection is estimated using Spiegler-Kedem model and the higher rejection (99% for BSA, 72% for MgCl2 and 88% for AlCl3) and permeate flux (3.4D10-5 m/s for BSA, 9.6D10-5 m/s for MgCl2 and 4.4D10-5 m/s for AlCl3) values confirm that the fabricated D-Al2O3-clay composite membrane is potential for liquid phase separation applications. The estimated cost of the membrane (26.04 $/m2) suggests that this could be an alternate for high cost commercial ceramic membranes..Item Preparation cheracterization and Applications of clay Supported Composite Membranes(2011) Jana, SomenLow cost ceramic membranes were prepared by paste casting followed by sintering at various temperatures using natural clay (- 150 mesh) of IIT Guwahati as the main raw material. The mechanical strength of the membrane was successfully increased by addition of small amount of sodium carbonate, sodium metasilicate and boric acid. The pore size of the prepared membrane was found to be 4.58 Dm (for the membrane sintered at 1000 DC). For decreasing the pore size of the membrane, kaolin was mixed with the natural clay in different proportions which resulted in various microfiltration (MF) membranes with a wide range of pore size (4.58 Dm to 0.31 Dm). The membrane pore size and pore density were predicted directly from the particle size distribution of the clay and kaolin and were suitably represented by second-order polynomials. These microfiltration membranes were successfully applied in hybrid processes such as Micellar Enhanced Microfiltration (MEMF) for removal of chromate ions and Advanced Oxidation Process (AOP) followed by MF for the removal of crystal violet dye. With an aim to reduce the pore size of these membranes to Ultrafiltration (UF) range, polymers such as chitosan and polyvinyl acetate were used to coat a thin layer over it using dip-coating method. The glutaraldehyde cross-linked chitosan membrane resulted in a pore size of 14 nm and was successfully applied for the removal of heavy metals (As and Hg) from synthetic groundwater using polymer enhanced UF. Almost 100 % removals were observed for both 500 g LD1 mercury and 1000 g LD1 arsenic. A modified dip coating method was used for preparing the polyvinyl acetate coated membrane whose pore size was found to be 9 nm. This membrane was successfully applied to fractionate lysozyme and ovalbumin from chicken egg white. An overall rejection of 94 % ovalbumin and transmission of 95% lysozyme was achieved. Another mixed matrix membrane was prepared using one polymer (cellulose acetate) and one inorganic precursor (LTA zeolite) with a pore size of 10 nm and the membrane efficiency was tested by rejection of bovine serum albumin (BSA). An overall BSA rejection of more than 95% was obtained....Item Studies on free surface flow of concentrated suspension in open channels and rotating cylinders(2011) Kumar, A. AshokFree surface flow of concentrated suspension has been studied in open channel and rotating cylinders at low Reynolds number flow. In this work, the wall slip was characterized through flow visualization experiments. The conventional rheometers and Couette cells has been used for determining slip velocity for suspension of smaller particles. However, characterization of wall slip for suspensions of larger particles such as debris flow, concrete mixtures etc. cannot be performed in conventional rheometers. For such systems we have provided the technique of determining wall slip from the velocity profile measurements in open channel flow. To measure the velocity profiles in open channel flow, we have used the method of particle image velocimetry (PIV). Experiments have been carried out under the conditions of slip and no-slip conditions and velocity and surface corrugation patterns have been analyzed. Our study showed that the wall slip only changes the velocity profile and it has no apparent effect on the surface corrugation. This is because the slip layer affects are confined near the wall, the bulk shape of the surface remains unchanged. To measure the height of corrugation structures we have performed measurements in velocity-vorticity plane. The interface was seeded with hollow glass balloons which floated on the surface and their location was determined using an edge detection technique. Position of maximum gradient of image intensity determines the interface height. By comparing the interface profile between two consecutive image frames we determined the vertical velocity of the interface. It is observed that interface fluctuation increases linearly with increase in shear rate. The perturbation of the interface in the velocity-vorticity plane increases with increase in particle concentration until an optimum particle concentration, and thereafter the height of the free surface corrugation decreases continuously. These results also support the findings from the analysis of spectra of refracted light from the free surface. It is observed that the interface fluctuation increases with increase in particle size for a given suspending fluid whereas it decreases with increase in the viscosity of suspending fluid for suspension of given particle size. In another study we have, investigated the band formation during free surface flow of concentrated suspension of bi-dispersed particles in rotating cylinders. In this work, we have studied the behavior of bi-dispersed neutrally and non-neutrally buoyant suspension of non-colloidal particles in a horizontally rotating cylinder separately. Experiments were carried out at various filling fractions and angular speed of the cylinder. A number of distinct patterns of particle size segregation were observed for various conditions. At low rotation speeds, the gravity force on the particles dominates and we observe that alternate bands of larger and smaller particles completely fill the tube. These bands also move axially and merge to form bigger bands. The number of bands decreases with rotation speed whereas the band width increases. At higher speeds the bands of smaller particles are disturbed by the bigger particles and no stable axial segregation is observed. On the other hand, at much higher speed when the centrifugal force on the both smaller and larger particles dominates, the particle bands segregate from the suspending fluid..Item Simultaneous Desulphurization and Denitrification of Diesel Oil Using Ionic Liquids: Quantum Chemical Predictions and Experiments(2011) Anantharaj, RAb-inito studies were carried out with mixtures containing ionic liquid with thiophene and pyridine for studying the simultaneous interaction. Global scalar properties such as HOMO/LUMO energies, HOMO-LUMO energy gap, chemical hardness, chemical potential, electronegativity, global hardness, global softness and electrophilicity index were determined for clusters containing ionic liquids with thiophene and pyridine. Ionic liquids containing: 1-butyl-3-methylpyrrolidinium [BUMPYR], 1-benzyl-3-methyimidazolioum [ BeMIM] and 1-butyl-3-methylpyridinium [BUMPY] cations combined with inorganic anions containing fluorine ([BF4] and [PF6]) were studied in this work. [BeMIM][BF4] (1-benzyl-3-methyimidazolioum tetrafluoroborate) with a HOMO-LUMO energy gap of 0.1882 eV was found to be the most effective IL. Further a ranking based on all the mentioned scalar parameters also pointed out [BeMIM][BF4] to be the most desirable IL. The overall ranking after taking into considerations all factors followed: [BeMIM][BF4] > [BUMPYR][BF4] > [BUMPY][PF6]> [BUMPY][BF4] > [BUMPYR][PF6]. To validate the findings, infinite dilution activity coefficients were predicted using the quantum chemical based COSMO-RS methodology which gave the same trend as observed using scalar properties. ......Item Product Distribution and Mechanistic Aspects in Pyrolytic Decomposition of Some Commodity Plastics(2012) Hujuri, UjwalaRecent years seen remarkable demand for plastic goods in varied fields of application. with the rise in the use of plastics there is a parallel rise in the generation of wasre plastics. due to the non-biadegradable nature of most of the plastic, their presence in the waste stream has become a major concern. Pyrolysis of plastics offers a technological solution to the management of this voluminous waste which otherwise , would end up in landfills..Item Synthesis and Application of Novel Adsorbents for Wastewater treatment(2012) Anandkumar, J.Adsorptive removal of certain tannery wastewater pollutants and other industrially important heavy metals, using newly synthesized adsorbents from waste Bael shell (BS) and Tannery residual biomass (TB), is the main theme of this thesis. Adsorptive removal has been advocated to be a better option to eliminate organic and inorganic pollutants both single and multiple forms with high efficiency as compared to other popular methods for wastewater treatment. Cr6+, phenol, o-cresol, rhodamine B and methylene blue have been identified as critical inorganic and organic contaminants that are found in various industrial effluents especially in tannery effluent. In addition to this, Pb2+, Ni2+ and Sr2+ are few other important heavy metals present in the effluents which are used for fabrication many of commercial products in industries. Although, past researchers have mostly studied the adsorption of organic or inorganic pollutants only in single form using commercially available and other biosorbents, but these pollutants are usually exist together in industrial wastewater. It has been studied and reported in this thesis that the above mentioned/targeted organic and inorganic pollutants are successfully removed with high adsorption capacity both in single and mixed form using synthesized novel adsorbents. Hence, to prepare this novel multiple usage adsorbents from the locally available industrial waste materials (BS and TB), three activation methods such as thermal, chemical and thermochemical activation were employed in this thesis. The utilization of these industrial waste materials as useful adsorbents may helpful to reduce the cost of solid waste disposal and recycle for their own and other industrial wastewater treatment. Initially, synthesized adsorbents of BS and TB at various conditions were employed for BET surface area optimization followed by preliminary performance evaluation test (PPET) with the targeted pollutants to identify the potential adsorbent for the particular pollutant removal. BET results of synthesized adsorbents revealed that thermochemically activated BS and TB using H3PO4 had high surface area of 1954 and 892 m2/g. However, PPET results showed that thermochemically activated BS and TB using H3PO4 (BSAC and TBAC), chemically activated BS and TB using H2SO4 (SBS and STB) and TB using HCl (HTB) had high adsorption capacity with targeted pollutants. Therefore, BSAC, TBAC, SBS and HTB were chosen as best adsorbents for elaborate adsorption studies with the selected contaminants from the PPET..