363 research outputs found

    Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

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    Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

    Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

    Get PDF
    Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

    The Influence of Education Level, Training, and Performance Appraisal Towards Career Development (Study: PT. Angkasa Pura 1 Manado)

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    Career development is a condition that indicates the status of a person improvement in an organization in a career path that has established within the organization concern. There are several factors that can make employee achieve their career development include education level, training, and performance appraisal. The objective of the study is to know the influence of education level, training, and performance appraisal towards career development at PT. Angkasa Pura 1 Manado. Data was analyzed quantitatively and through use of statistical package for social scientists (SPSS). The research method that used in tihs research is ordinal regression analysis using random sampling with the sample of the respondents is 58 samples of all the employees at PT. Angkasa Pura 1 Manado. The result of this study shown that education level and training have no significant influence towards career development, and performance appraisal has significant influence towards career development. To management of company, researcher suggests to keep enhancing the performance appraisal and more consider the background of education and improve training program for better human resource. Keywords: education level, training, performance appraisal, career developmen

    Harmonic reduction of a single-phase multilevel inverter using genetic algorithm and particle swarm optimization

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    Inverter play important role in power system especially with it capability on reducing system size and increase efficient. Recent research trend of power electronics system are focusing on multilevel inverter topic in optimization on voltage output, reduce total harmonics distortion, modulation technique and switching configuration. Standalone application multilevel inverter is high focused due to the rise of renewable energy policy all around the world. Hence, this research emphasis on identify best topology of multilevel inverter and optimize it among the diode-clamped, capacitor clamped and cascaded H-bridge multilevel inverter to be used for standalone application in term of total harmonics distortion and voltage boosting capability. The first part of research that is identify best topology multilevel inverter is applying sinusoidal pulse width modulation technique. The result shown cascade H-bridge give the best output in both total harmonics distortion (9.27%) and fundamental component voltage (240 Vrms). The research proceed with optimization with fundamental switching frequency method that is optimized harmonic stepped waveform modulation method. The selective harmonics elimination calculation have adapt with genetic algorithm and particle swarm optimization in order to speed up the calculation. Both bio-inspired algorithm is compared in term of total harmonic distortion and selected harmonics elimination for both equal and unequal sources. In overall result shown both algorithm have high accuracy in solving the non-linear equation. However, genetic algorithm shown better output quality in term of selected harmonics elimination where overall no exceeding 0.4%. Particle swarm optimization shows strength in finding best total harmonics distortion where in 7-level cascaded H-bridge multilevel inverter (m=0.8) show 6.8% only as compared to genetic algorithm. Simulation for 3-level, 5-level and 7-level for each multilevel inverter at different circumferences had been done in this research. The result draw out a conclusion where the possibility of having a filterless high efficient invert can be achieve

    3-(3-Meth­oxy­benzo­yl)-1,1-diphenyl­thio­urea

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    The thiono and carbonyl groups in the title compound, C21H18N2O2S, adopt an anti disposition with respect to the central C—N bond. The diphenyl­amine rings are twisted relative to each other by a dihedral angle of 82.55 (10)°. The 3-meth­oxy­benzoyl fragment is twisted relative to one of the diphenyl­amine rings, forming a dihedral angle of 74.04 (9)°. In the crystal, pairs of inter­molecular N—H⋯S hydrogen bonds link the mol­ecules into centrosymmetric dimers, forming columns parallel to the a axis

    Preparation and Characterization Of Untreated Waste Palm Oil/Diesel Fuel Blend

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    Some diesel engines can run on some kinds of vegetable oil under some conditions without problems. To use vegetable oils in diesel engine without modification, it is necessary to make sure that the vegetable oils properties must be similar to diesel fuel. In this study, palm oil that has been used several times for frying purposes is investigated for the utilization as an alternative fuel for diesel engines. The waste palm oil has a variety of qualities, possess properties different from that of neat oils. Higher impurities of the used oils make them different from neat vegetable oil. The high viscosity of the waste palm oil was decreased by blending with diesel. Two different previous uses of waste palm oil were blend with diesel. The blends of varying proportions of waste palm oil and diesel were prepared, analyzed and compared with diesel fuel and the waste palm oil ethyl ester. The properties of the blends such as heating value, viscosity, specific gravity, etc. were determined. It was found that blending waste palm oil with diesel reduces the viscosity and different previous uses of waste palm oil significantly affected the properties of the blended fuels. From the properties test results it has been established that blends containing 5 to 40% of waste palm oil in diesel yielded the properties closely matching that of diesel

    Mechanical properties of caco3 extracted from cockle shell with high density polyethylene (HDPE) for biomaterials in bone substitute application

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    This study was conducted to produce CaCO3 powder extracted from cockle shells as bioceramic materials which later combined with high density polyethylene (HDPE) as the polymer to produce composite as the final product. For CaCO3 clarification, the powder form of bioceramics was analyzed using FTIR, SEM and EDX analyses. Then, the composites produced were tested for mechanical properties via tensile and hardness tests. Firstly, the wasted cockle shells were all washed to remove dirts and soaked in regular water overnight before left to dry at room temperature. Then, they were all ground up between range 100 – 200 µm several times until the required size were obtained. The spectrum for FTIR showed identical result as previous work at reading 857.22cm-1 which represent vibrational bonds that can be attributed to the characteristics of external plane bending vibration of carbonate. After the confirmation, it was added to the melted HDPE to produce stronger composite via injection moulding method. Injection moulding process was to produce the sample into the shape of dumbbell to perform mechanical tests, tensile and hardness test with three parameters for each weight ratio. It could be concluded that pressure, velocity and temperature affecting the hardness of samples. In this research, the greatest value of Young’s modulus and maximum force which are 852.2 MPa and 271.457 kN, respectively. In conclusion, cockle shell could become great biomaterial as it provide good in mechanical properties. Furthermore, the source also abundantly available and with the fully usage of this waste to something more useful, it is able to reduce contamination to the earth. Then, the combination with any polymer is able to produce strong composite that could apply in any field. For this research, the composite is focus in biomaterial usage, especially in orthopaedic field for bone implant. For instance, CaCO3 are proved to be function at higher temperature, and further future works might be required to search the maximum temperature that this material could achieve

    SYNTHESIS AND CHARACTERIZATION THE COMPOSITE ORGANIC-INORGANIC MEMBRANE USING SOL-GEL PROCESS FOR PROTON EXCHANGE MEMBRANE FUEL CELL (PEMFC)

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    Nafion-silicon oxide (SiO2)-phosphotungstic acid (PWA) composite membrane has been synthesized for medium temperature Proton Exchange Membrane Fuel Cell (PEMFC) application using sol-gel method. X-ray diffraction (XRD) was used to determine saturated absorption of PWA in the silica matrix. A transparent film was achieved at annealing temperature of 140oC over 10 hours duration. The film than was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). The SEM and TEM results indicated homogenous structure of the Nafion-SiO2-PWA composite membrane with SiO2 and PWA particles size less then 10 nm. X-Ray Diffraction (XRD) result showed that the maximum loading of PWA in the SiO2 matrix is in the ratio of PWA/SiO2 equal to 0.45 (wt./wt.). The vibration absorption peak of Si-O-Si bond at 800 cm-1 and W-O-W at 755 cm-1 were observed thus indicated the inorganic compound was embedded in the Nafion matrix and did not leach out after washing treatment using acid and base solutions

    Exsolution enhancement of metal-support co oxidation perovskite catalyst with parameter modification

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    This study aimed to further tune the capability of active metal exsolution onto the surface of the CO oxidative perovskite catalyst La0.7Ce0.1Co0.3Ni0.1Ti0.6O3 by tuning the reducing parameter. Under same calcination temperature of 800℃, XRD analysis shown that the precursors with calcination duration of 6 hours (S2T8H6) was able to achieve similar crystalline structure to those with calcination duration of 12 hours (S2T8H12). In order for the active metal (CoNi) to be exsolved onto the perovskite surface, reducing parameter such as temperature and duration are deemed crucial to the reduction process. The exsolution of the active metals was observed when the samples were treated under reducing condition with varying temperatures of 550℃ and 700℃ and duration from 200 to 300 minutes. Through comparison with their EDX readings, S2T8H6 treated under 700℃ and 300 minutes (S2T8H6-R7H5) achieved the highest weight percentage of surface Cobalt and Nickel of 3.83 and 2.81. It was clear that by tuning the temperature and duration of reduction, the exsolution of the active metals onto the surface of the perovskite could be improved resulting in better exposure and dispersion of active metals onto the surface of catalyst
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