Laxminarayan Institute of technology

The doped KNbO 3 single crystal have been prepared using flux method by taking K 2 CO 3 and Nb 2 O 5 as starting materials, in the molar ratio of 1.2:1 with an impurity of Al 2 O 3 (200mg).The good quality single crystals were obtained by this method. The sample are partially transparent suitable for optical properties. The detailed study of structural parameters, dielectric and Hysteresis loop studies were carried out in this paper. The prepared sample has been characterized by X-Ray diffraction method to determine lattice parameters. The material is orthorhombic with lattice parameters as: a= 5.69399Å, b=3.96801 Å, and c= 5.71852 Å. The dielectric property shows the possibility of phase transition at high temperature. The material has high value of dielectric constant at Curie temperature of about 435°C.The hysteresis curve observed at room temperature todetermine various parameters particularly, the spontaneous polarization (Ps), remanent polarization (Pr) and coercive field (Ec). The value of spontaneous polarization is determined from the hysteresis curve 9.632 × 10-5 µC/cm 2 at E = 45.6V/cm. The other parameters i.e. remanent polarization (Pr) is equal to 1.60×10-5 µC/cm 2 , and coercive field (Ec) is 24.85 V/cm.

The doped KNbO3 single crystal have been prepared using flux method by taking K2CO3 and Nb2O5 as starting materials, in the molar ratio of 1.2:1 with an impurity of Al2O3 (200mg). The good quality single crystals were obtained by this method. The sample are partially transparent suitable for optical properties. The detailed study of structural parameters, dielectric and thermal properties were carried out in this paper.  The prepared sample was characterized by X-Ray diffraction method to determine lattice parameters.  The material is orthorhombic at room temperature having a= 5.6880Å b=3.9706 Å c= 5.7150 Å. The dielectric properties shows the dielectric anomaly observed at low frequencies with increasing temperature through dielectric constant measurement. The material has high value of dielectric constant at Curie temperature of about 435°C which is confirmed by DTA curve.

The doped KNbO 3 single crystal have been prepared using flux method by taking K 2 CO 3 and Nb 2 O 5 as starting materials, in the molar ratio of 1.2:1 with an impurity of Al 2 O 3 (100, 200mg). The good quality single crystals were obtained by this method. The sample are partially transparent suitable for optical properties. The detailed study of structural parameters, dielectric and thermal properties were carried out in this paper. The prepared sample was characterized by X-Ray diffraction method to determine lattice parameters. The material is orthorhombic at room temperature. The dielectric properties shows the dielectric anomaly observed at low frequencies with increasing temperature through dielectric constant measurement. The material has high value of dielectric constant at Curie temperature of about 435°C which is confirmed by DTA curve.

The samples of Fe-doped KNbO3 single crystal have been prepared by the flux method by using K2CO3 and Nb2O5 as starting materials, having molar ratio 1.2:1 with an impurity Fe2O3 (10mg), the prepared samples were characterized by X-ray diffraction method. Dielectric properties of KNbO3 have been investigated in the temperature range 28-500°C at different frequency in the range 100 Hz, 1 Hz, 10 kHz, 100 kHz. It is observed that electrical conductivity increases with increasing temperature. Near the transition temperature, electrical conductivity of these sample shows anomalous behaviour. Prepared sample shows orthorhombic structure at room temperature.

Synthesis of Fe doped KNbO3 single crystals by flux method is reported here. The effect of Fe-doping on phase transition temperatures of KNbO3 single crystals was investigated using dielectric studies. The phase transition temperatures were found to be 225 o C and 425 o C which almost same as reported by others. The domain studies were carried out using metallurgical microscope and it shows the presence of 60 o and 90 o domains in the grown crystals.

Nucleation of domain wall has beenfound on the naturally grown surfaces of KNbO3single crystals. It is studied by using trinocular microscopy methods. The grown surface of the crystal identified as 60°&90° domain wall this has same interaction and orientations like earlier observed. The complex domain pattern observed in the wall portion like 60°, 90° 180°walls. Also,few grain boundaries in domain wall portions have been found. The type of domain walls that can occurs in ferroelectric crystal depend on the symmetry of both non ferroelectric and ferroelectric phases of the crystal.

The production of high grade jet fuels from vegetable oils is an issue of special interest to refineries. The conversion process involved hydrotreating (i.e. hydrodeoxygenation and hydrodecarboxylation) of the oils followed by subsequent hydroisomerization. The paper focuses on hydrotreatment of vegetable oil, possible reaction mechanism and catalyst used for the process. Catalysts based on Nickel and Molybdenum supported on oxides is considered very active for the hydrotreating process then Platinum, Palladium and Ruthenium on zeolites. Change from noble metals to transition metals as the medium of catalyst for hydrotreatment of oil has also improved the overall process.

The world energy requirement is mainly provided by petroleum products. Its, extensively utilization has led to climate change, environmental pollution, and health problems. To reduce these adverse affects, it is necessary to enhance the use of renewable energy sources. Among many renewable energy sources biodiesel is one such alternate. Biodiesel is produced by trans-esterification where vegetable oils react with alcohol in present of catalyst such as (NaOH, KOH). In India, there are many trees bearing oil like mahua (madhuca indica), jatropha, and karanja (pongamia pinnata) etc. Among these species, which can yield oil as a source of energy in the biodiesel, mahua oil has been found to be one of the most suitable species. Conventionally, Biodiesel was produced in batch reactor by trans-esterification process and optimum condition were found to be 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and minimum 55-60 0 c temperature and minimum 1 hr reaction time. A Novel reactor oscillatory baffled reactor has been designed and fabricated. The optimum conditions for trans-esterification reaction in OBR were as 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and maximum 10 min reaction time. The different properties of biodiesel were analysed as per ASTM standards. And the result shows that biodiesel produced by oscillatory baffled reactor are cheaper and has better properties as compared to conventional batch reactor.

—globally there is renewed interest in the production of alternate fuels in the form of ethanol and biodiesel. This is mainly due to the realization that crude oil stocks are limited hence the swing towards more renewable sources of energy. The addition of alcohol to diesel fuel simultaneously decreases cetane number, high heating value, aromatics fractions and kinematic viscosity of alcohol blended diesel fuels and changes distillation temperatures. The stability and physiochemical properties of different diesel-alcohol blends and their composition depends on the solubility properties of the alcohols which are mainly dependent on the carbon chain length of the alcohol, their water content, additives, temperature and also on the hydrocarbon composition of the diesel fuel. Also various other physical properties such as stability, density, kinematic viscosity, flash point, surface tension, lubricity, safety and materials compatibility of most stable blends (both ethanol and butanol as per ASTM standards) also need to be considered. The blend of ethanol diesel of 5% was found to be more stable compared to other blends.

Isobutyl acetate forms the binary azeotrope with Isobutyl alcohol. Extractive distillation is the method of separating close boiling azeotrope in presence of some suitable solvent or the mixture of the solvents. In case of separation of Isobutyl acetate and isobutyl alcohol the solvents used can be n-butyl propionate, dimethyl acetamide, 1-hexanol, and Dimethyl formamide or dimethyl sulfoxide. The separation of Isobutyl Alcohol-Isobutyl Acetate azeotropic mixture, we have carried out the simulation by means of package using commercial software CHEMCAD. The simulation and economic evaluation for the extractive distillation using above solvents using CHEMCAD package shows that n-butyl propionate is the best solvent among these solvents. The Isobutyl alcohol-Isobutyl acetate mixture is also pressure sensitive. So, Vacuum distillation can also be used to recover pure components with a simple change in pressure. But the cost requires for the vacuum distillation for the same separation is comparatively large than the extractive distillation using n-butyl propionate as a solvent.

The world energy requirement is mainly provided by petroleum products. Its, extensively utilization has led to climate change, environmental pollution, and health problems. To reduce these adverse affects, it is necessary to enhance the use of renewable energy sources. Among many renewable energy sources biodiesel is one such alternate. Biodiesel is produced by trans-esterification where vegetable oils react with alcohol in present of catalyst such as (NaOH, KOH). In India, there are many trees bearing oil like mahua (madhuca indica), jatropha, and karanja (pongamia pinnata) etc. Among these species, which can yield oil as a source of energy in the biodiesel, Pongamia pinnata has been found to be one of the most suitable species. Conventionally, Biodiesel was produced in batch reactor by trans-esterification process and optimum condition were found to be 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and minimum 55-60 0 c temperature and minimum 1hr reaction time. A Novel reactor oscillatory baffled reactor has been designed and fabricated. The optimum conditions for trans-esterification reaction in OBR were as 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and maximum 10 min reaction time. The different properties of biodiesel were analysed as per ASTM standards.

Today about 80% of world energy requirement is provided by petroleum products. Its, extensive utilization has led to climate change, environmental pollution, and health problems. To reduce these effects, it is necessary to enhance the use of renewable energy sources. Among many renewable energy sources biodiesel is one such alternate. Biodiesel is produced by reacting oil (mahua oil) with alcohol in present of base catalyst such as (NaOH, KOH) by a process known as trans-esterification. For the optimization of biodiesel production, various parameters have to be considered such as oil/alcohol ratio, temperature, reaction time, catalyst, nature of catalyst (homogeneous, heterogeneous), and type of process (single, two step process). This can be achieved with experience and research in the corresponding field but these things require enamors time. There is a method based on statistics and mathematics which can optimize the process parameters in very short time, called RESPONSE SURFACE METHODOLOGY (RSM). The optimum condition for the biodiesel production using RESPONSE SURFACE METHODOLOGY (RSM) is 92.7 ml mahua oil with 1:12 methanol/oil molar ratio, 0.4wt of catalyst and 10 minute reaction time in an oscillatory baffled reactor (OBR).

The world energy requirement is mainly provided by petroleum products. Its, extensively utilization has led to climate change, environmental pollution, and health problems. To reduce these adverse affects, it is necessary to enhance the use of renewable energy sources. Among many renewable energy sources biodiesel is one such alternate. Biodiesel is produced by trans-esterification where vegetable oils react with alcohol in present of catalyst such as (NaOH, KOH). In India, there are many trees bearing oil like mahua (madhuca indica), jatropha, and karanja (pongamia pinnata) etc. Among these species, which can yield oil as a source of energy in the biodiesel, mahua oil has been found to be one of the most suitable species. Conventionally, Biodiesel was produced in batch reactor by trans-esterification process and optimum condition were found to be 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and minimum 55-60 0 c temperature and minimum 1 hr reaction time. A Novel reactor oscillatory baffled reactor has been designed and fabricated. The optimum conditions for trans-esterification reaction in OBR were as 1:9 oil to methanol ratio, 0.75% w/w KOH base catalyst, and maximum 10 min reaction time. The different properties of biodiesel were analysed as per ASTM standards. And the result shows that biodiesel produced by oscillatory baffled reactor are cheaper and has better properties as compared to conventional batch reactor.

Today about 80% of world energy requirement is provided by petroleum products. Its, extensive utilization
has led to climate change, environmental pollution, and health problems. To reduce these effects, it is
necessary to enhance the use of renewable energy sources. Among many renewable energy sources biodiesel
is one such alternate. Biodiesel is produced by reacting oil (mahua oil) with alcohol in present of base
catalyst such as (NaOH, KOH) by a process known as trans-esterification. For the optimization of biodiesel
production, various parameters have to be considered such as oil/alcohol ratio, temperature, reaction time,
catalyst, nature of catalyst (homogeneous, heterogeneous), and type of process (single, two step process).
This can be achieved with experience and research in the corresponding field but these things require
enamors time. There is a method based on statistics and mathematics which can optimize the process
parameters in very short time, called RESPONSE SURFACE METHODOLOGY (RSM). The optimum
condition for the biodiesel production using RESPONSE SURFACE METHODOLOGY (RSM) is 92.7 ml
mahua oil with 1:12 methanol/oil molar ratio, 0.4wt of catalyst and 10 minute reaction time in an oscillatory
baffled reactor (OBR).